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Articles 31 - 60 of 88
Full-Text Articles in Engineering Science and Materials
Aquaculture In Hydropower Reservoirs, Racheal Macharia
Aquaculture In Hydropower Reservoirs, Racheal Macharia
Tanzania Journal of Engineering and Technology (TJET)
There is an undoubtedly existing relationship between water, energy, and food and their interaction with the natural environment and mankind. Climate change is the talk of the day in global development discussions as it intensifies water shortages, energy, poverty, food shortages, and environmental degradation. Currently, most of the hydropower dams constructed in Africa are majorly built to store water for agricultural purposes, control flooding, and generate electricity. Notable projects include the seven forks hydropower stations located on the Tana River in Kenya; Aswan high dam in Egypt; Grand Renaissance dam in Ethiopia; Kariba dam in Zimbabwe and Akosombo in Ghana. …
The Fourth Industrial Revolution: Opportunities And Challenges To The Future Of Mechanical Engineering, Ulingeta O.L. Mbamba
The Fourth Industrial Revolution: Opportunities And Challenges To The Future Of Mechanical Engineering, Ulingeta O.L. Mbamba
Tanzania Journal of Engineering and Technology (TJET)
This paper provides a conceptual overview of the developments of the Fourth Industrial Revolution (4IR) and derives challenges and opportunities for the future of the mechanical engineering profession. The paper broadly defines 4IR as the fusion of technologies and interaction across physical, digital and biological aspects, while defining mechanical engineering as "a multi-faceted discipline that encompasses the teaching, practice and guidance of others in the development and application of scientific principles to mechanical systems". The paper looks specifically at developments in the Internet of Things (IoT), blockchain technology, robotics, Big Data analytics, biotechnology, nanotechnology, 3D printing and artificial intelligence and …
Designing And Manufacturing Of Vegetable Slicing Machine, Juma Nuhu Msuya
Designing And Manufacturing Of Vegetable Slicing Machine, Juma Nuhu Msuya
Tanzania Journal of Engineering and Technology (TJET)
Agro-processing industry is faced with a challenge of slicing of vegetables for immediate consumption. This stems from the fact that the traditional slicing methods use bare hands, and knives. This method is faced with shortcomings of inefficiency, poor hygiene, and significant dangers to injury. If vegetables are not sliced, their drying takes longer, may possibly be spoiled, and cannot be stored for future uses. Therefore, this paper strives to design a vegetable slicing machine to increase the efficiency of the drying process as a post-processing step. The study employed a Pugh’s design model to design the machine and manufacture it. …
Machine Learning Approach For Classifying Power Outage In Secondary Electric Distribution Network, Stephan Mgaya, Hellen Maziku
Machine Learning Approach For Classifying Power Outage In Secondary Electric Distribution Network, Stephan Mgaya, Hellen Maziku
Tanzania Journal of Engineering and Technology (TJET)
Power outage is the problem that hinders social and economic development especially for developing countries like Tanzania. Frequent power outages damage electric equipment, and negatively affect the industrial production process. Power outages cannot be completely eradicated due to uncontrolled cause like natural calamities but technical challenges can be managed and hence reducing power outages. The existing manual methods used to locate power outage like customer calls is inefficient and time consuming. On the other hand, modern method like the Advanced Metering Infrastructure (AMI) still faces a challenge in effectively classifying power line outage due to the nature of imbalanced datasets. …
An Iot Based Worker Safety Helmet Using Cloud Computing Technology, Yuthriya Iddi Khamis, Mahmoud Alawi, Waheed Muhammad Sanya
An Iot Based Worker Safety Helmet Using Cloud Computing Technology, Yuthriya Iddi Khamis, Mahmoud Alawi, Waheed Muhammad Sanya
Tanzania Journal of Engineering and Technology (TJET)
Miner safety and security is a major challenge around the world due to the exposure to toxic gases that are frequently released in underground mines. Miners' health is adversely affected primarily by toxic gases, which endanger the workers' lives. Furthermore, human sensory abilities do not detect these dangerous gases. As a result, this paper proposes a safety monitoring system that includes a temperature sensor, humidity sensor, and gas sensors to detect harmful gases and alert miners to those harmful gases using the smart helmet they wear. These gases are transmitted to the control station via the cloud using Internet of …
