Operations Research, Systems Engineering and Industrial Engineering Commons^™

Hazard Identification, Risk Assessment And Risk Control (Hirarc) In A Corrugated Box Manufacturer., Fraziel Barahim

Student Works (2010-2019)

Packaging is one of the biggest industries in the world. It involves paper, glass,metal, flexible and plastic. The corrugated paper packaging worldwide has been growing at 3% to 4% per annum. In line with the expansion of the corrugated paper packaging manufacturing, the potential hazards to human physical and health, property and the environment posed by its operations and production activities have created an increase in awareness and brought up safety issues amongst industry, government and public. The hazard identification and risk assessment plays a role in a number of areas in the safety management, including regulatory policies and guidelines, …

Project And Risk Management: A Systematic Approach, Baqer Alali, C. Ariel Pinto, Andreas Tolk, Rafael Landaeta

Engineering Management & Systems Engineering Faculty Publications

The main purpose of this paper is to discuss three related topics of project management, systems management, and risk management. The issue that would be addressed in this paper is how risks are addressed in project and systems management, and how risks are propagated between projects and systems. A framework is proposed to overcome the problem of risk propagation from project to the systems. It was shown that the proposed framework can be deployed to existing risk management process with reasonable interventions (e.g. process prescribed by PMI). Finally a proof-of-concept application shows potential of the framework for various types of …

Application Of Systems Engineering To Rapid Prototyping For Close Air Support, John M. Colombi, Richard G. Cobb

Faculty Publications

Twenty-first century military operations have brought forth many new challenges for the Armed Forces of the United States. One such challenge is with new operating environments, where current systems are not always effective. While it is desirable to apply a systems engineering approach to best meet critical user needs, there may be a misconception that systems engineering requires a lengthy and detailed process not nimble enough for a rapid prototyping effort. This article describes how a classic systems engineering methodology was successfully tailored to the rapid development of potential material solutions to meet a critical operational need. Key observations are …

Sensitivity Analysis Framework For Large And Complex Simulation Models, Ghaith Rabadi, Shannon Bowling, Charles Keating, Resit Unal

Engineering Management & Systems Engineering Faculty Publications

In this paper, a framework for conducting Sensitivity Analysis (SA) on large and complex simulation models is introduced. The framework consists of components that are designed to make the SA a systematic process that is easy to manage and follow by simulation analysts and practitioners. Unlike local SA (one-variable-at-a-time SA), the method presented here is variance-based and it is rooted in the field of Design of Experiments (DoE) where Input Variables are varied and Output Variables are measured. Based on the DoE results, a risk scoring system is developed to identify the sensitivity of the Input Variables, and as a …

Improving The Design Of Low Volume Sealed Roads In Tanzania, Mfinanga A

Tanzania Journal of Engineering and Technology (TJET)

The main objective of the study was to identify appropriate road designs for Low Volume Sealed Roads (LVSRs) with the aim of improving the design of such roads in Tanzania. The study was conducted in Dar es Salaam and Morogoro regions in Tanzania where data for LVSRs were collected from primary and secondary sources in the two regions. The study found that by using an improved pavement design method specifically meant for LVSRs results in cost savings for LVSRs of up to 51% compared with the conventional method of pavement design in Tanzania. The study recommends that the pavement design …

The Effect Of Rotation And Temperature On The Inhibition Performance Of Cashew (Anacardium Occidentale L.) Nut Shell Liquid On Co2 Corrosion Of Carbon Steel, J Mutasingwa

Tanzania Journal of Engineering and Technology (TJET)

A natural extract of cashew nut shells, Cashew Nut Shell Liquid (CNSL) was investigated as a corrosion inhibitor for carbon steel in 3% NaCl solutions saturated with CO2 gas using electrochemical techniques (i.e. potentiodynamic polarization and ac-impedance). The investigation was performed at different temperatures under static and dynamic conditions using a Rotating Disk Electrode (RDE). It was found that CNSL reduces the electrochemical processes taking place on carbon steel undergoing corrosion. The percentage inhibitor efficiency increases with increase in CNSL concentration and decreases with rise in temperature. Better performance at low CNSL concentration was registered under dynamic conditions and room …

