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Articles 271 - 300 of 317

Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

User Friendly Computer Software For Construction Projects Delay Analysis, Kamel Ahmed Salem El Sayed May 2006

User Friendly Computer Software For Construction Projects Delay Analysis, Kamel Ahmed Salem El Sayed

Archived Theses and Dissertations

Construction industry around the world is facing a huge revolution in terms of number of executed projects. Projects are no longer simple ones managed by few persons. Commercial buildings, high rise towers and bridges are being built everywhere. The majority of these projects are complex ones that face a lot of obstacles. Delays are one of the major obstacles that construction projects face and are very likely to occur. Generally, claims are the result of any delay in the construction progress. To be able to analyze the claim and assign the responsibility, the analyst has to perform a delay analysis. …


Degradation Of Waterfront Reinforced Concrete Structures At The Port Of Dar Es Salaam, I Sanga Jun 2005

Degradation Of Waterfront Reinforced Concrete Structures At The Port Of Dar Es Salaam, I Sanga

Tanzania Journal of Engineering and Technology (TJET)

The paper summarises the results of an investigation done on piers at the Dar es Salaam Port. The problem facing these structures and marine facilities is their exposure to aggressive environmental phenomena. The paper presents an investigation of the strength and corrosion of concrete seaport piers so as to determine degradation of the reinforced concrete waterfront structures in the port of Dar es Salaam. For instance the structures at a dhow quay terminal had been in use for about 100 years. The facility was in bad condition as the concrete had been badly damaged due to corrosion. Some of the …


Ceramic Properties Of Chimala Kaolin Clay, Leonard Akwilapo Jun 2005

Ceramic Properties Of Chimala Kaolin Clay, Leonard Akwilapo

Tanzania Journal of Engineering and Technology (TJET)

The physico-chemical properties of kaolinite clays occurring in abundance near Chimala were studied with a view of finding out their suitability in sanitary ware production. The viscosity of the clay was found to be within the range acceptable in industrial application (≤ 500 cp for 70% solids), enhancing its prospects for the manufacture of slip cast shapes with satisfactory properties. The chemical composition of the clay reveals a high content of Fe₂O₃, 1.48%, which is expected to affect the translucency and colour of the finished ware. However, such quantity would not have detrimental effects in the production of sanitary ware. …


Earth Building In Tanzania - Use Of Soil Stabilized Bricks And Blocks, A Mrema Jun 2005

Earth Building In Tanzania - Use Of Soil Stabilized Bricks And Blocks, A Mrema

Tanzania Journal of Engineering and Technology (TJET)

This paper presents experimental results of investigations done on the use of stabilized earth (soil) for the manufacture of bricks and blocks. The soil used was clayey sand of low plasticity. Two types of stabilizers were used to make stabilized bricks and these were cement and a combination of cement and lime. Different stabilizer proportions were employed. Results of tests carried on these bricks at 28 days indicate an optimum mix proportion of 7% cement if cement is used alone and an optimum mix proportion of 5% each if a combination of lime and cement is used as a stabilizer. …


Cement Oonded Wood Wool Board As A Building Material For Low Cost Housing, A Mrema Jun 2005

Cement Oonded Wood Wool Board As A Building Material For Low Cost Housing, A Mrema

Tanzania Journal of Engineering and Technology (TJET)

This paper gives results of a preliminary study on the properties of cement bonded wood-wool boards manufactured as composites by using wood-wool (excelsior) from podocarpus spp wood species and ordinary Portland cement. Two main parameters were varied during the investigation and these were the width of the wood-wool and the cement to wood-wool ratio. Results show that the optimum mix proportion is three parts of cement to two parts of wood-wool by weight and that a smaller excelsior width gives higher board strengths. The results from tests on flexural strength, compressive strength and tensile strength far exceeded the requirements of …


Low Cost Slab Manufactured From Masonry Slab Elements, John Makunza Jun 2005

Low Cost Slab Manufactured From Masonry Slab Elements, John Makunza

Tanzania Journal of Engineering and Technology (TJET)

The construction of bungalow houses requires sufficient space to accommodate all the requirements as per the client’s wish. The idea of low-rise or high rise buildings is very remote for most of the people due to the high costs of construction involved. Much of the said cost is due to the concrete floor slab as it consumes a bigger portion of concrete material when compared to beams and columns. In this paper, a study presented is on a new form of voided slab constructed from masonry slab elements that do not utilize formwork and consumes less concrete material. The slab …


An Analysis Of The Relationship Between Environmental Management And Environmental Compliance At Marine Corps Installations, Bevin J. Keen Mar 2005

An Analysis Of The Relationship Between Environmental Management And Environmental Compliance At Marine Corps Installations, Bevin J. Keen

Theses and Dissertations

Environmental compliance on military is challenging for a number of reasons, including the complexity of regulations, and the variety of operations which impact the environment. At times, public concerns and penalties stemming from environmental issues has infringed upon the United States Marine Corps' (USMC) ability to use all installation resources without restriction. This thesis examines which facets of environmental management are closely associated with high levels of compliance. Five variables of interest: Total Compliance, Total Management, Audit Management, Policy Management, and Training Management were isolated from 1998-2004 USMC environmental audit data, and subjected to statistical analysis. Through the examination of …


Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo Jun 2004

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.


