Digital Commons Network^™

Integrating Gis With Interim Payment Valuation In Road Construction Projects: A Conceptual Framework, Abdulrahman I. Iro, Juma M. Matindana, Julian Ijumulana

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Interim Payment Valuation is a critical process in road construction contract administration, yet conventional valuation practices remain heavily dependent on manual measurements, fragmented documentation, spreadsheets, and professional judgement. These limitations can affect measurement accuracy, transparency, traceability, and the timeliness of payment certification. Although Geographic Information Systems have increasingly been applied to construction planning, quantity measurement, progress monitoring, infrastructure management, and decision support, their integration with contractual and financial processes for interim payment valuation remains insufficiently explored. This study therefore develops a conceptual framework for integrating GIS with Interim Payment Valuation in road construction projects. A PRISMA-guided structured literature review …

A Tool For Assessing The Effectiveness Of Speed Humps As Traffic Calming Measure, Abdulrazak Mzamiru Kachwamba, Enock W. Nshama

Tanzania Journal of Engineering and Technology (TJET)

Urban population growth and increasing motor vehicle usage continue to raise concerns regarding road safety in rapidly developing cities. Although previous studies have assessed traffic-calming effectiveness using multiple criteria, they have analysed the criteria separately and have not developed a composite tool for classifying overall effectiveness. This study develops a quantitative assessment tool designed to compute a weighted composite score for evaluating the effectiveness of speed humps as a traffic calming measure. Stakeholder questionnaire responses, complemented by descriptive analysis and exploratory factor analysis, were used to identify key indicators of effectiveness and the variables influencing them. Findings indicate that speed …

Artificial Neural Network-Based Modelling And Prediction Of Key Performance Indicators In Road Construction Projects, Hussein Mativila, John M. Kafuku, Beatus A. T. Kundi

Tanzania Journal of Engineering and Technology (TJET)

Road construction projects in developing countries including Tanzania experience several challenges including cost overruns, schedule delays and poor quality. The causes of these challenges include complex interdependencies project’s uncertainty factors. This makes traditional methods for predicting Key Performance Indicators (KPIs) less effective. This study has developed a robust Artificial Neural Network (ANN) model for accurate modelling and predicting KPIs for road construction projects in Tanzania. The analysis was based on data obtained from 281 projects implemented by TANROADS in 11 regions from 2015 to 2025. Fourteen uncertainty factors were measured on a five-point Likert scale and screened using Principal Component …

Voltage-Related Power Quality Issues And Impacts On Distribution Networks With Sensitive Loads - A Review, Godwin Elinazi Mnkeni, Jackson Justo, Aviti Thadei Mushi, Bakari M. M. Mwinyiwiwa

Tanzania Journal of Engineering and Technology (TJET)

Voltage disturbances are the most important power quality (PQ) complications that customers and power utilities face in this smart era. The growing adoption of sophisticated electronic equipment and integration of renewable energy sources (RES) into power grids has increased the susceptibility of power distribution networks (PDNs) to voltage sags, swells, interruptions, flicker, and voltage imbalance. These disturbances, mainly caused by upstream faults, switching operations, and RES integration, compromise voltage PQ and system reliability. Consequently, they accelerate equipment degradation, increase electronic waste (e-waste), raise reactive power demand and maintenance costs, increase power losses, and impose substantial economic losses on customers and …

Disturbance-Learning Inertia Estimation Using Artificial Neural Networks For Power System Stability, Sospeter Igaanja Gabriel, Francis Mwasilu, Peter Makolo Dr.

