the association of apett engineering magazine …...(r&d) in science and technologies have made...

APETT Engineering

Magazine June 2019

June 2016 Edition

June2019

Edition

The Association of

Professional Engineers of

Trinidad and Tobago

APETT’s Mission:

The Association of Professional Engi-neers of Trinidad and

Tobago is a learned society of profession-al engineers dedicat-

ed to the develop-ment of engineers and the engineering

profession. The asso-ciation promotes the highest standards of professional practice

and stimulates awareness of tech-nology and the role

of the engineer in society.

ISSUE 6

Dec 2018/ Jan 2019 Edition

June 2019 Edition

Issue 7

APETT Engineering Magazine June 2019

TABLE OF CONTENTS

DISCLAIMER: Statements made and information presented by contributors to this Magazine does not necessarily reflect the views

of APETT, and no responsibility can be assumed for them by APETT or its Executive Members and Editors.

Page 5

Page 8

Page 11

Page 17

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Page 26 Page 26 Page 29

Page 26

ARTICLE

What's the Difference Between a 'Proof of Concept' and a 'Prototype'? By: Arshad Mohammed

Make the Most Out of Your Internship

By: Brenton Chatoo

Design and Selection of Choke Valves Part II By: Avinash Babwah

Automated Identification of Vehicular Accidents from Acoustic Signals

Using Artificial Neural Networks By: Aaron D’Arbasie and Renique Murray

Bioplastics and Environmental Sustainability: Some Thoughts

By: Trishel Gokool

Assessing The Sensitivity Of The East Coast of Trinidad To Oil Spills By: Nyoka Sinanan

A Sustainable Solution for Red Mud in the Caribbean

By: Gino Hosein and Professor Indrajit Ray

KMA In-Plant Cold Recycling Technology In Road Construction and Rehabilitation In Trinidad ad Tobago

By: Laurence Bridgemohan

The “Human” case for Energy Efficiency in Trinidad and Tobago By: Sheena Gosine

Hand-Held NPK Sensor

By: Dillon Boodoo

Article References

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10

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37

40

45

53

Editor’s Message

Eng. Vicard Gibbings

Eng. Vicard Gibbings is a

Process Engineer with ap-

proximately 2 years’ experi-

ence in onshore and offshore

Oil & Gas and Petrochemical

Facilities. Experience ranges

from Conceptual Study,

Front End Engineering and

Design (FEED) through to

Detailed Engineering Design.

Experience includes: devel-

opment/review of Process

Engineering documents,

equ ipm ent/ va lve/ l ine/

restriction orifice sizing, de-

v e lo pm ent / upda t ing / a s -

building P&IDs; process safe-

ty support for PHAST conse-

quence modeling and subse-

quent firewater system de-

sign utilizing Pipenet. He is

also experience in Aspen

HYSYS software modeling a

range of process unit opera-

tions. In addition, he handles

project engineering duties if

required.

Apart from his normal day-

job, Vicard is a part-time

tutor, actively involved both

in IChemE TTMG and

APETT enjoys learning dif-

ferent things through online

courses.

GREETINGS! It has been my great pleasure working with the Chemical Division Team to present you the

very seventh edition of the APETT’s Bi-annual Engineering Magazine publication. Since I took over as the

Editor-in-Chief in January 2019, we have successfully made the smooth transition without too much disrup-

tion of the review flow, thanks to a few individuals who have helped me during this process. They are Julio

Bissessar (previous Editor-in Chief), Janelle Ramdahin, Therese Lee Chan, Nishawn Hanif. Sara Bernard

(Chemical Division Chair). Our former Editor-in-Chief, Julio Bissessar, continued behind the scenes to assist

whenever I needed help so that I could familiarize myself with the editorial procedure.

One of my goals as editor is dedicated to the rapid dissemination of high quality articles / papers on how

advances in STEM can help us meet the challenges of the 21st century, and to capitalize on the promises

ahead. We welcome contributions that can demonstrate near-term practical usefulness, particularly contri-

butions that take a multidisciplinary / convergent approach because many real world problems are complex

in nature.

In the past couple decades, we have witnessed significant issues in the real world. There are also the on-

going issues, such as energy, food due to rapid urbanization, management of resources, biological diseases

and environmental issues like the current debate about climate change. As engineers, scientists and re-

searchers, we aim to seek ways to harness the power of STEM to meet some of these real world challeng-

es, and to provide substance for making informed judgments on important matters.

Innovation and technological development will be essential for a global human benefits. In fact, historical

efforts in such sectors have already brought important results. Basic and applied research and development

(R&D) in science and technologies have made today. Innovation and R&D will be needed to continue im-

proving their efficiency, but greater efforts will be required to commercialize breakthroughs in all fields of

applications.

APETT provides an ideal forum for exchange of information on all of the above topics and more, in various

formats: full length and letter length research papers, survey papers, work-in-progress reports on promising

developments, case studies / best practice articles written by industry experts, and tutorials on up-and-

coming technological breakthroughs. Thus the APETT Engineering Magazine is a platform used to showcase

any breakthrough development or solutions to current and future problems and will be published two times

a year.

In STEM, as in most human endeavors, quality is more important than quantity. As stewards of APETT, the

editors have a fiduciary responsibility to the readership to ensure that only the very best STEM appears in

the journal. In a very real sense, the editors work for the readers; their charge is to select papers rigorous-

ly, publishing only truly new or novel information that constitutes an important conceptual advance in rela-

tion to existing knowledge, so that the readers’ time is spent wisely. In an increasingly busy and competitive

environment, the readers’ decision to look at our journal must be worth the effort.

The current “Professional Development” section alludes to the views of the real world. I am encouraging

different sections in the Engineering Magazine for the readership such as important events and STEM ad-

vances using a fresh, informal, conversational style. The content is miscellaneous: news of broad general

interest to the STEM community (including international news); major recent discoveries in the STEM field

as well as ground-breaking discoveries; highlights of the most exciting basic and translational science pre-

sented at STEM meetings; and commentaries by nominated STEM leaders. I wish to stress that this sec-

tion (like all sections of the journal) will not be used to push a political or ideological agenda. I believe that

journals / magazines ought to respect intellectual diversity, not only because of the obvious reason that it is

fair but also because exposure to different ideas is enriching. At APETT, we will not push political views or

ideologies of any kind; instead, we will strive to be inclusive, to respect diversity of opinions, and to the

extent possible and present all sides of an issue fairly.

Finally, we wish to encourage more contributions from the STEM community to ensure a continued success

of the journal / magazine. Authors, reviewers and guest editors are always welcome. We also welcome

comments and suggestions that could improve the quality of the journal.

Thank you and I hope that this article is enjoyable and informative!

Message from APETT’s President

I was a member of the Executive Council that made the decision to pub-

lish the APETT Engineering Magazine. As I recall, the Chemical Division had successfully published a magazine focused on their specific discipline.

The feedback from that publication was extremely positive.

A proposal was then put forward for the magazine to be made open to all the remaining divisions. I am pleased with the success of the magazine to

date as it continued to grow from strength to strength.

This biannual publication has proven to be a significant mechanism utilised by the association in its efforts to fulfil its mission to stimulate “awareness

of technology and the role of the engineer in society.”

We are truly thankful to our contributing writers who have provided in-

teresting articles based on their research and experiences in the field. It is

also noteworthy to mention the number of young engineers who have

provided articles for the magazine. It is my hope that their articles not

only serve to inform you, but also to inspire more of us to submit articles

for consideration.

I take this opportunity to thank our former Magazine Editor, Eng. Julio

Bissessar for his contribution to the magazine. I have no doubt that our

newly appointed editor Eng. Vicard Gibbings will continue in a similar

strain and build on the foundation set by Eng. Bissessar.

I would like to remind our members and supporter that APETT will be hosting our annual Honours and Awards function later this year. Infor-

mation about the event shall be disseminated to the membership in due

course.

We look forward to seeing you, our valued members, at this prestigious

event.

Eng. Vince Ramlochan possesses

over 18 years' experience as a prac-

tising Civil/Structural Engineer and

Project Manager. He is an Associate

of C.E.P. Limited, a Civil and Struc-

tural Design and Project Manage-

ment firm.

He has been involved in the civil and

structural design of several promi-

nent commercial and residential

projects as well as structural assess-

ments of existing structures. He has

also acted as Project Manager/

FIDIC Engineer for several promi-

nent construction projects.

Vince graduated from the University

of the West Indies (UWI) with a

BSc. (Hons) in Civil Engineering. He

is a Registered Engineer with the

Board of Engineering of Trinidad and

Tobago (BOETT) and a Member of

the Association of Professional Engi-

neers of Trinidad and Tobago, the

American Society of Civil Engineers

and the Project Management Insti-

tute. He is an Associate Member of

The Chartered Institute of Arbitra-

tors. Vince previously served on the

Executive Council of APETT as

Assistant-Secretary, Honorary Sec-

retary and Vice-President.

Vince is the current President of the

Association of Professional Engi-

neers of Trinidad and Tobago.

Page 4


What's the Difference Between a 'Proof

of Concept' and a 'Prototype'?

By: Arshad Mohammed, Graduate Research Assistant

When designing, I hear people using these terms, proof of concept and prototype, loosely when they are not

the same thing, thus I am writing this short and informal piece to explain the differences.

Proof of concept:

Proof of concept is usually done or built before any prototype. It is used to validate that a function of the envisioned

product can work. Let's say you are designing a new type of wind turbine to generate electricity to power homes in a

certain area, a proof of concept could just be using a rough shape or jury-rigging another small turbine, not necessarily

your own, to see if it is possible. Proof of concept could be held together by rubber bands and paperclips; it is your idea

broken down to its simplest and most fundamental form to see how well it holds up.

Problems arising in this stage is usually not design related but rather more to do with the practicality of your idea within

the context you would like to implement it. For example, you may find that during certain times of the day there is no

wind or that there are a lot of birds in the area that fly close to the turbine. Many times, issues arise due to the human

element; the community may not like the sight of the wind turbine in the area.

The information you gather here, problems arising, observations and success of certain functions can be used to refine

your idea before creating a prototype.

Prototype:

Types of prototypes include physical and non-physical. A physical prototype is the classical ‘prototype’ that you build and

put in place to test. Non-physical can be your Computer-Aided Design and Drafting (CAD) models and only exist in the

computer or even in mathematical equations. Do not underestimate the power of a CAD prototype though. You can

test pretty much all your working conditions in there such as wind speeds and directions or even how well your design

would hold up against a bird strike.

The design can be changed and retested in a matter of minutes before spending time and money on building the physical

version. There are two sub-types of physical and non-physical prototypes: prototype for form and prototype for function.

A prototype for form is one that does not work but is there to make sure the shape and size are good. For example, you

can use it to make sure your turbine fits in the required space or even use it to gauge how receptive people are to how

your design looks. A prototype for form does not have to work, it just needs to look the part.

On the other hand, a functional prototype does not need to look exactly like the finished product, it just needs to work.

In the case of the turbine, the blade shape is critical so that may remain the same, but mounting brackets and other hard-

ware need not look like the final intended product. It’s important to note that prototypes for form or function can fall

into both the physical and non-physical categories.

Bonus Round

Concept:

The concept is the idea that you came up with but have not developed as yet. This could just be a drawing scribbled hast-

ily on a napkin. It’s one of the first steps when designing new products.

Teams of designers are encouraged to come up with as many concepts as they can. During the concept generation phase

no concept is turned away, instead they all go through a process to narrow down the most appropriate. Innovative ideas

from concepts that would otherwise be discarded can be combined into other concepts.

It is for this reason at the early stages, no concept is rejected.

Pretotype:

No, I didn't misspell that. It is essentially ‘faking it til you make it’. It's a term coined by Alberto Savoia in 2009. I love it

for its ability to gather useful customer information before investing significant time and resources. The most famous

example is IBM having customers try out speech to text before the technology capability even existed. They put persons

in a room with a computer monitor and a microphone but no keyboard.

As the person spoke, the words would magically appear on the screen. These persons did not know that someone in

another room was listening and typing for them. It allowed IBM to discover problems such as how to delete something

once it was spoken.

This meant that as soon as the technology advanced to the point where this was possible, IBM had a massive head start

over their competitors who would have been finding those problems for the first time. Using a pretotype is a great way

to get funding for your idea; by showing potential investors what your product can do without actually having the prod-

uct. We see this used a lot in crowd funded products.

My advice when using this strategy is to ensure it’s made clear at some point that the product does not yet exist. I know

I’ve left out a lot of stuff so don’t take this to be a complete resource. I encourage you to look up more information

online if you are designing a product. Doing the proper steps builds a solid foundation and would enable you to have a

much clearer sense of the direction in which you want to take your idea.

Arshad Mohammed has been teaching

courses related to product design and product realization for the last five years and is cur-rently pursuing his PhD in manufacturing at the

University of the West Indies This, coupled with working with people for his design and 3D printing business have revealed many mis-

understandings of the field among persons looking to create their own inventions.


Make the Most Out of Your Internship

By: Brenton Chatoo, Junior Mechanical Engineer

Acknowledgments: I would like to extend a special thanks to Andy Newton, Kiran Rampat, Nicholas Burke, Adesh

Jaikaran and the entire staff of Nutrien Trinidad.

Congratulations! You’ve just been hired for an Internship at Nutrien. “You must be very excited to work alongside the

top professional engineers in your area of study”, were my first thoughts. On the 4th day of June, 2018, I started working

as an Intern attached to the Inspection Department located at Mediterranean Drive, Point Lisas where I worked closely

with Inspection Specialists and Reliability Specialists. To my mind I thought it to be a typical Internship with the usual du-

ties such as backlogging, filing and if I’m lucky enough maybe data entry and that’s what happened.

My very first task at Nutrien was to rearrange a library situated in the Drawing office which was shared with the Inspec-

tion office. The task was very tedious and cumbersome and I would have loved to do something else. Within the first

week I realized this internship was going to be different, not because I was receiving satisfactory work but because every-

one, and I stress, everyone was always busy. This was slightly intimidating as I really wanted to give my best impression.

This high level of productivity kept me motivated and really impacted my work ethic which made me appreciate all the

tedious work given to me and it made me realize one thing. As an intern, the work is not as exciting for the most but

someone has to do it. I could not imagine any of the other employees sparing 10 minutes to attempt the tasks given to

me. At this point I drew a line between Intern jobs vs Professional jobs. As an intern you are supposed to do these jobs

so that the professionals’ jobs can be easier and always remember, someone has to do it. It helps build character and you

will have a greater appreciation for all the mechanisms involved at Nutrien. The job has to be done.

Throughout the course of my Internship, I saw it as the beginning of my career and expected to be afforded upward mo-

bility within the structures and corporate ladder of Nutrien. I saw myself having a realistic prospect of becoming perma-

nent, achieving promotions and opportunities for advancement within my Department. At this point, I tried my best to

get the work done as quick and efficient as possible. Your attitude and approach to tasks as an intern should align itself

with maximizing productivity and efficiency while understanding that the reward will often times be another opportunity

to prove yourself, to yourself and to your company. Maintain an open mind to assisting in different disciplines as this pro-

ject a helpful spirit onto your employers and it will be commended. So interns, get as involved as possible.

Up to this point, you should be very busy. Soon enough, you’ll be given some unreasonable tasks to get done that you

may not think you’re ready for. For example, I was asked to present on a new program developed by the IT Department

that they would use to manage data from the Inspection Department. This program was very new and only 3 Interns

were trained to use it, including me. When I was asked to present initially, I assumed I had a day or two to prepare how-

ever I had a humbling 10 minutes. What was even more humbling was the audience I had to present to, which included

many managers and superintendents. I could have rejected it but where would that have gotten me?

As an intern, I really had nothing to lose so I weighed my options and decided to leave my comfort zone and proceed

with the presentation. The first five minutes did not go as horrible as I thought it would go but midway the System Ana-

lyst was able to come in and take over the presentation. She then left me to deal with the questions. Even though I

couldn’t present to everyone, I was able to have a conversation afterwards with a room full of professionals and their

concerns on the program. Interns, do not stay in your comfort zone. It may sound cliché but don’t let the fear of failure

hold you back. Weeks after, I was given my first engineering project alongside another intern and only since then I’ve

truly appreciated how crucial that very same library we sorted as interns, is to the staff of Nutrien.

I was fortunate to have good timing, great mentors, supervisors and bosses who were key in my development as an engi-

neer. Sometimes we may take for granted the people we work with and not realize that they may be one of the very

best in their area of study, so always show them the respect they deserve. If they are difficult to work with or even strict,

embrace it because it just means they have high standards and expectations. Also keep in mind to be very professional

and do not get involved in office politics at all. Create clear boundaries between your personal and professional life.

In conclusion, take your job seriously and have it done to the best of your ability, always remember the job has to be

done, no two ways about it. By doing your job, the professionals’ job becomes easier allowing them to get the more criti-

cal jobs done. Also, I advise to get involved as much as you possibly can, never shy away from stepping outside your com-

fort zone. You’ll only know you can’t do something until you do it and remember to stay professional. Most importantly

stay humble and respectful to the people you work with on every level. An internship does not always promise a job but

give it its best chance to be. It provides an opportunity for growth, learning and advancement in your career goals. Make

the most of it.

Brenton Chatoo is currently a Junior Mechani-cal Engineer stationed at Nutrien Trinidad with

growing experience in the Oil and Gas Industry. He provides specialized engineering support for the Reliability and Inspection of plant assets to

ultimately aid in production of Ammonia and Urea. Brenton aspires to become a well-accomplished Reliability Engineer and one of the

best in his field. He has special interests in Metal-lurgy and Plant Processes.


