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K.U.C.J

Al-Kut University College Journal Refereed Scientific Journal Published by

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ii

Special Issue/ The First International Scientific Conference No:Second 29 - 30 April 2017Al Kut University College

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Special IssueThe First International Scientific Conference

Issue

Two

mailto:[email protected]


http://www.alkutcollege.com/

Content of Second Issue

The First International Scientific Conference / Al-Kut University College

No: The Title of the Paper and the Names of researchers

Page

1. Mathematical Model of FHXW Branching Type with Hyphal Death Dr Ahmed Shihab Hamid and Dr Ali Hussein Shuaa ……………………………………………………….

1

2. Extract the Artifact signals from EEG-BCI system based on Blind Source Separation techniques Dr. Ahmed Kareem Abdullah and Dr. Ali Abdul Abbas Abdullah Albakri ……………………………

16

3. Estimation of TSH, T3 & T4 in beta-thalassemia major patients in Kirkuk city Fadheelah Salman Azeez ……………………………………………………………………….

29

4. Assessment the knowledge of patients with Heart Failure in Wasit Ihsan H. Zainel ………………………………………………………………………………………………..

39

5. Study Some Physical And Mechanical Properties For Alumina – Zirconia Composite Ghazi K. Saeed, F. A. Chyad and R. H. Yousif ……………………………………………………………..

55

6. Experimental And Theoretical Estimation Of Hourly Based Solar Irradiance In Baghdad Khalid S. Shibib, Mohammed A. Munshid, Dr.Mohammed Sellab Hamza And Haneen D. Jabbar……

65

7. Preparation and Study the Electrical Properties of CuS Nano crystalline Thin Films. Dr. Suad M.Kadhim, Dr.Ayad Z.Mohammed, and Dr.Talib Z.al-Mosawi……………………………….

79

8. Size Dependence of the Dielectric Susceptibility of Nonsolid Amorphous Silicon Hussein K. Mejbel, Nadhal M. Abdul-Ameer and Moafak C. Abdulrida …………………………….

94

9. Design and construction of Optically intelligent system to monitor soil moisture to control the operations of irrigation of agricultural land. Dhafir A.Dhahir, Bushra R .Mahdi ,Ahmed A.Hmad , Naser M.Hadi ,Ahmed K.Ibrahim …………...

102 10. Glucose Concentration Measurement by Fiber Optic Sensor

Mohammed Suham Sada , Nahla A. Aljaber , Farah Zamil Hassan, Dr. Bushra R Mahdi ……...........

108 11. Measurement of Plasma Temperature From The Iron lines Appeared of alloy (low-carbon

steel) Using Laser-Induced Breakdown Spectroscopy (LIBS) Eng. Mohannad H. Hussein and Dr. Alaa H. Ali ………………………………………………………...

117 12. Study The Structural And Morphological Properties Of Nano Structure Zinc Oxide (ZnO) Thin

Films Prepared By RF Magnetron Sputtering Abdul Hussein K. Elttayef, N.N.Jandow and Abass Maijed ……………………………………………..

126 13. Preparing nanostructure SnO2 powder by using APCVD

Nagham T. Ali , Talib Z. T. AL-Mosawi …………………………………………………………………….

133

iv

First International Scientific Conference 29 – 30 April 2017 2017نیسان 30 – 29المؤتمر العلمي الدولي األول / ISSN: Issue two / Al-Kut University College 7419 - 2414 الثاني / العددكلیة الكوت الجامعة

Mathematical Model of FHXW Branching Type with Hyphal Death

Dr Ahmed Shihab Hamid 1,Dr Ali Hussein Shuaa 2 1 Ministry of Education

2 Department of Mathematics,College of Education, Wasit University, Wasit , Iraq

ABSTRACT A mathematical description of growth and branching in fungi can be derived in

terms of continuous variables such as densities of filaments and tips. The general

concept of continuum modeling yields the following equations of fungal growth in

which a balance is kept for the accumulation of hyphal filaments and their tips. Hyphae

are immobile. They are created only through the motion of tips-essentially the trail left

behind tips as they moves. The rate of local length accumulation depends on the number

of tips and branches present as well as on their rate of motion. This suggests the

following equation

(1.1)p nv dt

∂= −

∂

Here, the variables are as follows: (x, t)p p= : hyphal density in unit of filament

length per unit area;

(x, t)n = : tip density (number per unit area ); v : tips extension rate; (p)d d= :

hyphal death rate. Tips do undergo motion so that the flux of tips enters into the

equation for tip densities. Assuming that tip growth is a directed motion, in one

dimension this equation would take the form :

(nv) (p,n) (1.2)n

t xδ∂ ∂

= − +∂ ∂

Where (p,n)δ δ= - net creation of tips.

Keywords Hyphal death, Dichotomous branching, Lateral branching, Tip-hypha anastomosis, Tip-tip anastomosis, Tip death, Tip death due to overcrowding.

1- Introduction

In this paper, we will study a new type of branching of fungal growth.

From the basic tip - growth mechanism: a number of tips n growing at the

rate v (in length per unit time) gives rise to a hyphal accumulation rate of

nv (in hyphal length per unit time). [2] discussed and analyses the above

1


model when (p,n) 0d = for a variety of biologically relevant functions (p,n)δ .

More generally, we can describe hyphal growth by the system below:

This second balance equation for tip densities accommodates the fact

that tip move (with flux Jn nv= ) and are moreover created by branching

or eliminated by anastomosis [1]. The ratio of hyphal length per tips is

called the hyphal growth unit, with flux Jn nv= .

We investigated from effect hyphal death on development of fugal

network, when 1(p) kd pγ= .

Now we will focus for new work as this model (FHXW Branching Type

with Hyphal Death ) :

1

2 21 3 2 1 2 3

.... (1.4)nv

tn nv n n n nt x

ρ γ ρ

α α α ρ β β ρ β ρ

∂ = − ∂∂ ∂ = − + − + − − −∂ ∂

For solving any system in mathematical with many parameters we need to

reduce this parameters, this operation called non-dimensionalisation. The

branching and biological type for (p,n)δ shows as a table below:[2]

(p)(1.3)

( ) (p,n)

n

n

p J dt

Jnt x

δ

∂ = − ∂∂∂ = − +∂ ∂

2


Table : illustrate biological type of branching and version for every case.

2. Non-dimensionalisation

Some equations contain many parameters and can be difficult to find

accurate values for these parameters that resort to non-dimensionalisation

as in the following example:

In the system below (1.4).

Branching Biological type Sym

bol

Version Parameters description

Dichotomous

branching

Y 1nδ α= 1α is the number of tips

produced per tip per unit

time

Lateral branching

F

2 pδ α= 2α is the number of

branches produced per unit

length hypha per unit time

Tip-hypha anastomosis

H

2npδ β= − 2β is the rate of tip

reconnections per unit

length hypha per unit time

Tip-tip anastomosis W 21nδ β= −

1β is the rate of tip

reconnections per unit time

Tip death

T

3nδ α= − 3α is the loss rate of tips

(constant for tip death)

Tip death due to

overcrowding

X

23 pδ β= −

3β is the rate at which

overcrowding density

limitation) eliminates

branching

Hyphal death D 1d pγ=

1γ is the loss rate of

hyphal (constant for

hyphal death)

3


To facilitate the analysis of this system and to assist in its numerical

To do so, we choose [3]dimensionalise the equations. -integration, we non

a reference time T , a reference length scale x and reference scales for

hyphal density, p , and tip density, n . Setting

* ppp

= , * nnn

= , * ttT

= , and * xxx

= (1.5)

And substituting into (4.6) yields

1

1

31 2

2 22 231 2

* ( ) * ( ) *** *( ) ( ) * ( ) * * (1.6)* *

( ) * ( ) * * ( ) *

Tpp Tvn n pt p p

T nT n T pn Tvn n n n pt x n x n n n

T pT n T pnn n p pn n n

γ

αα α

ββ β

− ∂= − ∂

∂ ∂= − + − + ∂ ∂

− − −

2

Now, setting x Tv= and p xn= , (1.6) becomes

21 3 2

2 2 2 21 2 3

* ( ) * *** *( ) ( ) * ( ) * ( ) * ... (1.7)* *

( ) * ( vn) * * ( ) *

p Tv n dpt Tvn x n T n T n vT pt x x

T n n T n p T v p p

α α α

β β β

∂ = − ∂ ∂ ∂ = − + − + ∂ ∂

− − −

,

where 1

1Tγ

= , 1Tdp pγ

= and on cancelling get,

1

2 21 3 2 1 2 3

nvtn nv n n n nt x

ρ γ ρ

α α α ρ β β ρ β ρ

∂= −

∂∂ ∂

= − + − + − − −∂ ∂

4


31 22

1 1 1

2 231 22 2

1 1 1

* * *** * ( ) * ( ) * ( ) * ..... (1.8)* *

vn( ) * ( ) * * ( ) *

p n dpt

vn n n n pt x

v pn n n p p

αα αγ γ γ

ββ βγ γ γ

∂= −

∂ ∂ ∂

= − + − + ∂ ∂

− − −

The remaining choice of p or n depends on the exact branching kinetics

chosen.

In this chapter we will study two cases:

1- FHXW type with hyphal death , that mean our model becomes

FHXWD

2- FHXW type without hyphal death.

2.1 New Branching Type with Hyphal Death

In this section, we will study a new type of branching of fungal growth,

that’s mean (p, n) F H W X .....(1.9)δ = + + +

Where, F: Lateral Branching,

H: Tip – Hypha Anastomosis,

W: Tip-tip anastomosis,

X: Tip death due to overcrowding.

The model system for FHXWD is:

2 232 2 12 2 2

1 1 1 1

* * ** (1.10)n* * ( ) * ( ) * * ( ) n* ( ) p** *

p n pt

vpv vnn n p n pt x

βα β βγ γ γ γ

∂ = − ∂ ∂ ∂ = − + − − −

∂ ∂

5


After dropping stars, choosing 2

2

n αβ

= , and 2 1 1

2 3

pv

α β γβ β

= the system (1.10)

becomes

2 2.... (1.11)

(1 n) (n p )

p n ptn n pt x

α β

∂ = − ∂∂ ∂ = − + − − +∂ ∂

Where

22

1

vααγ

= and 2 1

2 1

α βββ γ

=

Some techniques to solve above system as:

2-2 The stability of solution

In this section, we will illustrate stability of system (1.11), as:

The solution of these equations, we will find values of (p,n) , the steady

state are :(0,0) unstable node, and ( , )2 2

α αα β α β+ +

: saddle point, see Fig (1)

2 2

0... (1.12)

(1 n) (n p ) 0n p

pα β

− =

− − + =

6


Figure(1.1) : The (np)-plane: note that a trajectory connects the unstable node (0, 0) to the saddle point

( , )2 2

α αα β α β+ +

where ( 1, 1)α β= = .

2-3 Traveling wave solution

Hence we seek travelling wave solutions to (1.11). A mathematical way of

saying this that we seek solutions of the form

(x, t) P(z)(1.13)

(x, t) (z)pn N

= =

where z x ct= − .

Here (z)P , (z)N represent density profiles, and c can be interpreted as the

rate of propagation of the colony edge. For these to be biologically

meaningful, we require P and N to be bounded, non negative functions of z.

Then (x, t)p and (x, t)n are a travelling wave, and it moves at a constant

speed c in the positive x - direction if c positive. Clearly if ( x ct− ) is

constant, so are (x, t)p and (x, t)n .It also means the coordinate system moves

with speed c.

7


The wave speed c generally has to be determined. The dependent variable

z is sometimes called the wave variable. When we look for travelling wave

solutions of an equation or system of equations in x and t in the form

(1.13), we have

( c) c

( c) (1.14)

(1)

p dP z dP dPt dz t dz dz

n dN z dN dNct dz t dz dz

n dN z dN dNx dz x dz dz

∂ ∂ = ⋅ = − = − ∂ ∂ ∂ ∂ = ⋅ = − = − ∂ ∂ ∂ ∂ = ⋅ = =∂ ∂

Thus we can reduce the system (1.11) to a set of two ordinary differential

equation:

2 2

1[ ](1.15)

1 [ (1 N) (N P )], 1,1

dP N Pdz cdN P c zdz c

α β

− = − = − − + ≠ −∞ < < ∞−

2-4 Stability of traveling wave solution

The steady state of system (1.15) are (P, N) (0,0)− , and ( , )2 2

α αα β α β+ +

here (0,

0) is stable node and ( , )2 2

α αα β α β+ +

is saddle point for all c positive.

See figure (1.2). This information will help us to determine the initial

condition of MATLAB pplane7 code,

8


Figure (1.2): The (P, N)-plane: note that a trajectories connects the unstable node ( , )

2 2α α

α β α β+ + to the saddle point

(0, 0) for all c positive , 1α = and 1β =

2-5 Numerical solution

To solve this system (1.11), we will using pdepe code in MATLAB. To

show behavior branch and tips, see Fig (1.3) that represented the initial

condition of branch (p) and tips (n),

9


Fig (1.3): The initial condition of (1.13), solution to the system (1.13) with the

parameters 1α = and 1β =

Fig (4) illustrates the traveling waves at the suitable time (t)

Fig (1.4): Solution to the system (1.13) with the parameters 1α = and 1β = ,for time

t=1, 10, 20, …, 200 , where blue line represented tips (n).

10


Fig (1.5) : Solution to the system (1.13) with the parameters 1α = and 1β = , for time

t=1, 10, 20, …, 200 , where red line represented branches (p).

Fig (1.6): Solution to the system (1.13) with the parameters 1α = , 1β = , 0c > and time 1, , 200t = , where blue line represented tips (n), red line represented branches (p). Fig ( 1.4) , (1.5) and (1.6) illustrate the solutions of p and n numerically with take values of 1α β= = , that is very clear the travelling wave solution start from left to right and still the same wave . From this operations we get the relationship between traveling wave solution (c) and parameters α , and β where α increasing the traveling wave solution (c) is increasing, and β increasing the traveling wave solution (c) is decreasing, see Fig.(1.8) and Fig.(1.10) .

11


Fig (1.7): Solution to the system (1.13) with the parameters 5α = , 1β = , 0c > and

time 1, , 200t = , where blue line represented tips (n), red line represented branches

(p).

Fig (1.8): The relation between waves speed c and α values and suppose β is taking

value = 1.

12


Fig (1.9): Solution to the system (1.13) with the parameters 1α = , 5β = , 0c > and

time 1, , 200t = , where blue line represented tips (n), red line represented branches

(p).

Fig (1.10): The relation between waves speed c and β values and suppose α is

taking value = 1.

13


3- Rresults and Discussion

From above results, see Fig.(1.8) and Fig.(1.10) we conclude that the

travilling wave c increase whenever the values of α increase at same

time β is still constant.

So, we know the value of 221

vααγ

= and we notes that α directly

proportional with 2α and v , and inversely proportional with 1γ .

Biologically, that is mean the growth increases whenever α increases, and

finally that means the growth increases according to 2α increasing

(branches produced per unit length hypha per unit time) and v increasing.

From Fig (1.10) we shows that the travelling wave decrease whenever the

value of β increase at same time α is still constant.

So the value of 2 1

2 1

α βββ γ

= and we notes that β directly proportional with 2α

and 1β , and inversely proportional with 1γ and 2β .

Biologically, that is mean the growth decreases whenever β increases.

Finally that means the growth decreases according to 2α increasing

(branches produced per unit length hypha per unit time) , 1β increasing ( 1β

is the rate of tip reconnections per unit time) , 1γ decreasing( 1γ is the loss

rate of hyphal (constant for hyphal death))and 2β decreasing ( 2β is the

rate of tip reconnections per unit length hypha per unit time).

4- References

[1] Murray J.D. 1989. Mathematical Biology II :Spatial Models and biomedical Application. Springer – Verlag New York ,

Inc., 175 Fifth A venue, New York, NY 10010, USA .

14


[2] Edelstein, L. (1982). The propagation of fungal colonies: A model for tissue growth. Journal of theoretical Biology, J

theor.Biol. 98:679-710.

[3] Continuum models for fungal growth, 2011,Ali Hussein Shuaa Al-Taie.

[4] Brian Ingalls.(2012) Mathematical Modelling in Systems Biology.

[5] Schnepf, A. and Roose, T. (2006). Modelling the contribution of arbuscular mycorrhizal fungi to plant nutrient uptake. New

Phytol, 171:669{682.

[6] Peter E. Wellstead, 2005, introduction to physical system modelling .

[7] Michael J. Markowski, 2008, Modeling behavior in vehicular and pedestrian traffic flow.

[8] J.J. Casciari, S.V. Sotirchos, and R.M. Sutherland, Mathematical modelling of microenvironment and growth in EMT6/Ro

multicellularf tumour spheroids, Cell Proliferation, 25 (1992), pp. 1–22.

15


Extract the Artifact signals from EEG-BCI system based on

Blind Source Separation techniques

Dr. Ahmed Kareem Abdullah Dr. Ali Abdul Abbas Abdullah Albakri

AL-Furat AL-Wasat Technical University, Iraq

Abstract

There are numerous challenges in the analysis of EEG-brain signal not solved

radically until now, such as presence of artifact during the recording process, which

makes the analysis of EEG-brain signals very difficult and may be taken as a wanted

signal. In neurophysiological signal analysis, the artifact rejection is an important

research area. Signal separation techniques such as blind source separation (BSS) are

used to overcome the artifact problem by separate the artifacts from EEG mixture as

independent components. The BSS is a method of separating the underlying sources

from their mixtures without or little information about the original sources or the

mixing process. In this paper the BSS techniques are used to extract different types of

artifacts such as power line noise and eye blink artifact from brain, many BSS

techniques are used to compare the results.

باالعتماد على EEG-BSSالضوضاء من نظام أستخالص اشارات

تقنیات الفصل العمیاء

عبدهللا د. علي عبدالعباس عبدهللا البكريد. احمد كریم الملخص

في تحلیل اشاره الدماغ لم تحل لحد االن من ضمنھا استخالص الضوضاء واالشارات الغیر ھناك عده تحدیات

, ھذه االشارات تجعل تحیل اشارات الدماغ صعبھ جدا . ھذا المجال EEGمرغوب بھا من نظام التسجیل في

یعتبر مھم جدا في تحلیل االشارات العصبیھ , وبالخصوص مجال تنظیف اشاره الدماغ , احدى الطرق المھمھ في

مزج او ھذه التقنیھ تستعمل لفصل االشارات بدون معرفھ طریقھ ال, استخالص االشارات ھي تقنیات الفصل العمیاء

16


اشارات االدخال . في ھذا البحث استخدمت عده طرق من تقنیات الفصل العمیاء لتنظیف اشاره الدماغ واستخالص

الضوضاء واي اشاره اخرى غیر مرغوب بھا وطبقت على بیانات حقیقیھ .

1. Introduction

Blind technique was born in the 1980s; the word “blind” is denoting the inversion

or recording method which based on observation only [1]. This technique is used firstly

to design adaptive equalizer for digital communication system. In 1982; the formulation

of source separation was prepared by B. Ans, J. Heranlt, and C. Jutten [2]. The blind

source separation problem was formulated around 1984 [1] using higher-order moments

for matrix approximation and then other similar studies on this field was developed to

describe theoretical fundamentals as in [3]. The fast BSS algorithm was developed for

independent component analysis [4]. Electroencephalography (EEG) is a non-invasive

medical technique used to measure the brain electrical activity, which produced from

joint activity of millions of cortical neurons. These activities are measured by sensors

(electrodes) placed on the human scalp [5]. The amplitude of EEG signal is in order of

microvolts [6]. EEG signal was first measured in humans by Hans Berger in 1924. In

1929 he publishes the first paper to explain the technique for recording the electrical

brain activity from the scalp. The main characteristics of EEG–brain signals are: easily

recorded by electrodes, complex–spatiotemporal signals, very good in temporal

regulation, poor in spatial resolution, and depends on the number of electrodes [7].

However, EEG provides very poor quality signals compared with ECoG signals [8].

Almost the EEG signals are submerged and interference by artifact signals which

contaminate the EEG data. Therefore, the artifact signal is one of the major problems in

brain signal analysis. The main application of the EEG is a diagnosing of neurological

diseases.

2. Electroencephalography (EEG)

EEG recording system consists of electrodes, amplifiers, A/D converter, and a

recording device as shown in figure 1 and figure 2. The electrodes measure the brain

signals from the scalp; the amplification process is necessary to enlarge the amplitude

17


of the measured signals, for more accurate the A/D converter is used to digitize the

measured signals, the recording device such as personal computer and data stores are

used to record the EEG signals [8]. The EEG recorded the potential difference over time

between active and reference electrode. EEG Multi-channel up to 128 or 256 active

electrodes [5, 8]. EEG-electrodes are commonly from silver chloride (AgCl) [9]. Good

contact impedance of Electrode-scalp between 1 kΩ and 10 kΩ [10]. The electrode-

tissue interference is also capacitive, therefore it behaves as a low pass filter LPF. The

electrode impedance based on many parameters such as the interference layer, electrode

surface, and temperature [9] can be reduces the impedance by put EEG gel to make a

good conductive between the skin and each electrode. But some of electrodes made

from titanium and stainless-steel called dry electrodes do not need to use any gel [11].

3. Rhythms of Brain activity

The rhythms of normal brain activity can be categorized into different rhythmic

activity based on the level of consciousness [7] and classified according to their

frequency. Each rhythm is recognized by amplitude, frequency, duration, generated

brain areas, and defined according to distribution over the scalp. The frequencies of

brain signal is classified into six classical brain rhythms known as delta (δ), theta (θ),

alpha (α), mu (µ),beta (β), and gamma (γ) as shown in Figure 2.5. The relevant

characteristics of these signals are detailed below.

Delta Rhythm: This is a slow rhythm (Figure 2.5 (a)) lies within frequency range from

1 to 4 Hz with a relatively large amplitude. The amplitude of delta is variable and

associated in adults in deep sleep state and is unusual in adults in a wake state, therefore

large amount of delta signal in awake adults is abnormal case and is related to

neurological diseases [12]. Delta rhythms are detected in babies and decreases as they

age. It is easy submerged by artifact signals due to the low frequency band particularly

the artifact caused by the muscles of the neck or jaw.

Theta Rhythm: This is a slightly faster rhythm (Figure 2.5 (b)) lie within frequency

range from 4 to 7 Hz. It is variable amplitude and associated with creative, meditation

[13], meditative concentration, cognitive processes such as mental calculation [14],

18


emotional stress and conscious awareness[15] . A small amount of theta rhythm can be

recorded in normal a wake adults but its large in young children, older children, and

adults in drowsy, meditative or sleep states [12]. It is like delta rhythms, a large amount

in wake adults is related to neurological disease.

Alpha Rhythm: Alpha rhythm is an oscillation (Figure 2.5 (c)) lies within frequency

rages from 8 to 12 Hz with high voltage amplitude over the occipital areas [16] and

reflect the visual processing in that region and may also be related to the memory brain

function [17]. This rhythm is appear mainly in the posterior regions of the head

(occipital lobe) when the subject has closed eyes or is in a relaxation state. Its amplitude

is increased when the eyes are closed and the body in relaxes case but they reduced

when the eyes are opened and the mental effort is made [18] or by hearing unfamiliar

sound.

Mu Rhythm: Mu rhythm is found in the 8-13 Hz frequency band about the same alpha

range (Figure 2.5 (d)). It is located in the motor and sensorimotor cortex [19]. The

amplitude of this rhythm varies when the subject performs movements. This rhythm is

also known as the “sensorimotor rhythm” [16].

Beta Rhythm: Beta rhythm is a relatively fast rhythm (Figure 2.5 (e)) lies within

frequency range from 13 to 30 Hz, associated with motor activities, attention, solving

concrete problem, thinking, and focusing and it is recorded over frontal and central

reign. It has symmetrical distribution when there is no motor activity but in active

movement, it is attenuate d and the symmetrical distribution is changed [20].

Gamma Rhythm: Gamma rhythm (Figure 2.5 (f)) lies within frequency range from 30

to 100 Hz; associated with mechanism of consciousness and in normal adult is related to

certain motor functions or perceptions [21]. Gamma rhythms are less used in EEG-

based BCI, because power line noise interferences (50/60 Hz) and artifacts such as

electromyography (EMG) are likely to affect them [22]. But in the BCI based on

gamma activity the information transfer rate is high compared to traditional beta and

alpha signals, offer higher spatial specificity [23]. Table 1 shows the main brain activity

associated with different frequencies.

19


Table 1 Characteristics of Brain signals

Name Symbol Frequency (Hz) Activity Delta δ 1-4 Deep sleep

Theta θ 4-7 Sleep

Alpha α 8-12 Light sleep

Mu µ 8-13 motor

Beta β 13-30 Wakefulness

Gamma γ 25-100 Cognitive processing

4. Stone’s BSS algorithm

Stone’s BSS is based on the temporal predictability measure (TP) to separate the

original sources from their mixture. The conjecture of Stone is: The TP of any signal

mixture is ≤ that of any of its components, this conjecture is used to find the weight

vector which gives an orthogonal projection of mixtures [24]. The BSS model is

depicted in figure 1.

The mixing system without noise is:

𝐱𝐱(𝑘𝑘) = 𝐀𝐀 𝐬𝐬 (𝑘𝑘) (1)

Where

𝐱𝐱(𝑘𝑘) = [𝑥𝑥1(𝑘𝑘), … 𝑥𝑥𝑛𝑛(𝑘𝑘)]T is the mixture vector from sensors ( known ),

s

Sources

s= Wx

Separated

x = As

Measured

A Mixing

A-1= W Separating

Figure 1 Schematic illustration of BSS mathematical model

20


𝐬𝐬(𝑘𝑘) = [𝑠𝑠1(𝑘𝑘), . 𝑠𝑠𝑛𝑛(𝑘𝑘)]T is the source vector ( unknown ),

T is a superscript refers transpose operator,

𝐀𝐀 ∈ 𝑅𝑅𝑛𝑛×𝑛𝑛 is a mixing matrix (unknown),

k is time or sample index.

The goal is to recover s from x without knowing A, to solve this problem the

separating matrix W should be founded which it is W=A-1 in ideal case.

The recovered signals are calculated by the separating model:

𝐲𝐲(𝑘𝑘) = 𝐖𝐖 𝐱𝐱(𝑘𝑘) (2)

Where, y is the permutation of s up to scaling factor.

