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Integrating Gis With Interim Payment Valuation In Road Construction Projects: A Conceptual Framework, Abdulrahman I. Iro, Juma M. Matindana, Julian Ijumulana Oct 2026

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 …


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 Oct 2026

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. Sep 2026

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 …


Mathematical Modelling For Optimizing Predator–Prey Networks In A Resilient Wildlife Ecosystem: A Systematic Literature Review, Thadei Damas Sagamiko Sep 2026

Mathematical Modelling For Optimizing Predator–Prey Networks In A Resilient Wildlife Ecosystem: A Systematic Literature Review, Thadei Damas Sagamiko

Tanzania Journal of Science

The resilience of wildlife networks hinges on the adaptability and stability of complex predator-prey interactions. Mathematical modelling offers a crucial approach for examining and optimizing these dynamics under biological invasions and environmental pressures. This systematic literature review (SLR) employs a bibliometric analysis approach to synthesize global research on mathematical models applied to predator-prey network optimization, with an emphasis on their ecological implications, computational approaches, and modelling strategies. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 50 peer- reviewed studies (2000–2025) were analyzed using the Scopus and Google Scholar databases. The study identifies classical models, such as the …


Modelling Acute Haemorrhagic Conjunctivitis In East Africa: An Integrated Approach To Transmission Dynamics And Outbreak Response Strategies, Geofrey Wingi Sikazwe Sep 2026

Modelling Acute Haemorrhagic Conjunctivitis In East Africa: An Integrated Approach To Transmission Dynamics And Outbreak Response Strategies, Geofrey Wingi Sikazwe

Tanzania Journal of Science

Acute hemorrhagic conjunctivitis (AHC) poses a significant global health risk, with the potential for rapid spread during outbreaks. For instance, a localized outbreak in Yunnan Province, China, recorded infection rates of up to 48%, illustrating how transmission can intensify under favourable epidemiological and environmental conditions. Existing mathematical models of AHC transmission overlook seasonal variations, a critical factor in epidemic spread. This study combines species distribution models (SDMs) and epidemiological modelling to analyse key drivers of AHC in East Africa. We use the SEIR type (Susceptible-Exposed-Infected-Recovered - incorporating waning immunity) framework with temperature-dependent infectivity rate as the key driver of an …


Silicon Nitride Thin Film Deposited By Plasma-Enhanced Chemical Vapour Deposition Technique For Various Device Applications, Anayesu Bariki Malisa Sep 2026

Silicon Nitride Thin Film Deposited By Plasma-Enhanced Chemical Vapour Deposition Technique For Various Device Applications, Anayesu Bariki Malisa

Tanzania Journal of Science

This work reports on silicon nitride (SiNx) thin film deposited by the Plasma-Enhanced Chemical Vapour Deposition (PECVD) technique. The film was characterized by Variable Angle Spectroscopic Ellipsometry (VASE) to obtain optical constants 𝑛, 𝑘 and thickness using the Cauchy layer built on the Lorentz oscillator model and the B-spline model. The determined optical band gap 𝐸𝑜𝑝𝑡𝑖𝑐𝑎𝑙 for direct transition was 3.2 𝑒𝑉 and that for indirect transition was 2.13 𝑒𝑉. Film characterization was performed by Fourier Transform Infra-Red spectroscopy (FTIR) at two different angles of incidence of 15 degrees to probe deep layers and 65 degrees (Brewster’s angle) to excite …


Assessment Of Inter-Observer Variability In Delineating High-Risk Clinical Target Volumes And Organs At Risk In Cervical Cancer Brachytherapy, Atumaini A. Makoba, Julius S. Chiuyo, Innocent J. Lugendo Sep 2026

Assessment Of Inter-Observer Variability In Delineating High-Risk Clinical Target Volumes And Organs At Risk In Cervical Cancer Brachytherapy, Atumaini A. Makoba, Julius S. Chiuyo, Innocent J. Lugendo

Tanzania Journal of Science

Achieving precise target volume delineation during cervical cancer treatment poses challenges due to several reasons, including difficulties in establishing the precise geometrical location of the gross target volume. Inter-observer variability in contouring anatomical structures poses a critical challenge to treatment consistency, delineation, and dosimetry accuracy. Volumetric and dosimetric records of 20 patients treated with gynecologic high-dose rate brachytherapy were analyzed to assess the interobserver variability between oncologists. Three radiation oncologists independently examined the organs at risk and high-risk critical organs on 20 computed tomography scans. The volumetric and dosimetric relationship between the contours delineated by radiation oncologists was described using …