Potential Use Of Waterguard As A Disinfectant For Domestic Water Use, Yohana L

Tanzania Journal of Engineering and Technology (TJET)

been identified as an alternative method for treatment of domestic drinking water. The aim of this study was to investigate the effectiveness of Water Guard in disinfecting drinking water from different sources drawn from Kinondoni district, Dar es Salaam as well as to establish appropriate dosage that can be used during the treatment. Results showed that, a dose of 4.0mL per 20 litrer of water guard is sufficient for disinfection of urban water sources. The above prescribed doses provide 100% disinfection efficiency with residue chlorine of less than 0.3mg/l. Water with turbidity values of 30-35 NTU, chlorine dosage of 8mL/20 …

Investigation Of The Effect Of Particle Size On Groundnut-Oil Solvent Extraction, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

An investigation of the effect of particle size on the performance of vegetable oil recovery by solvent extraction is reported. Experiments were conducted using soxhlet extractor, groundnuts and n-hexane. Samples were grouped into mean particle sizes of 0.25, 0.75, 1.3, 3.3, and 7.5 mm using standard sieves. The effect of particle size was studied for extraction time intervals of 1, 2, 3, 4, 5 and 8 hours. The oil yield, oil recovered per kg solvent used, kg solvent lost per unit time, and the rate of extraction (kg oil recovered per hour) decreased with increasing particle size. Meanwhile, the percent …

The Systemic Nature Of Action Learning Programmes, G Mwaluko

Tanzania Journal of Engineering and Technology (TJET)

A lot of attention has been paid on action learning in the last four decades or so and the success of such programmes has also been widely publicized. But why have these programmes been so effective in helping organizations cope with change? Many authors state that the success of such programmes is due to the fact that they link learning to actions. Yet others claim that action learning programmes succeed because they involve employee empowerment and provide a much greater learning curve. In this paper the authors hold that action learning programmes succeed because they are partly systemic and can …

Identification Of Unbalanced Forces And Foundation Parameters Of Rotating Machines From Vibration Measurements, Nalitolela G

Tanzania Journal of Engineering and Technology (TJET)

A technique is described to use measured vibration data of a rotating machine and its foundation to identify unbalanced forces, stiffness and damping parameters of the mountings, and the parameters of the foundation. It is based on an idealisation treating the rotor, the machine structure and the foundation as rigid masses supported by springs and dampers. Operational vibration data of the machine and its foundation before and after the rotating unbalanced forces are perturbed by adding unbalanced mass to the rotor are used in the identification procedure. Once the parameters are identified, dynamic forces transmitted to the foundation can be …

Application Of Non-Destructive Testing In Evaluating Reinforced Concrete Structural Elements In Buildings, I Rubaratuka

Tanzania Journal of Engineering and Technology (TJET)

Of recent a large number of existing reinforced concrete buildings have required reconstruction, renovation and improvement. This tendency poses a number of problems that have to be solved, the main one being to determine the actual strength condition of the structural components/elements of the building. It includes determination of the quality of materials used, specification of the types and description of apparent faults and damages and extent of wear of the building. To undertake this evaluation, non – destructive testing methods are used. In this paper, applications of non – destructive testing methods to determine the strength state of reinforced …

Quality Control In The Construction Of Reinforced Concrete Buildings In Dar Es Salaam, I Rubaratuka

Tanzania Journal of Engineering and Technology (TJET)

Quality Control in the construction industry is very important to ensure that what is being done conforms to the applicable standards or good practice and the contract documents. In this article, results of investigations conducted at different construction sites for reinforced concrete buildings in Dar es Salaam to check if quality control measures are being implemented are discussed. It has been established that generally quality control is not properly carried out. Finally, measures to enhance quality control on sites are outlined.

Strategies For Promoting The Use Of Concrete Pavements In Tanzania: Technical And Institutional Considerations, Mfinanga A

Tanzania Journal of Engineering and Technology (TJET)

High-type roads in Tanzania have been predominantly of asphaltic concrete construction. This ever enlarging and ageing asphaltic road network represents increasing resource requirements on the road agency in the form of maintenance. Limited resources coupled with the ever sky-rocketing costs of petroleum products and the competing demands of social economic developments, presupposes the need to look for alternative road construction technology that is more cost-effective and resource optimising. Experience gained from developed and some developing countries where concrete pavements have been widely used suggests the potential of this type of pavement in many developing countries. This paper discusses the technical …

Uncertainty Assessment In High-Risk Environments Using Probability, Evidence Theory And Expert Judgment Elicitation, Stella Barberis Bondi

Engineering Management & Systems Engineering Theses & Dissertations

The level of uncertainty in advanced system design is assessed by comparing the results of expert judgment elicitation to probability and evidence theory. This research shows how one type of monotone measure, namely Dempster-Shafer Theory of Evidence can expand the framework of uncertainty to provide decision makers a more robust solution space. The issues imbedded in this research are focused on how the relevant predictive uncertainty produced by similar action is measured.