Design and Selection of Choke Valves

Part 1I

By: Avinash Babwah, Process Engineer

1.0 Results

Case 1

Table 1.0: Application data for datasheet 1 and simulat-

ed results

Figure 1.0: Cv vs Percentage Opening of Choke valve, Lin-

ear 1.5'' Trim

Case 1I

Table 2.0 : Application data for datasheet 2 and simulated

result

Flow Characteristic curves of choke valves were generated

based from the model of NOV’s choke valve selected and

information from the data sheets. The NOV Varco MPC60S

1.50’’ Linear and MPC60S 2.5’’ equal percentage were both

well suited per datasheets 1 and 2 respectively with the life

of the well in mind. The required Cv falls well within the

designed sizing ranges of 40-75% of choke valves. NOV’s

MPC60S model nominal designation body size is 6’’ which

allows various trim sizes to be used ranging from: 1’’, 1.50’’,

2.00’’, 2.50’’, 3.00’’, 3.50’’, 4.50’’ and 5.00’’. The

MPC60S model was selected for its 6’’ nominal body size in

keeping with the specified 6’’ ANSI 2500 outlet flanges as

per both datasheets/applications. What required the use of

discretion, was the selection of trim size or orifice size. The

linear curve, figure 6 shows two cases, the minimum and

maximum Cv for the 1.5’’ trim. Using a trim/orifice size of

1.5’’, as the choke is initially opened to 20%, there is no

flow with a constant Cv of approximately 0.

Figure 2.0: Cv vs Percentage Opening of Choke valve,

Equal % 2.5'' Trim

This is considered a dead band due to the plug travel not

exposing the flow area until 12.5% and greater. Looking

further, from 20-89% there is a sharp but linear increase in

Cv as the choke is opened further to maximum of 50. This

is because the orifice pattern is similar throughout the en-

tire trim with travel. With the desired gas flow of 30mmscf/

day, associated condensate of 60 bbl/day and produced wa-

ter of 15bbl/day, requires an average Cv of 16.5 and

42.0% opening of the MPC60S 1.5’’choke generating a

maximum exit velocity of 48.09ft/s and predicted noise

less than 85dBA. The exit velocity is well below the sonic

velocity or mach 1 and industrial standard of 85dBA which

decreases the risk of cavitation and erosion. ChokeSizer

does not show the predicted noise levels less than 85dBA

but do when greater than 85 dBA. This is a clear indica-

tion that vibration and cavitation would not occur within

this 1.5’’ choke trim and choke body.

For this application the choke is operating less than half its

capacity which gives the flexibility of opening the choke

further to provide a greater flow area when well pressures

have decreased below initial production. This would help

maintain production levels of at least 30MMSCF/day or

more if desired. Hence, the choke valve was sized using

the MPC60S 1.5’’ trim keeping in mind the life of the well.

Application two, only one case was provided with a gas

flow rate of 45.00mmscf/day, associated condensate of

90.00bbl/day and produced water of 22.50bbl/day with a

pressure drop of 225.00psig. The flow requirements for

this application is greater than application one by 15mm-

scf/day of gas, 7.5bbl/day of water and 30bbl/day of con-

densate. Thus, from simulations the best design to achieve

these flow is the MPC60S 2.5’’ equal percentage trim with

an exit velocity of 72.13ft/sec and predicted noise of less

than 85dBA (0 dBA as per results). This is a clear indica-

tion that vibration and cavitation would not occur.

The MPC60S 2.5’’ equal percentage trim design, a Cv of

49.87 and 48.06% travel is required to produce 45mmscf/

day and its associates. A maximum Cv of 150 is achievable

with approximately 96% of travel allowing the flexibility to

open the choke valve more later in the well life to main-

tain gas production. This is the ideal choke valve trim

bearing the well life in mind. Interpretation of the flow

with percentage travel (figure 6) shows a relatively linear

pattern except the lower and upper boundaries of the

flow curve. This is due to the flow geometry being smaller

at these regions of the trim (smaller slots), where the slots

size increased and remains uniform in the linear region.

The dead band at the bottom of curve is due to the plug

not exposing the flow area to fluid flow while the top dead

band occurs since the total flow area is already exposed.

This choke would produce negligible/no flow when

opened up to 11.9%. Opening the valve further above

21%, the Cv increases gradually up to 26% choke travel, as

it is opened further, and a larger flow area is exposed and

more fluid flows, there is then a faster increase between

26% and 90%. The fastest rate of production in terms of %

travel would be seen in the range of 30% and 90% where

the maximum Cv is attained and entire orifice area is ex-

posed to flow. The plug exposes all of the available holes

to flow at 96% open and further opening won’t affect any

increase in production.

For both application, the choke trims would be construct-

ed from tungsten carbide steel because of its erosive re-

sistant properties to cater for any solid or sand produc-

tion while the body and bonnet would be made of AISI

4130 low alloy steel. Typically the AISI 4130 low alloy

steel is cheaper than the tungsten carbide steel creating a

more economically affordable valve.

The choke would be automated with a stepping actuator,

National Oilwell Varco (NOV) VBS100. This would be

operated via instrument air signal ranging from 80-120psig

to the actuator via solenoid valves and controlled via the

control room. The stepper choke control would be used

such that when the step count is increased or decreased

the choke valve opens or closes respectively. Each pulse

signal (instrument air) to the internal piston, moves the

pawl in contact with the drive spool and produces a 36o

rotation of the stem coupling. This gives the operator ac-

curate controllability of the flow and prevention of instan-

taneous increases. The valve is fail-safe last position mean-

ing that if the solenoids fails to fire the choke would re-

main in the same position unless manually override. The

chokes can be override manually via an external hex nut

coupled to the drive spool and choke valve stem.

The travel of the choke would be monitored via a Top-

worx DXP position transmitter and be relayed to the con-

trol room for monitoring. It consists of a 5KΩ and a 4-

20mA transmitter for remote feedback of the choke posi-

tion. This allows the operator to determine the theoreti-

cal flow out of the choke compared to actual. If the flow

is more than the theoretical then it can be possible that

the choke plug is eroded and exposing greater area to the

flow area.

Thus, the well needs to be shut in and choke valve removed

for inspection and repairs.

2.0 Conclusion

Chokes valves were designed and selected based on choke

valve datasheets utilizing the service conditions (Fluid flow

rates and properties, ΔP) and actuator parameters into Na-

tional Oilwell Varco Chokesizer! Program. Flow characteris-

tic curves (Cv) were developed for two cases or wells in

Trinidad’s East Coast where the Cv’s were less than half the

total percentage of choke opening. This provides the end

user with the ability to produce more gas without any design

modifications to the choke. This would save the end user

money and downtime long term in future modifications and

expansion.

The trims of both valves would be constructed from tung-

sten carbide steel due to its erosive resistant properties

whereas the valve body and trim would be made of AISI

4130 low alloy steel. Both cases were of a typical choke

valve, where the pressure drop was relatively small, noise

and vibration were within permissible limits. Cases where

the pressure drop i.e. differential pressures between the

inlet and outlet of the choke valve is greater than 1500psig

should be investigated for future work. Typically with high

pressure drops in choke valve, noise, vibration and cavitation

are usually associated and unwanted. This causes severe

valve body wall loss and pipe/material fatigue in downstream

piping, posing a serious process safety hazard. The industry

have moved to choke valve having multistage trims in an ef-

fort in reducing noise, vibration, and cavitation.

Multistage trims can be recommended to be used in lieu of

the existing single stage trims on both choke valves if cavita-

tion and vibration were to occur. Additionally, the trim wear

monitor port should be tied into an alarm system whether

audible or electronic to alert operators or tied to an emer-

gency shut down system to prevent damage to seat body.

Sand production should also be monitored and special atten-

tion and precautions should be paid to choke valves where

there are abnormal increases of sand. As with any piece of

equipment, routine maintenance programmes should be de-

veloped and executed to maintain equipment integrity and

functionality.

Figure 3.0: Choke Valve Datasheet 1

Figure 4.0: Choke Valve Datasheet 1I

Avinash Babwah, a National Scholar, having placed 8th in Environmental Studies at the CAPE 2010 Examinations, and graduated in 2015 with a BSc. In

Chemical and Process Engineering from the University of West Indies.

Avinash is currently employed at Process Components Limited as a Process Engineer in the Projects Department, focusing on Technical Sales and Services,

Project Management and After Market Support. Throughout his tenure at ProCom, Avinash has worked with a number of Up-

stream Operators and has been involved in major Brownfield Projects with companies such as British Petroleum Trinidad & Tobago, Shell Trinidad and Tobago and EOG Resources. His exposure to the oil and gas industry and his

yearning for knowledge has led him to excel in his career and to further his studies with the pursuit of a MSc. In Petroleum Engineering.

Avinash has a passion for the game of cricket and is known for not missing a match. He appre-

ciates a great movie or TV-Show, and has a love for travelling, exploring beaches, hikes and snorkeling.

Abstract

As a consequence of its critical impact upon societies, the

occurrence of vehicular traffic accidents is a globally studied

phenomenon. Much effort has been directed towards the

understanding and identification of causal factors, with the

intention of minimising the occurrence. In a related area, the

development of methods for the identification and classifica-

tion of vehicles has also received necessary attention. How-

ever, little work has been done on the development of

methods for the identification of motor vehicle accident

occurrences. Thus, this work sought to develop an automat-

ed system for the identification of motor vehicular acci-

dents. It utilises an artificial neural network approach to

estimate the probability of occurrence, based on recorded

acoustic signals. More specifically, it first characterises acci-

dent acoustic signals by 9 selected signal features, in both

the time and frequency domains. It then develops a dual

layer artificial neural network, which accepts as its input the

9 characterising signal features and as its output calculates

the probability of occurrence. The system was built and

tested in the MATLAB environment, utilising 22 sample sig-

nals in the design phase and a further 53 for testing. An eval-

uation of the system found it have an accuracy of 86% and a

precision of 76%, with a 100% identification of actual acci-

dents. Additionally, it was found that the system prioritises

the time domain signal features over those of the frequency

domain, in the identification process. These results validate

the structure of the system used and demonstrate its poten-

tial for real-world applications.

1.0 Introduction

Road safety is a global concern. The World Health Organi-

sation reports that there were 1.25 million road traffic

deaths in 2013 alone (WHO, 2017). The impact of this phe-

nomenon is far reaching and many countries have been ag-

gressively seeking to counteract it. Accordingly, much effort

has been directed into the research of various aspects of

accident occurrences. Many researchers have investigated

the causal factors in the occurrence of accidents (de Ona et

al., 2013; Dadashova et al., 2016; Mujalli and de Ona, 2011).

The primary goal in most of these instances has been to

understand what causes accidents, with the intention of

minimising their occurrence. Similarly, other researchers

have sought to develop methods for identifying road con-

flicts (Cafiso et al., 2017) or for assessing the likelihood of

an accident occurrence in a particular location (Li et al.,

2017). Further, some investigators have developed methods

for reconstructing accidents, based on data gathered from

the scene of an accident (Li et al., 2017; Evtiukov et al.,

2017). Yet further, some researchers have developed meth-

ods for the determination of the level of injury of a vehicle's

occupants, upon the occurrence of an accident (Kononen et

al., 2011; Delen et al., 2006).

A related field of study of particular interest, is the detec-

tion and identification of motor vehicles. Several researchers

have used vibration and/or acoustic data, coupled with signal

processing techniques, to develop effective vehicle recogni-

tion and detection methods. Wu et al. conducted significant

work in this area and were among the first to utilise a fre-

quency spectrum principal component analysis approach for

vehicle sound recognition (Wu et al., 1999). George et al.

(2013 a) also used vehicle sound signals to detect and classi-

fy vehicle types in an Indian context. They developed an

algorithm that processed the acoustic data and allowed for

vehicle detection, then used a neural network for classifica-

tion. George et al. (2013 b) have advocated for the use of

wavelet analyses in their detection and classification tech-

niques. Yet in another case, Ozgunduz and Turkmen (2010)

designed a vehicular classification system using a Mel fre-

quency Cepstral coefficient algorithm and extracted features

of the acoustic data which was then reduced by using a vec-

tor quantisation algorithm.

Despite these efforts, little work has been done on the de-

velopment of methods for identifying the actual occurrence

of accidents. Currently, accident identification primarily re-

lies on visual recognition. In many cases, this is based on

reports by person(s) involved in the accident or by bystand-

ers. In others, the analysis of real time traffic camera data

allows for accident identification. However, this is limited by

several environmental factors such as the state of the vehi-

cle's occupants, the presence of bystanders and their willing-

ness

Automated Identification of Vehicular Accidents from

Acoustic Signals Using Artificial Neural Networks

By: Aaron D’Arbasie and Renique Murray

to assist, lighting conditions and the level of monitoring of

traffic camera data. In-vehicle collision systems provide an

effective alternative. However, this too is limited by the

make and model of the vehicles involved and the level of

support system architecture in a particular location.

In light of this, this work presents an automated approach

for the identification of vehicular accidents. It utilises a com-

bination of an artificial neural network and some selected

signal processing techniques, to identify the occurrence of

an accident based on acoustic signal data. Such an approach

can be incorporated into existing traffic management sys-

tems or form the basis for a standalone system. In so doing,

it can facilitate faster response times to critical accidents

and increase the chances of saving an injured occupant's life.

2.0 System Design

2.1 General Approach

By virtue of the phenomenon’s nature, there are a number

of attributes that can be considered and examined in seeking

to detect the occurrence of an accident. Some of these in-

clude visual imagery, vibration data, scents/odors and

sounds. However, not all of these features are as easily

quantified and recorded, and the level and type of infor-

mation provided by each feature varies significantly. Not-

withstanding this, the work done on vehicle detection meth-

ods suggests that acoustic data samples provide a wealth of

information that can be used for accident identification, if

processed correctly. In keeping with this, this work sought

to use acoustic sample data as the primary data source for a

proposed identification system.

Figure 1 shows a typical acoustic sample recorded for an

accident. It can be seen that the accident is defined by a dis-

tinct rise in the amplitude of the acoustic signal and for a

short period of time. This pattern repeats itself for most of

the acoustic samples examined. Given the repetitive nature

of the pattern, the use of an artificial neural network was

considered to be a feasible approach for identifying its oc-

currence within a recorded signal.

2.2 Identification of Signal Features for Characterisation

The efficacy of neural networks in pattern matching and

identification, has been steadily increasing over the past few

years. Two key contributing factors have been the increas-

ing computational power of computing systems and the

growing access to more detailed data sets. However, de-

spite this increase in computational power, there are still

some evident limitations, i.e., the processing of large data

sets by a neural network does present a challenge for most

standard computers. For instance, the car accident acoustic

sample of Figure 1, which is 2.5 seconds long and sampled at

44.1 kHz, contains 110,250 data points. Attempts to directly

utilise this sample in an artificial neural network, have prov-

en to be memory-intensive for a current, standard desktop

computer. Accordingly, an alternative approach to utilising

the acoustic data in an artificial neural network had to be

developed.

Figure 1.0: Sample of accident acoustic data signal Ampli-

tude versus Time

As an alternative, it was considered that a signal can be rep-

resented in both the time and frequency domains. In keeping

with this, either presentation of the signal presents unique

aspects of the data. Accordingly, the signal can be character-

ised by the features of either representation, or a combina-

tion of both. Thus, the features in both the time domain and

the frequency domain are identified, such that these features

are influenced by the occurrence of an accident. Then, this

subset can be used to identify the presence of an accident.

Key to this proposition is that the features must vary specif-

ically with the occurrence of an accident.

In so doing, they provide both a basis set for representing

the accident signal and for assessing the presence of an acci-

dent within a wider signal. However, it is unclear which of

the many signal characteristics in the time or frequency do-

main would be critical in assessing the occurrence of an ac-

cident. In light of this, a number of well-known signal fea-

tures and characteristics were examined, to determine their

level of influence in accident identification from acoustic

sample data. Table 1 gives the list of the features assessed in

this work.

3.0 Data Sets and Data Acquisition

For the purposes of training and evaluation of the system,

acoustic samples of various accidents were required. How-

ever, due to limited funding availability, the recreation and/

or simulation of real time vehicular accidents were not feasi-

ble in this work. Alternatively, existing accident data sets

were used. These comprised of data obtained from various

crash intuitions namely Insurance Institute for Highway Safe-

ty (IIHS) and European New Car Assessment Programme

(Euro Ncap). Both institutions conduct crash testing on a

wide range of vehicles and various types of collisions (e.g.,

head-on, and small overlap). The sampling frequency for

audio capture used in these data sets, was given as 44100

Hz for both institutions. The distance from the microphone

to the point of impact was not given; however, it was

known to vary for both. The acoustic greater accuracy of

representation. The vehicle type and accident details for the

various samples examined, are presented in Table 2

As opposed to one type, various types of collisions were

used to ensure variability in the accident features examined.

The aim of this approach was to increase the system's likeli-

hood of identifying a random accident. A total of 45 vehicu-

lar accident samples was used in the development of the

system.

Additionally, simulated accident data was obtained from a

test rig that was setup for the purposes of the work. The

test rig consisted of a weighted automobile front bumper,

suspended in mid-air by a pulley system. The bumper was

lifted to a height of 12 feet and then allowed to fall and

strike a metal sheet, which was fitted with an accelerome-

ter.

Table 1.0: Acoustic signal features examined to determine

effectiveness in accident identification

Table 2.0: Types of vehicles for which data was acquired

A microphone was positioned 10 feet away from the drop

site, to record the acoustic data. The data was recorded at a

sampling rate of 44,100 Hz. A picture of the setup is shown

in Figure 2. Some of the amples recorded here were used in

the identification of the set of key signal features. Addition-

ally, acoustic samples taken of a jackhammer in operation

and of random noises were also recorded for use in as-

sessing key signal features.

Figure 2.0: Image of simulated accident testing setup

4.0 Results and Discussion

4.1 Identification of Key Signal Parameters

The signal features presented in Table 1 were assessed for

all of the test signals previously mentioned. Various plots

were made to examine the performance of each character-

istic. The results obtained here were used to determine

which characteristics were most suitable for classification of

an accident. Figure 3 shows the plot of normalised mean

signal amplitude against signal variance.

Figure 3.0: Pot of mean amplitude vs. variance

It can be observed from the figure that an accident is easily

characterised by the variance of the amplitude time plot.

The variance of the accident signals is found to be lower and

exhibits less variability than the other signals examined. An

examination of the normalised, mean amplitude shows that

for an accident signal, the values are much lower than the

other signals considered. This is due to the fact that acci-

dent signals contain localised points of very high amplitude,

with the remaining portion of the signal having significantly

lower values. On the contrary, noise signals generally do not

have notable localised peaks and consequently their normal-

ised means are higher. Accordingly, both features are suita-

ble for characterisation.

Figure 4 illustrates the changes in the fundamental frequency

and the zero-crossing rate of the signal. From the figure, it is

evident that the values of the zerocrossing rate are much

higher for both sets of accident signals, as compared to oth-

er signals considered. Accordingly, this is a suitable signal

feature for characterisation. Conversely, the fundamental

frequency demonstrates a high degree of variation and does

not show any specific relationship for the signals considered.

