Tanzania Journal of Engineering and Technology

Strategies for Overcoming Product Certification Challenges Faced by Food Manufacturing Small and Medium Enterprises in Tanzania

2025-06-11T14:27:12+00:00

Prospects of Clean Cooking Energy in Africa - Transition Pathways and Implications

2025-06-11T14:40:11+00:00

Despite abundant renewable energy resources, African countries still suffer from energy poverty, particularly in cooking. Up to 2022, about 74% of the African population had no access to clean cooking energy. With focus to Sub-Saharan African population, 90% has no access to clean cooking energy which decrease by 7% when kerosene is included. Traditional cooking, which involves the use of charcoal and firewood, is associated with health problems, environmental degradation, socioeconomic issues, and gender inequality. Transitioning to clean cooking energy not only promises significant health benefits but also offers opportunities for sustainable economic development and environmental preservation. In this study, the desk research method was used, which involved compiling raw published data such as research articles, government reports, implemented project reports, and published statistics. The following are the findings of this study: Firstly, for the improvement of health, environment, and social economic issues, the community must transition from traditional cooking to clean cooking. Secondly, despite the promises posed by energy transition, upfront cost and technological challenges remain to be a challenge that need action. Thirdly, the government should weigh up on clean cooking technologies investment, program sustainability, and engaging the community. Lastly, the government should structure the clean cooking agenda based on the resource’s proportionality in the region. Generally, to improve the welfare of the community, energy transition from traditional to clean cooking stands as the main piece, however, the government should intentionally intervene for the transition to be realized.

Analysis of an Improved Reliability Dual-Buck Structured Three-Level Flying Capacitor Inverter

2025-06-11T15:25:12+00:00

With the increased demand for high-reliability power converters in the electric drive-train and propulsion systems, the efforts to design and analyze converters with high fault tolerance have become apparent. Among the emerging trends to improve the reliability of power converters is the incorporation of dual-buck (DB) structures in traditional converter topologies. Thus, this paper studies a singlephase dual-buck structured three-level flying capacitor (FC) inverter. The dual-buck flying capacitor (DBFC) inverter was constructed in such a way as to suppress the shoot-through problems that may occur because of the switching mismatch and gate driver delay, as exhibited in the traditional FC inverter. The detailed operation of the DBFC inverter was performed using a comparative analysis of the traditional FC inverter as a benchmark. It was noted that the DBFC inverter considerably reduces the current stress on some switches and mitigates the shoot-through problem. Moreover, it was inferred that apart from improving the reliability of the inverter, the DBFC inverter reduces the total harmonic distortion (THD) of the output current. The 98.8% maximum efficiency and 4.03% THD were depicted in the DBFC at a switching frequency of 40 kHz. The results of the study were validated using detailed simulations and preliminary experiments.

Predicting the Influence of Aggregate Size and Distribution on Cementitious Concrete Properties: A Review

2025-06-11T15:52:53+00:00

Cement concrete has been in use for centuries as one of the primary construction materials. Its demand in the construction industry is expected to continue for several centuries before the full development of alternative products. However, one of the main areas of research interest is understanding how its constituents can be tailored to make its properties predictable to reduce risks associated with structural failures, reconstruction and reduced durability. These hindrances associated with cementitious concrete result from several attributes, including constituent material characteristics, mixing ratios and workmanship. Understanding the predictability of cement concrete properties requires computer modelling tools to provide reliable information for the mix design, construction, management and operation of cement concrete, and cement concrete structures. This paper reviews progresses in machine learning models for predicting cement concrete properties. Several algorithms have been reviewed, highlighting their applications, knowledge gaps and suggestions for future research. The paper provides a basis for selecting appropriate algorithms for predicting different concrete properties.

Development and Experimental Validation of a NonInvasive Blood Group Detection System

2025-06-11T20:48:09+00:00

An individual's blood group consists of red blood cell antigens whose composition is determined by protein presence, antigen structure, and gene series. Persons aged above six months have significant anti-A and/or anti-B in their serum. During transplantation and transfusion, ABO blood group identification is the most essential factor. The conventional method involves drawing blood samples from patients, and the blood group is determined based on the antigen-antibody reaction. This method consists of adding chemical reagents. However, this requires time of operation, and throughput analysis is high, and the process is also challenging to interpret. Accurate and rapid identification of blood groups is therefore crucial in various medical fields, including blood transfusions, organ transplants, and prenatal care. Traditional methods for blood typing often require extensive laboratory equipment and trained personnel, leading to delays and potential errors in critical situations. This research focuses on developing a non-invasive, compact, and user-friendly device capable of determining blood groups quickly without invasively collecting patient’s blood samples and using reagents. The system learns from a database of annotated blood samples by employing machine learning algorithms, enhancing its accuracy and reliability over time. A noninvasive blood group detection system was verified experimentally on a laboratory prototype, achieving an accuracy of 95.9% in identifying blood groups and rhesus factors. Furthermore, a comparative analysis was conducted between the proposed system and existing counterparts. This analysis demonstrated that the proposed system outperforms others in accuracy, indicating the rhesus factor