Tanzania Journal of Engineering and Technology (TJET)

ABSTRACT

Power systems are progressively shifting towards low inertia as a result of incorporating significant amounts of intermittent and converter-based renewable energy sources, such as wind and solar power, into the current power grid network. This integration poses considerable problems to inertia and frequency control within the network due to a reduction in the proportion of synchronous generators. Furthermore, rapid frequency deviations occur due to the disparity between supply and demand during contingencies, complicating the maintenance of frequency stability within the power system. The disturbance-learning inertia estimation method for power system stability is presented. The simulation analysis is performed using …

Hybrid Transformer-Bilstm Model For Early Fault Detection And Multiclass Classification Of Wind Turbine Faults Using Scada Data, Hassan Y. Mkindu

Tanzania Journal of Engineering and Technology (TJET)

Early and accurate fault detection in wind turbines is essential for improving operational reliability, reducing maintenance costs, and minimizing unplanned downtime. This study proposes a Hybrid Transformer-BiLSTM deep learning model for early fault detection and multiclass fault classification using Supervisory Control and Data Acquisition (SCADA) data. The proposed architecture combines the Transformer's self-attention mechanism to capture global temporal dependencies with the Bidirectional Long Short-Term Memory (BiLSTM) network's ability to model sequential fault evolution, enabling effective learning of multivariate time-series data. The model was developed and evaluated using the recently introduced CARE SCADA dataset, classifying five operating states: No Fault, Transformer …

A Quad-Port Dual-Band Elliptical Patch Mimo Antenna For 5g And Wlan Applications, Livingstone L. Kimaro, Hashimu Uledi Iddi, Mussa M. Kissaka, Neema S. Joseph

Tanzania Journal of Engineering and Technology (TJET)

A dual-band multiple-input multiple-output (MIMO) antenna for wireless local area network (WLAN) and fifth-generation new radio (5G NR) band n104 applications is presented. Two U-shaped slots interconnected back to back are etched on an elliptical shaped patch, four identical patch elements are then arranged orthogonally to form a quad-port antenna that resonates at 5.8 GHz and 6.7 GHz. Without additional extrinsic decoupling structures, the proposed design achieves measured isolation levels above 25.13 dB and 21.31dB, realized gains of 7 dBi and 7.2 dBi and -10 dB impedance bandwidths of 155.4 MHz and 90 MHz in the lower and upper frequency …

Design Of Permanent Magnet Synchronous Motor For Railways Traction Application, Anna S. Mwang'onda, Jackson J. Justo, Francis Mwasilu

Tanzania Journal of Engineering and Technology (TJET)

This paper presents the design of surface mounted permanent magnet synchronous motor (SMPMSM) intended for traction applications in standard gauge railway (SGR) for passengers. The proposed motor is rated 350 kW with a base speed of 3000 rpm. Moreover, speed control strategy with stability analysis is incorporated in the design to validate the performance of the SPMSM. The simulation results achieved a torque of approximately 1115 Nm at a terminal voltage of 800 V. The flux linkage of 150 mVs which ensures effective electromagnetic pertinence while maintaining safe magnetic loading because the flux density is less than 1.5 T. The …

Recent Advances In Bioethanol Production From Water Hyacinth: A Critical Review, Umuamina A. Matola, Mahir Mohammed Said, Olga-Ioanna Kalantzi, Abraham K. Temu

Tanzania Journal of Engineering and Technology (TJET)

Water hyacinth (WH) is a highly invasive tropical aquatic weed with high holocellulose and low lignin content, making it a promising lignocellulosic feedstock for second-generation bioethanol production. Producing bioethanol from WH offers a sustainable approach to simultaneously managing invasive biomass and producing renewable energy. This review critically evaluates recent advancements in bioethanol production from WH by examining pretreatment, hydrolysis, and fermentation technologies reported between 2014 and 2024. A PRISMA-guided literature search was conducted using the Scopus and Web of Science databases, and fifty-nine original research articles were selected for analysis. The reviewed studies were comparatively assessed based on pretreatment strategies, …

Exploring Consultancy-Related Variations In Public Building Projects: A Review Towards A Management Framework, Grayson Bambaza, Ismail W. R. Taifa, George S, Mwaluko

Tanzania Journal of Engineering and Technology (TJET)

Consultancy-related variations remain one of the leading causes of cost overruns, schedule delays, quality deficiencies, and contractual disputes in public building projects. Although various studies have been undertaken to document the causes of variations in construction works, the same level of interest has not been shown for consulting services variations across the consulting services spectrum and their consequences for effective management. This study explores variations in consulting services for public works by systematically reviewing the existing literature using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta Analyses) guidelines. Relevant articles published from 2020 to 2026 were retrieved from …

