Applied Mechanics 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 …

Structural Design And Finite Element Analysis Of A 54 Ton Freight Wagon Bolster Test Rig Under Vertical Center Plate Load, Shandy Dwi Prayoga, I Dewa Gede Ary Subagia, I Ketut Adi Atmika, Abdul Rohman Farid, Yunior Lanang Satrio

Journal of Mechanical Engineering Science and Technology (JMEST)

Bolster is one of the bogie's components that receives direct loading from the car body and freight movement. One of the problems that occurs in the bolster is permanent deflection during vertical and transversal static loading. Therefore, a static loading test is required to evaluate the structural strength of the bolster. During the static loading test, a rig is required to hold the bolster so that the bolster is in a fixed position. The rig owned by PT. INKA (Persero) showed a plastic deformation at the vertical center plate load (VCP 5.22P). Therefore, a modified design of the rig is …

Optimization And Energy Efficiency Analysis Of An Automatic Feed Mixer With A Rotating Drum Mechanism, Kris Witono, Talifatim Machfuroh, Nurlia Pramita Sari, Lisa Agustriyana, Aini Lostari

Journal of Mechanical Engineering Science and Technology (JMEST)

Energy-efficient feed mixer machines are important for improving the productivity and sustainability of small and medium-scale livestock farms. Previous studies primarily focused on either structural performance or mixing efficiency, with limited studies integrating both aspects. Therefore, this study evaluated an automatic rotating-drum feed mixer by combining Finite Element Method (FEM) analysis and energy modeling. The study used FEM simulations for different materials, namely A36 steel alloy, stainless steel 304, aluminium 6061, and galvanized steel, with thicknesses of 3 mm and 4 mm, as well as different drum systems. The FEM results showed that all evaluated materials met the minimum safety …

Analytical Study Of Transient Mixed Convective Radiative Jeffrey Fluid Flow With Diffusion–Thermo And Chemical Reaction, V. Sathiya, R. Vijayaragavan, B. Rushi Kumar

Mansoura Engineering Journal

This research examines the behavior of unsteady mixed convective radiative Jeffrey fluid flow over a permeable moving plate with a diffusion thermo effect. The study incorporates multiple factors, including aligned magnetic fields, heat generation, radiation, and chemical reactions. The behavior of Jeffrey fluid under these combined conditions is particularly relevant to the design of efficient heat exchangers, MHD generators, and cooling systems for electronic components. A regular perturbation technique was employed to solve the governing equations, yielding distributions for velocity, temperature, and species concentration. These solutions enabled the derivation of expressions for skin friction, Nusselt number, and Sherwood number. Through …

Cnn-Based Hybrid Model For Detecting Blight Diseases In Potato Crops With Advanced Image Processing Techniques, Farian S. Ishengoma

Tanzania Journal of Engineering and Technology (TJET)

Potato production plays a vital role in global agriculture as a major food source for large populations. However, potato crops are highly susceptible to diseases, particularly Early Blight and Late Blight, which result in substantial yield losses. Timely detection and effective control of these diseases are essential for maintaining stable crop output. This study explores the integration of Convolutional Neural Networks (CNNs) and advanced image processing techniques to differentiate between diseased and healthy potato plants accurately. Two datasets comprising original and enhanced images were used to train four CNN models: InceptionV3, Xception, Densenet201, and Resnet152V2. The original images underwent background …

Effect Of A Small Control Rod On The Aerodynamic Forces And Wake Structure Of Side-By-Side Cylinders At Moderate Reynolds Number, M. M. Mosallem

Journal of Engineering Research

The unsteady wake interaction between two side-by-side circular cylinders often leads to significant vortex shedding and fluctuating aerodynamic forces. This numerical study investigates the effect of a small passive control rod with a rod-to-cylinder diameter ratio d/D = 0.07 on the wake dynamics and aerodynamic forces of two side-by-side circular cylinders. Two configurations are explored: one where the control rod is placed directly behind the cylinders (x/D = 0), and another where it is located downstream (x/D = 0.5). The two cylinders are arranged with a center-to-center spacing ratio T/D = 1.25. The simulations were …