Real-Time Data Analytics For Monitoring Electricity Consumption Using Iot Technology, Waheed Muhammad Sanya, Gaurav Bajpai, Omar Haji Kombo, Evariste Twahirwa
Real-Time Data Analytics For Monitoring Electricity Consumption Using Iot Technology, Waheed Muhammad Sanya, Gaurav Bajpai, Omar Haji Kombo, Evariste Twahirwa
Tanzania Journal of Engineering and Technology (TJET)
Rising electricity bills as a result of climate variability and new home electrical and electronic appliances are becoming a major source of concern for most end users. Consumers are typically unaware of their household electricity consumption patterns and the costs associated with them, making proper planning and budgeting difficult. Monitoring and controlling energy consumption on appliances can reduce energy costs for end-users. The Internet of Things (IoT) has the potential to provide remote monitoring and control of devices via automated monitoring and control. In this study, we propose an IoT-enabled system for monitoring and controlling energy consumption in homes to …
Group-Based Data Offloading Techniques Assisted By D2d Communication In 5g Mobile Network, Juma S Ally
Group-Based Data Offloading Techniques Assisted By D2d Communication In 5g Mobile Network, Juma S Ally
Tanzania Journal of Engineering and Technology (TJET)
Machine type communication devices proposed as one of the substantial data collections in the 5G of wireless networks. However, the existing mobile communication network is not designed to handle massive access from the MTC devices instead of human type communication. In this context, we propose the device-to-device communication assisted a mobile terminal (smartphone) on data computing, focusing on data generated from a correlated source of machine type communication devices. We consider the scenario that the MTC devices after collecting the data will transmit to a smartphone for computing. With the limitation of computing resources at the smartphone, some data are …
Assessment Of Energy Efficiency In Beverage Industry, Mahamudu H. Mtebwa
Assessment Of Energy Efficiency In Beverage Industry, Mahamudu H. Mtebwa
Tanzania Journal of Engineering and Technology (TJET)
The brewery industry has a significant contribution to the national income. However, it is also associated with energy intensive processes and pollution. In this work, the energy efficiency assessment of the largest brewery in Tanzania i.e., Tanzania Breweries Limited has been conducted. Energy consumption analysis was conducted according to IEEE SA 739 1995. Important parameters used to assess brewery energy efficiency were boiler efficiency and losses, equipment energy productivity as well as load factor. It was found that the main energy consumers are packaging (54.63%), brewing (29.30%) and utilities (15.17%). More importantly, it was found that about 68% of the …
A Model For Sustainable Adoption Of Solar Photovoltaic Technology In Tanzania, Joseph Kihedu
A Model For Sustainable Adoption Of Solar Photovoltaic Technology In Tanzania, Joseph Kihedu
Tanzania Journal of Engineering and Technology (TJET)
The aim of the study was to develop a sustainable model for enhancement of the solar PV technology adoption in Tanzania. The model was developed based on the identified barriers that hinder the adoption of solar PV technology and adopted the best strategies from successful projects. Further, the drivers and activities were developed based on selected best strategies from successful projects. The identified barriers to the adoption of solar PV technology, which are grouped into five associated categories and their significances, are lack of access to finance (32%), non-enforcement of policy and regulation (31%), technical (18%), lack of awareness (9%) …
Production Of Paper Pulp Using Sisal Fiber Waste From Sisal Spinning Processes, Ekael Mbise
Production Of Paper Pulp Using Sisal Fiber Waste From Sisal Spinning Processes, Ekael Mbise
Tanzania Journal of Engineering and Technology (TJET)
Disposal of large volumes of textile waste is an escalating problem for textile industries. Sisal spinning industry is the one of the textile industries releasing large volumes of textile waste in the landfills. The rising costs, and reduction of available space together with increasing stringent environmental measures are making burying and land filling of textile waste, a declining option. This study therefore explores recycling options where the potential of using sisal fiber waste produced during sisal spinning processes as raw materials for the production of paper pulp was investigated. Sampling was done at 21stCentury Holdings Limited allocated at Chang’ombe industrial …
