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Auditing Of Traffic Signs And Road Markings In Dar Es Salaam City, Hannibal Bwire
Auditing Of Traffic Signs And Road Markings In Dar Es Salaam City, Hannibal Bwire
Tanzania Journal of Engineering and Technology (TJET)
This study examines the efficacy of the traffic signs and road markings in Dar es Salaam City. The study focuses on the availability and conditions of traffic signs and road markings in some selected roads in the city. Auditing of traffic signs and road markings is carried out as one of the means of promoting road safety and improving road capacity in the city. The auditing procedure involved field studies through the use of traffic signs/markings checklists and ranking of road stretches according to the availability and conditions of traffic signs observed for improvement prioritization in case of financial constraints. …
The “Tea Cup Effect” And Removal Of Suspended Solids From Water, D.A. Mashauri
The “Tea Cup Effect” And Removal Of Suspended Solids From Water, D.A. Mashauri
Tanzania Journal of Engineering and Technology (TJET)
Suspended solids problem in water is an issue as old as water treatment itself. Suspended solids can be causative to eroding through abrasion of impellers, pump casings, pipes and other water works related appurtenances. It is therefore appropriate that suspended solids must be removed as early as possible in the water works treatment facilities. It is usually done at the river/lake intakes to reduce the coarse particulate matter that would otherwise adversely affect the water works thereafter. The fine particles that will escape the entrapment at the intake works would therefore require further and more effective system that would remove …
Design And Development Of A Prototype For A Web-Based Interface For Online Material For Tanzanian Youth, Mjema A.M
Tanzania Journal of Engineering and Technology (TJET)
A prototype of a web-based interface for an online database was developed to be used by youth organizations in Dar-es-Salaam. A participatory approach involving secondary students in the identification of user interface requirements, in designing and testing the prototype was used. A questionnaire was designed and manned in seven secondary schools in Dar-es-Salaam to estimate the Internet usage. Interviews were conducted to countercheck the questionnaire responses. The interview and the questionnaire helped to come up with a set of user requirements for the web-based interface of an online information search. From the specifications of the user requirements the author was …
The Systemic Nature Of Action Learning Programmes, G Mwaluko
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 …
Analytical Modeling Of A Large Local Area Network - Part I: Internet Traffic Characterization, Mathew Luhanga
Analytical Modeling Of A Large Local Area Network - Part I: Internet Traffic Characterization, Mathew Luhanga
Tanzania Journal of Engineering and Technology (TJET)
The goal of both IP network operators and the end users is to get the highest performance from the system for a given cost. This makes Performance a key criterion in the design, procurement, and use of computer and communication systems. In order to address problems associated with performance degradation of operational communications systems, over the last decade, traffic engineering techniques have emerged in an attempt to optimize communication systems’ performance and ensure more efficient use of their resources. One of these techniques is analytical modeling. Analytic performance models are an excellent tool for quickly evaluating the performance of operational …
Improving The Design Of Low Volume Sealed Roads In Tanzania, Mfinanga 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 …
Integrated Remote Sensing And Gis Techniques For Groundwater Exploration In Semi-Arid Region: A Case Of Karamoja Region – Uganda, Lubang Nobert
Integrated Remote Sensing And Gis Techniques For Groundwater Exploration In Semi-Arid Region: A Case Of Karamoja Region – Uganda, Lubang Nobert
Tanzania Journal of Engineering and Technology (TJET)
Groundwater is a precious resource that covers wide geographical extent. Proper evaluation is required in order to ensure prudent use of groundwater resources. The current groundwater assessment in Karamoja region, as in many parts of the world, uses Apparent Resistivity and Vertical Electrical Sounding, which has limited coverage to some localized usually predetermined areas. Comprehensive groundwater development program needs a wide area coverage and large volume of multidisciplinary data. In the present study, an integrated remote sensing and GIS based methodology is developed and tested for the evaluation of groundwater resources of Karamoja Sub Region, Northeastern Uganda. The components of …
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