Introduction Of Seismic Resistance Features In The Construction Of Buildings In Tanzania, I Rubaratuka Jun 2004

Introduction Of Seismic Resistance Features In The Construction Of Buildings In Tanzania, I Rubaratuka

Tanzania Journal of Engineering and Technology (TJET)

Available dara indicates that a greater part of Tanzania lies within a seismic region. to date most Of the buildings in the country have been designed and constructed without considering seismic loads. In addition no design codes have been developed to guide the seismic design for buildings and other related structures in Tanzania. This paper outlines the basic design concepts, which are useful during the design of seismic resistant buildings before the seismic design code is developed and adopted in Tanzania.


Importance Of Structural Fire Protection In Reinforced Concrete Buildings: A Case Study Of Ex-Nasaco Building In Dar Es Salaam, I Rubaratuka Jun 2004

Importance Of Structural Fire Protection In Reinforced Concrete Buildings: A Case Study Of Ex-Nasaco Building In Dar Es Salaam, I Rubaratuka

Tanzania Journal of Engineering and Technology (TJET)

Reinforced concrete is concrete that is internally reinforced with steel bars or mesh. This gives rhe malerial the compressive strength of concrete along wilh the tensile strength Of steel. Reinforced concrete does not perform well under fire conditions as it spalls and loses strength. Heating Causes a failure Of the bond between concrele and sleels bars and this results in reduction of strength of concrele. Strength of concrete decreases With increase in temperature and increase With time. In order to provide fire resistance to structural components/elements in buildings, it is important Io consider the type of aggregates to be used. …


Development Of A Multidisciplinary Engineering Foundation Spiral, Samuel Bogan Daniels, Bouzid Aliane, Jean Nocito-Gobel, Michael Collura Jun 2004

Development Of A Multidisciplinary Engineering Foundation Spiral, Samuel Bogan Daniels, Bouzid Aliane, Jean Nocito-Gobel, Michael Collura

Engineering and Applied Science Education Faculty Publications

To operate effectively in today’s workforce engineers need to have a muti-disciplinary perspective along with substantial disciplinary depth. This broad perspective cannot be achieved by merely taking 2 or 3 engineering courses outside of the major, but rather will require a radical change in the way we educate engineers. The faculty of the School of Engineering and Applied Science at the University of New Haven have developed a new approach: the Multidisciplinary Engineering Foundation Spiral. This curricular model provides the needed mix of breadth and depth, along with the desired professional skills, by providing carefully crafted, well-coordinated curricular experiences in …


Developing A Methodology To Detect Partial Failures For Dynamic Systems, Anwar A. Al-Jowder Jan 2003

Developing A Methodology To Detect Partial Failures For Dynamic Systems, Anwar A. Al-Jowder

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research is to develop a decision support system that can assist in detecting partial failures in dynamic systems such as Fire Control System Tracking Radar (TR) onboard Naval Ships. Partial failures do not necessarily shut down the system immediately but cause degradation of operational performance. Previous work has shown that experts in the field of failure detection, test point insertion and Built-In-Test Equipment (BITE) can provide useful input in detecting partial failures. Partial failures affect operational system performance and support costs, which can be significant. Often, however, partial failure detection consists of the estimations and opinions …


Yucca Mountain Ventilation Studies Support And Associated Code Enhancements, George Danko Mar 2002

Yucca Mountain Ventilation Studies Support And Associated Code Enhancements, George Danko

Publications (YM)

The Task 20 project was prematurely closed by DOE on the basis of becoming critical data to the Yucca Mountain project. Task 20 indeed delivered the first, published hydrothermal-ventilation model, MULTIFLUX V1.0 and V1.1 to BSC during 2001 to support the AMR Rev01 report. The numerical model is designed to predict temperature and humidity distributions in and around the emplacement drifts and on the waste packages stored in a ventilated, high-level nuclear waste repository.


Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna Dec 1999

Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna

Tanzania Journal of Engineering and Technology (TJET)

Vibration is one of the techniques employed in the determination of dynamic properties of fruits and vegetables. It entails generation of a mechanical or acoustic vibrational signal which is propagated through the flesh of the agricultural material. A transducer is either attached or held close to the specimen to monitor the propagation of the signal through the specimen. The manner in which the signal is transmitted through the material is analyzed, and the dynamic properties of the specimen which relate to its firmness or its internal being are derived. The technique has been around for the past 30 years or …


Technical And Economic Comparison Of Performance Between Farmer And Government Managed Irrigation Schemes In Tanzania: A Case Study Of Kapunga Irrigation Project, D Chemka Dec 1998

Technical And Economic Comparison Of Performance Between Farmer And Government Managed Irrigation Schemes In Tanzania: A Case Study Of Kapunga Irrigation Project, D Chemka

Tanzania Journal of Engineering and Technology (TJET)

This paper conwares the perforinance Of governnyent ro fanner-managed irrigation schemes at Kapunga Rice Project in Mbeya Region, south-west Tanzania. The results showed that the farmer-managed irrigation scheme (FMIS) performed better than the government-managed irrigation scheme (GMIS) in attaining good performance. Applicable indicators for farmer-managed irrigation scheme are as shown below with those of government-managed scheme indicated in brackets. Its overall irrigation efficiency was 61' percent (29 percent) average productivity was 3.2 ton/liG (2.2 ton/ha); economic profirability: internal rate of return was 3.2 percent (5 percent), benefit/cost ratio of 0.60 (0.14); while its financial profitability: internal rate of return was …


Sustaina Bility Of Irrigation Schemes For Small-Scale Farmers: A Case Study Of Irrigation Scheme At Buleya Malima, Gwembe Valley, Zambia, Masinja R Jul 1998

Sustaina Bility Of Irrigation Schemes For Small-Scale Farmers: A Case Study Of Irrigation Scheme At Buleya Malima, Gwembe Valley, Zambia, Masinja R

Tanzania Journal of Engineering and Technology (TJET)

A study to determine facrors influencing sustainability of smallholder irrigation schemes was carried our a! Buleya Malima, Southern Province, 7_nnzbia. These factors included technical and socio-economic factors. found Out that the technical factors were 26.5, 64.5 and 9.2 percent for application efficiency, tailwater ratio and deep percolation, respectively, indicating that farmers wasted water mainly through tailwater runoff.From socio-economic point of view, the study indicated that the scheme lacked (i) farmer participation in designing and planning operation of the scheme (ii) managerial ability and innovativeness to form their own viable organisation: and (iii) formal training in technical operations of irrigation, infrastructure …


Experimental Study Of Rural Brick Burning In Iringa And Mbeya Regions, E Mushi Jun 1998

Experimental Study Of Rural Brick Burning In Iringa And Mbeya Regions, E Mushi

Tanzania Journal of Engineering and Technology (TJET)

In this paper results are presented Of a study conducted between June and December 1997. on nine brick firing kilns in Iringa and Mbeya. The locations for rhe study were Mahenje and Iloniba in Mbeya Region and Igumbilo in Iringa region. Three kilns were investigated in each location. For each kiln the process was followed from the laying Of the bricks into a kiln to the opening Of thc kiln for renu)val Of the bricks in preparation for the selling. Different weights and tenperatures were Taken a,' different times. Firing wet bricks results in consumption of 33.63 % of the …


Investigating Sorbent Geometry Response Surfaces From Sorption Rate Data, H. Michael Harrison Mar 1998

Investigating Sorbent Geometry Response Surfaces From Sorption Rate Data, H. Michael Harrison

Theses and Dissertations

Sorption and desorption of hydrophobic organic compounds (HOCs) into soil particles occurs at Air Force contamination sites. Long-term desorption extends clean up time, costing billions. Accurately modeling desorption will reduce costs and improve clean up designs. State of the art models depict soil as uniform spherical particles which lose the effect of longer sorption path lengths. An alternate approach, the multiple sites in series (MSS) model, describes the sorption capacity of a mixture of soil particle sizes and shapes using a composite particle defined by a two parameter statistical distribution. When the MSS model uses a general radial geometry function …


A Sociotechnical Systems Analysis Of The Approval Process For A Complex Public Works Proposal, James C. Pyne Apr 1997

A Sociotechnical Systems Analysis Of The Approval Process For A Complex Public Works Proposal, James C. Pyne

Engineering Management & Systems Engineering Theses & Dissertations

This research applied sociotechnical systems theory to explore the process used by two elected bodies to decide upon adoption of a complex technical engineering proposal. The research used a modified sociotechnical systems conceptual framework that was developed by Pava (1983) for application to non-traditional work settings. Pava applied the conceptual framework to what he termed non-routine office work which is characterized by non-linear conversion flow, multiple, concurrent conversion processes and vocational separatism (Pava, 1983).