This methodology uses the established approach from traditional probability theory and Dempster-Shafer evidence theory to combine two classes of uncertainty, aleatory and epistemic. Probability theory provides the mathematical …

A Layered Social And Operational Network Analysis, Jennifer L. Geffre

Theses and Dissertations

To provide maximal disruption to a clandestine/terrorist network's ability to conduct missions, we must develop a means to determine the individuals' importance to the network and operations. In a network centric world, this importance is represented as an additive value of their criticality across the convergence of multiple layers of network connections. The connections layers of the network are comprised of social layers (Acquaintance, Friendship, Nuclear Family, Relatives, Student-Teacher, and Religious Mentors, Reverent Power and others), as well as layers representing interactions involving Resources, Knowledge/Skills and Temporal Local. The social criticality of an individual is measured by centrality. Event Trees …

Updating Optimal Decisions Using Game Theory And Exploring Risk Behavior Through Response Surface Methodology, Jeremy D. Jordan

Theses and Dissertations

This thesis utilizes game theory within a framework for updating optimal decisions based on new information as it becomes available. Methodology is developed that allows a decision maker to change his perceived optimal policy based on available knowledge of the opponents strategy, where the opponent is a rational decision maker or a random component nature. Utility theory is applied to account for the different risk preferences of the decision makers. Furthermore, response surface methodology is used to explore good risk strategies for the decision maker to approach each situation with. The techniques are applied to a combat scenario, a football …

Performance Of Aerobic Bioreactors During Treatment Of Tanning Industry Wastewater, Samwel V. Manyele

Tanzania Journal of Engineering and Technology (TJET)

The performance of aerobic bioreactors loaded with novel biomass support (the KMT® support particles) during the treatment of tanning industry wastewater is presented in this paper. The wastewater samples were collected from TANWAT Company in Njombe, which extracts tannins from barks of the wattle tree. The wastewater generated from T ANWAT is very acidic with high loading of organic compounds, which are very complex and difficult to biodegrade using conventional methods. The paper introduces a new technology for treatment of heavily loaded industrial wastewater, like tannins, that is the Three-Phase Fluidized Bed Bioreactor (TPFBB) which utilizes the KM'f® support particles. …

An Intervention Framework Based On A Complementary Theory Of Organizational Decline, George S. Mwaluko

Tanzania Journal of Engineering and Technology (TJET)

This paper has developed an intervention framework based a complementary theory Of Organization decline. Any management intervention effort is normally based on a certain theory of organizational decline i.e. a theory that explains the causes for failure of organizations. Four major theories Of Organisational decline were identified in the literature, reviewed and integrated into one, presumably more superior, theory of organisational decline. They included the natural selection theory, the resourc+based theory, the theory Of misperception of feed!mck and the contingency theory. The new theory was then used to guide the design of an intervention framework. The framework utas then used …

Investigation On Distribution Of Cast Properties On Aluminum Plates Poured By Side Gating Technique, Joseph Runyoro

Tanzania Journal of Engineering and Technology (TJET)

Casting technologies wllich improve casting yield and intenzal sOllndness of thin wall cast components are of particular interest to industry especially for critical applications. The main aim of fOll1ldries is to achieve castings free from defects at low cost. It hils been thought that pouring casting by side ingate technique improve directional solidification as the metal stays hot for long time in the feeder cum ingate. Experiments were carried alit IIsing a side gating technique to cast a number of 300 mm x 300 mm LMO and LM 25 plates in furall and pepset sand moulds. The thickness used was …

Sampling Procedure For Pavement Condition Evaluation Of Local Collectors And Access Roads, David Mfinanga

Tanzania Journal of Engineering and Technology (TJET)

