the role of computational thinking in the 21 century - appropriate
TRANSCRIPT
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THE ROLE OF COMPUTATIONAL THINKING IN THE 21ST
CENTURY
1 Jackson J. and
2Moore L.
1Jackson State University, Department of Computer Science
PO Box 18889, Jackson, MS 39217, USA 2Jackson State University, Division of Research and Federal Relations
PO Box 17057, Jackson, MS 39217, USA
Email: [email protected]
Keywords: Computer Science Education, Computational Thinking
Abstract
Computational Thinking is a problem solving methodology that uses the concepts of
Computer Science such as abstraction, algorithms, problem decomposition, simulation and
parallelism to solve problems not only in Computer Science but Biology, Chemistry,
Engineering, Sociology, and other disciplines. This methodology focuses on the development
of an individual’s ability to: (1) solve open-ended problems; (2) organize and analyze data;
(3) identify possible solutions to a problem; (4) use abstraction to create models; and (5)
collaborate in teams. Supporters of Computational Thinking believe that it will better
prepare students for college and the workforce. Computational Thinking also develops
critical thinking skills that are necessary for reading and writing. To be a productive citizen
in today’s world, the skill set that Computational Thinking develops is needed.
The overall goal of the Computational thinking initiative at Jackson State University is to
provide a new level of technical competence to students from a variety of disciplines in order
to have a better educated computing workforce and overall citizenry by discovering and
imparting the necessary Computational Thinking skills. This paper will discuss in detail the
accomplishments of the Computational Thinking program as well as shed insight on the role
of Computational Thinking in the 21st century.
INTRODUCTION
In the Fall semester of 2010, the Department of Computer Science at Jackson State
University embarked upon a mission to change the image of Computer Science through
Computational Thinking. The goal of the Computational Thinking initiative was to expand
the definition of Computer Science and to introduce non-computing majors to concepts of
computing that could be used to solve problems.
Computational Thinking was first introduced by Jeannette Wing [21]. In this groundbreaking
paper, Wing suggests that Computational Thinking should become like reading and writing, a
necessary skill for everyone not just Computer Scientists. Computational Thinking is a
problem solving methodology that uses the concepts of Computer Science to solve problems.
A variety of approaches to teaching introductory Computer Science (CS) courses have been
introduced [5,6]. These approaches, however, focus on programming. The goal of the
breadth-first approach was to provide students with an overview of the discipline first. Even
1 Author for correspondence
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though this approach provides that overview, it is often too focused on programming and an
ideal model has not been identified yet [5].
Computational thinking takes the focus off of programming and places it on the development
of the skills necessary to program. Key concepts of Computer Science highlighted within
Computational Thinking include: data collection, data analysis, data representation, problem
decomposition, abstraction, algorithms & procedures, automation, simulation, parallelization.
An advantage of this methodology is that it is discipline independent. Supporters show that
the concepts of Computational Thinking can be used to develop an individuals' ability to: (1)
solve open-ended problems; (2) organize and analyze data; (3) identify possible solutions to a
problem; (4) use abstraction to create models; and (5) collaborate in teams [4].
Computational Thinking provides foundational knowledge in problem solving and design.
Supporters of Computational Thinking believe that it will better prepare students for college
and the workforce. It is also a link to innovation. Computing and innovations linked to
technologies are some of the fastest growing areas worldwide. According to Jeanette Wing
[21], Computational Thinking should be added to an individual’s skill set. Wing challenges
the Computer Science (CS) field to (1) change the first course CS freshman take from
“Introduction to Programming” to “Ways to Think Like a Computer Scientist”, (2) provide
this course to not only CS majors but to all students, and (3) expose the K-12 community to
Computational Thinking methods.
The National Science Foundation’s (NSF) Computer and Information Science and
Engineering (CISE) Directorate funded two workshops that examined the role and scope of
Computational Thinking. The first workshop [2] examined the definition of Computational
Thinking, applications of Computational Thinking, and how Computational Thinking can be
applied to more than just Computer Science. This workshop resulted in two open questions:
(1) does Computational Thinking vary by discipline and (2) what role does technology play
in Computational Thinking. The focus of the second workshop [3] was to design ways to
bring Computational Thinking into mainstream K-12 education. Participants in the workshop
discussed Computational Thinking challenges, opportunities, practices and strategies for K-
12 integration.
The interest in this area is apparent. A number of researchers at the University of California at
Los Angeles (UCLA) are exploring strategies for promoting computing and Computational
Thinking including the Into the Loop and Participatory Sensing projects [13,9]. Peckham and
Taylor [16] encouraged attendees to consider Computational Thinking as the 4th R (along
with Reading, Writing, and Arithmetic as fundamental skills) during a presentation at the
2008 Expedition Workshop. Other individuals and organizations involved in Computational
Thinking include: Peter Denning [8], Carnegie Mellon University [1], and the Computing
Research Association – Education [7]. Recent CPATH projects included Computational
Thinking as a key component [11, 14, 19, 20]. The University of Arizona and Kentucky
University are examining how Computational Thinking can be incorporated into STEM
disciplines. Purdue University and Marietta College are examining how Computational
Thinking can be infused into the K-12 community.
JSU COMPUTATIONAL THINKING PROJECT
The Department of Computer Science at Jackson State began a Computational Thinking
Initiative in 2010 in an effort of increasing student enrollment and interest in Computing.
This initiative is funded by NSF Award #1062118. The Advancing Computational Thinkers
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and Computing Innovators in a Cyber-Enabled Community project aims to serve as a catalyst
for increasing interest in and understanding of computing. This effort focuses on the
establishment of a new course on Computational Thinking and on the enhancement of the
freshman and sophomore level experience by integrating components of Computational
Thinking throughout the first two years of study.
The overall goal of the this initiative is to provide a new level of technical competence to
computing students as well as students from a variety of disciplines in order to have a better
educated computing workforce and overall citizenry by discovering and imparting the
necessary Computational Thinking skills. The specific objectives are to: 1) Better prepare
students for core Computer Science courses by providing students with enhanced problem
solving skills gained through Computational Thinking; 2) Increase student interest in
pursuing a Computer Science degree by exposing them to cutting edge research in their
Freshman year; 3) Increase the retention rate of Computer Science majors by providing a 1st
and 2nd year experience which focuses on enhanced problem solving skills and exposure to
opportunities for innovative thinking; and 4) Prepare students University-wide with
Computational Thinking knowledge, skills, and dispositions. The implementation plan
includes: 1) developing a Computational Thinking course; 2) developing a set of units that
can be integrated into Computer Science core classes; and 3) creating a framework for
Computational Thinking for K-16 across various disciplines.
The Computational Thinking course is taught by six professors from the Departments of
Computer Science and Sociology and consists of the following units: Robotics; High
Performance Computing: Modeling, Simulation, and Visualization; Data, Data Analysis, and
Visual Analytics; Virtual Organizations for Distributed Communities; and Mobile Computing
Environments for Learning. Given the lack of females choosing Computer Science as a
major, one of the approaches of this initiative was to show the diversity within computing. Of
the professors, (1) five were female and one was male and (2) five were African-American, 1
was Asian. Through the active involvement of a Professor from Sociology, students saw that
Computational Thinking was not only for the STEM disciplines. The selected units represent
active research areas of the professors.
Each unit is approximately three weeks in length and culminates in a group project (with
demo and presentation) and an individual quiz. The course is designed as team and laboratory
based with minimal traditional lecturing. Technologies chosen for project implementation
require no formal programming. They include: Lego MindStorm Robots [15], Phun [17],
ManyEyes [12], SecondLife [18] and Google App Inventor [10]. Phun, ManyEyes, SecondLife
and Google App Inventor are freely accessible tools.
Students work in interdisciplinary teams to complete the project and formally present their
results. Through the unit experience, students gain practical design and implementation
experience in the following advanced computing areas: modeling, simulation, visualization,
visual analytics, data analysis, virtual organizations, distributed computing, mobile
computing, access computing, robotics, and social and ethical issues of computing. Students
obtain an understanding of fundamental computing concepts, such as: variables, control
structures, functions, problem solving strategies and algorithms, basic hardware architecture,
operating systems, data types, sound, audio, video, graphics and user interface events.
The course introduces students to the principles of Computational Thinking, focusing on the
fundamental concepts of computing as they apply to various disciplines. The course pre-
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requisite is general computer knowledge and the ability to use Microsoft Office products. On
average, two professors are responsible for each unit. No textbook was required for the
course. The instructors utilized on-line resources and course delivery was via PowerPoint
lectures.
Upon the completion of this course, students are expected to: (1) Understand the
fundamental concepts of computing; (2) Identify the benefits and current limitations of
modeling, simulation, visualization data analysis, visual analytics, virtual organizations,
social interaction, mobile computing, and robotics in various contexts; (3) Articulate
advanced computing concepts to a variety of audiences; (4) Apply concepts of Computational
Thinking to various disciplines; (5) Understand the difference between interactions in the real
world versus the virtual world; and (6) Construct basic physical and virtual models using
various technologies.
During each unit, students work on a design project. Each project is specific to each unit and
differs from one unit to the next. For example, during the robotics unit, the students build a
robot and then program it to travel through a maze; during the mobile applications
development unit, the students learn the basics to creating an app and then are given a project
to create an app that can be used for the disabled or as an educational tool.
The Computational Thinking course is available to all students. As part of the University’s
general education requirement, students must take a course in computer literacy. Most
students currently enroll in CSC 115, Digital Computer Principles. Digital Computer
Principles gives students an introduction to word processing, spreadsheet, database, graphics,
computing, data processing, the organization of a computer, input and output devices, number
systems, and internal data representation. In this current age of technological advancement,
many students come to college already with a knowledge of computing and its various
applications. The Computational Thinking course can then be used as a substitute for the
University's computing requirement giving students a deeper exposure to the power of
computing.
RESULTS AND DISCUSSION
The Computational Thinking course has been offered for three semesters: Spring 2011, Fall
2011 and Spring 2012. This course is open to all majors. Sixty-two students from the
following areas have enrolled in the course from the following majors: Art, Biology, Business
Administration, Chemistry, Criminal Justice, Childcare Education, Computer Science,
Computer Engineering, Journalism, Mass Communications, Mathematics, Music
Performance, Physics, Political Science, and Sociology. Student evaluation is based on
performance of five projects (75%) and five quizzes (25%). Overall, students have been very
successful. The pass rate of the course is currently 90%. Those who have not been successful
were those who did not fully engage in the course.
Students have produced very innovative solutions. Most notable are: (1) a pill monitor app
that an elderly individual can use to keep track of medications; (2) an app that teaches young
children their colors; (3) a simulation of a flood; (4) a simulation of wind energy; (5) a
simulation of a space shuttle launch; and (6) a dance competition between avatars in
SecondLife.
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Student achievement on the learning outcomes is assessed by a quiz and a self-assessment of
achievement of student learning outcomes. Students are asked to rank their knowledge of
each learning outcome prior to the course and after the course. Additionally, surveys specific
to the units are administered. Students also assess the course through the university’s Student
Instructional Rating System mechanism.
This project provides students with an overview of current technologies and demonstrates
how these technologies can be used to solve or create solutions to societal problems. During
project evaluation, the Computer Scientists all saw the need to: incorporate team-building
exercises, select a dedicated lab space, maintain student interest (some decrease in interest
after 3rd unit), add more structure to units; however, according to the Sociologist's view the
whole educational process needs to change to include more interaction with the students. Our
charge is to engage our community of students more through human and social interaction.
Open questions include: Are students learning? Or is it simply memorization to complete the
assignment or to pass the test? Can students apply what they have learned to solve other
problems?
Each of the units demonstrates the impact of computing on society. In robotics, students learn
how to build a robot and how to program it to perform certain tasks. They also see how
robotics can be used to make a societal difference. The applications that are demonstrated in
the visual analytics unit show the students how computing applications can be used to solve
problems in homeland security. In Virtual Organizations, students see how technologies
allow for on-line communication. The Mobile Application development unit demonstrates
that apps can be used to provide services to different classes of individuals including the
disabled and children. In modeling and simulation, students see how virtual models can be
created to demonstrate natural phenomenon.
CONCLUSIONS
During the course of this project, sixty-two students from multiple disciplines participated in
the Computational Thinking course. Students were introduced to emerging technologies that
demonstrated the impact that computing has on society. Supporters believe that introducing
students to Computational thinking allows them to develop skills necessary for success in
educational endeavors and the workforce.
Phase II of this initiative will focus on assessment and course redesign. Currently, student
achievement on the learning outcomes is assessed by a quiz and a self-assessment of
achievement of student learning outcomes. There is a need for a more formal assessment. As
the project moves forward, one of the focus areas will be to determine how to properly assess
which Computational Thinking competencies the students have learned and at what level.
The course will also be redesigned to include a focus on critical thinking and analytical
reasoning. Critical thinking and analytical reasoning exercises will be embedded into the
course content. Students will learn (1) how to interpret, analyze and evaluate information; and
(2) how to draw conclusions and propose appropriate courses of actions. The revised course
will be scenario based. Technologies will be introduced first and then the students will be
presented with scenarios where they will have to use the technologies to create solutions to
the problems.
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ACKNOWLEDGEMENTS
This project was funded by the State Farm Foundation and the National Science Foundation
(Award##1062118).
REFERENCES
[1] Center for Computational Thinking, Carnegie Mellon,
http://www.cs.cmu.edu/~CompThink/,
last accessed: July 28, 2012.
[2] Committee for the Workshop on Computational Thinking: National Research Council,
Report of a Workshop on The Scope and Nature of Computational Thinking,
http://www.nap.edu/catalog/12840.html, last accessed: July 26, 2012.
[3] Committee for the Workshop on Computational Thinking: National Research Council,
Report of a Workshop on Pedagogical Aspects of Computational Thinking,
http://www.nap.edu/catalog.php?record_id=13170#description, last accessed: July 28,
2012.
[4] Computational Thinking Teacher Resources, http://www.iste.org/learn/computational-
thinking/computational-thinking_toolkit.aspx, last accessed: July 28, 2012.
[5] Computer Science Curriculum 2001:
http://www.acm.org/education/education/curric_vols/cc2001.pdf?searchterm=Computing
+Curriculum+2001, last accessed: July 26, 2012.
[6] Computer Science Curriculum 2008: An interim revision of CS 2001,
http://www.acm.org//education/curricula/ComputerScience2008.pdf, last accessed: July
26, 2012.
[7] CRA-E, Creating Environments for Computational Researcher Education,
http://cra.org/uploads/documents/resources/rissues/CRA-E-Researcher-Education.pdflast
accessed: July 28, 2012.
[8] Denning, P., Great Principles of Computing, http://cs.gmu.edy/cne/pjd/GP, last accessed:
August 18, 2010.
[9] Goldman, J., Shilton, K., Burke, J., Estrin, D., Hansen, M., Ramanathan, N., Reddy, S.,
Samanta, V., Srivastava, M. and West, R., Participatory Sensing, A citizen-powered
approach to illuminating the patterns that shape our world,
http://wilsoncenter.org/topics/docs/participatory_sensing.pdf, last accessed: July 28,
2012.
[10] Google App Inventor, MIT Center for Mobile Learning, http://appinventoredu.mit.edu.
[11] Hambrusch, S., Hoffman, C., Lehman, J., Yadav, A. and Rud, A., CPATH-2: Computer
Science Pathways for Educators, NSF Award# 0938999.
[12] IBM Many Eyes, http://www-958.ibm.com/software/data/cognos/manyeyes/
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[13] Into the Loop and Computer Science Equity Alliance,
http://idea.gseis.ucla.edu/projects/into-the-loop, last accessed: July 28, 2012.
[14] Kirby, K., CPATH-1: Informatics at Multiple Scales, NSF Award#0939103.
[15] Lego MindStorm Robots, http://mindstorms.lego.com/
[16] Peckham, J. and Taylor, H., Computational Thinking The Fourth ‘R’,
http://csta.acm.org/Communications/sub/CSTAVoice_Files/csta_voice_05_2011.pdf,
last accessed: July 28, 2012.
[17] Phun, http://www.algodoo.com/wiki/Phun
[18] SecondLife, http://www.secondlife.com
[19] Snodgrass, R., CPATH-2: Collaborative Research: A Field Guide to the Science of
Computation, NSF Award# 0938948.
[20] Van Camp, R., Miller, M., Wang, J. and Lewandowski, S., CPATH-1: CPATH at
Marietta College, NSF Award#0939106.
[21] Wing, J.M. (2006). Computational Thinking. CACM, vol. 49, no.3, pp. 33-35.
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MINING POLICIES IN GUYANA CHANGING THE HINTERLAND
Dalgety W. T.
