Mechanical Engineering Commons^™

Occupational Safety In Fishing Vessels : A Comparative Analysis Of Namibia, South Africa And Mozambique In The Sadc Region, Fiina Ndakulilwa Twiihaleni Shaanika

World Maritime University Dissertations

No abstract provided.

Assessing Marpol Annex V Port Reception Facilities Of The National Port Of Liberia (Freeport Of Monrovia), Barbara Wade Cummings

World Maritime University Dissertations

No abstract provided.

Experimental Investigation: Performance Of Ranque–Hilsch Vortex Tubes Under Various Surface Boundary Conditions, Ahmad Al-Najjar

Theses

The Ranque–Hilsch vortex tube (RHVT) is a passive thermofluid device that splits compressed gas into simultaneous cold and hot streams through strong swirling flow inside a slender tube, without moving parts. This study experimentally examines how external boundary conditions applied to the tube wall influence RHVT performance. Three wall conditions were imposed: (i) externally cooled (cooling), (ii) externally heated (heating), and (iii) adiabatic (insulated). Tests were conducted with air over an inlet pressure range of 2–6 bar. The primary objective was to understand the extent to which wall thermal condition modifies temperature separation and energy efficiency. Performance was quantified using …

Microstructural And Mechanical Characterization Of Aa6082 /Sic/Al2o3 Hybrid Nano Composite Fabricated By Ultrasonic Assisted Stir Casting, Anasmon Koderi Valappil

Theses

The utilization of aluminium alloys has increased rapidly in past decades due to the increasing demand for lightweight and high-performance materials. Among the popular aluminium alloys, AA6082 is widely favoured for its excellent combination of strength, corrosion resistance, and machinability. Most previous work, however, has concentrated on either on micro scale reinforcement or on single ceramic particles, leaving very few experimental studies on the use of hybrid nano reinforcement in AA6082. Therefore, to further enhance its mechanical properties without compromising its inherent advantages, hybrid metal matrix composites were developed using various nano particulates as reinforcements. In this current study, AA6082-based …

Investigation Of Mechanical Performance And Metallurgical Characteristics Of Titanium Grade 2 Tube-To-Tubesheet Joints, Ahmad Hussein Al Tamimi

Theses

Tube-to-tubesheet joints, an integral component of shell and tube heat exchangers, are known for their vulnerability to leakage problems at the joint region due to mechanical and chemical factors coupled with fabrication techniques involved in creating these joints. An ideal condition of manufacturing process parameters and geometrical variables required to produce tube-to-tubesheet joints is highly desired. One of the most promising candidate materials to fabricate tube-to-tubesheet joints is titanium or titanium alloys due to their excellent strength and resistance to corrosion. The present study investigates the structural integrity of three categories of Titanium Grade 2 based tube-to-tubesheet joints comprising of …

A Gas-Tight Bonding/Sealing Of Different Bulk Ceramics For Robust Oxygen Separation At Ultra-High Temperatures, Guoan Wang, Xingjian Xue

Faculty Publications

Oxygen transport membrane (OTM) is an economic technology for oxygen separation and high-purity oxygen production. To mitigate various issues induced by high temperatures, intermediate temperature OTM technology has been pursued in recent years. However, in certain circumstances, high operating temperatures are unavoidable, such as in situ oxygen production using OTMs for direct oxy-combustion. Nevertheless, the lack of reliable high temperature gas-tight sealing imposes great challenges on OTM technology for such applications. Herein, a novel sealing strategy is developed to obtain a gas-tight bonding/sealing of two different bulk ceramics using ceramic slurry in combination with phase inversion process. The sealing strategy …

Jet Impingement And Vortex/Swirl Cooling Of Different Inlet And Outlet Geometrical Configurations For Turbine Blade Leading Edge Cooling, Irfan Ahmad Sheikh

Thesis/ Dissertation Defenses

Gas turbine blades operate in extreme environments, exposed directly to high-temperature combustion gases that cause severe thermal stresses, weaken material integrity, and may lead to structural failure. Proper cooling is crucial to lower blade temperatures, reduce thermal stresses, prevent failure, and improve overall engine efficiency. This work presents a detailed numerical study of various cooling configurations by applying two advanced leading-edge cooling methods, jet impingement and swirl cooling, across different inlet mass flow rates and jet Reynolds numbers (Rej) ranging from 1,000 to 20,000 to evaluate their cooling performance.

