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Full-Text Articles in Transportation Engineering

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 …


Optimization Of Vehicle Mix For Three-And Four-Wheel Passenger Transportation System In Nigeria, Omotunde A. Muyiwa, Hamid A. Jimoh, Kolawole T. Oriolowo Apr 2026

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 …


The Role Of Internal Factors On Vehicular Mobility, Aziz Mdimi Jun 2025

The Role Of Internal Factors On Vehicular Mobility, Aziz Mdimi

Tanzania Journal of Engineering and Technology (TJET)

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 …


Comparative Analysis On Design Error Risks In Design-Bid-Build And Design-Build Construction Approaches, Eradius Edward Rwakarehe Apr 2025

Comparative Analysis On Design Error Risks In Design-Bid-Build And Design-Build Construction Approaches, Eradius Edward Rwakarehe

Tanzania Journal of Engineering and Technology (TJET)

This study was conducted to compare design errors risk in Design-Bid-Build (DBB) (traditional) and Design-Build (DB) methods in building projects. Several construction projects under both DB and DBB method were reviewed. On most of construction projects under DB method, it was found that there were over supply of floor area due to different reasons. Also, it was found that, clients’ requirements were changed during project execution, which resulted into change on schedule, contract value and project quality. It was also revealed that in most cases, designs were in accordance with the clients’ requirements as submitted earlier but during construction clients …


Development Of A Microcontroller-Based Intelligent Traffic Light Control System For Vehicular Movement In T-Junctions, Frederick O. Ehiagwina Apr 2025

Development Of A Microcontroller-Based Intelligent Traffic Light Control System For Vehicular Movement In T-Junctions, Frederick O. Ehiagwina

Tanzania Journal of Engineering and Technology (TJET)

This research is devoted to the issue of regulating traffic congestion in major cities using light-dependent resistors coupled with the PIC16F877A microcontroller. This study proposes an intelligent traffic control system for T-Junctions, utilizing sensing and control to optimize traffic flow through dynamic phase adjustments and congestion reduction, enabled by a microcontroller-based decision-making system. The proposed system reduces traffic congestion, automates control, and enhances safety, minimizing accidents and lowering infrastructure costs. Under simulated environment, it demonstrates an average response time of 50 ms and achieves 99% accuracy in displaying the correct countdown. Finally, the number of state transitions handled per minute …


Modeling The Influence Of Internal Factors On Vehicular Mobility Performance, Aziz Mdimi Aug 2024

Modeling The Influence Of Internal Factors On Vehicular Mobility Performance, Aziz Mdimi

Tanzania Journal of Engineering and Technology (TJET)

Traffic mobility is significantly influenced by road conditions and the internal factors governing vehicular performance. Internal factors play a crucial role in vehicular mobility, influencing vehicles operate and performance. While existing vehicular mobility models primarily address external factors, external factors such as governor, engine, gear train and differential unit remain underexplored. This study formulates a comprehensive model to address this gap, focusing on the internal components that affect vehicular mobility. The proposed model employs both analytical and numerical methods to derive transfer functions for these subsystems using Matrix Laboratory (MATLAB), aiming to capture the dynamic behavior of vehicles under various …


Modelling Monthly Rainfall Of Calabar, Nigeria Using Box-Jenkins (Arima) Method, Francis Ogbozige Jun 2022

Modelling Monthly Rainfall Of Calabar, Nigeria Using Box-Jenkins (Arima) Method, Francis Ogbozige

Tanzania Journal of Engineering and Technology (TJET)

Rainfall has both positive and negative effects on human activities hence, correct prediction of the period of occurrence is very essential. However, the traditional method of predicting months of heavy rainfall is gradually fading out as irregular rainfall pattern is been experienced in most regions of the world. The rainfall pattern in Calabar city in Southern Nigeria has been reported in past literatures of being irregular. Hence, this research applied the Auto-Regressive Integrated Moving Average (ARIMA) also known as Box-Jenkins method to model the rainfall pattern of Calabar. This was achieved by subjecting 50years monthly rainfall (1971 – 2020) to …