In keeping with this, the fundamental frequency serves as a

poor characteristic and its use would lower the efficacy of

the system.

Figure 4.0: Plot of zero crossing rate vs. Fundamental fre-

quency

An examination of the bandwidth values in Figure 5, shows

that it is difficult to differentiate an accident signal from

those of the other signals considered. Accident signals have

wider bandwidth ranges than the other signals, making char-

acterisation difficult.

Conversely, accident signals can clearly be distinguished by

the spectral crest values. The spectral crest values for both

sets of accident signals are visibly lower than the other sig-

nals considered. Accordingly, the spectral crest was selected

as a feature for characterisation, while bandwidth was not.

An examination of Figure 6 shows no clear relationship or

correlation between the occurrence of an accident and the

maximum energy or the energy flux. These two signal fea-

tures are dispersed through a large area, and hence at-

tempts to use them for accident characterisation may intro-

duce some error into the system.

Consequently, both parameters were not included in the

final subset used to develop the system.

Figure 5.0: Plot of bandwidth vs spectral crest

Figure 6.0: Plot of energy flux vs. Maximum energy

Figure 7 displays the frequency envelopes of the accident

and noise signals tested. The signals have been converted

into the frequency domain using a fast Fourier transform.

An analysis of the graph shows a distinct difference between

the noise signal (blue) and the accident data (black). It can

be seen that the frequencies present within the accident

signals are more stochastic as compared to the noise signals.

Additionally, the amplitudes of the frequencies that are pre-

sent in the accident signals are larger than those of the

noise. Accordingly, the frequency envelope was chosen as a

feature for accident characterisation.

4.2 Network Development and Architecture

Based on the previous analysis, 9 signal features were identi-

fied for the characterisation of accident signals.

The features include both time domain and frequency do-

main identifiers. The time domain features selected were

the energy flux, mean amplitude, power, zero crossing rate

and variance; whereas the frequency domain features in-

clude frequency envelope, bandwidth,

Figure 7.0: Frequency envelope of various acoustic events

spectral crest and variance. In so doing, this allows for the

reduction of an accident signal having 110,250 points to 9

characteristics. Figure 8 shows the sequence of computa-

tional steps within the final system.

The development and subsequent analysis of the network’s

performance was done using MATLAB 2015. This process

entailed two primary decisions: a determination of the num-

ber of layers in the network and a determination of the

number of neurons required for accurate functionality. The

previous analysis indicated that the characteristics of an acci-

dent signal are not linearly separable. In keeping with this, a

multilayer approach was considered to be more suitable.

More specifically, a dual layer configuration was implement-

ed, with a hidden layer containing a linear function and an

output layer.

Figure 9 shows the final architecture of the neural network.

The batch training method was selected as the basis for

training the network, using a sample set of 22 signals. This

was implemented with randomly determined batches, using

a gradient descent algorithm via the MATLAB interface. This

Figure 8.0: Final system architecture

approach minimises the loss function as a means of adjust-

ing function weights and improving the network perfor-

mance. MATLAB subsequently validates the network with a

subset of samples.

Figure 9.0: Final architecture of the neural network

The determination of the most suitable number of neurons

was effected via the pruning approach. The proposed se-

quence of computational steps in Figure 8 was implemented

using a test network having 11 neurons in the hidden layer.

This test network was trained and validated as previously

discussed. Subsequently, its performance was assessed via

the examination of key network characteristics. More spe-

cifically, the root mean squared error (R2 value) relative to a

set target value was calculated for the test network, which

was indicative of its ability to observe trends.

Nine other test networks were subsequently developed,

using a different number of neurons in the hidden layer,

ranging from 10 to 2 neurons. Each test network was

trained, validated and assessed in a manner that was identi-

cal to that of the 11-neuron network. Three of the test net-

works were found to have R2 values of 0.999, indicating the

ability to accurately differentiate between a car accident

signal and the other test samples.

Using Ockham’s razor principle, four neurons were selected

as the most suitable number of neurons to be used in the

network. Accordingly, the final system architecture consist-

ed of 2 layers with four neurons in the hidden layer. This

system is such that 109 points are inputted based on the 9

characterisation features and a probability value is output-

ted.

4.3 System Performance

The system was tested using a number of new data sets, i.e.,

signals that had not previously been used in the develop-

ment and training of the system. These data sets consisted

of 16 car accidents signals obtained from the Insurance Insti-

tute of Highway Safety (IIHS), 7 simulated accident signals,

12 noise signals, 9 sample signals of impact strikes on differ-

ent materials, and 9 other sample signals of noises likely to

be recorded on the roadway (e.g., emergency sirens and

jackhammering). Of the 53 tests on the system conducted,

Figure 10 presents the results of 36 outputs of the network.

Table 3 presents a confusion matrix for the predictions

made by the system.

Figure 10.0: Results of Classifications System Output for

Acoustic Data

Table 3.0: Confusion matrix for predictions made by sys-

tem

In keeping with Table 3, the following performance criteria

can be evaluated: Accuracy = (true positive + true negative)/

total = 86%, True positive rate = True positive/ Actual posi-

tive = 100%, False positive rate = False positive/ Actual no =

30.4%, Precision = True positive/ predicted yes (when it

predicts yes, how often is it correct) = 76%.

4.4 System Behaviour

In examining the system, some key relationships and behav-

ioural trends were identified. One of these concerns the

issue of the incorrect classification of the impact strike sig-

nals. It was noticed that impact strike signals where a high

force was used, had a higher chance of being classified as an

accident. This false positive classification occurred both with

strikes to steel and polyethylene materials.

Although the natural frequencies of both steel and polyeth-

ylene of similar masses contrast greatly, both were still clas-

sified as a car accident. This suggests that the neural net-

work gives precedence to characteristics in the time do-

main, as opposed to those in the frequency domain. This is

likely a consequence of the fact that the features in the time

domain display a greater correlation with the occurrence of

a car accident, than those in the frequency domain.

A second key behavioural trend concerns the nature of the

probability values obtained. The outputs for the tests con-

ducted showed a range of values between 0.7 -1.0, to pre-

dict the occurrence of an accident.

Conversely, probabilities of 0 - 0.21 were found in cases

where the system suggested that an accident did not occur.

These ranges of probability values allowed for clear inter-

pretations to be made on whether or not an accident did

occur. This result was a consequence of the sigmoid func-

tion in the hidden layer. Its insertion reduces the probability

of having instances where the neural network predicts a

50% chance of the occurrence of a car accident. These re-

sults serve to validate the structure of the system used.

5.0 Conclusion

This paper presented the work done on the design of an

automated system for identifying vehicular accidents, using

acoustic signal data and utilising an artificial neural network

approach. The system was based upon the identification of

key signal features that were used to characterise an acci-

dent acoustic signal. A total of nine signal features was iden-

tified with five being time domain features and four of the

frequency domain.

These features allowed for large data signals to be repre-

sented by a much smaller data set; in so doing significantly

decreasing the computing requirements of the system. The

system was designed and tested using MATLAB. In designing

and training the system, 22 signals were used. These signals

consisted of actual accident recordings, simulated accident

data and other recorded acoustic data. The system was sub-

sequently tested using 53 additional signals that were not

used in the design phase.

An evaluation of the system's performance found that it had

an accuracy of 86% and a precision of 76%, with a 100%

identification of actual accidents. Testing also served to

identify that the system prioritises the time domain signal

features, due to a greater correlation between changes in

these values and the occurrence of an accident.

With correct incorporation into a wider traffic management

and/or emergency system, the approach presented here has

the potential to significantly increase the likelihood of identi-

fying vehicular accidents. In so doing, it can increase the

response time of emergency personnel and increase the

potential for saving lives.

Renique Murray is a

trained Mechanical Engi-neer and has been lectur-ing, managing projects and conducting postgrad-

uate research in various aspects of the field over the past fourteen years.

He holds both a BSc. and an MPhil degree in Me-chanical Engineering, with

the latter focusing on vibration analysis of pow-

er generation rotating machines. He also holds a PhD. in

Process and Utilities Engineering, in the area of renewable fuel technology and the techno-economics of power gen-eration. His core area of focus is in the field of renewable

energy and power generation. However, he also conducts research in the areas of vibration-based signal processing

and machine design for agricultural purpose.

Aaron D’ Arbasie is

a graduate student in the Master of Engi-neering programme at

Carleton University, Ottawa, Ontario, Can-ada. He graduated with

First class honours degree in mechanical engineering, from The

University of the West Indies. Aaron has a keen interest in solving problems using engi-

neering approaches.

1.0 Introduction

Working in the plastics packaging industry has introduced

me to the reality of how rapidly we consume plastic prod-

ucts. Of course, I’m aware that plastics are essential materi-

als in all areas of society, but their extensive use, slow deg-

radation and petroleum-based origins contribute to pollu-

tion and depletion of non-renewable resources. A 2010

waste characterization study commissioned by the Ministry

of Local Government found that plastics comprised of an

average of 19.525% of waste in Trinidad and Tobago’s four

primary landfills (Government of the Republic of Trinidad

and Tobago, 2015). This figure does not consider the plastic

waste that is currently littered throughout the country, find-

ing residence at roadsides, and in drains, rivers, and our

coastline. Moreover, plastic waste takes, on average, 450

years to decompose in the environment (National Oceanic

and Atmospheric Administration Marine Debris Program,

2018).

In recent years, sustainability has become an important con-

cern for governments, businesses and everyday citizens, as

the negative impact of human activities needs to be ad-

dressed. In 2015, the United Nations (UN) launched its Sus-

tainable Development Goals (SDG) mandate which focuses

on 17 key areas of global sustainability. But what does the

term sustainability mean? In the literature, sustainability is

commonly defined as “development that meets the needs of

the present without compromising the ability of future gen-

erations to meet their own needs” (Shah, 2008).

It encompasses three main pillars, namely environmental,

social and economic development as illustrated in Figure 1.

This short article considers the concept of environmental

sustainability in terms of environmental pollution and how

material innovation can potentially make plastics less harm-

ful to the environment and thus more sustainable.

Figure 1.0: The three interconnected pillars of sustainabil-

ity

According to Goodland (1995), the concept of environmen-

tal sustainability refers to sustaining global life-support sys-

tems indeterminately. Pollution is the biggest barrier to

achieving environmental sustainability, as the improper dis-

posal of waste materials harms ecosystems around the

world. With respect to plastic pollution, it is estimated that

about 79,000 tonnes of plastic are dumped in the Pacific

Ocean alone, continuously increasing the size of the now

infamous ‘great Pacific garbage patch’, that is currently three

times the size of France (Arora et al., 2018) as shown in

Figure 2. The innovation of products and processes are

needed to combat pollution and move closer towards creat-

ing a sustainable environment.

Bioplastics and Environmental

Sustainability: Some Thoughts

By: Trishel Gokool, BSc (UWI), MSc (Manchester), AMIMechE

Figure 2.0: Thermographic satellite image of the Great

Pacific Garbage Patch (Canelo, 2018)

Conventional plastics are petroleum-based and are typically

not biodegradable, both of which are undesirable character-

istics for environmentally sustainable materials. To this end,

new materials are being produced to reduce the environ-

mental impact of plastic products, namely, bio-based plastics

and biodegradable plastics, both of which are generally

termed ‘bioplastics’. Bio-based plastics, like the name sug-

gests, are derived from renewable resources such as corn,

soybean, bioethanol and lignin. Ideally, their production does

not rely on our ever-depleting petroleum resources, so,

producing these bio-based plastics will not only reduce cur-

rent petroleum usage, but we will still be able to produce

them when these reserves are exhausted. Biodegradable

plastics, on the other hand, are plastics that undergo physi-

cal and chemical deterioration and completely degrade into

carbon dioxide or methane, and water by microorganisms.

This action will considerably reduce the amount of time the

plastic remains in the environment. Bio-based plastics can be

biodegradable or nondegradable, and can also be molecular-

ly similar to existing plastics, such as bio-based PET

(polyethylene terephthalate), or completely new materials

such as PLA (polylactic acid).

However, although many bio-based polymers are biode-

gradable, not all biodegradable plastics are bio-based (Babu

et al., 2013). Some biodegradable plastics can also be de-

scribed as compostable and undergo degradation through

Figure 3.0: Degradation of a compostable bioplastic bottle

over the span of 80 days (Echo Instruments, 2016)

biological processes in industrial and home composts. Figure

3 shows the degradation of a compostable bottle over the

span of just 80 days. As observed, after 80 days it has de-

graded enough for the fragments to be invisible to the naked

eye. However, it must be verified that complete biodegrada-

tion has in fact occurred and not simply fragmentation, as

these fragments can remain in the environment for a long

of period of time and be just as damaging to the environ-

ment.

A major drawback of several of the new bioplastics is that

they cannot be used in current processing equipment. To

combat this issue, and maintain material performance, many

companies are offering additives that can be added in small

quantities to current feedstock, making the resulting plastic

product degradable. These companies use terms such as

“oxy-degradable”, “oxy-biodegradable” and “degradable” to

describe the products manufactured from the additive and

conventional plastic combination.

There has been much controversy surrounding these claims,

as a few emerging studies have shown that the additives do

not reduce the degradation rate of plastics (Selke et al.,

2015; Lambert and Wagner, 2017), whilst the additive man-

ufacturers are providing data that show otherwise. Standard

testing bodies like ISO and ASTM have been trying to devel-

op standard testing methods for degradability of plastics, but

with the absence of such standards, plastics manufacturers

and consumers must decide for themselves if the claims are

justified and the risk is acceptable.

At present, the testing done on these additives often refer

to ASTM D5338 and D5511, but although these are stand-

ard test methods, they are not standard specifications

(PLASTICS, 2018). Third party or in-house testing is a good

idea before introducing such additives to conventional res-

ins, as well as toxicity testing for plastics used in food pack-

aging and mechanical testing for high strength applications.

In advertising these blends as biodegradable, companies

must also ensure that they do not inadvertently promote

littering, as consumers may get the impression that these

products will harmlessly disappear in the environment.

Proper end of useful life recovery and disposal is required to

successfully dispose of these plastics, and care should be

taken to avoid the contamination of the waste stream by the

mixing of biodegradable plastics with nondegradable ones.

In order to satisfy the UN’s SDG, which includes ensuring

sustainable consumption and production patterns and build-

ing resilient infrastructure, promoting sustainable industriali-

zation and fostering innovation; Trinidad and Tobago must

step up and reduce environmental pollution.

Local plastic manufacturers should be looking towards sus-

tainable materials and processes to reduce future plastic

waste and engage in recycling drives to reduce the plastic

waste currently littered throughout the country. Moreover,

with the reduced supply of petroleum, bio-based plastics are

becoming increasingly attractive.

However, due to the absence of established standards, com-

panies and consumers alike have to decide on whether the

bioplastics they produce and/or use are in fact beneficial to

the environment, and both need to be proactive in the end

of life disposal and recovery of these plastic products.

Trishel Gokool is a part-time graduate student

at The University of the West In-dies, pursuing her PhD Manufactur-

ing Engineering. She is also em-ployed at ANSA

Polymer as a Management Trainee under the

Champions De-velopment Pro-gramme. In 2015,

she graduated with a BSc Mechanical Engineering (First Class Honours) from The University of the West Indies.

In 2018 graduated with an MSc Advanced Manufac-turing Technology and Systems Management (Distinction) from the University of Manchester,

UK. Her research interests include but are not limited to computer-aided design and manufactur-ing (CAD/CAM), additive manufacturing, process

optimization and engineering education.


Assessing The Sensitivity Of The East

Coast of Trinidad To Oil Spills

By: Nyoka Sinanan

1.0 Introduction

The east coast of Trinidad is host to both oil and gas pro-

duction and transportation activities. There are over thirty

gas fields and ten oil fields owned by both local and foreign

companies located off the east coast of Trinidad. Because

of the proximity of these fields to the coastline, the chances

of an oil spill occurring is very high and due to the wind and

current direction, spilled oil is most likely to impact the

coastline. The arrival of oil on beaches which are used for

recreation, sports and other amenities can adversely impact

on tourism. The biological effects on shoreline are also of

great concern especially in environmentally sensitive areas

such as the Mathura Turtle Nesting Ground and the Nariva

Swamp and also in areas where mangroves persist and are

in direct contact with the open sea.

Castanedo et al. (2009) stated that to respond quickly and

successfully to an oil spill in a defined geographic area, a

contingency plan, including information and processes for

oil spill containment and clean-up is required. A study un-

dertaken by Wieczorek, Dias-Brito, and Milanelli (2007),

aimed at developing an ESI, which followed procedures

determined by the International Convention of Oil Spill

Prevention, Preparedness and Response (OSPPR). These

procedures included separating the coastal habitats into

different littoral sensitivity indexes to oil spills. Both re-

searchers chose to classify the areas by looking at the bio-

logical, physical and socio-economic factors that would be

impacted. However, Castanedo et al. (2009) used a quanti-

tative approach when ranking the coast by using formulae

to decipher the vulnerability index of the area. Wieczorek,

Dias-Brito, and Milanelli (2007) relied on more of a qualita-

tive approach as he ranked the coastal habitats in 1- 10

vulnerability indexes such as exposed rocky headlands,

eroded wave cut platform, etc. Another research paper

done by Adler and Inbar (2007) classified the Mediterrane-

an Coastline of Israel into 13 ESI categories of sensitivity to

oil spills in a similar manner to Wieczorek, Dias-Brito, and

Milanelli (2007) . The classification is based on the concept

that shoreline sensitivity depends on the level of geological

and geomorphological characteristics, exposure to the

ocean, sediment size, biological resources, socio economic

patterns, current and ocean tides and wind speed and di-

rection.

The eastern coastline of Trinidad is classified using a quali-

tative approach. The classification is undertaken according

to the NOAA’s Guidelines as specified by the National Oil

Spill Contingency Plan for Trinidad and Tobago (Ministry of

Energy and Energy Affairs 2013). NOAA’s method for de-

veloping an Environmental Sensitivity Index (ESI) map, cate-

gorizes coastal habitats in terms of their sensitivity to

spilled oil by analyzing the physical, biological and social

factors along the coastline under study. It involves perform-

ing a coastal classification coupled with data on relative

exposure to wave and tidal energy, shoreline slope and

substrate type to rank the shoreline in terms of its suscep-

tibility to oil spills. The shoreline ranking combines with the

delineation of both biological and human use resources to

produce the ESI map.

