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2006

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Articles 1 - 18 of 18

Full-Text Articles in Risk Analysis

Characterization Of On-Road Petrol Vehicle Emissions Patterns In Dar Es Salaam City (Tanzania), Geoffrey John Dec 2006

Characterization Of On-Road Petrol Vehicle Emissions Patterns In Dar Es Salaam City (Tanzania), Geoffrey John

Tanzania Journal of Engineering and Technology (TJET)

Motor vehicle emissions have been identified to be the major source of air pollution in most urban cities. It has serious impact on urban air quality and public health. The Governments of many countries need to adopt stringent vehicle emissions regulations to protect the air quality, the undertaking of which can only be implemented once the problem at hand is known. In the present study, the characteristics of on road vehicle emissions from the selected local ar~as at the city of Dar es Salaam in a developing country for in-use petrol vehicles for urban driving conditions ranging from idling, lOkm/h …

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Performance Of Aerobic Bioreactors During Treatment Of Tanning Industry Wastewater, Samwel V. Manyele Dec 2006

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. …

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Determination Of Wind Loads Causing Flutter Effects, Ladislaus Lwambuka Dec 2006

Determination Of Wind Loads Causing Flutter Effects, Ladislaus Lwambuka

Tanzania Journal of Engineering and Technology (TJET)

A new method on the determination Of wind forces by experimental means in a wind tunnel is discussed. The method reported herein is based on the identification methodology Of model parameters under time response (i.e. time domain identification). As a test model, a thin plate Of Cypress wood, elasticully suspended in three degrees Of freedom to represent the idealized form of a classical airfoil, for Which theoretical wind load parameters exist, has been employed. Wind load parameters, experimentally obtained on the test model under the new method, are compared With the theoretical values of classical airfoils. Advantages of the new …

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An Intervention Framework Based On A Complementary Theory Of Organizational Decline, George S. Mwaluko Dec 2006

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 …

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Investigation On Distribution Of Cast Properties On Aluminum Plates Poured By Side Gating Technique, Joseph Runyoro Dec 2006

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 …

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Geophysical Exploration For Groundwater Resources Potential Over Basement Formations At Kwandolwa And Mwisho Wa Shamba Villages, Korogwe District, Tanzania, Cuthbert Mhilu Dec 2006

Geophysical Exploration For Groundwater Resources Potential Over Basement Formations At Kwandolwa And Mwisho Wa Shamba Villages, Korogwe District, Tanzania, Cuthbert Mhilu

Tanzania Journal of Engineering and Technology (TJET)

In this paper results of geophysical exploration studies to identify potential areas with groundwater resources at Kwamndolwa and Mwisho wa Shamba Villages in Korogwe District have been presented. The resistivity curves of eight sites at the two study areas were obtained using field data measurements made based on the application of a vertical electrical sounding (VES) method. The resisivity values obtained for sites VES-K3 and VES-M2 were found to be 10.9 and 24.0 ohm-m respectively. The interpretation of the resisivity values made for the two sites gave also an indication of the presence of sedimentary rocks composed of sandstone materials …

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Sampling Procedure For Pavement Condition Evaluation Of Local Collectors And Access Roads, David Mfinanga Dec 2006

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 …

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Towards Effective Online Learning Implementation In Tanzanian Higher Learning Institutions: Obstacles, Challenges And Opportunities, M Victor Dec 2006

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 …

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Study On Vortex Formation In The Pouring Basin By Direct Observation, J Runyoro Jun 2006

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 …

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Suitability Of Crusher-Dust As Masonry Construction Material, John Makunza Jun 2006

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 …

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Effectiveness Of Hot Isostatic Pressing On Healing Oxide Film Defects In Cast Aluminium Alloys, C Nyahumwa Jun 2006

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 …

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Comparison Of Two Different Transport Models To Predict Sediment Transport: Simiyu River, Tanzania, Case Study, F Mwanuzi1 Jun 2006

Comparison Of Two Different Transport Models To Predict Sediment Transport: Simiyu River, Tanzania, Case Study, F Mwanuzi1

Tanzania Journal of Engineering and Technology (TJET)

This paper presents the results of a study which focused at the spatial and temporal characteristics of sediment transport and deposition in the main river channels and floodplains. Two different numerical models were used to simulate stream flow and to analyze sediment transport and deposition in the river channels: (1) the SMS modules RMA2 and SED2D and (2) the SCALDIS model developed at the Free University of Brussels. Both numerical models contain a two-dimensional hydrodynamic module and a sediment transport module, allowing simulation of stream flow and sediment transport processes in river channels. However, they differ in the following aspects: …

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Overview Of Hydraulics And Simiyu River Sediment Input Into Magu Bay, Lake Victoria, Tanzania, Alfonse Dubi Jun 2006

Overview Of Hydraulics And Simiyu River Sediment Input Into Magu Bay, Lake Victoria, Tanzania, Alfonse Dubi

Tanzania Journal of Engineering and Technology (TJET)

Lake Victoria is experiencing multifaceted environmental and ecological problems. A  study of the problems needs a multidisciplinary approach. to establish the cause-effect relationships. The study focuses on the hydraulics of Lake Victoria's Magu Bay and Simiyu riverine input of suspended sediments and their distribution in the Bay. Sampling in the river mouth and the Bay was conducted aboard an 8m outboard engine wooden boat. Turbidity, currents speed and direction were measured using an "AANDERAA" multi-sensor self-recording current meter model 9 (RCM9). Water depth was measured using an echo-sounder type FISHIN' BUDDY II. Geographical positions of the sampling locations were obtained …

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Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor Jun 2006

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 …

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Investigation Of The Stability Of Engine – Governor System Operated At Low Speeds, Cuthbert Mhilu Jun 2006

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 …

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Environmental Impact Of Wetland Resources Utilization In Simuyu Basin, Tanzania, Shadrack Mwakalila Jun 2006

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 …

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Mitigating Insider Threat Using Human Behavior Influence Models, Anthony J. Puleo Jun 2006

Mitigating Insider Threat Using Human Behavior Influence Models, Anthony J. Puleo

Theses and Dissertations

Insider threat is rapidly becoming the largest information security problem that organizations face. With large numbers of personnel having access to internal systems, it is becoming increasingly difficult to protect organizations from malicious insiders. The typical methods of mitigating insider threat are simply not working, primarily because this threat is a people problem, and most mitigation strategies are geared towards profiling and anomaly detection, which are problematic at best. As a result, a new type of model is proposed in this thesis, one that incorporates risk management with human behavioral science. The new risk-based model focuses on observable influences that …

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Formal Mitigation Strategies For The Insider Threat: A Security Model And Risk Analysis Framework, Jonathan W. Butts Mar 2006

Formal Mitigation Strategies For The Insider Threat: A Security Model And Risk Analysis Framework, Jonathan W. Butts

Theses and Dissertations

The advancement of technology and reliance on information systems have fostered an environment of sharing and trust. The rapid growth and dependence on these systems, however, creates an increased risk associated with the insider threat. The insider threat is one of the most challenging problems facing the security of information systems because the insider already has capabilities within the system. Despite research efforts to prevent and detect insiders, organizations remain susceptible to this threat because of inadequate security policies and a willingness of some individuals to betray their organization. To investigate these issues, a formal security model and risk analysis …

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