Industrial Engineering Commons^™

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 …

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 …

Nanostructured Cathode Catalysts For Aem Electrolysis: From Catalyst Design To Degradation And Hydrogen Dynamics, Yamini Kumaran

Electronic Theses & Dissertations (2024 - present)

Anion exchange membrane water electrolysis (AEMWE) presents a promising pathway toward cost-effective and sustainable hydrogen production by integrating the chemical robustness of alkaline systems with the compact, zero-gap design of proton exchange membrane electrolyzers. However, the widespread implementation of AEMWE is limited by the availability of highly active and durable platinum-group-metal (PGM)-free catalysts and by an incomplete understanding of their degradation behavior under realistic operating conditions.

This dissertation focuses on the development, characterization, and mechanistic investigation of nanostructured MoNi₄–MoO₂-based electrodes for efficient and stable hydrogen generation under alkaline and membrane-integrated environments. MoNi₄–MoO₂ nanorods …

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 …

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 …

Fuzzy Logic-Based Decision Support System For Adoption Of Industry 4.0 Predictive Maintenance By Manufacturing Industries, Fred E. Peter

Tanzania Journal of Engineering and Technology (TJET)

In the context of Industry 4.0, predictive maintenance enhances operational efficiency by optimizing processes, minimizing downtime, and improving cost-effectiveness. However, implementing predictive maintenance requires a systematic approach due to its complexity. This study collected expert input from 15 food and beverage manufacturing industries located in Dar es Salaam, Tanzania, using a purposive sampling technique. Six representatives were selected from each industry, and their opinions were analyzed using MATLAB 7.6 through a fuzzy logic inference system. The analysis focused on key factors influencing Industry 4.0 technology adoption for predictive maintenance, including adoption intention (strategic decision, equipment data, perceived benefit) and perceived …

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 …

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 …

Wet Gas Metering Performance Using Conventional Flow Measurement Devices, Vitali Mwinyi

Tanzania Journal of Engineering and Technology (TJET)

The demand for and production of natural wet gas from wells has significantly risen in recent years. Although natural gas liquids hold substantial value in the oil and gas market, their presence in wet gas adversely affects gas metering, leading to overreading during measurement. A comprehensive study has been undertaken to formulate and enhance correlations for rectifying overreading in wet gas metering. Nevertheless, most current correlations are designed for horizontal configurations of traditional meters. Mitigating this constraint is crucial to consider the impact of gravity on pressure loss in vertically oriented systems. This study seeks to evaluate the efficacy of …

Evaluation Of Thermal And Emission Performances Of Briquettes Produced From Carbonized Corn Cob And Corn Husk, Karina S. Motani

Tanzania Journal of Engineering and Technology (TJET)

The Mozambican agro-industrial sector relies heavily on various crops, with maize being the most significant. During processing, substantial waste is generated, which is often discarded as organic matter or burned, contributing to environmental pollution and the loss of potential energy resources. This study evaluated the thermal and emission performance of briquettes made from carbonized corn cob (CCC) and carbonized corn husk (CCH), using cashew nut skin as a binder for clean cooking applications. The briquettes were assessed against firewood and charcoal as control fuels, focusing on several energy performance parameters: water boiling time (WBT), combustion index (CI), thermal efficiency (TE), …

Predicting The Influence Of Aggregate Size And Distribution On Cementitious Concrete Properties: A Review, Innocent J. Macha

Tanzania Journal of Engineering and Technology (TJET)

Cement concrete has been in use for centuries as one of the primary construction materials. Its demand in the construction industry is expected to continue for several centuries before the full development of alternative products. However, one of the main areas of research interest is understanding how its constituents can be tailored to make its properties predictable to reduce risks associated with structural failures, reconstruction and reduced durability. These hindrances associated with cementitious concrete result from several attributes, including constituent material characteristics, mixing ratios and workmanship. Understanding the predictability of cement concrete properties requires computer modelling tools to provide reliable …

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 …

Root Cause Analysis Of Performance Degradation For An Xyz Thermal Power Plant In Tanzania, Simon I. Marandu

Tanzania Journal of Engineering and Technology (TJET)

Thermal power plants in Tanzania have been experiencing performance degradation, typically arising from component and subsystem failures, which contribute to power system instability and unreliability. This paper presents a case study of the root causes of performance degradation of an XYZ thermal power plant. The study was conducted by reviewing plant documentations, including maintenance and operational data logbooks, and by standardising the approach through the adoption of ISO 14224:2016 for maintenance and reliability data exchange. Data evaluation was carried out using principal component analysis and scree plot analytical techniques to enhance the depth and accuracy of root cause identification. Additionally, …

