Digital Commons Network^™

Performance Dynamics Of Activated Carbon-Methanol Pair In Adsorption Refrigeration Systems, Ibrahim J. Mwasubila

Tanzania Journal of Engineering and Technology (TJET)

Adsorption refrigeration systems have shown potential for addressing the adverse effects of traditional compressor-based refrigeration systems. Adsorption refrigeration systems that utilise activated carbon and methanol demonstrate good performance, especially at temperatures below 0 °C. This combination significantly improves the cooling performance of the system, making it a dependable option for freezing applications. Despite having the potential to meet cooling demand and be eco-friendly, the adsorption refrigeration system has several drawbacks that hinder its commercialisation. This paper discusses the properties of the activated carbon methanol pair in the adsorption refrigeration system. The focus is on the desorption temperature, thermal stress, repeatability …

Strategies For Overcoming Product Certification Challenges Faced By Food Manufacturing Small And Medium Enterprises In Tanzania, Peresi M. Bulemo

Tanzania Journal of Engineering and Technology (TJET)

Small and Medium-sized Enterprises (SMEs) in Tanzania face significant regulatory challenges within bureaucratic, costly, and centralized environments. These challenges contribute to an increase in unregistered enterprises and substandard products in the market. This study aimed to address the challenges SMEs encounter in obtaining product certification to improve their product quality and market competitiveness. A mixed-methods approach was employed, combining qualitative and quantitative research through surveys, interviews, and document analysis, with respondents from the Tanzania Bureau of Standards (TBS), Small Industries Development Organization (SIDO), and SMEs in the food manufacturing sector. Data analysis was conducted using SPSS and JASP. Findings revealed …

Prospects Of Clean Cooking Energy In Africa - Transition Pathways And Implications, Joseph H. Kihedu Dr.

Tanzania Journal of Engineering and Technology (TJET)

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, …

Development And Experimental Validation Of A Non-Invasive Blood Group Detection System, Nurath K. Nurudini

Tanzania Journal of Engineering and Technology (TJET)

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 …

Towards Metrology 4.0 In Developing Countries’ Manufacturing Industries, Jailos Nzumile

Tanzania Journal of Engineering and Technology (TJET)

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 …

Comprehensive Review Of Sensible Thermal Storage Systems For Cooking Applications, Anna K. Shariishoy

Tanzania Journal of Engineering and Technology (TJET)

This paper reviewed the sensible thermal storage systems specifically designed for cooking applications. The review focuses on the characteristics of storage materials, their practical applications, and the overall performance of the systems. The review consolidated an array of experimental and numerical research published across various sources such as journals, conferences, books, online resources, and professional reports. A systematic review is used to reach the conclusion of this paper. Significant findings from this study include the wide range of storage capacities attained from small-scale systems that can store ~1–5 MJ of energy for a single meal to bigger systems that can …

Effects Of Cutting Conditions On Tool Temperature And Material Removal Rate In Turning Operations, Simon I. Marandu

Tanzania Journal of Engineering and Technology (TJET)

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 …

Mechanical Properties Of Pineapple Braided Fabric Reinforced Epoxy Matrix Composite Fabricated Via Vacuum-Assisted Resin Infusion Moulding, Bwire S. Ndazi

Tanzania Journal of Engineering and Technology (TJET)

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 …

Towards Effective Academia-Industry Collaborations: The Case Of Higher Learning Institutions In Tanzania, Fatuma S. Ikuja

Tanzania Journal of Engineering and Technology (TJET)

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 …

Towards Future Sustainable Infrastructure: The Role Of Technical Audit In Tanzania’S Public Works, George C. Haule

Tanzania Journal of Engineering and Technology (TJET)

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 …

The Impacts Of Renewable Energy Sources: A Review On Grid Inertia And Frequency Regulation, Sospeter Gabriel

Tanzania Journal of Engineering and Technology (TJET)

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 …

Calibration Of Measurement Tools In The Experimental Test Rig For Hydropower Performance Evaluation, Ombeni J. Mdee

Tanzania Journal of Engineering and Technology (TJET)

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 …

Review On Gas-To-Liquids Conversion Technology: Lessons From Case Studies And Potential Strategies For Implementation In Tanzania, Joseph H. Kihedu

Tanzania Journal of Engineering and Technology (TJET)

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. …

A Review Of Lithium-Ion Battery Capacity Fade Deceleration At Power Fluctuations In Renewable Energy Systems, Isaac Gwayi

Tanzania Journal of Engineering and Technology (TJET)

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 …

Design And Control Of A Versatile Modular Soft Robotic System With Integrated Resource Sharing And Self-Reconfiguration Capabilities, Joshua Knospler