Resilient Modulus Of Siliciclastic Unbound Granular Materials Under Repeated Wheel Loading, Siya Rimoyi Feb 2022

Resilient Modulus Of Siliciclastic Unbound Granular Materials Under Repeated Wheel Loading, Siya Rimoyi

Tanzania Journal of Engineering and Technology (TJET)

The Resilient Modulus (Mr) is a fundamental material property input in modern Mechanistic-Empirical (M-E) pavements structural design. Empirical pavement design methods have been in use over a long period during which large databases of four- days-soaked California Bearing Ratio (CBR) values at or near the Maximum Dry Density have been generated in the strength assessments for Unbound Granular Materials (UGMs). In the adoption of the M-E design approach researchers have so far attempted with various degrees of success to develop models to derive resilient modulus from the conventional CBR-based databases. This study provides an extensive laboratory experimental study to investigate …


Prediction Of Four-Days Soaked California Bearing Ratio (Cbr) Values From Soil Index Properties, Pascal Ambrose, Siya P. Rimoy Dr Jul 2021

Prediction Of Four-Days Soaked California Bearing Ratio (Cbr) Values From Soil Index Properties, Pascal Ambrose, Siya P. Rimoy Dr

Tanzania Journal of Engineering and Technology (TJET)

California Bearing Ratio (CBR) laboratory testing is the conventional method for determining soaked strengths of pavement subgrades. The test requires careful preparation of soil samples followed by four days of water soaking before penetrating the samples using a standard plunger at prescribed rates to set depths. When the number of samples becomes large the determination of soaked CBR values becomes cumbersome as the test is laborious and time consuming. This study aimed at establishing an alternative way of determining soaked CBR by developing a model that would be used for estimating soaked CBR of fine- and coarse- grained soils without …


Direct Predictive Speed Control Of Salient Pmsm Drives In Constant Torque And Constant Power Regimes For Electric Vehicles Applications, Francis Mwasilu Dec 2020

Direct Predictive Speed Control Of Salient Pmsm Drives In Constant Torque And Constant Power Regimes For Electric Vehicles Applications, Francis Mwasilu

Tanzania Journal of Engineering and Technology (TJET)

A direct speed control of salient permanent magnet synchronous motor (PMSM) drives in constant torque and constant power regimes for electric vehicles applications is presented. The proposed speed control scheme is derived from model predictive control approach where both rotor speed and stator current are formulated in a single objective function that is periodically computed to attain the PMSM drive optimum switching states. The dynamic model of the PMSM intrinsically encompasses the unknown disturbance, which should be rejected for high-performance speed control especially in transient conditions. Consequently, the extended modified augmented state Kalman filter (ASKF) is incorporated in the proposed …


Prediction Of Haul Units’ Requirements For The Open Pit Mines Operating Towards Closure, Bartłomiej Skawina Dec 2019

Prediction Of Haul Units’ Requirements For The Open Pit Mines Operating Towards Closure, Bartłomiej Skawina

Tanzania Journal of Engineering and Technology (TJET)

The determination of haul units is one of the important steps in the equipment selection process. The process should aim at minimizing the operational costs and create an optimal match for the haulage system. When open pit mines operating towards closure, reducing the operational costs results in significant gaining, and the savings can be used to implement some of the closure plans. In this paper, the prediction of haul units for an open pit mine which operates towards the final pit limit was analysed using discrete event simulation and multiple linear regressions. The result shows that the changes in production …


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

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

Tanzania Journal of Engineering and Technology (TJET)

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


Modelling Transport Of Nitrogen Compounds In Geita Wetland Along Mtakuja River, Ezrael Masawe Jun 2018

Modelling Transport Of Nitrogen Compounds In Geita Wetland Along Mtakuja River, Ezrael Masawe

Tanzania Journal of Engineering and Technology (TJET)

