Mechanical Engineering Commons^™

A Study On The Effects Of Solar Power, Jonathan Hayes

Electrical Engineering Undergraduate Honors Theses

The utilization of new and alternative energy sources, specifically solar energy, has been on the rise and will continue to grow as we attempt to diminish our use and dependency on older, nonrenewable energy sources. One of the biggest challenges involved with the use of solar energy, or renewable energy in general, is how to provide this energy for general public use. Some of the limiting factors to this are the efficiency in which solar power can be harvested and converted into usable energy, and the cost of the technology to do this. Recent technological developments have included the microinverter, …

Thromboresistance Characterization Of Extruded Nitric Oxide Releasing Silicone Catheters, Kagya Amoako, Christopher Archangeli, Hitesh Handa, Terry Major, Mark E. Meyerhoff, Gail M. Annich, Robert H. Bartlett

Mechanical and Industrial Engineering Faculty Publications

Intravascular catheters used in clinical practice can activate platelets, leading to thrombus formation and stagnation of blood flow. Nitric oxide (NO)-releasing polymers have been shown previously to reduce clot formation on a number of blood contacting devices. In this work, trilaminar NO-releasing silicone catheters were fabricated and tested for their thrombogenicity. All catheters had specifications of L = 6 cm, inner diameter = 21 gauge (0.0723 cm), outer diameter = 12 gauge (0.2052 cm), and NO-releasing layer thickness = 200 ± 11 µm. Control and NO-releasing catheters were characterized in vitro for their NO flux and NO release duration by …

Energy Consumption And Greenhouse Gas Emissions From Commercial And Manufacturing Sectors Specific Studies On Hvac Equipment And Dairy Processing, Aik Jong Tan

Graduate Theses and Dissertations

Commercial and manufacturing sectors in United States consumed approximately 50% of the total End use energy in 2010. In 2009, 81.5% of the greenhouse gas (GHG) emitted in the United States was energy related. From the broad aspects of commercial and manufacturing sectors; two relatively narrow and specific topics, commercial building's HVAC equipment and dairy processing were chosen to increase the understanding of the energy use and GHG emission in these two sectors. Few published studies related to these two specific areas are available. The first study in this thesis discussed the energy use and GHG emissions by HVAC equipment …

Computer Modeling Of The Influence Of Structure Plan Areas On Tornado Forces, Nashmi Hassan M Alrasheedi

Graduate Theses and Dissertations

The study of the conventional Straight Line (SL) wind flow dominates research into wind loads on structures. Most structure design takes into account only research into SL flow. Few researchers have studied tornado forces on buildings and attempted to distinguish between tornadic wind loads and SL flow loads. Using a computer simulation, this research addresses and distinguishes between the tornadic forces and SL forces on structures. In the numerical simulation, tornado forces and SL forces will be compared on large structure plan areas and on thin structure plan areas. Additionally this research investigates how the increase in the vortex strength …

Design And Implementation Of A Small Electric Motor Dynamometer For Mechanical Engineering Undergraduate Laboratory, Aaron Farley

Graduate Theses and Dissertations

This thesis set out to design and implement a new experiment for use in the second lab of the laboratory curriculum in the Mechanical Engineering Department at the University of Arkansas in Fayetteville, AR. The second of three labs typically consists of data acquisition and the real world measurements of concepts learned in the classes at the freshman and sophomore level. This small electric motor dynamometer was designed to be a table top lab setup allowing students to familiarize themselves with forces, torques, angular velocity and the sensors used to measure those quantities, i.e. load cells and optical encoders. The …

Design Of Orbital Maneuvers With Aeroassisted Cubesatellites, Stephanie Clark

Graduate Theses and Dissertations

Recent advances within the field of cube satellite technology has allowed for the possible development of a maneuver that utilizes a satellite's Low Earth Orbit (LEO) and increased atmospheric density to effectively use lift and drag to implement a noncoplanar orbital maneuver. Noncoplanar maneuvers typically require large quantities of propellant due to the large delta-v that is required. However, similar maneuvers using perturbing forces require little or no propellant to create the delta-v required. This research reported here studied on the effects of lift on orbital changes, those of noncoplanar types in particular, for small satellites without orbital maneuvering thrusters. …

Study Of Grinding Burn Using Design Of Experiments Approach And Advanced Kaizen Methodology, Kiruthika Devi Sundarrajan

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Grinding burn has been one of the re-occurring issues at a leading automotive manufacturer. Historically when grinding burn occurred, trial and error was used to delicately find a set up process settings that provided good-enough-to-get-by results, but not optimal. Some changes include changing the coolant manifold to improve the coolant flow and rate, changing the grinding wheel, changing the type of coolant. The experiments have proved to introduce some improvements, however the occurrence of grinding burns have not been reduced or quantified and the cause of the grinding burn has not been identified or quantified. Grinding is a complex phenomenon …

Implementation Of Wireless Temperature Sensors For Continuous Condition Monitoring Of Railroad Bearings, Andoni Zagouris Ii

Theses and Dissertations - UTB/UTPA

At present there are no existing bearing health monitoring systems capable of continuous monitoring of railroad bearings. Current wayside equipment is used to collect intermittent bearing temperatures, which at times could be every 65 km (~40 mi). To answer this need, IONX, LLC, a subsidiary of Amsted Rail, Inc., has developed low power Wireless Sensor Nodes (WSNs) which can be retrofitted to existing bearing adapters. The WSNs provide continuous monitoring of bearing temperatures as well as the current ambient temperature. Since the nodes are affixed to the bearing adapter surface, a correlation is necessary to estimate the bearing cup temperature …