Urban Spatial Development Control In Tanzania: Analysis Of Factors Influencing Gis Application Using Structural Equation Modelling (Sem)., Happiness Protas Mmanda, Nestory Yamungu

Tanzania Journal of Engineering and Technology (TJET)

Rapid urbanization in developing countries has intensified urban expansion, creating challenges for sustainable development. Geographic Information Systems (GIS) enhance spatial planning, but empirical evidence on factors influencing their effectiveness remains limited. This study examines determinants of GIS application in Urban Spatial Development Control (USDC). The objectives are to (1) identify and categorize factors affecting GIS use, (2) assess relative strength, and (3) develop a validated structural model explaining GIS adoption in USDC. Data were collected from 103 LGAs by a mixed sampling method. Exploratory and Confirmatory Factor Analysis classified influencing factors into technology-related (α = 0.869, CR = 0.881), process-related …

Decision Support Tool For The Maintenance Of Meter Gauge Railway Permanent-Way Infrastructures: A Concept Paper, Hamisi J. Maulid, Beatus A.T Kundi, Juma M. Matindana, Ismail W. R. Taifa Dr

Tanzania Journal of Engineering and Technology (TJET)

A Decision Support Tool (DST) represents a transformative way of modernising maintenance practice on the permanent-way infrastructure of Meter Gauge Railway (MGR). Maintenance practice remains largely reactive, as the MGR plays a strategic role in transporting both freight and passengers, resulting in inefficient resource allocation, high operational risk, and growing Lifecycle expenses. This concept paper explores the potential and the design challenges for a DST that combines fuzzy analytic hierarchy process (Fuzzy-AHP) modelling, multi-criteria decision analysis (MCDA), Geographic Information Systems (GIS) and predictive machine learning (ML) analytics for evidence-based, future-oriented maintenance management. The paper draws on peer-reviewed studies from …

Effect Of Sugarcane Bagasse Ash Incorporated With Limestone Calcined Clay Cement On Geotechnical Properties Of Swelling Soils Relevant To Road Applications, Horris K. Nangulama, Siya P. Rimoy, John E. Elvis

Tanzania Journal of Engineering and Technology (TJET)

This study aims to investigate the use and effect of sugarcane bagasse ash (BA) incorporated with limestone calcined clay cement (LC³) as a sustainable and cost-effective alternative for stabilizing swelling soils. Therefore, BA incorporating LC³ was added to black cotton soil (BCS), known for its high swelling potential. Series of laboratory tests including free swell index (FSI), compaction, California bearing ratio (CBR), and shear strength were conducted to evaluate the performance of BA incorporating LC³ binder-stabilized BCS. Additionally, microstructural analyses using pore size distribution (PSD), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were performed to …

Hydro-Chemical And Bacteriological Assessment Of Zanzibar Groundwater Resources, Subira Munishi, Andrew Kimati

Tanzania Journal of Engineering and Technology (TJET)

Groundwater is the primary freshwater source in Zanzibar, sustaining domest ic, agricultural, and tourism needs. Increasing demand has intensified the pressure on this limited resource and has led to over-abstraction and contamination. Amid the growing demand and contamination pressures, this study examines the quality of groundwater in Zanzibar to clarify current conditions and emerging risks, and inform resource management and public health priority interventions. Particularly, the present hydro-chemical and bacteriological quality and variability was examined for both Unguja and Pemba Islands. A total of seventy-two samples were collected using a stratified random sampling approach, with the first field campaign focusing …

Hybrid Solar - Coal Thermal Energy System For Industrial Process Heat At Sayona Drinks Limited In Tanzania, Santos Kihwele, Elisha D. Bitesigirwe

Tanzania Journal of Engineering and Technology (TJET)

Over the past two decades, global efforts to mitigate pollution from conventional energy sources have intensified, with coal remaining a major contributor to carbon emissions. While fossil fuels cannot be eliminated from thermal generation in manufacturing industries, particularly in middle‑income countries such as Tanzania, they continue to dominate as the primary energy source. Industries including food and beverage, paper, textile, paints, chemicals, and pharmaceuticals require substantial thermal energy for heating and drying, and typically rely on coal and natural gas.This study introduces a unique application of a parabolic trough solar thermal system with integrated thermal energy storage, specifically tailored to …