The impacts of excessive nitrogen loading to streams in a watershed occur in the receiving waters such as rivers at the outlet of the watershed. To quantify the impacts of land use and management practices on the nitrogen loading at the watershed outlet, simulation models are needed that can both predict the nitrogen loading at the edge of individual fields and predict the fate of nitrogen as it moves through the river network to the watershed outlet. This paper presents the results of a model analysis for describing the processes governing transformations and transport of nitrogen compounds (NO3-N and NH4-N) …


Universal Design Of Transportation Systems: A Case Study Of Access And Mobility Of People With Disabilities At Selected Intersections In Dar Es Salaam, Nurdin Mushule Dec 2010

Universal Design Of Transportation Systems: A Case Study Of Access And Mobility Of People With Disabilities At Selected Intersections In Dar Es Salaam, Nurdin Mushule

Tanzania Journal of Engineering and Technology (TJET)

The pedestrian facilities at intersections must be usable by pedestrians of all ages and capabilities. Intersections in particular must be designed to safely accommodate pedestrians of all ages and physical and mental abilities. Often, however, intersection designs fail to accommodate people with visual and mobility disabilities. In this regard, for pedestrians with disabilities, intersections can prove to be a challenge. Some of those challenges include provision of insufficient pedestrian clearance time due to use of inappropriate design pedestrian speed. Most importantly, the required facilities to enable People With Disabilities (PWD) to use the intersection without hindrance may be missing. Obstacles …


Calibration Of Hdm-4 For Use In Pavement Management Systems (Pms), Nurdin Mushule Dec 2009

Calibration Of Hdm-4 For Use In Pavement Management Systems (Pms), Nurdin Mushule

Tanzania Journal of Engineering and Technology (TJET)

One of major problems of road management in developing countries is the lack of decision making tools for preparing road maintenance programmes. This results in poor resource allocation and poor utilisation of existing assets. Pavement management systems (PMS) have been developed around the world in order to assist with the pavement management process in a co-ordinated and systematic manner. Some developed countries have derived pavement performance models that are suited to local conditions by setting up long term pavement performance studies. Conversely, most developing countries do not have the resources required to set up similar large-scale field experiments. However, validation …


The Influence Of Branches In The Performance Of Power-Line Communication Systems That Use Mc-Coma With Reed Solomon Coding, Emmanuel Felix Dec 2009

The Influence Of Branches In The Performance Of Power-Line Communication Systems That Use Mc-Coma With Reed Solomon Coding, Emmanuel Felix

Tanzania Journal of Engineering and Technology (TJET)

Power-line network is proposed as an infrastructure for Information and Communications Technologies (ICTs)
services provision. However, there are a number of factors that contribute greatly to power-line communication performance degradation. These include number of branches that can be added or removed from the power- line network, lengths of the branch lines, loading etc. It has been pointed out that the number of branches is one of the factors that affects power-line performance to a certain extent. In this paper the influence of number of branches on the performance of Broadband Power-line communication (BPLC) that uses MC- CDMA modulation scheme with …


Auditing Of Traffic Signs And Road Markings In Dar Es Salaam City, Hannibal Bwire Jun 2009

Auditing Of Traffic Signs And Road Markings In Dar Es Salaam City, Hannibal Bwire

Tanzania Journal of Engineering and Technology (TJET)

This study examines the efficacy of the traffic signs and road markings in Dar es Salaam City. The study focuses on the availability and conditions of traffic signs and road markings in some selected roads in the city. Auditing of traffic signs and road markings is carried out as one of the means of promoting road safety and improving road capacity in the city. The auditing procedure involved field studies through the use of traffic signs/markings checklists and ranking of road stretches according to the availability and conditions of traffic signs observed for improvement prioritization in case of financial constraints. …


The Limnogeology Of The Lakes Sagara And Nyamagoma, Hudson Nkotagu Jun 2008

The Limnogeology Of The Lakes Sagara And Nyamagoma, Hudson Nkotagu

Tanzania Journal of Engineering and Technology (TJET)