Comparative Analysis of the Efficiency of Reverse Osmosis and Hydroxyapatite for Fluoride Removal in Water: A Case of AUWSA

2025-06-11T21:18:28+00:00

Water treatment technology selection depends on contaminant type and budget. Fluoride removal from water is particularly challenging, requiring non-conventional treatment technologies (Radwan, 2023). Several regions in Tanzania, including Arusha City, are affected by fluoride contamination. With a population of 617,631 (Census, 2022), only 117,763 people currently have access to clean water supplied by AUWSA. This study aimed to compare the efficiency of Reverse Osmosis (RO) and Hydroxyapatite (HAP) in fluoride removal as a strategy to address water quality and supply challenges. Experiments were conducted using 6 m³ of raw water with fluoride concentrations ranging from 5.1 mg/L to 6.83 mg/L, sourced from boreholes. The HAP pilot plant was tested at 30-minute intervals from 8:00 AM daily for 21 days, while the RO system was tested with the same water volume at 5-minute intervals over the same period. Laboratory analyses of raw and treated water revealed that HAP had a lower fluoride removal efficiency of 91.51% to 93.41%, compared to RO, which achieved 96.05% to 97.66% removal efficiency. It was also revealed that RO loses about 30% of water during treatment, while HAp doesn’t lose any. Moreover, HAp uses locally available biogenic materials for treatment, enhancing sustainability. The findings suggest that the HAP treatment system is a practical and sustainable solution, offering effective fluoride removal while remaining affordable and energy-efficient, making it a viable choice for communities in need of clean and safe drinking water. This research addressed the problem of excess fluoride concentration in water and availability and access of clean water. Further research is recommended to evaluate the environmental implications of waste disposal following HAP media regeneration and the management of reject water from the RO filtration process. This assessment should focus on potential ecological risks, long-term sustainability, and the development of environmentally friendly disposal or reuse strategies.

A Review of Lithium-ion Battery Capacity Fade Deceleration at Power Fluctuations in Renewable Energy Systems

2025-06-11T21:52:50+00:00

Application of lithium-ion (Li-ion) batteries to store energy in renewable energy systems (RESs) is increasing due to their promising properties. Therefore, it is crucial to understand aging behaviours of Li-ion battery during RES life time as this directly affects cost of energy. Li-ion battery aging can be categorised into calendar aging and cycle aging. Calendar aging depends mainly on temperature and state of charge (SoC). In addition to temperature and SoC, cycle aging depends also on charge and discharge current rates and cut-off voltages. Higher current rates lead to faster Li-ion battery aging. It is necessary to identify appropriate battery power control strategies and their configuration to decelerate batteries’ aging in RESs. In this paper, a review of effects of power fluctuations on cycle life of Li-ion batteries in RESs has been done. Furthermore, hybrid energy storage systems (HESS), comprising battery system (BS) and supercapacitor (SC), topologies and control strategies are studied. Literature focussing on BS-SC systems in RESs was reviewed aiming at finding commonly used topologies and strategies. It has been found that the most commonly used methods in BS-SC HESS are classical strategies (70%) and fullactive converter topology (80%). The study recommends using classical control strategies and full-active converter topology during BS-SC implementation in RESs. Furthermore, the study recommends that future research should focus on evaluating in detail technical and economic factors of the identified control strategies and HESS converter configurations

Optimizing the Processing Temperature for Synthesis of Silver Nanoparticles within Cellulose-Wool Keratin supramolecular Matrix using Butylmethylimmidazolium Chloride Ionic Liquid

2025-06-11T22:05:18+00:00

To date, the synthesis of silver nanoparticles on the surface of cellulose and wool keratin biopolymer, while dissolved in ionic liquid, is attractive because of its biomedical potential. However, the optimal processing temperature for the nanoparticle formation is unclear. The previously reported temperature of approximately 120°C gives unpredictable results. The current study employs a combination of 50% cellulose and 50% keratin, along with 69 mg of silver chloride, in Butylmethylimidazolium Chloride BMImCl ionic liquid, using a singlepot process to produce a supramolecular film via non-derivatized mechanochemical interactions. The primary objective is to experimentally establish the processing temperature to achieve stable growth of metallic silver nanoparticles. The synthesis was conducted by heating the ionic mixture at temperatures of 110°C, 120°C, and 130°C. The study observed that raising the temperature to around 130ºC for 5 min is more practical. Moreover, though this data is higher, it does not compromise the thermal stability of cellulose and keratin's structure. The structural properties of the nanoparticles have been confirmed using Fourier transform spectroscopy (FTIR) and scanning electron microscopy (SEM). Furthermore, energy-dispersive X-ray spectroscopy (EDS) and powder X-ray diffraction (XRD) provide valuable insights into the physical characteristics of the produced silver nanoparticles, with a diameter of around 8.5 nm, and are uniformly distributed in-plane within the matrix. While the underlying mechanisms remain uncertain, they likely involve anchoring ionic silver onto the wool keratin while dissolved within the ionic liquid at elevated temperatures before reducing to metallic silver at room temperatures. Besides being sustainable, this green approach enhances understanding of the possibility of creating stable silver nanoparticles within the supramolecular matrix, which is essential for future applications in the biomedical field.