Compact Low-Profile Dual-Band Microstrip-Fed Monopole Antenna For Wlan And Lte Applications, Hashimu U. Iddi

Tanzania Journal of Engineering and Technology (TJET)

The rapid advancement in wireless communication technologies has led to rising user demand for high-speed data transfer, seamless connectivity, and improved wireless communication efficiency. Therefore, it is inevitable to develop efficient and compact antennas which can support different frequency bands of various wireless system standards in mobile devices. A compact, low-profile microstrip-fed monopole antenna operating in dual bands, 2.45 GHz and 5.8 GHz, and suitable for WLAN and LTE applications is proposed in this study. The proposed antenna’s radiating element was carefully designed using slotting techniques and optimising the various parameters for achieving the required resonance frequency. The proposed compact, …

Trajectory-Based Model Predictive Control For Rotary Crane Sway Suppression With Only Horizontal Boom Actuation, Haryson J. Nyobuya

Tanzania Journal of Engineering and Technology (TJET)

Safety is of biggest importance in construction and industrial activities involving rotary cranes. These cranes are huge and responsible of moving large parts or/and materials from different positions. Now operating these cranes tend to be subdue to pay load oscillations when moving the load for which is extremely dangerous when not suppressed. This study proposes the generation of trajectory using Model predictive control approach with reduced control horizon compared to state horizon. Reduced control horizon design reduces computational time for trajectory generation while maintaining the pay-load sways to a minimum. In this approach the complex dynamic model is reduced to …

On The Use Of Lorawan For Smart Fishing Applications In The Blue Economy Sector, Eva Shayo

Tanzania Journal of Engineering and Technology (TJET)

The growth of digital technology is expected to transform small-scale fishery sectors, where a need for robust, low-cost, long-range communication networks becomes critical. There exist several technologies that are used in the fishery sector but they are never affordable to small scale fisheries. This study evaluates the feasibility of using low cost Long Range Wide Area Network (LoRaWAN) technology specifically tailored for smart fishing environments to small scale fishery sector. Using simulation, we assess the performance of the key performance metrics including probability of success and energy efficiency under varying device densities and time. During evaluation, we considered end devices …

Optimal Design And Techno-Economic And Environmental Analysis Of A Hybrid Solar Pv-Battery-Generator System For Off-Grid Telecom Towers And Rural Households: Case Of Misughaa Village In Tanzania, Ibrahim Mwammenywa, Martha Mwaikenda

Tanzania Journal of Engineering and Technology (TJET)

Telecommunication services are pivotal for the socio-economic development of communities, regions, and countries. Extensive and reliable telecom infrastructure enables populations to leverage development opportunities and bridge the urban-rural divide. However, extending these services to rural areas often necessitates the deployment of telecommunication towers in locations lacking national grid access. Consequently, service providers typically rely on diesel generators (DG) for power, which introduces significant challenges. These challenges include a high operational expenditure (OPEX), rendering telecom services unaffordable for rural communities, and substantial environmental pollution from greenhouse gas (GHG) emissions. This study aims to present an optimal design, encompassing sizing and economic …

Physicochemical Properties And Chemical Compositions Of Cashew Nut Shell Liquid Extracted With Carbon Dioxide–Expanded Hexane, Neema Msuya, Joseph Yn Philip, Frank Jacob, Kando K. Janga

Tanzania Journal of Engineering and Technology (TJET)

Cashew nut shell liquid (CNSL) is a mixture of phenolic compounds that can effectively replace commercially available phenols in various applications. This study investigated the physicochemical properties and chemical composition of CNSL extracted using CO₂–expanded hexane (CXH) and compared to the traditional Soxhlet extraction method. Steamed cashew nut shells (sCNS) were used in both cases.  The CXH was carried under varying CO₂-mole fractions (0.468-0.892) and temperatures (20-36 °C) whereas Soxhlet extraction was performed at atmospheric pressure and hexane boiling point. Response Surface Methodology (RSM) with Central Composite Face-Centred Design (CCFD) was employed to evaluate the effect …