Wave and tidal energy determine the degree of exposure

of the coastline. Wave heights exceeding 1m indicates that

the impact of oil spills on the coastline is reduced as off-

shore-directed currents generated by waves reflation pat-

terns push the oil away from the shore. Tidal-energy flux

must also be taken into consideration as there is the poten-

tial for strong tidal currents to remove stranded oil as tidal

currents generally increase as tidal range increases. High

energy means rapid natural removal, usually within days to

weeks. Low energy means slow, natural removal, usually

within years. Medium energy means that stranded oil will

be removed when the next high-energy event occurs,

which could be days or months after the spill (NOAA

2002).

The substrate types can be classified as bedrock, sediments

and man-made material. Table 1 shows the grain size for the

different types of sediments.

Table 1.0: Grain Size for different sediment types

(NOAA 2002), states that penetration occurs when oil

stranded on the surface sinks into permeable sediments. The

depth of penetration is controlled by the grain size of the

substrate, as well as the sorting. Penetration is more preva-

lent for coarse, well sorted sediments and as such oil can

penetrate up to 1m on gravel beaches. Trafficability is also

dependent on the substrate type. Highly trafficable shorelines

are ranked lower on the ESI scale than those on which clean-

up crews will have difficulty moving on or where their clean-

up efforts will cause additional damage. Fine-grained sand

beaches are typically compacted and hard with little chance of

workers trampling oil deep into the substrate. Coarse-

grained beaches tend to have moderate to steep slopes, are

much less compacted, and have a high permeability, making

walking difficult and more likely to drive any stranded oil

deeper into the substrate. Wetlands have very low trafficabil-

ity due to the innate softness of the substrate which makes

clean-up difficult (NOAA 2002).

The biological productivity of shoreline habitats is also im-

portant. Mangroves have the highest ranking because of the

potential for long-term impacts resulting from both exposure

to oil and

potential damages associated with clean-up activities in these

kinds of habitats. However, the presence of other sensitive

resources on a specific shoreline segment, such as turtle

nesting on a fine-grained sand beach, does not affect the ESI

ranking. These phenomena

are addressed by mapping biological and human-use re-

sources (NOAA 2002).

The map is produced using geographic information system

(GIS) techniques. The shoreline resources are ranked and

color-coded based on their sensitivity to oiling. The data on

biological and human resources also use standardized symbols

(NOAA 2002). Pincinato, Riedel, and Milanelli (2009) mod-

elled an expert GIS system based on knowledge to evaluate

oil spill environmental sensitivity. They stated that GIS stands

as a powerful resource to fulfil the limitations of traditional

environmental sensitivity maps. They visually mapped the

habitats based on a series of aerial photographs with a spatial

resolution of 0.98m per pixel. Wieczorek, Dias-Brito, and

Milanelli (2007) also used GIS mapping in their study. They

mapped the habitats under study from an orthophoto, which

enabled resolutions up to 1:2500.

Figure 1.0: Coastal Classification adapted from the IMA for

the north-east coast of Trinidad

Figure 2.0: Coastal Classification adapted from the IMA for

the south-east coast of Trinidad

Figures 1 and 2 show coastal classification maps that

were adapted and updated from the IMA (1983). To-

gether with the wave, tidal, slope and grain size data

(table 2), the coastal classification is compared to the

guidelines given by NOAA (table 3) and the areas are

ranked in terms of their sensitivity to oil spills (figure 3

and 4). It should be noted that table 3 is a modified

version of NOAA’s guidelines as it has been made to

fit the coastal environment of Trinidad.

Table 2: Data used to apply IMA’s modified version of

NOAA’s shoreline sensitivity ranking to the East

Coast of Trinidad (The United Kingdom Hydrographic

Office Admiraility EasyTide 2017) (Institute of Marine

Affairs 2013).

From table 2, eight out of the nine beaches along the

coast are classified as fine-grained sand beaches. A

matrix was applied as seen in table 4 and areas that

consisted of fine-grained sand, low hydrodynamic lev-

els and flat to moderate slopes were ranked as ESI 4

as oil would not be readily removed from these areas

as compared to areas that have a higher hydrodynamic

level and steeper slopes.

Table 2.0: Data used apply IMA’s modified version of NOAA’s shoreline sensitivity ranking to the East Coast of

Trinidad (The United Kingdom Hydrographic Office Admiraility EasyTide 2017) (Institute of Marine Affairs 2013)

SITE WAVE HEIGHT (CM) TIDAL ENERGY (M) SHORELINE SLOPE

GRAIN SIZE

(mm)

Salybia Bay 23-30 – 1.2 6.5˚ 0.35- 0.5

Cumana Bay - 0.1 - 1.3 7.2˚ 0.5- 1.4

Sena Bay 180 0.1 - 1.3 9˚- 13.1˚ 0.5

Balandra Bay 40 0.1 - 1.3 4.3˚ 0.18- 0.25

Saline Bay 48 0.1 - 1.3 6.1˚- 10.1˚ 0.18- 0.5

Matura Bay - 0.1 - 1.3 6.5˚- 13˚ 0.25-0.5

Manzanilla Bay 60-78 0.2 – 1.4 4˚- 5˚ 0.125- 0.25

Cocos Bay 60-78 0.2 – 1.4 5˚-7˚ 0.125-0.25

Mayaro Bay 58-71 0.1 – 1.4 7˚ 0.125- 0.25

The six shoreline habitat rankings found along the east coast

of Trinidad are ESI 1- Exposed vertical rocky shores; ex-

posed seawalls, ESI 3- Fine-grained sand beaches, ESI 4 –

Coarse-grained sand beaches, ESI 6- Gravel beaches/Riprap,

ESI 7 -Sheltered rocky shores/ Seawalls/ Vegetated banks;

Solid man-made structures and ESI 10- Mangroves. An ESI

ranking of 1 corresponds to exposed vertical rocky shores

or exposed seawalls. It consists of elements such as the

coast being exposed to high wave energy which tends to

keep oil offshore as the impermeable substrate allows oil to

remain on the surface where natural processes will allow

for removal (NOAA 2002). This means that no clean- up is

required. Approximately 26.84km of the eastern coast is

ranked as ESI 1.

ESI 3 comprises of fine-grained sand beaches with semi-

permeable substrate where oil penetration is limited and

beach slopes are very low. Grain size analysis done on

Table 3.0. Modified classification for Trini-

dad and Tobago (IMA 1996).

Table 4.0. Matrix used to determine sensitivity

ranking for areas consisting of fine-grained sand

Figure 3.0. ESI map for the north-east coast of Trinidad

Figure 4.0. ESI map for the south-east coast of Trinidad

samples collected found the modal grain size to be between

0.06mm to 1mm which is classified as fine-grained sand by

NOAA (2002). 65.6km of the east coast of Trinidad is

ranked as ESI 3. A ranking of ESI 4 relates to permeable

substrate where oil penetration occurs up to 25 cm deep,

the slope is intermediate and the sediments are soft with

low trafficability (NOAA 2002).Grain size analysis done de-

duced the grain size to be between 1-2mm which indicates

it is of a coarse nature. Coarse-grained sand beaches are

ranked higher than fine-grained sand beaches as it is easier

for oil to penetrate which makes clean-up difficult. 9.7km of

the coast is ESI 4.

Cumana is the only area consisting of coarse- grained sand

but due to the selection matrix (Table 4) Salybia, Balandra

and Saline are also ranked as ESI 4 as the other sensitivity

ranking factors increase their susceptibility to spilled oil.

Manzanilla, Mayaro and Cocos are fine- grained and are cat-

egorised in the orange region of the matrix. They however

are ranked lower as ESI 3 because the hydrodynamic levels

in these areas are higher which would aid in the removal of

oil that makes landfall along these shorelines.

Due to erosion of the road along the Manzanilla/ Cocas

stretch, a boulder revetment was constructed just North of

the Ortoire river. This 0.7km of the coast was given a sensi-

tivity ranking of ESI 6. The riprap is in direct contact with

the water which makes it easy for oil to reach the boulders.

Flushing can be effective for removing oil but large amounts

of residue may remain depending on the type of oil (NOAA

2002).

Recent diversification of Manzanilla beach has also seen the

construction of a seawall along the foreshore area. This

0.2km of the coast receives an ESI ranking of 7. Seawalls are

man-made and are prone to oil spills as clean-up is difficult

for aesthetic reasons. Seawalls may also have a large number

of attached organisms which supports an ecosystem that

can be affected by a potential oil spill (NOAA 2002).

An ESI rank of 10 was designated to one of the most sensi-

tive parts of the east coast of Trinidad. All of the mangrove

systems along the east coast of Trinidad are not in direct

contact with the open sea but are located behind, and are

thus protected by beaches.

However, where river mouths connect to the ocean, a

threat is introduced in terms of the oil reaching the man-

groves via the river routes. In Figure 3 and 4, the areas

ranked ESI 10 are very minute because of how small the

areas at the mouth of the rivers are. Collectively 0.5km of

the east coast is ranked as ESI 10. Mangroves, marshes and

other vegetated wetlands are the most sensitive habitats

because of their high biological use and value, their difficulty

to clean-up, and the potential for long-term impacts to

many organisms (NOAA 2002).

Observations from previous spill events have shown that

mangroves undertake tremendous amounts of degradation

when oil comes in contact with it and that these ecosystems

are difficult to protect and clean up because of their intri-

cate nature (NOAA 2014b). The oil covers the pneumato-

phores of the mangrove trees which reduces its oxygen

supply.

Toxicity is another factor of concern as oil containing low

molecular weight aromatic compounds can damage the cell

membranes in the roots of the mangrove which results in

an increase in the intake of salt from the water which slowly

kills the trees. The fauna present in mangroves are also at

risk as oil may penetrate burrows in the sediments which

kills microorganisms, crustaceans etc. that are present

there.

Along with mangroves, there are biological species along the

coast that would be at risk because they are endangered

and highly valued due to their rarity. These Species include

the Leatherback sea turtle, Donax Clams and the West

Indian Manatee. Leatherback sea turtles use areas such as

Matura, Fishing pond, Manzanilla, Mayaro and Salybia as

nesting grounds. Matura (ESI 3), is a major turtle nesting

sites but based on shoreline sensitivity, it is ranked low on

the ESI map however, because of the presence of Leather-

back turtles, the areas become high priority and protecting

them are of utmost importance.

An oil-contaminated environment can be lethal to both sea

turtles and incubating eggs. Since a sea turtle exists in differ-

ent habitats throughout its life cycle, an oil spill can affect it

at every stage in its life. The ESI maps (fig. 3 and 4) also

shows turtle breeding areas offshore which are indicated by

the large circles. Satellite telemetry show that sea turtles

spend much of their time directly off the nesting beaches

and up to 30 km offshore (Eckhart 2010). It would there-

fore be important that oil be prevented from reaching these

areas to ensure the protection of the breeding turtles off-

shore. Protecting the sea turtles that visit the island holds

environmental as well as economic importance.

Another biological resource that is indigenous to the east

coast of Trinidad is the Donax clams, commonly known

locally as “chip-chip.” These tiny shell type creatures are

prolific filter feeder that provides an important link in

coastal food chains, including sea birds and people. Because

they are filter feeders, Donax clams tend to absorb pollu-

tants through direct contact with contaminated water and

suspended particles (Snyder et al. 2014) which makes it pos-

sible for the transfer of oil components to other species in

the food chain.

An oil spill not only damages the biological factors along the

coast but also aesthetically degrades the environment as

well as causes pungent aromas that can cause health prob-

lems. Along the East Coast of Trinidad, there are two main

human use resources, fish landing sites and beaches. Beach-

es span the length of the coast and there are many popular

recreational bathing areas commonly visited by tourists and

locals. Fish landing sites are small infrastructures present in

areas where fishing takes place i.e. where fish is caught and

sold locally and on a small scale. When exposed to oil, adult

hain. Indefinitely, this means that consumers would desist

from buying produce caught in areas where oil spill have

occurred.

All in all, the amount of oil which reaches a shoreline is de-

pendent on the volume of oil spilled, the degree of weather-

ing, the nature of the coastal and marine environment and

the point of release of the oil. Depending on the type of

shoreline, the effects of the oil varies. If an oil spill does

reach the shoreline, the methods put in place to remove the

oil slicks should cause no further harm to the environments.

Dispersants such as Corexit 9500A and 9527A which were

used in the Deepwater Horizon Oil spill which occurred in

the Gulf of Mexico has been said to have negative impacts

on marine life. Dispersants also pose a significant threat to

human health as well as it contains 2-Butoxyethanol which

may affect the liver, kidney and red blood cells (Centre for

Biological Diversity 2017).

It is therefore necessary that authorities create clean-up

strategies prior to the occurrence of an actual oil spill that

would not depreciate the coast more than the effects of the

oncoming oil. The ESI maps produced from this research,

Figures 3 and 4, shows the sensitive areas along the coast

and would allow officials to conceptualize methods to effi-

ciently and effectively protect what is at risk.

Nyoka Sinanan has completed her BSc. in

Civil with Environmental Engineering from the Uni-versity of the West Indies

and is also pursuing her MSc in Coastal Engineer-ing and Management in

UWI St Augustine. Cur-rently she works as a Coastal Design Engineer with the Ministry of Works and Transport where she

hopes to gain substantial work experience in the field.


A Sustainable Solution for Red Mud in

the Caribbean.

By: Gino Hosein and Professor Indrajit Ray

1.0 Introduction

Due to the current mining of bauxite in the Jamaica and

Guyana, there has been a large quantity of bauxite waste

material or “red mud” being produced. Red mud is one of

the major solid waste residue generated due to digestion of

bauxite ores with caustic soda during the Bayer process of

alumina production. According to the Jamaica Bauxite Insti-

tute (JBI) approximate 4 million tonnes of red mud are pro-

duced annually. The bauxite company of Guyana states on

its website that the annual production capacity of bauxite is

2.3 million tonnes. About 1 tonne of alumina (aluminum

oxide) is produced from 3 tonnes of bauxite, and depending

on the quality of ores processed, 1-2.5 tons of red mud

waste is generated for every tonne of alumina. By applying

this rule of thumb, it may be estimated that 1.15 million

tonnes of red mud are produced annually in Guyana. This

works out to be 5.15 million tonnes of red mud produced in

the Caribbean out of an overall 170 million tonnes being

produced globally in 2015 (Hua, Heal and Friesl-Hanl, 2017)

which means an average of 3.2% of the annual global produc-

tion of red mud. This signifies that red mud is one of the

most abundant waste materials produced in the Caribbean.

2.0 Reduction of the Disposal Problem by Replacing Port-

land cement

The problem faced regionally can be solved by finding a

sustainable method to dispose of the red mud. Dust repre-

sents a major pollution factor in the bauxite industry

(Traore, Traore and Diakite, 2014). The current global prac-

tices for disposal of red mud include sea disposal, ponds (see

fig. 1), mud farming, and dry mud stacking. All these are

highly unsustainable and environmentally hazardous due to

high alkaline nature of the sludge. The projected global pro-

duction of cement by 2020 is 4.4 billion metric tonnes. If we

apply the pro rata method of the Caribbean population (44

million) against the world population (7500 million) we get

the following projected consumption of cement for the Car-

ibbean: (44/7500)*4.4 = 0.03 billion metric tonnes. This is 30

million metric tonnes of cement estimated to be consumed

by the Caribbean in 2020. It is well known that manufactur-

ing of cement causes large amount of greenhouse gas (1000

kg of Portland cement produces about 927 kg of CO2)

(Portland Cement Association) and cement kiln dust (CKD)

that is disposed as landfill. The energy consumption due to

Portland cement manufacturing is 5 GJ/tonne. Due to large

quantities of Portland cement production, the total energy

consumption becomes quite high. If a large fraction of the

5.15 million tonnes of estimated red mud from the Caribbe-

an can be recycled to replace part of the Portland cement

clinker – this will readily lead to a sustainable solution.

Figure 1.0: Typical Pond Disposal for “Red Mud”

3.0 Reduction of the Disposal Problem by Replacing Port-

land cement

For manufacturing purpose, the red mud can be either used

to make composite cement by replacing part of the Portland

cement or it can be used to produce alkali activated cement.

Due to simplicity and availability of more research data the

greater potential will be to manufacture composite cement.

Research revealed that up to 20 wt% of cement can be sub-

stituted by red mud to produce durable mortars and con-

crete (Ribeiro et al. 2013). The incorporation of red mud to

produce composite cement has many benefits such as: (1)

recycling of the hazardous red mud will eliminate the dispos-

al problem; (2) the replacement of Portland cement clinker

with red mud will reduce CO2 emission and CKD production; and

(3) reduction of the clinker will reduce energy requirements. Fur-

ther, the concrete made with red mud composite cement will re-

duce the heat of hydration and as a result will reduce the chance of

cracking of concrete structures. The red mud inclusion in the clink-

er will increase the resistivity of concrete which eventually will re-

duce the corrosion potential of reinforcements embedded in con-

crete.

Table 1.0: Chemical Composition for Portland Cement and

Red Mud

As seen in table 1, above, the silica (SiO2) content of red mud is

almost the same as the Portland cement but the alumina (AI2O3)

content is much higher -- both of these values make it a good blend-

ing material with cements. The major concern is the high content of

alkalis which tend to raise the pH value. The high pH is good against

the corrosion attacks on reinforcement and carbonation of con-

crete, but excessive sodium oxide (Na2O) and potassium oxide

(K2O) in the presence of moisture will increase the chance of alkali-

aggregate reaction if the aggregate is a reactive aggregate. However

reactive aggregates are very rare in the Caribbean.