The research was designed as a multiple case study of two town councils each undertaking a decision process to approve or reject a public works proposal …


Decision Support Model For Municipal Solid Waste Management At Department Of Defense Installations, John F. Muratore Dec 1995

Decision Support Model For Municipal Solid Waste Management At Department Of Defense Installations, John F. Muratore

Theses and Dissertations

This research focuses on the development of a decision support model to identify the preferred strategy for managing municipal solid waste using the principles of decision analysis theory. The model provides an effective decision making tool to evaluate and compare different municipal solid waste management strategies. The users of this model, the Environmental Manager or decision maker at a given installation, can enter installation-specific waste stream characteristics, treatment and disposal costs, and material buy-back prices to determine the expected value for various alternative strategies. The strategy having the greatest expected value is considered the preferred alternative. In calculating the expected …


Life-Cycle Cost Analysis For Radioactive Waste Remediation Alternatives, Thomas P. White, Ronald J. Toland, Dorian Y. Buitrago Mar 1995

Life-Cycle Cost Analysis For Radioactive Waste Remediation Alternatives, Thomas P. White, Ronald J. Toland, Dorian Y. Buitrago

Theses and Dissertations

This research has two primary objectives. The first is to develop a generic, interactive, spreadsheet-based life-cycle cost model that uses net present value and risk analysis techniques for cost comparison. The second is to apply the model specifically to the vitrification and cementation methods of waste remediation. By using spreadsheet analysis and graphics capabilities, the model will provide direct and objective comparisons of remediation alternatives. Since vitrification is a new technology, the plant design and operations are conceptual. Therefore, computer simulation and engineering judgement are integral to the vitrification LCC estimate.


Power Shedding Experiences And Lessons In A Township, Alexander Kyaruzi Dec 1994

Power Shedding Experiences And Lessons In A Township, Alexander Kyaruzi

Tanzania Journal of Engineering and Technology (TJET)

This paper presents how power shedding by taking out one of the trans- former high voltage fuses causes phase imbalance. And for the same elec- nicc,l energy output generator fuel consuntption with unbalanced phases is 12.5% of The fuel consunwtion with balanced phases. Furthermore it is shown thal energy efficient lighting by use of energy efficient bulbs can reduce load shedding.


Development Of A Knowledge-Based System For Wastewater Pipeline Rehabilitation, David Allen Reaves Oct 1994

Development Of A Knowledge-Based System For Wastewater Pipeline Rehabilitation, David Allen Reaves

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this thesis is to study and develop a knowledge-based system to make decisions for the rehabilitation of wastewater pipelines. Development includes justification for the use of an expert system, data acquisition from knowledge experts, program model development, model testing, implementation and future considerations including expansion. The model is developed and implemented using an expert system shell called XIPlus ®.

This knowledge-based system is designed specifically for the Navy Public Works Center Utilities Department at Norfolk Naval Base in Norfolk, Virginia for making decisions for the rehabilitation of the 50-year-old wastewater collection system. Recent sewer collapses and a …


Optimal Capacity Allocation Truck Industry In Tanzania:A Case Of National Transport Corporations(Ntc), R Mgaya Jun 1994

Optimal Capacity Allocation Truck Industry In Tanzania:A Case Of National Transport Corporations(Ntc), R Mgaya

Tanzania Journal of Engineering and Technology (TJET)

This paper tries to examine truck transportation service in Tanzania, particularly, in National Transport Corporation’s subsidiary companies - Regional Transport Companies. It provides an analysis based on operations research approach on resource allocation, specifically, truck allocation, with an aim of trying to minimize running costs and hence improve profits. It is established that there had been higher running costs and hence decline of profits in some Regional Transport Companies due to misallocation of capacity. However, this problem had been compounded by some other factors as discussed in the paper. It is recommended that these Regional Transport Companies and other transport …


Critical Evaluation Of The Effects Of Changes Made To Roughing Filters Of Mpira-Balaka Plant On Its Treatment And Operational Performance, C Zulu Dec 1993

Critical Evaluation Of The Effects Of Changes Made To Roughing Filters Of Mpira-Balaka Plant On Its Treatment And Operational Performance, C Zulu

Tanzania Journal of Engineering and Technology (TJET)