Stone’s measure of temporal predictability of signal y(k) is defined as [24]:

𝐹𝐹(y) = log 𝑉𝑉𝑦𝑦𝑈𝑈𝑦𝑦

= log∑ (𝐲𝐲long(𝑘𝑘)−𝐲𝐲(𝐤𝐤))Nk=1

2

∑ (𝐲𝐲short(𝑘𝑘)−𝐲𝐲(𝑘𝑘))Nk=1

2 (3)

𝐲𝐲short(𝑘𝑘) = 𝛽𝛽𝑆𝑆 𝐲𝐲short(𝑘𝑘 − 1) + (1 − 𝛽𝛽𝑆𝑆)𝐲𝐲(𝑘𝑘 − 1): 0 ≤ 𝛽𝛽𝑠𝑠 ≤ 1,

(4)

𝐲𝐲long(𝑘𝑘) = 𝛽𝛽𝐿𝐿 𝐲𝐲long(𝑘𝑘 − 1) + (1 − 𝛽𝛽𝐿𝐿)𝐲𝐲(𝑘𝑘 − 1) ∶ 0 ≤ 𝛽𝛽𝐿𝐿 ≤ 1

(5)

Where N is the number of samples of y(k) , 𝛽𝛽𝑠𝑠 = 2−1/ℎshort, 𝛽𝛽𝐿𝐿 = 2−1/ℎ𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿 and hshort,

hLong are the half-life parameters (according to the Stone [24] the half-life hLong of 𝛽𝛽𝐿𝐿 is

100 times longer than corresponding half-life hShort of 𝛽𝛽𝑆𝑆).

Assume 𝐲𝐲(𝑘𝑘) = 𝐰𝐰iTx(k), 𝐰𝐰 = [𝑤𝑤1,𝑤𝑤2, …𝑤𝑤𝑛𝑛], then (4-3) can rewritten as:

𝐹𝐹(yi) = log 𝐰𝐰i𝐂𝐂xxlong𝐰𝐰i

T

𝐰𝐰i𝐂𝐂xxshort𝐰𝐰iT (6)

Where 𝐂𝐂𝐱𝐱𝐱𝐱long is a long-term covariance matrix (𝑁𝑁 × 𝑁𝑁) between signal mixtures;

𝐂𝐂𝐱𝐱𝐱𝐱short is a short-term covariance matrix (𝑁𝑁 × 𝑁𝑁) between signal mixtures. 𝐂𝐂𝒙𝒙𝒊𝒊𝐱𝐱𝒋𝒋long and

𝐂𝐂𝒙𝒙𝒊𝒊𝐱𝐱𝒋𝒋short between ith and jth mixtures defied as:

21


𝐂𝐂𝑥𝑥𝑖𝑖x𝑗𝑗

short = ∑ �𝑥𝑥𝑖𝑖𝑖𝑖 − 𝑥𝑥𝑖𝑖𝑖𝑖𝑠𝑠ℎ𝑜𝑜𝑜𝑜𝑜𝑜��𝑥𝑥𝑗𝑗𝑖𝑖 − 𝑥𝑥𝑗𝑗𝑖𝑖𝑠𝑠ℎ𝑜𝑜𝑜𝑜𝑜𝑜�𝑖𝑖

(7)

𝐂𝐂𝑥𝑥𝑖𝑖x𝑗𝑗long = ∑ (𝑥𝑥𝑖𝑖𝑖𝑖 − 𝑥𝑥𝑖𝑖𝑖𝑖

𝑙𝑙𝑜𝑜𝑛𝑛𝑙𝑙)(𝑥𝑥𝑗𝑗𝑖𝑖 − 𝑥𝑥𝑗𝑗𝑖𝑖𝑙𝑙𝑜𝑜𝑛𝑛𝑙𝑙)𝑖𝑖

(8)

The main aim of Stone’s BSS is to maximize Rayleigh’s quotient to yield

separating vectors; thereby generalized eigenvectors of 𝐂𝐂𝐱𝐱𝐱𝐱long [𝐂𝐂𝐱𝐱𝐱𝐱short ]−1are considered

to solve this problem [24-26]; to find the eigenvectors (w1,w2,w3,…..,wM) of matrix

(𝐂𝐂𝑠𝑠ℎ𝑜𝑜𝑜𝑜𝑜𝑜 −1𝐂𝐂𝑙𝑙𝑜𝑜𝑛𝑛𝑙𝑙) which are orthogonal in the covariance matrices :

𝐰𝐰i𝐂𝐂short 𝐰𝐰jt = 0 (9)

𝐰𝐰i𝐂𝐂long 𝐰𝐰jt = 0

(Error! No text of specified style in document.10)

Where

𝐰𝐰i𝐂𝐂short 𝐰𝐰jt = ∑ �𝑦𝑦𝑖𝑖𝑖𝑖 − 𝑦𝑦𝑖𝑖𝑖𝑖𝑠𝑠ℎ𝑜𝑜𝑜𝑜𝑜𝑜��𝑦𝑦𝑗𝑗𝑖𝑖 − 𝑦𝑦𝑗𝑗𝑖𝑖𝑠𝑠ℎ𝑜𝑜𝑜𝑜𝑜𝑜�𝑖𝑖

𝐰𝐰i𝐂𝐂long 𝐰𝐰jt = ∑ (𝑦𝑦𝑖𝑖𝑖𝑖 − 𝑦𝑦𝑖𝑖𝑖𝑖

𝑙𝑙𝑜𝑜𝑛𝑛𝑙𝑙)(𝑦𝑦𝑗𝑗𝑖𝑖 − 𝑦𝑦𝑗𝑗𝑖𝑖𝑙𝑙𝑜𝑜𝑛𝑛𝑙𝑙) 𝑖𝑖 (11)

When the short-term half-life parameter hshort toward zero value (ℎshort → 0) then the

short-term mean is:

𝑦𝑦τshort ≈ 𝑦𝑦τ−1 (12)

(𝑦𝑦τ − 𝑦𝑦τshort) ≈ dyτ/dτ = 𝑦𝑦τ (13)

Also when the long-term half-life parameter hlong toward the infinity (ℎlong → ∞) and

y has zero mean then the long-term mean is:

𝑦𝑦long ≈ 0 (14)

(𝑦𝑦τ − 𝑦𝑦τlong) ≈ 𝑦𝑦τ (14)

Now under these conditions the expectation value for 𝑦𝑦𝑖𝑖 and 𝑦𝑦𝑗𝑗 are equal to zeros:

22


E�yiyj𝑇𝑇� = 0 (15)

Therefore; this indicate that each recovered signal 𝐲𝐲𝑖𝑖 which can be calculated by 𝐲𝐲𝑖𝑖 = 𝐰𝐰i𝐱𝐱 is uncorrelated with every other signal 𝑦𝑦𝑗𝑗 which also calculated by 𝐲𝐲j = 𝐰𝐰j𝐱𝐱 ; as well as if 𝐲𝐲i and 𝐲𝐲𝑗𝑗 are independent then the expectation value is also zero. This method is powerful for any linear mixture with statistically independent signals and it's guaranteed to separate the independent components. The temporal derivative of each recovered signal is uncorrelated with every one and the expectation value equal zero:

E�yiyj𝑇𝑇� = 0 (167)

Finally the separating matrix w calculated by Matlab eigenvalue function as:

𝐰𝐰 = eig(𝐂𝐂long𝐂𝐂short) (178)

This is one of the advantages of the Stone’s BSS to simplify the BSS problem into

generalized Eigen problem [27].

5. Results Real EEG data are taken from computerized EEG device with a sampling rate 256

Hz. studies are implemented to separate the ocular artifacts without lose any useful information from recording EEG signals as tested in [28] . The ISR measure is not applicable for real EEG data because the mixing process is unknown. Therefore, the correlation measure is used to assess the extraction process for the proposed algorithms. Nine channels are used in this study; where, six electrodes (Fp1, Fp2, C3, C4, O1, and O2) used to measure the brain signals which placed on the scalp according to 10-20 system, one electrode as a ground placed at Cz (figure 3), and two EOG electrodes (vEOG & hEOG) placed above and on the side of the left eye socket to measure EOG activity from eyes and face.

the channels-reference method (EOG channels (vEOG & hEOG)) is used to compare

the results [29]. The recording EEG signals are contaminated by eye blink artifact and

power line noise 50-Hz. The eye blinking artifact is clearly in the frontal channels (Fp1,

Fp2) and decreased in the distance of the electrodes from the eye. All the EEG channels

Figure 3 Placement of electrodes

23


are contaminated by power line noise 50- Hz but strongly different contamination.

Power line noise is pronounced on the central (C3 & C4) and occipital channels (O1 &

O2) [29] as shown in figure 4.

Very good extraction of the line noise interference and eye blink artifact by the

proposed algorithms, where in stone BSS algorithm the power line noise interference is

concentrated and separated in IC1 and the eye blink artifact is clearly isolated in IC6 as

shown in Figure 5.

Figure 4 Data set I with zero mean and unit variance

0 500 1000 1500 2000 2500-5

0

5

Time

Ampl

itude

(FP2)

0 500 1000 1500 2000 2500-4

-2

0

2

4

Time

Ampl

itude

(C3)

0 500 1000 1500 2000 2500-4

-2

0

2

4

Time

Ampl

itude

(C4)

0 500 1000 1500 2000 2500-4

-2

0

2

4

Time

Ampl

itude

(O1)

0 500 1000 1500 2000 2500-4

-2

0

2

4

Time

Ampl

itude (O2)

0 500 1000 1500 2000 2500-5

0

5

Time

Ampl

itude (vEOG)

0 500 1000 1500 2000 2500-5

0

5

Time

Ampl

itude

(hEOG)

0 500 1000 1500 2000 2500-5

0

5

Time

Ampl

itude

(FP1)

Figure 5 Separated components for Data set I by SBSS

0 500 1000 1500 2000 2500-4

-2

0

2

4

Time

Ampl

itude

(IC1)

0 500 1000 1500 2000 2500-5

0

5

Time

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itude

(IC2)

0 500 1000 1500 2000 2500-4

-2

0

2

4

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itude

(IC3)

0 500 1000 1500 2000 2500-4

-2

0

2

4

Time

Ampl

itude

(IC4)

0 500 1000 1500 2000 2500-4

-2

0

2

4

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itude

(IC5)

0 500 1000 1500 2000 2500-5

0

5

10

Time

Ampl

itude

(IC6)

24


In EMBSS algorithm the line noise extracted in IC6 and the eye blink artifact

extracted in IC1 as shown in figure 6.

Table 2 shows the correlation between artifact-reference signal and the extracted

eye blink artifact component. The correlation result illustrates that the ESBSS algorithm

is more powerful than other BSS algorithms to extract the eye blinking artifact. Table

6.18 shows type of separated components based on sparsity value, IC1 is a power line

noise because its value very low (less than 1), and the IC6 is classified as the artifact

signal due to high sparsity value (more than 2.5 based on [30]).

Table 2 Correlation between artifact-reference & extracted eye blinking artifact

BSS

Correlation between artifact-reference & Estimated artifact using Channel-

reference (vEOG)

Stone 0.8677

FICA 0.8594

SOBI 0.8505

JADE 0.7987

Figure 6 Separated components for Data set I by FICA

0 500 1000 1500 2000 2500-2

-1

0

1

2

Time

Ampl

itude

(IC6)

0 500 1000 1500 2000 2500-6

-4

-2

0

2

4

6

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Ampl

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(IC3)

0 500 1000 1500 2000 2500-6

-4

-2

0

2

4

6

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(IC2)

0 500 1000 1500 2000 2500-6

-4

-2

0

2

4

6

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(IC4)

0 500 1000 1500 2000 2500-6

-4

-2

0

2

4

6

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(IC1)

0 500 1000 1500 2000 2500

-5

0

5

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Ampl

itude

(IC5)

25


6. Conclusion

The analyzing of EEG mixture is a new application for Stone’s BSS algorithm,

whereby almost previous works based on independent component analysis which has

some inherent disadvantages. The results obtained by the stone and FICA algorithms

are encouraging to correct the EEG data and can apply them in medical applications as

expected. Real EEG data are taken with different number of channels to measure the

performance of the proposed algorithms.

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[12] A. Kübler, B. Kotchoubey, J. Kaiser, J. R. Wolpaw, and N. Birbaumer, "Brain-Computer Communication: Unlocking the Locked in," ed Washington, DC, USA: American Psychological Association, 2001.

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and lower alpha reflect emotionally positive state and internalized attention: High-resolution EEG investigation of meditation.," Neurosci. Lett. , vol. 310, pp. 57–60, 2001.

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[15] W. Klimesch, M. Doppelmayr, A. Yonelinas, N. E. A. Kroll, M. Lazzara, D. Röhm, et al., "Theta synchronization during episodic retrieval: Neural correlates of conscious awareness. ," Cogn. Brain. Res., vol. 12, pp. 33–38, 2001.

[16] J. A.P., "The functional significance of mu rhythms: Translating “seeing” and “hearing” into “doing”." Brain Res. Rev., vol. 50, pp. 57–68, 2005.

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رمونات : المحفز للدرقیة , الثایرونین ثالثي الیود و الثایروكسین قیاس مستوى ھ لدى مرضى الثالسیمیا نوع بیتا الكبرى في مدینة كركوك

فضیلة سلمان عزیز

الخالصة

تظھر حالة قصور الغدة الدرقیة عادة في العقد الثاني من عمر مرضى الثالسیمیا الكبرى, نتیجة لفرط الحدید. ھذه الدراسة تھدف الى تقییم وظائف الغدة ك ھذه الحالة تحدث أنویعتقد

.الدرقیة لمرضى الثالسیمیا الكبرى

) عاما, وقد اجري لھم احتساب20-10( مریضا بمتوسط عمري مابین 34شملت الدراسة قیاس مستوى كل من ھورمون وظیفة الغدة الدرقیة و قیاس حمل (فرط) الحدید و ذلك من خالل

الى باإلضافةالثایروكسین , ھرمون الثایرونین الثالثي الیود و الھرمون المحفز للغدة الدرقیة قیاس مستوي حدیدین المصل, أجریت الدراسة على عینة من مرضى الثالسیمیا في مركز

ي تشرین الثاني الثالسیمیا / مستشفى أزادي التعلیمي في مدینة كركوك للفترة ما بین شھر 22سیطرة مجموعةك أصحاءاشحاص شملت ھذه الدراسة أیضا. 2016 و كانون األول/

شخصا من ذات الفئة العمریة و الجنس.

جمیع فحوصات الغدة الدرقیة للمرضى كانت ضمن المعدالت الطبیعیة مقارنة بمجموعة و السیطرة, ما عدا ثالث مرضى حیث كان لدیھم زیادة في مستوى الھرمون المحفز للدرقیة

نقصان في كل من ھرمون الثایروكسین و ھرمون الثایرونین ثالثي الیود. مستوى حدیدین نانو غرام/مل) أعلى من مجموعة السیطرة 1721±1927المصل للمرضى كان(

)56,54±11,56(. دلت ھذه الدراسة على إن قصور الغدة الدرقیة ممكن أن یحدث في العقد الثاني من العمر لدى

مرضى الثالسیمیا الكبرى بالرغم من التقدم في العنایة الصحیة للمرضى.

Estimation of TSH, T3 & T4 in beta-thalassemia major patients in Kirkuk city

Fadheelah Salman Azeez

Hawija Technical Institute, pathological analysis Dept.

[email protected] Abstract In the second decade of life, Hypothyroidism usually appears and is thought to be associated with iron overload in patients with thalassemia major. This study aimed to evaluate thyroid functions in patients with beta-thalassemia major.

Thyroid function and iron load status were evaluated in 34 patients with a mean age of (10-20) years with beta-thalassemia major by measuring serum thyroxin (T4), serum triiodothyronine (T3), thyroid-stimulating hormone (TSH) and ferritin levels from serum of patients admitted to

29



thalassemia center at Azadi teaching hospital in Kirkuk city, between November and December 2016. A control group [22] formed from an age-sex matched healthy persons with a mean age of 15±3.66 years was also included.

All parameters of thyroid in patients were within the normal ranges compared with the controls except three of them which had high TSH levels and low T3 and T4. Serum ferritin level (1927±1721 ng/mL) in patients was significantly higher than in controls (56.74±11.56 ng/mL). This work implies that hypothyroidism could be even seen in the second decade of life in patients with beta-thalassemia major in spite of improved hematological cares.

1. Introduction: Beta-thalassemia major is an autosomal recessive hereditary anemia, that is incurable, caused by defective synthesis of hemoglobin, ineffective erythropoiesis and rapid erythrocyte breakdown, lead to advanced heart failure and death in early childhood [1,2] Thalassemia is the most common genetic disorder worldwide [3]. The striking increase in survival of these patients over the past decade has focused attention on abnormal endocrine function, now the most prevalent iron-induced complication in older patients [4]. Chronic blood transfusion therapy results in excessive iron accumulation in different organs which was associated with high early fatalities. With theintroduction the drugs of iron chelators, especially the oral ones during the last decade, rates of survival have improved [5] but endocrine complications became more and more frequent in longterm survivors and substantially affect their quality of life[6]. Transfusion-related iron overload is the primary therapeutic complication in thalassaemia major. Haemosiderosis of different endocrine glands including the thyroid gland has been documented histologically[7], and clinical evidence of decreased endocrine function, particular failure of pubertal development, is often found after the first decade of life[8]. Thyroid dysfunctions are well reported in patients with thalassemia major requiring frequent and recurrent blood transfusions [9-16].

The frequency of hypothyroidism in Thalassemia patients ranges from 6 to 30% among different countries depending on chelation regimens [17]. Lower prevalence was found in patients who had evidence of lower iron load as measured by ferritin levels. The prognosis depends on the amount and the period of iron overload [18 ].

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Primary hypothyroidism that may affect thalassemic patients from the second decade of life is mainly due to gland infiltration by iron overload. Autoimmune thyroiditis is absent [19]. Central hypothyroidism resulted from decreased secretion of thyrotropin stimulating hormone (TSH) from the anterior pituitary gland or by decreased secretion of thyrotropin-releasing hormone (TRH) from the hypothalamus is less common. The thyroid gland appears to fail before the thyroid-pituitary axis, which is less sensitive than the gonadal axis to iron-induced damage [20].

Organ siderosis (liver, cardiac and skeletal muscle, kidney) may affect specific receptors, which regulate thyroid hormone action and convert T4 to the bioactive T3. Recent studies have also demonstrated the incidence of Interferon induced thyroiditis in 40% of Thalassemia patients with Hepatitis C treated with IFN α, which seems to be induced by IFNα via both immune stimulatory and direct toxic effects on the thyroid [21].

A wide spectrum of pathogenic mechanisms is involved. Iron overload and tissue chronic hypoxia have a direct toxic effect on the thyroid gland [22]. High concentrations of labile plasma iron and labile cell iron which are considered responsible in the formation of free radicals and the production of reactive oxygen species (ROS) may lead to cell and organ damage[23].

The present study aims to assess thyroid function in patients of β-thalassemia major and to evaluate its relation, if any, with serum ferritin levels.

2. Patients and Methods:

Clinical information collected from 34 patients with β-thalassemia major who attended Azadi – teaching Hospital in Kirkuk city during the period from November until December 2016, and filled the questionnaires. The patients aged between 10 – 20 years (mean: 15.1 ± 4.8 years), and all were residents of Kirkuk city. All patients were homozygous for beta-thalassemia and were being treated with frequent transfusions to maintain the post transfusion hemoglobin level above 10g/dL, and long-term iron chelation therapy with desferoxamine (DFX) had been started in patients over 2.5-year-old, with serum ferritin concentrations over than 1000 µg/L. The dose of DFX had been 30 – 50 mg/kg/day subcutaneously, 5 – 6 nights a week.

Twenty two age and sex matched patients without thalassemia constituted the control group. Blood was aspirated from all of the subjects in the early morning (8–10 AM) and separated into two aliquots, with one sample being stored in anticoagulated tubes for

31


hematological estimations and the other in plain tubes for estimation of the other parameters in sera. Comparison was made between case and control for serum ferritin and thyroid profile. TOSOH bioscience - AIA 360 Auto analyzer With TOSOH bioscience T3, T4, TSH Kits were used for our purpose [24,25]. Serum Ferritin was measured by an enzyme linked assay method using a kit supplied by Biomerieux (France) by VIDAS technique [26] .

3. Resulst:

None of the patients have had goiter , the result of physical examination showed. A total of 34 patients were enrolled in the study, 14 (41.17 %) of them were female and 20 (58.82 %) male. Mean hemoglobin (Hb) levels before and after transfusion of blood were reported as 8.7±0.6 and 12.8±1.2. This value was 13.3±1.4 in the control group. Biochemical parameters measured in serum of patients and healthy group are recorded in Table 1. Table 1: Parameters for patients with beta-thalassemia and controls.

Parameters Controls(n=22) Patients(n=34) Normal range

Signif-icance

Means(SD) range Means(SD) range

Age (year) 15.3 ± 3.8 10-20 15.1 ± 4.8 10-20 NS

T3 (ng/mL) 1.183±0.293 0.734-1.774 1.509±0.461 0.323-2.411 0.69-2.15 S

T4 (ng/mL) 89.59±15.62 49.288-101.344 97.910±16.936 45.588-127.12 52-127 NS

TSH (uIU/mL)

2.844±1.104 0.824-4.896 3.251±2.076 1.407-11.017 0.3-4.5 NS

S. Ferritin (ng/mL)

56.74±11.56 39.2-66.19 1927±1721 207-9658 7-150 High S

T3: total thyroxin , T4: total triiodothyronine , TSH: Thyroid-stimulating hormone, S. ferritin :serum ferritin

The levels of TSH were higher than normal range only in three patients. Low TSH levels were not detected. The total T3, T4 levels were normal in these 3 patients except in two (have low T3) and one patient has low T4.

All three patients were classified as subclinical primer hypothyroidism, except these three cases, we had not found any

32


significant increase (p˃0.05) in TSH level of patients than that of controls.

In regard of T3 & T4 levels: our study revealed a significant increase (p˂0.05) in the level of the T3 hormone in patients serum as compared with the hormones level in controls, also that no significant difference in regard of T4 of both patients & healthy group, although both results (T3& T4)of the two groups(patients & controls)were within the normal range. It was observed that transfusion frequency had a significant increasing effect on the serum ferritin level (P<0.001) .

Splenectomy was applied to some patients, but we didn't notice any significant (p˃0.05) difference in regard of the levels of TSH , T3 and T4 between the splenectomized & non splenectomized patients.

It was found that the use of DFO had no statistically significant effect (P>0.05) on the biochemical parameters.

The correlation between parameters studied was as follows. A week positive correlation between serum ferritin & TSH(r=0.2257), between S. ferritin & T3(r=0.0012), between s.ferritin & T4 (r=0.1261).

S.ferritin & TSH S. ferritin & T3

S. ferritin & T4

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4. Discussion:

The present study showed that T3, T4 levels in all patients (except two who have decreased T3 and one has low T4) were in normal range compared with those in controls while TSH level was found to be high in only 3 patients (all of these three patients have very high level of serum ferritin )and normal in the remaining 31 patients. However, mean ferritin level were significantly higher in patients compared to those of controls (Table 1).

The three patients with high TSH might be classified as subclinical primer hypothyroidism. Other manifestations of hypothyroidism such as overt primary hypothyroidism and secondary hypothyroidism were not found in the presented patients. In a recent paper, De Sanctis et al[6] and Malik et al[27] reported the ratio of primary hypothyroidism as 2.1% (in a study group of 238 patients aged 2-17 years) and as 25.7% (in a study group of 70 patients aged 5-14 years) with TM. In our study, this was 8.82% . The reason for the lower frequency may be attributed to the fact that the majority of patients in the present work were committed with transfusion monthly and with chelating treatment.

After approximately one year of transfusions, iron starts to be accumulated in parenchymal tissues, where it may bring about substantial toxicity as compared with that within reticuloendothelial cells[28,29]. Despite the reports relating endocrine dysfunction with iron overload it was recently demonstrated that the degree of iron overload, at least reflected by ferritin levels, was not associated with the development of endocrine complications [30,31].

Our study also showed that there is a weak positive correlation between serum ferritin level and thyroid function but a strong positive correlation between transfusion frequencies, an indirect indication of ferritin overload, and hypothyroidism, Abdulzahra et. al. (32) (Najaf city)study result was in accordance with ours.

The absence of the relationship between ferritin and hypothyroidism may be explained by suggesting that the damage of endocrine glands caused by chronic hypoxia is more pronounced than that caused by hemosiderosis as a consequence of the collapse of iron. Although the use of iron chelation therapy has been known to delay or reverse the development of iron-induced cardiac damage and to improve survival[33], the ability of deferoxamine (DFO) to prevent iron-induced endocrine complications is less well defined, but with increased survival, the consequences of endocrine failure become more important. In our study, three patients assigned as subclinical primary hypothyroidism were approximately 13 years old and they were not

34


receiving regular DFO treatment. The study also showed that DFO has no effect on any parameter studied.

It was shown that splenectomised patients (n=5) were older (17.6±4.1) than those (13.3±3.51) not-splenectomised (P<0.001). The result also indicated that splenectomy has no effect on thyroid function, which is consistent with previous studies [34,35].

Table 2: Showed the prevalence of hypothyroidism in different of world compared with our data [36].

country No of patients Prevalence of Hypothyroidism%

Iran 56 16 Jordan 36 0

Indonesia 179 26.8 Greece 200 16.5 Oman 30 3.3

Turkey 90 3.3 90 3.3 Qatar 48 35

Thailand 51 17.6 Italy 97 21.6

Pakistan 70 25.71 Baghdad 73 21.9 Kirkuk 34 8.82

5. Conclusion:

Thyroid function should be followed periodically, particularly when other iron overload-associated complications occur that because thyroid dysfunction in thalassemia major may start early in life though with a low frequency. Therefore, early recognition and hence prevention of these complications might help improve the quality of life of these patients. References:

[1] Weatherall DJ, Clegg JB. (Inherited haemoglobin disorders: an increasing global health problem). Bull World Health Organ 2001;79(8):704-12. [2] Weatherall DJ, Clegg JB, editors. (The Thalassemia Syndromes). 4th ed. Oxford: Blackwell Science. 2001; Pp: 121-392. [3] Rund D, Rachmilewitz E. (Beta–thalassemia). (New Engl J Med). 2005; 353: 1135-46. [4] Olivieri NF. (The beta thalassemias). (New Engl J Med). 1999; 341: 99-109. [5] Telfer PT, Warburton F, Christou S, Hadjigavriel M, Sitarou M, Kolnagou A. (Improved survival in thalassemia major patients on switching, from desferrioxamine to combined chelation therapy

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with desferrioxamine and deferiprone). (Haematologica), (2009). Vol. 94(12), pp. 1777-8. [6] De Sanctis V, Roos M, Gasser T, Fortini M, Raiola G, Galati MC; Italian Working Group on Endocrine Complications in Non-Endocrine Diseases. (Impact of long-term iron chelation therapy on growth and endocrine functions in thalassaemia). (J Pediatr Endocrinol Metab), (2006); Vol.19, pp. 471-80. [7] Zaino E C. (Pathophysiology of thalassaemia). Ann NY Acad Sci 1980; 344: 284-304. 8- Modell B. (Total management of thalassaemia major). Arch Dis Child-1977; 52: 489-500. [9] Srivatsa A, Arivatsa A. (Assessment of adrenal endocrine function in Asian thalassemics). (Indian Pediatr )2005;42(1):31–5. [10] Al-Elq AH, Al-Saeed HH. (Endocrinopathies in patients with thalassemias). (Saudi Med J ) 2004; 25(10):1347–51. [11] Karamifar H, Shahriari M, Sadjadian N. (Prevalence of endocrine complications in betathalassemia major in the Islamic Republic of Iran). (East Mediterr Health J) 2003;9(1-2):55- 60. [12] Zervas A, Katopodi A, Protonotariou A, et al. (Assessment of thyroid function in two hundred patients with beta-thalassemia major). Thyroid 2002;12(2):151-4. [13] Aydinok Y, Darcan S, Polat A, et al. (Endocrine complications in patients with beta-thalassemia major). (J Trop Pediatr) 2002;48(1): 50-4. [14] Baba K, Zantout MS, Azar ST. (Endocrinologic Diseases in hemoglobinopathies). Endocrinologist 2009;19(1):44-7.

