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Tanzania Journal of Engineering and Technology (TJET)

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Articles 61 - 86 of 86

Full-Text Articles in Energy Systems

Fermentability Of Concentrated Sulfuric Acid Hydrolyzates From Aspenwood And Pinewood, Kando Janga Dec 2020

Fermentability Of Concentrated Sulfuric Acid Hydrolyzates From Aspenwood And Pinewood, Kando Janga

Tanzania Journal of Engineering and Technology (TJET)

The fermentability of hydrolyzates derived from two-stage concentrated sulfuric acid hydrolysis of Trembling aspen (Populus tremula) and Scots pine (Pinus sylvestris) were investigated. Three types of hydrolyzates were produced at mild, moderate and high decrystallization severity conditions. Portions of each of the original hydrolyzates were concentrated by vacuum evaporation to increase the sugar fraction to simulate industrial applications. Both sets of hydrolyzates were fermented anaerobically using Saccharomyces cerevisiae ATCC 96581. After 23 hours of fermentation, complete glucose consumption was observed for all the original hydrolyzates, with no signs of inhibition. The ethanol yields from these hydrolyzates ranged from 68% to …


Analysis Of Performance Characteristics Predicted From Several Experimental Data And Conversion Methods For Pumps As Turbine Application Using Statistical Techniques, Ombeni J. Mdee Dec 2020

Analysis Of Performance Characteristics Predicted From Several Experimental Data And Conversion Methods For Pumps As Turbine Application Using Statistical Techniques, Ombeni J. Mdee

Tanzania Journal of Engineering and Technology (TJET)

Different performance characteristics have been indicated when running centrifugal pumps in the reverse direction. The water flows from the discharge side of the pump to the suction side to run in the reverse direction and generate the mechanical rotational energy for the micro-hydropower plant. The current study evaluates the extent of variation of performance characteristics predicted by several experimental data from different pump-specific speeds and conversion methods. The performance characteristics discussed include the head, flow rate, efficiency and specific speed. The flow rate and head of a pump operating in pump mode divided with the characteristic of the pump operating …


Potential For Increased Rural Electrification Rate In Sub-Saharan Africa Using Swer Power Distribution Networks, Aviti Thadei Mushi Dec 2020

Potential For Increased Rural Electrification Rate In Sub-Saharan Africa Using Swer Power Distribution Networks, Aviti Thadei Mushi

Tanzania Journal of Engineering and Technology (TJET)

Rural electrification rate (RER) in Africa is still low to date. Several countries in Sub-Saharan Africa have tried to address this problem using conventional single phase two-wire or three-phase three-wire systems, however at large costs due to the nature of dispersed rural load centres, low load demand, and low population density. Another solution of off-grid generation creates associated health problems. Therefore, this paper undertakes a review of a single wire earth return (SWER) network as a RER improvement solution. The paper undertakes intensive literature review to elucidate challenges and solutions to the implementation of SWER technology. Advantages of SWER technology …


Wind Power Integration And Its Impact On Power Quality-A Didactic Approach, Santos Kihwele Dr Dec 2020

Wind Power Integration And Its Impact On Power Quality-A Didactic Approach, Santos Kihwele Dr

Tanzania Journal of Engineering and Technology (TJET)

This paper presents a model of a wind power system integrated with realistic power system, with intention of using it in addressing power quality issues in relations to grid codes during steady-state operation transient-state operation i.e., presence of grid fault events. For that case, a didactic approach of the normal performance of power systems due to the connection of fixed-speed wind turbine with induction generators is used. A study of integrating wind farms will be presented, including the incidence of high inrush current due to switching capacitor banks, out-rush current and voltage sags due to nearby three phase faults. As …


Performance Analysis Of Renewable Energy Resources In Rural Areas: A Case Study Of Solar Energy, Jackson Justo Jun 2020

Performance Analysis Of Renewable Energy Resources In Rural Areas: A Case Study Of Solar Energy, Jackson Justo

Tanzania Journal of Engineering and Technology (TJET)

This paper presents an overview of the recent development trends of solar photovoltaic (PV) systems and the performance in the Tanzanian context. The two types of solar power generation that are considered in this paper are: i) solar PV systems and ii) concentrated solar power (CSP). The two are compared in terms of cost of energy and energy storage mechanism. Moreover, the effect of ambient temperature on the solar PV module is analyzed. In addition, a detailed analysis on using solar axis tracking to increase the power generation is also presented. The extent to which the cell surface temperature and …