Several advanced leading-edge cooling configurations are proposed and …

Hybrid Multi-Layer Sandwich Beams Using 3d Printing Technology With Energy Absorption Features, Hour Ali Alhefeiti

Thesis/ Dissertation Defenses

This study explores the use of additive manufacturing (AM) technology to create sandwich composite structures, focusing on the manufacturing process, testing, and anticipated impact. The rising cost of manufacturing prototypes using conventional methods has led to the exploration of 3D printing as a viable alternative. The research problem addresses the challenges in manufacturing sandwich composites and the need for automation across the civil, mechanical, aerospace, and aviation industries. The study aims to investigate 3D-printed sandwich composite structures and compare experimental, finite-element analysis, and theoretical results. The proposed methodology includes preparing a CAD model with five different core infill patterns (Cross …

Process-Driven Manufacturability Constraints In Design For Wire Arc Additive Manufacturing, Monsuru Ramoni, Sampson Gholston, Albert E. Patterson

Manufacturing & Industrial Engineering Faculty Publications

Wire arc additive manufacturing (WAAM) has emerged as a useful option for large-scale metal additive manufacturing. It has gained widespread use in the aerospace industry and other applications that require large and complex custom parts. The process is a combination of a precise control system and a welding process, typically GTAW or MIG welding. It is a member of the directed energy deposition (DED) family of AM processes. Compared with many metal AM processes, it is relatively simple and cost-effective but almost always requires a significant amount of postprocessing before parts can be used. The AM-based nature of the process …

Online Cyber-Physical Neural Network Model For Real-Time Hybrid Simulation, Faisal Nissar Malik, Liang Cao, James Ricles, Austin Downey

Faculty Publications

Real-time hybrid simulation (RTHS) is an experimental testing methodology that divides a structural system into an analyticaland an experimental substructure. The analytical substructure is modeled numerically, and the experimental substructure ismodeled physically in the laboratory. The two substructures are kinematically linked together at their interface degrees of freedom,and the coupled equations of motion are solved in real-time to obtain the response of the complete system. A key challenge inapplying RTHS to large or complex structures is the limited availability of physical devices, which makes it difficult to representall required experimental components simultaneously. The present study addresses this challenge by introducing …

Melamine-Based Polymer Nanofibers For Supercapacitors, Samar A. Salim, Hani Nasser Abdelhamid

Nanotechnology Research Centre

This investigation describes the synthesis, electrospinning, and characterization of melamine-glutaraldehyde (MAGA) polymer composites with polymethyl methacrylate (PMMA) for supercapacitors applications. Electrospun fibers are generated by combining the MAGA polymer with PMMA at varying concentrations (2.5 %, 5 %, and 10 wt%). The synthesis of the polymer, its morphological attributes, and structural features are validated by characterization methods e.g., XRD, TEM, SEM, and FT-IR. In a three-electrode configuration, the electrochemical performances of the prepared electrodes are assessed using cyclic voltammetry (CV), galvanostatic charge-discharge (GCDC), and linear sweep voltammetry (LSV). The results suggest that the 5 % MAGA-PMMA composite has a specific …

A New Low-Rate Stable Hydrogel Cathode For Aqueous Zn-Ion Batteries, Roya Rajabi, Shichen Sun, Jamil A. Khan, Morgan Stefik, Kevin Huang

Faculty Publications

Aqueous Zn-ion batteries (ZIBs) are attractive candidates for large-scale energy storage owing to the abundance, low cost, and intrinsic safety of Zn metal. However, their practical application is hindered by poor cycle stability, especially at low current densities, due to cathode dissolution and limited electrochemically active sites (EAS). Herein, a hydrogel-based cathode comprising ammonium vanadate, carbon black, and a Zn-ion-conducting carboxymethyl chitosan–acrylamide hydrogel matrix doped with Zn(ClO4)2 is reported. This design establishes a continuous Zn-ion-conducting network, thereby maximizing EAS density throughout the electrode volume. The ZIB with the hydrogel cathode exhibits outstanding cycling stability, with 77% capacity retention after 2000 …

Graphene Screen-Printed Electrode For Wound-Related Biosensing, Chanyapat Sriviroch

USF Tampa Graduate Theses and Dissertations

Monitoring wound healing is critical for improving patient outcomes, especially for chronic wounds, which often have complications like delayed healing and infections. Current methods for monitoring wound healing are invasive and costly. Also, these methods have a limited ability to provide real-time, continuous data. This study seeks to explore a graphene screen-printed electrode (SPE) electrochemical biosensor that is non-invasive and efficient to constantly monitor wound healing in real time. This research study focuses specifically on the electrochemical detection of the Human Neutrophil Elastase (HNE) and Secretory Leukocyte Protease Inhibitor (SLPI), which is one of the most abundant neutral proteinases in …