Design Of A 10-Ton Capacity Solar-Powered Cold Storage At The Cituis Fish Auction Site, Tangerang, Banten, Indonesia, Wardi Wardi, Muhammad Arif Budiyanto

Journal of Materials Exploration and Findings

This study presents the design of a 10-ton capacity solar-powered cold storage system for the Cituis Fish Auction Site (TPI) in Tangerang, Indonesia, as a sustainable solution to support the coastal fisheries sector. The system comprises two temperature zones: an anteroom at 5°C and a freezer room at -30°C, both integrated with a hybrid system utilizing solar panels and batteries. The total power consumption of the cooling system reaches 27.51 kW. The simulation results, obtained using HOMER Pro software, indicate that the hybrid PV system can reduce CO₂ emissions by up to 16,754 kg per year. From an economic …

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 …

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*). …

The Effect Of Hot Machining Of Difficult-To-Machine Materials On The Form Accuracy In The Turning Process, Ahmed Yehia Kamal, Samy F. M. Assal, Ahmed M. El-Kassas, Ahmed A. Hawam

Journal of Engineering Research

Form accuracy of machined parts is crucial to the interchangeability in production as well as the function of the part and its expected useful life. Numerous studies investigated the form accuracy in traditional machining operations but none of them considered this issue in hot machining. In this technique, a difficult-to-machine workpiece is preheated to soften its material and reduce the cutting force. In this paper, the form accuracy represented in roundness, tape, and straightness of hot turned AISI 304L parts are investigated. The results showed that the hot condition has a minimal effect on the form accuracy which confirms the …

Numerical Simulation Of Airflow Properties Of The Naca 6420 Airfoil Using The Transition Rans K-Ε Model, Oluwaseyi O. Alabi, Saidat A. Salisu, Oyeyemi T. Aforolagba -Balogun, Temitope A. Ladigbolu, Ayotunde O. Fasina, Anas Bala

Al-Bahir

This study investigates the airflow properties around the airfoil using numerical simulation, addressing the longstanding challenge of accurately predicting transition phenomena in turbulent flows. The importance of this research lies in its potential to improve the design and performance of airfoils in various engineering applications, such as wind turbines, and aircraft. A custom 2-dimensional airfoil model was created using Airfoil instruments, featuring a 6% maximum curvature, 40% curvature position, and 20% thickness. COMSOL Multiphysics software performed computations at a velocity of over 19 hours, with data analyzed at 60-minute intervals. The Transition turbulent model was employed to simulate the airflow …

Effects Of Thermal Shock Protection Methods On Pressure Measurements In A Rapid Compression Machine, Myeji Materego

Tanzania Journal of Engineering and Technology (TJET)

The study investigates the impact of thermal shock protection methods on pressure measurements in Rapid Compression Machines (RCMs). It focuses on the performance of various pressure transducers, specifically 601A, 701A, 6061B, and 7005, under atmospheric initial conditions. The research emphasizes the importance of mounting techniques and coatings, revealing their significant effects on pressure trace accuracy. Special mounting adaptors for the pressure transducers were designed and manufactured, this enabled simultaneous measurements for all transducers to be made in a single compression stroke. Instantaneous pressure within combustion chamber was measured when air was compressed in RCM from initial pressure and temperatures of …

Development Of A Drive-Rod Unified Variable Pitch Control Mechanism For Small-Scale Horizontal Wind Turbines, Ayman I. Bakry, Mohamed Elfouly, Omar Mehrez

Journal of Engineering Research

Typically, small-scale wind turbines use either a breaking equipment or stall control methods once the wind speed exceeds its rated value. This is to limit the power extracted from the wind turbines which largely depends on the blades' shape and pitch angle. Most of small-scale wind turbines are of fixed pitch angle to avoid complexity and cost. In this work, a novel drive-rod unified variable pitch drive mechanism is proposed for blades pitch control for small-scale horizontal wind turbines. The mechanism is powered by a DC motor coupled with a lead screw which in turn is connected to the pitch …