4.0 Potential Challenges for the Implementation of Red

Mud Cement

As with all new products, general acceptance by all stakeholders

including homeowners, clients, contractors, Government, lending

agencies etc. will be slow. More research is needed for quality con-

trol testing of the properties of composite cement with varying

quantities of red mud. Key tests are needed for complying with the

ASTM standards for physical and chemical properties of blended

cement such as oxide compositions, insoluble residues, X-ray dif-

fraction, electron microscopy, pH values, and particle distributions,

surface areas, setting time, mortar strengths, soundness and other

quality control tests. If these tests are done systematically and a

database can be created for the process and the results, it can be

used repeatedly. The import costs have to be accounted for all of

the island states, other than Jamaica and Guyana, who may wish to

use the red mud. The only viable way to import the red mud is to

firstly treat it to a safe environmentally friendly state and barge it to

the various islands. The only other possibility is for Jamaica and

Guyana to produce the actual cement blends and export. The initial

quality control testing along with the import of the materials may

initially raise the cost of production, but for large productions later

on the cost will eventually be much less. The benefits of lower

greenhouse gas, more durable concrete, and recycling of red mud

will be much higher -- thus will significantly lower the cost/benefit of

the product.

5.0 Conclusions

As discussed above, the main conclusions are:

1). Red mud is the most abundant waste material produced in the

Caribbean.

2). There is a need for recycling this waste material in order to

contribute to a sustainable development.

3). It is possible to achieve this by using it as a partial cement re-

placement, up to 20wt%, for mortar and concrete applications.

4). Regionally some of the problems faced are the current disposal

methods, and the potential testing required for implementation of

the “red mud” as a recycled product.

Mr. Gino Hosein. BASc. in Civil Engineering.

MSc. in Construction Management. Diplomas in

Construction and Building and Draughting. Asso-

ciate Member APETT, Chartered Member of the

CIOB (MCIOB). Chartered Construction Manag-

er, 16 years construction experience in civil infra-

structure projects including roads, bridges, retain-

ing walls, infrastructure works to accommodate

MEP services i.e. plumbing, electrical etc., devel-

opments and building works including residential,

commercial, educational, health and recreation buildings. Worked in

pre and post contracts not exceeding US$ 20M. Mr. Hosein’s re-

search, to date, is focused on local challenges of the construction

sector in relation to construction management processes.

Professor Indrajit Ray. BS (Hons) in Civil Engi-

neering, MS in Structural Engineering, Ph.D.in Civil

Engineering. Dr. Indrajit Ray is currently the Pro-

fessor and Programme Coordinator of Construc-

tion Engineering and Management in the Depart-

ment of Civil and Environmental Engineering UWI.

Professor Ray’s research is focused on advanced

and sustainable construction materials, fiber rein-

forced polymer/concrete composite for repair and

strengthening, and local challenges of construction

sectors. Professor Ray has published over 125

peer-reviewed papers in Journals and proceedings, reviewed several

international Journal papers, and funding proposal. He led over US

$5 million externally funded projects. He has supervised over 45 MS

and PhD students and made several international presentations as

invited speaker. Professor Ray is the voting member of ASTM Inter-

national committees on cement and concretes & aggregates, and

member of institution of engineers and geotechnical society.


KMA IN-PLANT COLD RECYCLING

TECHNOLOGY IN ROAD CONSTRUCTION

AND REHABILITATION IN TRINIDAD AND TOBAGO

By: Laurence Bridgemohan, BSc., MSc (UWI), REng. MAPETT, PMP

1.0 Introduction

The cold recycling technology offers a sustainable option for

road construction and rehabilitation, with increased global

applications, of significant success. Its accompanying eco-

nomic, environmental and energy efficient benefits has pro-

moted its use in the construction and rehabilitation of major

heavily trafficked carriageways in Trinidad. The introduction

of the Cold In Place Recycling rehabilitation technique in

Trinidad and Tobago by Danny’s Enterprises Company Lim-

ited has positively impacted the local road building industry,

with its entry over a decade ago, as an innovative pavement

engineering solution

In light of ongoing local infrastructural development, in-

creased demands for suitable road building aggregates have

been placed on our depleting local natural deposits of lim-

ited supplies of quality virgin granular aggregates. Fortunate-

ly, global advancements in equipment and road construction

techniques currently provides opportunity for the improve-

ment of a wide range of locally available aggregates and sub-

sequent satisfactory inclusion into road bases and sub bases.

The versatility offered by the Wirtgen KMA 220 Mobile

Cold Recycling Plant now provides for the utilization of the

Cold In-Plant stabilization technology towards the enhance-

ment of our local available materials. The KMA In-Plant sta-

bilisation technology allows for value to be added to local

aggregate materials not initially considered satisfactory for

pavement construction and rehabilitation application in its

parent form, providing a sustainable material source option

to the road building industry.

Figure 1.0 KMA Cold in Plant Stabilization

The KMA Cold in Plant Stabilization methodology utilizes

the enhancement provided by foamed bitumen, cement and

hydrated lime stabilizing agents, towards the improvement

in strength and durability properties of the aggregate. The

process allows for the controlled blending of dual aggregate

sources and meter controlled addition of stabilizing agents,

resulting in the production of a stabilized aggregate of im-

proved properties. The methodology provides for the

placement of these stabilized aggregates utilizing typical as-

phalt pavers with significant advantages inclusive of im-

proved efficiency, levels and grade controls.

Foamed Bitumen Stabilization

Foamed Bitumen or expanded bitumen is produced when

hot bitumen comes into contact with cold water in the

presence of compressed air. The resultant is vapour trapped

in thousands of tiny bitumen bubbles, which burst upon

mixing, producing splinters that adhere to the finer particles

of the aggregate material. Upon compaction, the mastic cre-

ated between both expanded bitumen and fine components

introduces spot welds to the coarser fraction of the aggre-

gate skeleton, resulting in the

production of a non-

continuously bound layer

(Wirtgen GmbH 2012, 107).

Figure 2.0 Section of BSM1-ACG

compacted layer core

(Bridgemohan, 2018)

Bitumen Stabilised Materials (BSMs)

BSMs produced from foamed bitumen stabilization behave

in a manner similar to unbound granular material, but with a

notable improvement in cohesive strength and a reduced

moisture sensitivity. Its main features include:

• A material with increased cohesion in excess of 3 times

its original value.

• Increased flexural strength.

• Increased moisture sensitivity

Cement Stabilization

Cement stabilization serves as one of the oldest forms of

aggregate treatment utilized in pavement engineering. The

process involves the mixing of selected aggregate materials

with cement and water, which hardens after compaction

and resulting in the production of a stiff, durable pavement

layer. The hydration of the calcium silicate compounds pre-

sent in the cement produces the calcium silicate hydrate

gel, which on hardening and curing holds the aggregate par-

ticles together. The resultant is a stabilized material of in-

creased stiff-

ness, durabil-

ity, compres-

sive and ten-

sile strength.

Figure 3.0 Stabilized Aggregate Pavement Systems

vs Conventional Granular Aggregate Pavement Sys-

tems

Figure 4.0 CBR 5 in-situ subgrade/

KMA BSM1 Stabilized Base

Estimated Capacity = 3 MESA to 4 MESA

Figure 5.0 CBR 5 in-situ subgrade

CBR 80 Unbound Granular Agg. Base

Estimated Capacity < 1 MESA

Owing to its improved shear and flexural strength proper-

ties, stabilized aggregate layers allow for the design and

construction of stabilized pavement systems with overall

increased carrying capacity. In light of these characteristics,

when proposed as alternatives to granular aggregate pave-

ment structures, stabilized pavement systems consist of

structural layers of reduced thicknesses. In addition to the

opportunity for inclusion of a wide range of available mate-

rials, the option for thinner stabilized structural high capaci-

ty layers provides for significant economic savings.

2.0 Typical Benefits of the KMA Cold In Plant Stabiliza-

tion Methodology

• Stabilized material of improved engineering strength

and durability properties consistent with increased

pavement layer carrying capacities and resultant eco-

nomical, durable pavement designs and construction.

• KMA in plant aggregates are laid in single passes, using

the conventional asphalt pavers to the desired thick-

nesses, grade and levels, allowing for higher site pro-

duction rates.

• Provides for blending and enhancement of a wide range

of locally sourced marginal aggregates, with monitored

consistency in quality and subsequent fulfilment of re-

quirements for its inclusion in pavement structures.

• Stabilized aggregate produced in-plant allows the mate-

rial to be pre-mixed, sampled, inspected and tested,

with allowed adjustments to input parameters and mix-

ing times as required.

• In-plant stabilization provides for a durable layers as

base or sub base layers in designed pavement struc-

tures and may also be considered for surfaces for tem-

porary unpaved applications.

3.0 Construction Applications In Trinidad

Sir Solomon Hochoy Highway – Southbound vicinity

of Gasparillo Bypass Road: August 2018

Project Details: KMA BSM 1 – RAP Rehabilitation Alternative:

Cold Milling of existing thick asphaltic concrete layers, cold in-

place sub base strengthening, KMA BSM1-RAP layer and reduced

thickness HMA surfacing.

Soogrim Trace Connector, Endeavour Trinidad: 2017

- Ongoing

Project Details: Alternative Stabilized Design: KMA BSM 1 – AGG

base / KMA CSM-RAP sub base – Installation of KMA in-plant

cement stabilized sub base, reduced thickness BSM1-AGG base

and reduced thickness HMA surfacing.

3.0 Conclusion

KMA In-Plant BSM 1 – RAP layer open to vehicular traffic 7

days before asphalt surfacing

The KMA In-plant cold recycling technology serves to ad-

dress concerns with respect to increasing demands for con-

sistent supply of high quality road building aggregates. The

opportunity for

improvement and inclusion of a wider range of available

materials is indeed a sustainable option with immense po-

tential benefits to the local industry. Successful applications

in Trinidad to date are indicative of the value of the tech-

nology as an innovative engineering solution, in suitably

designed and constructed applications.

Laurence Bridgemo-han is a national of Trini-

dad and Tobago and Civil Engineer presently in-volved in pavement engi-

neering research, design and construction. Mr. Bridgemohan is a holder

of a BSc in Civil Engineer-ing and MSc in Construc-

tion Management from the University of the West Indies (UWI), St. Augustine Campus and is a current

Civil Engineering PhD Candidate at the UWI, with ongoing research in the field of bitumen stabilized materials. He is a Registered Specialist Engineer with

the Board of Engineering of Trinidad and Tobago, in the field of Roads/Asphalt and is actively engaged in research, design and construction applications utilizing

stabilised materials, as sustainable pavement rehabili-tation and construction solutions. His recent projects include stabilization technology transfer activities in

the Caribbean and Latin/Central American regions, working alongside global industry pioneers, Wirtgen Group (Germany), Loudon International (South Afri-

ca) and Resansil Inc. (Miami).


The “Human” case for Energy Efficiency

in Trinidad and Tobago

By: Sheena Gosine

1.0 Introduction

Social and economic development and population growth

have resulted in increased global energy demand over the

last decade. Worldwide electricity production, one com-

ponent of energy supply, has increased by 76%. Total

worldwide CO2 emissions per Gt per year has however

also increased by 44% from 1993-2011, reaching 31.6 Gt in

2012 (World Energy Council 2013). Despite the rapid in-

crease in energy use, almost 20% of the global population

has no access to electricity (GEA 2012) and over three

billion people still rely on traditional fuels for household

cooking and heating. Consequently, the resulting air pollu-

tion leads to the occurrence of over two million premature

deaths annually, largely women and children. Energy there-

fore is central to addressing major the challenges sustaina-

ble economic and social development and global security

(GEA 2012).

According to International Energy Agency (IEA), the global

demand for electricity has increased, and electricity genera-

tion from fossil fuels has increased from 4,606 TWh in

1973 to 15,396 TWh in 2012 so that 67.9% of the world’s

electricity has been produced by fossil fuels (International

Energy Agency 2014). Governments are increasingly con-

cerned about the security of electricity supply and question

the ability of existing market design and regulatory frame-

works to continue to deliver reliable and efficient electricity

supply in a timely manner (IEA;OECD 2013).

Energy Efficiency refers to technical improvements that

result in using less energy without a reduction in consumer

enjoyment (Hofmeister, 2010). Energy efficiency has been

an active and inexpensive tool to offer environmental pro-

tection, stimulate economic growth and improve energy

security. Historically, the focus of international and domes-

tic energy law has been on maintaining adequate supply of

energy, rather than maximizing generation and utilization of

energy efficiency measures (Bradbook & Richard, 2003).

Reducing energy use through existing processes offers

many possibilities. Some of these options have little or no

cost, energy conservation actions, cost nothing to imple-

ment. Energy conservation is any action that results in the

use of less energy and energy efficiency requires us to use

technology in a way that requires less energy to perform

the same function.

The world’s demand for energy has resulted in low energy

prices, some maintained by unrealistic subsidies avoiding

the “true” social and environmental costs. Energy subsidies

depress economic growth in many different ways. Subsidies

can discourage any type of “investment in the energy sec-

tor; crowd out other public spending that would enhance

growth and over the long term diminish the competitive-

ness of the private sector” (Bauer, et al., 2013). Subsidies to

consumption or production result in the lowering of end-

user prices, this can lead to increased rates of energy use

and act as a deterrent to conserve or use energy more

efficiently (United Nations Environment Programme, 2008).

Two-thirds of global greenhouse-gas emissions are derived

from the energy sector (International Energy Agency 2013)

it will be pivotal in determination of achievement of climate

change goals. On the 12th, December 2015 at COP 21 in

Paris, Parties to the UNFCCC reached a landmark agree-

ment to combat climate change called the “Paris Agree-

ment”. The Paris agreement generally aims to increase the

ability of countries to mitigate the effects of climate change,

and at making finance flows consistent with a low GHG

emissions and climate-resilient pathway (UNFCC, 2015).

The choices people make about how they use energy af-

fects the environment and everyone's lives. The earth’s

average surface temperature has reportedly increased over

the last century. This increase in temperature change has

been linked to anthropogenic sources such as greenhouse

gases (GHG). In 2013, globally energy use accounted for

72% of the GHG emissions, 31% of this was due to electric-

ity and heating utilization (Global Emissions, 2018).

2.0 Understanding Electricity in Trinidad and Tobago

T&T meets all of its domestic electricity needs locally and

therefore does not import or export electricity (Manickchand

2011). The power generation sector in Trinidad and Tobago

can be broken down into: one transmission and distribution

company (the Trinidad and Tobago Electricity Commission, or

T&TEC) which purchases its bulk power from three (3) inde-

pendent power producers, namely; The Power Generation

Company of Trinidad and Tobago (PowerGen), Trinity Power

and Trinidad Generation Unlimited (TGU) (Parliament of the

Government of Trinidad and Tobago 2013).

T&TEC purchases electric power for resale to its domestic,

commercial and industrial customers, the company is also

responsible for purchasing natural gas for the generation

companies from the National Gas Company of Trinidad

&Tobago Limited (NGC) (McGuire, Competition in Energy

Markets: Trinidad and Tobago 2007). The total supply availa-

ble with full TGU capacity on the grid is 2,155 megawatts and

the peak demand is 1,322 megawatts (Parliament of the Gov-

ernment of Trinidad and Tobago 2013).

Cheaper electricity is obtained through the economy of scale:

that is, the bigger the generator, the less expensive the power

produced on a per unit basis. However, large generators are

no more than 40% efficient (Martin May 2009) which results in

wasting of natural resources. The efficiency of Trinidad and

Tobago’s the centralized system has come under scrutiny over

the past decade. The evidence suggests that our generating

plants have been deemed inefficient and plans have been made

for replacing them. Our current power generation plants have

low thermal efficiencies. The TGU, La Brea Power Station had

the highest efficiency when compared to the other power

stations as a result of a combined cycle arrangement of

450MW of gas and 270MW free combined cycle that is, it

uses the steam from the 450MW of electricity to generate a

further 270MW of electricity (Parliament of the Government

of Trinidad and Tobago 2013). In T&T the IPP’s receive pay-

ment based on their ability to make power available when

called upon and cannot contractually earn revenue from the

byproducts of energy. T

his type of contractual arrangement does not encourage ener-

gy efficiency upgrades (Driver, 2017). The electricity sector in

Trinidad and Tobago is the second highest contributor to

GHG emissions. The power sector experienced an immense

growth in emissions of 174% growth from 1990-2012

(GoRTT, 2015). Residential customers currently consume

approximately 33% of all electrical energy produced, whereas

industrial and commercial customers utilized approximately

55% and 10.0% respectively (Ministry of Energy and Energy

Industries, 2019)

T&TEC purchases natural gas from NGC in US dollar denomi-

nation and this increases annually at a rate of 4% (RIC 2003).

Sixty percent of T&TEC’s operational costs are from money

spent on fuel purchases and conversion to energy, the financial

viability of T&TEC would be adversely affected if the govern-

ment changes these price structures. (T&TEC 2010). T&TEC

has identified a series of issues that must be addressed for

their sustainability and success: the reduced natural gas re-

serves, the increasing of natural gas prices, rising generation

costs and intensifying global competition and prices for electri-

cal inputs (T&TEC 2010). Over the years fuel has been sold to

T&TEC at reduced costs, however, as electricity demand has

increased so has fuel consumption for electricity generation

and as a result there has been increased expenditure by

T&TEC.

3.0 Electricity Pricing and Demand in Trinidad and Tobago

There are five classes of customers in Trinidad and Tobago:

Residential, Commercial, Industrial, Heavy Industrial and

Street Lighting. The rate structure for residential electricity

customers uses a three-tiered system where the tiers are de-

fined on the basis of electricity usage, which is measured in

kilowatt-hours (kWh) over a two-month billing cycle, the oth-

er customers are billed monthly at a specific energy rate. The

three (3) residential usage categories are as follows: 1-

400kwh, 401-1000kwh and >1000kwh.

The industries are required to also pay maximum demand

charges, they are required to submit the planned Maximum

Demand of their plant in kVA (the Reserve Capacity) when

requesting a supply (RIC 2009).

Electricity tariffs in T&T are reviewed annually and within the

review period the annual tariff adjustments have not always

changed. NGC provides T&TEC with the required gas at a

reduced rate determined by government. This is the reason

why Trinidad and Tobago’s customers have the benefits of

the lowest price of electricity in the region (McGuire, Com-

petition in Energy Markets: Trinidad and Tobago 2007).

There has been growth in customer categories over the

years, resulting in increased demand for electricity in Trini-

dad and Tobago. The Energy Chamber of Trinidad and Toba-

go conducted research in 2017 on the analysis of the elec-

tricity subsidy through the Energy Efficiency and Alternative

Energy Committee. Despite having three (3) residential con-

sumption categories at various prices, roughly 43% of all

households in the country fell in the highest usage category

of >1000kwh. In addition the average bi-monthly consump-

tion of these households in 2015 was roughly 2100kwh (The

Energy Chamber of Trinidad and Tobago, 2017). The high

level of electricity consumption in Trinidad and Tobago is

most likely due to the low cost of energy and electricity,

which can influence customers to inefficiently utilize their

appliances and light fixtures (OLADE, 2012).