Assessment of Maintenance Performance Level of Selected Hydropower Plants in Tanzania

2025-06-11T22:10:49+00:00

Despite significant progress in increasing electricity access to over 78%, electricity reliability in Tanzania remains a concern, with frequent power outages reported. Maintenance issues in hydropower plants have been identified as a critical factor contributing to this problem. However, the specific maintenance performance levels have not been fully assessed. This study conducts a comprehensive evaluation of the maintenance performance of four key hydropower plants: Kidatu (204 MW), Kihansi (180 MW), Mtera (80 MW), and New Pangani Falls (68 MW). Data collected from staff surveys and maintenance records between 2018 and 2022 were used in the study. Although staff demonstrated a reasonable awareness of the hydropower plants Key Performance Indicators (KPIs), with a minimum mean score of 3.66, the findings reveal underperformance across all plants, with a heavy reliance on reactive rather than proactive maintenance. Low plant availability (89%), insufficient planned work (42%), and excessive unplanned work (55%) were recorded. High Mean time to Repair and frequent failures, particularly at New Pangani Falls, were also observed. This research underscores the importance of strategic maintenance improvements to enhance the reliability and efficiency of Tanzania's hydropower sector.

Evaluation of Thermal and Emission Performances of Briquettes Produced from Carbonized Corn Cob and Corn Husk

2025-06-11T22:28:02+00:00

The Mozambican agro-industrial sector relies heavily on various crops, with maize being the most significant. During processing, substantial waste is generated, which is often discarded as organic matter or burned, contributing to environmental pollution and the loss of potential energy resources. This study evaluated the thermal and emission performance of briquettes made from carbonized corn cob (CCC) and carbonized corn husk (CCH), using cashew nut skin as a binder for clean cooking applications. The briquettes were assessed against firewood and charcoal as control fuels, focusing on several energy performance parameters: water boiling time (WBT), combustion index (CI), thermal efficiency (TE), and emissions (E). Testing was conducted using an improved combustion stove (burnjikokoa). Results indicated a CI of 1.06±0.04 for carbonized corn cob briquettes (BCCCNS) and 1.14±0.03 for carbonized corn husk briquettes (BCHCNS). The WBTs (in minutes) were 17 for BCCCNS, 29 for BCHCNS, and 45 for both firewood and charcoal. Thermal efficiency was notably higher for BCCCNS (45%) and BCHCNS (42%) compared to charcoal (24.13%) and firewood (21.55%), suggesting that the selected waste materials are excellent for producing highenergy briquettes. In terms of emissions, particulate matter (PM2.5) levels were measured at 80 µg/m³ for both BCCCNS and BCHCNS, while firewood produced 190 µg/m³ and charcoal 120 µg/m³. Carbon monoxide (CO) levels were all below 200 ppm. These findings demonstrate the potential of utilizing agro-industrial waste to create sustainable and efficient cooking fuels.

The Royal Academy of Engineering, UK and The Enriching of Engineering Education Training and Practice Programme in Sub-Saharan Africa

2025-06-12T05:50:15+00:00

This paper elucidates initiatives taken by the Royal Academy of Engineering, UK, to overcome barriers in education and training in Sub-Sahara African higher learning engineering institutions. The said barriers include mismatches of curriculum, ineffectual teaching and learning and little exposure of academic staff to engineering practice. In order to overcome such barriers, the Royal Academy of Engineering established the two programmes in the region. The first one, Enriching Engineering Education Programme (EEEP) from 2014/15 to 2015/16 where the University of Dar es Salaam coordinated this programme as a hub for East African universities namely; Makerere University (Uganda), Moi University (Kenya), Dedaan Kimathi (Kenya) and Kenyatta Technical University (Kenya). A second programme which was implemented from 2015/16 to 2023/24, the University of Dar es Salaam also acted as a Hub for the local higher learning institutions namely; the Dar es Salaam Institute of Technology, Nelson Mandela, Mbeya University of Science and Technology, Sokoine University of Agriculture and National Institute of Transport under the new Higher Education Partnerships programme in Sub-Saharan Africa (HEPSSA); leaving Moi University and Makerere also to coordinate their own local universities under HEPSSA programme. All the above programmes involved capacity building in enhancing the outcomebased curriculum, problem-based learning, academia and industry staff exchange, student placements in industries, and technology business incubators/hubs practices. Conversely, the paper emphasizes the need establishing concordats of universities that will enhance collaboration of universities with industries in establishing joint research and development programmes for practical applications to technical and business problems facing the industry/private sector and the nation as a whole