Theses and Dissertations

Modular, self‑reconfigurable soft robots promise unprecedented versatility by combining the compliance of soft materials with the adaptability of modular architectures. This thesis presents an integrated system of pneumatic, bending-type soft actuator modules. Modules are compact and fully equipped with tunable magnetic and electromechanical connections for low‑power attachment and detachment and a novel power-air-communication (PAC) connector for seamless sharing of electricity, compressed air, and digital signals. This work examines two representative assemblies: ManusBot, a pinching gripper, and TendrilBot, a versatile linear configuration for various tasks. Their grasping performance, variable stiffness, and radial support capabilities are characterized. A magnetic interlock and an …

Towards Future Sustainable Infrastructure: The Role Of Technical Audit In Tanzania’S Public Works, George C. Haule

Tanzania Journal of Engineering and Technology (TJET)

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 …

Assessment Of Digital Solutions For Conformity Assessment Of Legally Controlled Measuring Instruments In Tanzania, Faraja Nyoni

Tanzania Journal of Engineering and Technology (TJET)

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 …

Optimisation Of Astatic Controllers In Automatic Control Systems, Isamiddin Xakimovich Siddikov, Dilnoza Maxamadjanovna Umurzakova

Chemical Technology, Control and Management

This article examines the influence of various factors on the efficiency of optimizing station controllers in automatic control systems. The main focus is on minimizing static errors and improving the reliability of controllers. Optimization methods for PID and PI²D controllers are discussed, including the use of modern approaches such as genetic algorithms. The necessity of compromise solutions to achieve high-quality system responses to various impacts is investigated. It was also suggested that there is a need for an integrated approach to setting up controllers in order to increase their reliability and flexibility in conditions of dynamically changing processes. …

Advancements In Refreshable Braille Display Technology: A Comprehensive Survey, Maryam Etezad, Rajeev Joshi, Franceli L. Cibrian

Engineering Faculty Articles and Research

This paper provides a comprehensive mapping literature review of the advancements in refreshable Braille display (RBD) technology, which employs dynamically movable pins or dots to render Braille characters for individuals with blindness and visual impairment. This literature review, which includes 96 papers, aims to summarize the current evidence on six distinct types of RBDs: piezoelectric, electromagnetic, electroactive polymer (EAP), pneumatic, shape memory alloy (SMA), and microfluidic technologies. For each type, we discuss the underlying mechanisms, alongside the current trends and research opportunities. This comparative analysis aims to inform the selection of appropriate RBD technology based on specific user needs and …

The Dynamics Of Word-Of-Mouth Marketing: An Agent-Based Modeling Approach To Message Credibility And Consumer Engagement, Ali Nasirzonouzi, Carlos Gershenson

Northeast Journal of Complex Systems (NEJCS)

Word-of-mouth (WOM) marketing is a critical factor in the dissemination of information and adoption of products in social networks. This paper investigates the impact of two important factors message credibility and consumer engagement on WOM adoption dynamics using agent-based modeling (ABM). This study proposes a simple qualitative model to investigate how these factors influence adoption rates through both broadcast communication and peer-to-peer influence by simulating interactions on a spatially clustered network.

The findings show that increased message credibility significantly boosts adoption, achieving a balance between broadcast and social mechanisms. Also, consumer engagement primarily affects the adoption mechanism, shifting the effect …

Store-By-Voice: A Voice-Controlled Putaway And Stocktaking System, Thorsten Schmidt, Heiner Ludwig, Mathias Kühn

International Material Handling Research Colloquium

No abstract provided.

Development Of Mechanical Transfer Station For Automated Transport Robots, Stefan Galka

International Material Handling Research Colloquium

No abstract provided.

Daily Shipment Planning Using Generative Ai: A Customized Gpt-Driven Approach, Banu Yetkin Ekren

International Material Handling Research Colloquium

No abstract provided.

Reusing Materials In The Aerospace Industry, Lama Alanazi, Burtegeljin Gombosuren, Byhalia Jewett

Beyond: Undergraduate Research Journal

This research explores the material recycling methods used by the aerospace industry, particularly in comparison to the reusability of aerospace materials and with the objective to find uses for recycled materials from aircraft. Through an analysis of various other material mitigation methods, it is apparent that the physical degradation of materials after they go through recycling processes and the cost of recycling are the most prominent issues holding the aerospace industry back from being able to recycle aircraft up to 100%. From a comparison of physical characteristics of materials after reprocessing, several materials were found to meet industry standards, while …

A Yolo-Based Deep Learning Approach For Vibration-Based Rotating Shaft Imbalance Detection, Abdelhameed Zayed Dr., Ali Siam Dr.