4.0 The effects of poor electricity utilization on Human

Development

The long-term progress of a country can be assessed

through the HDI and it is measured in three basic dimen-

sions of human development: a long and healthy life, access

to knowledge and a decent standard of living (United Nations

Development Programme, 2019). Trinidad and Tobago’s HDI

value for 2018 is 0.784 which is in the high human develop-

ment category, the country ranks at 69 out of 189 countries

and territories (United Nations Development Programme,

2019).

An empirical analysis concluded, that there is a clear correla-

tion between electricity consumption per capita and social

and economic development indices such as GDP (Leung &

Meisen, 2007) . T&T’s level of socioeconomic development

should be higher due to its high electrical energy consump-

tion. However, this translation is not observed when socio

economic development is measured in terms of the Human

Development Index (HDI) (UNDP, 2011).

Economic growth can be stimulated by increasing electricity

consumption per capita and hence indirectly achieve en-

hanced social development (Leung & Meisen, 2007). The HDI

of T&T can be found to be considerably lower than that of

countries that have similar per capita energy and electricity.

T&T has shown poor utilization of its electrical energy, which

has contributed to T&T’s lower HDI value, this value indi-

cates that the country should be benefitting more from its

high energy consumption, but it does not (Ugursal, 2011).

The Energy Chamber stated “there are approximately

400,000 households in T&T putting the average number of

persons per household at ~3 persons per home. While the

average North American household is slightly smaller at ~2.6

persons per household there is still a large gap between both

the standard of living and income levels between T&T and

North America”.

One contributing factor to this lower HDI value is the level

of poverty and hunger present in T&T, despite its developed

status. Poverty plagues the society, over 20 per cent of peo-

ple are assessed as living below the poverty line.

(Commonwealth Foundation, 2013). Another contributing

factor to the lower HDI value of T&T is child mortality that

is, the “probability of dying between birth and five years of

age per 1,000 live births”. Countries with high GDP values

normally have lower child mortality rates. The research con-

ducted by the Energy Chamber also identified a relationship

between the level of income and electricity utilization in

T&T. The Energy Chamber stated, “43% of homes in T&T

have a consumption level that is on par with the average

North American home, twice that of the average European

home and 3 times the global average. Moreover, 70% of all

residential power in Trinidad and Tobago is consumed by

this 43% which to some extent illustrates the level of income

inequality in the country”.

5.0 The future of Energy Efficiency in Trinidad and Tobago

One of the policy objectives of the Government of Republic

of Trinidad and Tobago is to promote energy efficiency and

energy conservation across all sectors, in order to reduce

our “Carbon Footprint” as well as to better utilize our finite

petroleum resources. The government’s target is that by the

year 2021, at least 10% of the electricity generated in T&T

should be from renewable sources.

The United Nations Sustainable Development Goals (SDGs)

which were adopted in 2015, with goals to combat climate

change and its impact as well as to ensure sustainable con-

sumption and production patterns. In December 2015, the

Trinidad and Tobago adopted the Paris agreement and rati-

fied it on February, 22nd, 2018. This agreement serves as a

legal framework for reducing emissions in the post 2020 pe-

riod.

As part of this Agreement, Trinidad and Tobago’s Nationally

Determined Contributions was derived from the Carbon

Reduction Strategy. T&T’s Carbon reduction strategy (CRS)

identified and assessed greenhouse gas mitigation options for

the major emitting sectors: Power Generation, Industry and

Transportation. Business as Usual (BAU) scenarios were

developed to 2040.

As per the Nationally Determined Contribution, T&T aims

to achieve a reduction objective in overall emissions by 15%

in these major sectors by 2030. The mitigation options also

included direct technology interventions such as Renewable

Energy and Energy Efficiency.

Energy efficiency and energy conservation are the first steps

to proper utilization of electrical energy. Energy conservation

is not the sole responsibility of any single entity, we are all

stakeholders. All citizens, in our homes and our workplaces,

can undertake energy efficiency practices. If we can success-

fully implement energy efficiency and conservation measures,

we can potentially achieve significant changes and positive

environmental impacts.

Sheena R. Gosine is the first

woman to graduate with a dis-tinction in Renewable Energy Technology from the Depart-

ment of Physics at the University of the West Indies, St Augustine. She has a unique background

both in the fields or Education and Sustainable Energy in Trini-dad and Tobago. She has over a

decade of experience having served as an educator: in Physics, Level 1 City and Guilds MEEET and a Masters Level Energy Efficiency Course. Sheena has also served as a Sustainable Energy Policy Analyst,

an Energy Auditor and an Energy Efficiency Con-sultant . Sheena has worked throughout the Carib-bean region; participating in numerous Energy Au-

dits at some of the largest hotels in the Caribbean Region.

She has been instrumental in providing technical

assistance to the newly institutionalized Renewable Energy Division of the Ministry of Energy and Energy Industries (MEEI) in Trinidad and Tobago. Sheena

was one of three individuals to serve on the secre-tariat to the Inter-Agency Committee for the Evalu-ation of Expressions of Interests (EOIs) for a Waste

to Energy (WtE) Facility at the Beetham Landfill. She continued to serve on the secretariat to the Inter-Agency for the Evaluation of Expressions of Inter-

ests (EOIs) for Renewable Energy (RE) Projects.


Hand-Held NPK Sensor

By: Dillon Boodoo

1.0 Objectives

The specific objectives of the project are as follows:

1. Select or build the necessary sensors and interface into the Human Machine Interface (HMI) for the Hydroponic

Experimental Automated Platform (HEAP) 2. Research models of plant growth for selected categories

of crops. 2. Research the correlation between vegetative indices and usable spectrums as they relate to nutrient concentrations

visible in the canopy.

2.0 Abstract

For the past fifteen (15) years, NASA has been working on using plants for human beings as a source of sustenance

with regards to long-term habitation in space. (Stuster, 1986) The Controlled Ecological Life Support System (CELSS) is one of the programs that addresses the prob-

lems faced with long-term human habitation. Currently, the systems being developed are hydroponic-based. However, these systems suffer from problems that results from nutri-

ent imbalances and deficiencies. (W.A. Hill) If a system can be developed that readily and accurately identifies incipient nutrient stress in plants, growth and development could be

vastly improved with regards to product quality. Since nu-trient deficiencies give rise to physical symptoms of degra-dation, the spectral responses and detection of these nutri-ents can provide useful insight into treating with deficien-

cies before they occur. There are currently remote-sensing methods used to detect the Nitrogen content in plants but very little information is present about the detection of

Phosphorus and Potassium, the two most important mac-ronutrients essential to plant growth after Nitrogen. (Chong Yen Mee) This project is geared towards the devel-

opment and implementation of control strategies to readily determine the Nitrogen (N), Phosphorus (P) and Potassium (K) levels in lettuce plants. Absorbance measurement cir-

cuits that make use of Light Emitting Diodes (LEDs) were used to detect the nutrient presence and the information was processed using the Arduino Bluno, an Ardunio Uno

with a built-in Bluetooth module. This information was then presented to the user via an Android application where

further diagnosis can be carried out. Although there were

many challenges faced, the sensors were successfully built, all major components were successfully integrated and rele-vant research was carried out on the models of plant

growth applicable to the scope of this project. 3.0 Models of Plant Growth—Green lab

The GreenLab Model is a type of Functional Structural

Plant Model (FSPM) (Zhao). It consists of two major com-ponents namely: 1. The Growth Engine Model 2. The 3-D Visualization Model

The Growth Engine Model is broken up into the Structural and Functional model. The Structural Model deals with the

plant’s organs, in particular, their production and develop-ment. The Functional Model deals with the eco-physiological aspect that is, how environmental factors in-

fluence plant growth and structure. From the Structural Model, intermediate data is set to be processed using 3-D Visualization where graphical data is produced as output.

From the Functional Model, simulation data is produced as output. (Zhao) This is seen below.

Figure 1.0: The overall workings of the GreenLab model, taken from https:/www.H_Hu_03.pdf

Upon first impression, plant growth may seem like a stag-nant process. However, by modelling plant organs and taking into consideration environmental factors, we can

optimize the growth and production rate of plants. The full model equations for the GreenLab Model can be seen in the next page.

For the following equations, the terms are as follows:

Equation for structure, that is, the number of organs in the current cycle that appears at a current time:

Where: up,q – Number of units that originate from the shoot at a time, t for a specified physiological age

bp,q– Number of auxiliary structures appearing at a cycle, t, for a specified physiological age

It should be noted that the sequences described can be either deterministic or stochastic.

Equation for plant demand at a specified cycle, n:

Equation for the biomass denoted to the organs:

Where: i - The organ age - expressed in cycles

Equation for total functioning leaf area S (n) at a specified cycle, n:

Where: – Leaf blade function at an age, j

– Blade age with

– Number of cycles before leaf deterioration

– Thickness of the leaf blade

Equation for the production at crop level:

By replacing S (n) in equation 5, with the S (n) expression as

seen in equation 4, we get the GreenLab production equa-

tion (Plant Growth Architecture and Production, n.d.):

The GreenLab Model has the advantage of being flexible in

that it has the ability to host many processes, allowing for a

range of applications. The detailed description of the plant’s

structure allows for visualization applications as well as pest

interaction. However, the model is difficult to calibrate and

validate. In addition, partitioning and biomass transport incur

high costs. Finally, predictive behaviours require multiple

experiments which is time-consuming.

4.0 Correlation between Vegetative Indices and Usable

Spectrums

This section deals with the spectral properties of Nitrogen

(N), Phosphorus (P) and Potassium (K) and the relevant

wavelengths at which these macronutrients can be detected.

A spectral reflectance index (SVI) gives a measure of the

green vegetation in a crop field (Spectral Vegetation Indices

(SVIs)). When data is collected via remote-sensing technolo-

gies, algebraic equations are then applied to further improve

on the results. Green vegetation has a unique spectral pat-

tern. This is seen at the Visible (VIS) and Near-Infrared (NIR)

wavelength range. A low reflectance value is seen on other

regions of the reflectance spectrum, which is why leaves ap-

pear green to human eyes (Spectral Vegetation Indices

(SVIs)). (SPECTRAL VEGETATION INDICES (SVIs), n.d.).

Most SVIs are determined by looking at the values in the

visible (VIS) and near-infrared (NIR) range. In the red region,

chlorophyll content can be detected (I. Filella, 2007) and the

NIR reflectance gives an idea of the mesophyll structure of

the plant. Two types of SVI used are the Ratio Vegetation

Index (RVI) and the Normalized Difference Vegetation Index

(NDVI) (SPECTRAL VEGETATION INDICES (SVIs), n.d.).

Ratio Vegetation Index (RVI)

This is given by the formula:

The Simple Ratio (SR) is close to 1 if the red and NIR bands

have similar reflectance values. High SR values are usually on

orders of 30.

Normalized Difference Vegetation Index (NDVI)

This is given by the formula:

For the NDVI, normalization is applied in an attempt to minimize

illumination levels. The NDVI range is from 1 to -1. A value of 0

indicates there is no vegetation while a value closest to 1 indicates a

high value of green leaf presence. This high value also indicates a

high biomass value.

4.10 Nitrogen Detection

The importance of Nitrogen (N) in plants cannot be over-

stated. Of all the nutrients essential to plant growth, Nitro-

gen is the most important as it facilitates proper plant

growth as well as the production of healthy fruits and vegeta-

bles (Phoslab Testing Laboratories, 2013). Nitrogen is an

essential component of amino acids, normally referred to as

the building blocks of plant proteins which is essential in the

development of plant tissues such as the cell membrane

(Geenway, 2016).

In addition, Nitrogen is a major component of vitamins and

aids in the production as well as usage of carbohydrates. The

most important function of Nitrogen in plants is its role in

the process of photosynthesis. N is an important component

in chlorophyll, the molecule which allows the absorption of

light energy to facilitate plant growth (Geenway, 2016). Since

N correlates directly with the chlorophyll content in the

leaves, we can determine a plant’s N level by monitoring the

chlorophyll presence. The wavelength at which the maximum

absorption of chlorophyll occurs is at 690 nm. This is re-

ferred to as the red-edge position and the strong absorption

comes as a result of the scattering of light in the leaf due to

the mesophyll structure. Although it was demonstrated that

total N content could be detected at both the VIS and NIR

wavelengths, the VIS bands were found to be the best pre-

diction of chlorophyll content.

Figure 2.0: Wavelength at which Nitrogen is absorbed in

plants.

4.20 Phosphorus Detection

Phosphorus (P) is another macronutrient essential for plant

growth as it is required for optimum growth and reproduc-

tion of plants (Functions of Phosphorus in Plants, 1999). The

range of total P concentration ranges from (0.1%-0.5%) in

agricultural crops (Soil Nutrient Management, n.d.). In addi-

tion, healthy P content improves the quality of fruits and

vegetables by improving crop maturity and allows for early

root formation and growth (Roles of the 16 Essential Nutri-

ents in Crop Development). P is also a major component

adenosine di-phosphate (ADP) and adenosine tri-phosphate

(ATP) which affects processes such as respiration, membrane

transport and biosynthesis. P stress levels leads to an in-

crease in a molecule known as anthocyanin which causes a

purple coloration in leaves (Pimstein, 2010). Therefore, by

monitoring the presence of anthocyanin, we can determine

the level of P stress experienced by the crop. Anthocyanin is

detected in the wavelength range of 400-550 nm (Mee). At

the early stage of plant growth, P-deficiency symptoms can

be detected at the NIR wavelengths of 730 nm and 930 nm

(Bansal, Field Crops Research, 2010). It is at the V6 stage

(wavelengths around 440-445 nm), anthocyanin can be de-

tected (Pimstein, 2010).

Figure 3.0: The wavelength at which Phosphorus is ab-

sorbed in plants,.

4.30 Phosphorus Detection

Potassium (K) is considered by many to be the most essen-

tial nutrient needed by a plant after Nitrogen. Since K is not

used in structural makeup of pigments and molecules essen-

tial to plant growth, it is difficult to detect by looking at the

absorption wavelengths of these pigments needed by the

plant. K prevents the plant from wilting through maintenance

of the plant’s turgor pressure. A healthy K level results in the

proper functioning of the stomata, which allows water va-

pour, Carbon Dioxide and Oxygen to leave the plant

(Functions of Potassium in Plants, 1998). These gases are

produced as a result of photosynthesis in the plant. In addi-

tion, healthy levels of K allow for disease resistance and im-

proves the quality of seeds and fruits. In order to determine

the K level in the plant, we must be able to effectively meas-

ure the K+ ions in the plant. Potassium concentration in

plants is done through absorption of the K+ ion. This is de-

tected at a wavelength of 517 nm which lies in the green

portion of the visible spectrum (Sodium and Potassium Indi-

cators and ionophores, n.d.). Although excitation can occur

at 488 nm, 517 nm represents the wavelength where the

maximum excitation occurs. Although the monitoring of sto-

matal opening can be done with red and blue light (Assmann,

1999), using green light gives the best indication of stomatal

activity, which can be used to detect the K level in plants. In

addition, green light is also preferred to red and blue light for

stomatal activity as the stomatal pores are located deeper

within the leaf’s structure and green light penetrates deeper

than red or blue light.

5.0 System Overview

•Develop absorbance measurement circuits

•Design switching configuration for the above circuits

•Automate the acquisition of results using a microcon-troller

•Present the results to the user via an Android applica-tion

5.10 Absorbance Measurement Circuits

Absorbance (A) is a substance’s ability to absorb light or

electromagnetic radiation at a specified wavelength

(Absorbance Definition, n.d.). Research shows at different

wavelengths, we are able to determine the Nitrogen (N),

Phosphorus (P) and Potassium (K) level in the plant. For the

Absorbance measurement circuits, light sources at the speci-

fied wavelengths were used to determine the nutrient con-

tent in the plant. The light sources used were Light Emitting

Diodes (LEDs).

On a global ranking scale, LEDs are third (3rd) when it comes

to energy conversion efficiency, that is, the conversion of

electricity to light. In addition, they cover a broad range of

wavelengths and are continuously increasing in emission in-

tensity. Also, their small size, minimal cost as well as stability

with regards to light fluctuation made them ideal light

sources to be used in this project. Typically, for light sensing

devices, LEDs are used together with photodiodes. The LED

acts as the light source emitter while the photodiode acts as

the photo-sensor. However, it was suggested that two LEDs

of similar wavelength can be used for sensing by using one

LED in forward-bias and the other in reverse-bias

(Dasgupta). In this configuration, the LED in forward bias

acts as the light source while the LED in reverse bias acts as

the photo-sensor. Since LEDs are known to be more sensi-

tive to the same wavelength that it emits (Shin, 2013) when

compared to photodiodes, this set-up was chosen for this

project. The figure below shows the Multisim circuit diagram

for the Absorbance measuring circuit.

Figure 4.0: The Multisim design Absorbance measuring cir-

cuit

As seen above, the forward-biased LED acts as the emitter

while the reverse-biased LED acts as the receiver. Light from

the emitter LED illuminates the emitting chip of the receiver

LED. When this occurs, a small amount of current is pro-

duced. The current produced is then passed through an op-

erational amplifier to amplify the photocurrent on the receiv-

er LED. This circuit amplifies the current produced by 106, as

seen by the 1 MΩ resistor. This is due to the photocurrent

produced, which is usually in the range of Nano Amperes

(nA). Since this current is minute in nature, a low noise JFET-

Input operational amplifier must be used to detect this cur-

rent. Therefore, the TLO71CP is most appropriate for use in

this circuit. This circuit was initially designed on a bread-

board and can be seen below (Figure 5). Following this is a

Multisim design (Figure 18) showing the operation of the

amplification using the TLO71 and the 1 MΩ resistor in the

current-to-voltage converter.