The present study focuses on the limnogeological aspects of the lakes Sagara and Nyamagoma within the Malagarasi Wetland Ecosystem. Abiotic parameters from water and sediment samples were determined during the dry and wet seasons using appropriate gears and methods. The data show variation of the abiotic parameters in both lakes from the water surface to the bottom. Lake Nyamagoma is less turbid (0.7-24 NTU) than Lake Sagara (25 to 65 NTU). The water transparency was also high at Lake Nyamagoma (0.75-1.5 m) thus supporting the observed turbidity trend. The physical chemical changes may be attributed to processes such as cooling, …


Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor Jun 2006

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …


Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo Jun 2004

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.


Potential For Use Of Sand In Road Construction In Dar Es Salaam And Coast Regions, Mfinanga A Dec 2002

Potential For Use Of Sand In Road Construction In Dar Es Salaam And Coast Regions, Mfinanga A

Tanzania Journal of Engineering and Technology (TJET)

Coarse aggregates for use in road construction in Dar es Salaam and Coast regions are becoming increasingly scarce and expensive while sand, which is cheaper, is readily available in the two regions. This research aimed at evaluating the possibility of using quarry sands in the two regions as a major constituent material in bituminous road pavement layers. First, the use of sand in sand-bitumen bases for low and medium trafficked roads was studied. The study then continued with the preliminary evaluation of the possible use of the sands in hot rolled asphalt mixes. Results show that Mbagala sand can be …


Sustainable Data Acquisition Methods For Road Maintenance Management In Developing Countries, N. K.M. Mushule Dec 2002

Sustainable Data Acquisition Methods For Road Maintenance Management In Developing Countries, N. K.M. Mushule

Tanzania Journal of Engineering and Technology (TJET)

Whilst it may be argued that manual methods of pavement data collection are subjective, unsafe, involve high personnel costs and have low repeatability, the initial costs of acquiring automated systems coupled with the technology required to operate and maintain them can be prohibitive for most developing countries. Moreover, automatic measurement of surface distress has proved to be a difficult challenge to instrument designers. In many cases, manual methods are the only ones that can be employed. A research project was carried out to design a sustainable data collection scheme for network level management system for developing countries. A simple procedure …


Mathematical Modelling Of Road Bumps, E. S. Massawe Dec 1999

Mathematical Modelling Of Road Bumps, E. S. Massawe

Tanzania Journal of Engineering and Technology (TJET)

In this paper, a general mathematical model that may be used for construction of a road bump on an inclined road is developed. It is shown that if the parameters for the inclination are set to zero, the resulting model reflects the special case of a flat road. Existing experiences are briefly highlighted and a case study was done on different locations along the University Road to demonstrate the developed model.


Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna Dec 1999

Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna

Tanzania Journal of Engineering and Technology (TJET)

Vibration is one of the techniques employed in the determination of dynamic properties of fruits and vegetables. It entails generation of a mechanical or acoustic vibrational signal which is propagated through the flesh of the agricultural material. A transducer is either attached or held close to the specimen to monitor the propagation of the signal through the specimen. The manner in which the signal is transmitted through the material is analyzed, and the dynamic properties of the specimen which relate to its firmness or its internal being are derived. The technique has been around for the past 30 years or …


Effect Of Reduced Plate Width On The Structural Behaviour Of A Triangularly Folded Plate Barrel Vault, S Manyele Jul 1993

Effect Of Reduced Plate Width On The Structural Behaviour Of A Triangularly Folded Plate Barrel Vault, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

Various methods of analysis have been employed to predict the  structural behaviour of the Triangularly Folded Plate Barrel  Vault, with conflicting results. A review of past analytical  and experimental investigations carried out on the structure  show that theoretical analysis based on a smaller effective  width rather than the overall plate width is capable of closely  predicting the deflection behaviour of the structure.  This paper presents an experimental study of the behaviour of  a triangularly folded plate barrel vault with physically reduced  plate width.  It is found that physical reduction of the plate width to  correspond to ‘theoretical’ effective width weakens …