The Impacts of Renewable Energy Sources: A Review on Grid Inertia and Frequency Regulation

2025-06-12T05:55:05+00:00

The power system is gradually transitioning into low inertia due to integrating substantial intermittency quantity of converter-based renewable energy sources, such as wind and photovoltaic power, into the current power grid network. This integration presents significant inertia and frequency control challenges to the network as a result of a decrease in the percentage of synchronous generators. Moreover, faster frequency deviations are posed by the mismatch between the supply and demand during contingencies, which creates difficulties in preserving the frequency stability of the power system. This research explores the impacts of renewable energy sources (RESs) on grid inertia and frequency management as key parts of preserving the power system's stability. Furthermore, the research article proposes mitigation ways to optimize both conventional synchronous generators and synthetic inertia for consistent and dependable functioning of the grid network while accommodating a growing share of renewable energy. The mitigation measures examined in this review research paper are synthetic inertia, fast frequency response, and battery storage systems

Towards Metrology 4.0 in Developing Countries’ Manufacturing Industries

2025-06-12T06:05:00+00:00

A systematic literature review was conducted to unveil the status of the digital transformation of metrology in developing countries, as they are lagging in utilising fourth industrial revolution (IR4.0) technologies to transform manufacturing industries. A PRISMA technique was employed using various keywords to identify, screen, and select the relevant literature. Forty publications were selected for the review, mainly discussing IR 4.0 technologies in metrological operations. The results indicate that the digital transformation of metrology has yet to be initiated in developing countries. However, the employment of IR4.0 technologies in advancing metrological operations in manufacturing industries is mostly discussed in the literature, especially in China and India. It was also evident that African countries lag behind their Asian counterparts in utilising the IR4.0 technologies to advance metrological operations in manufacturing industries. To enable sustainable digital transformation in metrology, national measurement institutes, testing and calibration laboratories, and manufacturing industries should embrace utilising IR 4.0 technologies in metrological operations. This will facilitate coordination and harmonisation of metrological operations within the three entities, eventually leading to sustainable digital transformation in metrology. The transformation in developing countries will enable precision, high-quality, and accurate metrological operations in manufacturing industries, leading to increased product quality and industry competitiveness in the international market. Also, industries could save time and cost while reducing errors in performing metrological operations. Moreover, the description of the phases that the manufacturing industries could go through towards Metrology 4.0 is also provided.

Mitigation of Voltage Disturbances in Industrial Power Distribution Networks Using Dynamic Voltage Restorers

2025-06-12T06:26:53+00:00

Most electrical and electronic equipment in industries require highquality power to function efficiently. Nonetheless, voltage sags and swells are pressing concerns and prone to directly impact the economy of industrial customers. One such customer embattled with these problems is Mbeya Cement Company Limited (MCC) located in Mbeya, Tanzania. These issues mainly are caused by upstream faults and switching operations. One way to address these is by utilizing the voltage injection method, which employs a power device known as a dynamic voltage restorer (DVR). In this paper, the voltage sags and swells of balanced three-phase, unbalanced double-line and single-line to ground faults are studied. Thereafter, mitigation strategies using the DVR are proposed for the MCC. A section of the MCC power distribution network fed from Tanzania Electric Supply Company Limited (TANESCO) Mwakibete substation with a 33 kV feeder is modeled using MATLAB/Simulink environment to mitigate the disturbances (sags/swells). The percentage of voltage sags and swells logged from the industrial feeder are 11 and 115%, respectively. To effectively utilize the DVR device, a control strategy is designed in the d-q-o reference frame, whereby the scaled errors between the source side of the DVR and its references for sags/swells corrections are considered. Simulation results revealed that the DVR performance handles both balanced and unbalanced voltage sags and swells by injecting the appropriate voltage to the supply, therefore, maintaining the load voltage at its nominal value. It can be concluded that the DVRs are recommended to be incorporated into the MCC feeders to mitigate the upstream disturbances. However, DVR performance comes at the cost of energy storage and DVR transformer rating. Further studies are encouraged to focus on the DVR performance optimization and cost implications

Towards Future Sustainable Infrastructure: The Role of Technical Audit in Tanzania’s Public Works

2025-06-12T06:53:12+00:00

This study aimed to investigate the vital role and impact of technical audits in promoting sustainable infrastructure development in Tanzania. The role and effects of technical audits in long-term infrastructure development were studied using a mixed-methods approach with both quantitative and qualitative parts. Data were collected through analysis of technical audit documentation, a semi- structured questionnaire, and stakeholder interviews. The study revealed the various dimensions of infrastructure investment projects, including initiation and planning, design, procurement of contractors and consultants, contract management, environment, health, and safety. The technical audit findings reported weaknesses or non- performance issues in infrastructure planning at the national level and in infrastructure projects, programs, and portfolios at various stages of their lifecycle that need to be addressed. The implementation of governance approaches aims to address environmental, social, and economic impacts and achieve investment objectives. The audited entities received recommendations for improvements to address non- performance issues. Furthermore, the timely implementation of these recommendations significantly contributed to the achievement of infrastructure development objectives. Based on the findings, the research concluded that technical audits play a significant role in promoting sustainable infrastructure development in Tanzania. The study recommended strengthening the institutional capacity of organisations overseeing technical audits by investing in training programs, professional development initiatives, and knowledge- sharing platforms. These initiatives will help to improve the technical expertise and competency of auditors and project stakeholders, who will consequently benefit from the technical audit of infrastructure development.