Director, Guyana Geology and Mines Commission, GGMC, Georgetown, Guyana
86 Robb Street, Lacytown, Georgetown, Guyana Tel: +592 226 5159
Email: [email protected]
Key Words: Policy, declared production, feudalism, hinterland, sanitation
Abstract
On July 15th 1991, in order to allow the Guyanese population to do gold (and diamond)
mining legitimately, the Guyana government introduced new regulations for Small and
Medium Scale mines into the Guyana Mining Act of 1989. Since then, thousands of Guyanese
have been applying for mining properties. Since then, production targets in gold have been
set by the authority charged with the responsibility of managing the minerals and mining
sector of the economy – the Guyana Geology and Mines Commission, GGMC. Guyanese
miners have always exceeded annual gold production targets. Much of this is due to
Guyanese property owners reaching out to foreign skilled labour particularly from Brazil
their neighbour to the south. Production of gold (and diamonds) is vital to Guyana’s foreign
revenue. The present gold rush, 2012, has brought security concerns and changing
immigration and work permit policies into focus. The demand for sustained, skilled labour
has highlighted the need for a change in sanitation regulations at camp sites. Increased
production shows the need for better educated men and women who would consider careers
in mining. Men and women who accept the rigors of research to inform replacing the
traditional mercury processing that has been the forte of artisan pork-knockers since the
middle of the 19th century. This year a Women Miners Association and Brazil Miners
Association were formed. Both sought associate status in the Guyana Gold and Diamond
Miners Association, GGDMA, which was formed in 1984. This paper by a member of the
Board of Directors of the GGMC discusses the 2012 gold rush in Guyana. It is about the
battle to change the feudal pork-knocking habitat and mentality in Guyana’s hinterland and
so change the lifestyle of Guyanese.
Introduction:
On July 15, 1991 new mining regulations plus permission for geological and geophysical
surveys were signed into law in Guyana. On July 15, 2012 the Trans-Atlantic Slave Trade
Commemoration Committee sponsored a lecture entitled ‘Mining Policies 1991 to 2012’
delivered at the Museum of African Heritage to observe 21 years of Medium Scale (m/s)
mining by Mr. William Woolford former Commissioner, Guyana Geology and Mines
Commission GGMC. Before 1991 only small scale (s/s) or large scale (l/s) mining was legal
in Guyana. Medium scale mining was intended to usher in a new middle class and made
economic improvements real for the pork-knockers (African gold miners working
individually or cooperatively) who for centuries wandered the hinterland mining gold. By
middle class this paper means an ‘investment class’ of citizens in partnership with other
Guyanese or foreigners and an ‘equipment class’ of citizens owning and doing business with
industrial equipment.
The Regulations of 1991 made the Mining Act of 1989 operational. Mining Act of 1989
introduced medium scale (m/s) mining as a totally new classification in property tenure.
i) Small scale (s/s) - property of 1500x800ft [27 acres] for land claims and for river
claims one mile [0.6km] of navigable river.
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ii) Medium scale (m/s) - properties and mining permits of 150 – 1200 acres
iii) Large scale (l/s) - prospecting licence of 500 – 12,800 acres
iv) Permission for geological and geophysical surveys (reconnaissance). Surveys are
to be done with the objective of applying for prospecting licences after the aerial
and/or land reconnaissance results are obtained.
From 1992 thousands of Guyanese have worked within the new system of property
ownership.
Table 1. Tenure Arrangements (Small and Medium Scale Gold Mining) 2009 – 2012 projected Tenure 2009 2010 2011 2012 (projected) Claims (s/s) 13,476 14,335 15,032 16,500 Prospecting Licences (s/s) 261 136 191 189 Prospecting Permits (M/S) 7,273 4,879 5,141 7,053 Prospecting Permits (s/s) 932 1,147 991 1,000 Mining Permits (M/S) 646 742 1,161 1,738 Mining Licences (M/S) 11 7 12 29 Reconnaissance(l/s) 21 3 8 15
Source - GGMC
Guyanese can begin as self-employed legal miners for only G$1000.00 by buying a
prospecting permit small scale s/s from the GGMC and legally search for gold for 60 days.
If, during the 60 days gold is found using battel and jig or a metal detector he can apply for a
claim according to William Woolford [1]. The gold rush projects 16,500 claims in 2012
The gold rush is also recognized by quarterly gold production by mining districts in 2011 and
2012 (Table 2). Between January and June 2012 GGMC budgeted for a declared production
of 167,000 ounces of gold and the actual declared production was 184,726 ounces.
Table 2: Quarterly Gold Production (ounces) by Mining Districts 2011 to June 2012
Mining
District
1st QTR 2
nd QTR 3
rd QTR 4
th QTR Total
2011
1st QTR
2012
2nd
QTR
2012
Berbice 0 0 0 0 0 - -
Potaro 14,406 18,017 18,037 18,425 68,885 19,599 21,079
Mazaruni 21,653 27,392 30,010 30,561 110,616 22,328 23,180
Cuyuni 23,893 22,743 27,333 25,192 99,161 18,954 20,003
N / West 12,796 14,769 16,040 15,704 59,309 15,769 16,396
Rupununi 5,161 4,327 7,165 8,459 25,112 12,123 15,295
Total 77,909 87,248 99,585 98,341 363,083 88,773 95,953
Source: GGMC
Property and production figures have increased annually since 1992 due to mining policies.
Some policies were influenced by the Guyana Gold and Diamond Miners Association
GGDMA. First, gold producers can open foreign currency accounts at local Banks. Second,
easy availability of foreign currency has aligned miners’ attitude to truthful declaration of
their production. Third, gold producers now enjoy the following: 1)duty free concessions on
vehicles and equipment, ii) reduction in rentals subject to low gold prices, iii) auction/lottery
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for mining blocks, iv) representation on critical enterprises such as GGMC, Guyana Gold
Board, Ministry of Finance, Environmental Protection Agency and Guyana Lands and
Surveys Commission, and v) miners Tax Liability at 2% on gross declaration [2].
Record declared gold production is also linked to the presence of Brazilian miners in the gold
fields. First, according to Edward Shields, executive secretary of the GGDMA 1984 to 2011,
“Brazilians have helped to reenergize the mining industry”[3]. Thousands are in the gold
fields legally but many are also there illegally. In April 2012, there was a policing dragnet of
the hinterland as part of Operation El Dorado to stop illegal mining. Some Brazilians were
deported and others detained. The response was an outcry from many stake holders including
the GGDMA demanding the speedy issuance of work permits to all workers so that
production is not stopped. This incident precipitated the formation of The Brazil Mining and
General Association, BMGA, on May 02, 2012. Second, Brazilians have introduced new
technology into the industry like the cutter-head dredge. Third, because Guyanese law
prohibits foreign ownership of small and medium scale properties, Brazil investors have to
joint venture with Guyanese property owners. Brazilians are involved in all aspects of the
gold industry.
Despite changes and gains from the new regulations, the workers in mining communities live
under ‘feudalism’. By feudalism this paper means that vassals work in the mines in muddy
and insanitary conditions producing wealth for owners who live comfortably in non-mining
areas.
This paper discusses the 2011 to 2012 gold rush. It is about the battle by a Director of the
GGMC to change the feudal habitat and mentality in Guyana and so change the lifestyle of
Guyana. The battle has to do with i) money and policy, ii) technology and iii) communities,
feudalism and sanitation in the hinterland.
Money and Policy
Table 3: GGMC income from 2008. Source: GGMC
Year 2008 2009 2010 2011 2012proposed
G$ billion 3.6 4.3 4.9
Government and GGMC have been enriched from gold production over many years, Table 3.
In 2011, GGMC earned G$5.2 billion from rents, royalty and other fees. Gold sales
contributed over 50% of Guyana’s foreign exchange earnings - more than the contribution of
the agriculture sector. The gold industry contributed significant income tax revenues to the
Inland Revenue Authority through direct and indirect employment. Local equipment
manufacturers and foreign suppliers of excavators and bulldozers earn billions from sales to
gold miners. The marketing chain (Figure 1) outlines the gold miners’ story from mining to
sale of his gold [4]. Government policy is to remove hindrances to income streams and to
provide special incentives to gold miners.
Small and Medium scale miners:
1. Do not have to give topological description of their property
2. Have no restriction on the number of pits on a property
3. Provide no proof of financial and technical capability
4. Lodge no performance bond
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5. Submit no progress reports to GGMC
6. Pay gold royalties at 5% of gold output to GGMC
7. Pay taxation at 2% of gross revenue for individuals to the Inland Revenue Authority
8. Have discretionary exemption from customs duty and VAT
9. Receive advice on environmental matters
10. Must sell gold to the Guyana Gold Board, registered dealers or their agents
Figure1: Gold Marketing Chain: small and medium scale gold mining sector.
Source: GGMC
Additional policy is now to provide geological data and technical assistance to miners, fund
and construct hinterland infrastructure so that gold can get to the market quickly. Officers
advise on mining, processing, utilization, marketing and where possible they must help with
exploration. The overall policy objective is to (i) increase foreign exchange earnings, and (ii)
increase revenue for GGMC.
Technology:
The major categories of commercially viable recovery processes include the following: 1)
Amalgamation 2) Gravity concentration 3) Flotation 4) Pyrometallurgy 5) Hydrometallurgy
6) Refractory ore processing [5] (Figure 2). The selected technology however must be
appropriate for the particular mining scenario.
Situation Analysis 2006 stated “operators in Guyana work three types of gold deposits (i)
river deposited placers of the present and old river systems (riverbeds, floodplains and
terraces) (ii) Eluvial saprolite-hosted deposits and (iii) gold-bearing quartz veins and
stringers. Eluvial deposits produce mainly fine-grained gold and such deposits present a
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greater requirement for preliminary geological work prior to mining”. Whether it is coarse-
grain or fine-grain Guyanese gold miners use sluice box and amalgamation with mercury
from which they recovery roughly 40% of gold. This process depends on water and labour
principally.
Figure 2. Basic flowchart for gold recovery:
Source: Minerals Metals and Materials Technology Centre, National University of Singapore
Most ‘investment class’ miners have little science education and resist new technology – the
application of science. Woolford said that the sluice box can give a recovery rate of 90%
since gold has a specific gravity of 19.2 compared with the rest of the slurry with an average
specific gravity of 2.5. An operator with this knowledge and some understanding of
centrifugal force can increase recovery above 40%. But few operators have played with a
centrifuge at secondary school to understand centrifugal force or gravity. Local industrial
processes are not in current text books.
Randy Clarkson in ‘An Analysis of sluice box riffle performance’ wrote that “properly
functioning riffles are actually centrifugal concentrators with settling velocity playing a minor
role in gold recovery. Gold particles tend to segregate to the bottom of the slurry flow where
they form a streamline that is diverted by a low pressure zone into a riffle. Under ideal
conditions the rear of the downstream riffle overturns the streamline and it continues flowing
in a circular path to form a vortex. At the bottom of the vortex, centrifugal and gravitational
forces combine to drive the gold particles into the matting. Gold particles which are caught
in the matting are very resistant scouring losses” [6]. (Figure 3)
GGMC has done a number of things to improve the technology available to miners. GGMC
is working at transferring sluice box technology to miners. GGMC has a diversification
policy. GGMC has purchased a Falcon concentrator, two Knelson concentrators, a shaking
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Figure 3. Source: Randy Clarkson
table to demonstrate gravity separation and the units of cyanide with carbon-in-pulp pilot
plant to educate large scale operators. GGMC is fabricating the units of a flotation plant to
demonstrate flotation technology. The cyanide technology is the least likely to be adapted by
miners because it is impracticable - requiring a staff of scientists and electricity supply.
Recovery technology however is still basically at Category 1 of commercial processing –
amalgamation. Guyanese need to move to Category 2 – gravity separation
Communities, feudalism and sanitation in Mining Districts
Director Dalgety has visited communities and camps in Potaro District (Mahdia), Mazaruni
District (Bartica and Tamakay), Cuyuni District (Aranka) and North West District (Port
Kaituma). All mining districts have unincorporated communities gazetted as townships,
villages, settlements, landings, localities and rivers indicating sizes since the era of British
overlords [7].
After enslavement, British overlords related to Africans in hinterland communities by
granting to them ‘privileges’ to mine gold for 12-month periods. Legally, Africans could not
live, only work in the hinterland. An African in possession of a privilege, called a ‘tributor’,
kept a per cent of his winnings of gold as payment for work done – payment in kind. He was
harassed or jailed by the police if found with gold but without a privilege. In this paper, the
system of overlords and privilege-policing of workers is considered feudalism. The 1992 -
2012 feudalism in Guyana is less tolerable than that of the British. All categories of salaried
workers such as cooks, excavator operators, bulldozer operators, greasers and mechanics in
162
the mining districts must possess a Certificate of Registration to receive pay or they are
deemed criminals. Property owners must keep a ‘slave book’ with excessive information of
their workers including death and burial. Workers are regularly buried in dishonorable
graves. Police raids to check if workers have ‘papers’ are frequent. This is tyrany. The need
to remove these conditions is urgent [8].
GGMC has never insisted on basic sanitation in the mining districts. Basic sanitation means
access to latrines and toilets. GGMC as well as property owners are indifferent to
development and maintenance of sanitary facilities. Camp toilets are non-existent. Director
Dalgety brought this to the attention of the Prime Minister of Guyana in 2010. He replied
that he was 100% in agreement that toilets should be installed in camps. Toilets will make
the change from prostitute to significant female easier. Within the system of feudalism this
change is herculean. These are Director Dalgety’s findings:
A) Mahdia, in Potaro mining district, is a ‘settlement’ with approximately 150 land
dredges within a three mile radius. The ‘proto mahdia’ channel and other old river
channels to lower Potaro River have made it the centre of Potaro mining since 1884`.
Millions of dollars in gold is held and hidden by miners of Mahdia before being
transferred to Guyana’s capitol. Six hundred households live with unpaved roads.
Mahdia’s commercial center includes a dry goods store, boutiques, fuel station and
eleven restaurants. Welfare Officer Jacqueline Wilson reported on June 8, 2012 that
“eating houses in Mahdia don’t have a washroom to wash your hands much less a
toilet for patrons”. She also wrote that “Mahdia is still considered a landing since it
has no village council which was never established in this area” [9]. Improved
sanitation in camps was addressed by the Guyana Environmental Capacity
Development GENCAPD in 2010. GENCAPD designed toilets were to be
constructed at Mango Landing the terminals on the Essequibo River that links Mahdia
to Georgetown. At 2012 no toilet has been constructed on either embankment of
Mango Landing nor is there a toilet on the ferry.
B) Bartica is a ‘village district’ and Tamakay a ‘locality’ in Mazaruni mining district –
the district with the highest production of gold. British authorities ‘regulated’ Bartica
for gold in 1887. Bartica was considered the gateway to the hinterland before the
Soesdyke-Linden Highway alternative was built in the 1970s. Its beach-front has an
industrial area where dredges are fabricated. The gold rush is modernizing the
village. Tamakay is in middle Mazaruni River between Kamarang near the source
and Itabali near the mouth. Its feudal character is startling - a locality with Brazilian
women working as prostitutes, cooks, shop-keepers and dredge managers. It has
dilapidated rooming apartments and dilapidated latrines. Open defecation takes place
at back of the locality. The presence / absence of village councils are a yardstick of
what feudalism is.
C) Aranka, in Cuyuni mining district, is a ‘river stop’ 167km from the mouth of the
Cuyuni River where GGMC has a dilapidated station making sex in full view easy. Its
degeneration belies the commerce on the waterway. Cuyuni River starts in
Venezuella. Throughout this commercial waterway there are international traders,
open defecation and a feudal mentality that understands what has to be done to relate
to overlords.
163
D) Port Kaituma, in North West mining district, is a ‘settlement’. This small
commercial-feudal settlement is linked to Georgetown by air and ocean steamer
transport. Property owners send equipment and rations to this settlement for
distribution to camps throughout the district. The district is one stage above slavery
with media reports of policemen and miners having shootouts and murder of rogue
policemen (Demerara Waves, 10 18 2012).
The arithmetic that confirms gold and feudalism in 2011 is startling:
District Production Earned US$ million Earned G$ billion Remarks
Potaro 68,885 110.2 22.0 Discuss: GGMC as
Mazaruni 110,616 177.0 35.4 the engine of
Cuyuni 99,161 158.7 31.7 feudalism
North West 59,309 94.9 19.0
Conclusion and path forward
The mining districts were mapped in 1942 in the era of British overlordship when mining was
considered secondary to agriculture [10]. As revenue from gold mining outstrips that from
agriculture Guyana is a mineral economy. Policy must reflect this. First, remapping must
show mining districts from the Atlantic Ocean to Kanuku Mountains. Policy must change
from one that allows work only to a policy that allows one to live in the hinterland with good
residential conditions. Second, beyond mercury there are other commercially viable recovery
processes. Third, the overlords must move from Georgetown and live in the hinterland.
The future is to shift understanding of Guyana as a mineral rather than an agriculture
economy. GGMC must be reorganized to reflect core divisions: 1) Base Metals 2) Gold and
Precious Metals 3) Precious Minerals and semi-precious Stones 4) Industrial Minerals 5)
Energy minerals & materials, allowing greater focus and development of each grouping.
GGDMA must lead the struggle against feudalism.
REFERENCES [1] Woolford W, Mining Policies 1991 - 2012, Museum of African Heritage lecture July15,
2012
[2] Sparman C, Letter to valued members of the GGDMA October 20, 2011
[3] Lowe S and Vieira R (Ed), Situation Analysis of the small-scale mining sector in Guyana,
World Wildlife Fund, Guianas Regional Program, 1-96, 2006.