Modeling And Control Of Solar Pv With Battery Energy Storage For Rural Electrification, Irene Masenge Jun 2020

Modeling And Control Of Solar Pv With Battery Energy Storage For Rural Electrification, Irene Masenge

Tanzania Journal of Engineering and Technology (TJET)

In rural areas where electric power grid network is rarely available, power generation from renewable energy resource such as solar photovoltaic (PV) is mostly accomplished in standalone mode. The standalone solar PV system requires energy storage device to achieve reliable power supply to the end users. This paper presents modelling and coordination control of solar PV with battery energy storage system (BESS) for rural-electrification applications. The proposed control is accomplished via a bidirectional buck-boost converter with the objective of maintaining voltage at the DC bus constant. Simulation results based-on MATLAB/Simulink platform confirms good performance of the proposed system


The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1 Dec 2019

The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1

Tanzania Journal of Engineering and Technology (TJET)

Worldwide, every day human beings generate millions of tons of Faecal Sludge (FS), which is rich in water, nutrients, energy, and organic compounds. Yet FS is not being managed in a way that permits us to derive value from its reuse, while at the same time, millions of farmers struggle with depleted soils and lack of water. In most of the developing countries, energy for cooking is mainly derived from cutting of trees, either as wood or charcoal. Resource recovery and reuse from FS can create livelihoods, enhance food security, support green economies, reduce waste and contribute to cost recovery …


Potential Use Of High Rate Algae Ponds For Resource Recovery In The Water-Food-Energy Nexus For Tanzania: A Review, Mary Kayombo Jun 2019

Potential Use Of High Rate Algae Ponds For Resource Recovery In The Water-Food-Energy Nexus For Tanzania: A Review, Mary Kayombo

Tanzania Journal of Engineering and Technology (TJET)

The use of High Rate Algal Ponds (HRAPs) for the treatment of wastewater and resource recovery has raised interest in recent years. Treatment of wastewater through this technology has proved to have high efficiency in reducing the level of pollution, nutrients, dissolved solids as well as pathogens. HRAPs are more efficient than conventional Wastewater Stabilization Ponds (WSPs) due to their design approach that provides room for high rate bio-chemical processes, which increase the mechanisms of nutrients and pathogens removal as well as the rate of micro-algae production for purposes of resource recovery. This paper reviews the upgrading potential of existing …


The Comparative Analysis Of The Performances Of Four And Six Pole Pairs Permanent Magnet Synchronous Generator, Ra Msuya Jun 2019

The Comparative Analysis Of The Performances Of Four And Six Pole Pairs Permanent Magnet Synchronous Generator, Ra Msuya

Tanzania Journal of Engineering and Technology (TJET)

Wind power applications using multi-poles permanent magnet generators have become very attractive especially in small ratings. Low-speed multi-pole PM generators are maintenance-free and may be used in different climate conditions. Most of the low speed wind turbine generators presented is permanent magnet machines, which have advantages of high efficiency and reliability since there is no need of external excitation and conductor losses are removed from the rotor. From the study two types of PM AC generator are designed with 6 pole pairs and the other one with 4 pole pairs. These generators were designed and analysed using Maxwell software. The …


Low Voltage Ride Through Enhancement For Wind Turbines Equipped With Dfig Under Symmetrical Grid Faults, Francis Mwasilu Jun 2018

Low Voltage Ride Through Enhancement For Wind Turbines Equipped With Dfig Under Symmetrical Grid Faults, Francis Mwasilu

Tanzania Journal of Engineering and Technology (TJET)

In modern power systems with significant penetration of wind-turbines (WTs), improvement of low voltage ride through (LVRT) capability of WTs equipped with doubly-fed induction generators (DFIGs) is an important issue. Thus, this paper proposes a low voltage ride through (LVRT) strategy, which comprise of a capacitor connected in series with an inductor both connected in parallel to a resistor. The configuration is then connected to a small series resistor via a pair of antiparallel-Thyristors. The circuit and its switching control scheme of the proposed LVRT circuit are designed to: minimize the transition times, maintain the RSC connection to the rotor-windings, …


Effects Of Methyl-Blue Addition In Sewage Substrate On The Performance Of Microbial Fuel Cell, Joseph H. Kihedu Dr. Jun 2018

Effects Of Methyl-Blue Addition In Sewage Substrate On The Performance Of Microbial Fuel Cell, Joseph H. Kihedu Dr.