Comprehensive Review of Sensible Thermal Storage Systems for Cooking Applications

2025-06-12T07:14:51+00:00

Root Cause Analysis of Performance Degradation for an XYZ Thermal Power Plant in Tanzania

2025-06-29T09:58:58+00:00

Thermal power plants in Tanzania have been experiencing performance degradation, typically arising from component and subsystem failures, which contribute to power system instability and unreliability. This paper presents a case study of the root causes of performance degradation of an XYZ thermal power plant. The study was conducted by reviewing plant documentations, including maintenance and operational data logbooks, and by standardising the approach through the adoption of ISO 14224:2016 for maintenance and reliability data exchange. Data evaluation was carried out using principal component analysis and scree plot analytical techniques to enhance the depth and accuracy of root cause identification. Additionally, Pareto analysis was employed to determine the extent of the degradation. The findings revealed that plant performance degradation was primarily caused by local environmental factors (i.e. dust and air salinity) and operational practices at the plant level, including skills gap and non-adherence to recommended maintenance schedules. With regard to component and subsystem failure incidents, the majority were valve and ignition system failures, accounting for 11.5% and 10.9%, respectively. The main failure modes were external utility fluid leakage (ELU) and overheating (OHE), which accounted for 23.32% and 18.78%, respectively. Moreover, instead of the 34,848 hours planned for proactive maintenance activities based on Original Equipment Manufacturer (OEM) recommendations, the plant consumed 127,392 hours, with over 80% dedicated to reactive maintenance. In conclusion, timely and proactive maintenance, supported by knowledgeable and skilled personnel, is crucial in ensuring stability, reliability, and longevity of the XYZ thermal power plant.

Thermal Energy Storage System Using Silica Sand as Heat Storage Medium: Simulation of Geita Gold Mine

2025-06-29T10:06:43+00:00

Fuzzy Logic-Based Decision Support System for Adoption of Industry 4.0 Predictive Maintenance by Manufacturing Industries

2025-06-29T10:13:20+00:00

In the context of Industry 4.0, predictive maintenance enhances operational efficiency by optimizing processes, minimizing downtime, and improving cost-effectiveness. However, implementing predictive maintenance requires a systematic approach due to its complexity. This study collected expert input from 15 food and beverage manufacturing industries located in Dar es Salaam, Tanzania, using a purposive sampling technique. Six representatives were selected from each industry, and their opinions were analyzed using MATLAB 7.6 through a fuzzy logic inference system. The analysis focused on key factors influencing Industry 4.0 technology adoption for predictive maintenance, including adoption intention (strategic decision, equipment data, perceived benefit) and perceived usefulness (organizational culture, risk perception, external pressure). The results indicate that when strategic decision-making (technical function) is at 20%, equipment data quality at 15%, and perceived benefit (flexibility) at 25%, the adoption intention of the technology drops to 10%. The fuzzy logic system used techniques such as fuzzification, inference, and aggregation to assess the feasibility of predictive maintenance adoption. The model was validated and refined to ensure accuracy and relevance, offering decision support for maintenance planning and resource allocation. This Fuzzy Logic- Based Decision Support System provides a structured approach to overcoming the complexities of adopting predictive maintenance in Industry 4.0, helping manufacturing industries improve their operational efficiency and competitiveness.

Effects of Cutting Conditions on Tool Temperature and Material Removal Rate in Turning Operations

2025-06-29T10:17:58+00:00

Cutting conditions in manufacturing processes have effects on tool temperature and material removal rate. The objective of this study was to investigate the effects of cutting conditions namely spindle speed, feed rate, depth of cut and tool nose radius on tool temperature and material removal rate in turning operations. A total of 81 experiments were conducted to measure tool temperature and material removal rate in order to determine the effects of cutting conditions on tool temperature and material removal rate using ANOVA and regression analysis. The results show that tool nose radius, depth of cut, and spindle speed are significant to tool temperature, whereas feed rate is insignificant to tool temperature. Tool nose radius has the highest contribution to tool temperature with 44.43%, followed by spindle speed with 6.96%, depth of cut with 6.52%, and then feed rate with 0.08%, all with an error of 42.01%. In addition, spindle speed, feed rate, and depth of cut are significant to material removal rate while the tool nose radius is insignificant to material removal rate. The most important factor is feed rate, which contributes to 39.8%, followed by the depth of cut with 21%, spindle speed with 4.86%, and tool nose radius with 0.71% and an overall 33.64% contribution to the error. The findings conclude that tool nose radius may be closely controlled for generation of lower tool temperature while feed rate and depth of cut need to be thoroughly monitored to take advantage of higher productivity.