Al-Driven Interfacial Gap Prediction In Overlapped Al/Cu Laser Weld Joint For Battery Applications, Hyeonhee Kim, Sanghoon Kang, Cheolhee Kim, Yong Hoon Jang, Minjung Kang

Mechanical and Materials Engineering Faculty Publications and Presentations

The battery tab-to-busbar welding process forms the primary electrical path in battery packs and is directly linked to both performance and safety. Variations in jig alignment, material tolerance, and forming quality can cause small interfacial gaps that lead to weak welds. An artificial intelligence (AI)-driven method was proposed in this study for predicting interfacial gaps in aluminum-copper overlap joints by integrating deep learning with multi-sensor data. A charge-coupled device (CCD) camera, spectrometer, and optical coherence tomography (OCT) sensors were employed to develop and validate deep learning models under varying gap conditions. The results revealed that the variation in melt-pool dimensions, …

Characterizing Surface Waviness Of Aluminum Alloy: An Approach To Minimize Post-Processing In Wire Arc Additive Manufacturing (Waam) Production, Shammas Mahmood Shafi, Anis Fatima, Nicholas V. Hendrickson

Michigan Tech Publications

Wire Arc Additive Manufacturing (WAAM) offers high deposition rates and cost-effective production of large metal components but suffers from poor surface quality, particularly surface waviness, which increases post-processing requirements and limits industrial adoption. Since waviness directly impacts structural integrity, resource efficiency, and industrial applicability, understanding how process parameters govern this feature is critical for reducing post-processing requirement. This study systematically investigated the influence of voltage, travel speed, and wire feed speed on surface waviness in aluminum alloy walls fabricated by WAAM. A two-level factorial design with 16 experiments was conducted, and surface waviness was quantified using height gauge measurements relative …

Experimental Investigation Of 3d Printed Tpu Triboelectric Composites For Biomechanical Energy Conversion In Knee Implants, Osama Abdalla, Milad Azami, Amir Ameli, Emre Salman, Milutin Stanacevic, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Although total knee replacements have an insignificant impact on patients’ mobility and quality of life, real-time performance monitoring remains a challenge. Monitoring the load over time can improve surgery outcomes and early detection of mechanical imbalances. Triboelectric nanogenerators (TENGs) present a promising approach as a self-powered sensor for load monitoring in TKR. A TENG was fabricated with dielectric layers consisting of Kapton tape and 3D-printed thermoplastic polyurethane (TPU) matrix incorporating CNT and BTO fillers, separated by an air gap and sandwiched between two copper electrodes. The sensor performance was optimized by varying the concentrations of BTO and CNT to study …

Development And Justification Of The Structurally-Free Rod Design For Composite Spindles Of Vertical-Spindle Cotton Picking Machines, Nortoji Baratovich Baratov

Technical science and innovation

At present, the light industry constitutes a significant share of the economies of leading countries around the world. Notably, the cotton industry holds a prominent position within the light industry sector. The cultivation of cotton fiber and the harvesting of mature crops without compromising fiber quality represent complex and delicate processes. In order to carry out these operations rapidly and efficiently, various cotton harvesting machines have been developed based on projects proposed by numerous researchers. Among these, the vertical spindle cotton picker is recognized as one of the earliest machines created for this purpose. Since its invention, the vertical spindle …

Structure And Principle Of Operation Of The Vibrational Pressing And Dehydration Unit For Semi-Soft Cheese, Qobiljon Akmal Ugl Muxiddinov, Shakhnoza Abduvaxitovna Sultanova, Azamat Bakir Ugli Usenov

Technical science and innovation

This paper investigates the structural design and operational principles of a vibrational pressing and dehydration unit developed for semi – soft cheese production. The equipment is engineered to optimize whey expulsion and moisture uniformity in curd blocks by combining mechanical pressure with controlled vibration. The unit comprises a stainless – steel vibrating chamber, drainage plates with micro – perforations, and an adjustable frequency–amplitude control system. Vibrations in the range of 20–60 Hz are applied during pressing, promoting more efficient capillary flow and enhancing the separation of whey from curd particles. The process ensures uniform density and texture across the cheese …

A Comprehensive Assessment And Benchmark Studyof Large Atomistic Foundation Models For Phonons, Md Zaibul Anam, Ogheneyoma Aghoghovbia, Mohammed Al-Fahdi, Lingyu Kong, Victor Fung, Ming Hu