Feasibility Of Acetylated Icacina Trichantha Oliv. Tuber Starch As Viscosity And Fluid Loss Control Agents In Water-Based Drilling Mud. A Comparative Assessment With Commercial Starch, Kennedy I. Ogunwa, Theresa O. Uchechukwu, Ozioma Achugasim, Leo C. Osuji, Onyewuchi Akaranta Sep 2026

Feasibility Of Acetylated Icacina Trichantha Oliv. Tuber Starch As Viscosity And Fluid Loss Control Agents In Water-Based Drilling Mud. A Comparative Assessment With Commercial Starch, Kennedy I. Ogunwa, Theresa O. Uchechukwu, Ozioma Achugasim, Leo C. Osuji, Onyewuchi Akaranta

Tanzania Journal of Science

The need for sustainable, non-food drilling fluid additives has prompted the feasibility assessment of acetylated Icacina trichantha tuber starch as a viscosity modifier and fluid loss control agent in water-based muds. Native starch was acetylated to obtain two derivatives (Degree of Substitution DS = 0.38 and 0.68) and characterized using FTIR, swelling power, and physicochemical analyses. Drilling mud performance was assessed through rheology, gel strength, filtration loss, sorptivity, and model fitting. Acetylation improved swelling and reduced gelatinization temperature. The optimal formulation, Mud-ITO-ACS2 (DS = 0.68), exhibited the most favorable performance, combining low plastic viscosity (6 cP vs 9 cP for …


Clustering Of Potable Water Sources In Rural Oyo State, Nigeria: Implications For Equitable Distribution And Sustainability, Adesola Adediran, Ibrahim O. Raufu Sep 2026

Clustering Of Potable Water Sources In Rural Oyo State, Nigeria: Implications For Equitable Distribution And Sustainability, Adesola Adediran, Ibrahim O. Raufu

Tanzania Journal of Science

Adequate and equitable access to potable water remains a major challenge in rural communities of Oyo State, Nigeria, with uncoordinated provision leading to widespread shortages. This study employs geospatial techniques to assess the spatial distribution of water supply sources across five purposively selected rural communities in Olorunsogo Local Government Area (OLGA). Geographic coordinates of boreholes, hand-dug wells, and other potable water sources were collected using a handheld Garmin GPS 76S device. Spatial analysis was conducted using ArcGIS, and Nearest Neighbour Analysis (NNA) was applied to evaluate the pattern of distribution. Results indicate a strong tendency toward clustering, with a Nearest …


Effect Of Acid Pretreatment On The Adsorption Of Phenol Red By Cellulose Isolated From Sandbox (Hura Crepitans L.): Kinetics, Isotherms And Thermodynamics, Muibat O. Alabi-Abass, Najeem A. Adesola Babarinde, Adeola A. Ibikunle, Nurudeen O. Sanyaolu Sep 2026

Effect Of Acid Pretreatment On The Adsorption Of Phenol Red By Cellulose Isolated From Sandbox (Hura Crepitans L.): Kinetics, Isotherms And Thermodynamics, Muibat O. Alabi-Abass, Najeem A. Adesola Babarinde, Adeola A. Ibikunle, Nurudeen O. Sanyaolu

Tanzania Journal of Science

The removal of synthetic dyes from wastewater remains an urgent environmental concern due to their persistence and toxicity. This study evaluates cellulose from Hura crepitans (HC) and its acid-modified form (AHC) for the adsorption of phenol red (PR) dye from aqueous solutions. The adsorbents were characterized using FTIR to identify functional groups responsible for dye binding, XRD to determine the crystalline structure, SEM to examine surface morphology, and BET/BJH analyses to measure surface area and pore distribution. Acid modification enhanced surface roughness, porosity, and the abundance of active functional sites, leading to improved adsorption efficiency. Optimal conditions were pH 9.0 …


Distribution Of Diagenetic Alterations In Lower Cretaceous Strata Of The Tanzanian Coastal Sedimentary Basin, Justina James Saroni Sep 2026

Distribution Of Diagenetic Alterations In Lower Cretaceous Strata Of The Tanzanian Coastal Sedimentary Basin, Justina James Saroni