Cyber Security Challenges, Its Emerging Trends On Latest Information And Communication Technology And Cyber Crime In Mobile Money Transaction Services, Hakeem J. Pallangyo
Cyber Security Challenges, Its Emerging Trends On Latest Information And Communication Technology And Cyber Crime In Mobile Money Transaction Services, Hakeem J. Pallangyo
Tanzania Journal of Engineering and Technology (TJET)
This paper investigates the challenges emerging trends on latest Information and Communication Technology and cybercrime in mobile money transaction services in Tanzania. The objective of this is to evaluate the challenges associated with this rapid growth in ICT and to determine factors influencing Cybersecurity readiness and Cybercrimes in mobile money transaction services. Cyber Security plays a significant role in the field of Information and Communication Technology especially on mobile money transaction services. The study recognizes the provision of mobile money services by both telecommunication companies and local banks, the fact is that whenever we think about the cyber security, the …
Resilient Modulus Of Siliciclastic Unbound Granular Materials Under Repeated Wheel Loading, Siya Rimoyi
Resilient Modulus Of Siliciclastic Unbound Granular Materials Under Repeated Wheel Loading, Siya Rimoyi
Tanzania Journal of Engineering and Technology (TJET)
The Resilient Modulus (Mr) is a fundamental material property input in modern Mechanistic-Empirical (M-E) pavements structural design. Empirical pavement design methods have been in use over a long period during which large databases of four- days-soaked California Bearing Ratio (CBR) values at or near the Maximum Dry Density have been generated in the strength assessments for Unbound Granular Materials (UGMs). In the adoption of the M-E design approach researchers have so far attempted with various degrees of success to develop models to derive resilient modulus from the conventional CBR-based databases. This study provides an extensive laboratory experimental study to investigate …
Development Of Intensity-Duration-Frequency (Idf) Models For Manually Operated Rain Gauge Catchment: A Case Study Of Port Harcourt Metropolis Using 50 Years Rainfall Data, Francis Ogbozige
Tanzania Journal of Engineering and Technology (TJET)
Hydraulic structures such as surface drainages and culverts are usually constructed in urban areas with the intention of draining runoff into nearby streams and rivers in order to avoid flooding. However, most of these structures frequently fail to serve the intended use due to the occurrence of high intensity rainfall accompanied with long duration, which produce runoff discharge higher than their designed capacities. This is common in many developing countries as drainages and culverts are most times constructed without considering hydrological analysis of the catchment. Hence, this research considered Port Harcourt city as a case study by utilizing 50 years …
Real-Time Complex Hand Gestures Recognition Based On Multi- Dimensional Features, Isack Bulugu
Real-Time Complex Hand Gestures Recognition Based On Multi- Dimensional Features, Isack Bulugu
Tanzania Journal of Engineering and Technology (TJET)
Gesture recognition is broadly utilized within the field of sensing. There are basically three gesture recognition methods based on computer vision, depth sensor and motion sensor. Motion sensor-based gesture recognition has few input data, fast speed, and direct access to three- dimensional information of the hand. The advantages of traditional motion sensor-based gesture recognition have gradually become a current research hotspot. The essence of traditional motion sensor-based gesture recognition is a pattern recognition problem, and its accuracy depends heavily on the feature dataset extracted from prior experience. Unlike traditional pattern recognition methods, deep learning can be used to a large …
Complete Neighbourhood Search Heuristic Algorithm For Portfolio Optimization, Collether John
Complete Neighbourhood Search Heuristic Algorithm For Portfolio Optimization, Collether John
Tanzania Journal of Engineering and Technology (TJET)