Tanzania Journal of Engineering and Technology (TJET)

Experimental study was undertaken to evaluate performance of microbial fuel cell. Without addition of methyl blue, the cell generated 1.265 V, 0.403 mA and 56.12 mW/m2 after three hours of operation. With 300 µM methyl blue in sewage anolyte, 6.7% increase in voltage, 20.5% increase in current and 28.6% increase in power density was observed. By using ash water catholyte, addition of methyl blue in anolyte led to increase of 9.0% in voltage, 38.5% in current and 50.9% for power density. Between three and twenty four hours of continuous operation of the cell with phosphate buffer catholyte, the average voltage …


Design And Manufacture Of A Waste Compactor Prototype: A Step Towards Implementing A Non-Burn Health Care Waste Disposal In Developing Countries, Tito Mwinuka Jun 2017

Design And Manufacture Of A Waste Compactor Prototype: A Step Towards Implementing A Non-Burn Health Care Waste Disposal In Developing Countries, Tito Mwinuka

Tanzania Journal of Engineering and Technology (TJET)

Non-burn technology is the only safe way of handling and disposing infectious healthcare waste. It involves steam treatment of infectious waste at temperatures higher than 121 o C for a minimum of 30 minutes before disposing them just like other municipal waste. Infectious healthcare waste is normally only about 10 25% of all healthcare waste. In this paper, design, manufacturing and testing of a waste compactor for reducing waste volume to facilitate its handling is discussed. Preliminary tests show that the waste volume can be reduced to less than 10% of its original volume using the developed compactor. Waste compactors …


Loss Modeling Of A Permanent Magnet Dc Motor Drive Water Pumping System, Nelson Lujara Dec 2014

Loss Modeling Of A Permanent Magnet Dc Motor Drive Water Pumping System, Nelson Lujara

Tanzania Journal of Engineering and Technology (TJET)

The paper presents an analytical approach to the determination of losses in each of the sub-systems of the Photovoltaic (PV) Permanent Magnet DC Motor (PMDC) drive water pumping system with and without maximum power tracking. The losses of the system at varying heads are firstly, determined using parameters from the data sheets and then validated by experimental results. The results are used to establish the head and the flow rate optimal operating point of the system.


Analysis Of Different Techniques For Improving Performance Of Flat Plate Solar Collectors For Fruits Drying, Godfrey Mbabaye Jun 2014

Analysis Of Different Techniques For Improving Performance Of Flat Plate Solar Collectors For Fruits Drying, Godfrey Mbabaye

Tanzania Journal of Engineering and Technology (TJET)

Fruits drying had become a broader technology in fruits and vegetables value addition. The technology is reported to be a promising way of drying without incurring higher cost but its adaptation has not been feasible in rural areas. Solar dryers have been developed but its poor performance limits its applicability. In this study, several techniques for modifications of traditional solar collector were addressed. It was observed that, varying collector designs in different techniques, a range of collector performances can be archived. The research shows that, collector efficiency can be improved by 9.6% when employing double duct counter flow compared to …


Thermolysis And Kinetics Of Scrap Tyre And Bagasse For Energy Utilization, Petro Ndalila Dec 2013

Thermolysis And Kinetics Of Scrap Tyre And Bagasse For Energy Utilization, Petro Ndalila

Tanzania Journal of Engineering and Technology (TJET)

The increase of energy demand has brought concern to find alternative fuel that will at least sustain the requirement. Bagasse and scrap tyre are waste generated in our industrial activities, which can be used in energy production to subsidize the demand. This paper, aim to study the decomposition behaviour and kinetics of biomass (bagasse) and scrap tyre as preliminary stage of fuel sample analysis to be considered for energy production in gasification/combustion or pyrolysis facilities. The behaviour demonstrated with thermogravimetric analyzer (TGA), shows that all samples have high volatile amount release, 84.21% for bagasse and 85.08% for scrap tyre, which …


Analysis Of Power Efficiency Of A Direct-Driven Locally Fabricated Permanent Magnet Ac Generator For Small-Scale Wind Power Applications In Tanzania, Mussa Iddi Mgwatu Dr. Dec 2013

Analysis Of Power Efficiency Of A Direct-Driven Locally Fabricated Permanent Magnet Ac Generator For Small-Scale Wind Power Applications In Tanzania, Mussa Iddi Mgwatu Dr.