Optimal Placement of Distributed Generation Units in Power Distribution Networks Using Particle Swarm Optimization

2025-06-29T10:33:38+00:00

Power losses and voltage drops in distribution networks are critical issues in power system operation, reducing efficiency, reliability, and overall quality of the power supply to customers. Additionally, the rising electricity demand, deregulation of energy markets, and congestion in transmission networks have further contributed to the declining performance of the grid. To address these challenges, integrating distributed generation units (DGUs) into electric distribution systems has gained significant attention. Furthermore, the integration of DGUs into conventional fossil fuel-based power plants is becoming necessary to reduce greenhouse gas emissions. However, proper placement and sizing of DGUs are crucial for achieving optimal benefits. Inappropriate placement and sizing can lead to increased losses and degraded system performance, whereas optimal placement can enhance voltage stability and minimize power losses, thereby improving overall system performance. This study presents a particle swarm optimization (PSO) technique for determining the optimal placement and sizing of DGUs in power distribution networks. The proposed PSO approach considers voltage and power constraints to ensure operational requirements are met. The methodology is validated using IEEE 33-bus system simulations under three different scenarios: a network without DGUs, a network with one DGU, and a network with two DGUs. Simulation results demonstrate that optimal DGU placement significantly reduces power losses, minimizes voltage drops, and enhances system performance compared to a network without DGUs.

Potential use of Pump as Turbine Coupled to Self-Excited Induction Generator for Micro-hydro Cooking and Cooling Applications

2025-06-29T10:41:07+00:00

Clean cooking and efficient cooling in developing countries have recently become areas of great focus. Further, the environmental impact of flooding in high-capacity hydroelectric plants has become a major concern. As a result, there is growing emphasis on developing sustainable and decentralized energy solutions, focusing on the potential of micro-hydro systems, especially in rural and remote areas. Although there are several alternative energy generation methods, their application is not straightforward. One of the latest technologies under research is using pumps as turbines coupled to an induction generator. This paper explores through a rigorous experimental approach the possibility of using a pump as turbine (PAT) coupled with a self-excited induction generator (SEIG) as an alternative energy source for heating, lighting, and cooling applications. The 1.5 kW delta-connected induction generator was excited by three 50 µF star-connected capacitors. The cooking and cooling apparatus was represented by a resistive element with a fixed resistance and inductance seen by the generator. The results show that the PAT-SEIG system produced the required 240 V, which is sufficient to power ten 50 W LED bulbs or power a compressor for a cooling system. The study has demonstrated that PAT-SEIG can offer an alternative, cost-effective solution for generating electricity to power cooking or cooling appliances.

Mechanical Properties of Pineapple Braided Fabric Reinforced Epoxy Matrix Composite Fabricated via Vacuum-Assisted Resin Infusion Moulding

2025-06-30T21:12:18+00:00

Fibres and fabrics obtained from lignocellulosic materials have attracted attention as reinforcements in polymer composites due to their competitive mechanical and ecological benefits. While the potential of randomly oriented pineapple leaves fibres (PALF) in composites have explored in previous studies, the mechanical behaviour of braided PALF fabric composites fabricated via vacuum- assisted resin infusion moulding (VARIM) remains relatively unexplored. In this study the tensile, compression and flexural strengths of epoxy-based composite containing 40 vol.% braided pineapple fabrics, fabricated using VARIM, for load carrying applications were investigated. The results revealed that the three- layered unbleached pineapple braided fabric composites exhibited a tensile strength of 845.1 MPa, the ones from bleached fabrics exhibited a higher tensile strength of up to 996.7 MPa, attributed to enhanced fibre-matrix adhesion resulting from the bleaching process. Additionally, the bleached fabric composites displayed a superior flexural strength of 55.6 MPa for the three-layered configurations, highlighting further the potential of both the bleaching and braiding processes for higher load carrying capacity applications. The results underline the potential of the layered braided pineapple fabric composites, especially the bleached variants, for engineering applications that demand a balance of strength, stiffness, and flexibility. This study not only advances the understanding of the braided PALF fabric composites but also highlights their viability as sustainable alternatives to synthetic fibre reinforcements. By exploiting the properties of pineapple fibre bundles and the VARIM fabrication technique, this research contributes to the endeavours to develop high-performance and eco-friendly composite materials for a diverse engineering application.