In portfolio optimization, the fundamental goal of an investor is to optimally allocate investments between different assets. Mean-variance optimization methods make unrealistic assumptions to solve the problem of optimal allocation. On the other hand, when realistic constraints like holding size and cardinality are introduced it leads to optimal asset allocation which differ from the mean variance optimization. The resulting optimization problem become quite complex as it exhibits multiple local extrema and discontinuities. Heuristic algorithms work well for the complex problem. Therefore, a heuristic algorithm is developed which is based on hill climbing complete (HC-C). It is utilized to solve the …
Performance Of Calcium Chloride- Ammonia Adsorption Refrigeration System, Michael John
Performance Of Calcium Chloride- Ammonia Adsorption Refrigeration System, Michael John
Tanzania Journal of Engineering and Technology (TJET)
An experimental study on the performance of calcium chloride-ammonia adsorption system is described. A single bed water cooled condenser adsorption refrigerator prototype, which utilises calcium chloride-ammonia pair has been developed and tested in the laboratory. Experiments have been conducted for desorption temperatures of 100 °C with desorption time varying from 1 to 4 hours. An electric tape heater and a timer were used to perform the experiments. The adsorption temperature profile, adsorption rate and prototype performance have been analysed and discussed. The tested heating and desorption temperature of 100 °C and heating and desorption time of 1 to 4 hours …
Assessment Of The Impacts Of Climate Variability On Hydropower Generation: A Case Study Of The New Pangani Falls, Tanzania, Dativa Byarufu
Assessment Of The Impacts Of Climate Variability On Hydropower Generation: A Case Study Of The New Pangani Falls, Tanzania, Dativa Byarufu
Tanzania Journal of Engineering and Technology (TJET)
Climate change poses potential impacts on hydropower generation either positively by increasing or negatively by decreasing river flow. This study assessed the impacts of climate variability on hydropower with a focus on the New Pangani Falls in Tanzania. Rainfall and temperature time series data from 1980-2014 were analyzed in relation to river discharge and associated impacts to hydropower generation. The Man-Kendall test was used to detect trend in both annual and seasonal time series. The results showed a negative trend in annual rainfall with Z= -2.41 at α = 0.05 and the slope Q = -0.964. Seasonal trend analysis showed …
The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1
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 …
Influence Of Tempering And Cryogenic Treatment On Retained Austenite And Residual Stresses In Carbonitrided 18crnimo7-6 Low Alloy Steel, Richard Katemi
Influence Of Tempering And Cryogenic Treatment On Retained Austenite And Residual Stresses In Carbonitrided 18crnimo7-6 Low Alloy Steel, Richard Katemi
Tanzania Journal of Engineering and Technology (TJET)
This work investigated the influence of tempering conditions coupled with cryogenic treatment on thermal stabilization of retained austenite and residual stress distributions in carbonitrided 18CrNiMo76 low alloy steel samples. The carbonitriding conditions were set to enable attaining surface carbon and nitrogen content of 0.87 and 0.34 mass.-percent respectively. After carbonitriding, some of the samples were subjected to varying tempering conditions followed by cryogenic treatment at-120 °C using nitrogen gas. Analysis of both retained austenite and residual stresses was conducted using X-ray diffraction. In the as-quenched state, carbonitrided samples contained 52 mass.-percent. Samples that were directly subjected to the cryogenic treatment …
Moisture Induced Deformations In Glulam Members - Experiments And 3-D Finite Element Model, Henry Meleki Kiwelu
Moisture Induced Deformations In Glulam Members - Experiments And 3-D Finite Element Model, Henry Meleki Kiwelu
Tanzania Journal of Engineering and Technology (TJET)
Experiments were performed on scaled glue laminated bending specimens to observe time dependent development of deformations during drying and wetting. Measurements determined changes in the average moisture content and external shape and dimensions between when specimens were placed into constant or variable climates. Alterations in the external shape and dimensions reflected changes in the average value and distribution of moisture and mechanosorptive creep in the glulam. The results are being used to develop a sequentially-coupled three-dimensional hygrothermal Finite Element (FE) model for predicting temporally varying internal strains and external deformations of drying or wetting solid wood structural components. The model …
Handling Of Syringe Sharps In A Non-Incineration Health Care Waste Disposal, Tito Mwinuka