[4] Babb D and Abrams W, Dataset required for an analysis of “Real” production of gold,
GGMC Board of Directors Technical Committee Presentation, November 2011, 1-5
[5] Wong wai leong Eugene and Aruns Mujumdar, Gold Extraction and Recovery Processes,
M3TC, National University of Singapore, 5-6, 2009
[6] Clarkson R and Peer D, An Analysis of Sluicebox Riffle Performance, New Era
Engineering Corporation, 4 – 25, 1990
[7] Gazetteer of Guyana, lands and surveys department, Government of Guyana, 2001
[8] Duff-Yehudah and Butters, Offences prevalent in the Mining Industry, GGMC, 2011
[9] Wilson J, Welfare Officer Mahdia, personal E-mail June 9, 2012
[10] Benjamin-Noble R, Legal Adviser GGMC, Exclusion of coastal areas from mining
districts, note to Board of Directors GGMC, October 16, 2012
164
TREADLE OPERATED ENSET (ENSETE VENTRICOSUM) SHEAVES
DECORTICATING MACHINE
Girma Gebrewold
Adama Science and Technology University, School of Engineering and Information
Technology, Department of Mechanical and Vehicle Engineering
P. O. Box 1888, Adama, Ethiopia, E-mail: [email protected], Mobile:
+251911622042
Key words: appropriate technology, treadle sheaves decorticating, food processing
Abstract
Enset (Ensete Ventricosum) is related to and resembles the banana plant (Plate 1, appendix)
and is produced primarily for the large quantity of carbohydrate-rich food found in a false
stem (pseudostem) and an underground bulb (corm). More than 20 percent of Ethiopia’s
population depends upon Enset for human food, fiber, animal forage, construction materials,
and medicines. Enset sheathes is decorticated using a locally made bamboo scraper against a
wooden plank. Women may sit and use one leg to hold the leaf sheaths in place. This
traditional method is inefficient, tiresome, unhygienic, degrading and gender biased. The
paper discusses the analysis and design of a new machine, which improves almost all of the
problems of the traditional method. The machine is foot powered treadle mechanism, which
combined with a quick return mechanism (crank-shaper type) results in a horizontal straight
cutting motion of a decorticating blade to sheave the bundle of Enset sheaves placed on a
table.
Introduction
Enset (Ensete ventricosum) is the main crop of a sustainable indigenous African system that
ensures food security in a country that is food deficient [`1]. Enset is related to and resembles
the banana plant (fig 1.1) and is produced primarily for the large quantity of carbohydrate-
rich food found in a false stem (pseudostem) and an underground bulb (corm). More than 20
percent of Ethiopia’s population (more than 10 million people — the precise number of Enset
users is unknown), concentrated in the highlands of southern Ethiopia depend upon Enset for
human food, fiber, animal forage, construction materials, and medicines.
Enset processing is carried out by women using traditional tools (fig 1.2), and the process is
laborious, tiresome, and unhygienic. The processing is done totally by women in most ethnic
groups; however, men occasionally assist women, as among the Gamo.[2]
Fig 1.1. Enset plant
165
At harvest, leaves and older leaf sheaths are first removed from the designated plants. The
internal leaf sheaths (commonly up to two meters in length) are separated from the
pseudostem down to the true stem, which is about a 20 centimeter section between corm and
pseudostem (fig 1.3).
Then the true stem is separated or stumped from the underground corm. The concave side of
the leaf sheath is peeled and cut into pieces of about one meter length and split lengthwise in
order to shorten the leaf sheath to a workable size. Then the leaf sheath is decorticated using a
locally made bamboo scraper while the leaf sheath is held on an incline (at 45 to 80 degrees
from the ground) against a wooden plank (fig. 1.4). In some groups, women may sit on the
ground (often on Enset leaves) and use one leg to hold the leaf sheaths in place, while in other
areas they bind the sheath to the board and stand to decorticate. The working area used for
decortication is covered with Enset leaves. There is variation in tools used (bamboo versus
newly adopted metal scrapers).
Fig 1.2 Enset preparation Fig 1.3 Enset pseudostem
Fig 1.4. Traditional Enset decorticating
166
Attempts to improve this problem of Enset decorticating are rare. Researchers at Ethiopian
Melkassa Agricultural Implements Research center, Temesgen et al [6] improved the
clamping mechanism (fig 1.5 & fig 1.6). This is a significant development over the traditional
method which used the operators foot for clamping.
However, their work doesn’t improve the drive mechanism; and no attempt was made to
improve productivity.
The Design of Treadle Operated Enset Decorticating Machine
In this paper, the design of a treadle powered, foot operated, Enset decorticating machine is
postulated by the inventor to be the solution to the problem. Horizontal straight line scrapping
movement is attained by a quick return mechanism which changes rotary motion of a shaft
affected by treadle motion of foot pedal.
The present invention remedies the shortcomings of the traditional Enset scrapping method.
The new machine,
eases labour
is by far more comfortable (ergonomical) to operate.
has a faster production rate.
improves hygiene of the work (no contact of human hand or feet with food item).
Needs less skill and more attractive for men to involve in the work that was otherwise
an unfairly total woman work.
Results and Discussions
Parts and Operation Description of the Machine
The designed Enset decorticating machine is driven by a foot powered treadle mechanism (1)
which via connecting links (2) rotate a crankshaft (3) which in turn rotates two discs (4) on
either vertical sides of the machine. The discs mounted on a vertical crank shaft rotate due to
the treadle movement. A pin (5) fixed near the periphery of the disc is fitted to a slotted arm
Fig 1.6 Woman using Marc decorticator Fig 1.5 Marc Improved decorticator
167
(6). Motion is thus transmitted from the disc to this arm, which swivels. The arm is pin
jointed to another connecting rod (7) and this latter rod to a guided shaft (8) which is
constrained to move in a horizontal straight motion. The decorticator, which is the diamond
shaped rod (9), is mounted on this guided shaft (8).
Thus this treadle powered quick return mechanism will change the foot movement on the foot
pedal to a horizontal straight movement of a diamond shaped tube fitted to the shaft. The
longer edges of the tube are sharp enough to peel of the sheaves of Enset piled in a holding
container and strapped on the right end to prevent slippage during shearing action. The
sheave containing box is fitted with compression springs at the bottom to enable feed and
maintain contact pressure between the sheaves and cutting edge of the rhomboidal tube.
Clamping of sheaves is done by an eccentric cam mechanism (11).
Feeding action is performed by a fixed table (15) with four springs (14) which push up the
movable bed (16). The bundle of sheaves rest on the latter.
The machine is supported by vertical stand frames (12).
Fig 2.1 the improved Treadle Powered
Enset Decorticating mechanism.
168
Parts’ Name
1. Treadle (foot rest & links)
2. Treadle connecting links
3. crank shaft
4. disks
5. pin
6. quick return mechanism link-1
7. quick return mechanism link-2
8. shaft of decorticator
9. decorticator blade
10. piles of sheaves
11. eccentric cam clamp
12. machine stand (frames)
13. decorticator shaft guides
14. compression springs
15. Fixed table
16. Movable sheaves table
Fig 2.2 the improved Treadle
Powered Enset Decorticating mechanism.(patent pending)
169
Conclusions
Enset is not only a staple food for more than 10 million Ethiopians, it also has medicinal as
well as industrial utility. The fact that the existing way of Enset processing is too traditional
and cumbersome has limited its great potential for food security for the country. Drawbacks
of traditional Enset decortications were identified and an alternative machine is proposed.
The new machine
eases labour
is by far more comfortable (ergonomical) to operate.
has a faster production rate.
improves hygiene of the work (no contact of human hand or feet with food item).
needs less skill and
more attractive for men to involve in the work that was otherwise an unfairly total
woman work.
The machine also has considerable industrial applicability. This is evident from the fact that
more than ten million people in Ethiopia use Enset as the primary source of their daily food
item. The traditional way of processing has many deficiencies as described above, hence this
machine is expected to be a better choice by the population which grows and consumes
Enset. The machine is designed guided by the principles of appropriate technology. It also
attempts to represent an innovative approach to empowering people particularly women
Planned Future Work
The following are planned future works.
Detail Analysis and Design
- Detail analytical work of the mechanisms: treadle mechanism, quick return mechanism.
- Kinematic, kinetic, force and stress analysis.
- Design of each part based on the analyses above.
- Part and Assembly drawings using CAD software CATIA or Solid Works.
Prototype Manufacturing
A prototype machine will be manufactured and tested on the sites where the farmers grow
Enset and process. Based on the results of the field test, the necessary modifications will be
made.
Plan for Mass production
Design and manufacturing of the process plans, jigs, fixtures, etc shall be made for mass
production of the machine.
Business Plan
A Business Plan shall be prepared which shows market opportunity, customer and
competition analysis; marketing, financial and management plans. This plan together with the
technical document shall be submitted to the concerned governmental, NGO bodies or others
for financing.
Acknowledgements
The author would like to acknowledge the Korean Intellectual Property Office
(KIPO), the Ethiopian Intellectual Property Office (EIPO), and World Intellectual Property
Office (WIPO) for their encouraging this work of research by Gold Medal award Best
Inventor 2011 (Ethiopia).The help of Wolkite Woreda, Gurage zone (South Ethiopia region),
are also appreciated.
170
References
a. General Literature
[1] Steven A. Brandt et al., Enset-Based Agricultural Systems in Ethiopia. “Tree Against
Hunger” (on-line), available: http://www.aaas.org/international/africa/Enset/ March 2011.
[2] J. P. Modak," Manufacture of Lime-Flyash-Sand Bricks using Manually Driven Brick
Making Machine". Project Report: - Project sponsored by MHADA, Bombay-1982.
[3] J. P. Modak. “Human Powered Flywheel Concept Design, dynamics and Applications
Human Power Vol. 13, pp 3-8, 1998, Journal of International Human Powered Vehicle
Association, U.S.A.
[4] Oskar Wallrapp Fakultät, Lecture Notes Mechanism Design and Analysis, Munich
University of Applied Sciences, Faculty of Precision, Micro and Physical Engineering,
Version SS 2010, January 3, 2010.
[5] Wen-Hsiang Hsieh, et al. “A Study on Novel Quick Return Mechanism.” No. 08-CSME-
13, E.I.C. Accession 3051, Received April 2008, Accepted September 2009.
[6] Ferdu, et al, “An IPM guide for Enset root mealybug Cataenococcus Ensete) in Enset
production”. © Bioversity International, 2009.
b. Patent Literature
[7] Dehondt; Guy. “Method and machine for packing fibrous plants into balls especially
common flax, hemp plant and sisal.” U.S. Patent 7520214, April 21, 2009.
[8] Leduc, et al. “Apparatus for decorticating plant material.” U.S. Patent 5 906 030, May
25, 1999.
[9] Chen, et al... “Decorticating method for separating bast from core of forage chopped
kenaf or the like.” U.S. Patent 5 507 074, April 16, 1996.
[10] Chen, et al... “Decorticating machine with variable speed feed and beater rollers”
U.S. Patent 5 465 464, November 14, 1995.
[11] Gardella; Adriano A... “Mowing machine for harvesting long stem textile fiber
plants.” U.S. Patent 4 151 700, May 1, 1979.
[12] Farley, et al... “Loom harness mechanism.” United States Patent 4170250, 09
October, 1979.
[13] Gorospe, et al... “Quick-return electro-mechanical actuator.” United States Patent
6677844, 13 January 2004.
[14] Cushman, et al... “Foot-operated faucet control.” United States Patent 5263684,
January, 1984.
[15] Caubet; Jacques-Jean. “Method for decorticating seeds.” United States Patent
4335151, June 15, 1982.
171
IMPROVING AND SUSTAINING RURAL LIVELIHOODS THROUGH
RECONFIGURABLE MARULA NUT DECORTICATIONS MACHINE
DEVELOPMENT
N Tayisepi2,
and S Mhlanga2
1,2
Department of Industrial and Manufacturing Engineering, National University of Science
and Technology, P. O. Box AC 939, Ascot, Bulawayo, Zimbabwe,
[email protected] , [email protected], 1,2
Faculty of Engineering and the Built Environment, University of Johannesburg, South
Africa, [email protected], [email protected]
Keywords: Reconfigurable, Marula Nut Cracking Machine, Entrepreneurship, Appropriate
Technology
ABSTRACT
Local level Entrepreneurship is increasingly becoming loudly relevant to sustainable
economic development and job creation in developing countries much as it is for developed
economies. It has, especially, become an essential platform for self-sustenance of the
vulnerable countryside communities of Masendu and Chivi and the urban poor as they try to
cope with the recent global economic recession and as they strive to cope and reverse or
shake-off the negative effects of the general decay of the national economy of Zimbabwe over
the last decade in which unemployment levels still exceed 80%. Survival is still a key word in
the economy. Foreign direct investment had almost halted. This paper discusses the novel
concept of Reconfigurable Marula Nut Cracking Machine (RMNCM) design based-
entrepreneurship being undertaken at Chivi and Masendu wards in Zimbabwe. The paper
focuses on the contribution being made by the researchers in enhancing the sustainable
exploitation of the Marula (Agroforestry product abundant in the communities) fruit for
sustainable entrepreneurial operation by the economically vulnerable women and children in
the communities, through the designing of a RMNCM for development and utilisation in the
communities as an appropriate technology platform for rural communities business and
economic development. It then goes on to present the initiatives taken by the National
University of Science and Technology to develop a formal entrepreneurial culture to
maximise revenue realisation and employment generation The research team developed
concepts of a Reconfigurable Marula Nut Cracking Machine for sustainability compared to
with rudimentary technological platforms. Concept selection tools were used, after which the
machine operating parameters were determined. Formalised sustainable market accessing
structure was developed as cracking capacity and rate is now determinate. Thus encouraging
formal marula based enterprises development, community harmony and fruit value
maximisation.
1 INTRODUCTION
Sustainability is explained as the ability of a design to meeting the needs of the present
without compromising the ability of future generations to meet their own needs [1]. Thus, the
future economic livelihood of countryside dwellers descendants depends to a greater extent
on the economic strength which the current generation may manage to harness. The
promotion of rural enterprises is crucial for the achievement of broader development
objectives, including poverty alleviation, economic development and the promotion of more
2 Corresponding Author
172
democratic and pluralist societies in developing regions of the world, the Sub-Saharan Africa,
the SADC region and Zimbabwe communities in particular indeed. Transformation of
countryside (rural) economies from subsistence to market orientation and diversification into
activities based on the special advantages offered by locally available natural resources, for
producing high value and value added commodities is essential for improving the livelihoods
of the rural poor in the countryside regions of most developing economies [2]. Poverty is a
multifaceted phenomenon [3] and to overcome it requires a holistic perspective. Our
approach, accordingly, draws on theoretical the solutions will need to be broad-based, locally
focused, and interdisciplinary considerations from the fields of entrepreneurship,
environmental management, and development studies.
The underutilization of natural resources is in fact one of the main reasons for the persistence
of rural poverty and degradation of the resource base in the country. In this context, the
establishment of natural products enterprises provides tremendous opportunities. Thus this
research seeks to enhance the market and income generating oriented economic utilisation of
the Marula tree and its products by the countryside communities of Masendu and Chivi. This
is expected to improve the entrepreneurial capacity of the rural communities and life
enhancement for the community members involved. Surveys conducted in the zoom site
communities, [4] generated crucial information regarding the communities’ awareness levels
of the commercial value of the marula tree and the level of business they derived from the
valuable tree. In this report the researchers present the results of the work done at Chivi Ward
21 and Masendu Ward, through the Marula Nut Decortications Machine Design project.
Chivi Ward 21 is in Masvingo whilst Masendu Ward is in Matebeleland South, provinces of
Zimbabwe. The communities were conveniently selected, as zoom sites, for the project
deriving from the research experiences which one of the authors had been going through
since 2007 on another sponsored community development research work. The zoom site
communities are very similar in a many respects and are characterised by the following
attributes, on Table 1. The need for the Machine was then highlighted. Thus, the project came
up with a mechanisation platform for processing marula nut kernels in business level
quantities. This was deemed an appropriate technology platform by which the communities
can benefit through fostering sustainable economic development.
Table 1 Pertinent Characteristics of Chivi and Masendu Communities [5, 6, 7]
Community Characteristic Masendu Chivi
Rainfall Pattern Average 530 mm Average 530 mm
Drought Situation 3 years in 5 year period 3 years in 5 year period
Population density 70 people per km2 70 people per km
2
Average Landholding/Farmer 1.2 Ha 1.2 Ha
Agricultural Activity Level Subsistence Subsistence
Population 17 000 21 000
This research in essence sought to contribute and address the following Millennium
Development Goals (MDGs) in the zoom site communities of Chivi ward 21 and Masendu:
Goal 1: Eradicate extreme poverty and hunger; Goal 2: Achieve universal primary education;
Goal 3: Promote gender equality and empower women; Goal 6: Combat HIV/AIDS, malaria,
and other diseases and Goal 7: Ensure environmental sustainability.
173
2.0 LITERATURE REVIEW
The paper was based on related literature in Appropriate Technology, Entrepreneurship
development and Reconfigurable Machine Tool (RMT) systems design:
2.1 Appropriate Technology (AT)
Appropriate Technology (AT) relate to equipment and processes being used in various parts
of the world being suited to the local conditions. According to Hubbe [8] it is a concept
borrowed from the third world but is equally relevant to both the developing and developed
world. Wicklein [9] explains AT as a concept which embodies providing for human needs
with the least impact on the earth’s finite resources. Thus, AT has concern for people and the
environment much as it contributes to society, school aged children, vulnerable society
groups and to both developed and developing nations around the world. AT does not only
concern the developing economies [10]. Though the nuances of appropriate technology vary
between fields and applications, it is generally recognized as encompassing technological
choice and application that is small-scale, labor-intensive, energy-efficient, environmentally
sound, and locally controlled. According to Hazeltine and Bull [11] many modern-day
proponents of appropriate technology emphasize the technology as people-centered. The
criteria for assessing the appropriateness of technology, as provided by [12] and [13], entails
consideration of the following factors inter alia: Systems independence, Modernity image
projection, Individual versus collective technology base, cost of the technology, risk factors
of the technology, evolutionary capacity of the technology should reconfigurability be
required, single-purpose or multi-purpose of the technology.