Calibration of Measurement Tools in the Experimental Test Rig for Hydropower Performance Evaluation

2025-06-30T21:26:07+00:00

The demonstration of a typical hydropower plant requires the development of a test rig with the installation of tools to measure the performance parameters. The measurement tools require a calibration process to improve the quality of recorded data. This study involved the calibration of traditional and automated measurement tools connected to the hydropower test rig through an Arduino microprocessor. The automated measurement tools included a pressure transducer, flow meter, digital tachometer, and torque transducer, while traditional measurement tools, including a pressure gauge, concrete water tank, contact tachometer, and force lever arm balance, were connected in the same test rig during the calibration process. Arduino microprocessor was employed with code to generate signals when connected to automated measurement tools. The results of automated tools varied linearly with traditional measurement tools, with R-squared closer to 1. Therefore, this study recommended that calibrating automated measurement tools during experimental testing is essential for accurately assessing the performance of the test rig development.

Arduino microprocessor; head; hydropower test rig; rotational speed; flow rate.

Fuzzy-AHP Based Decision Support System for the Selection of Optimal Maintenance Strategy for Meter Gauge Railway Infrastructure: A Review

2025-06-30T21:49:16+00:00

There are many uncertainties and complexities associated with maintaining Meter Gauge Railway (MGR) infrastructure, which calls for a methodical approach to decision-making. The development and application of a fuzzy-AHP-based decision support system (DSS) to select the optimal maintenance strategy for the MGR are presented in this study. The review covers research from 2013 to 2023 and focusses on the use of Multi-Criteria Decision Making (MCDM) and Fuzzy Analytic Hierarchy Process (Fuzzy-AHP) techniques in railway infrastructure maintenance. To manage the inherent uncertainties and subjective judgements involved in maintenance decision-making, the Fuzzy-AHP methodology combines fuzzy logic with the Analytic Hierarchy Process (AHP). By assessing and prioritising maintenance strategies, this Fuzzy-Based DSS seeks to improve the MGR infrastructure's reliability, dependability, safety, and efficiency. The analysis reveals that while Fuzzy-AHP has been widely adopted for decision support in infrastructure maintenance, there remains a significant research gap in applying these systems to Meter Gauge Railways, particularly in developing regions. The review underscores the need for more targeted studies and suggests potential avenues for future research, including the exploration of hybrid DSS models and the application of advanced computational techniques. The findings offer insightful information to officials and railway operators about the efficacy of the Fuzzy-AHP-Based DSS in enhancing maintenance performance and optimising resource allocation.

Performance Dynamics of Activated Carbon-Methanol Pair in Adsorption Refrigeration Systems

2025-06-30T21:57:27+00:00

The Role of Internal Factors on Vehicular Mobility

2025-06-30T22:06:07+00:00

Vehicle mobility internal factors are influenced by the performance state of the road surface quality, governor, engine, gear train, differential unit and mobility unit. Studies on vehicular mobility models exist for off-road external factors but absent on on-road internal factors. The on-road internal factors model describes the vehicular mobility performance as a function of internal factors. In the current undertaking, results are generated by the determination of mobility performance characteristics with the application of 2nd Order Ordinary Differential Equations and using Laplace operator with MATLAB Software simulation. The effect of road surface against the time taken varies accordingly. At a pedal force of 50 N, a higher road roughness, indicated by an International Roughness Index (IRI) of 2.8 m/km, was observed on a road segment with notable roughness. The time ensued is 96.0 seconds at a tractive force of 4500 N on pedal force of 50 N indicating a longer transacted time and low fuel displacement resulting in lower engine revolution speed. The lowest roughness at a value 2.0 m/km, time taken was 17.5 seconds to cover the distance at a tractive force of 17750 N. The results suggest that the greater road roughness (IRI) may lead to a longer time taken to cover the distance. As a consequence of high IRI a vehicle travels more slowly and impact on overall mobility. Thus, maintenance on the road surface should be done regularly to better road surface quality.

Review on Gas-to-Liquids Conversion Technology: Lessons from Case Studies and Potential Strategies for Implementation in Tanzania

2025-06-30T22:17:49+00:00

This review paper explores the transformative potential of Gas-to- Liquids (GTL) technology for harnessing Tanzania's vast natural gas resources. With significant discoveries of natural gas reserves totalling up to 57 Tcf in fields such as Songosongo, Mnazi Bay, Block 1, 2, 3 and 4. Tanzania is positioned to leverage GTL technology to convert these resources into high-value liquid fuels like gasoline, diesel and naphtha. Review of GTL process, its products and applications has been done. By analysing successful GTL projects globally and drawing lessons applicable to Tanzania, this paper provides strategic recommendations for policymakers and stakeholders to foster GTL development. It further addresses the potential considerations that Tanzania may be required to attain with GTL implementation, including capital projections, technological complexities, and the need for supportive policy frameworks. GTL technology does not only promise to enhance energy security and reduce dependency on imported fuels but also offers substantial economic benefits through job creation, infrastructure development and increase export revenues. Adoption of GTL technology in Tanzania could play a pivotal role in diversifying the energy mix, enhancing economic growth and promoting sustainable development.

