Mechanical Engineering Commons^™

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 …

Comparison Of Meteorological Drought Indices In Tanzania Using The Meteorological Drought Monitoring Software Package, Paul Ts Limbu

Tanzania Journal of Engineering and Technology (TJET)

Low precipitation, substantial evaporation, and an unequal distribution of precipitation throughout the area are the characteristics of drought, a climatic abnormality. This study used the Meteorological Drought Monitoring (MDM) software and monthly rainfall data from the Tanzania Meteorological Authority (TMA) to examine and compare the Deciles Index (DI), Standardised Precipitation Index (SPI), Percent of Normal Index (PNI), Rainfall Anomaly Index (RAI), Z-Score Index (ZSI), China-Z Index (CZI), and Modified China-Z Index (MCZI) for drought monitoring in Tanzania from 1988 to 2017. It was found that ZSI represented the dry years better than other indices, followed by DI, RAI, PNI, SPI, …

An Optimization Tool For A Standalone Photovoltaic System, Johanes Kasilima

Tanzania Journal of Engineering and Technology (TJET)

Stand-alone photovoltaic systems (SAPV) are often used in remote areas where access to grid electricity is limited. This system depends on solar energy. However, Photovoltaic (PV) systems need a greater initial investment than conventional sources of energy, and their effectiveness is reliant on a number of environmental conditions such as the unpredictable solar radiation. One step in reducing the investment cost of a PV system is determining the optimal size of solar PV components that minimize costs. This paper presents a Particle Swarm based optimization tool for sizing Stand-alone PV systems. The optimization tool selects the optimal Levelized Cost of …

Electron-Phonon Interaction Mediated Gigantic Enhancement Of Thermoelectric Power Factor Induced By Topological Phase Transition., Zhi Li, Koushik Pal, Huiju Lee, Chris Wolverton, Yi Xia

Mechanical and Materials Engineering Faculty Publications and Presentations

We propose an effective strategy to significantly enhance the thermoelectric power factor (PF) of a series of 2D semimetals and semiconductors by driving them toward a topological phase transition (TPT). Employing first-principles calculations with an explicit consideration of electron-phonon interactions, we analyze the electronic transport properties of germanene across the TPT by applying hydrogenation and biaxial strain. We reveal that the nontrivial semimetal phase, hydrogenated germanene with 8% biaxial strain, achieves a considerable 4-fold PF enhancement, attributed to the highly asymmetric electronic structure and semimetallic nature of the nontrivial phase. We extend the strategy to another two representative 2D materials …

Guidelines For Data Collection On Energy Performance Of Higher-Education Buildings In Egypt: A Case Study, Hesham Safwat, Ahmed A. Abdel-Rehim, Iman El-Mahallawi, Abdelwahab Hussein, Engy Elshazly, Ahmad Elshamy

Mechanical Engineering

Reliable energy analysis of buildings relies heavily on high-quality data leading to proper indicators. Previous studies have highlighted the importance of data quality in analyzing energy usage in residential and non-residential buildings in order to transform declarations to actions, optimise energy efficiency policies and monitor progress and failures in countries. Collected data must adhere to national and international standards for energy performance in buildings. This study aims to provide practical guidelines for effectively collecting and preparing data suitable for evaluating energy performance in Egyptian higher-education (HE) buildings. The guidelines are developed based on a comprehensive case study, considering data availability …

Integrated Analysis Of Economic Optimization And Life Cycle Assessment For A Fully Modular Wheelchair Accessibility Ramp Utilizing Recyclable Materials, Nicolas Whelan

Honors Scholar Theses

In response to the growing emphasis on sustainability and accessibility in infrastructure development, this research paper delves into the optimization of economic opportunities presented by fully modular wheelchair accessibility ramps. By integrating principles of modularity, recyclability, and circular design, these ramps offer a promising solution to the dual challenges of accessibility and environmental impact. The study employs interdisciplinary methods, merging design, economics, and environmental sustainability, to evaluate the feasibility and potential of these innovative ramp designs. Central to the analysis is the application of a Life Cycle Assessment (LCA) to quantify the environmental impact and carbon footprint associated with modular …