Optimizing The Processing Temperature For Synthesis Of Silver Nanoparticles Within Cellulose-Wool Keratin Supramolecular Matrix Using Butylmethylimmidazolium Chloride Ionic Liquid, Ngesa E. Mushi

Tanzania Journal of Engineering and Technology (TJET)

To date, the synthesis of silver nanoparticles on the surface of cellulose and wool keratin biopolymer, while dissolved in ionic liquid, is attractive because of its biomedical potential. However, the optimal processing temperature for the nanoparticle formation is unclear. The previously reported temperature of approximately 120°C gives unpredictable results. The current study employs a combination of 50% cellulose and 50% keratin, along with 69 mg of silver chloride, in Butylmethylimidazolium Chloride BMImCl ionic liquid, using a single-pot process to produce a supramolecular film via non-derivatized mechanochemical interactions. The primary objective is to experimentally establish the processing temperature to achieve stable …

Cellulose Recovery From Waste Denim Fabrics Through Indigo Vat Dye Reduction And Spandex Dissolution, Tito N. Venance

Tanzania Journal of Engineering and Technology (TJET)

This study addresses environmental conservation by tackling end-of-life management for post-consumer denim garments through the recycling of cotton fibres from waste denim. The purification process involved dithionite reduction of vat dyes in the presence of an alkali followed by selective dissolution of spandex using N,N-dimethylformamide (DMF). Optimal conditions for dye removal were determined at 90°C for 120 minutes with sodium hydroxide at 25 g/L, sodium dithionite at 6 g/L and PVP at 4.5 g/L, while spandex extraction was achieved using a 5% DMF solution at 70°C for 4 hours. Ultraviolet (UV)-vis spectrophotometric analysis indicated a significant increase in whiteness (DL*). …

A Fuzzy Based Framework For Sustainable Technology Selection In Small-Scale Gold Mining Operations, John M. Kafuku

Tanzania Journal of Engineering and Technology (TJET)

Small-scale gold mining (SSGM) operations in Tanzania has been operating inefficiently due to inadequate mining processing technologies, poor working tools, lack of enough capital, and insufficient electricity. Despite the efforts made by different stakeholders in boosting the sustainability of SSGM yet the sector has not reached the expected goal. This paper proposes a framework for appropriate technology selection to help small scale gold miners in evaluating various gold mineral processing technologies. The framework utilizes the fuzzy logic set theory for technology evaluation and selection. The developed framework for technology selection upon validation provided results that technology adequacy of more than …

Assessment Of Factors Contributing On Early Rotting Of Chromated Copper Arsenate Treated Utility Power Distribution Wood Poles In Tanzania, Innocent J. Macha

Tanzania Journal of Engineering and Technology (TJET)

The study aimed to assess the factors contributing to the premature decay of Chromated Copper Arsenate (CCA) treated utility power distribution wooden poles in Tanzania. Deteriorated poles samples from various regions in Tanzania were analyzed using handheld X-ray spectrometry to quantify the retention of CCA preservative chemicals. The ages of these poles were estimated based on annual growth rings. The findings indicated that premature failure of CCA treated wooden poles is attributed to an imbalance in the chemical composition of the preservative solution. The study found that CuO retention in most samples ranged between 10-18 kg/m3, significant lower that the …

Principles And Models Of Construction Of Linear Motion Actuators With Holonomic Structure For Intelligent Robot Movement, Matyokubov Nurbek Rustamovich, Temurbek Omonboevich Rakhimov, Yusupov Bekmurod Bayotovich

Chemical Technology, Control and Management

This article is devoted to the principles and models of building linear motion actuators with holonomic structure for the movement of intelligent robots. Also, the classification of the elements of the linear movement performance according to their interconnections and technical characteristics, taking into account their physical characteristics, was seen. A morphological matrix of the construction of holonomic structured linear motion performance elements based on the classification according to the considered technical specifications is presented. The given morphological matrix of linear motion actuators serves to develop new actuators for intelligent mechatronic and robotic systems. Based on the morphological matrix of the …

Pla Polymer Binder In Core Production - Influence On Final Casting Dimensions, Artur Soroczyński, Krzysztof Rechowicz