Human capital is the defining factor in the growth of the creative and entrepreneurship sector,
[14]. In addition human capital requires skills and talent, entrepreneurial attitude, ingenuity
and motivation. Value creation and innovation through local business development are
essential means for the alleviation of poverty and preservation of the natural environment,
[15]). Creativity and creative communities may be the remaining enduring resources in the
developing world, [14].
2.3 Entrepreneurship
Entrepreneurship is increasingly relevant to economic output and job creation in both
developed and developing countries, [16]. Entrepreneurship is the driving force behind the
growth in the modern economy and it is becoming increasingly relevant to economic output
and labour employment. Much more desirable it is with rural communities like the zoom sites
identified in this project.
2.4 Sustainable Development
Sustainable development relate to meeting the needs of the present without compromising the
ability of future generations to meet their own needs, [17] and [18]. Thus sustainable
exploitation of the marula fruit today in Chivi and Mesendu will ensure continued effective
benefit of future generations from the activities of the current generations.
2.5 Reconfigurable Machine Tool (RMT)
Manufacturing equipment need reconfigurability due to changes in needs or technological
obsolescence. Reconfigurable machine tools are characterised by adjustability, convertibility,
recoverability, modularity of parts and serviceability [19].
174
3.0 METHODOLOGY
Primary data was gathered through semi-structured interview and group surveys conducted at
the two zoom sites. Information in terms of volumes and harvest yields was required to
determine the parameters of the machine that was to be developed. Secondary data provided
details on how a reconfigurable Marula nut decortications machine would be designed and
built.
4.0 RESULTS AND DISCUSSIONS
Results of the design process and the outcome are presented as following.
4.1 Design Process Results
Six design concepts were considered as outlined on the concept screening and scoring
matrices below: (A - Cracking and conveyance; B – Sprocket Carrier and roller Wheels; C –
Meshing Sprocket Crushers; D - Four Grooved rollers with Tongue; E - Adjustable Sprocket
Rollers and F – Fingered Roller Crushers). The concepts screening and scoring iterative
process [20] helped the team in determining the most optimum concept for development out
of the six.
4.1.1 Concept Screening
Concept screening process was premised around the desired performance parameters such as:
copes with stresses caused by the load; generates less cracked kernels; less complicated
motion of parts; availability of selection material range; form and size of the parts;
frictional resistance and lubrication; safety of operator and system dynamic stability;
use of standard parts; manufacturing workshop facilities capability; ease with which
assembled; convenient and economical features; project capital investment costs (US$);
projected maintainability and costs; versatility towards automation; general considerations in
machine design. The concepts considered were A, B, C, D, E and F, while the net scores were
7, 5, 0, 1, 2, -1 respectively and concept C was taken as the bench mark concept. Combining
concepts C, D and E to yield a new concept CDE which was considered in the second round.
Concept F is discarded at the initial stage.
Concept A was selected for further development and the schematic layout of the Machine
cracking mechanism as developed is shown on Concept A shown in Figure 1 which presents
some of the concepts.
Concept A Concept B Concept C
Figure 1 Some of the Concepts Considered
4.1.2 Concept Scoring Matrix
The concept selected for further analysis were further screened by analyzing them using a
weighted scoring screen process where the result was intended to finding the highest scoring
175
design for further development. Sj =
n
i
ijjrW1
, Where rij – raw rating of concept j for the ith
criterion, Wi – weighting for ith criterion, n – number of criteria and Sj – total score for
concept j, [20]. As such concept A was selected for development implementation. Concept B
is recommended for further revision whereas concept CDE was discarded.
Table 3 Concept scoring matrix
Selection criteria
Concepts
Weight
(%)
A B
(Reference)
CDE
Rating WS Rating WS Rating WS
Copes with Stresses caused by the Load 0.05 4 0.2 3 0.15 3 0.15
Generates less cracked kernels 0.08 5 0.4 3 0.12 2 0.16
Less complicated motion of Parts 0.02 4 0.08 3 0.06 2 0.04
Availability of Selection Material range 0.03 3 0.09 3 0.09 2 0.06
Form and Size of the Parts 0.04 2 0.08 3 0.12 1 0.04
Frictional Resistance and Lubrication 0.02 2 0.04 3 0.06 2 0.04
Safety of Operator and system dynamic
stability
0.08 4 0.32 3 0.24 3 0.24
Use of Standard Parts 0.04 2 0.08 3 0.12 2 0.08
Manufacturing Workshop Facilities
capability
0.1 5 0.5 3 0.3 2 0.2
Ease with which assembled 0.05 4 0.2 3 0.15 2 0.1
Convenient and Economical Features 0.1 3 0.3 3 0.3 2 0.2
Project capital investment costs (US$) 0.2 5 1 3 0.6 3 0.6
Projected maintainability and costs 0.06 4 0.24 3 0.24 4 0.24
Versatility towards automation 0.08 3 0.24 3 0.24 2 0.16
General Considerations in Machine
Design
0.05 3 0.15 3 0.15 2 0.1
Total Score
Rank
Continue?
1
3.92
1
Yes
2.84
2
Rev
2.61
3
No
Note: WS - means weighted score: Rev - means revise
4.1.3 Cost and Payback Period of the Machine
The marula decortications machine was estimated to cost US$4982.00, in Zimbabwe and the
determined payback period is 9 months to the communities that invest in it.
5.0 COMMUNITY BASED ENTREPRENEURSHIP AND POVERTY
REDUCTION INITIATIVE IMPACT POINTS
i) Food security: Projected quantifiable marula products serves an essential function as
food security for the majority countryside human population because semi-domesticated and
wild species provide a breadth of genetic resources that is critical for enabling food
productivity, meeting the world s food needs, and creating food varieties that are adapted to
dynamic, local conditions. Thus mechanising the community ability to produce the kernels
will enhance productivity and help towards food security in the community.
ii) Employment and Income: Existing sustainable marula nut based self-employment in
the communities is shown in Figure 2. Projected employment from the structured marula
business is 1200 people in Masendu and 1050 people in Chivi respectively.
176
Figure 2 Number of Community
Stakeholders in Marula nut business
activities
Figure 3 Income Levels at Various stages of
Project
iii) The income produced from the sale of marula kernel products is currently
insignificant at US$175/month for a cracking team of 15 families and is projected to be
US$17500/month deriving from the machine’s cracking capacity of 1* bucket (20 litre)/hour
over an 8 hour day and working through an average of 25 working days a month, between
March 2011 and the December of 2012, equivalent to US$210000 per year. These are values
based, prudently, on the current village level selling prices for the kernels. In real practice
when the structured business process is taking place and the processes of entrepreneurship are
commenced as is the ultimate goal of the project, the commercial selling price of
US$3.90/250 ml mug will be the base price of the kernels. Thus in real terms
80*3.90*8*25*12 = US$748800/year will be the trade realisation from the marula kernels
business engagement in the respective communities when focusing on a cracking team of 15
people as a start base point [4].
iv) Health improvements: Taking good care of the medicinal marula tree after realising
more value from it by the community helps improve the biodiversity in the zoom site
communities. A diversity of food sources is now available in the participants’s families. This
is good for health improvement as well. The marula tree is being used for medical care
among other many uses to the communities in Chivi and Masendu.
v) Community vulnerability: Immorality, social delinquency, HIV/AIDS and droughts
tend to be directly proportionate with incomes improvement especially for once economically
disadvantaged communities. Such hazards are intensified in frequency and impact strongly in
rural communities. Thus project will reduce risk for communities.
vi) Quality of life: Marula business employment, based on the income levels presented
above is higher than the rest of the local community economy activities so far. The
availability of education and training will be improved, providing personal development
opportunities for the families’ children.
vii) Ecosystem and Environmental services: Ecosystem services provide the
fundamental basis for life and the productive activities of the majority of human enterprise.
Forest, grassland, and all other ecosystems provide the water generation and purification;
175 17500
748800
0100000200000300000400000500000600000700000800000
Income levelon Project start
(US$)
IncomeDerivation
Projection onVillage
prices(US$)
ProjectedProject Income
Goal onbusiness
prices(US$)
Val
ue
US$
/ a
nn
um
0
200
400
600
800
1000
1200
CurrentlyBennefiting
Projectedproject goal
177
replenishment of soil fertility; waste treatment; nutrient cycling; and prevention of erosion,
floods, and drought that are essential to all human livelihoods, especially those of poor people
who are less buffered from disruption of these services. Entrepreneurship and Creative
industries are often associated with a high quality environment and the development of social
responsibility. Thus, anticipation is high that the research work will positively impact on the
ecosystem and environmental management in the Chivi and Masendu communities in long
term.
viii) Social inclusion, Cultural diversity and Spiritual value: The marula tree and its
products were found to be of significant cultural and spiritual value in Masendu and Chivi.
As such conflicts always arise around the purported violations of these by some of the
community members. This normally derives from the fact that these values are not standard
across the society. As such projecting a much more economic sense of value of the marula
tree, from which people would now be doing business would help the preservation of the tree.
Thus, enhancing the attendant cultural and spiritual held values from the tree by the
community. In short, new opportunities for work are opened to those that were excluded with
the market oriented utilisation of Marula. The creation and operation of Community-based
organisations (as the marula clubs will work) help strengthen the communities’ ties.
Ultimately the majority disadvantaged poor people in the zoom site communities are able to
assess the value of their heritage and use it to derive economic and social benefit.
ix) Skills Development for Local Artisans and Business Entrepreneurship Trained
and Empowered: The development of the Marula Decortications Machine will be extended
to use community level local artisans. These will be trained in the basic maintenance of the
machine, fabrication skills and it is anticipated that they will engage in continued business of
fabricating more of the machines, under the guidance of the university level researchers.
6.0 CONCLUSION
The researchers maintain that in this emerging form of entrepreneurship, typically rooted in
community culture, natural and social capital is integral and inseparable from economic
considerations. Transforming the community into an entrepreneurship and enterprise zone is
feasible with the application of appropriate technology. The paper set out to show the
development of machine under appropriate technology that will help generate revenue for the
two communities through the sale of marula nuts. Future work on this project will be the need
to automating the material handling system and the separation of kernels and the chaff on the
Marula nut cracking machine.
7.0 ACKNOWLEDGEMENTS
This work is supported by the National University of Science and Technology, Zimbabwe,
Research Board Grant RB/26/10.
REFERENCES
[1] Adams W M, (2006), The Future of Sustainability: Re-thinking Environment and
Development in the Twenty-first Century, http://cmsdata.iucn.org/downloads
/iucn_future_of _ sustainability .pdf, (accessed on 2 June 2012)
[2] ANSAB (2010), Entrepreneurship Development of Natural Resources Dependent
Communities, ISBN_13: 9789993379669, Asia Network for Sustainable Agriculture and
Bioresources. Kathmandu, Nepal
[3] Narayan-Parker, D (2000), Voices of the poor: Can anyone hear us? New York: Published
by Oxford University Press for the World Bank, Oxford.
178
[4] Tayisepi N and Mhlanga S, (2012), Marula Nut Decortications Machine Development:
Growing Industry and Sustainable Rural Livelihoods in Chivi and Masendu Districts in
Zimbabwe, CSBD Conference, 15-16 May 2012, University of Johannesburg Faculty of
management, Johannesburg
[5] Moyo M and Khombe C.T, (2007) Masendu Zoom site; Community Consultative Report,
Unpublished
[6] Goriwondo W M, Zimwara D, and Tayisepi N (2008), Using wind energy for harvesting
and providing sustainable safe groundwater for a Rural Community in the Masendu Ward
in Zimbabwe, Proceedings of Conference on Renewable Energy, Water and Sanitation,
Kigali, Rwanda.
[7] Zimstats CSO (2003) Census 2002: Zimbabwe National Report – Preliminary Report,
Central Statistical Office, Harare.
[8] [8] Hubbe M A, (2007), Appropriate Technology for Sustainability in an age of
Renewables, BioResources 2(2), 146- 147,
(http://www.ncsu.edu/bioresources/BioRes_02/BioRes_02_2_146_147_Hubbe_Appropri
ateTechnology.pdf), accessed 22 July 2012
[9] Wicklein R C, (2004), Design Criteria for sustainable Development in Appropriate
Technology: Technology as if People Matter, University of Georgia, Georgia,
http://www.iteaconnect.org/Conference/PATT/PATT14/Wicklein.pdf, accessed on 10
May 2012
[10] Ellis G and Hanson B, (1989), Evaluating Appropriate Technology in Practice,
Journal of Contemporary Asia, 19(1), 33 – 47
[11] Hazeltine B and Bull C, (1999), appropriate Technology: Tools, Choices and
Implications, Academic Press, New York, 3, ISBN 0-12-33519-1,
http://www.amazon.com/dp/0123351901, accessed on 8 July 2012
[12] Ghosh P K, (1984), Appropriate Technology in Third World Development,
Greenwood Press, Westport C T,
http://www.iteaconnect.org/Conference/PATT/PATT14/Wicklein.pdf, accessed on 15
May 2012
[13] Jequier N, (1979), Appropriate Technology: Some Criteria, as referred in Bhalla A S,
Towards Global Action for Appropriate Technology, 1-22, Pergamon press, Oxford
[14] Wijngaarde I, (2006) Creative Industries and Micro & Small Scale Enterprise
Development: A Contribution to Poverty Alleviation: Private Sector Development
Branch Programme Development and Technical Cooperation Division, Project
XP/RAS/05/002, UNIDO and UNESCO, Vienna, Austria
[15] Peredo A M, Chrisman J J (2008), Toward a Theory of Community-Based
Enterprise, Academy of Management Journal, 31(2), College of Business and Industry,
Mississippi State University
[16] Sondakh D F and Rajah K K, (2007), Developing an Entrepreneurship Culture: The
Greenwich Experience
[17] Ziout A, ElMaraghy W H, and Altarazi S, (2011), A Model for Sustainability
Assessment of Manufacturing System Reuse: Case Study in a Developing Country, 44th
CIRP
[18] Brundtland Commission, (1987), The World Commission on Environment and
Development, Oxford University Press, Oxford
[19] Butala P and Sluga A, (2002), Morphology of reconfigurable manufacturing systems,
Proceedings of the 4th International Workshop on Emergent Synthesis IWES '02, Kobe
University, Japan, May 9-10, 2002. Kobe: University, 2002, pp. 127-134
[20] Ulrich K T and Eppinger S D, (2010), Product Design and Development , McGraw-
Hill Publishers, Minnesota
179
A Strategy for Socially Relevant Computing John Trimble,
Systems and Computer Science Department Howard University,
Washington DC 20059, USA
Keywords: Social relevance, technology policy, curriculum development
Abstract
This paper is based on the academic work of the investigator over the past ten years
that includes curriculum development at Howard University as well as universities in
Zimbabwe, South Africa and Rwanda. The focus is directing the development of the
computing discipline in a people-centered manner. In developing a new program there is the
opportunity to shape the focus to make the curriculum most socially relevant. This was the
case at Umutara Polytechnic University in Nyagatare Rwanda, with a new program
developed in 2006-7. At Howard University the strategy was to infuse curriculum content in
existing courses at all levels of the undergraduate program. When a new PhD program was
developed in computer science at Howard a socially relevant computing component was
developed as a requirement for all students.
The methodology used defined a theoretical justification and an organizational
approach. The theoretical justification consist of a philosophical component that seeks to
clarify ‘what is’ socially relevant computing and an ideological component that seeks to link
socially relevant computing to the social and economic interests of a broad population. The
organizational approach is multidimensional crossing educational levels, educational
institutions and professional organizations.
The National Science Foundation (NSF) funded two workshops on Socially Relevant
Computing. The inputs, dynamics and outputs of these workshops are examined as part of
this effort. This paper details the process of advancing socially relevant computing as well as
the impact this process is having on lecturers as well as students. Recommendations for
extending these efforts are an essential component of this paper.
BACKGROUND
Most computer science programs across North America follow the Association of
Computing Machinery (ACM) IEEE Computer Society guidelines for the content of the
undergraduate (Bachelor of Science) degree in computer science. Many programs in Europe
are patterned after these same guidelines. Programs in Africa are more recent but were
established following these guidelines or emulating particular programs developed in North
America or Europe.
Howard University followed the ACM IEEE Computer Society standards in
developing their computer science program. They also have followed the ABET
accreditation process, which is an international accreditation board for engineering and
computer science established in 1932. “Currently, ABET accredits over 3,100 programs at
more than 600 colleges and universities worldwide.”[1] While offering an ABET accredited
computer science program, the Bachelor’s degree includes a set of system engineering
courses giving Howard’s program a unique character. One of the ABET approved objectives
of the computer science program at Howard is for a student to be aware of ethical and societal
concerns relating to computers in society and to be able to apply this knowledge in the
conduct of their careers. One of the program’s expected outcomes is for a student to gain an
understanding of professional, ethical, legal, security and social issues and responsibilities.