Absorbance Calculation

Since the voltage at the output is directly proportional to the

light received by the emitter LED, we can modify Beer’s Law

5.20 Methods of Switching

Relays and transistors were the two methods explored in

determining the switching configuration. In terms of the

switching speed, transistors are much quicker than relays,

taking a few picoseconds when compared to the 50 millisec-

onds taken by the relay (Relay vs Transistor?, n.d.). In addi-

tion, electromagnetic problems can occur when using relays

while transistors emit little to no electromagnetic interfer-

ence. When in the “on” state, relays consume a lot of cur-

rent while transistors do not. Relays also need a greater

switching voltage (around 6 Volts) when compared to the

transistor (0.5 Volts or less). Relays are often used for heavi-

er loads for example 1.5 Amperes or anything above 18

Volts. For these reasons, the transistor configuration was

chosen as the means of switching.

Figure 5.0: Absorbance circuit with switching configuration

Printed Circuit Board (PCB) Design

The design for the sensors were done with the goal of mak-

ing the system portable so that plant health could be deter-

mined over a wide range of environments. The initial design

on the breadboard was successful but the breadboard itself

was bulky as only a portion of the board was being used for

the circuits. In an attempt to save on space, a PCB design

was done using the Autodesk Eagle software. The schematic

for the circuit was first built followed by the connection of

copper lines in the circuits to create the finished product.

This can be seen below.:

Figure 6.0: The layout of the finished PCB design

5.40 The Microcontroller

From the Absorbance measurement circuits, the manual

method of collecting results using the multimeter and calcu-

lator was time-consuming at times and the threat of human

errors when recording these values was imminent. These

materials may not be available in a hydroponic system, when

accurate determination of plant health is of paramount im-

portance. To automate the acquisition of results, a micro-

controller was selected for this project. The microcontrol-

lers that were considered included the Arduino Nano and

Raspberry Pi. The project scope was examined to determine

which would be more suitable. In this project, the microcon-

troller was used for switching between the different sensing

circuits and for collecting the Absorbance values. Due to the

simplicity and repetitive nature of these tasks, the Arduino

Nano was selected. One instance where the Raspberry Pi

would have been preferred is if there were more complex

tasks with intense calculations. Thus, the Arduino Nano was

selected. However, to further improve on the delivery of

results, it was concluded that wireless communication with

the user would be the best method to obtain results in a

variety of environments. As a result, Bluetooth technology

was examined to allow this communication. The HC-O5 is a

Bluetooth module that can be used with the Arduino Nano

to communicate with the user wirelessly. However, there

would need to be connection with the Bluetooth module

which would mean more circuitry into the system. To avoid

this, the Arduino Bluno was selected. The Arduino Bluno

Nano is essentially an Arduino Nano with a built-in Blue-

tooth module to allow wireless transfer of information. As a

result, the Bluno Nano was selected as the microcontroller

for this project.

Figure 7.0: Image of the Arduino Bluno Nano, taken from

https://thepihut.com/products/bluno-nano-an-arduino-nano-

with-bluetooth-4-0

5.40 The Android Application

Android Studio was chosen due to its simplistic nature when

accessing native components such as the Bluetooth technolo-

gy from the Bluno Nano. Android Studio has a rich layout

editor that allows you to preview layouts on screen configu-

rations. In addition, there is adequate support and the soft-

ware allows for faster design and testing. Alternatives to An-

droid Studio included means of hybrid development which

would make writing code to the Bluno difficult because of

the levels of abstractions from the native components. An

example of hybrid development would be the creation of a

mobile responsive application, with the ability to work on

both Android and iOS devices. In order to create the inter-

face, a Bluetooth application to read the values from the Blu-

no Nano was modified to include buttons to store the values

in a database. The basic opening screen as well as the

“Nutrient History” page are shown below. Following this is a

figure which shows interconnection of all components for

nutrient detection.

Figure 8.0: The opening page of the application

Figure 9.0: The Nutrient History page of the application

Figure 10.0: Interconnection of all sub-components

6.0 Discussion

The sensing circuits designed were able to give Absorbance

values to denote the nutrient content in the lettuce leaf. It

was noted that of the three (3) circuits, Nitrogen gave the

most appropriate results when a healthy and unhealthy leaf

was placed in the circuit. For the healthy leaf, a relatively

high value was recorded which meant chlorophyll, a pigment,

absorbed the light at this wavelength (approximately 690

nm). In addition, an unhealthy leaf gave a low Absorbance

value which meant that the chlorophyll “a” pigment was not

present in a healthy amount to give an appropriate Absorb-

ance value. In the research conducted, experiments acknowl-

edged the fact that a healthy chlorophyll a concentration

correlates directly with a healthy N level. Similar responses

were seen with P and K detection. The circuit values ac-

quired further cemented this fact.

The Hoagland’s solution is a hydroponic nutrient solution

that contains the appropriate concentrations of the major

nutrients essential to plant growth. This can be extremely

useful in the design of sensors to determine plant health. By

monitoring the nutrient content of the plant via the sensors,

we can determine exactly how much of a nutrient a plant

requires or does not require. By doing this, we are now able

to effectively allocate nutrient resource to the plant whilst

improving the natural growth of the plant. If a known con-

centration of a particular nutrient is known and the sensors

are applied it, the absorbance value can be denoted (solely

for Nitrogen at this point). Using interpolation, we can now

begin to generate a calibration curve that follows the equa-

tion:

Once this calibration curve is developed, we can now begin

to calculate the absorbance level of a nutrient at a particular

concentration. Through this method, we are also able to

better diagnose the plant with regards to nutrient allocation.

The chlorophyll “a” pigment was the only major pigment

targeted in this project. A better representation of the health

level of the plant may be able to be determined by monitor-

ing the major pigments the plant requires rather than the

actual nutrient present in the plant. On many occasions, it is

the presence of a particular pigment that leads to the deter-

mination of the nutrient content. For example, the chloro-

phyll “a” to Nitrogen concentration. If we design sensors

that target the pigment, we will be better able to diagnose

the plant using the Hoagland’s solution as well as be able to

generate calibration curves which improves the overall accu-

racy of plant health determination.

7.0 Conclusion

When compared to the existing methods used for Nitrogen

detection, proper application of the NPK sensor will yield

more accurate results in a shorter period of time. As there

are currently no existing methods of Phosphorus and Potas-

sium detection, the sensor is also preferred. Nitrogen is used

in preference to all other macronutrients as it gives an over-

all indication of plant health. However, one must not omit

the other major macronutrients and its effect on plant

health.

Dillon Boodoo holds a B.Sc. (Hons)

in Electrical and Computer Engi-neering from the

UWI, St. Augustine with a Major in Control Systems.

His professional career began as an Operations Ac-count Manager at

Ramps Logistics, then to an Associ-ate Professional at

the UWI followed by an Engineering Trainee at Qual-

itech Machining Services Limited. He is currently a Graduate Trainee at Massy Wood in the Instrumenta-tion and Controls Department and is involved with

Quality Control/Quality Assurance (QA/QC), com-missioning and engineering design. Winner of a nation-al scholarship (2014), Dillon is a private tutor at the

CSEC level and an avid member of the Alumni Associ-ation at his alma mater. In addition, he enjoys going to the gym, playing a myriad of sports including cricket

and football and is extremely passionate about the rocky journey of the West Indies cricket team and

Chelsea FC.


ARTICLE REFERENCES

PROCESS—Design and Selection of Choke Valves Part 1I

• Ahmed A.M Elgibal, Ibrahim S.Nashawi. ‘’Prediction of Two-Phase Flow Through Chokes of Middle East Oil Wells.’’ 1996.

• Alireza Bahadori. ‘’Natural Gas Processing.” 2014.

• Ana Paula Meneguelo, Daniel Da Cunha Ribeiro, Margotto, Romulo, Jeferson Cunha, Reginaldo Miranda, , Ully Misse Moreno Benedito, and. "Chokes in Series Provide Safe Testing Operations in Wells with Abrasive Solids." OTC Brasil, 2017. doi:10.4043/28198-ms.

• Arashi Ajayi and Konopczynski, Michael, "Design of Intelligent Well Downhole Valves for Adjustable Flow Control." SPE Annual Technical Conference and Exhibition, 2004. doi:10.2118/90664-ms.

• Ayoola, Olakunle T., Wendell Wc Delandro, and Ali M. Muslim. "Detecting Production Choke Wear in High Rate Dry Gas Wells using Graphical Trending of Production Parameters: An Offshore Saudi Arabia Gas Field Case Study." SPE Annual Technical Con-ference and Exhibition, 2016. doi:10.2118/182144-ms

• Barton, Neil, Mike Lewis, and Paul Emmerson. "CFD Erosion Prediction in Gas-Liquid-Sand Flow." SPE International Oilfield Corrosion Conference and Exhibition, 2016. doi:10.2118/179926-ms.

• Cain, L.l. "Unique Well Control Choke: Design Objectives vs. Commercial Field Performance." SPE/IADC Drilling Conference, 1987. doi:10.2118/16132-ms.

• Changzhi Lin, Li, Guomei, Yueshe Wang, Renyang He, Xuewen Cao, and Tao Meng. "Numerical simulation of predicting and re-ducing solid particle erosion of solid-liquid two-phase flow in a choke." Petroleum Science 6, no. 1 (2009): 91-97. doi:10.1007/s12182-009-0017-9.

• Ehsan Khamehchi, Ebrahim Reisi, “Sand Production Prediction Using Ratio of Shear Modulus to Bulk Compressibility (case

study).’’ 2015.

• Emad Gharaibah, John D. Friedemann, Paggiaro, Ricardo, and Yongli Zhang. "Prediction of Sand Erosion in Choke Valves - CFD Model Development and Validation against Experiment." OTC Brasil, 2013. doi:10.4043/24271-ms.

• Grant, Lee. "Montney Unconventional Gas Play: Managing Choke Wear Using Flow Coefficient Diagnostics." SPE/CSUR Uncon-ventional Resources Conference, 2015. doi:10.2118/175992-ms.

• Ioana Cristina Grigorescu1. “Erosion-Corrosion Failures in Wellhead Chokes.” Universidad Simon Bolivar, Sartenejas, Baruta, Ca-

racas 1080. Venezuela. Nace Corrosion Conference & Expo 011.

• Master Flo Valve Inc. 2014a. P2E Choke Valve Detail. http://www.masterflo.com/products/chokevalves/p2-e-hun-10000

• Master Flo Valve Inc. 2014b. P3E Choke Valve Detail. http://www.masterflo.com/products/chokevalves/p3-e-hun-10000

• Naeim Nouri Samie. "Practical Engineering Management of Offshore Oil and Gas Platforms." (2016) Google Books. Accessed Feb-ruary 07, 2018. https://books.google.tt/books?id=0XU1CwAAQBAJ&pg=PA212&lpg=PA212&dq=systems%2Band%2Bequipment%2Bfor%2Boffshore%2Bplatform%2Bdesign%2Bchapter%2B3&source=bl&ots=rE815KQ0AW&sig=N0BhfXo8At0ZMj2T-61rR7xYZag&hl=en&sa=X&ved=0ahUKEwjXh8qXoJXZAhURy1MKHZycBnoQ6AEILjAC#v=onepage&q=systems%20and%20equipment%20for%20offshore%20platform%20design%20chapter%203&f=false.

• Saeed, Abdullah J. Al, Salah A. Al Mousa, Mohammed A. Al Ajmi, and Martin Odonnell. "Successful Installation of Multistage Choke Valve Technology in Water Flowlines to Reduce High Pressure Drop across Choke Valves." SPE Saudi Arabia Section Annu-al Technical Symposium and Exhibition, 2015. doi:10.2118/177988-ms.

• S. Gorini, A. Maliardi, eni spa, S. Malavasi, G. V. Messa. Politecnico di Milano University. “Enhanced Erosion Preduction for Xtree Valves Lifetime Estimation.’’ OMC Italy, 2017.

• Sherik, Abdelmounam Mustafa. ‘’Trends in oil and gas corrosion research and technologies: production and transmission’’. Duxford, UK: Woodhead Publishing, 2017.

• Tawancy, H.m., and Luai M. Alhems. "Damage analysis of choke bean used in an oil–gas well." Case Studies in Engineering Failure Analysis7 (2016): 56-64. doi:10.1016/j.csefa.2016.08.001.


ARTICLE REFERENCES

MECHANICAL— Automated Identification of Vehicular Accidents from Acoustic Signals Using Artificial Neural Net-

works

• Cafiso, S., Di Graziano, A., and Pappalardo, G. In-vehicle stereo vision system for identification of traffic conflicts between bus and

pedestrian Journal of Traffic and Transportation Engineering, Vol.4, No.1, pp. 3-13.

• Dadashova, B., Arenas-Ramirez, B., Mira-McWilliams, J., and Aparicio-Izquierdo, F. (2016), “Methodological development for selec-

tion of significant predictors explaining fata road accidents”, Accident Analysis and Prevention, Vol.90, pp.82-94.

• de Ona, J., Lopez, G., Mujalli, R., and Calvo, F.J. (2013), “Analysis of traffic accidents on rural highways using Latent Class Clustering

and Bayesian Networks”, Accident Analysis and Prevention, Vol51, pp.1-10.

• Delen, D., Sharda, R., and Bessonov, M. (2006), “Identifying significant predictors of injury severity in traffic accidents using a series

of artificial neural networks”, Accident Analysis and Prevention, Vol.38, pp.434-444.

• Evtiukov, S., Kurakina, E., Lukinskiy, V., and Ushakov, A. (2017), “Methods of accident reconstruction and investigation given the

parameters of vehicle condition and road environment”, Transportation research Procedia, Vol. 20, pp. 185-192.

• George, J., Cyril, A., Koshy, B. I., and Mary, L. (2013a), “Exploring sound signature for vehicle detection and classification using

ANN”, International Journal on Soft Computing, Vo4, No.2, pp. 29-36.

• George, J., Mary, L., and Riyas, K. (2013b), “Vehicle detection and classification from acoustic signal using ANN and KNN”, Pro-

ceedings of the International Conference on Control Communication and Computing, Thiruvananthapuram, India, Decem-

ber,pp.436-439. DOI: 10.1109/ICCC.2013.6731694.

• Kononen, D.W., Flannagan, C.A.A., and Wang, S.C. (2011), “Identification and validation of a logistic regression model for predict-

ing serious injuries associated with motor vehicle crashes”, Accident Analysis and Prevention, Vol. 43, pp. 112-122.

• Li, M., Wang, X.H., and Shi, K. (2017), “Traffic conflict identification technology of vehicle intersection based on vehicle video tra-

jectory extraction”, Procedia Computer Science, Vol.109, pp.963-968.

• Mujali, R.O., and de Ona, J. (2011), “A method for simplifying the analysis of traffic accidents injury severity on two-lane highways

using Bayesian networks”, Journal of Safety Research, Vol. 42, pp.317-326.

• Ozgunduz, E., Turkmen, I., Senturk, T, Elif Karsligil, M., and Gokhan Yavuz, A. (2010), “Vehicle identification using acoustic and seis-

mic signals”, Proceedings of the IEEE Signal processing and Communications Applications Conference (SIU), Diyarbakir, Turkey,

April, pp.941 944 DOI: 10.1109/SIU.2010.5652112.

• WHO (2017), Global Health Observatory Data, World Health Organisation, Available from the website: http://www.who.int/gho/

road_safety/mortality/en/ Accessed on 10 November 2017.

• Wu, H., Siegel, M., and Khosla, P. (1999), Vehicle sound signature recognition by frequency vector principal component analysis

IEEE Instrumentation and Measurement Technology Conference, Vol.48, No.5, October, pp. 429-434.

MECHANICAL— Bioplastics and Environmental Sustainability: Some Thoughts

• Arora, N.K., Fatima, T., Mishra, I., Verma, M., Mishra, J and Mishra, V. (2018) Environmental sustainability: challenges and viable

solutions, Environmental Sustainability, Vol. 1, pp. 309-340, DOI: https://doi.org/10.1007/s42398-018-00038-w

• Babu, R.P., O'Connor, K. and Seeram, R. (2013) Current progress on bio-based polymers and their future trends, Progress in Bio-

materials, Vol. 2, No. 8. DOI: https://doi.org/10.1186/2194-0517-2-8


ARTICLE REFERENCES

MECHANICAL — Bioplastics and Environmental Sustainability: Some Thoughts

• Canelo, A. (2018) New Technology to Dismantle the Largest Plastic Spillway in the Pacific Ocean, The Costa Rican News [Online]

Available at: https://thecostaricanews.com/new-technology-to-dismantle-the-largest-plastic-spillway-in-the-pacific-ocean/ Accessed

on March 20, 2019.

• Echo Instruments (2016) BIOPLASTIC DEGRADATION [Online] Available at: http://www.echoinstruments.eu/applications/

bioplastic-degradation/ Accessed on March 20, 2019.

• Goodland, R. (1995) The Concept of Environmental Sustainability, Annual Review of Ecology and Systematics, Vol. 26, pp. 1-24,

DOI: https://www.jstor.org/stable/2097196.

• Government of the Republic of Trinidad and Tobago (2015) National Waste Recycling Policy 2015 [Online] Available at: http://

www.planning.gov.tt/sites/default/files/WASTE%20RECYCLING%20POLICY%202015%20Final.pdf Accessed on March 11, 2019.

• Lambert, S. and Wagner, M. (2017) Environmental performance of bio-based and biodegradable plastics: the road ahead, Chemical

Society Reviews, Vol. 46, pp. 6855-6871 DOI: https://doi.org/10.1039/C7CS00149E.

• National Oceanic and Atmospheric Administration Marine Debris Program (2018) Approximate Time it takes for Garbage to De-compose in the Environment [Online] Available at: https://www.des.nh.gov/organization/divisions/water/wmb/coastal/trash/

documents/marine_debris.pdf Accessed on March 11, 2019.

• PLASTICS (2018) Position Paper on Degradable Additives [online] Available at: https://www.plasticsindustry.org/sites/default/

files/2018%20PLASTICS%20-%20Position%20Paper%20on%20Degradable%20Additives.pdf Accessed on March 18, 2019.

• Selke, S., Auras, R., Nguyen, T.A., Castro Aguirre, E., Cheruvathur, R. and Liu, Y. (2015) Evaluation of Biodegradation-Promoting

Additives for Plastics, Environmental Science & Technology, Vol. 49, No. 6, pp. 3769-3777 DOI: https://doi.org/10.1021/es504258u.