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
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 …
Identification Of Unbalanced Forces And Foundation Parameters Of Rotating Machines From Vibration Measurements, Nalitolela G
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 …
The Multivariate Statistical Analysis Of Abiotic Parameters Of The Lake Tanganyika Sub Catchment, Hudson Nkotagu
The Multivariate Statistical Analysis Of Abiotic Parameters Of The Lake Tanganyika Sub Catchment, Hudson Nkotagu
Tanzania Journal of Engineering and Technology (TJET)
Results from multivariate statistical analysis of abiotic parameters conducted during the dry season at 20 accessible sites on 8 rivers, 2 lakes and a dam covering the Lake Tanganyika sub catchment are discussed. Standard methods were used to determine the levels of abiotic parameters from water samples. Physical parameters including DO, EC, Eh, turbidity, temperature, pH and secchi transparency were measured in situ while chlorophyll a was determined in the laboratory. Nutrients such as NO3-, SiO2, PO4 3- and Fe2+ were determined along with HCO3-. Factor analysis resulted in four factors including increased primary productivity, redox conditions, dissolution, and reduction …
An Equation For Estimating The (R) Usle Slope Steepness Factors, Mathew Mulemgera
An Equation For Estimating The (R) Usle Slope Steepness Factors, Mathew Mulemgera
Tanzania Journal of Engineering and Technology (TJET)
Abstract Currently three equations are used for calculating slope steepness factor for the Revised Universal Soil Loss Equation (RUSLE); one for slopes less than nine percent, the second for slopes equal or greater than nine percent, and the third equation that has been proposed for use in China for slopes equal or greater than 17 %. The three equations have linear relationships between slope steepness factor, S and the sine of the slope angle, θ. The three equations under predict the factor, S when used on slope steepness beyond the data sets used to develop them. In addressing this problem …
Accuracy Analysis For Kolmogorov Entropy Used In Studying The Chaotic Dynamics Of Cfb Reactors Based On Solids Concentration Fluctuations, Samwel V. Manyele
Accuracy Analysis For Kolmogorov Entropy Used In Studying The Chaotic Dynamics Of Cfb Reactors Based On Solids Concentration Fluctuations, Samwel V. Manyele
Tanzania Journal of Engineering and Technology (TJET)
A study on the chaotic dynamics of a high flux circulating fluidized bed (CFB) riser (10-m high and 76-mm i.d.) using the maximum likelihood estimate of the Kolmogorov entropy (KML) is reported. The signals used were measured by using a solids concentration fiber optic probe, accuracy of which is reported based on statistical analysis. The sensitivity analysis of the parameters used for computing KML was conducted to identify optimum settings, based on the standard error, s(KML) and the nature of PDF of the b-values from the reconstructed phase space trajectories. The length of time series, N, sampling frequency, fs, and …
Trends Of Rainfall And Maize Productivity In Malawi, T Kimaro
Trends Of Rainfall And Maize Productivity In Malawi, T Kimaro
Tanzania Journal of Engineering and Technology (TJET)
Daily rainfall data between 1966 and 2005 across all Agricultural Development Areas (ADDs) in Malawi was investigated to determine changes in selected rainfall characteristics and their impact on Maize productivity. Rainfall indices analyzed included rainfall amounts (annual and seasonal), onset, cessation, dry spells and length of rainy season. Man Kendal’s trend test was applied to the time series of these indices to detect any trends in the time series. Water Requirement Satisfaction Index (WRSI) for maize crop was used to study the spatial-temporal variation of maize productivity and thus its linkage to rainfall. Definition of onset and cessation adopted from …
Improving The Availability Of Manufacturability Information Through Decentralization Of Process Planning, Eliab Opiyo
Improving The Availability Of Manufacturability Information Through Decentralization Of Process Planning, Eliab Opiyo
Tanzania Journal of Engineering and Technology (TJET)
Process planning is part of the general product development and production process that usually follows design and precedes manufacturing. Manufacturability and process planning information in general play central role in many product development and production activities, including paradoxically, conceptual and detail design - the activities that take place before process planning. The need of conducting some of the process planning activities formally before or during design is thus rather obvious. One of the main research issues is therefore the identification of the process planning activities that can be performed before the traditional process planning phase and handling of the process …