Virginia Digital Maritime Center (VDMC) Faculty Publications

The foundry industry is seeking an ecological alternative to synthetic molding resins. This study evaluates the technological properties of core sands bonded with biodegradable polylactide (PLA). Cores prepared on a 2% quartz sand matrix were subjected to casting processes using two alloys with extremely different pouring temperatures: gray cast iron (approx. 1200 °C) and AK11 silumin (approx. 710 °C). The research methodology included macroscopic assessment, dimensional analysis using 3D scanning (GOM Inspect), and qualitative knock-out assessment supported by numerical temperature field simulation. The results showed that the high crystallization temperature of cast iron leads to complete thermal degradation of the …

Investigation Of Heavy Metal Composition And Associated Health Risks From Selected Groundwater Wells In Temeke, Dar-Es-Salaam, Justin M. Jeremiah

Tanzania Journal of Engineering and Technology (TJET)

Water quality continues to be the challenge to residents in Dar es Salaam due to various anthropogenic activities in the city. This study was conducted to assess groundwater quality by determining concentrations of heavy metals. Both probability and Nonprobability sampling techniques were used to collect samples from 40 groundwater wells in 24 wards of Temeke municipal and analysed using Microwave Plasma Atomic Emission Spectrometer (Agilent 4210 MP-AES) at the Geochemistry Laboratory of the University of Dar es Salaam. Results indicated varying heavy metal concentrations ranging from 0.71 ± 0.08 to 6.64 ± 0.21 mg/l for As, 0.02 ± 0.01 to …

Inspection Planning Of Subsea Pipeline Using Risk-Based Inspection, Ni Luh Triska Adelia, Badrul Munir, Johny Wahyuadi Soedarsono

Journal of Materials Exploration and Findings

Pipelines are an important tool in oil and gas exploration. Pipeline is a transmission and liquid collection lines, including their accessories, which transport fluids from one plant to another. In transmission and collection process, there is a possibility of failure which can have minor to major impact on personnel injury, the environment and interrupt the business process. To maintain safety and to prevent accidents, the source and cause of failure needs to be calculated. Risk-based inspection (RBI) is a method that can be used to calculate the risk and determine the inspection planning both schedule and method, by combining the …

Optimizing The Expression Of Polyethylene Terephtalate Hydrolase-Encoding Synthetic Gene In Escherichia Coli Arctic Express (De3), Jocelyn Nataniel, Maria Ulfah, Dini Achnafani, Niknik Nurhayati, Gabriela Christy Sabbathini, Sri Rezeki Wulandari, Abinawanto Abinawanto, Is Helianti

Makara Journal of Science

The waste of polyethylene terephthalate (PET) plastic waste in Indonesia is a pressing concern due to its slow degradation and potential environmental damage. One promising solution is to utilize polyethylene terephthalate hydrolase from Ideonella sakaiensis (IsPETase), an enzyme that specifically degrades PET. However, inducing the expression of IsPETase synthetic gene in Escherichia coli BL21 (DE3) has been challenging because much of it remains insoluble. This study aimed to express IsPETase in E. coli Arctic Express (DE3) and optimize the conditions to enhance its production. First, pET22b(+)pelB-IsPETase was inserted into E. coli Arctic Express (DE3). The …

Production Of Biofertilizer From Fruit And Garden Waste, Neema Msuya

Tanzania Journal of Engineering and Technology (TJET)

The project focused on the production of bio-fertilizer from fruit and garden waste, with a specific emphasis on utilizing pineapple tops in the composting process. The objective was to produce and assess the properties of the bio fertilizer obtained from this process and evaluate its potential application in agriculture. In this study, the composting process was done in a 0.7 m long, 0.85 wide and 1.1 m high vessel, and 0.238 m3 pineapple top wastes, resulting in 0.35 m3 of biofertilizer. The bio fertilizer produced exhibited favorable characteristics, including a moisture content of 36%, pH of 7.1, and a total …

Assessment Of Risk Factors Related To Body Pain Complaints In Tanzania Construction Industry, Fatma K. Mohamed

Tanzania Journal of Engineering and Technology (TJET)

The construction industry is associated with risks that can result in musculoskeletal diseases. Although young male workers who are presumed to be healthy dominate the industry in Tanzania, body pain complaints have been widely reported. The aim of this study is to assess the prevalence and causes of body pains in workers. A cross-sectional study involving 396 workers was conducted. A chi square test was used for testing association of independent categorical variables and binary logistic regression analysis was used to determine predictors for body pain complaints. The results show that all study participants complained of at least one form …