Tanzania Journal of Science

The Lower Cretaceous sedimentary rocks of the Coastal Sedimentary Basin of Tanzania crop out in the Wami and Mandawa basins and are stratigraphically similar to the reservoir rocks hosting gas at Songo Songo. This study examines the relationship between facies and diagenetic processes in outcrops from the study area. Outcrop description and petrographic analysis by using optical and scanning electron microscopy (SEM) were used to identify facies and diagenetic alterations. Sixteen facies were identified, including siliciclastic facies: conglomerate (Gm), sandstones (St, Sp, Sm, Sh, Sr), siltstone and mudstone (Fm, Fl); and carbonate facies are packstone (Lsp, Lspc, Lspg, Lspo), grainstone …


Urban Spatial Development Control In Tanzania: Analysis Of Factors Influencing Gis Application Using Structural Equation Modelling (Sem)., Happiness Protas Mmanda, Nestory Yamungu Sep 2026

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 Sep 2026

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 …


Hydro-Chemical And Bacteriological Assessment Of Zanzibar Groundwater Resources, Subira Munishi, Andrew Kimati Sep 2026

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 …


Influence Of Silar-Deposition Cycle On The Tunable Optical Property Of Thallium Sulphide Thin Films Through Copper Doping And Variable Concentration, Qasim A. Adeniji, Surajudeen O. Azeez, Khadijat K. Babalola, Temitope O. Fowodu, Muhammad A. Salihu, Lateefah O. Adebayo Aug 2026

Influence Of Silar-Deposition Cycle On The Tunable Optical Property Of Thallium Sulphide Thin Films Through Copper Doping And Variable Concentration, Qasim A. Adeniji, Surajudeen O. Azeez, Khadijat K. Babalola, Temitope O. Fowodu, Muhammad A. Salihu, Lateefah O. Adebayo

Tanzania Journal of Science

The study reported the effect of SILAR-deposition cycle on the tunable optical property of Thallium Sulphide Thin films through copper doping and variable concentration. TlS:Cu thin films were prepared using successive ionic layer adsorption and reaction (SILAR) technique from the aqueous solution of thallium chloride (TlCl), copper (II) chloride dihydrate (CuCl 2 .2H 2 O), thiourea, and trisodium citrate (TSC) while ammonia (NH 3 ), triethanolamine (TEA) and ethylenediaminetetraacetate (EDTA) were used as pH adjuster and complexing agent, respectively. The detailed characterization of the Optical properties of the thin films were investigated using UV-Vis spectrophotometer. The optical results studies revealed …


Hydrogeophysical Assessment Of Groundwater And Saltwater–Freshwater Interface In A Quaternary– Neogene Coastal Aquifer, Kilwa Kisiwani Island, Southeast Tanzania, Simon R. Melchioly Aug 2026

Hydrogeophysical Assessment Of Groundwater And Saltwater–Freshwater Interface In A Quaternary– Neogene Coastal Aquifer, Kilwa Kisiwani Island, Southeast Tanzania, Simon R. Melchioly

Tanzania Journal of Science

This study aims to identify and explore new potential sites of groundwater resources using geophysical methods, and to demarcate the depth to the saltwater-freshwater interface. Kilwa Kisiwani Island is geologically covered mostly by Neogene and Quaternary alluvial sediments, sand and gravel. The geophysical techniques employed during the research include Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT), and Transient Electromagnetics (TEM). The Island has the potential for groundwater occurrences, but the layer with fresh water is shallow and thin. Out of the 18 VES sites, 2 (11%) points have shown non-potential, but the remaining 16 (89%) of the VES sites …


Simulated Versus Non-Simulated Imputed Data: A Comparison Of Handling Missing Data Techniques For Numerical Covariates, Rahibu A. Abassi, Rocky R.J. Akarro Aug 2026

Simulated Versus Non-Simulated Imputed Data: A Comparison Of Handling Missing Data Techniques For Numerical Covariates, Rahibu A. Abassi, Rocky R.J. Akarro

Tanzania Journal of Science

Missing data poses a great challenge in much research, and if not appropriately handled, can negatively impact the analysis and bias the results and study conclusions. This article assesses the performance of numerous methods used to impute missing data by using Root Mean Squared Error (RMSE) under various missing data proportions and two common missingness mechanisms, namely Missing at Random (MAR) and Missing Completely at Random (MCAR). RMSE values were used to judge the accuracy of imputation techniques using real data and across different simulation settings. The results showed magnitude of RMSE increased with increased proportions of missing data, regardless …


Aeroradio-Spectrometric Geothermal Analysis Of Abeokuta, Southwestern Nigeria, Fidelis O. Ogunsanwo Aug 2026