180
However, current ACM IEEE Computer Science guidelines only require a minimum of 3
contact hours of material directly related to social context [1].
English based computer science programs in Africa largely mirror the programs in
North America and Britain. The majority of textbooks used in Africa are written in the USA
and Britain. Many of the professors and senior lecturers have received training in North
America and Britain. Therefore, it is not unusual that the curriculum and textbooks are based
on western standards. US based programs like that at Howard University and African
programs (like that at University of Western Cape and Umutara Polytechnic) have two major
differences. Howard University requires more general education courses and non-technical
electives and African programs grade courses based largely on the results of highly regulated
end of term examinations.
METHODOLOGY
The methodology used defines a theoretical justification and an organizational
approach. The theoretical justification consist of a philosophical component that seeks to
clarify ‘what is’ socially relevant computing and an ideological component that seeks to link
socially relevant computing to the social and economic interests of a broad population. The
organizational approach is multidimensional crossing educational levels, educational
institutions and professional organizations.
The theoretical justification provides the ethical and economic basic for educational
institutions and professional organizations to support the organizational approach
implemented in this effort. The organizational approach requires notable changes in the
educational institutions’ curriculum and the professional organizations’ programs. The extent
to which these organizations and institutions are willing to change and the pace of change is a
validation of the theoretical justification.
An assessment of the success of the organizational approach can serve as justification
for extending implementation of the particular elements of the organizational approach. The
feedback that educational and organizational resources are well utilized is incentive to not
only continue the elements of the organizational approach but to further develop those that
receive the most favorable response.
DISCUSSION AND RESULTS
There are contrasting views on what is socially relevant computing. One popular
view of socially relevant computing forwarded [2] focuses on computing applications that
appeal to students. The use of applications and examples that students can identify with,
enjoy and find a sense of accomplishment will attract and retain more students to the
computing fields. Students are more socially engaged during the learning process when they
feel examples and applications used in the educational process are more relevant. These
more engaged students are more committed to the learning process since they enjoy it more.
Not only will the number of trained computing specialist increase but their skill level and
creativity level will also increase.
Another view, of socially relevant computing, highlights applications and examples
that directly benefit the welfare of a particular population or the planet itself [3]. Many of
these applications also appeal to a broad population of students and potential students.
However, that is a secondary benefit. Generally the identification of meaningful applications
and examples is linked to the goals of the dominant institutions. An altruistic element in
these institutions may drive these institutions to promote computing projects that may not be
market based but instead make a contribution to the social welfare of some group of citizens.
A particular offshoot of this social welfare view highlights computing that impacts
basic needs of the most disadvantaged populations. This approach is not committed to the
181
dominant institutions. In fact, it seeks to highlight the most oppressed populations and
identify computing solutions that will empower them. This approach treats computing as a
discipline to empower the populations that suffer the most from natural or human made
obstacles. This humanist approach to socially relevant computing also addresses the balance
between human consumption and utilization of the planet’s resources. It is a long range
approach concerned with the welfare of the planet and all of her people.
This approach seeks out revolutionary technical and systemic changes in the use of
computing that often run counter to the interest of the dominant institutions locally and
globally. However, this approach will maximize the benefit to the larger population. Using
computing to meet the needs of the broader population is complementary to the broader field
of appropriate technology and a component of this broader field. The goal of empowering
people is to improve their quality of life. An example of socially relevant computing is the
development of rural tele-centers. The mobile telephone companies find it unprofitable to
provide service in rural areas. However, a government backed plan to provide solar powered
computer network connected to the internet is empowerment for the rural community.
Using computing to better satisfy the basic needs of people, improves their social
welfare, setting the tone for their further involvement in developing and contributing to
society’s advancement. Having cleared the hurdle of basic needs, options for further
development open up. Increasing the size of the empowered population advances the cause
of democracy. An empowered population is in a better position to demand that its political,
economic and social institutions and leader make policies and decisions that are consistent
with advancing the quality of life of the broader world population.
Curriculum Development and Research in Zimbabwe
The author served as a Senior Fulbright Professor at the National University of
Science and Technology (NUST) from 2003-2004 in the computer science department. In
addition to teaching courses, he coordinated a review and revision of the curriculum. A
major concern was assuring that the curriculum, while consistent with international standards
addressed the particular needs of Zimbabwe. This led to the emphasis on Database systems,
decision support systems, expert systems and modeling and simulation and required courses
at the undergraduate level.
The author developed and taught undergraduate and graduate courses in Artificial
Intelligence, Expert Systems, and Modeling and Simulation. The Modeling and Simulation
course addressed both discrete simulation and system dynamics. These courses provide the
students with 1) the solid theoretical background needed to support decision making and 2)
the skills using computer based tools that can assist in the development of people-centered
computing applications.
All fourth year undergraduate students have final year projects and all second year
Masters students have to complete a Thesis. Consistent with the major needs of the country
many students selected Database related projects and theses. Several students worked with
me on expert systems, system dynamics, intelligent systems and simulation projects. The two
most notable projects involved an expert system to monitor the care of goats; and the
development of an ontology for appropriate technology implemented with a database system.
A unique feature of the NUST computer science program is that all third year students
spend the full year on attachment with an industry or government partner [4]. Academic
advisors make two visits during the year to all students site of employment meeting with both
students and their supervisors. The strong partnerships developed in this process assure a
meaningful experience for the student consistent with the needs of the government and
industry partners. At the end of the year each student must submit a comprehensive report
182
that must be approved by their onsite supervisor and graded by the academic advisor. The
student will receive a full year of academic credit for this attachment experience.
Curriculum Development in Rwanda
Between 2006 and 2008, the author served as the Dean of Information and
Communication Technology (ICT) at Umutara Polytechnic University. A major
responsibility was the design, implementation and accreditation of the ICT curriculum. A
major concern nationally was preparing students with the proper experiences to meet the
needs of industry and government. Three courses were created for all first year students to
address a people-centered focus: Critical thinking and knowledge systems, Appropriate
Technology, and Introduction to Political economy and development economics.
Rwanda did not have a full year attachment program like Zimbabwe. After meetings
with government agencies and the university administration, approval was given to
implement a six to eight month internship process following the first semester of the third
year. This program was implemented mid-year 2008. Due to the limited number of positions
available with government and industry partners the program was implemented at two levels.
Fulltime 6-8 month positions were available to the top academic performing students. Other
students, enrolled in courses the second semester and conducted a part-time internship at
Umutara Polytechnic, local High schools, the local Technology center or local government
offices in Nyagatare.
After an assessment of projected ICT needs for Rwanda two tracks for ICT Bachelor
degree students were developed. The tracks only differ in the fourth year courses that
students are required to take. Table I indicates the proposed courses.
‘Information and Knowledge Systems’ Track ‘Computing Technology’ track
Knowledge Acquisition and Management: Theory & Practice
Microprocessor design and applications
Operations Research I Digital systems and controls
System Dynamics and Decision Making Telecommunications: theory and practice
Data Mining & statistical analysis Information, computer and network security
Artificial Intelligence and Expert Systems Wireless communications
Research methods, ethics and professional conduct
Research methods, ethics and professional conduct
Operations Research II Network & System Administration Computation theory, formal languages and automata theory
Computation theory, formal languages and automata theory
Final Project I Final Project I
Final Project II Final Project II
Table 1. Two Tracks for Bachelor of ICT
Curriculum Development at Howard University
In 1997, members of the African Students Association met with the Howard
University administration to address the need for the engineering and computer science
curriculum to better prepare African students for the needs of their home countries. As a
result of this and previous work of the author a Howard University Project on Appropriate
Technology (HUPAT) was established. The first task of this HUPAT was to develop
curriculum material for the Introduction to Engineering Design course required of all
engineering and computer science 1st year students. The introduced materials were designed
to infuse social relevance and enhance the critical thinking of the students.
183
In 2011 a plan to implement a PhD program in computer science was presented to the
President and Board of Trustees of Howard University and approved. A key feature of the
proposal was the emphasis on socially relevant computing. This was very consistent with the
legacy of Howard University. All PhD students would be required to take a course on
socially relevant computing. All PhD proposals submitted must indicate the social relevance
of the proposed work. The first intact of PhD students in computer science was August 2012.
First three conferences on appropriate technology
A milestone in advancing socially relevant computing came with the First
International Conference on Appropriate Technology (1st ICAT) in 2004 in Bulawayo
Zimbabwe. A track was devoted to appropriate computing and knowledge management.
Earlier efforts such as a workshop on appropriate technology in 1998 and a conference on
appropriate technology in 1999 (both held at Howard University) had presentations that
addressed people-centered computing. However the 1st ICAT was the first international
effort that consciously linked appropriate technology to socially relevant computing
involving academics in underdeveloped countries in Africa and the Caribbean. This success
was followed by three other ICAT. The 2nd
ICAT was held in 2006 again in Bulawayo
Zimbabwe. The 3rd
ICAT was held in Kigali Rwanda in 2008 and the 4th
ICAT was held in
Accra Ghana. Each conference had a different focus, but each had a section related to
socially relevant computing.
Two workshops on socially relevant computing
Funds from the National Science Foundation (NSF) in the USA allowed the
organization of two workshops on socially relevant computing. The first was held in 2010 in
Accra Ghana immediately before the 4th
ICAT. Many of the workshop participants stayed
over to the 4th
ICAT gaining a better understanding of the linkage between socially relevant
computing and appropriate technology. The second workshop on socially relevant computing
was held at the University of Pretoria in South Africa in August 2011. This was independent
of the appropriate technology conferences but built on the work of the first workshop, while
expanding geographic participants.
Outcomes of this series of workshops included: 1) multiple presentations at the 4th
International conference on appropriate technology; 2) a workshop by a Howard University
graduate student on ‘Socially Relevant Technologies’ as well as a presentation by the author
at the National Conference of the National Technical Association (NTA); 3) a paper
published in the National Technical Association Journal; and a paper presented at the
Workshop on Knowledge Management Capacity in Africa held in January 2012 in Khartoum
Sudan.[5]
Another outcome of the 1st workshop was the formation of a knowledge management
working group. Dr. Gada Kadoda took the lead in furthering the work in knowledge
management.
Table 2 highlights the content, outcomes and participants of the two workshops. In
both cases most of the participants were lecturers or professors in computer science or
information science at the university level that were actively engaged in research. At both
workshops, participants acknowledged that one motivation for socially relevant computing
was to attract more highly qualified and motivated students.
184
Workshop #1 Accra Ghana, November
2010
Workshop #2 Pretoria, August 2011
Sessions on: 1)Information assurance and
computer and network security, 2) Computer
Based educational services,3) Humanitarian /
open source software, 4) Decision support:
expert systems, operations research, and
knowledge management, and 5) Current
Computing Curriculum models
Sessions on: 1) Information assurance and
computer /network security, 2) Curriculum
for socially relevant computing, 3) Humanitarian / open source software, 4) Remote delivery of computing services, 5) Computer Based educational services, 6) Decision support, and 7) global dimension of
computing education
Focus of Outcome – Group #1: Knowledge
management system for the Volta basin;
Group #2: Bringing cost effective learning
from everywhere to anyone;
Group #3: Challenges: Privacy, Profiling,
actual data from the criminals, the social
landscape of Ghana internet cafes
Focus of Outcome - (1) to identify effective
learning models that incorporate a global
dimension in socially relevant computing
education; and (2) to identify the
infrastructure and resource requirements
needed to sustain a global socially relevant
computing education program.
Range of participants – 6 USA institutions,
3 HBCUs, 10 African Universities
Range of participants – 3 HBCUs, 7
African Universities, CIO of SASSA
Table 2: Highlights of Socially Relevant Computing Workshops held in 2010 and 2011
Under Dr. Kadoda’s leadership an international conference on knowledge
management was organized in Khartoum Sudan in January 2012. A wide range of social,
educational and culture needs were addressed with the application and development of
knowledge management. Participants from the socially relevant computing workshops and
the ICATs welcomed the opportunity to focus on applications in knowledge management of
social value. An important outcome of this effort was the organization of ongoing knowledge
management organization based in the Sudan - the Sudanese Knowledge Society. Dr.
Kadoda currently serves as president.
The National Technical Association (NTA) is the oldest Black technical organization.
It is based in Washington DC with chapters across the USA. NTA was incorporated in the
state of Illinois in 1926 and for over eight decades has served as the voice of minority
technical professionals. [6] Each year NTA organizes a national conference for its
professional members, students and concerned professionals across a range of disciplines. At
the past two conferences the author has presented papers relating socially relevant computing
and appropriate technology to a broad audience of technical professionals and students. In
last year’s issue of the NTA Journal the author presented an article computer based decision
support system for climate change [7].
“The Association of Computer/Information Sciences and Engineering Departments at
Minority Institutions (ADMI) was founded in August 1989. It was established as a national
organization dedicated to exploring and providing remedies to the educational issues in
computer/information science and computer engineering that confront minority institutions of
higher education.”[8] Increasing the relevance of computing and its appeal to minority
students is an ongoing concern of ADMI. The author has presented information concerning
appropriate technology and people-centered computing at the last three national conference of
ADMI. As an active member of the Executive Board of ADMI, the author has been able to
infuse concerns over socially relevant computing into ADMI’s program. ADMI members
were invited to participate in the first socially relevant computing workshop in Accra. Three
ADMI schools participated – Howard University (HU), Jackson State University and the
185
University of the District of Columbia (UDC). ADMI served as a co-sponsor for the 2nd
workshop on socially relevant computing hosted at the University of Pretoria. Three ADMI
schools presented talks – HU, UDC, and Spelman College.
Conclusions and future efforts
At Howard University, these efforts have led to inputs into Introduction to
Engineering Design, and Introduction to Systems and Computer Science. These two courses
are required first year courses for all undergraduate students in the computer science
program. The socially relevant computing component in the Introduction to systems and
computer science is linked to the ABET requirement on Computer Ethics. It fulfills both the
ABET and ACM IEEE Computer Science Curriculum standards. An evaluation of this effort
will be the basic of a future presentation to SIGCSE (Special Interest Group in Computer
Science Education).
The first intake of PhD students in computer Science joined Howard University this
year. A new course for graduate students on socially relevant computing is being designed
and will be offered this coming year. This will be the basic for establishing a standard for
addressing the socially relevant computing content of all PhD dissertations. This effort will
set Howard University’s program apart from others in the organized effort to make all
research in computer science address the people-centered dimension of computing.
The efforts of the 1st workshop on socially relevant computing and the ongoing work
in South Africa have resulted in identifying several researchers in mobile application
development. They have committed to developing a Workshop and Hackathon on ‘Mobile
Application development for Africa’s Needs’. It is currently scheduled in conjunction with
the 5th
ICAT this November 2012. This will link curriculum development efforts with
research in mobile application development and will serve to expand the base of lecturers and
advanced students engaged in the computing sub-discipline.
Collaboration between Howard University and African universities is being extended
through several Memorandum of Understandings (MOUs) recently established with
University of Pretoria (UP), University of the Western Cape (UWC), University of Fort Hare,
University of KwaZula-Natal and Tshwane University of Technology (TUT). The Howard
University computer science department has been engaged in work with all five universities.
UP is part of the collaborative effort with Howard to organize the workshop and Hackathon
on mobile application development for African needs. Howard University is working with
TUT on using systems dynamics to address a range of societal issues. The author will be
serving as a visiting professor (joint appointment) with the National University of Science
and Technology (NUST) in Zimbabwe. One immediate collaborative project is the
ICT4Africa international conference scheduled for February 2013. We will build on this
effort to extend our socially relevant computing network in Africa.
ADMI plays an ongoing role in defining and developing curriculum in computing for
minority institutions across the USA. The involvement of ADMI in our socially relevant
computing agenda started with participation in the first socially relevant computing workshop
and extended to co-sponsoring the second socially relevant computing workshop. For the
future ADMI has extended their commitment through its organizational members
commitment to present papers at the upcoming 5th
ICAT. This is the basic for curriculum
development and collaborative research on a global scale. NTA has committed to an
increased involvement in the socially relevant computing agenda through its commitment to
appropriate technology. The NTA conference and Journal contained presentations on
appropriate technology as well as coverage of the 4th
ICAT.[8] The upcoming NTA
conference this 2012 as well as the journal are scheduled to have coverage of the Sudan
186
conference on Knowledge management, the 5th
ICAT as well as an article on technology
policy that promotes socially relevant computing.[9, 10]
Acknowledgements
The National Science Foundation helped fund the workshops on Socially Relevant
Computing held in Accra Ghana and Pretoria South Africa. We acknowledge the support of
the National Technical Association and the Association of Computer/ Information Sciences
and Engineering Departments at Minority Institutions (ADMI) is our efforts to involve
institutions in advancing socially relevant computing.
References
[1] ABET, (last visit September 2, 2012), www.abet.org/history
[2] Buckley, Michael, J Nordinger, D Subramanian, “Socially Relevant Computing”,
SIGCSE’08, Month 1–2, 2008, Portland, Oregon, U.S.A.