[15] Mahraver A, Azarkeivan A, Faranoush M, et al. (Endcrinopathies in patients with transfusiondepentent beta-thalassemia) . Pediatr Hemat Oncol 2008;25(3):187-94. [16] Malik S, Syed S, Ahmed N. (Complications in transfusion-dependent patients with betathalassemia major): (a review. Pak J Med Sci) 2009;25(4):678-82. [17] De Sanctis V, Eleftheriou A, Malaventura C. (Prevalence of endocrine complications and short stature in patients with thalassaemia major): a multicenter study by the Thalassaemia International Federation (TIF). Pediatr Endocrinol Rev, (2004) Suppl 2, pp. 249-55. [18] Borgna-Pignatti C, Rugolotto S, De Stefano P, Zhao H, Cappellini MD, Del Vecchio GC. (Survival and complications in patients with

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thalassemia major treated with transfusion and deferoxamine). Haematologica, (2004) Vol. 89(10), pp. 1187-93. [19] Delvecchio, M.; Cavallo, L. (Growth and endocrine function in thalassemia major in childhood and adolescence).( J. Endocrinol. Invest), (2010) Vol.33, pp. 61-68. [20] Landau H, Matoth I, Landau-Cordova Z, Goldfarb A, Rachmilewitz EA, Glaser B.. (Cross-sectional and longitudinal study of the pituitary-thyroid axis in patients with thalassaemia major), Clin Endocrinol (Oxf), (1993) Vol.38(1), pp. 55-61. [21] Menconi F, Hasham A, Tomer Y. (Environmental triggers of thyroiditis: Hepatitis C and interferon-α) , (J Endocrinol Invest), (2011), Vol.34(1), pp. 78-84. [22] Magro S, Puzzonia P, Consarino C, Galati MC, Morgione S, Porcelli D, Grimaldi S, Tancrè D, Arcuri V, De Santis V. (Hypothyroidism in patients with thalassemia syndromes). Acta Haematol, (1990) Vol. 84, pp. 72-6. [23] Esposito BP, Breuer W, Sirankapracha P, Pootrakul P, Hershko C, Cabantchik ZI.. (Labile plasma iron in iron overload: redox activity and susceptibility to chelation). Blood, (2003) Vol.102(7), pp.2670-7. [24] Robert K. Murray, Daryl K. Granner, Victor W. Rodwell. (Harper’s illustrated Biochemistry), 27th Edition 453-456. [25] Rafi, Text Book of Biochemistry for Medical students, 2nd Edition 703-707. [26] Koivunen, M. E. & Krogsrud, R. L(Principles of immunochemical techniques used in clinical laboratories), Lab Medicine, . (2006) ; 37: 490–497. [27] Malik SA, Syed S, Ahmed N. (Frequency of hypothyroidism in patients of beta-thalassemia). Pak I Med Assoc 2010;60(1):17-29. [28] Hershko C. (Role of iron chelation therapy in Thalassemia major). (Turk JHaematol) 2002; 19(2):121-6. [29] Hoffbrand AV, Cohen A, Hershko C. (Role of deferiprone in chelation therapy for transfusional iron overload). Blood 2003; 102(1):17-24.

[30] Cario H, Holl RW, Debatin KM, Kohne E. (Insulin sensitivity and beta-cell secretion in thalassemia major with secondary haemochromatosis: assessment by oral glucose tolerance test). (Eur J Pediatr )2003;162(3):139- 46. [31] Angelopoulos NG, Goula A, Rombopoulos G, et al. (Hypoparathyroidism in transfusiondependent patients with beta-thalassemia) . (J Bone Miner Metabol) 2006;24(2):87–93. [32] Abdulzahra M., Al-Hakeim H., Ridha M. (Study of the effect of iron overload on the function of endocrine glands in male

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thalassemia patients) . (Asian J Transfus Sci). 2011 Jul-Dec; 5(2): 127–131.

[33] Miskin H, Yaniv I, Berant M, et al. (Reversal of cardiac complications in thalassemia major by long-term intermittent daily intensive iron chelation).( Eur J Haematol) 2003;70(6):398-403.

[34]Aruratanasirikul S, Wongcharnchailert M, Laosombat V, et al. (Thyroid function in β- thalassemic children receiving hypertransfusions with suboptimal iron-chelating therapy) . (JMed Assoc Thai )2007;90(9):1798-802. [35] AG Pirinççioğlu, et al (Thyroid Function in with β-thalassaemia Major). (Iran J Pediatr) ; March 2011, Vol 21 (No 1); Mar 2011, Pp77-82. [36] Najla A , Khaleed J., Ihsan I M. (Hypothyroidism in transfusion dependent β-thalassemia). (Iraqi Journal of Cancer and Medical Genetics). Vol 9 ( No 1) ; 2016 , Pp 36-40.

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https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3159240/

First International Scientific Conference 29 – 30 April 2017 2017نیسان 30 – 29المؤتمر العلمي الدولي األول / ISSN: Issue two / Al-Kut University College 7419 - 2414 الثاني العدد/ كلیة الكوت الجامعة

Assessment the knowledge of patients with Heart Failure in Wasit

تقییم معارف المرضى المصابین بعجز القلب في واسط

Ihsan H Zainel Dean of the High Health Institute in Wasit / Ministry of Health,

[email protected]

الخالصة : خلفیة البحث و ھدف الدراسة:

عج��ز القل��ب ھ��و س��بب رئیس��ي لمع��دل المرض��یة والوفی��ات ف��ي البل��دان المتقدم��ة والنامی��ة والس��بب الرئیسي لدخول المرضى المسنین الى المستشفى . لذلك تقی�یم مع�ارف المرض�ى ال�ذین یع�انون م�ن

.تقلیل مضاعفات المرضعجز القلب مھم جدا من أجل الھدف العام:

تقییم معارف المرضى المصابین بعجز القلب في واسط الھدف الخاص: . لتقییم معارف المرضى الذین یعانون من عجز القلب.1. التعرف الى وجود عالقة بین معارف المرضى المصابین بعجز القلب وخصائصھم االجتماعیة 2

مس��توى ,الحال��ة االجتماعی��ة ,مؤش��ر كتل��ة الجس��م ,المھن��ة ,الج��نس ,والدیموغرافی��ة مث��ل (العم��ر والتدخین ). ,التعلیم

طریقة البحث : ومستش�فى الكرام�ة تم إجراء دراسة وص�فیة ف�ي ردھ�ات الباطنی�ة ف�ي مستش�فى الزھ�راء التعلیم�ي

ن�ة . ش�ملت عی2017ش�باط 28إلى 2016كانون االول 10واسط للفترة من في مدینةالتعلیمي ) مریض مصاب بعجز القلب االحتقاني الذین تم ادخلھم إلى ردھات الباطنی�ة ف�ي 200الدراسة (

مستشفى الزھراء ومستشفى الكرامة التعلیم�ي ال�ذین ت�م اختی�ارھم بش�كل عم�دي. وق�د أع�د الباح�ث استمارة استبیانیھ خاصة لغرض الدراسة ، وتألف االستبیان من جزئیین:

لمتعلق بالمعلومات االجتماعیة والدیموغرافیة للمرضى المصابین بعجز القلب .الجزء األول: ا الجزء الثاني: یتعلق بتقییم معارف المرضى المصابین بعجز القلب .

وقد استخدم الباحث تحلیل البیانات اإلحصاء الوصفي (التكرارات والنسب المئویة و الوزن المرجح الحسابي واالنحراف المعیاري). والوسط النتائج: أظھ��رت نت��ائج الدراس��ة ب��ان المرض��ى المص��ابین بعج��ز القل��ب ل��دیھم مع��ارف جی��دة فیم��ا یتعل��ق

بمرضھم .وال توجد فروق ذات داللة معنویة ب�ین مع�ارف الكلی�ة للمرض�ى المص�ابین بعج�ز القل�ب رافیة للمرضى. كم�ا وج�د ف�رق معن�وي طفی�ف فیما یتعلق ببعض الخصائص االجتماعیة والدیموغ

فیما یتعلق بمتغیرات الدراسة. في جمیع مجاالت معارف المرضى المصابین بعجز القلب االستنتاج:

خلصت الدراسة إلى أن غالبیة المرضى الذین یعانون من عجز القلب یعانون من الس�منة المفرط�ة الس��منة .وكم��ا ان المرض�ى المص��ابین بعج��ز القل��ب وثل�ث الع��دد الكل��ي ھ�م م��ن الدرج��ة الثالث��ة م�ن

لدیھم معارف جیدة بشأن مرضھم . وایضا وجود ف�رق معن�وي طفی�ف ف�ي جمی�ع مج�االت مع�ارف المرضى المصابین بعجز القلب فیما یتعلق بمتغیرات الدراسة.

39



التوصیات:المرضى من أجل تطبی�ق ووفقا لھذه النتائج أوصت الدراسة بنشر كتیبات وتعلیمات وتوزیعھا على

تعلیمات المرض حول السیطرة عل�ى التغذی�ة وتقیی�د الس�وائل والتم�ارین الریاض�یة والس�یطرة عل�ى وزن الجس��م، وینبغ��ي للممرض��ین ومق��دمي الرعای��ة الص��حیة القی��ام ب��دورھم ف��ي تثقی��ف المرض��ى

ئیة للح�د م�ن خط�ر المصابین بعجز القلب وأسرھم لفھم وتطبیق الرعایة الخاصة واتخاذ تدابیر وقا .المرض

Abstract: Background and objective of the study : Heart failure (HF) is a major cause of morbidity and mortality in developed and developing countries and the leading cause of hospitalization in elderly patients. So assessment the knowledge of patients with heart failure (HF) is very important in order to minimize the complications of disease. General Objective Assessing the knowledge of patients with heart failure (HF). Specific Objectives 1. To assess knowledge of patients who are suffering from heart failure . 2. Identifying the relationship between the patients ' knowledge who suffering from heart failure and their socio- demographic characteristics such as (Age, Sex, Occupation, BMI, Marital status, Educational level, and smoking). Methodology: A descriptive study was carried out in medical wards in Al-Zahra Teaching Hospital and Al-Karama Teaching Hospital in Wasit city for the period from 10 December 2016 to 28 February 2017. The sample of the study included (200) patients with CHF who were admitted to the medical wards in Al-Zahra Teaching Hospital and Al-Karama Teaching Hospital chosen purposively. A special questionnaire was prepared by the researcher for the purpose of the study , the questionnaire consists of two parts: Part 1: Related to socio-demographic data of the patients with heart failure. Part 2: Related to assessment the knowledge of patients with heart failure . The analysis of the data was used descriptive statistics (frequencies, percentages, weighted and the arithmetic mean and standard deviation) . Results : The results of the study showed that the Patients with HF had good knowledge concerning their disease . No significant differences were

40


found between the total knowledge of patients with HF regarding some socio-demographic characteristics of the patients. Slightly significant difference was found in the all areas of patients’ knowledge about HF regarding the variables of the study. Conclusion: The study concluded that the majority of patients with HF were obese and about 3rd of them with obesity grade 3. Patients with HF had good knowledge concerning their disease. Slightly significant difference was found in the all areas of patient’s knowledge about HF regarding the variables of the study. Recommendation: According to these results the study recommended publishing pamphlets and instructions and distributed them to the patients in order to apply the illness instructions about nutrition controlling, fluid restriction, exercises and control body weight, and nurses and health providers should take their role in educating the patients with HF and their families to understand and apply special care and take protective measures to minimize the risk of the disease. _______________________________________________________ Keywords: Assessment; Knowledge; Attitudes; Heart Failure .

Introduction: Heart failure (HF) is a major cause of morbidity and mortality in developed and developing countries and the leading cause of hospitalization in elderly patients. More than (50%) of sudden deaths occur by incidence with HF . HF is a major and growing public health problem in the United States; approximately 5 million patients are diagnosed with HF for the first time each year. HF is primarily a condition of the elderly, HF is a critical state which requires an efficient care {22 , 9, 29}. The term heart failure (HF) does not mean that the heart has stopped working , but that its ability to pump blood is weaker than normal in people who have HF the heart cannot pump enough blood to meet the body's need {6, 22, 35}.lives and how to adapt treatment strategies. HF is the inability of the heart to meet the demands of the body. Pump failure may be caused by cardiac abnormalities or conditions that place increased demands on the heart such as cardiac muscle disorders, valvalar defects, hypertension, coronary atherosclerosis, hyperthyroidism, obesity and circulatory overload {32, 14, 23}. When one side of the heart fails there is essentially abuild up of pressure in the vascular system feeding into that side , signs of the right

41


ventricular failure will be evident in the systemic circulation , those of left ventricular failure in the pulmonary system can be divided into Left ventricular HF and Right ventricular HF {13, 27, 36 }. In the other hand , excessive dietary intake of sodium can worsen symptoms, so that patients need to be made aware of such simple dietary precautions as avoiding prepared foods which are generally loaded with salt. Adequate nutrition is also important in minimizing the effects of the skeletal muscle myopathy {14 , 37, 1}. Assessment of life style behaviors, such as smoking, diet, and exercise, nicotine, alcohol drugs have detrimental effect on the heart and blood vessels. Assessment includes asking the client about the frequency and the amount of use for each of these substances and also gathering a diet history .Identify food preferences, snack and methods of food preparation {18,5}. The purpose of management strategies and programs are to use an integrated approach to care through systemic assessment and management, counselling and education of patients, promotion of patient compliance with the treatment regimen, facilitation of hospital discharge and implementation of outpatient models of health care delivery {24, 25, 15}. Adequate knowledge and understanding could play an essential role in improving nutritional status and delaying disease progression in HF .It was estimated that 40% of the reasons for readmission of people with HF were due to diet and medication non-adherence. By educating patients and their families about the importance of diet and nutrition specific to HF, disease symptoms and readmission rates could decrease {8 , 12, 17}.In the other hand , the patients with HF must have sufficient knowledge and positive attitudes about their diseases in order to minimize complications. Cardiac problems are highly relevant to nurses' knowledge , as a nurse is not only concerned with survival of patients with HF and decreased morbidity and mortality . The specialist nurse plays an important role in educating and counseling patients with HF. The vital role of specialist nurse includes, observation and assessment of the patient's condition regarding abnormal or fluctuating vital signs . Weight changes, edema, respiratory changes, medication compliance and dietary habits.Outcomes of care include an achievement of optimal health for the HF patient{31, 30, 33, 4 , 34, 6}.

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Methodology A descriptive design study was carried out during the period from 10 December 2016 to 28 February 2017. The sample of the study consists of (200) patients chosen purposively who were admitted to the medical ward in in Al-Zahra Teaching Hospital and Al-Karama Teaching Hospital .The selection of present sample based on special criteria which include; (1). All patients with HF( (2).Patients who were admitted to medical wards in in Al-Zahra Teaching Hospital and Al-Karama Teaching Hospital during the period of study.(3). Patients Age between 30-80 Years. In order to assess the knowledge of the patients with HF, a special questionnaire was prepared by the researcher consisted of two parts: 1-Part one: includes the socio-demographics characteristic of patients with H.F and body mass index (BMI). 2-Part two: includes information related to the assessment of patients knowledge about HF, the knowledge assessment consists of four main areas:- a-Area of signs and symptoms of HF patients (20 sub items). b-Area of food and fluid of HF patients (15 sub items) c-Area of activity and exercise of patients with HF (5 sub items) d-Area of medication to HF patients (5 sub items) Each sub item had two options: Yes=1and No=0. The following steps were used: 1-Socio-demographic characteristics of patients which include (age, gender(sex) , marital status, educational level and living nature, occupation, smoking ). 2-Body Mass Index (BMI) which includes measuring the weight and height of the patients. 3-Assessment of the knowledge and attitudes of patients with HF. The data were collected by the interviewer himself who explained to the patients the purpose of the study and asked them to answer the questionnaire voluntarily for patients who do not read and write, the researcher explained the nature of questions and filled their answers by himself. While the educated patients filled the questionnaire by themselves. The average time to fill each questionnaire by each patient with assistance and explanation was from 15-30 minutes. The data of present study were analyzed through the application of two statistical approaches .A descriptive statistical approach that includes frequency, percentage, x� ∓ S. D.=Arithmetic Mean (x�) and Std. Dev. (S.D.).,,and an Inferential statistical approach that includes t. test ,

43


ANOVA , BMI . Results were determined as highly significant at (P<0.01)significant at (P<0.05) and non-significant at (P>0.05).

BMI = Table (1) Sociodemographic characteristics of the patients with HF

Table (1) shows that the majority of patients with HF (73%) were from the age group from (61-70 years).About the gender of patients, the rate tends to be equal. The male patients represent 51% and the females

% No. Items Characteristics 3 6 30-40 Age groups ( years )

11 22 41-50 26.5 53 51-60 36.5 73 61-70 23 46 71-80 51 102 Male Gender (sex ) 49 98 Female

84.5 169 Married Marital Status

14 28 Widower 1.5 3 Divorced 42 84 Without work Occupation

48.5 97 House wife 3 6 Civil work

6.5 13 Free job

91.5 183 Primary or less Educational

3 6 Intermediate 1 2 Secondary

4.5 9 Institute or college

30.5 61 Rural Nature of living 69.5 139 Urban 53 106 Smoking

Smoking 47 94 No smoking

44


represent 49% .The majority of patients (84.5%) were married. With regard to occupation , a high percentage of patients were housewives and without work which constitute 48.5 % and 42%, respectively.The majority of the patients (91.5%) were with primary school education and less. Concerning the nature of living, a high percentage (69.5%) of the patients lived in urban (city). Finally, with regard to smoking, more than half of patients ((53%) were smokers .

Table (2) Assessing BMI of patients with HF

% NO. BMI

- - Less than 20(underweight)

29 58 20-25 (normal)

27 54 26-30 (obesity G 1)

26 52 31-35 (obesity G2 )

18 36 More Than 36 (obesity G3)

100 200 Total

Table (2) shows, that the majority of the patients treated with HF (71%) were suffering from obesity and (18%) of them suffered from obesity G 3. Table (3) Comparison between gender scores regarding their total general knowledge

p-value < 0.05 t-value SD X Gender N s

0.42

3.19 30.03 Male 3.13 30.02 Female

df = 199 t-critical = 1.9

Table (3) shows that no significant difference between the patient's gender scores regarding their total general knowledge (t= 0.42)

45


Table (4) Comparison between gender scores of patients with HF regarding their all areas of knowledge

p-value t-value Female Male Gender

Knowledge SD X SD X

0.01 - 3.3 2.1 15.52 2.2 14.45 Signs and symptoms

0.05 2.16 2.5 10.04 2 10.68 Nutrition

0.01 5.7 0.3 0.07 1.03 0.70 Activities and exercises

0.05 -2.32 0.5 4.38 0.6 4.19 Drugs

df = 199 t-critical = 1.9

Table (4) shows, that a highly significant differences at P < 0.01 level between the gender of patients with HF in the area of knowledge in signs and symptoms and activities and exercises. While there are significant differences at (P < 0.05) in the patients gender in the area of nutrition and drugs.

Table (5) ANOVA test for the differences between all areas of patients knowledge regarding their age groups

p-value F-value Age

knowledge

0.05 3.60 Signs and symptoms

NS 0.79 Nutrition

0.05 5.88 Activities and exercise

NS 0.828 Drugs

F. critical = 3.3

Table (5) shows significant differences at (P< 0.05) level between the patient's knowledge in the areas of signs and symptoms, activities and exercises (F=3.60 and 5.88, respectively), while no significant

46


differences found in the areas of nutrition and drugs (F=0.79 and 0.828, respectively).

Table (6) ANOVA test for the difference between all areas of patients knowledge regarding their educational level

p-value F-value

Educational level

knowledge

NS 2.7 Signs and symptoms

NS 0.26 Nutrition

0.01 10.09 Activities and exercise

NS 1.074 Drugs

F. critical = 3.7

Table (6) shows only significant difference at (P< 0.01) level between the patients knowledge in the area of activities and exercises with regard to their level of educational (F=10.09), while the rest show no significant differences with regard to the patient's level of education and knowledge. Table (7) ANOVA test for the difference between all areas of patients

knowledge regarding their marital status.

p-value F-value Marital status

knowledge

NS 0.876 Signs and symptoms

NS 1.902 Nutrition

NS 2.261 Activities and exercise

NS 3.5 Drugs

F. critical = 4.6

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Table (7) shows no significant differences between the patients knowledge in all areas (signs and symptoms, nutrition, activities and exercises and drugs) and their marital status (F=0.876; 1.902; 2.261; and 3.5, respectively).

Table (8) ANOVA test for the difference between all areas of knowledge of patients regarding their occupation

p-value F-value Occupation

knowledge

0.05 4.80 Signs and symptoms

NS 1.5 Nutrition

0.001 17.9 Activities and exercises

NS 2.1 Drugs

F. critical = 3.7

Table (8) shows highly significant differences at (P< 0.001) in the area of activities and exercises and the patient's occupation (F=17.9), also significant differences were found at (P< 0.05) in the area of signs and symptoms and their occupation (F=4.8), while the table shows no significant difference in the areas of nutrition and drugs with regard the patient's occupation (F=1.5 and 2.1 ,respectively).

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Discussion: HF is a chronic, progressive disease that is characterized by frequent hospital admissions and ultimately high mortality rates. Because of its high medical resources consumption, HF is the most costly cardiovascular illness. Advances in the treatment of HF and early intervention to prevent decomposition may delay disease progression and improve survival. After initial evaluation, further diagnostic testing, and implementation of standard medical therapy, out patient management strategies focus on maintenance of patient stability {15}. Patient counseling/education of compliance and discharge planning may further contribute to clinical stability and improved patient outcomes. Our study, the results in table (1) show that the majority of HF patients (73%) were from the age group (61-70 years).This is in agreement with those of Marshall et al {26, 11, 20}.HF is a major public health problem affecting 10% of people older than 75 and accounting for more medicare expenditures than any other diagnosis. Each year HF is responsible for 6.5 million in hospital days and 13 million outpatient visits in persons older than 65, It is associated with 20% of all hospital admission {16}. The explanation for this can be attributed to the fact that HF is usually a gradual process that needs many years to develop. Regarding the gender of patients, the rate tends to be equal which the male patient’s represent 51% and the females represent 49%.The result is goes with those of AL-Baddranii{ 2 }which showed no significant association between age, gender and HF . While it is in contrast with those of Graham et al{16 } who mentioned that patients with HF are typically more prevalent in elderly, female, diabetic, and hypertensive. This result can be explained through the presence of multiple physiological and psychological sex variation in addition to the work stress, certain habits such as smoking and alcoholism and the higher liability for acquiring hypertension for males than females that may be one cause of HF. Majority of patient’s (84.5%) were married .With regard to occupation a high percentages of patients were housewives and without work which constitute 48.5% and 42% respectively. Majority of patients (91.5%) were with primary school education and less. Effective education of patients and their relatives about the causes and treatment of HF can help to adherence in management plan {19}. Concerning the nature of living, a high percentage (69%) of the patients lived in urban (city).It is clear that there is high incidence with HF in the urban area than rural area. This may be due to difficult of living in city, stress, and

49


psychological problems. Finally more than half of patients (53%) were smokers. This is in agreement with Coats{7}. Smoking is a strong risk factor for heart disease and sudden coronary death, even in light cigarette. Moreover, smoking potentates other risk factors such as lipid abnormalities and hypertension {21}. Information related to the body mass index (BMI) , results of the study in table(2) indicate that the majority of the patients with HF (71%) were suffering from obesity, (18%) of them suffered from obesity G3 .This is in agreement with those of Marshall et al{26}.Only (29%) of the patients were within the normal range (20-25). To increase muscle mass and strength in patients with chronic HF, there is a need for implementing resistance exercises in exercise training programs due to muscle wasting and reduced peak oxygen consumption of chronic HF as well as negative prognostic factors. Impaired muscular strength in HF compared with normal has been demonstrated to be due to a smaller muscle cross-sectional area{28}. Several studies have evaluated body mass index (the weight in kilograms divided by the square of the height in meters)as a risk factor for left ventricular remoding and over HF. In these investigations, obesity has been consistently associated with left ventricular hypertrophy and dilatation, which are known precursors of HF. Whereas extreme obesity has been associated with HF {21}.

Results of the study revealed that there were no significant differences between the patient’s genders regarding total knowledge of patient, (tables 3).The results is in agreement of those of Galiff and Oconnor {10}. These results indicate that both males and females had the same burdens due to the nature of disease, its signs and symptoms which had the same level of effect on both genders, so that the both were be aware to know information and tried to follow and applied the instructions of the health team in order to minimize the complications of the disease. While the result of table(4) indicates a significant differences between the gender of patients with HF with all areas of knowledge ( signs and symptoms , activities and exercise , nutrition and drugs). This results is similar with those of Al-Dori{3}. The table indicates that the mean of scores in female patients were more than males scores in all areas. This result revealed that the females were bear the disease more than males, they follow instructions about medication intake more than males and they also tend to strictly limitations of low salt nutrition , healthy diet and the exercise as advised and consult the doctors or nurse about that. The explanation of these results may be that the progress of age had no positive effects on the knowledge of patients with HF about the disease. While the results in table (5) indicates a significant differences in the areas of knowledge of signs and

50


symptoms activities and exercise. These results may be due to that chronicity of the disease and the progressing of the patient’s age lead them to be more aware about signs and symptoms of the disease in order to minimize the burdens of disease and they practicing the instructions relating to daily activities and exercise correctly. Result of the study regarding the educational levels of patients revealed no significant difference in all areas of knowledge patients toward HF disease (table 6). The explanations of these results may be due to the fact that the chronicity of the disease and the burdens on the quality of life( Q.O.L.) of the patients lead them to know how to manage the symptoms of the disease and tend them to be more positive about following the instructions so that the educational level had no significant difference and their knowledge, unless there is a slight difference in the benefit of higher education. The results of the study also revealed no significant difference between the total knowledge, all areas of knowledge of patients with HF regarding their marital status (table 7). Finally the results of all areas of knowledge of patients regarding their occupation ,table (8) show highly significant differences in the area of activities and exercises and the patient's occupation also significant differences were found at in the area of signs and symptoms and their occupation while the table shows no significant difference in the areas of nutrition and drugs with regard the patient's occupation. Conclusions: 1. Majority of patients with HF were obese and about 3rd of them with obesity

grade 3. 2. Patients with HF had good knowledge concerning the disease. 3. No significant differences were found between the total knowledge of

patients with HF regarding some socio-demographic characteristics of the patients such as age groups, gender, occupations, level of education and marital status.