Voltage Profile Enhancement In Iliceto Shield Wire Scheme For Rural Electrification: Case Study Of Chalinze-Mbwewe Transmission Line In Tanzania, Ebeneza Chaula, Ibrahim Mwammenywa, Santos Kihwele

Tanzania Journal of Engineering and Technology (TJET)

Rural electrification faces challenges due to significant voltage drops over long transmission distances, affecting reliability and power quality. While the Iliceto Shield Wire Scheme (ISWS) offers a modern cost-effective solution, voltage stability remains a challenge. This study analyses voltage profile enhancement within ISWS, focusing on the Chalinze-Mbwewe section of the 132 kV transmission line, using LTSpice simulations. Due to LTSpice limitations, direct solar PV integration was mimicked by introducing a secondary voltage source at each load centre, producing 33 kV to match the original source voltage. This approach maintained improved voltage profile from Msoga Village to Mbwewe over 80.9 Kilometers. …

The Impact Of Gender Sensitization On Requirements Elicitation: A Controlled Experiment, Ruthbertha Kateule, Salome Maro, Leonard Peter Binamungu

Tanzania Journal of Engineering and Technology (TJET)

Previous studies in software engineering have reported the importance of considering gender aspects in various software engineering activities, including requirements engineering, however, to the best of our knowledge, no work has investigated the impact of gender sensitisation on eliciting gender inclusive software requirements. The objective of this study was to understand the impact of gender sensitisation on software requirements elicitation. We conducted a controlled experiment using 40 undergraduate students from three different computing programs at the University of Dar es Salaam. The 40 participants were divided into 9 groups with both males and females. The participants were asked to elicit …

Enhancing Community Engagement Through ‘Nitunze Kilombero’ Mobile App: Case Of Climate Land Use And Cover Management For Kilombero Basin, Ghanima Chanzi, Subira Munishi

Tanzania Journal of Engineering and Technology (TJET)

The Kilombero Basin in southeastern Tanzania faces significant challenges due to rapid land use and land cover (LULC) changes driven by climate change, population growth, and unsustainable farming practices. This study assessed the role of community engagement and digital reporting through the 'NITUNZE KILOMBERO', mobile application in supporting water resources management in the basin. The App facilitates real-time reporting of environmental issues, provides educational resources, and enables collaboration between local communities and authorities. A mixed-methods approach, including household surveys and key informant interviews, was employed to assess the app's effectiveness. Results indicate high community awareness of LULC impacts, with 85% …

Load Flow And Fault Performance Evaluation Of Interconnected Minigrids In Uganda Using Digsilent Powerfactory, Prossy Mutesi, Santos Kihwele, Emmanuel Matee

Tanzania Journal of Engineering and Technology (TJET)

The increasing demand for decentralized, reliable electricity in rural Sub-Saharan Africa has catalyzed the deployment of minigrids as an intermediate electrification strategy. This study investigates two solar photovoltaic (PV) mini-grids: Kyamugarura and Kanyegaramire, located in western Uganda, approximately 3km apart. Each mini grid initially consisted of 13 kW installed photovoltaic (PV) capacity, supplying power to households and small businesses. Due to rising demand and regular evening blackouts, both mini-grids are being upgraded to 57 kWp each. The integration of these upgraded systems into the national utility grid is proposed and simulated to evaluate performance improvements under two medium-voltage interconnection options: …

Leveraging Convolutional Neural Networks For Through-The-Wall Radar Imaging: Challenges, Impacts, And Future Directions, Tumaini Edgar, Abdulla F. Ally, Abdi T. Abdalla

Tanzania Journal of Engineering and Technology (TJET)

Through-the-wall radar imaging (TWRI) is an essential technology for military and rescue applications; however, its performance in detecting and visualizing high-quality images of targets behind walls is significantly degraded by multipath reflections and signal attenuation. This paper reviews the current state of TWRI and its challenges, and explores the transformative potential of deep learning, particularly convolutional neural networks (CNNs), in addressing these challenges. Peer-reviewed articles published from 2018 to 2024 were analysed to examine CNN applications in addressing TWRI challenges. The analysis reveals that using CNNs, TWRI systems can be more effective by filtering wall distortions, reducing noise, lowering computational …