[3] Microsoft Research, Socially Relevant Computing, our Health, our Knowledge, our
Planet, research.microsoft.com/collaboration, 2012
[4] NUST, Yearbook 2003/2004-2004/2005 General Information & Regulations, Published
by the Information and Public relations Office, National University of Science and
Technology, Bulawayo, Zimbabwe
[4] Trimble, John, Report on National Science Foundation (NSF) workshops on: “Socially
Relevant Computing: Building USA and African Partnerships”, NSF, 2011
[5] History of the National Technical Association, (last visit September 2, 2012)
www.ntaonline.org/aboutus/history.html
[6] Trimble, John and G. Jenkins, A Framework for Interactive Decision Support and
Education On Climate Change, Journal of the National Technical Association, Vol. 81, No.1,
2011, p.38-46
[7] ADMI, What is ADMI? (last visit September 2, 2012) www.admiusa.org
[8] Wright, Albert, Keeping the Eye on the Prize – One Goal, One Team, Several Players,
Journal of the National Technical Association, Vol. 81, No.1, 2011, p. 9-13
[9] Carwell, Hattie, NTA Collaborates in Knowledge Management Workshop in the Sudan,
Journal of the National Technical Association, Vol. 82, No.1, 2012, p.6
[10] Trimble, John, Comparative Paradigms in the Examination of Technology Policy,
Journal of the National Technical Association, Vol. 82, No.1, 2012, p.30-37
187
Computerized Inventory Management for a Manufacturing Industry: Case
Study in Nigeria
*1E.S. Owoeye,
2S.B. Adejuyigbe,
3B.O. Bolaji and
4A.F. Adekoya
1, 2, 3: Mechanical Engineering Department, Federal University of Agriculture, Abeokuta
4: Computer Science Department, Federal University of Agriculture, Abeokuta
Tel: 234(0)8038664815 Email:[email protected]
*1Author for Correspondence
Keywords: Computerized, Inventory, Inventory management, manual inventory
management, manufacturing industry
Abstract
Various authors have suggested that the cost of purchasing and holding inventory can
account for as much as 60-80% of the total cost of a product or service. Usually, only a few
(about 10% by number) contribute to 70-80% of locked up inventory or 70-80% of
consumption value or their availability is vital for maintenance or the process. Hence, the
need for an effective and efficient inventory management is germane to any manufacturing
industry. This paper presents a software, ‘manInvent’, an interactive system developed using
visual basic 6.0, with a view to reduce manual interaction with the inventory management of
a Nigerian manufacturing industry. Working with 5 years production data of the industry, the
objective of the software ‘manInvent’ was validated with respect to the manual inventory
system of the industry, and the result is shown.
Introduction
We all hold money, and one wonders if we all know the reasons we hold it. A Social science
subject objectively gave us three reasons why we keep money, and they are: Precautionary
motive, Transactional motive and Speculative motive. Like money, companies keep
inventory for these reasons stated above and even more. Inventory is any resource held by the
organization (in this case, manufacturing industry) for future use. Inventory management is
the act of keeping track of the quantity of material and number of item that should be and are
presently in inventory at any time; supplies data required by other diameters of manufacturing
cycle and links manufacturing to costing, book keeping and general manufacturing. Inventory
management also often referred to as inventory control can be referred to as the actual steps
taken to maintain proper stock level in raw materials and finished goods. Considering the
importance of competent inventory management in any manufacturing industry, the need for
a computerized inventory management is therefore necessary for an active and productive
manufacturing industry so as to enhance a better output. For this reason, this research is
undertaken so as to computerize inventory management in an existing industry in Nigeria.
Computerized Inventory Management basically involves the use of computer technologies to
control and manage inventory. The usefulness of computer cannot be over emphasised,
especially when employed in solving problems.
Objectives
This paper presents the computerization of the inventory management of a Nigerian
manufacturing industry, which will serve as a model in developing computer software for
other manufacturing industries. The specific objectives of the project are to: investigate the
level of inventory management in manufacturing industry; develop a computer modelling for
Inventory management in manufacturing industry and; validate the software model developed
using a case study manufacturing industry.
188
Methodology
Various steps were involved in the development of the software, and achievement of the
objectives of the project work. The steps involved are represented diagrammatically in figure
i.
Figure i: Solution Procedure
Figure i shows the Solution procedure. The solution procedure is an overview of how the
researcher went about achieving the goals of the research work.
Figure ii: Flow of Materials through production cycle.(Chandra, 2009)
189
Figure ii shows the flow of materials through the production cycle in a typical manufacturing
industry. The flow of materials through the production cycle is simply the process flow of
materials through the receiving stage to the final stage of delivery of the finished product.
Figure iii: Cost Relationship for EOQ model (Samuels et al, 1998)
Figure iii shows the cost relationship for the EOQ (Economic Order Quantity) model. The
EOQ model is used to determine an order size that will minimize the inventory cost and is
obtained using a mathematical formula which shows the relationships between the ordering
cost, holding cost, forecasted demand and the best time to make a reorder point among other
minor variables.
Figure iv: Classic EOQ Pattern (Taha,2007)
Figure iv shows the pattern for the EOQ, this describes the depletion of stock and re-ordering
of production materials. t0 is the ordering cycle, y is the order size and D represents the
demand.
Cost Model of Multi-item Economic Order Quantity (EOQ) with storage limitation
The mathematical model best describing the case study is the inventory control in a store
system with multiple items and a constraint on the overall storage area or volume. The
algorithm computes optimal values of the inventory control parameters for each item such
that to minimize the cost function:
190
∑(
)
subject to the constraint that,
∑
Output data of the algorithm are:
- optimal quantity of an order for the i-th item
, i = 1, 2, …, n;
- optimal time of an operating cycle for the i-th item i = 1, 2, …, n;
- optimal reorder point for the i-th item
, i = 1, 2, …, n;
- optimal average annual costs in the system .
Algorithm
The algorithm used in the development of the software is stated below in the following steps:
Step 1: Start
Step 2: List the production materials
Step 3: Provide minimum and maximum allowable stock values
Step 4: Specify the rate and ratio of usage for production
Step 5: Specify the machine working rate
Step 6: Calculate the production rate
Step 7: Check the lead time(delivery time)
Step 8: Calculate the amount of raw materials to use
Step 9: Check if the inventory will be sufficient for production
Step 10: Stop
191
Result and Discussion
Figure v: The System Architecture
The system architecture shown above in Figure v is the overview and the interactions
between the various components of the developed manufacturing system.
Figure vi: The user interface
The figure above is an excerpt from the developed software. This is the main interface that
serves as link to other interfaces of the software. From this interface, the user can select from
the listed options what he wants to do. Since inventory management is mostly about knowing
192
the amount of raw materials, Work-in-progress, finished goods, knowing the optimal time to
order and the optimal quantity to order, these capabilities have all been embedded in the
software composition. When the user clicks on his intention, the interfaces that will be shown
have all been made user-friendly which enables the user to conveniently use the software.
Table i: Comparison of the relative costs of the manual inventory management and the
inventory management using the software developed for the case study
The results show that the cost incurred on manual inventory management of the
manufacturing firm can be reduced to a high extent. From table i above, the cost of inventory
management for each year reduced at a high extent when the computerized inventory
management is employed. Depending on the production size, the sum of production cost in
the fiscal year 2007 which was ₦ 627, 000 compared with the cost of production in 2008, ₦
51,000 shows the dependability of production cost incurred on the size of production.
However, it should be noted that, regardless of production, cost is always incurred on
inventory keeping, which is called Holding cost.
Two statistical analysis were carried out, one to test for chance (Correlation) and the other to
test for the difference in mean costs (difference of two means). Using a confidence level of
99% (significance level of 0.01), the null hypothesis were both rejected, affirming the
betterment of computerized system over the manual inventory system.
Conclusion and Recommendation
The overall objective of inventory control is to maintain stock levels so that the three main
costs, Holding cost, Ordering cost and Stock-out costs are at a minimum. Lucey (1984). The
two main considerations to ensure this is to determine when to order and how much to order.
The results gotten from the application of the software “manInvent” developed during this
research work clearly shows that the use of computer programmed software in inventory
management is the best tool for achieving these objectives. The validation of the software at
the case study was observed to ensure better working environment, reduction in task time due
to counting, calculation and other mathematical tasks during file keeping, and also ensures
high work efficiency, productivity and forecasting production requirements.
Based on the results obtained and conclusions drawn, it is recommended that the procedures
adopted in the software “manInvent” be used in inventory management in the manufacturing
sector of the country as this will enhance productivity and thus leading to technological
advancements in the nation and also competitiveness in the manufacturing world. The
software is also recommended that the software be extended to the medium and small scale
manufacturing industries as this will bring about reduction in costs accrued in manual
inventory management and also increase productivity since forecasting is easily done. The
software is also strongly recommended for the merchandizing industries, since almost the
same algorithm are used for both the manufacturing and the merchandizing industries.
Years 2007 2008 2009 2010 2011
Computerized
Inventory Management(₦)
479000 18000 12750 11950 9500
Manual Inventory
Management(₦)
627000 51000 89000 37000 21000
193
Acknowledgements
The correspondence author would like to acknowledge the assistance of the production
manager and the staffs of the case study industry, Intermarkets Nigeria Limited, Osogbo,
Osun State, Nigeria for their ample help and information supply towards the development of
the software, ‘manInvent’.
REFERENCES
[1] Adejuyigbe, S. B (2002). CAD/CAM for manufacturing. Topfun Publications, Akure,
Nigeria. Pgs. 65-69.
[2] Brown Steve, Kate Blackman, Paul Cousins and Harvey Mayor, (2001) Operations
Management: Policy, Practice and Performance Improvement pp 211-230
[3] DeBaise, Colleen (2010). "Technology Basics for Business". The Wall Street Journal
Complete Small Business Guidebook.
[4] Fogarty, D. W., Blackstone, Jr, & Hoffmann, T. R. (1991). Production and Inventory
management. (chap. 3, 5, 6, 9, 17, 20). 92nd ed.). Southwestern publishing
[5] Gerardo, Molinary Fernandez (2000). The evolution of inventory management in
Manufacturing and services Companies, Centro de Investigaciones Comerciales e Iniciativas
Academicas de la Facultad de Administration de Empresas. Forum Empresarial. Vol.5 Num2
[6] Kalpakjian, Serope and Schmid, Steven R (2006). Manufacturing, Engineering and
Technology, Pearson Education Inc, Upper Saddle River, NJ
[7] Lesonsky, Rieva (1998). "Tracking Inventory". Entrepreneur Magazine.
[8] Miller, D.E (1997). The Logistics of Low Inventories. APICS: the performance Advantage
Mayor (pp. 56-58)
[9] Omolehinwa, E. O (1985). Fundamentals of Cost Accounting. Lagos
[10] Scholasticus, K. (May 26, 2010). "Inventory Management Techniques". Buzzle.com.
http://www.buzzle.com/articles/inventory-management-techniques.html.
[11] Taha, Hamdy A (2007). Operations research: An Introduction 8th ed., Upper Saddle River,
New Jersey, Chap. 11, 14
[12] Terry Lucey (1984). Quantitative Techniques. 2nd
ed. D. P Publications Ltd, Hampshire,
Chap.4, 16
[13] Wagner, H.M. and Whitin,T.H (1958). “Dynamic Version of the Economic Lot size Model,”
Management Science, Vol. 5, pp.89-96
194
e-Diabetic Dietary System for the Rural Community
1Nyathi T.,
2Dube S. and
3Sibanda K.
1,2,3National University of Science and Technology, Department of Computer Science,
P.O Box AC939, Ascot, Bulawayo, Zimbabwe.
Phone +263 9 282842 [email protected]
[email protected] and [email protected]
Keywords: Diabetes, e-Diabetic, Diabetic diet, mhealth
Abstract
A healthy balanced diet is important to someone living with the condition of diabetes.
Diabetes is a condition where the body fails to regulate blood sugar levels due to the
malfunctioning of the pancreases where it fails to produce sufficient insulin. This leads to the
two types of diabetic conditions type 1 and type 2. Type 1 is attributed to a faulty immune
system and is usually hereditary, while type 2 is a complication which arises as a result of an
unhealthy diet and lifestyle. According to population distribution statistics in Zimbabwe, the
majority of the population resides in the rural areas. Poverty rates are high in rural areas.
Zimbabwe has the highest literacy rate in Africa 92% and yet despite that the affliction of
diabetes is still attributed to witchcraft implying that there is not enough relevant information
about diabetes being disseminated. It is a condition which has no traditional herbal remedy.
Diabetes is a condition which can be managed through diet and medication. However in the
rural areas there is a major challenge of proper dietary information being available. The
most common flow of information in the rural areas is through radios and newspapers which
are usually outdated. Rural electrification is still an ongoing process and the rural populace
have managed to improvise their power requirements through the use of solar panels.
Currently the most popular mode of communication to people in the rural areas is through
mobile phones where mobile penetration is also high and where people are able to
conveniently recharge their mobile phones through solar power. This paper presents a
plausible platform proposal for the dissemination of dietary information to people living with
the diabetic condition in the rural areas. The system is based on the Global System for
Mobile (GSM) communication and will utilize the short message service (SMS). The system
will broadcast information specific of available foods and indigenous fruits available within
that region.
1.0 Introduction
Once an individual is diagnosed with a chronic ailment, it is imperative that they have access
to adequate information pertaining to the management of that ailment. In this regard a person
suffering diabetes is no exception. The Acquired Immune Deficiency Syndrome (AIDS) has
taken center stage in the health care circles. This is mainly due to the fact that the virus is
contagious while conditions like diabetes are largely hereditary and non epidemic. As a result
most awareness funding has been directed towards HIV/AIDS [1]. The biggest threat to an
individual suffering from the condition of diabetics is the sugar content of the food they eat
[2]. It is of great importance for a diabetic to be able to manage the food they intake in order
to balance their blood sugar levels. In an ideal society there should be information centers
which disperse the required information of how to live with the condition of diabetes.
Currently within Zimbabwe the only information resources regarding diabetes are found at
private surgeries. For one to be able to get this information you need to consult a specialist or
nutritionist which are few and far in between are located in the city centres. The majority of
the Zimbabwean population reside in the rural areas. The rural population has syncretic
195
religious practises which has a heavy reliance on spiritual faith. There is no known traditional
remedy or control of the diabetic condition although some herbs do help in relieving some
symptomatic diseases caused by unbalanced sugar levels. In the rural areas before scientific
medical help is sought there is a myth that conditions like diabetes are caused by acts of
witchcraft. Usually people attend provincial clinics after consulting local herbalists who will
have failed to mitigate the symptoms. When dealing with chronic conditions like diabetes
time is of the essence with regard to diagnosis and control.
The use of Information Technology (IT) in various aspects of human life has expedited the
process of globalization. Mobile phones in particular, have contributed tremendously towards
this globalization due to their portability. Latest statistics from Technology Zimbabwe
indicate ‘mobile phone penetration in Zimbabwe of 80 % from a population of 12.5 million
[3].’ The mobile phone has proved to be one of the most influential pieces of technology
developed in modern science. Zimbabwean rural communities have not been left out in this
proliferation of the mobile phone aided by the advancements in solar power technology [4].
Almost every rural household has solar power to provide power to drive their portable radios
and charge their mobile phones. As a vehicle of communication media the success of the
short message service (SMS) has very few parallels. It takes advantage of two elements, price
and speed which is what it owes to its success. For a rural population an SMS system is an
ideal interactive mode of communication considering the lack of adequate finances. Diabetics
in rural areas have no platform or resource where they are able to request and receive
continuous awareness information regarding how they may achieve better living with their
condition.
In this paper we propose an information dissemination system for diabetics living in the rural
areas. With ICT now pervasively affecting all areas of social and economic life, several
opportunities arise where we can enhance areas of healthcare with the view of improving
rural community life [5]. The system will supply information regarding the dietary
recommendations and supplementary food with special emphasis on the location of the
individual.
2.0 ICT Technique of Disseminating Information to Rural Communities
There are several traditional methods and vehicles of information dissemination, both formal
and informal. Currently the information on diet for people living with diabetes is too
centralised and not structured. Posters and pamphlets are found in central hospitals in the city.
To date besides a direct phone call the only form of ICT infrastructure being utilised to
distribute information to rural communities is radio and television.
Radio and Television
Government and Non–Governmental Organisation (NGO) sponsor adverts
and awareness programs on radio and television for the benefit of those living
with diabetes. These are however broadcast programs where the diabetic or
interested party is unable to ask specific questions regarding their affliction.
The information disseminated through these platforms is general and does not consider the
individual. Budgetary constraints of people with the diabetes condition are usually not
considered as well.
3.0 Related Systems
Several SMS based systems have been developed for use in other sectors of ICT. The
popularity of SMS based systems is mainly due to the reliability SMS technology. The rural
population is adequately equipped with the required ICT facilities specifically mobile phones
196
[5]. [6] is a phone based information portal that enables interactions through voice.
Information can be accessed by dialling the phone number and the response listened to rather
than reading it. This system [7] has challenges of high cost, not being real time and non
specific. A recent study in Tanzania called SMS for life demonstrated that SMS technology
can be easily to improve information distribution to health related areas in rural life [8].
Botswana has several mHealth systems under test in rural areas [9]. These systems focus on
assisting rural medical practitioners with consultations, education and capacity building. The
practitioners buffer the patients and the patients are unable to interact with the systems
directly. South Africa [10] runs a Cell-Life project backed by Vodacom where healthcare
professionals monitor HIV treatment administered to their patients using mobile phones.