Aeroradio-Spectrometric Geothermal Analysis Of Abeokuta, Southwestern Nigeria, Fidelis O. Ogunsanwo

Tanzania Journal of Science

Weathered basement terrains of Precambrian origin are increasingly recognized as important targets for geothermal assessment and renewable energy exploration; yet systematic assessments integrating airborne radiometric data remain limited in south-western Nigeria. This study applies an aeroradio-spectrometric approach to evaluate and quantify the radiogenic heat production, geothermal gradient, and lithospheric heat flow associated with the diverse lithological assemblages of the Abeokuta area, southwestern Nigeria. The study area comprises of six lithological units, namely; biotite–garnet gneiss and schist, porphyroblastic gneiss, migmatite, pegmatite intrusions, and sedimentary successions of sand-clay-shale and sandstone–limestone. The concentrations of uranium (238U), thorium (232Th), and potassium (40K) were extracted …


Assessment Of The Radionuclide Concentration Levels Of Water And Sediments Along The Mara River, Gasper Kachenge, Abubakary Salama, Abdalah Kileo, Furaha Chuma Aug 2026

Assessment Of The Radionuclide Concentration Levels Of Water And Sediments Along The Mara River, Gasper Kachenge, Abubakary Salama, Abdalah Kileo, Furaha Chuma

Tanzania Journal of Science

For many years, several factors have impacted the water quality of the Mara River, including population growth, agricultural expansion, livestock keeping, mining, and industrial activities. These factors have intensified water pollution and climate change effects around the river. While previous studies have mainly focused on assessing heavy metal pollution risks on the Mara River, this study evaluates the concentration levels of radionuclides in boreholes, water, and sediments along the river and its tributaries. Naturally occurring radioactive materials, including 226Ra, ²³²Th, and ⁴⁰K, were evaluated. A high-purity germanium radiation detector (HPGe) with a coaxial detector system coupled with Gamma Vision software …


Monte Carlo Analysis Of Dose Distribution In Tumour And Adjacent Healthy Tissues During 192Ir Hdr Brachytherapy In The Presence Of Gold Nanoparticles, Damian P. Tippe, Innocent J. Lugendo Jun 2026

Monte Carlo Analysis Of Dose Distribution In Tumour And Adjacent Healthy Tissues During 192Ir Hdr Brachytherapy In The Presence Of Gold Nanoparticles, Damian P. Tippe, Innocent J. Lugendo

Tanzania Journal of Science

High dose rate (HDR) brachytherapy using 192Ir is an effective modality for cancer treatment; however, its therapeutic efficiency is often constrained by unintended radiation exposure to healthy tissues surrounding the tumour. Fortunately, the incorporation of high atomic number (Z) nanoparticles as radiosensitizers has emerged as a promising strategy to enhance tumour dose while sparing adjacent normal tissues. In this study, the dose distribution in tumour and nearby healthy tissues during 192Ir HDR brachytherapy was investigated in the presence of gold (Au) nanoparticles using Monte Carlo simulations based on the Geant4 toolkit. Radial dose distributions and anisotropy characteristics were analysed …


The Role Of Zinc Precursor Concentration In Modulating The Structural, Optical, And Electrical Properties Of Sol-Gel Derived Czts Thin Films, Justine John Tibaijuka Jun 2026

The Role Of Zinc Precursor Concentration In Modulating The Structural, Optical, And Electrical Properties Of Sol-Gel Derived Czts Thin Films, Justine John Tibaijuka

Tanzania Journal of Science

This study reports on CZTS thin films fabricated by sol–gel spin coating using zinc acetate dihydrate, copper acetate dihydrate, tin chloride, and thiourea dissolved in methanol with monoethylamine as a stabilizer. The films were annealed rapidly at 540 °C by using an RTP furnace. Results show the significant influence of zinc concentration on films’ properties with band gap evolution between 1.46 and 1.7 eV, along with high absorption coefficients exceeding 10⁴ cm⁻¹ in the visible range. Structurally, the films evolved from poorly crystalline at low Zn content to well- crystallized, (112)-oriented kesterite near stoichiometry. However, excessive Zn caused slight degradation …


Hydrogeochemical Characterization Of Groundwater In Fractured Crystalline Basement Aquifers In Dodoma, Central Tanzania: Implications On Water Quality For Domestic And Irrigation Applications, George J. Ishabairu, Simon R. Melchioly, Charles H. Kasanzu, Gabriel D. Mulibo Jun 2026