Development Of A Genetic Algorithm Based Search Strategy Suited For Design Optimisation Of Internal Combustion Engines, Nalitolela G
Development Of A Genetic Algorithm Based Search Strategy Suited For Design Optimisation Of Internal Combustion Engines, Nalitolela G
Tanzania Journal of Engineering and Technology (TJET)
Engine design optimisation is a multi-objective, multi-domain problem in a discontinuous design space. The state of the art of optimisation techniques shows that only methods of direct and adaptive search are appropriate for this type of problem. These include, adaptive random search, simulated annealing, evolution strategies and genetic algorithms. Of these methods, the genetic algorithms have been shown to be the most suited for the optimisation of multi-modal response functions in a discontinuous design space. This paper considers the important characteristics of genetic algorithms and their adaptation for use in parametric design optimisation of internal combustion engines. In order to …
The Limnogeology Of The Lakes Sagara And Nyamagoma, Hudson Nkotagu
The Limnogeology Of The Lakes Sagara And Nyamagoma, Hudson Nkotagu
Tanzania Journal of Engineering and Technology (TJET)
The present study focuses on the limnogeological aspects of the lakes Sagara and Nyamagoma within the Malagarasi Wetland Ecosystem. Abiotic parameters from water and sediment samples were determined during the dry and wet seasons using appropriate gears and methods. The data show variation of the abiotic parameters in both lakes from the water surface to the bottom. Lake Nyamagoma is less turbid (0.7-24 NTU) than Lake Sagara (25 to 65 NTU). The water transparency was also high at Lake Nyamagoma (0.75-1.5 m) thus supporting the observed turbidity trend. The physical chemical changes may be attributed to processes such as cooling, …
Modeling Of A Spray Assisted Natural Draft Cooling Tower, Kaunde K
Modeling Of A Spray Assisted Natural Draft Cooling Tower, Kaunde K
Tanzania Journal of Engineering and Technology (TJET)
Cooling towers are one of the largest heat and mass transfer devices that are in common use. A novel type of cooling tower has been proposed in which air flow rate into the tower is drawn by ejector action of sprays instead of fans as is done in conventional mechanical forced or induced draft cooling towers. This novel design offers the potential of saving the energy cost for driving the fan. The paper presents mathematical models for momentum transfer which is the driving force causing the entrainment of air. Also the heat transfer model for co-current flow of liquid and …
Application Of Non-Destructive Testing In Evaluating Reinforced Concrete Structural Elements In Buildings, I Rubaratuka
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 …
Assessment Of Integrated Water Resources Management Practice In Yatta Canal, Machakos District, Kenya, Lawrence Simitu
Assessment Of Integrated Water Resources Management Practice In Yatta Canal, Machakos District, Kenya, Lawrence Simitu
Tanzania Journal of Engineering and Technology (TJET)
Yatta Canal is situated in Yatta division, Machakos district about 100 km from Nairobi along Thika- Garissa road. It is about 60 Km long and supplies water for domestic, livestock and irrigation use. Over the years, the water supply has been unreliable especially during dry season leading to conflicts between upstream and downstream consumers. Sometimes the Government has been forced to intervene to restore order. The study aimed at assessing the use of Yatta canal, based on the principles of Integrated Water Resources Management (IWRM) which stipulates efficient use of water and involvement of all stakeholders in decision making for …
Sediment Yield Prediction In Tanzania: Case Study Of Dodoma District Catchments, Mathew Mulemgera
Sediment Yield Prediction In Tanzania: Case Study Of Dodoma District Catchments, Mathew Mulemgera
Tanzania Journal of Engineering and Technology (TJET)
Soil erosion and sedimentation is serious and is resulting in rapid sedimentation of streams and reservoirs in Tanzania. This makes sediment yield modeling important before undertaking water resources development projects, although it has so far not been done in the country. At present sediment yield prediction can be done using physically based models, empirical soil erosion and sediment yield models, and sediment rating curves. The physically based models contain numerous parameters that are difficult to measure or estimate, making them inappropriate in developing countries like Tanzania. The rating curves give rough estimates while the empirical sediment yield models need runoff …
Quality Control In The Construction Of Reinforced Concrete Buildings In Dar Es Salaam, I Rubaratuka
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.