4.0 Proposed Platform
This paper proposes an innovative architecture to be developed that provides a solution to the
problems faced by rural diabetics. We aim to develop a system that utilises and integrates the
existing GSM technology. The choice of SMS is based on reliability, availability and
economic reasons. The functionality of the system will require a user to send a SMS to a
short code number issued by a mobile service provider which results in the enquiry being
delivered to the backend of the system. The system may be probed for several types of
information with respect to diabetes, such as general dietary information, specific dietary
information, recommended intake quantities of specific foods and location specific
supplementary foods available regarding diabetes. In order to aid the attribute of usability
user registration will not be compulsory with this system.
4.1 Methodology and Design.
An iterative design and development methodology will be used in developing this
system. A case study rural area will be chosen such that the user requirements of
diabetics are well captured in order to address their needs accurately. Zimbabwe has a
Zimbabwe Diabetic Association and it is envisaged that this system will be housed by
that association. However a nutritionist is required to analyse data collected from rural
areas regarding locally available foods and indigenous fruits which are required to be
populated on the knowledge base.
Figure I Conceptual Deployment Model
197
RC1 – Rural Community 1
Figure 1 is an illustration of the conceptual deployment model where the system‘s
data is sectionalised into rural communities. Each rural community is independent
from the other and they are linked to the Server via the GSM network. The data
specific to a certain community has to be populated prior to use.
Figure II Data Flow Diagram
Figure II is the data flow diagram if an enquiry is location related the system has to
verify the location.
Message Formats
Depending on the numbers of potential users involved the dietary database
information can be connected to the GSM network directly to the SMS center (SMSC)
if there is a large number of users or via a SMS modem gateway for a minimal
number of users. User education is necessary in order for the proper structures of
messages to be accepted by the system. The appropriate structure of the message will
be designed once the understanding of the user has been gauged.
Diet Formats
Dietary information will be stored in two formats in the data store, a) string format
and b) templates. Templates are a restriction brought about because of the limitation
of the number of characters possible with an SMS. For accurate diet template retrieval
the server application will make use of a pattern matching neural network as the
foundation of information retrieval.
198
Receive SMS
Validate
SMS Format
Reply SMS RQST
Resend
Retrieve Diet
Information
Format SMS into
Search String
Reply SMS
Figure III. SMS Flow Chart
The diagram above captures the flow of the SMS once it arrives at the server.
4.2 System Architecture
Figure IV Proposed Overall System Architecture
5.0 Limitations The information disseminated by this system is at best a recommendation and not cast in
stone. Individuals are different and are affected differently by different foods, it is therefore
important that the necessary specialist i.e. nutritionists be the ones to administer this system
for ethical reasons. The system is designed to have a recommendation of indigenous fruits.
This introduces language barriers particularly in names of indigenous fruits as the English
199
names of such fruits are not common in ordinary day to day vocabulary of villagers.
Technically the size of the number of characters capable via SMS imposes a restriction.
6.0 Discussion
According to the Zimbabwe Diabetics Association close to 50% of Zimbabweans are living
with diabetes [1]. With the majority of the population resident in the rural areas it stands to
reason that the proposed system would provide an ideal platform for disseminating diabetic
related information particularly to the too often neglected rural populace. The challenges
facing rural communities are similar particularly in sub- Saharan Africa. These include
poverty, minimal availability of basic human needs, low levels of formal education, and
inadequate infrastructural developments of water, electricity and telecommunications. This
proposed system should be able to connect diabetic patients in resource poor areas with
appropriate information. It provides a reliable method for information dissemination and
provides an appropriate platform to collect reliable data that can be analysed and filtered.
Finally if deployed appropriately this system should provide a method to improve the quality
of life of those afflicted with diabetes living in rural areas.
References
[1] Biriwasha MKC (2009). Diabetes in Zimbabwe Its not All About Sugar.
www.modernghana.com/news/diabetes-in-zimbabwe. Accessed 30 June 2012
[2] LaCapria K (2012). Diabetes a Growing Threat with No Single Dietary Answer
www.inquistr.com Accessed 30 June 2012
[3] Kabweza L.S.M (2012). Telecel hits 2 million subscribers. Zimbabwe’s mobile
penetration now 80%, http://www.techzim.co.zw/ Accessed 12 July 2012
[4] Econet (2012). Solar Products to Enrich your Life. www.econetsolar.com Accessed
18 July 2012
[5] Bekiaris E, Panou M & Kalogirou K (2012). Mobile Applications for the Elderly
with Disabilities. In Proceedings of the International Conference IST-Africa.
[6] Agarwal S.K, Kumar A, Nanavati A.A & Rajput N (n.d) Content creation and
dissemination by and for users in rural areas. www.researchintouse.com/resources
Accessed 13 July 2012
[7] Mwakaje A.G (2010). Information and communication Technology for rural farmers
market access in Tanzania journal of information Technology Impact 10 (2) 111-128
[8] Barrington J, Wereko-Brobby O and Ziegler R (2010). SMS for life: Tanzania Pilot
Project Report. http://www.corporatecitizenship.norvatis.com/patients/access-
medicines/access-in-practise/SMS-for-life.shtml Accessed 10 July 2012
[9] Littman-quinn R, Chandra A, Schwart A, Chang AY, Digovich K and Kovarik C ,
(2011). mHealth Applications for Clinical Education, Decision Making and Patient
Adherence in Botswana. In Proceedings of the International Conference IST-Africa.
[10] Cell-Life, (2012). www.cell-life.org Accessed 20 July 2012
[11] DiabetesVoice, (2011). www.idf.org/zimbabwe-diabetic-association Accessed 1 July
2012
200
GREEN ECONOMYAND INNOVATION: COMPRESSIVE STRENGTH
POTENTIAL OF BLENDED CEMENT CASSAVA PEELS ASH (CPA)
LATERIZED CONCRETE (LATCON) Agbenyeku, E.E.
1) Okonta, F.N.
2)
1) 2) Department of Civil Engineering Science, Faculty of Engineering and the Built Environment,
University of Johannesburg, South Africa 1) E-mail: [email protected]
Key words: Laterite (Lat.), Laterized Concrete (LATCON), Cassava Peels Ash (CPA),
Compressive Strength (N/mm2), Agricultural Waste
Abstract
This work highlights the incorporation of two locally available materials; Cassava Peels Ash
(CPA) and Laterite in concrete production for construction purposes. The abundance of these
materials in West-Africa paved way for this study. The effect of partial substitution of cement
with an agricultural waste; CPA on the compressive strength of Laterized concrete (LATCON)
was investigated. Results of the physical and chemical tests on CPA and Laterite, revealed them
to have satisfactory characteristic properties for concrete production. A total of 192 cubic
specimens of 100mm dimensions were cast and cured by complete submergence in water for 7,
14, 21 and 28-days hydration period, adopting a 28-day targeted strength of 25N/mm2 as
control. The cement/CPA and sand/laterite replacements ratios ranged from 0 to 30%, with a
view to determining the best compositions matrix. The density and compressive strength
performance decreased with increase in the CPA and laterite content. However, a gradual
strength development in the CPA-LATCON was observed as the hydration period increased.
Hence, the 28-days density and compressive strength of the normal concrete was 2385(Kg/m3)
and 27.05(N/mm2) while the 10%CPA+10%Laterite sample (i.e. best replacements matrix) had
2322(Kg/m3) and 25.57(N/mm
2) respectively. The strength of the CPA-LATCON (25.57N/mm
2)
was higher than the adopted strength of (25N/mm2) at the 28day, which makes it suitable as a
building material. As such, it can be adopted in the construction of simple foundations and
masonry units as reliable alternatives to the scarce and expensive conventional materials for
prime cost reduction in rural housing and development without compromising standards.
INTRODUCTION
From economic stand point, the high inadequacies in housing delivery have mainly been due
to an excessive and persistent rise in the cost of conventional building materials especially
cement [1]. As such, research trends in the development of materials have strongly and
basically shown a global venture into out sourcing of alternatives driven by various
challenges such as; difficulty (ies) in accessing fund for building/construction developmental
projects, high cost and insufficiency (ies) of conventional materials, bio-degradability of the
materials, need for recycling agricultural waste materials for construction, the strive to
maintain population growth, remediation and preservation of ecological balance and the need
for shelter amongst other pressing needs [2-4]. It will therefore seem natural that the civil and
building engineering industries be increasingly forced to consider the possibility (ies) of
utilizing the vast, unsightly and idle accumulation of waste materials left by industrial and
agricultural activities [5]. Efforts have been propelled toward the successful exploitation of
the efficient use of products such as; foundry waste, rice husk ash, corn cob ash, fly ash,
natural fibers, etc., that have being incessantly generated. In developing countries the
generation of supplementary cementitious materials (SCMs) is said to be fundamental to
achieving and advancing low-cost construction materials to be used in the production of self-
201
sufficient means of shelter. Apart from improving concrete properties, the main benefits of
SCMs include saving natural resources and energy as well as protecting the environment
through the use of these main admixtures.
Utilization of laterite as a partial substitute for fine aggregate in concrete production for
building purposes have been studied and carried out as attempts to necessitate the local use of
available materials littering our construction sites and surroundings as waste products [6].
The reuse of waste products will help to keep our surroundings from environmental
degradation, pollution and severe ecological distortions. Consequently, alternative source for
the potential replacement of fine aggregates in concrete has gained consideration. Reasonable
studies have been conducted to find the suitability of laterite as substitute for sand in
conventional concrete and the use of waste ash to replace cement [7-10]. Small amounts of
inert fillers are acceptable as cement replacement. If the fillers have pozzolanic properties,
they convey not only technical advantages to the resulting concrete but also enable larger
quantities of cement substitution to be achieved [11]. Amorphous silica present in the
pozzolanic materials combines with lime and forms cementitious materials. These materials
can improve the durability of concrete, the rate of gain in strength and can also reduce the
rate of liberation of heat of hydration which is highly advantageous for mass concrete.
Over recent decades, Portland cements (PCs) containing Fly Ash (FA) and silica fume have
gained increasing acceptance while PC containing artificial pozzolans like rice husk ash and
burnt oil shale are commonly used in regions where they abound. Efforts are also being
channeled toward substituting cement (wholly or partially) with locally available pozzolanic
materials like volcanic ash, rice husk ash, saw dust ash, millet husk ash, pulverized fuel ash,
bagasse (sugar cane) ash and others in concrete [12,13].
Laterite has been identified as a possible material for partial replacement of sand in concrete
to produce what has been called laterized concrete (LATCON), while studies have been
carried out on effects of laterite incorporation in strength and serviceability properties of fresh
and hardened concrete [14−19]. The 28-day strength is used as a trial assessment of
pozzolanic activity in accordance to ASTM C618 [20]. This paper investigates the effect of
the incorporation of the locally available laterite soils on strength characteristics of concrete
with the addition of another locally available pozzolanic material (CPA) as partial
replacement for cement [21]. The addition of cassava peels ash (a seemingly agricultural
waste and supposed potential cyanogenic material), into concrete is viewed as an attempt to
transform an agricultural waste material to an affordable and useful end product.
REVIEW OF RELATED LITERATURE
Recent research trends on in and out sourcing, discoveries, development and the use of
alternative, non-conventional materials have been concentrated either on purely partial or
total replacements of cement in concrete on one hand and the substitution of sand with laterite
on the other hand. According to Job [22] efforts have been invested by researchers like
Talero [23], Smith [24], Popovics [25], and Neville [26] to practically substitute cement with
locally available materials called pozzolanas. “Pozzolana” is used to describe naturally
occurring and artificially siliceous or siliceous and aluminous materials, which in themselves
possess little or no cementitious value but will, in finely divided form and in presence of
moisture, chemically react with calcium hydroxide at ordinary temperatures to form
compound possessing cementitious properties [27-30]. In various parts of the world, it has
been revealed by researchers that pozzolanas can produce concrete with close characteristics
as normal concrete at age 28-days and beyond. Application of various ashes as potential
cement substitutes and replacements in mortar and concrete production has attracted the
attention of researchers because of its tendencies to: (I) reduce the quantity and consequently
the costs of cement applied in concrete works, and (II) reduce or eliminate the classification
202
of ashes as waste materials polluting the environment. In recent times, experimental studies
by researchers have been encaged on variety of waste ashes and materials with pozzolanic
potentials such as rice husk ash, saw dust ash, wheat ash, sugar cane fiber (bagasse) ash,
pulverized fuel ash, volcanic ash, groundnut husk ash, blast furnace slag, and mining tailings
[12,23].
Cassava which is an extensively cultivated annual tuberous crop (See Figure-2) provides a
basic diet for well over 500 million people and is the third largest source of food in the
tropical and sub-tropical regions. According to FMINO [31], incinerated CPA is a by-product
of the combustion of the massive agricultural refuse generated from cassava processing. It is
grown in all ecological zones of Nigeria, but most predominantly in the middle belt and the
southern parts of the country. It is rich in mineral constituents such as; carbohydrates, starch,
protein, fats, and fiber etc., which makes it a very good food and highly reliable source of
energy, sweeteners and industrial raw material.
Laterite on the other hand, covers about one third of the earth’s continental land area,
extensively covering areas in tropical countries with Africa being one out of the six main
regions of the world where laterite is found. LATCON has over time, attracted the attention
of many authors and researchers. The word “LATERITIC” possess different meanings among
researchers. Hence, various definitions have been suggested based on its chemical,
morphological and physical properties. Fermor [33] defined various form of lateritic soils on
the basis of the relative contents of laterite constituents (Fe, Al, Ti, Mn) in relation to silica.
Based on its morphological properties, Pendelton [34] defined lateritic soils as a profile in
which immature laterite horizons become true laterite strata if appropriate conditions prevail.
As regard to the physical properties, lateritic soils have been defined as an igneous rock,
tropically weathered in-situ, which has decomposed partially or totally with the concentration
of Iron and Aluminum Sesquioxides (combined Fe2O3 and Al2O3). Gidigasu [32] as cited in
Olusola [19] defined laterite as a term used to describe all the reddish residual and non-
residual tropically weathered soils (see Figure-6), which generally form a chain of materials
ranging from decomposed rock through clay to sesquioxide (Al2O3+Fe2O3).
Laterite, either in raw form or improved form is commonly used both in rural and urban areas
for housing construction in forms of masonry units. They are utilized in Nigeria, in a fashion
of hydra-forms (i.e. interlocking stabilized laterite) blocks, basically used for low-cost
housing schemes in some states (e.g. Lagos, Ekiti, Kebbi, e.t.c.). LATCON according to
Olusola [19] refers to concrete in which the fine aggregate (sand) has been totally or partly
replaced with laterite; total replacement is referred to as terracrete. An argument by Neville
[29] reported that a total replacement of sand with laterite in concrete production can rarely
be stronger than 10 MPa (10 N/mm2) while studies by Ata [18], Olusola [19] and Osunade
[35] have proven that laterite can produce concrete of much higher grades. The uncertainties
around the use of laterite as a construction material are enormous. Knowledge of its physical
properties, strength characteristics and reliability before use are a major challenge and so is
the knowledge of the actual performance of structures made from it under varying climatic
conditions and difficulties of quality control [3, 36]. As such, it has not been widely utilized
to an equal level as sandcrete blocks and normal concrete, especially for works with structural
emphasis [3]. Investigations have revealed that stabilized laterite (i.e. laterite mixed with a
certain quantity of cement ≤ 10% by weight) can be beneficially used for the production of
masonry units and that laterite holds potency as a partial substitute for sand in concrete
works, both for structural and non-structural purposes. Although, the general public believes
that for laterite to be used on a wider range, it should be properly investigated and improved
at the technical level.
203
MATERIALS AND METHODS
Cassava peels utilized in this study as shown in Figure-3, were collected as refuse from a local
processing factory in Ikot Ekepene, Akwa Ibom State of Nigeria where at present, a wide range
of traditional cassava meal forms (such as gari, fufu, starch, lafun, abacha, etc.) are produced
for human consumption. The peels were dried in open air, burnt to ash and eventually
calcinated up to 700oC in an electric furnace. The resulting highly reactive amorphous clinker
was grinded into fine powdery form and passed through the 75μm sieve (see Figures-4 and 5).
Elemental test results in Table-1 on Laterite and CPA done by X-Ray diffraction (XRD), X-
Ray fluorescent (XRF), Atomic Absorption Spectrometer (AAS) and Colorimeter Analysis,
show that the total content of Silicon Dioxide (SiO2), Aluminium Oxide (Al2O3) and Iron
Oxide (Fe2O3) in CPA is (71.24%) which is slightly above the minimum of 70% specified in
ASTM C618 [20] as such, qualifies it for use as pozzolana. Laterite was found to possess a
Silica Ratio (SR) of 0.52. The Silica: Sesquioxide (S-S) (SiO2/Al2O3+Fe2O3) ratio was less
than 1.33 indicating a true laterite classification as per Fermor [33].