Journal of Engineering Research

One of the prevailing causes of vibrations in machines is rotor imbalance. Rotor balancing can be used to fix the majority of rotating machinery issues. When it comes to high-speed running equipment, even a slight imbalance can lead to serious issues and decrease the operational efficiency of rotating machinery. This work proposed a deep learning approach for the detection of binary and multiclass imbalance in rotating shafts. A YOLOv11 model-based approach is developed to detect imbalance and identify unbalanced rotor positions. To precisely identify unbalanced positions, this method trains the YOLOv11 model using numerous sets of measured response data and …

Impact Of Gamma-Ray Dose On Indoor Visible Light Communication Link Performance: A Geant4 Study, Fayza Mohamed Elamrawy, Adel Mohamed Ismail, Hossm Kasem Prof, Salah Khamis Prof, Ahmed Abdelaziz Youssef Prof

Journal of Engineering Research

This research presents an extended performance analysis of an indoor Visible Light Communication (VLC) system by integrating experimental results with advanced GEANT4 simulations. Building on a prior empirical study that evaluated different LED configurations and photodetectors, this work explores critical environmental and spatial parameters that influence VLC efficiency and reliability. Parameters such as wall reflectivity, emission angles, photon energy, and photon travel time are systematically analyzed using a validated GEANT4 simulation framework. The results confirm the strong impact of narrow emission angles and high wall reflectivity on detection performance, while also highlighting the importance of time delay modeling in high-fidelity …

Evaluating The Role Of Building Information Modeling (Bim) In Minimizing Delays And Reducing Costs In Construction Projects, Hussein Elsayed Mohamed Ismail, Mohammad Ahmad Mohammad Abdulhadi

Journal of Engineering Research

The implementation of Building Information Modeling (BIM) as a construction industry technology delivers extensive effects on project duration and financial management. This investigation examines BIM as a technology specifically designed to cut down construction project delays and decrease expenditures. The scholarly review of existing research material through a secondary approach allows this study to identify BIM's major value contributions.

The implementation of BIM technology enables project schedules to reach improved accuracy which results in a reduction of project delays by 15-25% because of its automation features and effective clash detection and real-time coordination benefits. The application of building information modeling …

Multi-Modal Covid-19 Detection Using Cough Sounds And Medical Information With Attention-Enhanced Deep Learning, Mohamed Talaat Saidahmed, Reda Elbasiony, Marwa Reda Bastwesy, Asmaa Aly Hagar

Journal of Engineering Research

The COVID-19 pandemic has highlighted the need for fast, non-invasive, and cost-effective diagnostic tools. Cough sounds, as a prominent symptom of respiratory diseases, present a promising modality for automated COVID-19 detection. In this study, we propose a novel multi-modal deep learning framework for COVID-19 detection that leverages cough sounds and patient-specific medical information. Our approach extracts two types of acoustic features—Mel-Frequency Cepstral Coefficients (MFCCs) and Mel spectrograms—and integrates them with clinical metadata to improve diagnostic ac-curacy. The MFCC branch employs 1D convolutional layers followed by Efficient Channel Attention mechanism. The Mel spectrogram branch utilizes ResNet-50 combined with ECA to capture …

Mutual Coupling Impedance Effect On Ris-Assisted Terahertz Communication, Radwa A. Roshdy Dr., Hossam M. Kasem Prof., Mohammed A. Salem Dr.

Journal of Engineering Research

Terahertz (THz) communication based on reconfigurable intelligent surfaces (RIS) is a promising technology in future wireless networks, with the capabilities of ultra-high data rates and energy-efficient beam communicating. Nevertheless, the mutual coupling impedance of the closely spaced RIS reveals the inefficacy in existing channel estimation schemes, while it is usually ignored in the literature. In this paper, we fill this gap by developing an EM-compliant channel model that integrates mutual coupling explicitly for RIS-assisted THz systems. We evaluate the performance of mutual impedance-induced influence to the accuracy of the root mean square error (RMSE), which is considered as a pivotal …

Performance Enhancement Of Ev Drive System Under Open-Phase Fault Using Reinforcement Learning With Mpc, Ahmed M. Hassan, Mohammed E. Metwally Dr.

Journal of Engineering Research

Improving the operation of electric vehicles (EVs) under fault is a very important subject because it increases their ability to operate in case of an emergency. This paper proposes a fault-tolerant control methodology for an EV drive system under open phase fault (OPF). The 5-ph interior permanent magnet synchronous motor (IPMSM) is employed in the drive system because it has several merits, such as high efficiency and reliability. The proposed technique is based on utilizing a reinforcement learning (RL) control algorithm, based twin-delayed deep deterministic policy gradient (TD3) algorithm, to operate the motor at maximum torque per ampere under OPF. …