Pd Controller Design For Automotive Magnetorheological Semi-Active Suspension System, Ayman I. Bakry, Emad M. S. El-Said, Ahmed Shehata Gad, Ahmed Abd Almoez, Omar Mehrez

Journal of Engineering Research

Recently, there is a tendency towards the utilization of magnetorheological (MR) dampers in electrical vehicles (EV) due to its adaptability of active control devices with lower requirement of large power sources compared to the active damping systems. This paper investigates the performance of the most used control technique for MR dampers used in EV, the PID controller, under different road conditions. In this investigation, the Dynamic-Damper-Motor System (ADM-EV) is used as the EV suspension system model. Meanwhile, modified Bouc-Wen model is used as the MR damper model. The design procedure for the optimum design of the system controller parameters is …

Smart Materials For Noise And Vibration Damping In High-Speed Rail Systems: A Comparative Analysis, Hyginus Chidiebere Onyekachi Unegbu, Danjuma Saleh Yawas, Bashar Dan-Asabe, Abdulmumin Akoredeley Alabi

Makara Journal of Technology

Effective noise and vibration control remains a critical challenge in high-speed rail systems, directly influencing passenger comfort and the longevity of infrastructure. This study evaluated four advanced materials—piezoelectric materials, shape memory alloys (SMAs), magnetorheological (MR) fluids, and damping composites—focusing on their potential for mitigating noise and vibration in high-speed rail applications. A combination of experimental and simulation-based analyses was employed to assess these materials based on their noise reduction coefficient, vibration transmissibility ratio, thermal stability, and durability under varying environmental conditions. The findings revealed that damping composites and SMAs demonstrated superior performance, offering enhanced noise attenuation and vibration control compared …

Assessing The Importance Of Air-Decking Blasting In Controlling Bigv At An Open Pit Gold Mine In Tanzania Using Ann Model, Karim R. Baruti

Tanzania Journal of Engineering and Technology (TJET)

Air-decking blasting technique is used to control blast induced ground vibration (BIGV) in several mines including open-pit gold mines located in Tanzania. While the importance of air-deck to control BIGV is practically evident, theoretical models such as BIGV prediction models cannot be used to assess the importance of air-decking. The main objective of this study was to assess the importance of the air-decking blasting technique to control BIGV using the artificial neural network (ANN)Model. To achieve this objective, ANNs were modeled and trained to learn the pattern of data using Multilayer Perception with Back Propagation to predict BIGV. The main …

Assessment Of An Assumed Strain-Based Triangular Membrane Element, Abdelhak Kherfi, Kamel Zouggar, Khelifa Guerraiche, Djemaa Guerraiche, Antar Tahiri

Emirates Journal for Engineering Research

This paper presents a novel triangular strain-based element designed to address plane stress and strain, axisymmetric, and dynamic problems. The proposed element has four nodes, three of which are located at the vertices and one of which is located at the midpoint of the diagonal. The corner nodes have three essential external degrees of freedom (u, v, θ), while the central node has two degrees of freedom (u, v) on one of the triangle edges. A static condensation-based treatment of the central node is employed to streamline the model and reduce computational overhead. This triangular element …

Research In Robotics: Vex Robotics, Dylan Wagner, Darec Wagner, Lyric Yost, Alexander Redinger, Yue Fan, Mark Hamrick, Mufeng Shen, Lawrence Yan

SACAD: Scholarly Activities

Throughout the past year our group has been working toward the construction of a robot. Our goal with this robot was to compete in the competition laid out by VEX robotics. Our robot would be built using the VEX robotics pieces as well as some custom-made parts. We utilized the engineering design process to ensure that we were working as efficiently as possible, whilst also working towards making the greatest bot. The first semester had us split into two teams, with both going to Pittsburgh KS to compete against other universities from across the state. After this competition, we combined …