Analyzing The Effects Of Atmospheric Turbulent Fluctuations On The Wake Structure Of Wind Turbines And Their Blade Vibrational Dynamics, Alayna Farrell, Fernando Ponta, Apurva Baruah

Michigan Tech Publications

In recent trends, a rising demand for renewable energy has driven wind turbines to larger proportions, where lighter blade designs are often adopted to reduce the costs associated with logistics and production. This causes modern utility-scale wind turbine blades to be inherently more flexible, and their amplified aeroelastic sensitivity results in complex multi-physics reactions to variant atmospheric conditions, including dynamic patterns of aerodynamic loading at the rotor and vortex structure evolutions within the wake. In this paper, we analyze the influence of inflow variance for wind turbines with large, flexible rotors through simulations of the National Rotor Testbed (NRT) turbine, …

Measuring Soot In A Novel Configuration For Diffusion Flames Fueled By Ethylene Doped With Iso-Dodecane, Christian Bjork

Honors Scholar Theses

Sustainable Aviation Fuels (SAFs) are seen as the path forward for decarbonizing hard-to-electrify sectors. Using SAFs over traditional fossil fuels abates carbon dioxide emissions but still may present soot emission problems. A milestone in the abatement of soot would be understating its formation mechanisms.

This study aims to quantify soot products resulting from an ethylene flame doped with iso-dodecane, a surrogate SAF component. The burner selected for the investigation is the novel Planar Mixing Layer Flame (PMLF) which allows the tracking of soot formation with the height above the burner (HAB) in a stable diffusion flame. A baseline ethylene-fueled flame …

Thermal Performance Investigation Of Thermoelectric Cooling System With Various Hot-Side Cooling Methods, Bowo Y. Prasetyo, Parisya P. Rosulindo, Fujen Wang

Makara Journal of Technology

Thermoelectric devices have been widely used in various applications, including cooling and power generation. The potential application of thermoelectric cooling systems has been studied. However, these systems still face challenges in achieving optimal performance compared with other cooling systems. Several factors, including the hot-side cooling method, influence the performance of thermoelectric systems. This study aimed to investigate the effects of different hot-side cooling methods on the thermoelectric performance and thermal behavior of thermoelectric cooling systems. The testing methods involved the combination of the thermoelectric module with five hot-side heat exchangers, including a square heatsink, a round heatsink, a two-pipe heat …

Reducing Glass Loss During Transportation And Storage, Abdulaziz Muzafarovich Qurbanov, Mirzaabdullayev Jaxongir Baxtiyorovich

Technical science and innovation

The article discusses the processes of transportation and storage of sheet glass in the production of protective glass for cars. The experience of organizing the transportation and storage of glass in developed countries of the world was analyzed in order to study the problems of losses of raw materials during the transportation and storage of laminated glass, as well as to develop and approve a regulatory and technical document. in this field. The supplies of various brands of polished laminated glass used in the production of protective glass for cars to Avtooina LLC from different addresses, from different manufacturers were …

Aerodynamic Design And Analysis Of A Modified 2006 Mazda Miata, William N. Recher

Honors College Theses

Aerodynamic forces developed by automobiles have destabilizing effects at high speed. These forces tend to skew toward a vehicle’s rear which can present safety concerns, especially for rear-wheel-drive automobiles like the Mazda Miata. To address oversteer and high-speed instability, a vehicle’s design can be tailored to bring about aerodynamic balance and improve traction. LiDAR was used to bring the physical automobile into the digital space. Then, a splitter and diffuser were added to reduce the magnitude of the destabilizing forces. Next, the size and shape of the rear-wing required to balance the vehicle was calculated using a combination of parameters …

Experimental Investigation Of Various Hydrogen Knock Limit Extension Strategies On A Hydrogen-Gasoline Dual Fuel Spark Ignition Engine, Sanad Puthan Purayil

Thesis/ Dissertation Defenses

Hydrogen is a clean and carbon free substitute with the ability to significantly cut down the harmful emissions while enhancing the energy efficiency of internal combustion engines (ICE) typically powered by conventional fossil fuels. Hydrogen is the most abundant element which can be easily obtained from sources like water and biomass. The wide flammability range and high laminar flame velocity outstands hydrogen from other fuels. However, hydrogen fueled engines are more prone to abnormal combustion like knock and backfire due to its low ignition energy and high adiabatic flame temperature. To avoid backfire, several well-developed approaches have been reported. Unlike …