• Shah, M.M. (2008) Sustainable Development, Encyclopedia of Ecology, Reference Module in Earth Systems and Environmental Sci-

ences, pp. 3443-3446 DOI: https://doi.org/10.1016/B978-008045405-4.00633-9.

CIVIL / ENVIRONMENTAL—Assessing The Sensitivity Of The East Coast of Trinidad To Oil Spills

• Castanedo, S., J. A. Juanes, R. Medina, A. Puente, F. Fernandez, M. Olabarrieta, and C. Pombo. 2009. "Oil spill vulnerability assess-

ment integrating physical, biological and socio-economical aspects: application to the Cantabrian coast (Bay of Biscay, Spain)." J Envi-

ron Manage 91 (1):149-59. doi: 10.1016/j.jenvman.2009.07.013.

• Center for Biological Diversity. 2017. "Dispersants." Center for Biological Diversity Accessed 07/05/17. http://

www.biologicaldiversity.org/programs/public_lands/energy/dirty_energy_development/oil_and_gas/gulf_oil_spill/dispersants.html.

• Eckhart, Karen L. 2010. Sea Turtle Recovery Action Plan for the Republic of Trinidad and Tobago.

• Environmental Management Authority. 2005. The Administrative Record for the Environmentally Sensitive Area: Nariva Swamp

Managed Resource Protected Area. Institue of Marine Affairs.

• Environmental Management Authority. 2011. Guidebook for Hydrodynamic Considerations in EIA applications-Appendix B- Coastal

Environments. Environmental Management Authority.

• Georges, Cicely. 1983. A Coastal Classification for Trinidad. edited by Institute of Marine Affairs.

• Institute of Marine Affairs. 2013. A Guide to the Beaches and Bays of Trinidad and Tobago. Institute of Marine Affairs.

• Juman, R.A , and D Ramsewak. 2010. "Status of Mangrove Forests in Trinidad and Tobago." IMA Research report.


ARTICLE REFERENCES

MECHANICAL — Bioplastics and Environmental Sustainability: Some Thoughts

• Canelo, A. (2018) New Technology to Dismantle the Largest Plastic Spillway in the Pacific Ocean, The Costa Rican News [Online]

Available at: https://thecostaricanews.com/new-technology-to-dismantle-the-largest-plastic-spillway-in-the-pacific-ocean/ Accessed

on March 20, 2019.

• Echo Instruments (2016) BIOPLASTIC DEGRADATION [Online] Available at: http://www.echoinstruments.eu/applications/

bioplastic-degradation/ Accessed on March 20, 2019.

• Goodland, R. (1995) The Concept of Environmental Sustainability, Annual Review of Ecology and Systematics, Vol. 26, pp. 1-24,

DOI: https://www.jstor.org/stable/2097196.

• Government of the Republic of Trinidad and Tobago (2015) National Waste Recycling Policy 2015 [Online] Available at: http://

www.planning.gov.tt/sites/default/files/WASTE%20RECYCLING%20POLICY%202015%20Final.pdf Accessed on March 11, 2019.

• Lambert, S. and Wagner, M. (2017) Environmental performance of bio-based and biodegradable plastics: the road ahead, Chemical

Society Reviews, Vol. 46, pp. 6855-6871 DOI: https://doi.org/10.1039/C7CS00149E.

• National Oceanic and Atmospheric Administration Marine Debris Program (2018) Approximate Time it takes for Garbage to De-compose in the Environment [Online] Available at: https://www.des.nh.gov/organization/divisions/water/wmb/coastal/trash/

documents/marine_debris.pdf Accessed on March 11, 2019.

• PLASTICS (2018) Position Paper on Degradable Additives [online] Available at: https://www.plasticsindustry.org/sites/default/

files/2018%20PLASTICS%20-%20Position%20Paper%20on%20Degradable%20Additives.pdf Accessed on March 18, 2019.

• Selke, S., Auras, R., Nguyen, T.A., Castro Aguirre, E., Cheruvathur, R. and Liu, Y. (2015) Evaluation of Biodegradation-Promoting

Additives for Plastics, Environmental Science & Technology, Vol. 49, No. 6, pp. 3769-3777 DOI: https://doi.org/10.1021/es504258u.

• Shah, M.M. (2008) Sustainable Development, Encyclopedia of Ecology, Reference Module in Earth Systems and Environmental Sci-

ences, pp. 3443-3446 DOI: https://doi.org/10.1016/B978-008045405-4.00633-9.


• Castanedo, S., J. A. Juanes, R. Medina, A. Puente, F. Fernandez, M. Olabarrieta, and C. Pombo. 2009. "Oil spill vulnerability assess-

ment integrating physical, biological and socio-economical aspects: application to the Cantabrian coast (Bay of Biscay, Spain)." J Envi-

ron Manage 91 (1):149-59. doi: 10.1016/j.jenvman.2009.07.013.

• Center for Biological Diversity. 2017. "Dispersants." Center for Biological Diversity Accessed 07/05/17. http://

www.biologicaldiversity.org/programs/public_lands/energy/dirty_energy_development/oil_and_gas/gulf_oil_spill/dispersants.html.

• Eckhart, Karen L. 2010. Sea Turtle Recovery Action Plan for the Republic of Trinidad and Tobago.

• Environmental Management Authority. 2005. The Administrative Record for the Environmentally Sensitive Area: Nariva Swamp

Managed Resource Protected Area. Institute of Marine Affairs.

• Environmental Management Authority. 2011. Guidebook for Hydrodynamic Considerations in EIA applications-Appendix B- Coastal

Environments. Environmental Management Authority.

• Georges, Cicely. 1983. A Coastal Classification for Trinidad. edited by Institute of Marine Affairs.

• Institute of Marine Affairs. 2013. A Guide to the Beaches and Bays of Trinidad and Tobago. Institute of Marine Affairs.

• Juman, R.A , and D Ramsewak. 2010. "Status of Mangrove Forests in Trinidad and Tobago." IMA Research report.


ARTICLE REFERENCES


• Ministry of Energy and Energy Affairs. 2013. National Oil Spill Contingency Plan of Trinidad and Tobago.

• NOAA. 2002. Environmental Sensitivity Index Guidelines Version 3.0. In NOAA Technical Memorandum NOS OR&R 11 National

Oceanic and Atmospheric Administration.

• NOAA. 2014a. "How does oil impact marine life?". National Ocean Service Accessed 01/05/17. http://oceanservice.noaa.gov/facts/

oilimpacts.html.

• NOAA. 2014b. Oil Spills in Mangroves: Planning and Response Considerations. National Oceanic and Atmospheric Administration.

• NOAA. 2014c. "What is an environmental sensitivity index map?". National Oceanic and Atmospheric Administration Accessed

26/04/17. http://oceanservice.noaa.gov/facts/esimap.html.

• Pincinato, F. L, P. S Riedel, and J. C. C Milanelli. 2009. "Modelling an expert GIS system based on knowledge to evaluate oil spill

environmental sensitivity." Ocean & Coastal Management 52 (9):479-486. doi: 10.1016/j.ocecoaman.2009.08.003.

• Snyder, Richard A., Alexandra Vestal, Christina Welch, Gracie Barnes, Robert Pelot, Melissa Ederington-Hagy, and Fredrick Hi-leman. 2014. "Study Finds Clams are Oil Indicator Species for Gulf of Mexico Surf Zones." Gulf of Mexico Research Initiative Ac-

cessed 07/05/17. http://gulfresearchinitiative.org/study-finds-clams-oil-indicator-species-gulf-mexico-surf-zones/.

• The United Kingdom Hydrographic Office Admiraility EasyTide. 2017. "Predict - Select port." Accessed 7/11/17. http://

www.ukho.gov.uk/Easytide/easytide/SelectPort.aspx.

• Wieczorek, Arthur, Dimas Dias-Brito, and João Carlos Carvalho Milanelli. 2007. "Mapping oil spill environmental sensitivity in Car-

doso Island State Park and surroundings areas, São Paulo, Brazil." Ocean & Coastal Management 50 (11-12):872-886. doi: 10.1016/

j.ocecoaman.2007.04.007.

CIVIL / ENVIRONMENTAL—A Sustainable Solution for Red Mud in the Caribbean

• Google search. https://rusal.ru/en/about/11/

• Google Search. http://nepa.gov.jm/LBS-Workshop/Waste%20from%20Bauxite%20and%20Alumina%20Industry%20-%20JBI.pdf. Last

Viewed 6-2-18.

• Hua, Yumei., Kate V. Heal and Wolfgang Friesl-Hanl. 2017. “The use of red mud as an immobiliser for metal/metalloid-

contaminated soil: A review.” Journal of Hazardous Materials. 325. 17-30 DOI 10.1016/j.jhazmat.2016.11.073.

• Ribeiro, D.V., A.S. Silva, J.A. Labrincha, and M.R. Morelli. 2013. “Rheological properties and hydration behaviour of Portland cement

mortars containing calcined red mud.” Canadian Journal of Civil Engineering 40: 557-566 DOI: 10.1139/cjce-2012-0230.

• Traoré D. L., Traoré S. and, Diakité S. 2014. “Bauxite Industry in Guinea and Value Opportunities of the Resulting Red Mud as

Residue for Chemical and Civil Engineering Purposes.” Journal of Civil Engineering Research, 4(1): 14-24 DOI: 10.5923/

j.jce.20140401.03.


ARTICLE REFERENCES

CIVIL / ENVIRONMENTAL— KMA in-plant Cold Recycling Technology in Road Construction and Rehabilitation in

Trinidad and Tobago

• Wirtgen GmbH 2012. Wirtgen Cold Recycling Technology, 1st edition Germany: Wirtgen Group.

ELECTRICAL - The “Human” case for Energy Efficiency in Trinidad and Tobago

• Hofmeister, B. (2010). Bridging the Gap: Using Social Psychology to Design Market Interventions to Overcome the Energy Efficien-

cy Gap in Residential Energy Markets. Southeastern Environmental Journal(19), 7-8.

• IEA. (2014). Energy Security. Retrieved October 10, 2014, from http://www.iea.org/topics/energy security/subtopics/

whatisenergysecurity/

• IEA;OECD. (2013). Secure and Efficient Electricity Supply During the Transition to Low Carbon Power Systems. Retrieved October

7, 2014, from Publications: http://www.iea.org/publications/freepublications/publication/secureandefficientelectricitysupply.pdf

• International Energy Agency. (2014). Key World Energy Statistics 2014. Retrieved October 7, 2014, from Publications: http://

www.iea.org/publications/freepublications/publication/KeyWorld2014.pdf

• Leung, C. S., & Meisen, P. (2007, April 24). How electricity consumption affects social and economic development by comparing low, medium and high human development countries. Retrieved October 17, 2014, from Global Energy Institute Network: http://

www.geni.org/globalenergy/issues/global/qualityoflife/HDI-vs-Electricity-Consumption-2005-07-18.pdf

• Manickchand, N. M. (2011). Renewable energy development in T&T Exploring scenarios for the deployment of solar photovoltaic

systems. Sweden: IIIEE, Lund University.

• McGuire, G. (2007). Competition in Energy Markets: Trinidad and Tobago. Calgary: Latin American Energy Organization.

• MEEA. (2014, September 16). Energy Ministry Always in Open Discussion with Point Lisas Energy Companies. Retrieved October

16, 2014, from http://www.energy.gov.tt/energy-ministry-always-in-open-discussion-with-point-lisas-energy-companies/

• Methanex. (2014, August 26). METHANEX ANTICIPATES LOWER TRINIDAD GAS SUPPLY IN THE SECOND HALF OF 2014.

Retrieved October 16, 2014, from https://www.methanex.com/news/methanex-anticipates-lower-trinidad-gas-supply-second-half-

2014

• Ministry of Energy and Energy Industries. (2019). LNG Exports.

• Newspower. (2014, November 27). T&TEC Update. Retrieved December 2, 2014, from http://news.power102fm.com/ttec-update-

26316

• OLADE, L. A. (2012, November). Energy Economic Information System Energy Statistics, 22.

• Parliament of the Government of Trinidad and Tobago. (2013). Fifteenth Report of the Joint Select Committee on Ministries, Statu-

tory Authorities and State Enterprises on the Administrations and Operations of T&TEC. Port of Spain: GOTT.

• Regulated Industries Commission. (2008). Regulated Industries Commission. Retrieved November 2, 2013, from http://

www.ric.org.tt/cms/content/view/56/49/

• RIC. (2003). Shedding Light on the Regulated Industries Commission's rate review process. Port of Spain: RIC.

• RIC. (2009). Summary of Electricity Rates. Retrieved December 12, 2014, from Trinidad and Tobago Electricity Commission:

https://ttec.co.tt/services/tariffs/images/TTECRatesSummaryEffective1Sept2009.gif


ARTICLE REFERENCES

ELECTRICAL—The “Human” case for Energy Efficiency in Trinidad and Tobago

• Stabroek News. (2014, September 15). Proman set to acquire CLICO Methanol Holdings. Retrieved November 21, 2014, from

http://www.stabroeknews.com/2014/news/regional/09/15/proman-set-acquire-clicos-methanol-holdings/

• T&TEC. (2010). T&TEC Business Plan 2011-2016. Port of Spain: T&TEC.

• The Energy Chamber of Trinidad and Tobago. (2017, May 23). How much electricity do we use in our homes in T&T. Retrieved

from Energy Chamber of Trinidad and Tobago: https://energynow.tt/blog/how-much-electricity-do-we-use-in-our-homes-in-tt

• Ugursal, V. I. (2011). Energy use and changing energy policies of Trinidad and Tobago. Energy Policy 39, 5791–5794.

• UNDP. (2011). United Nations Development Programme. Retrieved November 1, 2013, from United Nations Development Pro-

gramme Reports: http://hdr.undp.org/en/statistics/hdi/

• UNFCC. (2015). What is the Paris Agreement? Retrieved 2019, from https://unfccc.int/process-and-meetings/the-paris-agreement/

what-is-the-paris-agreement

• United Nations. (2005). 2002 Energy Statistics Yearbook. New York: United Nations Publications.

• United Nations Development Programme. (2019). Human development Reports. Retrieved October 17, 2014, from http://

hdr.undp.org/sites/all/themes/hdr_theme/country-notes/TTO.pdf

• United Nations Environment Programme. (2008). Reforming Energy Subsidies Opportunities to Contribute to the Climate Change

Agenda. UNEP Division of Technology, Industry and Economics.

• Williams, C. (2014, September 3). Oil and Gas Journal. Retrieved November 21, 2014, from Ryder Scott: Trinidad and Tobago gas

reserves fell in 2013: http://www.ogj.com/articles/2014/09/ryder-scott-trinidad-and-tobago-s-gas-reserves-fell-in-2013.html

• Williams, C. (2014, October 12). T&T running out of natural gas. Retrieved October 16, 2014, from http://www.guardian.co.tt/

news/2014-10-12/tt-running-out-natural-gas

• Wilson, A. (2014, September 4). Guardian Newspapers. Retrieved October 16, 2014, from http://www.guardian.co.tt/business/2014

-09-03/tt-losing-energy

• World Energy Council. (2010). World Energy Resources Survey 2010. London: World Energy Council.

• World Energy Council. (2013). World Energy Resources 2013 Survey. London: World Energy Council.

• World Energy Council. (2019). Sustainability Index. Retrieved July 14, 2014, from http://www.worldenergy.org/data/sustainability-

index/


ARTICLE REFERENCES

ELECTRICAL—Hand-Held NPK Sensor

• "Changes in Hyperspectral Reflectance Signatures of Lettuce Leaves in Response to Macronutrient Deficiencies." Advances in Space

Research. March 04, 2011. https://www.sciencedirect.com/science/article/pii/S0273117711001499.

• Detecting and Monitoring Plant Nutrient Stress Using Remote Sensing Approaches: A Review. https://scialert.net/fulltext/?

doi=ajps.2017.1.8.

• "ESTIMATING NITRATE, PHOSPHATE, - Plant Physiology." http://www.bing.com/cr?

IG=7E5444361F6B4E6D8C8D6E52B5CA3D3F&CID=176E3E933CFC6808142635543D5369C4&rd=1&h=tYhSoftj8YXzBsxScaY9K

1RRGb3wV00kDaoJ0JpJSMc&v=1&r=http://www.plantphysiol.org/content/plantphysiol/7/2/315.full.pdf&p=DevEx.LB.1,5068.1.

• "Plant Growth Architecture and Production Dynamics." UVED - Plant Growth Modelling - GreenLab Model - Production/Expansion

- Function Equations - Full Model Equation Set. http://greenlab.cirad.fr/GLUVED/html/P2_GLab/Prod/GLprod_equa_013.html.

• "Relay vs. Transistor?" Electrical Engineering Stack Exchange. https://electronics.stackexchange.com/questions/10092/relay-vs-

transistor.

• Stabroek News. (2014, September 15). Proman set to acquire CLICO Methanol Holdings. Retrieved November 21, 2014, from

http://www.stabroeknews.com/2014/news/regional/09/15/proman-set-acquire-clicos-methanol-holdings/.

• Terashima, Ichiro, Fujita, Takashi, Inoue, Takeshi, Chow, Wah Soon, Oguchi, and Riichi. "Green Light Drives Leaf Photosynthesis

More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves Are Green | Plant and Cell

Physiology | Oxford Academic." OUP Academic. February 25, 2009. https://academic.oup.com/pcp/article/50/4/684/1908367.

• "The Role of Chlorophyll Fluorescence in The Detection of ..." http://www.bing.com/cr?

IG=8F2300217992474B88216997CDC7C9A8&CID=389BDB53A65A6FB21FB6D094A7F56E4B&rd=1&h=ZAF_FDe1hPIeM_nncCTHFLydnJIh4odtU6kA2TyzrH0&v=1&r=http://www.tandfonline.com/doi/abs/10.1080/15476510.1988.10401466?

journalCode=batc19&p=DevEx.LB.1,5508.1.

• "Use of Spectral Reflectance Values for Determining ..." http://www.bing.com/cr?IG=A24FFDE6B259493E9913631B946BB013&CID=18DDD895A4A06B613D3AD352A50F6A60&rd=1&h=gD0jACNXvW4I-

8aKaRkQQQKsk-82tVjyhuFQCHoIb7I&v=1&r=http://jast.modares.ac.ir/index.php/ejb/article/viewfile/56560/journal/

article_10232.html&p=DevEx.LB.1,5488.1.

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