Towards Effective Academia-Industry Collaborations: The Case of Higher Learning Institutions in Tanzania

2025-06-30T22:24:50+00:00

Industries are the main consumers of products from higher learning institutions (HLIs); graduates for employment and research outputs for socio-economic development. Research outputs from HLIs are commercialized as services or products facilitated by academia- industry collaborations. The collaborations are expected to address mismatch between labour market needs and HLIs’ products, which has resulted in graduates’ employability challenges. Despite their importance, effective academia-industry collaborations remain challenging. This study explores the effectiveness of Academia- Industry collaborations established by HLIs in implementing the Higher Education Economic Transformation (HEET) project (2021- 2026) in Tanzania. One of the project objectives is to build functional linkages between industry and HLIs to align graduates with needs of labour market. The study explored the quantity and types of collaborations established, enablers and barriers, strategies to align graduates with market needs, and sustainability. Using a mixed- method approach, data was collected from eighteen out of nineteen participating institutions through an open-ended questionnaire. By June 2024, HLIs had established 2 to 23 collaborations, with joint research being the most common type of collaboration. Key enablers were institutional support and mutual benefit. Funding constraints and bureaucratic delays were the common barriers. Strategies for aligning HLIs outputs with market needs included enhancing practical skills for both staff and students, curriculum reviews, and institutionalizing the collaboration. Engagement, formal agreements and regular reviews were the strategies for collaboration sustainability. The study results serve as useful feedback to the HLIs, industries, and inputs to policymakers in facilitating effective academia-industry collaborations.

Energy Optimal Coverage Motion Trajectory Generation using a Fourth-order Motion Profile

2025-06-30T22:32:08+00:00

Industrial machines are widely used in manufacturing sector to manufacture several products to meet customer demands. Most of these industries runs all the time throughout a day leading to high operating cost. To cut costs and satisfy customer demand for precise products, industrial machines’ motion generation is important in improving machine motion precision while using less energy. This study presents a coverage motion energy optimization which is generated by linear interpolation of each segment described by the fourth-order motion profile. The phase changes in the profile are attained with continuity of machine kinematic limits jerk, acceleration, and velocity, which are crucial to realize accurate motion. Genetic Algorithm is used to generate an optimal coverage motion using the convergence approach whereby the converged solution is selected as the final solution achieving minimum energy consumption. The simulation study is provided to illustrate the effectiveness of the proposed technique. The energy saving is about 9.27% when compared to unoptimized path. The approach can be utilized in several industrial machines employing coverage motion with the processes such as polishing, milling, laser cutting, and inspection.

Wet gas metering performance using conventional flow measurement devices

2025-06-30T22:38:39+00:00

The demand for and production of natural wet gas from wells has significantly risen in recent years. Although natural gas liquids hold substantial value in the oil and gas market, their presence in wet gas adversely affects gas metering, leading to overreading during measurement. A comprehensive study has been undertaken to formulate and enhance correlations for rectifying overreading in wet gas metering. Nevertheless, most current correlations are designed for horizontal configurations of traditional meters. Mitigating this constraint is crucial to consider the impact of gravity on pressure loss in vertically oriented systems. This study seeks to evaluate the efficacy of wet gas overreading correlations utilizing a vertically positioned Venturi flow meter, a recognized instrument for single-phase flow measurement. This project innovatively examines the influence of liquid film formation and flow along the walls of the pressure measurement zone within the Venturi tube. This liquid coating influences differential pressure, and its influence on wet gas overreading correction will be examined using established correlations.

Assessment of Digital Solutions for Conformity Assessment of Legally Controlled Measuring Instruments in Tanzania

2025-06-30T22:47:40+00:00

The advent of state-of-the-art digital technologies since 2011 has led to the digital transformation of legal metrology practices to ensure the trustworthiness of software-controlled measuring instruments globally. Despite the digital transformation in legal metrological practices, the conformity assessment of legally controlled measuring instruments is manually done (i.e., paper-based) in Tanzania. The paper-based conformity assessment of legally controlled measuring instruments is prone to error and lacks efficiency and effectiveness. This study aimed to assess digital solutions for improving conformity assessment through a comprehensive survey conducted across various regions in Tanzania, targeting a stratified sample of 51 respondents from organizations involved in legal metrology. Data was collected using structured questionnaires. SPSS® 23.0 analyzed the collected data. The reliability testing through the Cronbach’s alpha value was 0.887, implying high internal consistency of the data collected. The findings revealed that the awareness level spans from neither aware to fully aware. The overall readiness level was as follows: digital solutions (level 2), instrument (level 3), infrastructure (level 3), skilled personnel (level 2), financial arrangement (level 2) and government policy (level 4). The overall readiness level approximated to level 4. Thus, the findings indicate that there is an intermediate level of readiness to adapt state-of-the-art technologies to enhance conformity assessment of legally controlled measuring instruments. Approximately 75% of respondents are aware of various digital solutions for conformity assessment of legally controlled measuring instruments, including digital conformity assessment certificates, digital twins for products and instruments, and smart sensors.