Handling Of Syringe Sharps In A Non-Incineration Health Care Waste Disposal, Tito Mwinuka
Tanzania Journal of Engineering and Technology (TJET)
An attempt has been made by the R&D team of the University of Dar es Salaam to design and manufacture two needle cutter prototypes, a manually operated and an automatic needle cutter to be used in rural and urban areas, respectively. This is part of the UNDP and WHO efforts aimed at promoting the non-burn medical waste disposal technologies in developing countries such as Argentina, India, Latvia, Lebanon, Philippines, Senegal, Tanzania and Vietnam. The project also involves designing and manufacturing of the autoclaves for sterilizing of needle cutters and other infectious medical waste. The use of needle cutters in hospitals …
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 …
Case Studies: In-Situ Rebuilding Of Damaged Rope Drum Shafts Of Ssg Crane And The Repair Of Circumferential Crack Of Cement Kiln By Welding, Joseph Runyoro
Case Studies: In-Situ Rebuilding Of Damaged Rope Drum Shafts Of Ssg Crane And The Repair Of Circumferential Crack Of Cement Kiln By Welding, Joseph Runyoro
Tanzania Journal of Engineering and Technology (TJET)
Material failures in engineering are characterized by unwanted downtime of equipment and require the application of sound engineering principles to rectify the problem so that it does not reoccur. The most widely method for repairing damaged steel structures such as rope drum shaft or cracked cement kiln is by Manual metal arc welding. The equipment mentioned have their main importance that, when they are broken down, they cost a lot of money in lost revenue and affects a lot of people in terms of business and livelihood. The nominal diameter (DN) 240 rope drum shaft was damaged when the roller …
Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor
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
Tanzania Journal of Engineering and Technology (TJET)
No abstract provided.
Discrete Element Modelling Of The Abrasive Dehulling Process Of Sorghum And Millet, E. L. Lazaro
Discrete Element Modelling Of The Abrasive Dehulling Process Of Sorghum And Millet, E. L. Lazaro
Tanzania Journal of Engineering and Technology (TJET)
The abrasive dehulling process of sorghum and millet was modelled using a three-dimensional discrete element model. The model was validated by comparison between experimental and simulation results. Good correlation between experimental and simulation results was obtained. Several numerical experiments were also carried out using the developed model to investigate the influence of mill and grain parameters on dehulling of sorghum and millet. The simulated results correlated well with experimental results from literature. The developed model therefore provides a simple and cheap tool, which can be used to study the dehulling process in more detail than, is currently possible using the …
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
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 …
A Fracture Kinetics Analysis Of Hydrogen Embrwi'lement, J Mshana
A Fracture Kinetics Analysis Of Hydrogen Embrwi'lement, J Mshana
Tanzania Journal of Engineering and Technology (TJET)
In studies on stress corrosion cracking caused by hydrogen embrittlement of metals, it has been observed that within the high remperature range rhe Armenius activation energy is negative. This is quite unusual Since ther- mall)' activated crack g.'vwth processes are controlled by positive appar- ent activation energy. The unders/auding of this effect is of inleavst to design and maintenance engineers. The study demonstrates, with a syn- thesis method, a physically rigorous and rational kinetics Of thermally activated processes of some aspects ofenvironment assisted crack growth. It is show that the observed crack growth behavior may be described by single barrier …
Model For Complete Drawdown Of Floating Solids In Stirred Tank Reactors, J Mmbaga
Model For Complete Drawdown Of Floating Solids In Stirred Tank Reactors, J Mmbaga
Tanzania Journal of Engineering and Technology (TJET)
A Semi-empirical model has been developed on the basis of Kolmogoroff's theory of isotropic turbulence to determine the minimum drawdown speed for floating solids in a mechanically agitated vessel. An adjustable pa- rameter in the model is found to be afunction of impeller type and position in a vessel. A simplified representation of macroscopicflow pattern, rep- resenting the circulation flow in a vessel depending on impeller pumping characteristic is developed to account for recirculation pattern.