A Review Of Energy Storage Technologies With Hydro Energy System Design For Off-Grid Electricity, Daniel H. Ngoma, Banet L. Masenga

Tanzania Journal of Engineering and Technology (TJET)

Many renewable energy sources such hydropower—particularly small-scale run-of-river and micro-hydro—offers reliable, low-cost generation. However, their inherent intermittency (due to seasonal flow variations) and inability to instantly match demand necessitate integrated energy storage to ensure a stable, continuous power supply. This review synthesizes contemporary energy storage technologies in the context of their integration with off-grid hydro energy system design.

The study examine a spectrum of storage solutions, evaluating their technical characteristics, costs, and suitability for hybrid hydro applications. Pumped Hydro Storage (PHS), while highly efficient and large-scale, is often geographically constrained and capital-intensive for small off-grid projects. Battery Energy Storage Systems …

Revitalising Tanzania’S Textile Industry Through The Uk Textile System’S Role, Charles M. Kahabi

Tanzania Journal of Engineering and Technology (TJET)

Currently, there is the environmental and social challenges emerging from the global clothing and textile industry, specifically on textile waste management.  Additionally, the flow of second-hand clothing (SHC) between European countries especially the UK and Tanzania is increasing. In the UK, rapid growth of second-hand clothing (mitumba) driven by fast fashion results in vast quantities of discarded garments, of which only a fraction is recycled, leaving the remainder in landfills. Conversely, Tanzania has long depended on imported SHC a practice that, while affordable, has undermined local textile industries and contributed to waste accumulation. By examining Tanzania’s textile landscape, the research …

Optimization Of Vehicle Mix For Three-And Four-Wheel Passenger Transportation System In Nigeria, Omotunde A. Muyiwa, Hamid A. Jimoh, Kolawole T. Oriolowo

Tanzania Journal of Engineering and Technology (TJET)

Efficient transportation systems are essential for reducing passengers waiting times in densely populated areas. However, there is a dearth of information on the optimization of vehicle mix for three-and four-wheel transportation systems in Nigeria. The present study was designed to optimize the vehicle mix for three-and four-wheel passenger transportation to improve transportation efficiency. Twenty purposively selected vehicles were observed, while a queuing model (M/M/s) was used to determine passenger arrival rates during different periods (morning, afternoon, and evening). An integer linear programming model was developed to minimize passenger waiting times. Data on vehicle types, capacities, travel cycles, and average passenger …

Implementation Of The Fourth Industrial Revolution Technologies In Tanzania’S Downstream Oil And Gas Industries, Vitalis John Mwinyi

Tanzania Journal of Engineering and Technology (TJET)

The advent of the fourth industrial revolution (IR4.0) has resulted in the digital transformation of multiple sectors of the economy due to the disruptive nature of the technologies driving the revolution. The technologies have already found their way into the oil and gas industries across the globe, especially in upstream, midstream, and downstream operations. However, the degree of implementation is not the same for these operations, considering the complexities involved, integrated process, the associated risk and investment cost, among others. This study aimed to establish the implementation level of IR4.0 technologies in the downstream operations. A survey method was employed …

Analysis Of Factors Enabling Organisational Governance Maturity For The Technical Audit Function In Tanzania, George C. Haule

Tanzania Journal of Engineering and Technology (TJET)

The study aimed to identify key factors contributing to Organisational Governance Maturity (OGM) of the Technical Audit Functions (TAF) in Tanzania.  The study employed a sequential approach as a research design.  The first step was to collect and analyse literature studies to identify factors enabling the OGM of the TAF.  Next, a questionnaire was administered to one hundred twenty-eight (128) respondents from seven (7) TAFs to rank the key enabling factors that were identified from the literature that influence the OGM of TAF in Tanzania.  Using data from a questionnaire administered to 128 respondents, a two-step strategy was employed to …