4. Slightly significant difference was found in the all areas of patient’s knowledge about HF regarding the variables of the study.

Recommendations: 1. Continuous increasing knowledge patients with HF in order to minimize the

complications of disease. 2. Pamphlet and instructions should be published and distributed to the patients

in order to appliance the illness instructions about nutrition controlling, fluid restriction, positive exercise and control body weight.

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3. Nurses and health providers should take their role in educating the patients with HF and their families to understand and applied special care and protective measures to minimize the risk of the disease.

4. Health education should be done through different mass media to inform the whole population about the risk factors of HF and increasing patients knowledge regarded the HF in order to reducing the hazards of the disease.

5. Continuous education and training programs for specialized nurses who deal with HF.

References:

1. Abood, D, Black, D, and Feral, D:Nutrition worksite intervention for university staff: application of the health belief model. Journal of nutrition education and behavior, Vol 35, No. (5), 2003, P1499-4046.

2. AL-Baddranii, M, A: Left ventricular dysfunction in acute ST-Elevation MI, UnpublishedThesis, University of Mosul, 2005, P 1.

3. AL-Dori, J, A: HF in the young prospective study at Baghdad teaching hospital, UnpublishedThesis, University of Baghdad,1998, P 1.

4. Boyd, M, W, and Tower, B, L: Medical surgical nursing, 2nd edition, Philadelphia, Saunders company, 2013, P22-25.

5. Carpenter, C ,J, Griggs, R, C, Loscalzo, J, and Andreoli, T, E:Cecilessentialsof medicine, 5th edition, Philadelphia London’s Lious, Saunder company,2001,P 56-59.

6. Christensen, B, L, and Kockrow, E, O: Adult health nursing, 4th edition, St.Louis, Mosby, 2003, P 315-319.

7. Coats, A: The real-Life management of HF. Cardiology, Vol 9, No (2), 2002, P82-88.

8. Dallongeville, J, Marecaux, N, Cottel, D, Bingham, A, and Amouyel, P: Association between nutrition knowledge and nutritional intake in middle-aged men from northern France. Public health nutrition, Vol 4, No (1), 2000, P27-33.

9. Fuster, V, Alexander, R, W, and Orourke, R, A: Pathophysiology of the heart, 11th edition, New York, the McGraw-Hill Company, 2004, P 697-702.

10. Galiff, R, M, and Oconnor, C, M:B-Blocker therapy for HF.JAMA , Vol 283, No(10), 2000, P 100-102.

11. Gelzer-Bell, R and Gurbel, P, A: Diastolic HF in the older patient. Clinical Geriatrics, Vol 13, No(1), 2005, P 18-21.

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12. Glass, R, M, Lynm, G, and Stevens, M, L:HF. JAMA, Vol 285, No (22), 2002, P 120.

13. Goldman, L, and Ausiello, D: Text book of medicine, 22nd edition, Philadelphia, Saunders Company, 2004, P 291-294.

14. Grodner, M, Long, S, and Deyoung, S: Foundations and clinical application of nutrition a nursing approach,3rd edition, St Louis, Mosby, 2004, P 598-599.

15. Grady, K, L, Dracup, K, Kennedy, G, and Moser, D,K et al :Team management of patients with HF. Circulation, Vol 102, No (19), 2000, P 2443-2450.

16. Graham, M, G, Decaro, M, V, and Weinberg, N, M: chronic HF essential of optimal treatment. patient care, Vol 38, No (7), 2004, P 44-46.

17. Gustafsson, F and Arnold, M: HF clinics and outpatient management: review of the evidence and call for quality assurance. European Heart Journal, Vol 25, No (18), 2004, P 1596-1604.

18. Harkreader, H: Fundamentals of nursing, 1st edition, Philadelphia,Saunders company , 2000,P 1112-1115.

19. Hillege, H, L, Girbes, A, Kam, P, and Boomsma, F et al: Renalfunction,Neurohormonal activation and survival in patients with chronic HF. Circulation, Vol 102, No(2), 2000, P 203-209 .

20. Hobbs, R: Give patient a solution for HF. Health and Aging, Vol 10, No(4), 2002, P 54-56.

21. Kenchaiah, S, Evans, C, Levy, D, and Wilson, P et al: Obesity and the risk of HF, The New EnglandJournalof Medicine, Vol 347, No (5), 2002, P 1.

22. Kitzman, D, W, Little, W, C, Bruber, P, H, and Anderson, R, T et al: Path physiological characterization of isolated diastolic HF in comparison to systolicHF. JAMA,Vol 285,No(24),2003,P 72-73.

23. Lilly, L, S: Pathophysiology of heart disease, 3rd edition, Philadelphia,Lippincott Williams and Wilkins, 2003, P 211-214.

24. Luther, T:HF the ABC Digest of urban cardiology, Vol 3, No (1), 2005, P 17. .

25. Markowitz, A, J, and Rabow, M, W: Palliative care for patients with HF. JAMA, Vol 292, No (14), 2004, P 1744.

26. Marshall, H, Sommerville, J, and Kelly, R: Can the sign guideline on HF due to LVSD (Left ventricular systolic dysfunction) be implemented in to general practice. The BritishJournalof Cardiology, Vol 8, No (2), 2001, P 112-116 .

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27. Metheny, N, M: Fluid and Electrolyte balance, 4th edition,Philadelphia, Lippincott Williams and Wilkins, 2000, P 267-278.

28. Meyer, K, Hajric, R, and West brook, S et al: Hemodynamic responses during leg press exercise in patients with chronic HF. The Americna Journal of Cardiology, Vol 83, No (11), 1999, P 1537-1542.

29. Murberg, T, A: Coping and mortality among patients with CHF. International Journal of Behavioral Medicine, Vol 8, No (1), 2001,P66-69.

30. Rice, R: Home care nursing practice, 3rd edition, Philadelphia. St.Louis, Mosby, 2001, P 202-203.

31. Sadaniantz, B, T: From hospital to home nurse coordinate continuum of care to improve quality of life for patients with HF. Nursing Spectrum, Vol 17, No (11), 2005, P 12-13.

32. Saxton, D, F, Nugent, P, M, andPelikan,P,K:Comprehensive review of nursing for NCLEX-RN, 17th edition, Philadelphia.St.Louis, Mosby, 2003, P 493-494.

33. Stewart, S, and Blue, L: Improving outcomes in chronic HF, 1ST edition, London, 2001, P 42-43.

34. Stewart, S, and Murray, J: Palliative care of HF. BMJ, Vol 325, No (7370), 2002, P 915-916.

35. Vazir, A, and Colleagues, M: Sleep-disorderd breathing in HF: an opportunity missed. TheBritishJournalof Cardiology ,Vol 12,No(3), 2005, P 171.

36. Vazquez, M, Lazear, S, E, and Larson, E, L:Critical care nursing, 2nd edition, Philadelphia, Saunders company, 1992, P 248-253.

37. William, S, R: Essential of nutrition and diet therapy, 7th edition, St.Louis, Mosby, 1999, P 411-412.

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First International Scientific Conference 29 –30 April 2017 2017نیسان 30 – 29المؤتمر العلمي الدولي األول / ISSN: Issue Two /Al-Kut University College 7419 - 2414 الثانيكلیة الكوت الجامعة / العدد

STUDY SOME PHYSICAL AND MECHANICAL PROPERTIES

FOR ALUMINA – ZIRCONIA COMPOSITE

Ghazi K. Saeed*, F. A. Chyad** and R. H. Yousif*** *Wasit University – College of Basic Education / Science Department /

[email protected] ** Technology University, Material Engineering Department, Baghdad, Iraq.

*** Baghdad University – College of Science / Physics Department.

ABSTRACT

A combination of alumina-zirconia and different zirconia types was developed in the two types of zirconia; un-stabilized zirconia type (monoclinic) and partially stabilized zirconia (PSZ), which percentage about 0-50 vol%. And studying some physical and mechanical properties of prepared samples such as density, particle size , shrinkage, hardness, Young's modulus and fracture strength. Phase definition using X-ray diffraction, and morphology of surface using scanning electron microscope. The results indicated that the use of partially stabilized zirconia is very useful in improving the mechanical properties, especially the fracture toughness.

Key words: Alumina, zirconia, density, shrinkage, hardness, elastic modulus, fracture toughness.

زر�ونیا –دراسة �عض الخصائص الفیز�ائیة والمیكانیكیة لمر�ب الومینا

***رزاق حمید یوسف **فاضل عطیة جیاد *غازي �مال سعید

[email protected]�لیة التر�یة األساسیة –جامعة واسط *

قسم الفیز�اء –�لیة العلوم –جامعة �غداد ***قسم هندسة المواد –الجامعة التكنولوجیة **

الخالصة

غیر المثبتة احاد�ة المیلزر�ونیا ولنسب مختلفة من الزر�ونیا بنوعین –تم تحضیر مر�ب من األلومینا )monoclinic( ) والمثبتة جزئیاPSZ 50-0) والتي �انت �حدود vol% ص صائ، ودراسة �عض الخ

الفیز�ائیة والمیكانیكیة للنماذج المحضرة مثل الكثافة والتقلص �الحجم والصالدة ومعامل المرونة ومتانة الكسر ، �اإلضافة الى فحوصات األطوار �استخدام منظومة حیود األشعة السینیة ، وفحوصات مجهر�ة �استخدام

لكتروني الماسح. واشارت النتائج الى ان استخدام الزر�ونیا المثبتة جزئیا مفید جدا في تحسین المجهر اال الخواص المیكانیكیة و�األخص متانة الكسر.

الكلمات المفتاحیة: األلومینا, الزر�ونیا، الكثافة, التقلص �الحجم, الصالدة, معامل المرونة, متانة الكسر.

INTRODUCTION

Although alumina represent about 25% of the earth crust, it does not very frequently occur in the free form. The common source of alumina are hydragillite or gibbsite

55


Al(OH)3 , bauxite Al2O3.2H2O and diaspor Al2O3. H2O . There are several methods for producing alumina, namely; Bayer process, Pyrogentic process, Peniakoff method, clay method and Chemical process. Pure alumina (α-Al2O3) has a hexagonal structure with two Al2O3 molecules per unit cell[1].

The stable form of zirconia (ZrO2) at room temperature has monoclinic symmetry which on heating transform to a body-centered tetragonal phase and subsequently to a cubic phase. On the basis of high temperature x-ray data, the polymorphic change in which a monoclinic lattice transform to tetragonal lattice between 1100°C and 1200°C, tetragonal to cubic transition at 2370 °C .The crystal structure of ZrO2 can be described as a distortion of the cubic fluorite CaF2- structure. The lattice parameter of various polymorphs of ZrO2 are given in table (1)[2]. The ZrO2- Y2O3 binary system was shown in figure (1) illustrates how are these of four basic microstructure that include the tetragonal ZrO2 toughening agent are fabricated, as shown Y2O3 forms a solid solution with ZrO2 to reduce the tetragonal to monoclinic transformation temperature from ~1200°C ZrO2 to ~600°C for the eutectoid composition containing ~3.5 mol% , addition of ≥7 mol% Y2O3 stabilize the cubic structure to room temperature [3].

Fig.(1) portion of the ZrO2- Y2O3 binary[3] M:monoclinic, T:tetragonal and C:cubic.

Table (1) Lattice parameters of zirconia[2]

Phase monoclinic tetragonal cubic Temp.(°C) 30 1393 2400 a (nm) 0.51415 0.36526 0.5272 b (nm) 0.52056 c (nm) 0.53128 0.52928 β 99°18'

The toughening of alumina by dispersion zirconia particles was first encouraged by the development of the partially stabilized zirconia (PSZ) at 1975 [4]. Claussen who first reported alumina toughened with PSZ dispersions, the initial study was on the

56


dependence of the ZrO2-tetragonal phase on the sintering temperature, the result show that at sintering temperature 1500 for 1 hour and 1600°C for 1 hour, it was shown from transmition electron microscope (TEM) that tetragonal ZrO2 particles with diameter <1µm and a few particles with diameter >1µm have transformed to monoclinic form [5]. Heuer et al. studied the stability of tetragonal ZrO2 particles in alumina at different particle sizes and temperatures, noted that the critical size decrease with volume fraction of ZrO2 increase [6]. Viswanathan et al. [7] as well as Ikuma and Virkar [8] studied the toughness as a function of crack length, the fracture toughness K1c was obtained with range from 5-8 MPa.m1/2 against crack length c1/2 from 4×103 m1/2 -10×103 m1/2. Rule et al. studied the phase dependence of the mechanical properties for zirconia toughened alumina (ZTA) containing 15 vol% PSZ, it was found that a balance of fracture toughness and strength can be controlled by percentage of tetragonal and monoclinic phase in ZTA [9]. Patil and Mutstddy showed that high density for pure alumina 15vol% zirconia with fracture toughness K1c ~4.8 MPa.m1/2 can be obtained by a combination of air sintering and gas over pressure sintering [10]. Injection molding of a mullite–zirconia composite was developed, the rheological and thermal properties of the feedstock were measured and used for mold-filling simulation studies of a miniature turbine stator geometry, the results from the study confirm the ability of fabricate complex shapes made from a mullite–zirconia composite [11]. Experimental Work High purity alumina (α-Al2O3) has been used as starting material, which was supplied by ALM-41-SUMITO-CHEMICAL-COMPANY-U.K., with average particle size 0.64µm. Un-stabilized zirconia was supplied by ZIRCNIUM OXIDE-14603- W.G., with average particle size 1.25µm. Partial stabilized zirconia (PSZ) [ZrO2 plus 5.4 wt% Y2O3] with average particle size 0.39µm. The procedure of work concluded : (A)Agglomeration Technique: The first stage of agglomeration process prepared slip-casting with following steps: (1)Preparation of a mixture of a material powdered (PSZ) and a solution [ distilled water with 1 wt% polyvinyl alcohol (PVA) binder ] into stable suspension which was called slip. (2)Pouring of the slip into porous mold (Gipson mold), that helps in draining some of the water in the mixture and forming a thick layer which is interconnected or adherent to the mold, the non-adherent excess material then has been removed before a complete drying process. (3)Primary drying of the mixture has been achieved by leaving the mold content to dry at ambient temperature for 72 hrs., for complete drying the material has been removed from the mold and entered an oven operating at 90°C for further period of 48 hrs. (4)After slip casting procedure , firing process has been carried out at 1300°C for 2 hrs., in mortar agitates the material has been fragmentation and grinding to smaller parts and then sieved between 25µm-50µm sizes of the PSZ-agglomerated particle which has been used in the present work. Large particle size can be reduced to small particle size using vibrational milling. (B)Mixing, Forming and heat treatment:

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Samples has been prepared in five different categories, in addition to pure alumina (α-Al2O3). Toughening samples have been prepared as follow: Type-I; Al2O3 matrix with dispersed fine PSZ. Type-II; Al2O3 matrix with agglomerates PSZ (25µm-50µm). Type-III;Al2O3 matrix with dispersed fine PSZ plus agglomerates PSZ (25µm-50µm). Type-IV; Al2O3 matrix with un-stabilized ZrO2. Type-V; Al2O3 matrix with un-stabilized ZrO2 plus agglomerates PSZ (25µm-50µm). A block diagram of the samples was shown in figure (2).

Fig.(2) Block diagram showing mixing type of alumina and zirconia In order to convert zirconia weight to volume fraction, the following equation (1) was used [12].

𝑉𝑓 =1

1 +�1 −𝑊𝑓�𝑊𝑓 ×

𝜌𝑓𝜌𝑚

… … … . (1)

where Vf was zirconia volume fraction , Wf was zirconia weight percentage , ρf was density of zirconia and ρm was density of alumina.

The general steps for preparing the samples as listed below: (1)The PVA binder has been thoroughly mixed with distilled water using a motor of speed 75 rev./min. (2)Using the prepared binder 1%wt, alumina matrix has been dispersed at the required concentration of zirconia content. (3)After 2 hrs. of mixing time and to avoid weak attraction, drops of dilute HCl has been added to the above aqueous slurry until PH value of ~3 has been achieved. Further mixing time about 4 hrs. has been required to homogeneous slurry. (4)Excess diluted acid has been percolated and further drying the material with an oven at temperature 90°C for 48 hrs. (5)The dried composite material has been milled with vibrational milling for 30 min to crush the soft agglomerates. (6)The powder has been uniaxial compacted as a cylindrical pellets with a steel die of 10 mm diameter at a pressure of 127 MPa, the pellet called green sample.

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(7)The prepared green samples have been fired at different temperatures for constant time and at constant temperature for different time. These process have been carried out using a Nabertherm furnace W.G., of controlled temperature scheme from 0 to 1700°C , the rate of increasing temperature has been chosen as 3°C/min and cooling rate as 10 °C/min. Specimens of type-IV have been treated especially through cooling, it has been quenched from 1275°C to room temperature. For a constant time (4 hrs.), the effect of temperature has been investigated at 700°C, 900°C, 1100°C, 1300°C, 1500°C, and 1650°C. At firing temperature (1650°C) the effect of firing time has been investigated for 1 hrs., 2 hrs., 4 hrs., 6 hrs. and 8 hrs. Vickers hardness calculated from equation (2) [13].

𝐻𝑣 =1854.4 𝑙

𝑏2… … … (2)

Where l was the load in gm , b was impression of diagonal in µm and Hv hardness in Kg/mm2. Knoop hardness calculated from equation (3)[13].

𝐻𝐾 =14229 𝑙𝑑2

… … … (3)

Where l was the load in gm , d was impression of diagonal in µm and HK hardness in Kg/mm2. The Young's modulus calculated from Knoop hardness from equation (4) [14]. 𝐸 = 0.45𝐻𝑘

0.1406−𝑤𝑑… … … (4)

Where HK Knoop hardness in Kg/mm2 ,d was impression of diagonal in µm, w was the long of short impression in µm , and E was Young's modulus in GPa. Fracture toughness K1c was calculated from equation (5) for Palmqvist cracks ( 0.25 ≤ l/a ≤ 2.5) and calculated from equation (6) for median (half-penny) cracks ( c/a ≥ 2.5) [15].

𝐾1𝑐 = 0.0181(𝐸𝐻𝑣

)0.4𝐻𝑣√𝑎 (𝑙𝑎

)−0.5 … … … (5)

𝐾1𝑐 = 0.0677( 𝐸𝐻𝑣

)0.4𝐻𝑣√𝑎 (𝑐𝑎

)−1.5 … … … (6)

Fig.(3) Vickers impression with cracks Where a was the half – diagonal of the Vickers indent, c was the radius of the surface crack and l = c – a as shown in figure (3).

Results and discussion The spectra of powders for α-Al2O3 , pure un-stabilized zirconia and partially stabilized zirconia PSZ were shown in figure (4), figure (5) and figure (6) respectively.

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Fig.(4) XRD spectrum of pure alumina powder before sintering

Fig.(5) XRD spectrum of pure un-stabilized zirconia before sintering

Fig.(6) XRD spectrum of PSZ before sintering

Figure (7) and figure (8) were shown the densities and shrinkage of samples for alumina after sintering at different temperatures.

Fig.(7) Density of alumina versus temperature Fig.(8) Shrinkage of alumina versus temperature

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The variation of Vickers hardness (Hv) values with the zirconia contents were shown in figure (9), the results gives the maximum values about 10vol% of ZrO2 and then drops from its maximum level to values much lower than that for pure alumina samples. Figure (10) was shown the Knoop hardness.

Fig.(9) Vickers hardness versus volume fraction of zirconia

Fig.(10) Knoop hardness versus volume fraction of zirconia

Figure (11) was shown Young's (E) modulus as a function zirconia percentage, the composite Al2O3-ZrO2 (PSZ-fine) have the highest values. Figure (12) was shown fracture toughness (K1c) as a function zirconia percentage, all the fracture toughness have the same behavior increase and decrease around zirconia volume fraction 10-20 vol%, except the composite Al2O3-ZrO2 (PSZ-fine) for type(I) was continuous increasing until zirconia volume fraction reach value 50vol%.

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Fig.(11) Young's modulus versus volume fraction of zirconia

Fig.(12) Fracture toughness versus volume fraction of zirconia

Figure (13) was represent scanning electron microscope (SEM) of pure alumina with sintering temperature 1650°C and time 4hrs. for surface alumina (a) and grain fracture surface of alumina (b), which shown the growth of polycrystalline in three dimensions (regular crystalline construction). Figure (14) was shown SEM of type (I) PSZ-fine for composite Al2O3-25vol%ZrO2 with sintering temperature 1650°C and time 4hrs, and figure (15) with same composition and heat treatment was shown photograph of optical microscope for Vickers impression, which show the cracks from corners of Vickers impression.

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(a) (b)

Fig.(13) SEM of alumina with sintering temperature 1650°C and time 4 hrs., (a) surface alumina and (b) Grain fracture surface of alumina.

Fig.(14) SEM of Al2O3-25vol% ZrO2(PSZ-fine) Fig.(15) Hv impression of Al2O3-25vol% ZrO2

CONCLUSION

• Full densification occurs using pure alumina at ultimate conditions 1650°C for 4 hrs.

• Hardness values of all types (I-V) are increased to their maximum values at concentration ~ 10 vol% zirconia in alumina matrix.

• Young's modulus decreases while zirconia concentration increasing for all types.

• Fracture toughness increase to a maximum value and then suddenly decreases with concentrations for types (II-V). For type (I) the K1c values increase while zirconia concentration increase at the range which has been used .

REFRENCES

[1]I. J. McColm ,"Ceramic science for materials technologists" Leonard, (1983).

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[2]E. C. Subbarao, H. S. Maiti and K. K. Srivastava, "Material transformation in zirconia", Phys. Stat. Sol. 21. 9 (1974) pp 3-39.

[3]F. F. Lange and N. E. Claussen, "Some processing requirement for transformation toughened ceramics", in Ultrastructure processing of ceramics , glass and composites, edited by Larry L. Hench and Donald R. Ulrich, by John Wiley and sons, Inc., (1984) pp 493-525.

[4]R. C. Garvie, R. H. Hanink and R. T. Poscoe, "Ceramic steel', Nature (London), 258 (1975) pp 703-704.

[5]N. Claussen, "Stress induced transformation of tetragonal ZrO2 particles in ceramic matrices", J. Am. Ceram. Soc. 61 [1-2] (1978) pp 85-86.

[6]A. H. Heuer, N. Claussen, W. M. Kriven and M. R. Ruhle, "stability of tetragonal ZrO2 particles in ceramics", J. Am. Ceram. Soc. 65 [12] (1982) pp 642-649.

[7]L. Viswanathan, Y. Ikuma and A. V. Vickar, "transformation toughened of β*-alumina by incorporation of zirconia", J. Mater. Sci., 18 (1983) pp 109-113.

[8]Y. Ikuma and A. V. Virkar, "crack – size dependence of fracture toughness in transformation- toughened ceramics", J. Mater. Sci., 19 (1984) PP 2233-2238.

[9]M. Ruhle, A. G. Evans, R. M. McMeeking , P. G. Charalamide and J. W. Hutchinson, "Micro crack toughening in alumina/zirconia ", Acta Metall 35 [11] (1987) pp 2701-2710.

[10]D. S. Patil and B. C. Mutsuddy, "Processing and properties of zirconia-toughened alumina ceramics", Bull. Matter. Sci., 17 [7] (1994) pp 1435-1439.

[11]R. Martin, M. Vick, M. Kelly, J. Palagi de Souzac, R. K. Enneti and S. V. Atre, " Powder injection molding of a mullite–zirconia composite", J. mater. Res. technol. 2 [3] (2013) PP 263–268.

[12]R. Kleinholz and G. Molinier, "Aramid fiber, carbon fiber and glass fiber specialized reinforcement materials for composites", Vetrotex [22] march (1986).

[13]S. H. Avner, "Introduction to physical metallurgy", Second edition, by McGraw-Hill, Inc., (1974).

[14]D. B. Marshall, T. Noma and A. G. Evans, "A simple method for determining elastic-modulus-to-hardness ratios using Knoop indentation measurements", J. Am. Ceram. Soc., 65 (1982) C175-C176.

[15]A. G. Evans and E. A. Charles, "Fracture toughness determinations by indentation", J. Am. Ceram. Soc., 59 [7-8] (1976) pp 371-372.

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First International Scientific Conference 29 –30 April 2017 2017نیسان 30 – 29المؤتمر العلمي الدولي األول / ISSN: Issue Two /Al-Kut University College 7419 - 2414 نيالثاكلیة الكوت الجامعة / العدد

Experimental And Theoretical Estimation Of Hourly Based

Solar Irradiance In Baghdad Khalid S. Shibib1,Mohammed A. Munshid2, Dr.Mohammed Sellab Hamza And

Haneen D. Jabbar3 1, 2Department of Laser and Optoelectronics Engineering, University of

Technology, Iraq

[email protected]

ABSTRACT: -In this work, the solar irradiance components were calculated theoretically using a program based on the theory that presented by ASHRAE standard based on latitude 32.2 in Baghdad. Solar irradiance components (Direct normal, diffused direct normal radiation and reradation) were measured practically except the last one at Baghdad using asolar power meter. Theoretically, the created program that based on the theory that presented by ASHRAE standard on latitude 32.2 in Baghdad can calculate hourly based direct normal, diffused direct normal and their sum for any day through the year with atime step of 15 min, assumed the local time was converted to solar time based on ASHRAE. A good nearby result were obtained between theoretical and practical data for the two solar irradiance components which confirm the used theory and experimental setup.

KEYWORDS:Solar irradiance, Direct normal, Diffused direct normal, Solar power meter.

1. INTRODUCTION Solar radiation is electromagnetic waves that emitted from the sun, it can travel

through extraterrestrial space without interacts with matter, and can reach the atmosphere of theearth to undergo physical and chemical processes and can be scattering by molecules, tiny particles that are in air, and dust which results in diffused solar light radiation. The solar light radiation that incident on the surface of earth consist of total solar light radiation, direct normal solar light radiation, diffuse solar light radiation, and reflected solar light radiation from surrounding (1). The actual amount of sunlight radiation that can reach a specific place on the earth is variables. Also the regular both the daily and the yearly variation relate to the clear movement of thesun, the irregular variations are caused by local atmospheric conditions, like clouds. These conditions specifically affect the direct and diffuse sunlight components. The direct light radiation is part of the solar light that is direct can reach the surface of the earth in a straight line. While ascattering of the solar light in theatmosphere, produce thediffuse light component. A part of the solar light radiation that can be reflected by thesurface of the earth is called reflected light component, also may be found in the total solar light radiation unless avoided. A total or global solar radiation is used to mention the total solar light radiation that is a collection of these three solar light components. The solar irradiation is solar irradiance integrated over aperiod of time (2). Abdul latiffetal.Studied the behavior of extraterrestrial, global, diffused, and beam radiation

65



and compares them with those measured by themetrological station. The effect of collector tilt angle is also presented. Results, in general, showed a good closeness between calculated and measured radiations for almost cases (3). M.T.Y. Tedrasetal suggested an empirical simple equation which was obtained to estimate the global horizontal solar radiation (GHSR) as a function of the latitude only and three empirical models proposed to estimate the GHSR using 17 different locations across Iraq. The models formulated as Quadratic, 2nd Fourier and 2nd Gaussian expression. The simply input feature beside a fine predictive ability for modeling and a good agreement showed by comparison with observed values for 21 years with accuracy15%(4).Falehet al.studied the solar radiation over the region of Iraq. They suggest empirical models for the estimation of Global Solar Radiation depending on Sunshine Hours on Horizontal Surface in various cities in Iraq where empirical constants for these models were estimated and the results obtained by these models were tested statistically. The results showed a good agreement between estimated and measured values (5).Hadil .J.Assimeasure the values of global solar radiation (G) for stations in Baghdad, Basrah, Mosul, and Rutba,which were used for years 1984, 1994, and 2004.Those data were supplied by the NASA National Administration of Space Agency.The monthly average daily number of hours of bright sunshine data (N) was obtained from the Iraqi meteorological organization(6).