Optimal Molecular Dynamics System Size For Increased Precision And Efficiency For Epoxy Materials, Khatereh Kashmari, Sagar Patil, Josh Kemppainen, Shankara Gowtham, Gregory Odegard

Michigan Tech Publications

Molecular dynamics (MD) simulation is an important tool for predicting thermo-mechanical properties of polymer resins at the nanometer length scale, which is particularly important for efficient computationally driven design of advanced composite materials and structures. Because of the statistical nature of modeling amorphous materials on the nanometer length scale, multiple MD models (replicates) are typically built and simulated for statistical sampling of predicted properties. Larger replicates generally provide higher precision in the predictions but result in higher simulation times. Unfortunately, there is insufficient information in the literature to establish guidelines between MD model size and the resulting precision in predicted …

Injectable And Rapidly Expandable Thrombin-Decorated Cryogels Achieve Rapid Hemostasis And High Survival Rates In A Swine Model Of Lethal Junctional Hemorrhage, Syed Muntazir Andrabi, S.M. Shatil Shahriar, Al-Murtadha Al-Gahmi, Benjamin L. Wilczewski, Mark A. Carlson, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Effective therapies are urgently needed to stabilize patients with marginally compressible junctional hemorrhage long enough to get them to the hospital alive. Herein, we report injectable and rapidly expandable cryogels consisting of polyacrylamide and thrombin (AT cryogels) created by cryo-polymerization for the efficient management of lethal junctional hemorrhage in swine. The produced cryogels have small pore sizes and highly interconnected porous architecture with robust mechanical strength. The cryogels exhibit rapid shape memory properties and prove to be resilient against fatigue. These cryogels also show high water/blood absorption capacity, fast blood clotting effect, and enhanced adhesion of red blood cells and …

10-Year Progress Assessment Of Made In China Strategy—Perspective Based On U.S. Publications, Wen Wang, Yujing Shen

Bulletin of Chinese Academy of Sciences (Chinese Version)

Manufacturing is the foundation and pillar of the national economy, and a key support for achieving high-quality development. Advancing the transformation, upgrading, and innovation-driven development of the manufacturing industry is of utmost importance. At present, China has already completed the first phase of its national strategy to become a manufacturing powerhouse ahead of schedule and is steadily advancing toward that long-term goal. However, the road ahead is likely to be shaped by a complex and volatile international environment and intense strategic competition from the United States. This study evaluates China's strategy to become a manufacturing powerhouse from the perspective of …

Garbage Float, Gabor Papp, Max Woolverton, Scott Ulatowski, Daniel Ross, Nicholas Gayle, Bryan Merchan-Aragon, Noah Yco, Nicholas Fawcett, Jared Wright, Abdulaziz Salman G Alshahrani, Andrew Mcquire

Mechanical and Civil Engineering Student Publications

Trash pileup in our waters is an increasing problem. Removing floating plastics and debris from our ecosystem would reduce mortality rate of marine animals. Solutions for this already exist but most of them are proprietary and expensive. Therefore, an autonomous, publicly available and cheap alternative was developed to skim and clean the water surface from garbage.

E-Bike Improvements, Reuben M. Eye, Cole Huddleston, Jeffery Scott, Cade Lewis, Ethan Ridenour

ATU Scholars Symposium

No abstract provided.

Promoting Electric Propulsion (Pep) For Small Craft, Robert Manatt, Brad Fletcher, Hector Campos, Johnathon Poindexter, Quinn Reynolds

ATU Scholars Symposium

The Promoting Electric Propulsion (PEP) For Small Craft event is a competition held every year by the American Society of Naval Engineers (ASNE) and the United States Coast Guard (USCG), and this coming year’s event is being held in Virginia Beach. It is aimed at inspiring students from universities all over the country and allowing them to design innovative fully electrically propelled boats, present their designs and builds, and race them against each other to show off their finished projects. Using fully electric propulsion systems for marine use can be challenging, but if done right they can provide a clean, …

Multi-Rotor Hexicopter, Corbin G. Beard, Payton Riddle, John Washburn, Nate Burckhartzmeyer, Alejandro Gamez