Faculty Publications

The rapid development of universal machine learning potentials (uMLPs) has enabled efficient, accurate predictions of diverse material properties across broad chemical spaces. While their capability for modeling phonon properties is emerging, systematic benchmarking across chemically diverse systems remains limited. We evaluate six recent uMLPs—EquiformerV2, MatterSim, MACE, and CHGNet—on 2429 crystalline materials from the Open Quantum Materials Database. Models were used to compute atomic forces in displaced supercells, derive interatomic force constants (IFCs), and predict phonon properties including lattice thermal conductivity (LTC), compared with density functional theory and experimental data. The EquiformerV2 pretrained model trained on the OMat24 dataset exhibits strong …

Microstructural Evolution And Magnetic Properties Of Spark Plasma Sintered Smco5 And Smco5-Fe Composites, Farhan Ishrak, Michael Lastovich, Fu-Yun Tsai, Charles Perkins Iv, Henri Baldino, Alex Helmer, Sean Rego, Sanoj Karki, Daniel Hedlund, Rajeev Gupta, Tushar Borkar

Mechanical Engineering Faculty Publications

Optimizing SmCo(5-)based nanocomposites for high-temperature magnetic applications requires balancing coercivity and saturation magnetization, properties often compromised by grain coarsening, oxidation, and secondary phase formation during conventional sintering. This study investigates the microstructural evolution and magnetic properties of SmCo5 and SmCo5-Fe composites processed via high-energy ball milling followed by spark plasma sintering at 900 degrees C and 1000 degrees C, a route designed to retain the nanostructure while enabling rapid densification compared to conventional sintering. A suite of characterization techniques, including electron microscopy, X-ray diffraction, magnetometry, Magneto-optical Kerr effect, and magnetic force microscopy, reveals the extent of consolidation, phase composition, and …

Control Of Ferroelectric And Dielectric Properties Of Undoped, Fe, And Nb-Doped Single-Crystalline (001) Oriented Pb (Zr0.5ti0.5) O3 Thin Films, Mahamudu H. Mtebwa

Tanzania Journal of Engineering and Technology (TJET)

While several factors that influence the properties of ferroelectric devices have been extensively studied in bulk ceramics and polycrystalline thin films, limited is known about the same on single crystalline thin films which have great potential in memory and energy applications. This knowledge gap is largely due to the limited availability of substrates with lattice parameters suitable for supporting high-quality epitaxial growth. In this study, undoped, Fe-doped, and Nb-doped (001)-oriented Pb(Zr₀.₅Ti₀.₅)O₃ thin films were deposited using pulsed laser deposition, each with a SrRuO₃ bottom electrode and a PrScO₃ substrate. The doping concentration used is 1% for both Fe and Nb. …

Techno-Economic Analysis Of Hybrid Pv-Wind-Diesel Generator Swarm Grid For Rural Electrification In Tanzania, Ibrahim Mwammenywa

Tanzania Journal of Engineering and Technology (TJET)

Remote, rural, and off-grid communities, particularly in Sub-Saharan Africa (SSA), face significant challenges in securing reliable and affordable electricity. While solutions such as solar home systems (SHSs) and diesel generators (DGs) have been adopted by some individuals, their deployment is often not optimized to meet the full load demand. This study addresses this challenge by proposing a hybrid swarm grid (HSG) design that integrates photovoltaic (PV), wind energy, and diesel generators (DGs). Utilizing MATLAB/Simulink and HOMER, the HSG is modeled and optimized for a typical SSA village, incorporating real-world variables such as load demand profiles, solar irradiance, and wind patterns. …

Adoption Of Agrivoltaics In Developing Countries: A Review On Challenges, Opportunities And Future Prospects, Abdi J. Athumani, Pater Makolo

Tanzania Journal of Engineering and Technology (TJET)

This paper provides a review of agrivoltaics technology and how it has been applicable in developing countries, including African countries. Agrivoltaics, the integration of agricultural production with photovoltaic energy generation, offers promising solutions to water- energy-food nexus in developing countries. This technology offers the dual benefit of increasing agricultural productivity while generating clean energy, which is very important for regions facing frequent electricity shortages and declining agricultural yields due to climate change. However, despite its potential, the adoption of agrivoltaics in developing nations remains limited in comparison to developed countries due to financial, technical and policy constraints. This paper explores …

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 …

Optimal Location And Sizing Of Facts Devices To Improve Voltage Profiles On A 132 Kv Mwanza-Musoma-Nyamongo Transmission Line, Peter Makolo