In this work, the irradiance solar components were obtained theoretically and the resultswere compared with experimental data. The good nearby result confirms the used theory and correctness of the experimental setup. The result that obtained from this work is an important aspect to those who works on thesolar cell, calculation of irrigation requirements, civil and communication engineering that required the temperature distribution through soil.

2. THEORY

2.1 Solar Irradiation Equation The total solar irradiation Itθof a terrestrial surface of any orientation and tilt

with an incident angle θ is the amount of the direct normal element IDN Cos θplus the diffuse elementIdθcoming from the sky plus the element of reflected shortwave radiation Irthat can reach the surface from the earth or from adjacent surfaces (7):

Itθ= IDN Cos θ +Idθ+Ir (1)

Where:

Itθ:-The amount of radiation and the diffuse solar radiation on a surface, also called as global radiation on the surface (W/m2) (8).

IDN:-Direct normal radiation (W/m2).

θ:-The angle between the beam radiation that incident on a surface and the normal to that surface (8).

Idθ:-Diffused radiation on ahorizontal surface (W/m2).

66


Ir:-Reflected radiation (W/m2).

Stephenson (9) suggested that the intensity of the direct normal irradiation IDNat the surface of theearthon a clear day can be calculated by (7):

IDN= A𝑒−𝐵cos𝛽 (2)

Where:-

A:- Apparent extraterrestrial intensity at m=0.

B:- Atmospheric extinction coefficient.

β = The solar altitude angle between the horizontal surface and the line to the sun that is the complement of the zenith angle (8).

Both A and B are functions of the date and take into account the seasonal difference of the earth-sun distance and the air’s water vapor content. The values of the both elements A and B can be found in many references (7).

This equation can be utilized to estimate the value of diffuse radiationIdθthat arrivea tilted or vertical surface (7)that is a sun-oriented radiation got from the sun after its direction has been altered because of diffusing by the environment (atmosphere). Diffuse solar light radiation is alluded to in some meteorological literature as sky radiation or sunlight based sky radiation (7):-

Idθ= C IDNFss (3)

Where: C:-Ratio of the diffuse radiation on a horizontal surface to the direct normal irradiation (7).

Fss:-The angle factor between the surface and the sky.

Fss =1+cosΣ

2 (4)

cos θ = cos β cos γ sin Σ + sin β cos Σ (5)

Where:-

β = The solar altitude angle between the horizontal surface and the line to the sun that is the complement of the zenith angle (8).

γ = The Surface azimuth angle that is deviation of the projection on a horizontal surface of the normal to the surface from the local meridian, with zero to the south, east negative, and west positive; −180◦ ≤ γ ≤ 180◦(8).

Σ = The tilt angle.

2.2 Solar Angles The axis about which the earth rotates is tilted at an angle of 23.45° to the plane

of the earth’s orbital plane and the sun’s equator. The earth’s tilted axis results in a day-

67


by-day difference of the angle between the earth-sun line and the earth’s equatorial plane called the solar declination δ. This angle differs with the date, the declination can be estimated by this equation (7):-

δ=23.45 sin [360° 284+N365

] (6)

Where: N= year day.

The relationship between declination angle (δ) and the date from year to year differs to an insignificant degree. The everyday change in the declination is the essential explanation behind the altering seasons, with their variation in the dispersion of solar radiation over the world's surface and the fluctuating number of hours of daylight and darkness (8).

The earth’s rotation causes the sun’s apparent motion as shown in Fig.(2.1),the position of the sun can be specified as far as its altitude angle (β) over the horizon (angle HOQ) and its azimuth angle (φ), can be themeasuredangle (HOS) in the horizontal surface. At solar noon, the sun is exactly on the meridian, which contains the south-north line. Consequently, the solar azimuth φ is 0°. The noon altitude βNis was given by this equation (7):-

βN=90◦- LAT +δ (7)

Where:-

LAT:- is latitude.

δ:- Solar declination .

Since the earth is rotating day by day and its yearly orbit around the sun are regular and able to be predicted, the solar altitude and azimuth can be readily evaluated for any time of day when the latitude, longitude, and date (declination) are known. Apparent solar time (AST) can be utilized, expressed as far as the hour angle (H) (7),

Where:-

H= (number of hours from solar noon)*15◦ (8)

Or

H = number of minutes from solar noon4

(9)

Where:-

H :-The angular displacement of the sun east or west of the local meridian due to rotation of the earth on its axis at 15°per hour; at morning is negative, at afternoon is positive (8).

2.3 Solar Time The apparent solar time (AST) basically varies from the local standard time

(LST) or daylight saving time (DST), and the variation can be significant, particularly

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when DST is in effect. Since the sun appears to move at the rate of 360° in 24 h, its apparent rate of motion is 4 min per degree of longitude. The apparent solar time (AST) can be determined from the following equation (7):-

AST=LST + Equation of Time + (4min) (LST meridian – Local longitude) (10)

Where:-

AST: Apparent solar time,

LST: local standard time.

LST meridian: local standard time meridian.

To find the solar altitude (β) and the azimuth (φ) when the hour angle (H), the latitude LAT, and the declination δ are known, this equation can be used (8):

sinβ = cos(LAT) cos δ cos H + sin(LAT) sin δ (11)

sinϕ = cos δ sin H/ cosβ (12)

Or

cosϕ = sinβ sin (LAT)− sin𝛿cosβ cos (LAT)

(13)

3. EXPERIMENTAL WORK

3.1 Calculation of Solar Radiation Components Solar radiation components (Direct normal and diffused direct normal) were calculated theoretically using a program based on the theory that presented by ASHRAE standard which was created based on latitude 32.2 in Baghdad. The program cancalculate the hourly based direct normal, diffused and reradiating component of solar radiation. The program could calculate these parameters for any day through the year with atime step of 15 min.To obtain the result that needed in our work, the program was modified to calculate the direct normal, direct normal diffused components of solar radiation and their sum for any day through the year. Assuming the local time was converted to solar time based on ASHRAE standard (7).

3.2 Measurement of Solar Radiation Components The hourly based direct normal component of sunlight was measured using solar power meter (TES 1333R, Taiwan, ranging from 0-2000 W/m2) placed at the end of a pipe 1 (cm) in diameter , length of 50 (cm)which is inside coated by black color to absorb the diffused and reflected component of sunlight so as almost the direct normal components of solar light is passed through pipe as it directed normal to the sun(9), in Baghdad from the sunshine to sunrise every 15 min. and the local time was converted to solar time based on ASHRAE standard for specific days through the year 2016 (21 Mar., 21 May, 21 Jun., 21 Aug.). Diffused direct normal light intensity was measured also using solar power meter (TES 1333R,Taiwan,ranging from 0-2000 W/m2) fixed at

69


the end of the pipe of 6 cm in diameter and 8 cm in length coated with white color from inside and black shaded to reflect all the incoming diffused solar component (10).

4. RESULTS AND DISCUSSION

4.1 Calculations of Solar Radiation Components Solar radiation components (Direct normal and diffused direct normal and reradiationsolar light components) were calculated theoretically using the above-mentionedprogram that based on the theory presented by ASHRAE standard which was created based on latitude 32.2 in Baghdad. The calculation was carried outfor the 21 days in each month. The Direct normal and diffused direct normal solar components and their sum are shown in figs(2-13) for every 21 days in the months through the year.

4.2 Measurementsof Solar Radiation Components and Comparing Results The hourly based direct normal component of sunlight was measured using solar power meter (TES 1333R, Taiwan, Ranging from 0-2000 (W/m2)) placed at the end of a pipe 1 (cm)diameter with 50 (cm) in length which is inside coated by black color to absorb the diffused and reflected component of sunlight so as almost the direct normal components of solar light is passed through pipe as it directed normal to the sun(10). The measurementwascarried out in Baghdad for only specific days through the year (i.e. 21 Mar, 21 May, 26 Jun., 8 Aug.) assumed the local time is converted to solar time.It is found that as the solar time increased solar irradiance components (Direct normal and diffused direct normal radiation) increased too until it reaches its maximum value at noon then it decreased to sunrise. It is to be noted that every reading has been repeated for 10 times by followingchauvenent's criterion (11).Some bias readings have been dismissed then average values were taken which regarded as the acceptable readingfor solar light radiation component. Direct normal and diffused direct normal radiation were compared and good nearby results were obtained as shown in Figs. 14-25.

From figs mentioned aboce , it was observed that the direct normal solar components reach its max. value in Jun, and the max. diffused direct normal components reach its max. at Jun. This is due to the movement of earth about its axis and about the sun and due to the weather condition in Iraq.

5. CONCLUSIONS A program based on the theory presented by ASHRAE standard was created based on latitude 32.2 in Baghdad which calculate the hourly based direct normal, diffused and of solar radiation for any day through the year with atime step of 15 min, assumed the local time was converted to solar time based on ASHRAE standard. Solar irradiance components (Direct normal and diffused direct normal radiation) were measured and compare with that obtained theoretically. Good nearby results were obtained which confirm the used mythology and experimental setup. The obtained data can be used successfully as input power to thesolar cell to standardized solar components in

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Baghdad and can be used also in predicting soil temperature that could be used in civil and communication engineering.

REFERENCES [1] A.R.Jhp,Ph.D., "Solar Cell Technology and Applications",Taylor and Francis group,2010.

[2] Askari Mohammad Bagher, Mirzaei Mahmoud AbadiVahid, and Mirhabibi Mohsen, "Types of Solar Cells and Application", American Journal of Optics and Photonics, 3(5): 94-113, 2015.

[3] Dr. Abdullateef A. Jadallah1, Dr. Dhari Y. Mahmood, and Zaid A. Abdulqader," Estimation and Simulation of Solar Radiation in Certain Iraqi Governorates", International Journal of Science and Research (IJSR),volume 3, issue 8 , 2012.pp: 945-949

[4] M. T. Y. Tadros, M. A. M. Mustafa, and M. Abdel-Wahab, "Estimation of the Global Horizontal Solar Radiation in Iraq", International Journal of Emerging Technology and Advanced Engineering, Volume 4, Issue 8, 2014, pp: 1-19.

[5] Faleh H. Mahmoodand GheidaaSabeeh Al-Hassany, "Study Global Solar Radiation Based on Sunshine Hours in Iraq", Iraqi Journal of Science, Vol 55, No.4A, 2014, pp: 1663-1674.

[] Hadil .J.Assi,"Estimating Global Solar Radiation on Horizontal Surface for Selected Stations over Iraq", Al- Mustansiriyah J. Sci., Vol. 24, No 1, 2013,pp: 1-12.

[7] ASHRAE, "Applications Handbook (SI)", In: Solar energy use, 2003.

[8] Muhammad Iqbal, "An Introduction to Solar Radiation", University of British Columbia, 1983.

[9] Stephenson and D.G, "tables of solar altitude and azimuth; intensity and solar heat gain tables", Technical paper: division of building research, national research council of Canada, No. (243), Ottawa, 1967.

[10] John A. Duffie, and William A. Beckman, "Solar Engineering of Thermal Process", In: Available Solar Radiation, Fourth Edition, 2013, pp: 44-48.

[11] J. P. Holman,"Experimental Methods for Engineers", in theanalysis of experimental data, eighth ed., southern Methodist university, 2012, pp: 60-112.

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Figure (1). Apparent everyday path of the sun that shows solar altitude (β) and solar

azimuth (φ) angles [7].

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Figure 2: Hourly based direct normal and diffused normal solar light component during 2016.

74


Figure 3: Comparison between experimental and theoretical values of direct normal light intensityduring 2016 at Mar, May, Jun, Aug; dashed line (theoretical), triangle (experimental).

75


Figure 4: Comparison between experimental and theoretical values of direct normal plus diffused direct normal during Mar, May, Jun, Aug; solid line (theoretical), triangle (experimental).

76


Figure 5: Comparison between experimental and theoretical values of direct normal diffused solar light intensity during at Mar., May, Jun Aug.; dashed line (theoretical), triangle

(experimental).

77


لحساب التجریبي والنظري لالشعاع الشمسي في بغدادا الخالصة

في ھذا العمل، قد تم حساب مكونات اإلشعاع الشمسي نظریا باستخدام برنامج معتمد على النظریة المقدمة بواسطة ASHRAE االشعاع في بغداد وقد تم قیاس مكونات اإلشعاع الشمسي (المباشرالعمودي، 32.2على أساس خط العرض

بغداد باستخدام جھاز قیاس الشدة الشمسیة. من الناحیة فى) عملیا اشعاعھ عائدماالشعاع الوالمنتشر المباشر العمودي في بغداد 32.2على أساس خط العرض ASHRAEالنظریة، البرنامج المنشىء الذي یعتمد على النظریة المقدمة بواسطة

خطوة ي یوم خالل السنة مع یمكنھ حساب شدة االشعاع المباشر العمودي والمنتشر المباشر العمودي ومجموعھما في اتم خطوط الطول والعرض والیوم، بفرض ان التوقیت المحلي تم تحویلھ إلى التوقیت الشمسي باالعتماد على محدده زمنیة

دقھ نظریة المستخدمة والالحصول على نتائج جیدة قریبھ بین البیانات النظریة والعملیة لمكونات اإلشعاع الشمسي التي تؤكد اجھزة القیاس.

78


Preparation and Study the Electrical Properties of CuS Nano crystalline Thin Films.

Dr. Suad M.Kadhim1 Dr.Ayad Z.Mohammed1 dr.Talib Z.al-Mosawi2 1 Laser &Optoelectronics Eng. Dep.,Technology University, Iraq

2 Laser &Optoelectronics Eng. Dep., Al-kut University College ,Iraq Email: [email protected]

Abstract : In this work Nano CuS were prepared by using CDB technique. The

CuSO4 salt was used as a source of copper ions, many growth

parameters have been considered in this work. Ion copper concentration

was varied from (0.02-0.08M) at 40°C and the deposition temperature

was change from (50-80°C) at 0.02M. The thickness of CuS increases

with increasing Copper ion concentration and deposition concentration

and deposition temperature. The electrical conductivity change from

(3.8-12.9Ω.cm)-1 The thermal activation energy changed from (0.125-

0.816) eV`. The Concentration and Mobility of carriers reach to values

(7.83*1019) cm-3 and (25.88) cm2/V.sec.

:الخالصة

الترسیب تقنیة باستخدام النانویة النحاس كبریتید أغشیة تحضیر تم العمل ھذا في

وبعض النحاس الیون مصدر تكون لكي النحاس كبریتات امالح استخدمت. الكیمیائي بالحمام

من تغیره تم النحاس ایون تركیز. العمل ھذا في االعتبار بنظر اخذت التحضیر معامالت

)0.02-0.08 (M حرارة درجة عند °C 40 بمدى الترسیب حرارة درجة تغیر تم ذلك °C

وكذلك النحاس ایون تركیز بزیادة ازداد االغشیة سمك. )0.02 ( M تركیز عند) 50-80(

12.9-3.8( تغیرت قد الكھربائیة التوصیلیة ان لوحظ. الترسیب حرارة درجة بزیادة

(Ω.cm)-1 0.816-0.125( من تغیرت التنشیط طاقة كذلك) eV( الحامالت لتراكیز قیم اعلى

.cm2/V.sec )25.88(و cm-3 )1019*7.83( كانت والتحركیة

79



1-Introduction:

Semiconductors are a group of materials having electrical

conductivity between metals and insulators. The electrical properties of

the semiconductors materials are function of temperature, optical

excitation, magnetic field, electromagnetic and impurity content [1,2].

Multi component materials like compound semiconductor and their

alloys are of considerable technical interest in the field of electronic and

optoelectronic devices. It is difficult to prepare these materials in bulk

form due to the limited solubility of materials in each other, in addition

their growth is costly process [3,4]. From this point much effort has

been taken to prepare thin films. In thin films, deviation from the

properties of the corresponding bulk materials arise because of their

small thickness, large surface - to - volume ratio and unique physical

structure which is a direct consequence of the growth process[5].

Copper sulfide is an important semiconductor material and has received

a great deal of attention due to its unique physical and chemical

properties [6]. The energy band gap of CuS, ranging from 1.2 to 2.35 eV

and has p-type conduction is attributed to free holes from acceptor levels

of copper vacancies [7]. CuS as a material, particularly in its thin film

form, has received particular attention since discovery in 1954, by

Reynolds et al., of the photovoltaic effect in heat-treated Cu contacts on

CdS [8]. The properties of CuS thin films are affected by accurate

stoichiometry, which depends on preparative conditions used for the

thin film deposition. CuxS thin films have recently received considerable

attention due to numerous technological applications[9]. It has been

used in photovoltaic application, such as Cu2S/ CdS solar cell which

demonstrated an efficiency of around 10% [10, 11].The active layer in

these cells is the chalcocite ( Cu2S ) film such as Cd1-yZny S/ Cu2S

80


cell[12]. In the photo thermal conversion of solar energy (as solar

absorber coating) [13,14] as in selective radiation filters on architectural

windows (for solar control in Warm climates in electro conductive

coatings), deposited on organic polymers [15] .The most striking benefit

obtained by utilizing CuS as sensor material is the low operating

temperature for sensor application [16,17] .

2- Experimental Work:

2-1 Substrate Preparation:

Substrate used for deposition CuS thin films is microscope glass

slides (25.4 mm x 76.2mm x 1mm) washed in distilled water to remove

the impurities and residuals from substrate surfaces, followed by rinsing

in chromic acid (1mg of CrO3 in 20ml of distilled water) for one day to

introduce functional group called nucleation centers, which formed the

basis for the thin films growth and finally washed again with distilled

water.

2-2 Solution Preparation:

CuS thin films were deposited by using chemical bath deposition

technique. The total volume of the deposition bath was 50ml made from

the flowing constituents

1. Different Molarities of Copper sulfite CuSO4 (0.02- 0.08 M)

2. 0.2M of Sodium Hydroxide Na OH

3.0.2 M of Thiourea SC (NH2)2

4.0.2 M of Tri ethanolamine (TEA)

5. Distilled Water

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3- Deposition of the CuS Films:

Films were deposited on glass substrate by mixing of copper

sulfide(CuSO4), Sodium Hydroxide(NaOH) ,Thiuorya ,TEA and

distilled water(40 ºC). The substrate was immersed vertically in beaker

containing, the reaction mixture and Sodium hydroxide solution were

then added to the beaker. The PH (11-12) was monitoring with PH

meter type (BIBB company). Deposition time was one hour in each

experiment. The substrates were taken out, washed with distilled water

and the procedure is repeated many times (with fresh solutions) to

increase the thickness.

4- Measurements:

4-1 Thickness Measurement:

Copper sulfide thickness was measured by using an optical

interferometer method employing He-Ne laser (0.632µm) with incident

angle 45°. This method depends on the interference of the laser beam

reflected from thin film surface and then substrate the films thickness

was determined using the following formula [18] :-

d = (∆x/x).λ/2 ……………………..(1)

Where x is the fringe width, ∆x is the distance between two fringes and

λ is the wavelength of laser light.

4-2 Electrical Measurements:

To measure the electrical properties, an ohmic contact deposited via

thermal evaporation technique. The Edward E 306A coating system was

used for this purpose, under pressure of about 10-6 Torr. Al wires of

99.999 purity give suitable Ohmic contacts.

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4-3 Current-Voltage Measurements:

Current - voltage measurements carried out. By applying voltage on the

sample from a stabilized DC. Fine power supply, type L 30-2 Farnell of

range (10 - 50)V . The current passing through the device was measured

using Keithley (602) electrometer. From the curve of current –voltage

the resistance (R) could be calculated. The electrical resistivity of the

deposited films was determined using the equation [19]:-

R =ρ L/A …………………….(2)

Where ρ, is the electrical resistivity of the films, L the distance between

electrodes and A the area of the ohmic contacts.

4-4 Activation Energy:

The change thin film resistances with temperature was achieved by

putting the sample inside the Cryostat on the copper plate with Zener

diode, and it was attached to a thermocouple connected to digital meter,

where the Cryostat kept under vacuum to prevent oxidation of the films.

Also the sample was connected to Keithly to record the current as a

function of temperature. By plotting ln (I) vs. (1000/T) the activation

energy could be calculated using the following equation [20]:-

Ea= 0.0864 * slope …………………………(3)

4-5 Hall Effect Measurements:

Preliminary Hall effect measurements were made to determine the

semiconductor conductivity type. The magnetic field of value (0.06

Tesla) perpendicular was applied to the electric field supplied by power

supply (100 -500 volts), it yielded a current (I) then the transverse

electric voltage “Hall voltage VH” was set across the sample, hence the

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Hall coefficient (RH) , carrier density and μh are calculated by applying

the relations [21]:-

RH =1/Nq …………………………..(4)

σeh =Nqµeh …………………………(5)

The sign of Hall coefficient (RH) determines the type of the

semiconductor that is under investigation

5- Result and Discussion:

5-1 Kinetics of Growth:-

5-1-1 Copper Ion Concentration Effect:-

Figure (1) shows the growth is strongly influenced by the molarity of

Copper Sulfate. The deposition rate increases with increasing Copper

ion concentration ,the terminal thickness first increases, passes through a

maximum value and then approximately saturated with increasing

Copper ion concentration (as above 0.08M).

Fig.( 1) : Thickness of CuS Films as a function Molarities value at 40 C°.

In the case being that the copper ion concentration is low ,the number of

(Cu2+) ions insufficient to combine with all the available (S2-) ions ,but

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in the case of high concentration more (Cu2+) ions become available to

form CuS that leading to greater thicknesses.

5-1-2 Temperature Effect:

CuS thin films will be deposited if the ionic product (IP) of (Cu2+)

and (S2-) exceeds the solubility product (SP) of CuSO4. Figure (2)

shows the growth kinetics of CuS films with the deposition time

(60min) at different four temperatures. Throughout the figure, we can

observe that the terminal thickness increases with increasing the bath

temperature, where the heating of the solution helps the decomposition

of the reactants and produces the ions which are very necessary for film

formation .In addition to that it provides kinetic energy to the ions,

resulting in increased number of collisions and hence combination to

form CuS leading to increase terminal thickness with increasing in bath

temperature.

Fig. (2): Thickness of CuS thin film as a function of different deposition Temperatures at M=0.02

85


5-2 The Electrical Properties:

5-2-1 Electrical Conductivity:-

The electrical conductivity was calculated from the current-voltage

curve. Figure (3A,B) reveals that all deposited film show ohmic

behavior whatever the deposition condition .It is clear from figure

(3A,B) that the current of the sample is increase linearly with applied

voltage .

Fig (3 A):I-V Characteristic for different Ion Copper Concentration at(T=40°C).

86


Fig. (3 B) I-V Characteristic for different Temperatures at concentration (0.02M).

The electrical conductivity of the CuS films which deposited at different

deposition conditions was found to be in the range 3.8-12.9 (Ω.cm)-1.

The effect of different deposition conditions to the electrical

conductivity is shown in Figure (4A,B) The figure (4A) reveals the

conductivity of CuS films increase with increasing of copper sulfite

concentration ,where could be attributed to the increasing of average

grain size which is accompanied by a decrease in the grain boundary

scattering . The presence of Cu atoms within the film structure which

was deposited with 0.02 M acted to the increases of electrical

conductivity because serving as strong donors. And the conductivity

increases as increasing in concentration until at molarity 0.08 M the

density of Cu atoms increased within the film structure and then the

conductivity decreased. The decreasing of the conductivity at this

87


molarity (0.08 M) refer to that Cu atoms may serve as scattering centers,

reducing the mobility which in turn increase in the resistivity. In figure

the bath temperatures shows clear effect on the conductivity of CuS

films, where the conductivity reveals slight increase at temperature

range (50-80°C).

Fig(4) :Variation in conductivity as a function of deposition parameters, A)Ion Copper concentration B) Deposition temperature

5-2-2 Activation Energy:

Figure (5A,B) indicates the relationship between lnб and 1000/T

for CuS films, the activation energy (Ea) where can be calculated using

equation (3) . It can be recognize two regions in Figure for all the films

which deposited at different deposition parameters. For the first region

is low temperature region with value of activation energy equal

0.152eV.The second region is high temperature region with value of

activation energy equal 0.816eV.

88


Fig(5A): plot of ln(σ) with 1000/T for(0.02)M different at different Ion copper

Fig(5B): plot of ln(σ) with 1000/T for(0.02)M different at different deposition temperature.

89


5-3 Hall Effect Measurements:-

Figure (6A) show the variation of carrier concentration and mobility as a

function of ion Copper concentration on the other hand, figure(6B) show

the variation of carrier concentration with different deposition

temperature . From the figure we found the value of carrier's

concentration decreases with increasing of deposition morality while

carriers mobility increases. These results may be attributed to the

average grain size increasing with deposition morality.

Fig. (6A): The Relationship between the Hall Concentration and Mobility with different Ion copper concentration

Fig. (6B): The Relationship between the Hall Concentration and Mobility with different deposition temperature.

90


6 - Conclusion:

1-The resistivity decreases with increasing in ion copper concentration

and bath temperature.

2-The activation energy decreases with increases in ion copper while it

increases with deposition temperature.

3- From the Hall effect measurements we found the Hall concentration

in the film more than electron concentration , so the CuS film is P-type .

4- The carrier's concentration decreases with increasing of deposition

morality while it increases with deposition temperature increases.

References:

1- B.G. Streetman and S.K. Banerjee, "Solid State Electronic Devices" 6th Prentice Hall, New Jersey, (2006).

2- H. Zhang, X.Ma, J.Xu and Yang D.Yang, “Synthesis of CdS Nanotubes by Chemical Bath Deposition” Journal of Crystal Growth 263 (2004) 372-376.

3 -H. Zhang, X. Ma, J. Xu , J. Niu, Sha and D. Yang," Directional CdS Nanowires Fabricated by Chemical Bath Deposition" Journal of Crystal Growth 246 (2002) 108-112.

4- Santheep K. Mathew, N.P.Rajesh, Masaya Ichimura and

Udayalakshmi" Preparation and Characterization of Copper Sulfide

particles by Photochemical Method" Journal of Materials Letters 62

(2008) 591-593 .

5- Luminita Isac, Anca Duta, Angela Kriza, Simona Manolache and

Marian Manu," Copper Sulfides obtained by Spray Pyrolysis - Possible

Absorbers in Solid-State Solar Cells", Journal of Thin Solid Films 515

(2007) 5755-5758 .