Effects Of Redrying Methods On The Milling Potential, Crude Protein And Total Phenolic Content, And Antioxidant Activity Of Stored Inorganic And Organically-Grown Paddy, Mary Ann Baradi, Jessica Solero, Clarence Dangcil, Gerome Corpuz, Marissa Romero

The Philippine Agricultural Scientist

This study sought to determine the effects of redrying techniques (no redrying or Control, 2-h, 4-h, and 6-h redrying with stirring every 30 min, Farmer's Practice or 6-h redrying with one stirring) on grain quality of stored inorganic and organic paddy rice as well as the redrying method that gives the best quality rice. PSB Rc82 rice harvested in October 2016 was used in the experiment conducted in February 2017. Quality parameters evaluated were moisture content, brown rice, total milled rice, crude protein content in percent, total phenolic content, and 2-2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. PSB Rc82 paddy exposed …

Enhancing The Performance Of Conventional Solar Still Using The Nano-Doped Paint (Ndp) Coating, Hagar Alm-Eldin Bastawissi Prof.Dr, Nermin Elgendy Engineer, Ayman R. El-Tohamy

Journal of Engineering Research

Nations are throughout the entire globe continuously confronting the problem of potable water shortage. Recently, it has been thought that using solar energy to desalinate brackish water offers a practical answer to the world's water crises. The output of these stills, is meager, and academics haven't done much to boost it in any way. Solar distillers have been proposed as an efficient method to produce potable water. In recent years, saltwater has produced drinking water by various ways. The efficiency of a solar distiller is significantly influenced by various factors, most important factor of them is the absorber surface. In …

Impact Of Glottis Area On Airflow Dynamics In The Human Trachea Using A Simplified Stenosis Pipe Model, Amany M. Kamal, Momtaz Sedrak, Abouelmagd Abdelsamie

Trends in advanced sciences and technology

A complex transitional flow is produced in the larynx during air inhalation process, pivotal for fundamental comprehension and medical advancements in treatment methodologies. This study delves into the influence of the glottis region utilizing a simplified stenosis pipe geometry, examining two distinct cases: (1) the axisymmetric case and (2) the eccentric case. Reynolds-averaged Navier–Stokes equations with shear stress transport (SST) 𝑘 − 𝜔 turbulence model with intermittency transition activated with steady, Newtonian, and incompressible airflow have been used. The analysis underscores the significant impact of the eccentricity on the velocity by increasing 0.6% comparing with axisymmetric case, also particularly affecting …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Extraction And Characterization Of Fibres From The Bark Of Ficus Nekbudu Tree, Liberato V Haule

Tanzania Journal of Engineering and Technology (TJET)

This paper investigates the extraction and characterization of fibres from the bark of the ficus nekbudu tree. The Ficus Nekbudu Fibres (FNF) was extracted from the bark by retting in water and then treatment with sodium hydroxide solution. The extracted FNF was analysed for chemical composition, physical, tensile, surface, structural and thermal stability properties. Findings on the chemical composition indicated that FNF has cellulose (49.9 %), lignin (13.4%), ash (7.1%) and water content (8.1%). From the physical investigation it was found that FNF has density (1.42 ± 0.005 g/cm3) and moisture regain (9.2 ±0.3%). From mechanical investigation it was found …

Designing A Cylindrical Capacitive Based Sensor For Monitoring The Table Salt’S Moisture Content During Iodization, Mwajuma Lungo

Tanzania Journal of Engineering and Technology (TJET)

Coaxial cylinder capacitive moisture sensor for determination of moisture content of table salts has been fabricated. The CMS method for determination of moisture content of table salts overcomes the effect of evaporation of iodine in table salt which results from heating in the oven drying method. The CMS overcomes the polarization effect result from the resistive methods of moisture content determination and it is non expensive to construct and it has high accuracy since measurements involves programming system in interpretation of the results. In this research, moisture content sensor based on capacitive principal created using two coaxial cylinders with height …