Mpira Balaka, a full scale rural water supply project was constructed in Ntcheu, Malawi, in 1988 utilising Slow Sand Filtration (SSF) as the main treatment process and roughing filtration as the pretreatment method,following the promo- tion of this technology by various international institutions. During the rainy seasons, the treatment plant for Mpira Balaka failed to cope with the high raw water turbidity, resulting into very short filter run times and hence also to unavoidable distribution Of very turbid water to the rural communi- ties as a result Of by-passing the filters. Of the fifty or so existing rural projects in …


A Decision Support Model Using Life Cycle Cost (Lcc) Analysis To Select Cost-Effective Alternatives For Hazardous Materials, Blaine F. Burley, Kirk A. Phillips Sep 1993

A Decision Support Model Using Life Cycle Cost (Lcc) Analysis To Select Cost-Effective Alternatives For Hazardous Materials, Blaine F. Burley, Kirk A. Phillips

Theses and Dissertations

This research focuses on the development of a decision support model to select cost-effective alternatives for hazardous materials using life cycle cost (LCC) analysis. The model provides an effective decision-making tool to evaluate the economic feasibility of using alternatives for hazardous materials. Given a specific operation, the users of this model can enter site-specific cost data to determine the total LCCs of using baseline hazardous materials (i.e., hazardous materials currently being used in an operation), as well as the total LCCs of using various alternatives. This thesis postulates that the material having the lowest total LCC is considered to be …


Hands-On Structural Engineering Experiences With The "Anex" Mini-Laboratory, Richard A. Behr, Colin Othniel Benjamin, Azam A. Mirza Dec 1992

Hands-On Structural Engineering Experiences With The "Anex" Mini-Laboratory, Richard A. Behr, Colin Othniel Benjamin, Azam A. Mirza

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The ANEX facility has been developed to allow nearly real-time comparisons of analysis results with experimental data gathered on small-scale structural models. ANEX has been used successfully for in-class demonstrations, student-designed experiments, and comprehensive design/build competitions in an introductory structural analysis course at the University of Missouri-Rolla. An expert system is now being developed to guide ANEX users and to act as a trouble-shooter and advisor in the event that analytical and experimental results do not correlate acceptably well. ANEX, using only simple, small-scale model structures, is able to enrich structural engineering instruction by introducing students to the sophisticated capabilities …


The Performance Of A Horizontal Flow Roughing Filter/Slow Sand Filter Water Treatment Plant In Tanzania, Mbwette T. A Jun 1992

The Performance Of A Horizontal Flow Roughing Filter/Slow Sand Filter Water Treatment Plant In Tanzania, Mbwette T. A

Tanzania Journal of Engineering and Technology (TJET)

The performance of a water treatment plant comprising of the Horizontal f Iow Roughing F i Iter (HRF) / Slow Sand Filter (SSF) System was evaluated by monitoring the water quality of the inlet water and the plant filtrates for a Improper operational procedures and period of two months. the absence of adequate maintenance of the plant was found to have resulted to relatively Iow removal efficiency. This subsequently improved as a result of plant rehabilitation and introduction of new operational procedures and became comparable to the performance of HRE/SSF plants documented in literature. For example, as a result of …


Parking Demand And Supply In The Central Business District Of Dar Es Salaam City, Theophil Rwebangira Dec 1991

Parking Demand And Supply In The Central Business District Of Dar Es Salaam City, Theophil Rwebangira

Tanzania Journal of Engineering and Technology (TJET)

The Central Business District (CBD) Of Dar es Salaam city is currently experiencing severe congestion. Among the major causes of this condition is lack cf enough parking facilities. Obstructions due to vehicles parked on the roadway and increased vehicle circulation by drivers looking for a mace to park This paper reports on a recent study are major contributors to congestion. which evaluated the demand and supply as vell as usage of parking spaces in the CED. The f indings indicate that there is currently an acute shortage Of parking spaces, especially of off—street parking spaces. For the existing facilities, there …


Design, Operation And Maintenance Considerations Of Iiorizontal Flow Roughing Filters Preceding Slow Sand Filters, T Mbwette, Dec 1991

Design, Operation And Maintenance Considerations Of Iiorizontal Flow Roughing Filters Preceding Slow Sand Filters, T Mbwette,

Tanzania Journal of Engineering and Technology (TJET)

The paper mentions some of the reported uses of Horizontal Flow Roughing Filters (IIRF) in drinking water treatment plants in Europe before briefly reviewing research activities carried out in the use of IIRF prior to Slow Sand Filters. Design, operation and maintenance aspects Of HRF are reviewed on the basis of the laboratory and field tests carried out in Tanzania and Switzerland, respectively in addition to experience gained in operation of a number of plants already built to date. Design aspects are introduced from the point of view Of its philosophy and optimization strategies before design guidelines are given. Important …