Hydrogeochemical Characterization Of Groundwater In Fractured Crystalline Basement Aquifers In Dodoma, Central Tanzania: Implications On Water Quality For Domestic And Irrigation Applications, George J. Ishabairu, Simon R. Melchioly, Charles H. Kasanzu, Gabriel D. Mulibo

Tanzania Journal of Science

Assessment of groundwater hydrogeochemistry characteristics of aquifers plays a vital role in establishing water quality status and its suitability for human and industrial use. The main objective of this research was to carry out hydrogeochemical characterization of groundwater and assess its impacts on water quality and spatial variability of groundwater geochemistry in Dodoma, Tanzania. The methods used include groundwater sampling, laboratory analysis to determine physico- chemical parameters and data processing to classify the groundwater hydrochemical facies. The results show that the average value for pH is 7.2, for electrical conductivity (EC) is 1108 µS/cm and for total dissolved solids (TDS) …


Linear Programming Model For Optimal Crop Allocation Under Varying Land Sizes In Pawaga, Tanzania, Mustapha Abbas Kiswanya, Seleman Ismail, Saul Mpeshe Jun 2026

Linear Programming Model For Optimal Crop Allocation Under Varying Land Sizes In Pawaga, Tanzania, Mustapha Abbas Kiswanya, Seleman Ismail, Saul Mpeshe

Tanzania Journal of Science

Farmers often rely on intuition when selecting crops, which can lead to suboptimal profits. In this study, we examine the optimal annual crop allocation under varying land sizes for farmers in Pawaga, Iringa District, Tanzania. A parametric linear programming (LP) model is developed to determine crop allocation combinations that maximise profit subject to land, labour, and capital constraints. Unlike conventional approaches that require separate models for different farm sizes, the proposed model accommodates land holdings ranging from 1 to 9 acres and integrates nine crop types within a single framework. Data were collected over three (3) agricultural seasons from extension …


Natural Radioactivity And Radiological Hazards In Sediments From The Lindi Coast, Indian Ocean, Tanzania, Viator Mujuni, Innocent J. Lugendo Jun 2026

Natural Radioactivity And Radiological Hazards In Sediments From The Lindi Coast, Indian Ocean, Tanzania, Viator Mujuni, Innocent J. Lugendo

Tanzania Journal of Science

The Lindi coast of the Indian Ocean, located in southeastern Tanzania, supports rich biodiversity and has recently experienced rapid growth in socio-economic activities such as fishing, mining, and oil and gas exploration. These activities may enhance levels of natural radioactivity in coastal sediments, potentially increasing radiation exposure to local populations. Therefore, monitoring radioactivity levels and estimating associated radiation doses in this region is important. In this study, thirty-six sediment samples were collected from twelve locations along the Lindi coast and analysed for naturally occurring radionuclides using high-purity germanium (HPGe) gamma-ray spectrometry. The activity concentrations of 226Ra, 232Th, and …


Concealed History Of Microplastic Pollution In The Msimbazi Estuary, Dar Es Salaam, Tanzania, Dativa J. Shilla Jun 2026

Concealed History Of Microplastic Pollution In The Msimbazi Estuary, Dar Es Salaam, Tanzania, Dativa J. Shilla

Tanzania Journal of Science

This study reconstructed the historical deposition of microplastics in sediments of the Msimbazi Estuary, Tanzania, using a radiometrically dated sediment core. Sediment chronology established using ²¹⁰Pb and the Constant Initial Concentration (CIC) model provided an approximately 83-year depositional record. The ²¹⁰Pb age model suggested marked temporal variability in sedimentation rates, with peaks around 1961, 1998, 2013, and 2015, potentially reflecting hydrological extremes and catchment disturbances. Anthropogenic microparticles were detected throughout most of the sediment core, with concentrations ranging from below detection limit (BDL) to 34 items kg⁻¹ dry weight (mean 8.5 ± 3.2 items kg⁻¹), and their abundance generally increased …


Hybrid Solar - Coal Thermal Energy System For Industrial Process Heat At Sayona Drinks Limited In Tanzania, Santos Kihwele, Elisha D. Bitesigirwe Jun 2026

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 …


On The Use Of Lorawan For Smart Fishing Applications In The Blue Economy Sector, Eva Shayo Jun 2026

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 …


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 Jun 2026

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 …


The Impact Of Gender Sensitization On Requirements Elicitation: A Controlled Experiment, Ruthbertha Kateule, Salome Maro, Leonard Peter Binamungu Jun 2026

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 Jun 2026

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% …