ATU Scholars Symposium

The Multi-Rotor Hexicopter is an original design for an eighteen motor, hydrogen fuel cell powered drone. After initial success with the hydrogen fuel cell powered drone created by previous students, our goal was take their success and create a much larger drone that could be controlled both from the ground and in the air. Our design was based on a drone created by the company Lift Aircraft. The drone is separated into four components that were designed in Autodesk Inventor. The bottom, known as the sled, is used for the storage of the two hydrogen fuel tanks. The second section, …

Radiative Cooling For Energy-Efficient Power Generation, Rickia Hanna

Celebrating Scholarship and Creativity Day (2018-)

This thesis examined radiative cooling on a small scale using a hybrid photovoltaic/radiative cooling model system, to determine its efficiency for large-scale power generation. Radiative cooling is concerned with heat transfer and this thesis’s main goal is to harness that heat energy to produce electricity. The efficiency of the system was tested using various light sources at different angles and total power output. The testing was done several times and there proved to be a proportional relationship between light intensity and current output. However, due to the performance threshold of the PTEC module, the component of the system used to …

Ferroresonance In Three-Phase Electrical Networks, Shavkat Ernstovich Begmatov

Technical science and innovation

Possible modes of ferroresonance in three-phase electric networks and analysis of substitution schemes where ferroresonance voltage increase is observed are considered. The most complete magnetization curve of the transformer core and the analysis of the generalized equivalent substitution scheme are presented, as a result of which more accurate formulas for determining the values of equivalent parameters of the electrical network and voltage transformer in ferroresonance mode are obtained. Factor of ferroresonance voltage increase is introduced, which determines ratio between amplitude values of transformer phase voltage and mains voltage. The method of determination of boundary conditions of steady ferroresonance voltage increase …

Main Prospects Of Natural Gas Purification Technologies From Acidic Compounds, Oybek Yusupdjanovich Aripdjanov, Diyora Zokhid Qizi Khayrullaeva, Jonibek Avazek Ogli Abdumuminov

Technical science and innovation

The article discusses the main prospects for the technology of purifying natural gas from acidic components and the problems of ensuring the purity of oil and gas products in accordance with state standards. An increase in the degree of purification from H₂S, CO₂, elemental sulfur, carbonyl sulfide, ethyl mercaptans (thiols), methyl mercaptan, carbon disulfide, sulfides, disulfides (dithioethers), thiophene, sulfoxides and sulfones is considered. Also, the physicochemical properties of the absorbent for the purification of sulfur compounds (generated during natural gas processing) are studied. Based on the study of various absorbents (ethanolamine (EA), methylethanolamine (MEA), diethanolamine (DEA), …

Analysis Of Close Contact Melting, Mohana Durga Gurunadhan

LSU Master's Theses

This report presents a numerical transient analysis of Close Contact Melting (CCM), intended to help in accurate prediction of melt rate and interface configuration, which is to be utilized for a prospective frozen propellant based propulsion system. Three different substrate shapes namely- Flat, Cylindrical and Wedge, are chosen for the study. The domain discretization is based on generation of boundary fitted mesh and the time varying physical domain is transformed to a fixed computational domain, wherein the associated governing equations are solved. Apart from the conventional linear system solvers, an algebraic multigrid based solver is implemented. A non-iterative implicit/explicit melt …

Energy-Absorbing Helmet For Safer Football, Aidan Laudeman

Honors Theses

Football-related injuries are a common occurrence and are often detrimental to the player’s health. Force impacts frequently occur at the front, back, and sides of a player’s helmet, resulting in head injuries like concussions. The goal of this project is to reduce recurrent head injuries by designing a solution involving the use of energy-absorbing metallic materials that are inserted into a football helmet. These energy-absorbing materials are configured in target zones inside the helmet to reduce the acceleration of the head based on impact locations. The chosen materials are nitinol and spring steel, which display energy-absorbing properties. Various energy-absorbing material …