Tanzania Journal of Engineering and Technology (TJET)

The use of direct-driven permanent magnet alternating current (AC) generators offers the opportunity to reduced costs and increased system efficiency. This type of generator could be the best alternative for rural population whom are not connected to the national grid. To improve the design and efficiency of locally fabricated generators, it is imperative to characterize both their mechanical and electrical parameters. This paper presents the analysis of power efficiency of the synchronous permanent AC generator locally fabricated in Tanzania. In this case, load resistance and rotational speed are characterized using designed experiment. The output current and voltage of the generator …


Improvement Of Hydraulic Press For Vegetable Oil Expression In Rural Areas, I. P. Bateebe Jun 2013

Improvement Of Hydraulic Press For Vegetable Oil Expression In Rural Areas, I. P. Bateebe

Tanzania Journal of Engineering and Technology (TJET)

Cultivation of oil producing crops especially Jatropha and croton as source of vegetable oil for biodiesel production is being encouraged in rural areas. To recover oil from seed, manual press is the feasible method in rural areas where there is no electricity. Research was conducted to improve hydraulic oil press machine for rural application. Factors affecting oil recovery were found to be: moisture content of seeds, operating pressure, seed oil content, and the amount of seeds pressed per batch. Percentage oil recovery was improved by reducing diameter of press cylinder, hence increasing expression pressure, and either reducing amount of seed …


Development Of Pilot Plant For Bio-Ethanol Processing, Emrod Elisante Jun 2010

Development Of Pilot Plant For Bio-Ethanol Processing, Emrod Elisante

Tanzania Journal of Engineering and Technology (TJET)

The paper outlines achievements obtained in developing a pilot bio-ethanol plant at the Department of Chemical and Mining Engineering (CME), University of Dar es Salaam. The pilot plant consists of: 30 L inoculums tank; 1,700 L fermenter; 1,500 L/day distillation column; and ancillary equipment. The prototype is a platform intended to be used for technology demonstration and research by graduate and undergraduate students studying the production of bio-ethanol using traditional and non-traditional raw materials like coffee mash, cashew fruit, and sisal inulin. The equipment has been developed using locally available engineering resources and the distillation column with 18 sieve tray …


Development Of A Genetic Algorithm Based Search Strategy Suited For Design Optimisation Of Internal Combustion Engines, Nalitolela G Jun 2008

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 …


Accuracy Analysis For Kolmogorov Entropy Used In Studying The Chaotic Dynamics Of Cfb Reactors Based On Solids Concentration Fluctuations, Samwel V. Manyele Jun 2008

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 …


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 …


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.


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 …


Solar Heater For Curing Tobacco Part I: Overview And Theory, J John Dec 1994

Solar Heater For Curing Tobacco Part I: Overview And Theory, J John

Tanzania Journal of Engineering and Technology (TJET)

This is two parl paper. In part one of the papet; an overview on the use Of packed beds on heat collectors To be used in natural convection systems is presented. A brief theoretical background and literature review has also been presented. Theoretical analysis and performance equations are pre- sented in detail. Two zypes of absorbers are proposed for investigation. The firs,' one will be with flow below the absorber and the other with flow "'through " {he absorber. These shall be compared with the conventional flat plate collector. For comparing the performance, packings of different materials, shapes, and sizes …


Energy Considerations In Tanzania, A Makange Dec 1979

Energy Considerations In Tanzania, A Makange

Tanzania Journal of Engineering and Technology (TJET)

During the assessment of the manuscript, it was observed that the paper does not include an abstract. The document proceeds directry to the main content without providing a separate abstract that summarize the study's objectives, methodology, key findings and conclusions


Windmill Installations In Tanzania, R Reichel Dec 1979

Windmill Installations In Tanzania, R Reichel

Tanzania Journal of Engineering and Technology (TJET)

During the assessment of the manuscript, it was observed that the paper does not include an abstract. The document proceeds directry to the main content without providing a separate abstract that summarize the study's objectives, methodology, key findings and conclusions