91


6 - E. Aperathitis , F. J. Bryant and C. G. Scott," Evaporated Copper

sulphide Layers for all-Vacuum Evaporated CuxS/CdS Solar Cells"

Journal of Solar Energy Materials 20 (1990) 15-28 .

7- M. Ashr and S.A. Fayek," Radiation Effects on Fabricated Cu2S/CdS

hetero Junction photovoltaic cells" Journal of Renewable Energy,Vol.

23 (2001) 441-450.

8- P.Harrison, "Quantum wells, Wires and Dots", John Wiley and Sons,

Ltd., 2004.

9-A.F.Mohammad, "Study of Laser Effect on Porous Silicon

Properties", Ms. Thesis, Applied Science Dept., University of

Technology, 2006 .

10- E. Pentia , L. Pintile," Chemically Prepared Nanocrystalline PbS

Thin Films" Journal of Optoelectronics and Advanced Materials ,Vol. 3,

No.2 (2001) pp525-530 .

11- M.B.O. Lopez, M.S. Lerma, A.M.Galvan and R.R.Bon," Optical Properties of Nanostructure in CdS at Different Condition Bath Deposition" Journal of Thin Solid Film 457 (2004) 278-284 .

12- H.M. Pathan , J.D. Desai and C.D.Lokhande," Modified Chemical Deposition and Physico-Chemical Properties of Copper Sulphide (Cu2S) Thin Films" Journal of Applied Surface Science 202 (2002) 47-56.

13- Swarup Kumar Maji and Nillohit Mukherjee" Deposition of Nanocrystalline CuS Thin Film from a Single Precursor: Structural, Optical and Electrical Properties" Materials Chemistry and Physics ,130 (2011) 392–397.

14- P. Parreiraa, G. Lavareda " Transparent p-type CuxS Thin Films"Journal of Alloys and Compounds 509 (2011) 5099–5104.

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15- V.P.Malekar and V.J.Fulari " Studies on Surface Deformation of Copper Sulphide Thin Films by Holographic Interferometry Technique" Journal of Optik 122(2011)1069-1072.

16- kasap, Safa O “Principles of Electronic Material and Device “, Mc Graw-Hill Companies, 2002.

17- S. Dhar and S. Chakrabarti," Properties of chemically deposited Cu2 S films on porous silicon" journal of Applied. Phys. 82(2) (1997) 655-657.

18- M.T.S Nair, Laura Guerrero and P.K Nair," Conversion of Chemically Deposited CuS Thin Films to and by Annealing" journal of Semi cond. Sci. Technol. 13 (1998) 1164-1169.

19- R.A Orozco-Teran, , M. Sotelo-Lerma, " Pbs-Cds Bilayers Prepared by the Chemical Bath Deposition Technique at Different Reaction Temperatures" Journal of Thin Solid Film, Vol.343-344 (1999) 587-590.

20 - S. Bini, K. Bindu, M. Lakshmi and Renew “Preparation of CuInS2 Thin Films using CBD CuxS films", Journal of Energy 20 (2000) 405-413.

21- A. Galdikas A.Mironas, V. Struzdiene, A.Selkus J.Ancultiene and V.Janickis," Annealing Effect on The Structural and Optical Properties of CuS Thin Film Prepared By Chemical Bath Deposition (CBD)" Journal of Sensors Actuators B 67 (2000) 76 .

93

First International Scientific Conference 29- – 30 April 2017 2017نیسان 30 – 29المؤتمر العلمي الدولي األول / ISSN: Issue two / Al-Kut University College 7419 - 2414 / العدد الثانيكلیة الكوت الجامعة

Size Dependence of the Dielectric Susceptibility of Nonsolid Amorphous Silicon

Hussein K. Mejbel, Nadhal M. Abdul-Ameer and Moafak C. Abdulrida*

Department of Physics / College of Education for Pure Science (Ibn Al-Haitham) / University of Baghdad

* Department of Laser and Optoelectronics Engineering, Kut University College, Wasit, Iraq

[email protected]

Abstract The relative change of the susceptibility of amorphous silicon quantum dots of

1.8~4.8 nm have been studied, since the Bohr radius of silicon is about from 4.5 to 5

nm. Deeper insight is presented that the dielectric susceptibility of a nanosolid

depends functionally on the crystal binding that determines the band gap and hence

the essential processes of electron polarization, and on the electron-phonon

interaction. With reduction of the particle size results bond length constriction and

increasing in the bond energy for an atom that located at the surface due to

coordination number deficiencies. The dielectric susceptibility was decreasing with

decreasing of quantum dot size. A blueshift in photo absorbance edges will be

resulted by the suppression of the dielectric susceptibility.

Keywords: dielectric susceptibility, amorphous silicon, atomic coordination number (CN) diminution, nanometric semiconductor.

1. Introduction The electric susceptibility is a dimensionless proportional constant which referred to the degree of polarization of a dielectric of the material in response to an applied field. When the electric susceptibility large in material that means the efficiency of material to polarization large in subject to the electric field, consequently the total electric field diminishes within the material. In this case the electric susceptibility effects on the electric permittivity for material and therefore effects on another phenomena in the medium such as the capacitance for capacitors and the velocity for light [1]. A quantum effects for a solid become significantly important when the solid is reduction to the nanoscale. The coordination number CN diminution for a nanometric semiconductor causes the rise in the surface to volume ratio, the expansion in the band gap (EG) [2] which gives rise to the blue shift in the photoemission and photoabsorption edges and the inner energy levels of the core band shifts towards higher binding energy [3]. The bond-

94


https://en.wikipedia.org/wiki/Polarization_(electrostatics)

https://en.wikipedia.org/wiki/Dielectric

https://en.wikipedia.org/wiki/Electric_field

https://en.wikipedia.org/wiki/Permittivity

https://en.wikipedia.org/wiki/Capacitors

https://en.wikipedia.org/wiki/Speed_of_light


order-length-strength (BOLS) correlation is effects by CN deficiencies which is increase with decreasing the quantum dot size[4]. The promotion of the bond strength (energy) contributes to the increases of the atomic cohesive energy that contributes to the Gibbs free energy that determines the thermodynamic behavior of the system, as well as increases to the energy density of an atom located in the surface region [5-7]. This subject has fund less attention in the investigation of how the change in dielectric constant is affected with the nanostructure semiconductors. Therefore, it is very interesting to build in a model to satisfy the reduction in dielectric constant of semiconductors in case of nanostructure.

2. Theory We used three shells model to calculation the relative change of the dielectric susceptibility. The structure for nanoparticle consist of three shells or three layers which are the core, the subsurface and the surface where the bond length, bond energy, or bond strength are dependent upon the coordination number in these layers or these regions i.e. different in different shells [8].

It is noted in this model that the length of bond will shrink and the bond energy increase in surface region, in the subsurface region there is a contraction a little in the bond length and does not change in the bond energy while in the core region both the bond energy and the length unchanged are the same as that of bulk Si [8]. The bond length constriction result of the coordination number deficiencies. The remaining bonds of the lower coordination atom will contracting spontaneously leading to the increase of the binding energy. The surface bond constriction and the high in surface to volume ratio are responsible for the decreasing of the dielectric constant of nanosemiconductor [4]. The effective CN of an atom in the atomic layer ith is 𝑧𝑧𝑖𝑖 , where 𝑧𝑧𝑖𝑖 varies with the particle size owing to the change of the surface curvature. For a silicon spherical dot of any size𝑧𝑧2 = 6 , 𝑧𝑧3 = 12 , and 𝑧𝑧1 takes the following value [9,2,10] :

𝑧𝑧1 = 4 �1 −0.75𝐾𝐾

� (1)

And

𝐾𝐾 =𝐷𝐷

2𝑑𝑑0 (2)

where 𝐾𝐾is the number of atoms that alignment in radius of a spherical dot, 𝐷𝐷.is diameter of a nanosolid and, 𝑑𝑑0 = 0.263 𝑛𝑛𝑛𝑛 [13] is the bond length value for bulk particle size of a silicon. The formulation for BOLS association is a specific [11]:

𝑐𝑐𝑖𝑖(𝑧𝑧𝑖𝑖) =𝑑𝑑𝑖𝑖𝑑𝑑0

=2

1 + 𝑒𝑒 (12 − 𝑧𝑧𝑖𝑖)(8𝑧𝑧𝑖𝑖)

(3)

where 𝑐𝑐𝑖𝑖 is the bond constriction coefficient that differs from layer to layer [2, 12].

95


The volume or the ratio of number a specific atomic shell, indicated i, into full solid (bulk) as [13,14]:

𝑌𝑌𝑖𝑖 =𝑁𝑁𝑖𝑖𝑁𝑁

=𝑉𝑉𝑖𝑖𝑉𝑉

=𝜏𝜏𝐾𝐾

(1 −𝑖𝑖 − 0.5𝐾𝐾

)𝜏𝜏−1𝑐𝑐𝑖𝑖 (4)

𝑌𝑌𝑖𝑖 isthe surface-to-volume ratio or the volume portion of the ith atomic shell (di thick) (𝑁𝑁𝑖𝑖) compared to the entire solid (𝑁𝑁), 𝐾𝐾 is the No. of atoms that alignment in radius of a nanosolid. 𝜏𝜏 is the dimensionality of a spherical dot (𝜏𝜏= 3), a rod (𝜏𝜏=2) and a thin plate (𝜏𝜏= 1 of any size, that is the dimensionless . Obviously, the shape (𝜏𝜏) and the size (𝐾𝐾) affects on 𝑌𝑌𝑖𝑖 of the particle , and deferent from shell to shell (ci), hence the quantized factors of 𝑌𝑌𝑖𝑖should be evident at smaller 𝐾𝐾values. The relative change of the susceptibility χ can be obtained by [3]:

∆𝜒𝜒(𝐾𝐾)𝜒𝜒(∞) = −

∆𝐸𝐸𝑃𝑃𝑃𝑃(𝐾𝐾)𝐸𝐸𝑃𝑃𝑃𝑃(∞) +

∆𝑑𝑑𝑖𝑖(𝐾𝐾)𝑑𝑑

(5)

The blueshift of the 𝐸𝐸𝑃𝑃𝑃𝑃 and𝐸𝐸𝑃𝑃𝑃𝑃 may be related to the CN diminution- induced bond constriction [10]:

𝛥𝛥𝐸𝐸𝑃𝑃𝑃𝑃(𝐾𝐾)𝐸𝐸𝑃𝑃𝑃𝑃(∞) ≅�𝑌𝑌𝑖𝑖

𝑖𝑖≤3

(𝑐𝑐𝑖𝑖−𝑚𝑚 − 1) − 𝐵𝐵�𝑌𝑌𝑖𝑖𝑖𝑖≤3

(𝑐𝑐𝑖𝑖−2 − 1) (6)

For a nanosolid, the mean of lattice constant ( ∆𝑑𝑑𝑖𝑖𝑑𝑑

) change relatively with supported to emerging from nothing great than the CN-diminution-induced bond constriction, the magnitude of the alteration rely on the fraction of surface atoms which different with the size and shape of the nanosolid. The constriction of the mean lattice of a nanosolid, follows the relationship [15]:

∆𝑑𝑑𝑖𝑖(𝐾𝐾)𝑑𝑑

= �𝑌𝑌𝑖𝑖𝑖𝑖≤3

(𝑐𝑐𝑖𝑖 − 1) (7)

Substituting equation (6) and equation (7) in equation (5) we get:

∆𝜒𝜒(𝐾𝐾)𝜒𝜒(∞) = −�∆𝐻𝐻 − 𝐵𝐵∆𝑒𝑒−𝑝𝑝� + ∆𝑑𝑑 (8)

where

∆𝐻𝐻= �𝑌𝑌𝑖𝑖𝑖𝑖≤3

(𝑐𝑐𝑖𝑖−𝑚𝑚 − 1) (9)

∆𝑒𝑒−𝑝𝑝= �𝑌𝑌𝑖𝑖𝑖𝑖≤3

(𝑐𝑐𝑖𝑖−2 − 1) (10)

∆𝑑𝑑= �𝑌𝑌𝑖𝑖𝑖𝑖≤3

(𝑐𝑐𝑖𝑖 − 1) (11)

And 𝐵𝐵 is the interaction coefficient for the e-p. ∆𝐻𝐻 , ∆𝑒𝑒−𝑝𝑝 and ∆𝑑𝑑 denotes the contribution from the atomic coordination number deficiencies perturbed

96


Hamiltonian, the e-p interaction and the change in length of the bond in the relaxed surface shell. In a Si quantum dots in the form of spherical, 𝑛𝑛=4.88,𝐵𝐵= 0.91, it is an adjustable parameter a representative of the nature of the bond (varies with the nature of the bond) or introduced to describe the change of binding energy with the reduced bond length. For metals (elemental solid), m=1 [17] for compounds and alloys, m=4[11].

3. Results and Discussion When the quantum dot size reduce, that leads to a decrease in the number of atomic coordinates of the atom located at the surface which in turn leads to a bond length contraction of atoms at the surface also leads to increasing of bond energy at the surface.

When we adopt the three shells model, which was established by Professor Sun based on Pauling's and Goldschmidt theories. The structure of a nanoparticle is consist of three shells (three layers; the core, the subsurface and the surface). In this model for different size, the thickness for each of the surface and subsurface layers is almost independent of particle size while the increase of particle size lead to an increasing in the core layer in a proportional manner. By equation (1) which we determined the number of atomic coordinates of the atoms at the surface depending on the quantum dot size, we find that the number of atomic coordinates approximately equal 3.123(CN ≈ 3.123) for dot size from 1.8 nm, then increase to reach 3.671 (CN = 3.671) for dot size 4.8, where the particle size ranges in this study from 1.8 to 4.8 nm, as shown in Figure (1).

Figure (1): Coordination number as a function of particle size.

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At a surface region, the bonds contracts and the bond energy increase with decreasing of CN, whereas at subsurface region the bonds contracts a little but the bond energy keeps invariant, which the bond length and the bond energy are the same as the bulk in the core region. It is concluded that the increase of bond energy results from the CN reduction. If the coordination number decreases from z0 to zi the bond length contracts from 𝑑𝑑0 to 𝑑𝑑𝑖𝑖 , where 𝑑𝑑𝑖𝑖 = 𝐶𝐶𝑖𝑖𝑑𝑑0 . The 𝐶𝐶𝑖𝑖 is the contraction factor, which related to coordination number in equation(3). In silicon naondot z2=6, z3=12 and z1 is related to quantum dot size in equation(1). The measurement of the contraction factor 𝐶𝐶1 and the effective of CN reduction (z1) of an atom in the surface layer is shown in figure (2), which shows the CN dependence of the reduced bond length, 𝐶𝐶𝑖𝑖(𝑍𝑍𝑖𝑖). It is observed that the value of bond contraction factor is 0.84 for coordination number (CN=3) and its equal 0.876 for CN=4.

The study shows that the bond contraction at a surface dominates the size and shape dependency of nanometric materials in many aspects such as the mean lattice contraction, blue shift in photoluminescence, dielectric suppression [18,19].

Figure (2): Relationship between bond contraction factor (C) versus coordination

number (Z) of an atom in quantum system.

We can calculate the relative change of the susceptibility of amorphous silicon by using equation (8) and relying on the three shells model. The results show that the value of susceptibility is less than its value in the case of bulk which is equal to 10.4[20] to 2.36 of the size of quantum dot 1.8 nm and then it start to increase in value with increasing quantum dot size up to 7.31 for the size of quantum dot 4.8 nm. Depending on the susceptibility, it is possible to calculate the relative change of dielectric constant (real part), (∆𝜒𝜒/𝜒𝜒 = ∆𝜀𝜀𝑟𝑟/(𝜀𝜀𝑟𝑟 − 1)). From Figure (3), we find that the relative change as a percentage decreases with increasing the size of quantum dot. We find that the relative change of quantum dot 1.8 nm, which is

98


corresponding to K=3.422 (K is the number of atoms that alignment in radius of the quantum dot), equal to -77% is that the percentage to the extinction in the value of the dielectric constant is 0.77 and the negative signal indicating the suppression. But, it was found that the percentage of the suppression decreases with increasing size of quantum dot up to 0.29 for the quantum dot size 4.8 nm, which corresponds to the value of K = 9.125. This is in agreement with the results publication in the literature [2, 16]. In keeping with the BOLS correlation, the coordination number diminution results extinction for dielectric of a nanosolid [2].

Figure (3): Size dependence of the dielectric susceptibility of amorphous silicon

nanosolids.

4. Conclusions

The three shells model was being adopted in this work, in keeping with this model the silicon nanoparticle categorized into three layers. The external layer is the surface layer, the layer which followed is the subsurface layer and the internal layer is the core layer. In the surface region the bond constriction and the bond strength increases, the bond constriction a little and the bond strength does not change at the subsurface region, whereas in the core region both the bond length and the bond strength unchanged as the same as the bulk. The reduction of the nanoparticle size leads to the increasing of coordination number shortage which casus increases in the bond length constriction and the bond strength. The coordination number shortage of

99


nanosemiconductor due to the extinction of the dielectric constant, this leads to a blueshift of the photoabsorption edges,, which can be used to in multiple applications.

References

1. C. François., Materials Handbook, A Concise Desktop Reference (2nded.).London, Springer-Verlag, pp. 524, (2000). 2. L. K. Pan, C.Q Sun, T. P.Chen, S. Li and B.K. Tay, J.Phys.Chem. B 106 11725,

(2002). 3. L. K. Pan, C.Q Sun, T. P.Chen, S. Li, C.M. Li and B.K. Tay, " Dielectric suppression of nanosolid silicon", School of Electrical and Electronic Engineering, Nanyang Technological University, 639798, Singapore, Nanotechnology 15, 1802–1806, (2004). 4. W. H. Zhong, C. Q. Sun, B. K. Tay , S. Li , H. L. Bai and E. Y. Jiang, J. Phys.: Condens. Matter 14 L399, (2002). 5. C. Q. Sun , Y. Wang, B. K. Tay, S. Li , H. Huang and Y. Zhang , J. Phys. Chem. B 106 10701, (2002).

6.. C. Q. Sun , C. M. Li, S. Li and B. K. Tay, Phys. Rev. B 69 245402, (2004).

7. Q. Weihong, B. Huang, and M. Wang, " Bond-Length and - Energy Variation of Small Gold Nanoparticles", J. Comput. Theor. Nanosci. 2009, Vol. 6, No. 3, 635–639, (2009).

8. L. Lu, Y.F. Shen, X.H. Chen, L.H. Qian and K. Lu,"Ultrahigh strength and high electrical conductivity in copper", Science,304:422-6, ( 2004). 9. L.K. Pan, C.Q. Sun," Coordination imperfection enhanced electron-phonon interaction in nanosolid silicon", J. Appl. Phys.,95, 3819–3821, (2004). 10. C. Q. Sun, S. Li, and B. K. Tay, Appl. Phys. Lett. 82, 3568, (2003). 11. C. Q. Sun, X. W Sun, B. K. Tay, S. P. Lau, H. T. Huang andS. Li," Dielectric suppression and its effect on photoabsorption of nanometric semiconductors", J. Phys. D: Appl. Phys., 34, 2359-2362, (2001). 12. C. Q. Sun, H. Q. Gong, P. Hing and H. T. Ye, Surf. Rev. Lett. 6L171, (1999). 13. C. Q. Sun, J. Phys., Condens. Matter 11 4801, (1999). 14. C. Q. Sun,

S. Li, and B. K. Tay, " Evidence for surface bond

contraction", Appl. Phys. Lett. 81, 460 (2002). 15. C.Q. Sun," Surface and nanosolid core-level shift: Impact of atomic coordination-number imperfection", PHysical Review, B 69, 045105 ,(2004). 16. C. Q. Sun, X. W. Sun, B. K. Tay, S. P. Lau, H. Huang, and S. Li,J. Phys. D 34, 2359 (2001). 17. C. Q. Sun, X. W. Sun, B. K. Tay, S. P. Lau, H. Huang, and S. Li J. Phys. D, 34, 2359, (2001). 18. C. Q. Sun,Y. Wang, B. K. Tay, S. Li, H. Huang and Y. J. Zhang, Phys. Chem. B, 106, 10701, (2002). 19. C.Q. Sun, "Size dependence of nanostructures: Impact of bond

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http://books.google.com/books?id=PvU-qbQJq7IC&pg=PA524&dq=Electric+susceptibility#v=onepage&q=Electric%20susceptibility&f=false

http://books.google.com/books?id=PvU-qbQJq7IC&pg=PA524&dq=Electric+susceptibility#v=onepage&q=Electric%20susceptibility&f=false

https://en.wikipedia.org/wiki/Springer-Verlag


order Deficiency", School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, (2007).

العزل للسلیكون العشوائي النانوي حجم الجسیمات على ثابتاعتماد

*الزیديموفق كاظم ل و نضال موسى عبد األمیر وحسین خضیر مجب

جامعة بغداد/ الھیثم كلیة التربیة للعلوم الصرفة (ابن /قسم الفیزیاء

األھلیة/ واسط العراق الجامعة * قسم ھندسة اللیزر واإللكترونیات البصریة / كلیة الكوت [email protected]

الخالصة

العشوائي ذو النقاط الكمیة للسلیكون متأثریة العازل الكھربائيدراسة التغیر النسبي ل في ھذا العمل تم 5الى 4,5قطر بور للسلیكون ھو تقریبا من حیث ان نصف ) نانومیتر. 4,8-1,8حجوم تتراوح من (ول

العازل للصلب النانوي تعتمد علي طاقة الربط البلوري والتي تحدد ویقدم نظرة أعمق إلى أن قابلیة .نانومیتر الذي یحدث بین على التفاعلوبالتالي العملیات األساسیة لالستقطاب اإللكتروني, كما تعتمد فجوة الطاقة

اآلصرةوكذلك زیادة طاقة اآلصرةانكماش طول إلىاالنخفاض في الحجم للمادة یؤدي . والفونوناإللكترون قلیل حجم النقاط الكمیة ومع تالذریة. اإلحداثیاتللذرة التي تقع عند السطح وذلك بسبب النقصان في عدد

االنخفاض في قیمة متأثریة العازل ینتج عنھ زیادة في أننقصان متأثریة العازل. كما إلىفان ذلك یؤدي النانوي. طاقة حافة االمتصاص لشبھ الموصل

الذریة, شبھ الموصل اإلحداثیاتنقائص عدد العازل, السیلكون العشوائي, : متأثریةالكلمات المفتاحیة

النانوي.

101




Design and construction of optical fiber sensor to detect PbNO2 in drinking water

Bushra R. Mahdi, Nahla A.Aljabar, Dafer A.Daher, Dunya A.Alfatah Directorate of Materials Research, Ministry of Science & Technology,

Baghdad, Iraq. Abstract:

A fiber-optic sensor based on evanescent wave penetration is presented. Evanescent wave penetration is generated by removing the clad and contact the core with the solution. Testing samples were perpetrated by add a salt of PbNo2 at distilled water to produce different contusion solution. A short unclad portion of a plastic clad silica fiber around (12cm) length acts as the sensing region from (20 cm) total fiber length. The absorption of the evanescent wave changes when the waist cladding refractive index n2 is slightly modified. Consequently, the coupling visibility also changes. By putting the device in the water polluted, the trace amounts of nitrite in water can be detected. The experimental results clearly establish the usefulness of the present technique for detecting very low concentrations. A high sensitivity enables the present device to be used for measuring the nitrite content in drinking water. The results were consistent with the data obtained by standard spectrophotometric method, showing potential of the proposed sensor for practical application.

Keywords: optical fiber sensor, pollution detection, chemical fiber sensor.

األلیاف البصریة للكشف عن نترات الرصاص في میاه الشرب مجستصمیم وبناء

دنیا عبد الفتاح ٬ظافر عزیز الظاھر ٬نھلة عبد الجبار ٬بشرى رزوقي مھدي

العراق. -بغداد - وزارة العلوم والتكنلوجیا -دائرة بحوث المواد

الخالصة:

الشیة .وھذه الموجة المتالشیة تتولد بازالة جزء من متحسس اللیف البصري یعتمد على اختراق الموجة المتقشرة للیف البصري ومالمسة اللب للمحلول بصورة مباشرة. عینات االختبار تحضر من اضافة نسب مختلفة

المالح نترات الرصاص للماء المقطر لتنتج محالیل مختلفة التراكیز.

سم من اصل 12من السلیكا بطول حوالي یحضر المتحسس من ازالة جزء صغیر من قشرة اللیف المصنوعسم. ان تغیر امتصاصیة الموجة المتالشیة یحدث بتغییر معامل انكسار الوسط 20لیف طولھ الكامل بحدود

الوسط المحیط بمنطقة التحسس المغمور بالوسط الملوث بالنترات. تتأثر شدة المحیط. حیث باختالف تراكیز ا على تراكیز الملوث .الحزمة النافذة خالل اللیف اعتماد

تم الحصول على نتائج الحساسیة العالیة للمتحسس مكنت من استخدامھ لقیاس تراكیز النترات في میاه الشرب. .من خالل محلل طیفي وبالتالي یستخدم في التطبیقات العملیة

: متحسس اللیف البصري، كشف التلوث، متحسس اللیف الكیمیائي.الكلمات المفتاحیة

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1. Introduction

Increasingly, ground water supplies are affected by the intrusion of toxic chemicals from industrial discharge, agricultural run-off, chemical spills, and leach ate from landfills and leaking underground storage tanks.

The pollutants in water may be of different forms, which include organic content, phosphates, nitrogen compounds, heavy metal ions, complex anions, etc Organic contaminants (e.g. Biological oxygen demand, pesticides, etc.) enter water supplies through run off of precipitation, introduction of sewage and industrial waste, and accidental spills of industrial organic materials. [Pickering, 2000] Organic contaminants (e.g. Biological oxygen demand, pesticides, etc.) enter water supplies through run off of precipitation, introduction of sewage and industrial waste, and accidental spills of industrial organic materials. Many organic species, including pesticides are very stable but they do not last forever. However, spillages of polychlorinated biphenyl (used in plastic, paints, rubbers, waxes) create problems to human beings because of the toxicity of these materials. The phosphate content can arise from industrial eft1uents or from domestic sewage. Phosphates are a normal constituent of human excreta and not all is removed during sewage treatment. The total nitrogen content of water can be present in many chemical forms like ammonia, nitrite, nitrate, etc. Nitrogen is a constituent of proteins, chlorophyll and many other biological compounds [Yasin, 2012]. Upon the death of plants or animals, complex organic matter is broken down to simple forms like ammonia, nitrite, nitrate, etc. by bacterial decomposition. Other sources of nitrogen in aquatic systems include animal waste, fertilizer industries and waste water discharges. Nitrogen from these sources may be discharged directly into streams or may enter waterway through surface run off or ground water discharge and cause serious problems to human health [Lee, 2003]. Sources of metal ion in natural water include effluent discharge from industry, oxidation and leaching of mine dumps, corrosion of metal surfaces, discharges from domestic and agricultural waste water, etc. Toxic metals that may be dissolved in water include arsenic, barium, cadmium, chromium, lead, mercury, and silver [Lin, 2000]. The nontoxic group includes iron, calcium, magnesium, sodium, manganese, aluminum, copper, zinc, etc.