Hydrogen Fuel Cell Catalyst Test Stand For Single Cell Evaluation, Tyler Johnson

Honors Theses

The main objective of this project was to develop at test stand and relevant testing procedures to aid in ongoing research being conducted by Dr. Ghantasala’s team on platinum-alternative catalyst materials used in proton exchange membrane fuel cells (PEMFCs). To do this, various software (Microsoft Excel, Python, and Simscape) were used to create fuel cell simulations of increasing complexity. These simulations served as baselines for PEMFC evaluation in experimental testing, and they were used to create polarization curves, a standard method for evaluating steady state fuel cell performance. A test stand was also created in order to effectively and efficiently …

Synthesis And Structure-Property Relationships Of Sustainable Nanostructured Materials Towards Energy And Environment Applications, Nizamudeen Alungal Cherupurakal

Thesis/ Dissertation Defenses

This doctoral research aims to advance clean energy technologies by developing specialized nanostructured materials. The study covers significant research themes, each forming separate sections in the thesis, explaining the important role of nanostructures in enhancing the efficiency and sustainability of energy devices and photocatalytic technologies. The enduring effort toward stabilizing and improving the efficiency of dye-sensitized solar cells (DSSCs) has stirred the solar research community to follow innovative approaches. The primary objective of the research is centered on electrode materials design, which improves photoanodes' light-harvesting efficiency (LHE). To improve the Photoanode of DSSCs, a Metal-Organic Framework (MOF) derived porous photoanodes …

Eco-Efficient Coatings For Healthy Indoors: Ozone Deposition Velocities, Primary And Secondary Emissions, Alessandra Ranesi, Paulina Faria, M. Rosario Veiga, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Volatile organic compounds (VOCs) and ozone (O3) are harmful pollutants present in indoor air. Indoor concentrations of VOCs are typically higher than outdoors, due to the presence of indoor sources like building materials and ozone-surface reactions. The study aims to identify and quantify the ozone reactivity and primary and secondary emissions of different indoor coatings. The coatings selected for the study were three gypsum-based plastering mortar, with and without the addition of a bio-waste from Acacia dealbata (raw bark, BA, and bark heated at 250°C, BA250), two clay plasters (one with sand and the other with seashells as additional aggregate), …

Friction Stir Welding Of Tube-To-Tubesheet And Spot Joints For Virgin And Recycled Thermoplastic Materials., Syed Haris Iftikhar

Thesis/ Dissertation Defenses

Thermoplastic materials are becoming popular, due to their chemically inert and anti-fouling properties, for use in industrial heat exchanger applications involving heating/cooling of highly reactive fluids like acids. A novel nonconventional joining framework, based on the friction stir welding (FSW) technique, is developed to create high-quality thermoplastic tube-to-tubesheet joints (TTJs). The proposed technique has applications in the thermoplastic shell-andtube heat exchanger and piping industries (as flange-to-pipe joints). The primary objective is to study the feasibility of the FSW technique for developing thermoplastic TTJs, followed by optimization of the process parameters and detailed material characterizations. This work used workpieces (tube, tubesheet) …

Development Of A Discrete Element Model For Artificial Turf, Justin Rittenhouse

Dissertations

NFL data exhibits a distinct correlation between an elevated lower extremity injury rate and synthetic surfaces. These ubiquitous injuries frequently relate to excessive foot traction (i.e., failure to release causing fracture or soft tissue damage). Consequently, a discrete element model was developed using open-source software to analyze stud traction. First, laboratory data was collected via bench level experiments covering seventeen different testing scenarios. A minimum of twenty-five samples were collected per scenario. Total work, average torque, and maximum torque were used as indicators of stud grip. And the latter two were statistically analyzed for outliers and significant differences. Next, an …

Mechanical Characterization And Evaluation Of Additively Manufactured Titanium 5v-5mo-5al-3cr Alloy, Zachary Casias

Mechanical Engineering ETDs

Ti-5V-5Mo-5Al-3Cr (Ti-5553) is a near beta titanium alloy commonly used in aerospace applications. It is currently being explored for additive manufacturing (AM), but the fatigue behavior of this AM alloy needs to be well-understood for adoption in aerospace applications. The present work examines the tensile and fatigue behavior of LPBF manufactured Ti-5553. The effect of post-print heat treatments, effects of surface roughness, and print defects on the mechanical properties of AM Ti-5553 were also evaluated. Fatigue lives of as-LPBF and BAA material are nearly identical, and both are far below the fatigue lives of conventionally manufactured Ti-5553 of 350 MPa. …