Sedimentation Status Of Lake Victoria: Loading From River Mouth And In-Lake Sedimentation, F Mwanuzi1
Sedimentation Status Of Lake Victoria: Loading From River Mouth And In-Lake Sedimentation, F Mwanuzi1
Tanzania Journal of Engineering and Technology (TJET)
Lake sediments consist of the input of suspended solids by river discharges, the autochthonous produced particulate matter in the water column and the settled material on the lake bottom. The loading, transport, formation and decay of the sediments entering the Lake Victoria from Tanzanian side was monitored for the period 2000 to 2005. The sedimentation study focused on; quantification of settling fluxes of particulate nutrients and organic carbon at the off shore(Pelagic) and near-shore(Littoral) monitoring stations. Monitored data on sedimentation rate and settling velocities has been sampled and analysed in the period November 2000 to March 2005. The mean sedimentation …
Open Source Software In Health Information Systems: Opportunities And Challenges, Hashim Twaakyondo
Open Source Software In Health Information Systems: Opportunities And Challenges, Hashim Twaakyondo
Tanzania Journal of Engineering and Technology (TJET)
The paper presents results of a study seeking to identify constraining and motivating factors associated with the adoption and use of Free Open Source Software to computerise health Information Systems in a developing country. The study approach is interpretive research to case study with a triangulation of several qualitative data collection methods such as interviews, group discussions and document analysis. The findings indicate that using open source software has advantages and disadvantages. The advantages are low entry cost to adopting software, possibilities of software localization, avoiding being hostage of proprietary software and foster knowledge acquisition among software developers. The disadvantages …
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 …
Nyumba Ya Mungu Reservoir System Simulation By Using Hec-Ressim Model, Deogratias Mulungu
Nyumba Ya Mungu Reservoir System Simulation By Using Hec-Ressim Model, Deogratias Mulungu
Tanzania Journal of Engineering and Technology (TJET)
This research paper focused on estimating effective water and optimization of the NyM reservoir for storage conservation and hydropower generation. Several models were used in the study: the Rainfall-Runoff model, GFFS was used to fill in missing data, and the HEC-ResSim Model and the NWBM for reservoir system simulation and water balance respectively. The effective inflows to the NyM reservoir were determined using HEC-ResSim model and the NWBM used to check the total water loss in the system. For the reservoir system simulation, the HEC-ResSim model was used to estimate water loss through irrigation abstractions in Kikuletwa and Ruvu reaches …
Socio-Economic Impacts Of Water Scarcity In Dar Es Salaam, Tanzania, Shadrack Mwakalila
Socio-Economic Impacts Of Water Scarcity In Dar Es Salaam, Tanzania, Shadrack Mwakalila
Tanzania Journal of Engineering and Technology (TJET)
Drought and the resulting low water levels in rivers exacerbate water scarcity conditions in Dar es Salaam city. The result is frequent water rationing in areas served with piped water, sometimes for days or weeks, and low water pressure, which leads residents to resort to other less safe and sometimes more expensive water sources. The frequent and current response to the inadequate piped water supply in Dar es Salaam has been the use of groundwater resources. There are both public and private bore-holes and wells drilling companies in Dar es Salaam.. This paper therefore, presents some socio-economic impacts of water …
Program For The Analysis Of Plane Trusses, John Makunza
Program For The Analysis Of Plane Trusses, John Makunza
Tanzania Journal of Engineering and Technology (TJET)
The ‘TRAP - TRuss Analysis Program’ can assist engineers in the analysis of plane truss-type structures, as well as prove an excellent basis for understanding the “finite – element” method. The Program is completely menu-driven, with all nodes, elements, and load data entered through an input file. TRAP includes plotting for displaying the truss geometry in its original shape showing all nodes and support points. In the analysis process, firstly the structure data; e.g number of nodes, elements, materials and supports are to be defined. Secondly, element properties and support constraints have to be specified. Finally, nodal global loads are …
Optimal Utilization Of Timber Poles As Structural Members Of Formwork, Ladislaus Lwambuka
Optimal Utilization Of Timber Poles As Structural Members Of Formwork, Ladislaus Lwambuka
Tanzania Journal of Engineering and Technology (TJET)
Timber poles of the type “Mirunda” are commonly used in East Africa as formwork support structures for casting of reinforced concrete slabs, beams and canopies. It is also widely known that the “Mirunda” poles as structural members of formwork are massively used without any structural consideration and guidance. This common practice has resulted into wastage of natural resources and escalated construction costs. This study has attempted to establish the load bearing capacity of randomly selected “Mirunda” poles through laboratory testing. Using an existing construction site as a case study, the results have been used to establish the actual number of …