Table-1: Chemical composition of CPA and Laterite (%) Chemical Content
Fe2O3 SiO2 Al2O3 CaO
MgO
TiO
LOI
SiO2+Al2O3+Fe
2O3 Sesquioxide SiO2/Al2O3
+Fe2O3
CPA 4.95 61.8 4.49 5.42 6.14 - 1.45 71.24 - Laterite 34.2 28.9 21.7 - - 1.26 - - 0.52
Respective mixes with four levels of CPA and Laterite replacements, each ranging from 0 to
30% (i.e. a total of 16 levels of samples produced in triplicates) were investigated. The control
specimen was proportioned for a targeted strength of 25N/mm2 in line with the British Mix
Design (D.O.E) method been the required minimum strength for structural concrete in
accordance to BS8110. It had a cementitious material content of 306 Kg/m3, fine aggregate
content of 620 Kg/m3, coarse aggregate content of 1235 Kg/m
3 and a water cementitious
materials ratio of 0.65 giving a free water content of 190 kg/m3. The cement/CPA and
sand/laterite substitutions were computed by weight. From Table-2, physical properties from
preliminary test results of the constituent materials, shows the specific gravity of the CPA to be
(3.07) which is clearly less than that of cement (3.15) as per Neville [29]. The fine aggregate
used were sand and laterite. The laterite was collected from an excavated trench in Aba North,
Abia State Polytechnic, Aba, Nigeria. While the sharp river sand, free from impurities and
injurious substances was obtained from Ogbo hill, Aba South; the coarse aggregate was
obtained from “Rich Constructions Nigeria Limited, Aba” with specific maximum size 19 mm
(3/4 in). Portable tap water was used for the concrete mixing and curing processes. All the
aggregates conformed to the British Standard Specification [38] and the particle size
distribution for laterite is shown in Figure-1. “Burham”, locally produced ASTM Type I
Portland cement, conforming to the BS EN 197[37] was purchased from the open market and
used in this study.
Table-2: Summary of Physical Properties of Constituent Materials Parameters CPA Sand Laterite Granite
Specific Gravity 3.07 2.65 2.60 2.67 Bulk Density (Kg/m3) Uncompacted 1402 1398 1306 1359 Compacted 1628 1446 1359 1315 Void (%) 17.86 10.01 8.89 27.54 Moisture Content (%) 3.71 16.05 Sieve Analysis Fineness Modulus (m2/Kg) 2.45 2.87 Coefficient of Uniformity (Cu) 8.02 8.54 1.44 Coefficient of Gradation (Cg) 1.02 1.25 0.91
204
Series of tests were performed to investigate the effect of various percentage replacements of
CPA and laterite on the compressive strength properties (N/mm2) and demoulding densities
(Kg/m3) of both the fresh and hardened CPA/OPC LATCON. For the comprehensive strength
(N/mm2) to be gotten, a total of 192 (100mm) dimension cubic specimens were cast and
cured in water at room temperature for 7, 14, 21, and 28 days. At the end of every curing age,
three specimens of each mixture were tested by crushing them under direct loading using the
compression test machine and their averages were taken. Samples of CPA/OPC LATCON are
shown in Figure-7.
Figure-1. Grain size distribution curve for laterite soil sample
Figure-2. Harvested Cassava tubers Figure-3. Cassava Peels dump
Figure-4. Cassava Clinker Figure-5. Incinerated CPA Figure-6. Laterite Soil
Figure-7. CPA/OPC LATCON Specimens
0
20
40
60
80
100
0.075 0.15 0.3 0.6 1.18 2.36 4.75
PE
RC
EN
TA
GE
PA
SS
ING
(%
)
PARTICLE SIZE (mm)
PERCENTAGE PASSING (%) AGAINST PARTICLE SIZE (mm)
Laterite distribution
Curve
205
Table-3: Density (Kg/m3) and Compressive Strength (CS-N/mm
2) of CPA/OPC
LATCON
Hydration Periods
LAT CPA (%) (%)
7 14 21 28
Density CS Density CS Density CS Density CS
0 0 2435 11.24 2448 16.52 2453 23.98 2385 27.05 10 2350 9.46 2369 13.23 2351 19.32 2332 24.41 20 2317 7.87 2329 11.24 2321 15.31 2315 19.98 30 2289 7.78 2292 9.34 2287 13.27 2282 17.62
10 0 2346 8.32 2365 12.52 2362 16.13 2371 21.90 10 2323 7.44 2337 9.58 2332 14.35 2322 25.57 20 2323 7.39 2309 8.87 2294 13.59 2291 22.01 30 2291 5.97 2282 6.88 2264 11.52 2286 17.97
20 0 2364 8.34 2368 9.86 2341 13.51 2338 18.77 10 2339 6.87 2346 8.54 2333 12.41 2277 16.98 20 2309 5.57 2327 6.82 2334 11.67 2315 16.64 30 2262 4.45 2284 5.97 2257 9.86 2259 16.05
30 0 2328 7.29 2347 9.64 2359 12.85 2339 18.01 10 2316 6.65 2319 7.86 2324 11.58 2312 16.64 20 2275 5.12 2291 6.26 2288 10.22 2282 14.44 30 2260 4.74 2271 5.87 2257 8.98 2253 11.97
RESULTS AND DISCUSSION Values of the density (Kg/m
3) and compressive strength (N/mm
2) for the investigated
concrete samples are shown in Table-3. Figure-8 shows the strength comparison between the
control sample and equal replacement matrices.
Figure-8. Compressive Strength (N/mm2) for equal replacement matrix (%)
The results reveal a high Coefficient of determination (R2 values), indicating a direct
relationship and strong correlation between the strength gain and the curing ages (i.e. an
increase in hydration period leads to an increase in strength). The strengths for
0%LAT+0%CPA replacements (i.e. the control specimen) and 10%LAT+10%CPA
replacements (i.e. the best replacement matrix) at age 28-days, were gotten as 27.05(N/mm2)
and 25.57(N/mm2) respectively. There is high tendency for these LATCON samples to attain
strength values similar to the control sample at later periods, since strength of cement blended
with pozzolanas normally improves with age. However, the trend shows a gradual strength
development of the CPA/OPC LATCON as the hydration period increases.
0
5
10
15
20
25
30
7 14 21 28
CO
MP
RE
SS
IVE
ST
RE
NG
TH
(N
/mm
2)
HYDRATION PERIOD (days)
COMPRESSIVE STRENGTH (N/mm2) AGAINST HYDRATION
PERIOD (days)
0%Lat+0%CPA R² = 0.978
10%Lat+10%CPA R² = 0.891
20%Lat+20%CPA R² = 0.940
30%Lat+30%CPA R² = 0.965
206
Figure-9. Effect of LAT+CPA replacements (%) on Concrete Density (Kg/m
3)
It can be seen from Figure-9; that the percentage increase in Laterite and CPA, led to a
decrease in the respective density of LATCON. The density of the control sample was 2385
Kg/m3 at the 28-day; while the 10:10% replacements density was 2322 Kg/m
3 indicating a
loss of about 2.6% accounted for as a result of the differences in the fineness modulus and
specific gravity of the CPA and Laterite as compared to cement and sand respectively.
Figure-10. Effect of LAT+CPA replacements (%) on Strength (N/mm2) of concrete
Figure-10 shows a strong correlation between the compressive strength of the samples and
the percentage LAT+CPA replacements. The progressive drop in the strength of samples with
increase in LAT+CPA over the different hydration periods can be attributed the excess
contents of silica and / or alumina from CPA and the Laterite not used up in the reaction.
Hence, the excess addition of LAT+CPA simply contributed to the drop in strength.
Although, in consonance with the requirements of ASTM C618 for 28-day strength, the
20:20% replacement is the limit to which both the cement and sand be replaced for quality
and economy.
2100
2200
2300
2400
2500
0 10 20 30
DE
MO
UL
DIN
G D
EN
SIT
Y
(Kg/m
3)
LAT+CPA REPLACEMENTS (%)
DENSITY OF CONCRETE SAMPLES (Kg/m3) AGAINST LAT+CPA
REPLACEMENTS (%)
7days R² = 0.885
14days R² = 0.888
21days R² = 0.871
28days R² = 0.929
0
5
10
15
20
25
30
0 10 20 30
CO
MP
RE
SS
IVE
ST
RE
NG
TH
(N/m
m2)
LAT+CPA REPLACEMENTS (%)
COMPRESSIVE STRENGTH (N/mm2) AGAINST LAT+CPA
REPLACEMENTS(%)
7days R² = 0.910
14days R² = 0.866
21days R² = 0.887
28days R² = 0.939
207
Figure-11. Density of Concrete samples (Kg/m3) with respect to Curing Ages (days)
The drop in concrete density with increase in curing age as revealed in Figure-11; shows a
weak correlation between the concrete density and the curing period. The drop in density can
be due to water absorption and subsequent loss in materials caused by the effect of curing.
However, the trend is not linear as the densities of specimens with 10-30%LAT+CPA
replacements are seen to improve then eventually drop after 14days hydration period. The
increased densities experienced by the specimens are associated with changes in the water
absorption potentials of the mixes.
CONCLUSION AND RECOMMENDATION
The results presented revealed that the 10%LAT+CPA replacements (i.e. the best
replacement matrix) had 28-day strength of (25.57N/mm2), although it is found to be
less than the control specimen (27.05N/mm2), it appears slightly higher than the
targeted strength (25N/mm2). Hence, satisfies the minimum strength for structural
concrete in accordance to BS8110;
The compressive strength of LATCON samples increases with increase in hydration
period;
Water absorption and simultaneous loss in materials results in the reduction of density
of samples although, increase in density was observed for specimens of 10-
30%LAT+CPA content at 14days hydration period which is associated with the water
absorption potentials of the mixes;
Significant drop in compressive strength of LATCON samples was noticed in
association with excess silica and alumina content that were not utilized in the
pozzolanic reaction;
The introduction of Cassava Peels Ash (CPA) presents a good tendency of pozzolanic
activity, the laterite content provided additional contents of silica and alumina as such;
this paper demonstrates how the use of appropriate technology can transform
abundantly available natural soil and cheap agricultural waste into a natural resource.
Hence, the CPA/OPC LATCON can be adopted in the construction of masonry units
and simple concrete composites. While further investigations be done for longer
hydration periods of up to 120 days to ascertain its pozzolanic tendencies.
2150
2200
2250
2300
2350
2400
2450
2500
7 14 21 28
DE
MO
UL
DIN
G D
EN
SIT
Y
(Kg/m
3)
HYDRATION PERIOD (days)
DENSITY OF CONCRETE SAMPLES (Kg/m3) AGAINST
HYDRATION PERIOD (days)
0%Lat+0%CPA R² = 0.362
10%Lat+10%CPA R² = 0.020
20%Lat+20%CPA R² = 0.081
30%Lat+30%CPA R² = 0.342
208
REFERENCES [1] Achuenu, E., (1999). Elemental Approach to the Evaluation and Ordering of Cost Over-
Run of Public Office Building Projects in Nigeria, PhD Thesis, University of Jos.
[2] Falade, F.A., (1999).Utilization of Bamboo as Reinforcement in Concrete for Low-cost
Housing, Unpublished PhD Thesis, Department of Civil Engineering, University of
Lagos, Akoka, Lagos.
[3] Olusola, K.O. and Adesanya, D.A., (2004). Public Acceptability and Evaluation of Local
Building Materials for Housing Construction in Nigeria, Journal of Property
Research and Construction, Vol.1, pp. 83-98.
[4] Anthonio, J.O., (2002). Housing for All by the Year 2015, A paper presented at 2002
Building Week Seminar of Ife Association of Building Students, Obafemi Awolowo
University, Ile- Ife, 23rd April.
[5] Fashola, O.O., (1997). Properties of medium workability concrete incorporating
incinerated refuse ash, Unpublished M.Sc Thesis, Department of Building, University of
Jos, pp. 2.
[6] Elinwa, A.U. and Mahmood, Y.A., (2002). Ash from Timber Waste as Cement
Replacement Material, Cement and Concrete Composites, V. 24, No. 2, pp. 219-222.
[7] Al-Ani, M. Hughes, B., (1989). Pulverized-fuel ash and its uses in concrete, Mag. Concr.
Res.41 (147) pp. 55–63.
[8] Swamy, R.N., (1986). Cement Replacement Materials, Concrete Technology and Design,
Surrey University Press, Great Britain.
[9] Berry, E.E. Malhotra, V.M., (1980). Fly ash for use in concrete - a critical review, J. of
ACI 77 (8), pp. 59–73.
[10] Bilodeau, A. and Malhotra, V.M., (2000). High volume fly ash system: concrete solution
for sustainable development, ACI Mater. J, 99 (1), pp. 41–48.
[11] Khandaker M. and Anwar Hossain “Blended cement using volcanic ash and pumice”.
[12] Matawal, D.S., (2005). Application of Ashes as Pozzolana in Mortar and Concrete
Production, 1st National Academy Conference, 31st August - 2nd September
[13] Ujene, A.O. and Achuenu, E., (2005). The Compressive Strength of Concrete Containing
Varying Proportions Selected Locally Sourced Aggregates in Nigeria, International
Journal of Environmental Issues, Vol.3, No.1, pp. 81-87.
[14] Adepegba, D., (1975). A Comparative Study of Normal Concrete with Concrete which
Contained Laterite Instead of Sand, Building Science, Vol.10, pp. 135-141.
[15] Balogun, L.A. and Adepegba, D., (1982). Effect of Varying Sand Content in Laterized
Concrete, International Journal of Cement Composites and Lightweight Concrete,
Vol.4, pp. 235–241.
[16] Lasisi, F. and Ogunjimi, B., (1984). Source and Mix Proportions as Factors in the
Characteristic Strength of Laterized Concrete, International Journal for Development
Technology, Vol.2, pp. 151-158.
[17] Falade, F., (1991). Behaviour of Laterized Concrete Beams under Moment and Shear, Ife
Journal of Technology, Vol.3, No 1, pp. 7-12.
[18] Ata, O., (2007). Effect of Varying Curing Age and Water /Cement Ratio on the Elastic
Properties of Laterized Concrete, Civil Engineering Dimension, Journal of Civil
Engineering Science and Application, Vol. 19, No. 2, pp. 85-89.
[19] Olusola, K.O., (2005). Factors Affecting Compressive Strength and Elastic Properties of
Laterized Concrete, Ph.D. Thesis, Department of Building, Obafemi Awolowo
University, Ile-Ife.
209
[20] American Society for Testing and Materials, Specification for Coal Fly Ash and Raw or
Calcined Natural Pozzolan for Use as a Mineral Admixture in Portland Cement
Concrete, ASTM C 618, 2008.
[21] Olawuyi, B.J., (2008). An Evaluation of the Performance Characteristics of
Volcanic−Ash/Ordinary Portland Cement Laterized Concrete, Ph.D Thesis,
Department of Building Obafemi Awolowo University, Ile-Ife.
[22] Job, O.F., (1998). The Relationship between the Strength and Non-Destructive
Parameters of Pulverized Burnt Clay Concrete, Journal of Environmental Sciences (JOES),
Vol. 1, No. 2, pp. 9 (57 -64).
[23] Popovics, S., (1998). What Do We Know about the Contribution of Fly Ash to the
Strength of Concrete, Proceedings of 2nd International Conference, ACI Special
Publication SP-91, Malhot. V.M. ed., Detroit. Mich, 1986, pp. 313 -332
[24] Smith, R., (1987) .Rice Husk Ash, Cement Progress in Development and Application
Report from India, Nepal and Pakistan.
[25] Talero, R., (1990). Qualitative Analysis of Natural Pozzolanas, Fly Ashes, and Blast
Furnace Slags by XRD, Journal of Materials in Civil Engineering 2(2), pp. 106-117.
[26] Neville, A.M., (1992). Lime and Other Alternative Cements, U.K. International
Technology Publication.
[27] Neville, A.M and Brooks J.J., (2002). Concrete Technology, 2nd
Edition, London,
Longman Publishers.
[28] Shetty, M.S., (2004). Concrete Technology – Theory and Practice, New Dhelhi, India, S.
Chand and Company Limited,
[29] Neville, A.M., (2006). Properties of Concrete, 4th Edition, copyright © 2000, Asia,
Person Education Pte. Ltd.
[30] Hassan, I.O., (2006). Strength Properties of Concrete obtained Using Volcanic Ash
Pozzolan as Partial Replacement of Cement, M.Sc. Thesis, Department of Building,
University of Jos.
[31] FMINO., (2005). “Obasanjo Reform-Cassava Initiative Federal Ministry of Information
and National Orientation, pp. 1-4.
[32] Gidigasu, M.D., (1976). Lateritic Soil Engineering, Elsevier Scientific Publishing
Company, New York.
[33] Fermor, L.L. (1981). “What is Laterite?”Geology Magazine, 5 (8) 453 – 462.
[34] Pendelton, R.L. and Sharasuvana, S. (1994). Analysis of Some Siamese Laterites, Soil
Science. 62, pp. 423-440
[35] Osunade, J.A., (2002). Effect of Replacement of Lateritic Soils with Granite Fines on the
Compressive and Tensile Strengths of Laterized Concrete, Building and
Environment, Vol. 37, pp. 491-496.
[36] Osunade, J.A., (1991). Studies on the Suitability of Laterized Concrete for Grain Storage
Silo, Ph.D. Thesis, Department of Agricultural Engineering, Obafemi Awolowo University,
Ile- Ife.
[37] British Standard Institution, Cement- Composition, Specifications and Conformity
Criteria for Common Cements, BS EN 197: Part 1, London.
[38] British Standard Institution, Method for Determination of Particle Size Distribution, BS
812: Part 103, 1985, London.