Application Of Mangrove Timber In Reinforcing Concrete, John K. Makunza Jkm

Tanzania Journal of Engineering and Technology (TJET)

Use of mangrove timber beams for supporting floor slabs in historic buildings in Zanzibar Stone Town is still applied although the available structural data on mangrove timber is inadequate. This concern has called for an investigation on the structural properties of mangrove timber, so that the information obtained could help to establish the structural strength of the existing floor slabs in historic buildings. Hence, mangrove timber specimens were sampled from Zanzibar, and tested in the laboratory for their strengths in tension, compression and shear. The test results showed that mangrove is a hardwood timber of strength class D70, the highest …

Experimental Investigation On Recovery Of Micro Hydropower Dump Load Through Oil Heating System, Joseph H. Kihedu Dr.

Tanzania Journal of Engineering and Technology (TJET)

Micro hydropower power generates electrical energy to meet connected electrical demand, that normally fluctuates causing imbalances. Electronic load controller is then used to balance power system by diverting surplus generated power to the dump load commonly resistive load such as bulk water heater. This study investigated use of oil heating system as a replacement for conventional resistive dump load. In comparison to water, oil has high thermal retention therefore can serve as good thermal media. Dump load range ranged between 17 kW to 78 kW. A 6-kW electrical heater was used for laboratory oil heating system from which heated oil …

A Perspective Into Development Of Pavement Design Methods For Low Volume Roads: A Review, Mwajuma Lingwanda

Tanzania Journal of Engineering and Technology (TJET)

The definition of low volume roads (LVRs) is not time static and it varies from place to place around the world. The importance of such roads for providing access, in connecting communities and link farms to markets is well appreciated worldwide. LVRs are credited as the direct source of social economic development in rural communities, growth, reduction of poverty and sustaining livelihood. Nevertheless, the LVR network is growing at an unsatisfactory rate especially in Sub-Saharan Africa. The slow rate in developing LVR network is attributed to the high cost of construction and maintenance. To the author’s perspective, research has a …

Review On Modifications Of Sisal Fibers For Textile Applications, Liberato V Haule

Tanzania Journal of Engineering and Technology (TJET)

Properties of sisal fibers such as high coarseness and poor drapability made the fibers less suitable in production of conventional textiles compared to synthetic fibers. The environmental consciousness and depletion of petrochemical resources have attracted researchers on investigating the use of natural fibers in the industrial production of conventional textiles. Sisal is among highly researched natural fibers due to its features such as strength, recyclability, availability, low processing cost, light weight and ease process ability. This paper reviews possible modifications of sisal fibers to enhance performance in conventional textiles applications

Sensible Heat Bean Cooker, Casiana Lwiwa

Tanzania Journal of Engineering and Technology (TJET)

Alternative cooking energy to replace wood fuels is needed in the African context. Liquified Natural Gas (LNG) is a solution but is still based on burning fossil fuel. Electrical cookers can be an alternative as well. However, for off-grid systems this means electrical batteries are required, as the solar electricity from Photovoltaic (PV) panels is intermittent, and as cooking is also to be made after sunset. Heat storage technologies can provide solutions where available energy is stored in the form of heat for cooking when needed. The challenge is then to develop systems which are robust, safe, and technically simple. …

Preparation And Characterization Of Microporous Cellulose Membranes As Potential Pathogen Filters, Peresi M. Bulemo

Tanzania Journal of Engineering and Technology (TJET)

Growth and development in the textile and fashion industry have resulted in the generation of large amounts of industrial pre consumer textile wastes. It is estimated that 10 to 20% of textile fabrics are wasted during garment manufacturing, with most of the wastes being burned or landfilled. Reusing pre-consumer fabric wastes is therefore considered a viable approach to alleviate environmental impacts associated with their disposal. To achieve a higher porosity membrane, pre-consumer cotton fabrics were partially dissolved in a solution of dimethyl acetamide (DMAc) and lithium chloride (LiCl), and the resulting fibre suspension was utilized to prepare a microporous cellulose …