Road surface condition evaluation involves the collection Of a lof Of data on different types of distresses. •lie exercise consumes a lot Of resources if the whole road section length is sureeyed and may be prone to errors as a result Of surveyors' fatigue. It is therefore important Io develop n reprevntative sample to be used When road condition manually. This study aimed nt determining sample size for condition evaluation of local collector access roads in urban areas in Tanzania. Two such roads namely l.ufungira and Kilimahewn roads respectively were selected for the study. It is recommended that a section …

Towards Effective Online Learning Implementation In Tanzanian Higher Learning Institutions: Obstacles, Challenges And Opportunities, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper identifies and discusses several influential factors as well as opportunities, associated with effective- online learning implementation in Tanzanian Higher Learning Institutions (THUs). Fourteen (14) THUs were surveyed, using face-to-face interviews in focus groups. The groups included Lecturers, Heads of ICT Departments, ICT Technical Personnel as well as Admi/:listrative Staff. Results indicate that mostly, problems with effective online implementation in THUs are centred on a severe scarcity of online resources and tools and that the main challenges lie in going beyond the process of integrating technology with their teaching curricular, so that training of both teaching and supporting staffs …

Study On Vortex Formation In The Pouring Basin By Direct Observation, J Runyoro

Tanzania Journal of Engineering and Technology (TJET)

Although the formation of vortex on the free surface of liquid draining from a container is often observed, relatively little is known about the phenomenon. When a liquid is drained from a container such as a bathtub through a bottom orifice, a dip on the surface known as vortex is formed. The vortex first appears as a small dimple in the free surface, which suddenly forms a cone-shaped hole. The vortex causes turbulences, which draws in air down into the orifice (drain). Generally, the issue of vortex formation is so common in our lives that possibly its occurrence seems to …

Suitability Of Crusher-Dust As Masonry Construction Material, John Makunza

Tanzania Journal of Engineering and Technology (TJET)

Crusher dust generated at Kunduchi quarries in Dar es Salaam during aggregate crushing is counted as a waste material, and some times it .is disposed away or sold at a cheap price of not more than a quarter of that of sand. A study on the use of the crusher dust as a building material has been carried out in which samples were collected and analyzed for grading (sieve analysis). In additional to that, other samples were stabilized with a small amount of cement, from which bricks were produced and tested for compressive strength. Other bricks were bonded together using …

Effectiveness Of Hot Isostatic Pressing On Healing Oxide Film Defects In Cast Aluminium Alloys, C Nyahumwa

Tanzania Journal of Engineering and Technology (TJET)

Hot isostatic pressing (hipping) of cast aluminium alloys is recognized as a means of providing improved internal soundness and mechanical properties of the castings. However, little is known about the limitations and potential benefit of the hipping process to produce reliable aluminium alloy castings containing oxide film defects due to turbulently filling of moulds. In this study, oxide film defects and fatigue lives of turbule''Zt filled unfiltered AI-7Si-Mg alloy castings have been characterised in as-cast and hipped. conditions to quantify the effectiveness of hot isostatic pressing on healing oxide film defects in the castings. The average fatigue life and fatigue …

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …

Investigation Of The Stability Of Engine – Governor System Operated At Low Speeds, Cuthbert Mhilu

Tanzania Journal of Engineering and Technology (TJET)

During diesel engine operation, a tendency for the engine not to achieve a  steady idling speed has often been observed. During idling speed the engine tends to either race or stall as a result of poor and incorrect metering of the fuel, which is required for the combustion process and if severe, the engine will stop firing completely. 111 this research an investigation was made to establish knowledge on diesel engine stability operated at low speeds. The influence of a governor of an engine in the control of the engine speeds has also been investigated. In order to obtain information …

Environmental Impact Of Wetland Resources Utilization In Simuyu Basin, Tanzania, Shadrack Mwakalila

Tanzania Journal of Engineering and Technology (TJET)

There is a growing appreciation of the natural functions of wetlands, and the values and different forms of uses that humans attach to them. Wise use and special conservation strategies are therefore needed in order to sustain their productivity. Wetlands are one of the most fruitful areas of archaeological research, and they are the ideal setting in which to study the interactions between physical processes and human actions that encapsulate and exemplify many of the themes of man's impact on his environment. But all these beneficial functions of wetlands seem to be in danger of being lost to draining and …

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. …

Study Of The Impact Of Quality Costs On Profitability: The Case Of Small And Medium Industries In Tanazania, B Kundi

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.

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 …