Modernization Of Water Flow Measurement In Open Irrigation Systems Using The Slope-Area Method, R.M. Aliev, Djalilov Anvar

Chemical Technology, Control and Management

This article describes two methods for determining water flow in open irrigation systems: “speed - area” and “slope - area”. The authors considered the problem of its modernization using the existing method for determining water flow “slope - area” in open irrigation systems. The essence of the issue is the remote transfer of parameters necessary for calculating water flow in open irrigation systems and improving the means of their processing. In scientific studies conducted by the authors, the required hydraulic parameters were studied using the “slope - area” and “speed - area” water flow methods. Based on experimentally obtained data, …

Evaluation Of Environmental Management System For Small And Medium Enterprises In Dar Es Salaam, Tanzania, Juma M. Matindana

Tanzania Journal of Engineering and Technology (TJET)

A system that manages environmental issues of Small and Medium Enterprises (SMEs) from the time of acquisition of raw materials up to disposal of the product is not well clear, especially in Tanzania. Most of the studies have been conducted in the field of environment management but few of them address the evaluation of the management of SMEs activities with respect to the environment. Although the nature of activities of SMEs has little noticeable environmental implications at the individual level but the impact is large due to diversification and labour intensity of these SMEs. SMEs employ about 20% of the …

A Two-Stage Based Life Cycle And Principal Component Analysis For Decision Support Of Potential Municipal Solid Wastes Management Scenarios, Case Study Dar Es Salaam, Tanzania, Edwin Richard Ndibalema Dr

Tanzania Journal of Engineering and Technology (TJET)

In most of the urban areas of Tanzania, poor and inadequate solid waste management is a growing environmental and public health concern. Despite an array of solid waste management options, choosing an appropriate one remains a challenge. This study applied a novel two-stage-based approach to assess the environmental impacts and sustainability performance of the 27 scenarios for municipal solid wastes (MSW) management of Dar es Salaam City, Tanzania. In the first stage, the study utilized a life cycle analysis (LCA) to quantify the environmental impacts of MSW scenarios. In the second stage, the study used the principal component analysis (PCA) …

Augmented Finite Control Set Mpc Design Technique For Wide Speed Range Control Of Permanent Magnet Synchronous Motor Drives, Francis Mwasilu

Tanzania Journal of Engineering and Technology (TJET)

The effective motion control task is highly influencing the final drive performance in wide-range motor drives applications such as electric vehicles (EVs), washing machines, compressors, elevators and lathe machines. Recently, permanent magnet synchronous motor (PMSM) drive has been widely employed in these applications to achieve desired performances such as high efficiency, high torque requirements with minimum size “occupancy”. The PMSM drive features combining with these modern drive applications are highly nonlinear and the desired operation requirements demand high-performance control schemes with fast system response and robustness features. Linear control schemes are usually implemented to drive the PMSM that entail trade …

Cost Estimation Proxy Models For Economic Evaluations In Petroleum Projects: A Case Study From The Onshore Gas Field In The Southern Coastal Tanzania Basin, Fulmence Kaborogo

Tanzania Journal of Engineering and Technology (TJET)

Petroleum economic evaluation involves estimating revenues from forecasted production profiles and field costs including capital expenditures (CAPEX), drilling expenses (DRILLEX), and operating expenses (OPEX). The existing cost-estimating tool requires several inputs making it time-intensive and difficult to use with few data during the early stages of projects. Majority of the previously developed time saving cost estimations proxy models rely on unrealistic assumptions that include uniform operational costs for different fields with a different number of wells, casings, and drilled depths. This work focused at developing proxy models that consider the variability of the development costs with different parameters. The developed …

Modeling Of Amine-Based Co2 Capture Process, Zafar Safarovich Turakulov

Chemical Technology, Control and Management

A significant factor influencing climate change is the release of carbon dioxide (CO₂) into the atmosphere as a consequence of human activities such as the combustion of fossil fuels. Climate change can be slowed down by taking action to mitigate industrial-scale CO₂ emissions. Currently, the most advanced technology for capturing CO₂ from industrial flue gases is the post-combustion CO₂ capture based on amine absorption. However, due to the high energy penalties of existing CO₂ capture technologies and insufficient carbon markets, it is necessary to develop methods that compete with these technologies or minimize their …