Tanzania Journal of Engineering and Technology (TJET)

Recently, utility companies have desired to supply quality, stable and reliable power to customers, and ensure they meet the demand. Flexible AC Transmission Systems (FACTS) dynamic compensator devices such as Static Synchronous Compensator (STATCOM), Static VAr Compensator (SVC) and Unified Power Flow Controller (UPFC) are an impeccable choice, however, cost is one of the limiting factors following these technologies. In addition, using FACTS devices in the system requires a detailed steady state, dynamic and optimisation analysis to effectively meet the purpose and ensure reduced cost. This paper proposes using an optimised FACTS device to improve voltage profile, power transfer, system …

Investigating The Harmonic Content Of A Pwm Inverter With Varying Modulation Index, Peter Makolo

Tanzania Journal of Engineering and Technology (TJET)

Photovoltaic energy is a clean and endless vital renewable energy. In order to generate electricity from solar energy an inverter is required to transform the direct current into alternating current. Also, with the emerging of new ultra-high voltage direct current transmission technology, the rectification and inverters play a great role. Most three-phase two-level inverters draw harmonics that cause heat dissipation, waveform distortions hence affect the electrical loads. Knowing that Total Harmonic Distortion content of voltage source inverter is important and must be within the allowable range. Several schemes are suggested to mitigate the distortion in order to produce as much …

Enhancing 6g Network Security With Quantum Key Distribution: A Comprehensive Review, Bassma M. Kamil

Al-Esraa University College Journal for Engineering Sciences

With the considerable progress of sixth-generation (6G) networks further on the horizon, security has attracted much attention in the face of increasingly sophisticated threats, especially from quantum computing. Classical cryptographic schemes based on computational hardness are becoming more and more brittle, as they can easily be attacked with a quantum computer. Quantum Key Distribution (QKD) arises as a promising tool for information-theoretic security through quantum mechanics to obtain an unbreakable key by exchanging unknown bit sequences. In this paper, we provide an extensive survey on the integration of QKD both in the envisioned 6G architecture, including current implementations, technical feasibility, …

Protection The Nfv Net-Work Using The Random Forest Classification, Mustafa H. Taha, Ibtesam Jomaa Hawi, Wafaa Waheeb Abdullah Ali

Al-Esraa University College Journal for Engineering Sciences

A misuse attack is the most common and dangerous type of attack that could target NFV (Network Function Virtualization). In a misuse attack, the attacker attempts to consume the NVF environment’s resources by sending a large amount of traffic. To protect the NFV environment, an early and accurate misuse attack detection system has been proposed based on NFV and Random Forest Classifier. The proposed model starts with importing the dataset and analyzing it then pre-processing and feature selection using a PSO (particle swarm optimization) Test algorithm, classification is based on the most common and efficient machine learning technique, which is …

Design Of A Hybrid System For Powering Wireless Communication Units, Samer Rabih, Ahed Alboody

Al-Esraa University College Journal for Engineering Sciences

Wireless and optical communication units are becoming more widespread nowadays, especially in rural areas. Therefore, feeding electricity has become essential for the continuity of services. As a result of economic and social development, there has been an urgent need to supply electrical power for the basic requirements of wired and wireless telecommunications equipment. This is linked to public safety, long life, and connection to uninterruptible power systems to ensure continuous power supply, whether from renewable energy sources or traditional diesel systems. This research studies and designs a renewable energy (solar) power system to power telecommunications equipment. The proposed power system …

Dynamic Ris-Enabled Massive Mimo Noma Systems Power Allocation Optimization For 6g Using Machin Learning Approach, Mohamed Hassan, Khalid Hamid, Salah Hagahmoodi, Elmuntaser Hassan

Al-Esraa University College Journal for Engineering Sciences

This study examines spectral efficiency (SE) and throughput throughout a spectrum of user densities (from 50 to 1000 users), user mobility speeds (0 to 350 km/h), latency, packet loss, and fairness index, within a wide range of signal-to-noise ratios (SNRs). The analysis includes a number of different situations, such as (i) cooperative non-orthogonal multiple access (NOMA) with massive multiple-input multiple-output (mMIMO), (ii) mMIMO cooperative NOMA integrated with cognitive radio (CR), and (iii) CR-assisted mMIMO cooperative NOMA enhanced with reconfigurable intelligent surfaces (RIS). All of these are part of 6G millimeter-wave (mmWave) networks. The study investigates the enhancement of latency, packet …