2. Basic Theory

The evanescent wave principle is used in these works .The conventionally used expression for evanescent wave spectroscopy is:

)exp(0)( ClPPl γ−= (1)

where P(l) and P0 are the power transmitted through the fiber with and without an absorbing liquid over the unclad portion respectively [Lin,2000;Cisco System,2008] , C is the concentration of the absorbing species; l is the length of the sensing region and γ is the molar evanescent wave absorption coefficient, which is given by

mfr αγ = (2)

103


where rf is the effective fraction of the total guided power in the sensing region and αm is the molar absorption coefficient of the absorbing species. However, the fraction rf is different for different modal groups and the expression can be modified to better fit with the experimental results:

∑ −= )exp()( lCIPPl γ0 (3)

where γ are the molar evanescent wave absorption coefficients of different modal groups in a multimode fiber having different penetration depths. However, the mode coupling process is a reversible phenomenon so that the power transferred to the cladding modes will again be coupled back to the core modes [Cao and Duan, 2005]. The radiation intensity thus coupled back will depend on the absorption of the medium surrounding the cladding. This recoupling of the cladding mode power is considered to be the major contributing factor to the observed effect of variation of guided mode intensity with change in absorbance of the surrounding medium. Most of the optical sensors are based on spectroscopic absorption measurements. The detector measures the radiation emitted by the source after travelling through an absorption cell where it is partially absorbed by the target compound. Absorption is wavelength dependent, and compound specific. It is described by the Lambert-Beer law Equation (1).

The spectral absorbance α(λ) is defined as

)()(log 0

)( λλ

λ PPA = (3)

where P0(λ) and P(λ) are the spectral radiation power before and after traveling through the absorbing medium [Aljaber,2013;Maddu et al., 2007].

By comparing Eq. [1] and Eq. [2] the following expression of the spectral absorbance can be derived:

ClA )()( λλ α= (4)

3. Experimental work

A-Preparation of the sensing element Multimode, plastic clad silica fiber (200/380~m) is used for making the sensor element. In order to exploit the evanescent wave phenomenon in the multimode fiber, a known length (l2cm) of the cladding at the middle portion of the fiber is chemically removed and this region acts as the sensing region. To avoid vulnerability of the exposed silica to surface cracking and other damage phenomenon, the removal of cladding is performed carefully with acetone, since it reacts only with plastic and not with silica and hence we get a smooth silica core. B-Sensor cell A sensor cell of 15cm length is designed for taking the water samples containing Nitrate. It is made of cylindrical plastic tube having a diameter of 3cm with inlet and outlet provisions. The optical fiber is introduced into the plastic tube through the holes provided at the sides so that the unclad portion of the fiber is within the plastic tube and remains straight is shown in Fig (1).

104


Fig (1): The plastic cell for contains the water sample. C-Preparation of test solutions Standard water samples having nitrite concentration ranging from 1 ml to 100 ml are prepared by dissolving Lead nitrite in water. Then sulphanilamide solution is added and after 5 minutes N- (I-naphthyl) ethylenediamine dihydrochloride solution is added to each of the prepared sample solutions such that the ratio is 50:1:1. Now, the color of the test solution becomes violet and its color intensity varies with nitrite concentration. These test samples are then allowed to remain for 10 minutes to complete the reaction after which the measurements are carried out. The block diagram and photograph experimental setup of the pH sensor are shown in Fig (2) and Fig (3). The setup is consisting of:

Fig (2): The block diagram of the second pH setup of experimental work.

105


Fig (3): The photograph picture of the experimental setup.

4. Results and Discussions When the unclad portion of the fiber is immersed in the test solution, the evanescent field penetrates into the liquid and interacts with it. Since the wavelength of light passing through the fiber is almost close to the peak absorption wavelength of the solution, strong evanescent wave absorption occurs and it increases with the increase in concentration of nitrite. Fig (4) shows the Intensity spectra of water samples containing different nitrite concentrations in the wavelength range 200–1200 nm recorded using a commercial spectrometer (HR 2000 high-resolution spectrometer Ocean Optics.com). Then Intensity peak of the spectra is at around 595 nm and the intensity of light passing through the solution decreases with the concentration of the colored constituent in the solution. Fig (4): Intensity absorption spectra of water samples containing different nitrite concentrations obtained from the spectrometer.

5. Conclusion Experimental results demonstrate the usefulness of EWFSs in measuring nitrite compounds in water with good sensitivity in the lower concentration range. This establishes that the system can be used for measuring the nitrite content in drinking water and for monitoring the water quality in wells near to fertilizer plants and sewage systems. References: Aljaber N..A. (2014). Design and construction fiber sensor detection system for water nitrite pollution. Int. Org. of Sci. Res. J. of Eng., 04(02): 37-43.

Cao W. and Duan Y. (2005). Optical fiber-based evanescent ammonia sensor. Sensors Actuators B, 110: 252–259.

Cisco Systems. (2008). Fiber Types in Gigabit Optical Communications. Printed in USA, C11-463661-00 04/08.

Lee T. S. (2003). Design, Fabrication And Characterization Of Fiber Optic Sensors For Physical And Chemical Applications. PhD thesis. India: Cochin University of Science and Technology.

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Lin J. (2000). Recent development and applications of optical and fiber-optic pH sensors. Trends Anal. Chem. 19(9): 541-552.

Maddu A. , Zain H. , and Sardya S. (2007). The use of polyaniline nanofiber as modified cladding for fiber optic methanol vapor sensor. J. of Opto E. Adv. Mat. 9(8): 2362 – 2366.

Pickering W .F. (1997). Pollution Evolutions the Quantitative Aspects. Marcel Dekken, ince, vol. (2)

Yasin M. (2012). Fiber Optic Sensors. INTECH. Croatia.

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Glucose Concentration Measurement by Fiber Optic Sensor

Mohammed Suham Sada , Nahla A. Aljaber , Farah Zamil Hassan ,

Dr. Bushra R Mahdi Material Science, Ministry of Science and Technology, Baghdad, Iraq

ABSTRACT

In this paper, we present the design and construction of an evanescent wave

fiber optic sensor for Glucose Concentration Measurement. The design of this fiber

optic sensor is based on a cladding modification approach. A step index multimode

fiber with unclad middle region acts as the sensing element. Exposure of this sensing

region to water samples containing different sugar solution concentration causes

evanescent wave absorption, which increases with increasing concentration of

Glucose.

1. INTRODUCTION

Fiber optic chemical sensors have been reported extensively in literatures since

1970’s. The fiber optical sensors have found many application in chemical [1-2],

biochemical and biomedical [3-4], and environmental sensing [5-6].

Predominately, Fiber optic chemical sensors are classified as intrinsic and

extrinsic type sensors. Figures (1) show a basic construction of extrinsic FOS and

intrinsic FOS, respectively. In the extrinsic type of sensors the optical fiber is only

used as a means of light transport to an external sensing system i.e. the fiber

structure is not modified in any way for the sensing function. Intrinsic fiber optic

Sensors, the fiber optic structure is modified and the fiber itself plays an active role

in the sensing function [7, 8].

Fig (1) (a) Extrinsic fiber sensor and (b) intrinsic fiber sensor.

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Most intrinsic chemical sensors rely on the "evanescent wave" (EW) technique.

In this technique, evanescent wave absorption in an external medium is obtained by

removing a certain region of the cladding of a fiber and allowing interaction of the

evanescent field with the absorbing species in the medium. This external medium,

which acts as the cladding of the waveguide, absorbs the light at the wavelength

being transmitted through the fiber depending on the concentration of the species

which absorbs at this wavelength.

Evanescent wave fiber optic sensor (EWFs) offers a number of advantages,

especially in chemical sensing applications. The interrogating light remains guided

in this type of sensor and no coupling optics is required at the sensing region.

Considerable miniaturization can be offered by adopting this technique. Compared

to bulk optical methods, EWFSs are highly sensitive and can be used to perform

accurate absorption measurements on highly absorbing or scattering media due to a

small effective path length. Moreover, since the reagent phase need not be in

physical contact with the optical fiber, it is also easy to change the reagent phase. In

addition, an EWFS offers significant cost reduction [9–10].

2. THEORY

When the light entering one end of a fiber at a small angle to its axis follows a

zigzag path through a series of total internal reflections (TIR) at the core cladding

interface and propagates to the other end the fiber, a small portion of the incident

field penetrates into the cladding of the fiber. Known as the evanescent wave it has a

depth of penetration (dp), defined as distance from the interface where intensity of

the electric field is reduced to in verse exponentially amount of (e−1) the intensity

at the interface. Depth of penetration of the evanescent wave is described by [11]:

𝐝𝐝𝐝𝐝 =𝛌𝛌𝟎𝟎

𝟐𝟐𝟐𝟐 [𝐧𝐧𝟏𝟏𝟐𝟐 𝐬𝐬𝐬𝐬𝐧𝐧𝟐𝟐 𝛉𝛉 − 𝐧𝐧𝟐𝟐𝟐𝟐]𝟏𝟏 𝟐𝟐�… … … (𝟏𝟏)

109


Where λthe wavelength of the light in the fiber core, n1 and n2 are the

refractive indices of the core and cladding materials, respectively, and θis angle of

incidence at core/cladding interface.

The power transmitted by a fiber optic with cladding locally replaced by an

absorbing medium is given by [12]:

𝐏𝐏 𝐨𝐨𝐨𝐨𝐨𝐨 = 𝐏𝐏𝐬𝐬𝐧𝐧 𝐞𝐞𝐞𝐞𝐝𝐝(−𝛄𝛄𝛄𝛄) … … … (𝟐𝟐) Where L the distance along the unclad fiber length, Pout is the power transmitted in

the absence of an absorbing species. C is the concentration of the absorbing medium

and γ is an evanescent wave absorption coefficient, which is given by[13]:

𝛄𝛄 = 𝐫𝐫𝐫𝐫 … … … (𝟑𝟑)

Where 𝐫𝐫the effective fraction of the total is guided power in the sensing region

and 𝐫𝐫 is the bulk absorption coefficient of the absorbing species.

The evanescent wave absorbance is given by [14]:

𝐀𝐀 = 𝐥𝐥𝐨𝐨𝐥𝐥𝟏𝟏𝟎𝟎𝐏𝐏𝐬𝐬𝐧𝐧𝐏𝐏𝐨𝐨𝐨𝐨𝐨𝐨

… … … (𝟒𝟒)

Or by using intensity:

𝐀𝐀 = 𝐥𝐥𝐨𝐨𝐥𝐥𝟏𝟏𝟎𝟎𝐈𝐈𝐬𝐬𝐧𝐧𝐈𝐈𝐨𝐨𝐨𝐨𝐨𝐨

… … … (𝟓𝟓)

3. EXPERIMENTAL

In order to exploit the evanescent waves in the (SMF) fiber, a known length

(100 cm) of a glass clad silica (GCS) fiber of 10 µm core diameter (9/125 μm) is

chemically removed. The jacket and cladding of the fiber are removed from a length

5 cm of the middle portion of the fiber.

A sensor cell is designed for taking the test liquids containing glucose. It is made

of cubic glass tube having a long the side of cube is 5 cm with inlet and outlet

110


provisions. The optical fiber is introduced into the glass tube through the holes

provided at the sides so that the unclad portion of the fiber is within the glass tube

and remains straight.

A schematic diagram of the experimental set-up for glucose concentration

measurement is shown in figure (2). Firstly we used Deuterium Halogen UV- Vis –

NIR light source, type DH-2000 to find the finger print of liquid solution . This

source is coupled to the fiber optic using connector type (FC),than the effective

wavelength is used 808 nm . When the unclad portion of the fiber is immersed in

test solution, the evanescent field penetrates into the liquid and interacts with it.

Since the wavelength of light passing through the fiber is within the absorption band

of the solution, evanescent wave absorption occurs and it increases with the increase

in concentration of glucose. The output light intensity is detected using a

spectrometer. The spectrometer is provide from (Ocine -HR 4000 CG- UV- NIR)

and personal computer. The spectrum range is from (200 to 1100) nm. The intensity

spectrometer is presented at the screen of personal computer.

Fig(2) Experimental setup of glucose testing.

Preparation of test solutions

The glucose solution is prepared in distilled water for various concentrations ranging

from 0.001 gm/litre to 10 gm/litre. This glucose solution along with Benedict's

reagent (quantitative reagent) are mixed in a pre-decided ratio (1:3) and heated on a

111


Figure (4) Variation of output light intensity with glucose concentration.

boiling water bath for five minutes and allowed to cool for some time. This resultant

solution acts as the test liquid.

4. RESULTS AND DISCUSSION Figure (3) shows the Intensity spectra of water samples containing different glucose

concentrations It is observed from this figure that the intensity decreases due to the

addition of different concentrations of glucose. Clearly, the intensity peak of the

spectra is around (809.25 nm)is shifted to the longer wavelength with increase

concentration of glucose .

Figure (4) shows the variation of the output intensity with glucose concentration.

The change in the intensity can be attributed to the evanescent wave (EW)

absorption taking place in the sensing region. The maximum output intensity is

equal (2796) at (10%), and the minimum (2244) at (50%).

Figure(3). Intensity absorption spectra of water samples containing different glucose concentrations obtained from the spectrometer.

112


Figure(5) The relation Between the glucose construction and maximum power.

The output power of optical fiber sensor is shown in fig (5). From this measurement, it can be inferred that the output power decreases as the glucose concentration increases.

Fig. 6 shows the shifts in wavelength due to changes in the

surrounding concentration changes. From these figures, it is observed

that, the wavelength is shifting towards the higher wavelength as the

concentration increases.

The power loss (in percent) of the laser transmitted through the fiber

optic as a result of evanescent wave was determined with the

following equation:

Δλ with Constration,

0, 0.77 Δλ with

Constration, 10, 0.75 Δλ with

Constration, 20, 0.33


30, 0.15


40, 0.05


50, 0.01

Δλ

Constration

Δλ with Constration

0

10

20

30

40

50

Fig. (6 )Variation on Wavelength with concentration (ppm) of hydrogen peroxide solution.

113


A = −10 log Pout/ Pin where A is the power loss, Pin is the power measured for straight fiber optic, and

Pout is the power measured for deflected fiber optic of the same length. The out-

put power loss as a result of evanescent wave is shown in Fig. 7.

Fig.( 7 )The Absorbance power loss for evanescent wave cell. The sensitivity of this sensor is equal to 0.05 nm / RIU. 5. Conclusion

A fiber optic sensor system depending upon evanescent wave fiber optic

sensor (EWFS) technique have designed and developed for sensitive

measurement of trace amounts of glucose content. ranging from 10% to

50%.

EWFS powered by a laser source and EWFS with a IR laser source.

Experimental results demonstrate the usefulness of EWFSs in measuring

glucose compounds with good sensitivity in the lower concentration

range.

References [1] Wolfbeis, O.S. Fiber optic chemical sensors and biosensors; CRC

Press, Boca Raton, Florida, 1991, 1992; Vol. 1&2. [2] Lieberman R. A.,

Recent Progress In Intrinsic Fiber-Optic Chemical Sensing II, Sensors

and Actuators B, 11 (1993) 43-55.

A

C

0

10

20

30

40

50

114


[2] Wolfbeis, O. S.; Posch, H. E. Fiber optic fluorescing sensor for

ammonia. Anal.Chim.Acta.1986,185, 321-327.

[3] Baker, S. L. R.; Kopelman, R.; Meyer, T. E.; Cusanovich, M. A.

Fiber optic nitric oxide selectivebiosensors and nanosensors.

Analytical Chemistry 1998, 70, 971-976.

[4] Holst, G.; Mizaikoff, B. Fiber Optic Sensors for Environmental

Sensing. Handbook of opticalfiber sensing technology; Lopez-

Higuera, J. M., Ed.; John Wiley & Sons Ltd. ; 2001, p 729.

[5] Mizaikoff, B. Infrared fiber optic gas sensor for

chlorofluorohydrocarbons. VibrationalSpectroscopy 1995, 8,103-

108.

[6] Anderson, F. P.; Miller, W. G. Fiber optic immunochemical sensor

for continuous, reversiblemeasurement of phenytoin. Clinical

Chemistry 1988, 34, 1417-1427.

[7] El-Sherif, M. A. Smart Textiles Created with Embedded Sensors.

MRS Bulletin TechnologyAdvances 2003, 28(2), 101-102.

[8] B D MacGraith, Sens. Actuators B, 11 (1993) 29.

[9] B.D. MacCraith, ‘Enhanced evanescent wave sensors based on sol-

gel derivedporous glass coatings’, Sensors and Actuators B, Vol. 11,

1993, pp. 29-34.

[10] DeGrandpre, M. D.; Burgess, L. W. ,(1990), App. Spec. 44,273-

279.

[11] Kapany, N S. , (1967); Fiber Optics, Academic Press: NewYork.

[12] M Shelly John, P Radhakrishnan, V P N Nampoori and C P G

Vallabhan, Commun. In Instrum. 6 (1998) 107

[13] N.S. Kapany and J.J. Burke, ‘Optical Waveguides’, Academic

Press, New York,1972.27

115


[14] C. Dudley, "Absorption, Fluorescence And Amplified Spontaneous

Emission Of Blue-Emitting Dyes", M.Sc thesis, washington state

university, 2004.

116


Measurement of Plasma Temperature From The Iron lines Appeared of alloy (low-carbon steel) Using Laser-

Induced Breakdown Spectroscopy (LIBS)

Eng. Mohannad H. Hussein 1and Dr. Alaa H. Ali 2, 1 State Company for Construction Industry / Ministry of Industry and Minerals, Baghdad,

Iraq 2 Department of Materials Research / Ministry of Science and Technology, Baghdad, Iraq

ABSTRACT Laser-induced breakdown spectroscopy (LIBS) is a rapid spectro-chemical analysis technique that uses a short laser pulse to create a micro-plasma on the target surface, that used to study atomic emission from the expanding plasma plume formed via the interaction of high peak power Nd: YAG laser with a metal alloy (low-carbon steel). This technique provides valuable information about the configuration of the target material. In this work, alloy (low carbon steel) has been spectrally analyzed by using LIBS technique. The Iron emission lines apparent in the alloy utilized to measure of the excitation temperature assuming the local thermal equilibrium within the plasma. The Saha-Boltzmann method have been used to extract the excited plasma temperature, Measured value of (Te) is the of (6244.55 K°) at the fundamental wavelength. Keywords: LIBS; low-carbon steel; Fe-Lines; Plasma Temperature 1. Introduction

Laser induced breakdown spectroscopy (LIBS) is an analytical chemistry technique for determining the trace elements. LIBS is a useful method that requires optical access to the target surface, and can be used as a quick means for the detection and determine of metals in the different categories of samples. Can be measured several components with this technique at one time.

During the past decades LIBS- technique becomes applied analytical technique distinct used in different application fields, due to its reliability [1], non-contact optical nature and its a sample with little or no preparation [2]. Used in many applications and fields, such as, identify the chemical elements[3, 4], characterization of jewelry products [5], in soil studies [6], cleaning [7] , and the heritage and culture [8], and planetary exploration off-site [9, 10].

In this paper, alloy (low carbon steel) has been spectrally analyzed by using LIBS technique. The Iron emission lines apparent in the alloy

117


utilized to measure of the excitation temperature assuming the local thermal equilibrium within the plasma. The Saha-Boltzmann method have been used to extract the excited plasma temperature, Measured value of (Te) is the of (6244.557 K°) at the fundamental wavelength.

2. PLASMA PARAMETERS In LIBS experiments, after the initial plasma decay and during the entire observation interval, the local thermodynamic equilibrium (LTE) conditions are assumed to hold. For optically thin plasma, the re-absorption effects of plasma emission are negligible. So, the emitted spectral line intensity I is a measure of the population of the corresponding energy level of this element in the plasma [11].

The main parameters of laser Induced Breakdown Spectroscopy (LIBS) are electron density and plasma temperature. LIBS is not a stationary system and typical values for temperature and electron density of LIBs in air range, respectively, between 20,000 K and 10 19 cm −3 in the early times after its formation, and 5,000–6,000 K and 10 17 cm −3 at the late stages of its evolution[12]. The obtained spectra are helpful in extracting the electron density and plasma temperature. The factors that influence the emitted intensity of the plasma are the number density of the emitting species (ions and neutrals), electron density and temperature. These parameters are also responsible for different excitation and ionization processes occurring in LIBS. Many methods have been described for determining the plasma temperature based on the absolute or relative line intensity (line pair ratio or Boltzmann plot), the ratio of lines to continuum intensity, etc... Depending on the experimental conditions [3, 9]. One of these methods may be more suitable than others. Provided that the Local Thermodynamic Equilibrium (LTE) hypothesis is fulfilled, the plasma temperature can be calculated by using the Boltzmann equation to generate a Boltzmann plot, is given by:

𝐼𝐼 =ℎ𝑐𝑐

4𝜋𝜋𝜋𝜋 .𝑁𝑁(𝑇𝑇)𝐴𝐴𝐾𝐾𝐾𝐾𝑔𝑔𝑘𝑘𝑈𝑈(𝑇𝑇) 𝑒𝑒𝑒𝑒𝑒𝑒 �−

𝐸𝐸𝑘𝑘𝐾𝐾𝑇𝑇𝑒𝑒

� ( 1 )

118


where 𝜋𝜋 is the wavelength, 𝐴𝐴𝐾𝐾𝐾𝐾is the transition probability, 𝑔𝑔𝑘𝑘 is the statistical weight for the upper level, 𝐸𝐸𝑘𝑘 is the excited level energy, 𝑇𝑇𝑒𝑒 is the temperature, 𝐾𝐾 is the Boltzmann constants, 𝑈𝑈 (𝑇𝑇) is the partition function. The emitted spectral line intensity from a given state of excitation can be used to evaluate the plasma temperature. The lines must be well resolved for accurately evaluating their wavelengths 𝜋𝜋, intensities 𝐼𝐼, and their transition probabilities 𝐴𝐴𝐾𝐾𝐾𝐾 must be known. Reformulating Eqn. (2) gives:

𝑙𝑙𝑙𝑙 �𝐼𝐼𝜋𝜋

𝐴𝐴𝐾𝐾𝐾𝐾𝑔𝑔𝑘𝑘� = −

𝐸𝐸𝑘𝑘𝐾𝐾𝑇𝑇𝑒𝑒

+ 𝑙𝑙𝑙𝑙 �𝐶𝐶𝐹𝐹𝑈𝑈𝑇𝑇� ( 2)

where 𝐹𝐹 is an experimental factor and 𝐶𝐶 is the species concentration. By plotting the left hand side of Eqn. (2)Vs. the excited level energy 𝐸𝐸𝑘𝑘, the plasma temperature can be obtained from the slope of obtained straight line [13].

The emitted spectral line intensity is a measure of the population of the corresponding energy level of a certain species in the plasma. Under the assumptions that the plasma is both in LTE and optically thin, if we have information on the intensity emitted from several excited levels, we can then determine the Plasma temperature which is responsible for the observed population distribution. The condition that the atomic and ionic states should be populated and depopulated predominantly by electron collisions, rather than by radiation, requires an electron density which is sufficient to ensure the high collision rate. The corresponding lower limit of the electron density is given by by McWhirter criterion [14], by below equation (3).

𝑙𝑙𝑒𝑒 ≥ 1.6 ∗ 1012.𝑇𝑇1 2� . (∆𝐸𝐸)3 ( 3 ) where ∆𝐸𝐸 (eV) is the highest energy transition for which the condition holds, and T (K) is the plasma temperature. This criterion is a necessary, though insufficient, condition for LTE, and is typically fulfilled during the first stages of plasma lifetime. It is, however, difficult to satisfy for the low-lying states, where ∆𝐸𝐸 is large. However, for any ne, it is possible to find high excitation levels where the states are close enough for equation (3) to hold. In this case, the plasma is said to be in partial LTE [15, 16].

119


3. EXPERIMENTAL SET-UP A LIBS system was designed to detect the Fe-plasma in air, as

detailed in Figure 1. Nd:YAG laser operated at the fundamental wavelength of (1064 nm) with a pulse duration of (9 ns) was used for plasma excitation. The fundamental diameter of the laser beam was (5mm) that is focused onto the sample by a plano–convex lens with a focal length of (10cm), the diameter of the focused on the sample was (0.9mm), peak power of the laser pulse (8.89 MW) and power intensity (1.4*109 W/cm2). The sample is placed in the sample holder in ambient atmosphere, the emission from plasma is then collected in front of the plasma with observance to the laser beam direction, plasma emission was collected by (15mm) diameter imaging lens, and focused onto optical fiber type (SMA, 50μm/0.22 NA), which deliver the plasma light to the entrance slit of spectrum analyzer model (CCS-100) with (1200 Line/mm) grating and (20-μm) slit dimension, Which serves to deflect light according to wavelength and then reversed by mirrors to detect and convert optical signals to digital, and then moves the digital signal to the application, which shows us the spectral lines for the sample and then analyzed. During LIBS analysis of alloy (low carbon steel) sample, geometric position of the material surface with respect to laser beam incidence is one of the factors that affect the results.

Figure.1. Schematic diagram of LIBS experimental setup

120


4. RESULTS AND DISCUSSION 4.1 ANALYSIS SAMPLE The analysis sample of alloy (low carbon steel) to determine the emission lines of the Fe-element by technique of LIBS. The plasma emission as shown in Table 1.

Table 1. Analytical lines of the alloy to determine the emission lines of the Fe-metal by LIBS technique.

4.2 DATA ANALYSIS The accurate determination of LIBS emission lines is necessary to identify the chemical components of the sample. Based on the spectral lines of the emission Fe-lines from the alloy (low-carbon steel) and that was analyzed in the LIBS, and depending on National Institute of Standards and Technology (NIST) atomic spectra database [17], was accurate determination of LIBS emission lines. Figures.2 shown typical LIBS spectrum in fundamental wavelength range by using a fundamental wavelength.

Element (Name)

λ (nm)

Fe I 329.8132 434.3271 463.2911 468.0294 472.8545 492.47692 500.18633

Fe II 482.08278 636.2470 655.9888 668.5485

121


Figure. 2. The emission spectrum generated by the 1064 nm laser on Fe-plasma in air at normal atmospheric pressure in the region from (320-680) nm.

The emission spectra displayed in the Figure. 2 was recorded using a fundamental wavelength 1064nm of Nd-YAG Laser, with power laser densities 1.4*109W.cm-2. The spectra was obtained by data of single laser shot (SLS) under normal atmospheric pressure. In our experimental conditions, example to a set of emitted spectrum is given in the range from 320 to 680 nm is shown in Figure 2. Shows the strong lines of Iron appear under the above spectrum, from the spectral lines from the sample can determine the atomic constants used to evaluate the plasma temperature and electron densities from the Fe-lines. Using the transition (3d64s 3p2 → 3d74p 3D2 ) for line FeI 492.47nm with gk= 5, Aki= 4.23 x 105 s-1, Ek = 38678.039 cm-1, used to calculate the plasma parameters. The emission spectrum lines consist of neutral spectral lines of transitions of the Fe-lines. The wavelengths of all the observed spectral lines along with their relevant spectroscopic data are displayed in Table. 2. Depending on the (National Institute of Standards and Technology Atomic Spectra Database) (NIST) [17] and with some of references [18, 19]. The result Te is a straight line with a slope equal to (-1/kTe). The Boltzmann plot for five emission lines [Fe I 463.291, 468.029, 472.85, 492.47 and 668.54 nm] in the single-shot of laser-pulse from laser energy 80mJ, the scheme is shown in Figure. 3. The slope of the curve yields a temperature of 6244.557 K° of the Iron lines. The minimum electron density for Local Thermodynamic Equilibrium

Wavelength(nm)

Inte

nsity

(a.u

)

122


(LTE), expressed as the McWhirter criterion in equation (3) to hold. In the present case ∆E =2.5 eV, and its electron density is (2.015*1015 cm-

3), the plasma is said to be in partial LTE [15, 16].

Table 2. Atomic Spectroscopic parameters of the neutral Iron lines.

Element λ Intensity gA_upper Energy lower level

Energy upper level

name (nm) (relative) (108 s−1) (cm−1) (cm−1) Fe I 329.8132 0.1208 4.51E-01 17 927.382 48 238.847 Fe I 434.3271 0.0986 8.00E-02 26 224.969 49 242.621 Fe I 463.2911 0.1915 3.80E-03 12 968.554 34 547.211 Fe I 468.0294 0.4948 5.12E-04 12 968.554 34 328.752 Fe I 472.8545 1.0000 2.01E-01 29 469.024 50 611.261 Fe II 482.08278 0.2784 5.40E-01 83 136.508 103 874.040 Fe I 492.47692 0.3187 2.12E-02 18 378.186 38 678.039 Fe I 500.18633 0.3181 2.59E+00 31 307.245 51 294.220 Fe II 636.2470 0.3263 5.28E-01 87 985.667 103 698.515 Fe II 655.9888 0.2363 8.00E-08 62 945.045 78 185.004 Fe II 668.5485 0.1351 4.44E-01 88 157.176 103 110.835

Figure. 3. Boltzmann plot for the calculation of the excitation temperature of FeI.

5 Conclusions

In this work, we have constructed a LIBS system by using a portable commercial Thorlabs spectrometer equipped with ICCD detector to Identify spectral lines emitted from a metal alloy (low-carbon steel), the spectral lines were used to evaluate the plasma parameters emitted from the Fe-plasma in air. The plasma temperature and electron density were determined from the plasma formed from the interaction of lasers with the target. Plasma parameters (Te & Ne) are very important parameters to plasma description and give information about the physical condition

y = -1.3598x + 13.094

Te=6244.5 K°

23456789

1011121314

1 2 3 4 5

Eu (in10e3cm−1)

ln(

𝐼𝐼𝜋𝜋/g

A)

123


that has been identified. The results obtained indicate that the LIBS technique is effective and rapid technique to identify the elements and estimate the plasma parameters which saves a lot of time and efforts.

REFERENCE

[1] X. Shen, "Laser-induced breakdown spectroscopy with improved detection sensitivity, selectivity, and reliability", in, 2009.

[2] D.A.R.L.J. Cremers, "Handbook of Laser-Induced Breakdown Spectroscopy ",John Wiley & Sons, pp.69-70 (2013).

[3] R. Noll, "Laser-induced breakdown spectroscopy fundamentals and applications", in, Springer, New York, 2012.

[4] V.M.M.P.N.G. Piñon, "Laser-Induced Breakdown Spectroscopy for Chemical Mapping of Materials", Applied Spectroscopy Reviews, 48 (2013) 357-383.

[5] A. Jurado-López, M.D. Luque de Castro, "Rank correlation of laser-induced breakdown spectroscopic data for the identification of alloys used in jewelry manufacture", Spectrochimica Acta Part B: Atomic Spectroscopy, 58 (2003) 1291-1299.

[6] Walid Tawfik Y. Mohamed, A. Askar, "Study of the Matrix Eff ect on the Plasma Characterization of Heavy Elements in Soil Sediments using LIBS with a Portable Echelle Spectrometer", Progress in Physics, Vol.1 (2007).

[7] F.F. Colao, R.; Lazic, V.; Morone, A.; Santagata, A.; Giardini, A., "LIBS used as a diagnostic tool during the laser cleaning of ancient marble from Mediterranean areas", APPLIED PHYSICS A MATERIALS SCIENCE AND PROCESSING, 79 (2004) 213-220.

[8] H.L. Xu, G. Méjean, W. Liu, Y. Kamali, J.F. Daigle, A. Azarm, P.T. Simard, P. Mathieu, G. Roy, J.R. Simard, S.L. Chin, "Remote detection of similar biological materials using femtosecond filament-induced breakdown spectroscopy", Applied Physics B, 87 (2006) 151-156.

[9] J.P.T.S.N. Singh, "LASER-INDUCED BREAKDOWN", 2007. [10] S. Musazzi, U. Perini, "Laser-induced Breakdown Spectroscopy: Theory and

Applications", Imprint: Springer, 2014. [11] W.M.Y. Tawfik, "Calibration free laser-induced breakdown spectroscopy (LIBS)

identification of seawater salinity", Optica applicata., Vol.37,pp.5-20 (2007). [12] Rosalba Gaudiuso 1, Marcella Dell’Aglio 2 , Olga De Pascale 2 , Giorgio S. Senesi 2

and , Alessandro De Giacomo 1, Laser Induced Breakdown Spectroscopy for Elemental Analysis in Environmental, Cultural Heritage and Space Applications: A Review of Methods and Results sensors

ISSN 1424-8220, 2010, 10, 7434-7468 (2010). [13] W.T.Y. Mohamed, D.o.E.A. National Inst. of Laser Enhanced Science NILES, Cairo

University, Cairo, Egypt, "Fast LIBS Identification of Aluminum Alloys", PROGRESS IN PHYSICS, 2 (2007) 87-92.

[14] R. Gaudiuso, M. Dell'Aglio, O. De Pascale, G.S. Senesi, A. De Giacomo, "Laser induced breakdown spectroscopy for elemental analysis in environmental, cultural heritage and space applications: a review of methods and results", Sensors, 10 (2010) 7434-7468.

[15] A.W.P.V.S.I. Miziolek, "Laser-induced breakdown spectroscopy (LIBS) : fundamentals and applications", PP.3-4 (2006).

[16] K. Yamanouchi, M. Nisoli, W.T. Hill, "Progress in Ultrafast Intense Laser Science VIII", Springer, 2012.

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[17] A. Kramida, Ralchenko, Yu., Reader, J., and NIST ASD Team "NIST Atomic Spectra Database (ver. 5.1)", in, National Institute of Standards and Technology, Gaithersburg, MD. , [Gaithersburg, Md.], (2013).

[18] P.L.S. Robert L. Kurucz, Claas Heise , Jim R. Esmond "Atomic Line Data,Kurucz CD-ROMNo (Smithsonian Astrophysical Observatory, Cambridge)", www.cfa.harvard.edu, 23 (1995).

[19] M. Garcimuño, D.M. Díaz Pace, G. Bertuccelli, "Laser-induced breakdown spectroscopy for quantitative analysis of copper in algae", Optics & Laser Technology, 47 (2013) 26-30.

125

http://www.cfa.harvard.edu/


Study The Structural And Morphological Properties Of Nano Structure Zinc Oxide (ZnO) Thin Films Prepared By RF

Magnetron Sputtering Abdul Hussein K.Elttayef1,N.N.Jandow2 and Abass Maijed2

[email protected] Minstiry of science and technology : 2 Almustansry University, college of education

والمحضرة الخارصین ذات التر�یب النانومتري ألغشیة او�سید التر�یبیة خصائصدراسة ال الترذیذ الماكنتروني ذي التردد الرادیوي �طر�قة

د. عبدالحسین خضیر , د.نضال نیسان جندو , عباس مجید الخالصة :

تم في ھذا البحث دراسة الخصائص التركیبیة ألغشیة اوكسید الخارصین الرقیقة ذات التركیب النانومتري والمحضرة باستخدام تقنیة الترذیذ الماكنتروني ذي التردد الرادیوي باستخدام أھداف من اوكسید الخارصین وتحت ضغط غاز االركون . وان الطاقة المستخدمة

و (300nm)) وبأسماك مختلفة PPcواط على قواعد بولیمیریة نوع ( 100للترذیذ ھي )(600nm وجد من خالل فحوصات حیود األشعة السینیة بأن أغشیة اوكسیدالخارصین .

,) 002وقمم ( 300nm للسمك 101)),( 002الرقیقة ذات تركیب متعدد التبلور وبقمم( وغرافیة السطح للمواد المرسبة باستخدام درست طب nm (600للسمك ((110) 102)(

. الحجم الحبیبي الذي تم الحصول علیھ یتراوح بین AFMمیكروسكوب القوى الذریة)19.61nm) و ((7.17nm ) 300)لألسماكnm و(600nm) على التوالي.

Abstract In this research , the structural and morphological properties of ZnO thin films prepared by reactive R.F. magnetron sputtering technique on (PPC) polymer substrates with different thicknesses 300 and 600 nm have been studied. The structure of ZnO thin films was tested with the X-Ray diffraction and it was formed to be a polycrystalline with recognized peaks oriented in ( 002) , ( 102) for thickness of 300nm and ( 002),(102),(110) for thickness of 600nm. The surface morphology of ZnO thin films have been studied by using atomic force microscope (AFM). The minimum grain size of the nanoparticles observed in the range of (7.17nm ) and (19.61 nm) for thicknesses of 300 and 600 nm respectively. 1. Introduction ZnO has the opportunity to be one of the most promising materials in many applications [1-5] due to its unique properties such as large excitation binding energy of 60 meV at room temperature [6, 7]. ZnO is an important II–VI semiconductor with a wide direct band gap of 3.37 eV (300 K) [8], excellent chemical and thermal stability [8] and high optical transparency in the visible and near-infrared region [9]. The

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resistivity values of ZnO films may be adjusted between 10-4 Ω cm and 1012 Ω cm by changing the annealing conditions and doping [10]. ZnO is electrically conductive and could be employed as transparent conducting electrodes for flat panel displays and solar cells. Due to its unique conducting mechanism based on oxygen vacancies [11]. For these features, ZnO can be used as solar cell windows [12], surface acoustic wave devices [13], light emitting diodes [14], gas sensors [15], piezoelectric transducers [16] and photovoltaic devices [17]. A wide variety of methods have been employed to prepare ZnO thin films including pulsed laser ablation, sol-gel technique, ion implantation technique, chemical vapour deposition, atomic layer deposition, chemical solution deposition, chemical spray pyrolysis and RF magnetron sputtering [18]. The aim of this work is to prepare ZnO thin films on PPC plastic utilizing RF magnetron sputtering in order to investigate the structural and optical properties concerning two different thicknesses. 2. Experimental:- ZnO thin films were prepared by RF magnetron sputtering system with a zinc oxide target of 99.99% purity on PPC polymer substrates with two thicknesses 300 and 600 nm. Firstly, the target was pre-sputtered in an argon atmosphere in order to remove oxide layer. The argon gas was introduced into the chamber through a flow controller with fine adjustments the sputtering was performed under Ar (99.999%) atmosphere supplied as working gas through mass-flow controller. The sputtering chamber was evacuated down to 5 × 10-5 mbar by the turbo molecular pump. PPC polymer was used as the substrates for thin films. Prior to deposition, the ppc substrates were cleaned by ethanol followed by distilled water rinse. The crystalline properties of the ZnO films were analyzed by an X-ray diffractometer using Cu Kα radiations (λ=0.15406 nm) and operating at an accelerating voltage of 40 kV and an emission current of 40 mA. For morphological investigations, AFM images were recorded using Nan scope IIIa scanning probe microscope controller in a tapping mode. 3. Results and Discussion 3.1. Film Structure X-Ray diffraction (XRD)

The X-Ray diffraction (XRD) analysis is conducted to determine the Phases and the grain size. The XRD patterns for the investigated ZnO samples prepared at room temperatures and constant deposition

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time as well as those deposited at different thickness (300nm and 600 nm) are shown in Fig. (1 a, b).

Fig. (1-a) XRD patterns of ZnO thin film of 300 nm thickness at room

temperature

Fig. (1-b) XRD patterns of ZnO thin film of 600 nm thickness at room temperature

It is observed from this figure that the XRD patterns of ZnO thin films of 300 nm and 600 nm thickness were polycrystalline with recognized peaks oriented in ( 002) , ( 102) for thickness of 300nm and ( 002),(102),(110) for thickness of 600nm. These results in agreement with the standard ZnO [XRD] X-ray diffraction data file [n 38-1479 JCPDS prevalent]. The mean crystallite size has been obtained with Scherer´s relation :

D = kλ / (βCosθ) ……………….. (1)

Where D is the crystallite size, k is a fixed number of 0.9, λ is the X-ray

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Wavelength, θ is the Bragg’s angle in degrees, and β is the full-width-at-half maximum (FWHM) of the chosen peak. The mean size of crystallization calculated using equation (1) for 300 nm and 600 nm thin films of ZnO were found to be (7.17) nm and(19.61) respectively.

Atomic Force Microscopy (AFM) Figures (2 and3) depict the surface morphology of the zinc oxide thin films analyzed by (AFM). The surface of the ZnO thin films as observed from the (AFM) micrograph confirms that the grains are uniformly distributed within the scanning area (520nm x 520 nm).An initial visual realization of the deposited films on PPC polymer substrate have shown that they are compact and have good adherence to the substrate. All the ZnO films exhibit a smooth surface with uniform grains. In these figures, the surface morphology reveals the nano-crystalline ZnO grains, which combine to make denser films significantly with the increased thickness. From the images, it was observed that the surfaces of the films exhibited a certain degree of roughness and the film came rougher when the thickness increases as shown in table (1).

Fig. (2): AFM images for ZnO thin films of thickness 300nm.

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Fig. (3): AFM images for ZnO thin films of thickness 600nm.

Table (1): surface roughness ,root mean square and grain size measurements for ZnO thin films

Film

Thickness (nm) Surface Roughness (nm)

RMS (nm) Grain Size (nm)

300 0.669 0.778 78.98

600 1.95 2.25 92.44

Table (2): comparison of grain sizes of ZnO thin films

Thickness (nm) AFM grain size (nm)

X-ray grain size (nm)

300 78.98 7.179 600 92.44 19.54 This results indicate that the growth of larger grains with increasing thickness. It is observed that the average grain size increases with increasing of thickness and the values of the average crystalline size change from (7.17-19.61nm) depending on film thickness . And the table (2) shows the comparison between the grain size of ZnO thin film calculated from AFM and XRD. It is clear from this table, that there are difference between the value of crystalline size measured by (AFM) and by (XRD) analysis. The

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former one measure the grain size directly which give the exact value while, the latter measure the grain size through Scherer’s equation which needs some corrections.

Conclusions

We have successfully prepared ZnO films by reactive R.F. magnetron sputtering method on PPC polymer substrates with different thicknesses. The resulting ZnO films were characterized by XRD measurement and AFM. We can conclude the flowing points from this work: 1-The ZnO nano films with thickness 300nm and 600nm were polycrystalline . 2- The grain size of ZnO films increased as the film thickness increased. Reference:

1. F. Zahedi, R.S. Dariani, Thin Solid Films 520 (2012) 2132. 2. S. K. Nandi, S. Chakraborty, M. K. Bera, C. K. Maiti, Bull.

Mater. Sci. 30 (2007) 247. 3. S. Venkatachalam, Y. Kanno, S. Velumani, Vacuum 84

(2010)1199. 4. H. Feng-Hao, W. Na-Fu, T. Yu-Zen, H. Mau-Phon, Solar Energy 86 (2012) 3146.

4. D. Ping, P. Xinhua, H. Jingyun, L, Bin, Z. Honghai, L. W. Chial, Y. Zhizhen, Mater. Lett. 71(2012) 18.

5. Ü. Özgür, D. Hofstetter, H. Morkoç, Proceedings of the IEEE 98 (2010)1255.

6. W. Yan, J. Tan, W. Zhang, X. Meng, T. Lei, C. Li, X. Sun, Mater. Lett. 87 (2012) 28.

7. N. Hongen, H. S. Hong, K. Kee-Kahb, K. J. Seong, K. Sunwook, S. E. Woo, K. E. Jung, Mater. Lett. 64 (2010)157.

8. P. Nunes, B. Fernandes, E. Fortunato, P. Vilarinho, R. Martins, Thin Solid Films 337 (1999) 176.

9. Z.B. Bahsi, A.Y. Oral, Opt. Mater. 29 (2007) 672. 10. D.D.O. Eya, A.J. Ekpunobi and C.E. Okeke, PJST. 6 (2005) 16. 11. W.J. Jeong, S.K. Kim, G.C. Park, Thin Solid Films 506–507

(2006) 180. 12. S.J. Pearson, D.P. Norton, K. Ip, Y.W. Heo, T. Steiner, Prog.

Mater. Sci. 50 (2005) 293. 13. P. K. Sang-Hee, L. Jeong-Ik, H. Chi-Sun, C. H. Yong, Jpn. J.

Appl. Phys. 44 ( 2005) L 242. 14. A. E. Valfolomeev, A. I. Volkov, A. V. Eryshkin, V. V.

Malyshev, A. S. Rasumov, S. S. Yakimov, Sens. Actuators B 727 (1992)16.

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15. T. Shiosaki, M. Adachi, A. Kawabata, Thin Solid Films 96 (1982) 129.

16. T. Pauporte, D. Lincot, Electrochim. Acta 45 (2000) 3345 17. A. V. Singh, M. Kumar, R. M. Mehra, A. Wakhar, A.Yoshida, J.

Indian Inst. Sci. 81(2001) 527.

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Preparing nanostructure SnO2 powder by using APCVD

Nagham T. Ali (1), Talib Z. T. AL-Mosawi (1) Ministry of science and technology, Baghdad,(Iraq)

[email protected], Abstract Nanoparticles of SnO2 have been prepared by using atmospheric pressure chemical vapor deposition (AP CVD )technique in gas-phase methods to obtain nanoparticles-based powders , using Stannous chloride (SnCl2.2H2O) as a starting precursor and substrate heat-treatment at (500°C) with O2 gas deposit on glass substrate. X-ray diffraction (XRD) study reveals tetragonal structure of SnO2 nanoparticles without any secondary phase. Scanning electron microscopy (SEM) image shows the spherical grain morphology of SnO2, particle size is found to be (26) nm, which is close to crystallite size (24 nm) from XRD using Scherrer equation..Optical transmittance was around (90%) with energy gap about (3.6) e.V .Atomic force microscopy was used for measuring the surface roughness and morphology، the roughness was about 2.92 nm . Key words: SnO2, thin films, APCVD…..

خالصةال�طر�قة الترسیب الكیماوي القصدیر النانوي في هذا البحث تم تحضیر شبه الموصل او�سید

، �الطور الغازي للحصول على مساحیق نانو�ة التر�یب �البخار �الضغط الجوي االعتیادي

على أساس من الزجاج �لور�د القصدیر المائي وتم الترسیب األولیة للتحضیر هيالمادة

ر�اعيحیود األشعة السینیة التر�یب ال أظهرت نتائج .) درجة مئو�ة500حرارة ( ةمسخن لدرج

صور المجهر االلكتروني الماسح فقد ، أماالو�سید القصدیر النانوي بدون اي طور ثانوي

) نانومتر والذي �قارب الحجم البلوري 26( ذات الحجم ي للحبیباتالشكل الكرو اوضحت

(%90) �انت �حدود البصر�ة . النفاذ�ة�استخدام معادلة شرر حسا�ه التي تم) نانومتر 24(

.استخدم مجهر القوى االلكترونیة لتحلیل طو�وغرافیا ) الكترون فولت3.6وفجوة الطاقة (

) نانو متر.2.92(التي كانت بحدود السطح خشونةو

133

mailto:[email protected],

mailto:[email protected],


1. Introduction

Tin oxide (SnO2) is one of the transparent conductive oxides (TCOs) where they are stable with good adherent to the substrate, hard mechanically and have large transmittance in visible region [1]. It is a very important wide-band-gap semiconductor (e.g., 3.6 eV at 300 K). Owing to its excellent optical and electrical properties, it has a broad range of high technology applications, such as optoelectronic devices, chemical sensors, solar cells, lithium batteries [2]. It is well known that the particle size and morphology of materials have a great influence on their properties. Therefore, synthesis of nanomaterials with well- controlled size and morphology may open up new opportunities for exploring a material’s chemical and physical properties. Since the discovery of SnO2 nanobelts in 2001 [3], research into SnO2 nanomaterials with a defined size and morphology has rapidly expanded. Various physical and chemical methods, such as thermal evaporation, chemical vapor deposition (CVD), metal–organic CVD, laser ablation and wet chemical synthesis have been employed to prepare SnO2 nanostructured materials in various geometrical morphologies, including SnO2 nanoparticles [4], nanorods [5,6], nanowires [7], nanotubes [8], nanobelts. SnO2 has been synthesized by different methods such as the sol–gel method [9], chemical vapor deposition (CVD) [10], magnetron sputtering [11] and hydrothermal treatment [12].

2. Material and method

Tin oxide thin film, which is prepared by homemade tube furnace APCVD, is glass substrate as shown in figure (1). SnCl2.2H2O was used as start material with O2 gas . the glass slides substrate were cleaned ultrasonically by TCE, acetone, ethanol followed by de-ionized water and dry with N2.the deposition temperature was 500 0C and gas flow rate was( 2 L/min) deposition time is about 30 min. X-Ray diffraction (CuKα) radiation with a wavelength λ =1.5418 Å at 2θ between 20°and 60°. Crystal structure study measured by Atomic force microscopy (SEM) and (AFM) was used for investigate the morphology and roughness of surface, optical properties was studied by UV-Visible spectroscopy.

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Fig. (1) APCVD tube furnace system;(1) N2 gas(2) flow meter (3) furnace (4) spiral hater (5) (13) heater electronic control with thermal sensor (K-type) (6) O2 gas (7) flow meter (8) circular heater (12) sensor with controller (9)byproduct treatment unit(10)(11) substrate and susceptor

Results& discussion 1-Structural properties by XRD The XRD pattern of the product is shown in Figure 1.The max. peak at 2θ values of 31.85°. Amatching of the observed and standard (hkl) planes confirmed that the product is of SnO2 having a tetragonal Structure.The average particle size (D) was estimated using the Scherrer equation :

D = 0.9λ / β cos where D is the crystallite size, λ is the X-ray wavelength, β is the full width at half maximum of the diffraction peak, and θ is the Bragg diffraction angle of the diffraction peaks. The average particle size was found to be 24 nm.

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Intensity

2θ Fig. (2) The XRD pattern of the SnO2 nano structure 2-Optical properties

SnO2 powder successfully deposited on to glass substrate and thin film were very transparent. The optical transmission of the samples is investigated in the range of 280 to 1100nm using UV-VIS spectrophotometer as shown in Fig.(3 ).The measurements are taken in the wavelength scanning mode for normal incidence Transmission spectra show 90% transmission in visible and near infrared region with energy gap was (3.6 e.V), see figure (4).

Fig. (3) optical transmittance against wave length for SnO2 thin films.

0

10

20

30

40

50

60

70

80

90

100

0 500 1000 1500

T%

wave length λ (nm)

Value(%T)

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Fig. (4) energy gap for SnO2 thin film

3- Surface topography properties

The study of surface morphology ,grain size of SnO2 powder deposited by chemical vapor deposition method has been carried out using atomic force microscopy(AFM) and SEM. In figure ( 5) we report the AFM image of SnO2 thin film,(a) 2D view (b) three dimension view 3D, it is clear that the deposited layer is very flat with roughness about (2.92nm). In order to have quantitative information about the sample topography we analyzed the surface heights histogram figure (6 ) .

(a)

0

100

200

300

400

500

600

0 1 2 3 4 5

(αhν

)2*1

0-22

hν(eV)

137


Fig. (5) AFM image of SnO2 thin film,(a) 2D view (b) three dimension view 3D.

Diameter(nm)<

Volume(%)

Cumulation(%)

Diameter(nm)<

Volume(%)

Cumulation(%)

Diameter(nm)<

Volume(%)

Cumulation(%)

35.00 50.00 55.00 60.00 65.00 70.00 75.00

1.15 1.15 1.15 8.05 4.60 3.45 4.60

1.15 2.30 3.45 11.49 16.09 19.54 24.14

80.00 85.00 90.00 95.00 100.00 105.00 110.00

6.90 4.60 9.20 2.30 11.49 4.60 6.90

31.03 35.63 44.83 47.13 58.62 63.22 70.11

115.00 120.00 125.00 130.00 135.00 140.00

5.75 5.75 8.05 3.45 5.75 1.15

75.86 81.61 89.66 93.10 98.85 100.00

Fig. (6 ) Histogram of the heights relative to scanned area of sample

b

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Figure (7) shows SEM image of prepared SnO2 nanoparticles. The spherical grain morphology of SnO2 nanoparticles is observed. The average grain size obtained from SEM is nearly 26.8 nm. It is slightly greater than crystallite size obtained from XRD analysis (24 nm) using Scherrer’s formula.

Fig. (7) Shows SEM image of prepared SnO2 nanoparticles

Conclusions

Tin oxide thin film have been successfully deposited at glass substrate by using APCVD method. Structural investigations using XRD reveal that the layers are composed of SnO2, grain size was (24nm ) measured by Scherrer equation. The average grain size obtained from SEM is nearly 26.8 nm Max. transmittance was 90% in a visible light spectrum, the average roughness of thin film surface is about 2.92 nm with spherical grain morphology References

1. Ferrere S, Zaban A, Gregg BA (1997) J Phys Chem B 101:4490. 2. Wang Y, Lee JY, Zeng HC (2005) Chem Mater 17:3899. 3. Wang Y, Zeng HC, Lee JY (2006) Adv Mater 18:645. 4. Comini E, Faglia G, Sberveglieri G, Pan ZW, Wang ZL (2012)

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Appl Phys Lett 81:1869. 5. Kolmakov A, Zhang YX, Cheng GS, Moskovits M (2003) Adv Mater 15:997. 6. Leite ER, Weber IT, Longo E, Varela JA (2015) Adv Mater 12:965. doi:10.1002/1521-4095(200006)12:13\965 7. Xu CK, Xu GD, Liu YK, Zhao XL, Wang GH (2002) Scr Mater 46:789. 8. Jiang LH, Sun GQ, Zhou ZH, Sun SG, Wang Q, Yan SY et al (2005) J Phys Chem B 109:8774. 9. R Rella; A Serra; P Siciliano. Sens. Actuators, 1997, B 44. 10 .SC Ray; MK Karanjai; D Dasgupta. Thin Solid Films, 2010, 307,

221. 11. NY Shishkin; IM Zharsky; VG Lugin. Sens. Actuators, 1998, B 48,

403. 12. NS Baik; G Sakai; N Miura. Sens. Actuators, 2013, B 63, 74.

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