Effects Of Surface Roughness On The Indoor Particle Deposition Rate Constant, Shaojie Wang

Mechanical and Aerospace Engineering - Dissertations

The purpose of this work was to quantify the deposition rate constants of size-classified particles on typical indoor surface materials as affected by the degree of surface roughness. The experiments were conducted in a small-scale acrylic chamber. The particle size range was from 0.723 to 5.048 £gm with 28 size bins. The air change rates were 6, 11 and 13 h-1. The TSI large particle aerosol generator 8108 was used to generate potassium chloride as test particles, and the TSI aerodynamic particle sizer (APS3321) was used to measure the particle number concentrations. Particle deposition rate constants were determined by regression …

A Double Cantilever Beam Specimen For Foam Core Fracture Characterization, Elio E. Saenz, Adrián Hernández-Pérez, Leif A. Carlsson, Anette M. Karlsson

Mechanical Engineering Faculty Publications

This article presents the analysis and test results for a new sandwich double cantilever beam specimen for foam fracture characterization. The foam is sandwiched between two stiff and strong aluminum adherends. The specimen is analyzed using a modified version of the classical Kanninen elastic foundation model. Finite element analysis is conducted to determine the stress state near the crack tip and compliance of the double cantilever beam sandwich specimen. Model predictions are compared to experimental compliance data and crack growth paths for double cantilever beam specimens with polyvinyl chloride and polyethersulfone foams. The elastic foundation model and finite element analysis …

Finite Element Modeling And Design Of Honeycomb Sandwich Panels For Acoustic Performance, David Griese

All Theses

Honeycomb cellular metamaterial structures offer many distinct advantages over homogenous materials because their effective material properties depend on both their constituent material properties and their geometric cell configuration. From this, a wide range of targeted effective material properties can be achieved thus supporting forward design by tailoring the honeycomb cellular materials and properties for specific applications. One area that has not been fully explored is the set of acoustic properties of honeycomb materials and how these can offer increased design flexibility when targeting acoustic performance. Understanding these relations, the designer can effectively tune designs to perform better in specific acoustic …

Sole Power: Pedal Phone Charger Final Report, Nicole Hensley, Anthony Ruh, Krista Schmidt, Joseph Garcia

Mechanical Engineering

The device design was conceived to meet the energy needs of rural populations in India. These communities have cell phones but lack access to reliable grid power, especially during monsoon season. The charger is designed to be affordable, durable, and easily repairable for each owner family. It uses off-the-shelf components and is intended to be replicated by backyard manufacturing startups in developing countries.

Its purpose is to efficiently transfer human foot motion via a treadle, four-bar-linkage, and sprocket-chain step-up to drive a rotor & stator generator from a common gas scooter. The single-phase alternating current from the generator is passed …

Phase Resolved Near-Field Mode Imaging For The Design Of Frequency-Selective Surfaces, Edward C. Kinzel, J. C. Ginn, R. L. Olmon, D. J. Shelton, B. A. Lail, I. Brenner, M. B. Sinclair, M. B. Raschke, G. D. Boreman

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Reduction Of Solid-Solid Thermal Boundary Resistance By Inserting An Interlayer, Zhi Liang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An Effective Method is Proposed to Greatly Improve the Thermal Transport Across the Interface between Two Solids with Dissimilar Phonon Spectra. If the Two Solids Have Similar Crystal Structure and Lattice Constant, It is Predicted from the Molecular Dynamics Modeling that an over 50% Reduction of the Thermal Boundary Resistance Can Be Achieved by Inserting a 3-Unit-Cell-Thick Interlayer Whose Debye Temperature is Approximately the Square Root of the Product of the Debye Temperatures of the Two Solids. on the Other Hand, If the Two Solids Have a Large Difference in Lattice Constant, It is Found the Interfacial Atomic Restructuring Plays …

Improving Health Care Quality And Safety: The Development And Assessment Of Laparoscopic Surgery Instrumentation, Practices And Procedures, Bernadette Mccrory

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Adverse events due to medical errors are a leading cause of death in the United States exceeding the mortality rates of motor vehicle accidents, breast cancer and AIDS. Improvements can and should be made to reduce the rates of preventable surgical errors since they account for nearly half of all adverse events within hospitals. Although minimally invasive surgery has proven patient benefits such as reduced postoperative pain and hospital stay, its operative environment imposes substantial physical and cognitive strain on the surgeon increasing the risk of error. In order to mitigate errors and protect patients, a multidisciplinary approach was taken …

Material Handling System For Robotic Natural Orifice Surgery, Jeff Midday

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Natural Orifice Translumenal Endoscopic Surgery (NOTES) is a relatively new surgical approach which uses no external incisions, thereby improving cosmetic outcomes, decreasing overall recovery time and reducing the risk of external infection. In standard NOTES, flexible endoscopic tools have been used to carry out a variety of surgical procedures in the abdomen. As an alternative, miniature in vivo robots can be fully inserted into the peritoneal cavity and utilized to perform various surgical procedures. These in vivo robots eliminate tool triangulation issues, improve multi-tasking capabilities and greatly increase freedom and dexterity when compared to standard endoscopic and laparoscopic tools. One …

The Integration Of Propane Flaming And Mechanical Cultivation For Effective Weed Control In Agriculture, Brian D. Neilson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Flaming is a thermal weed control method that can kill weeds within or between crop rows using heat. Mechanical cultivation is another weed control method which undercuts weeds between crop rows to kill them. A combination flamer/cultivator implement was designed to take advantage of the good qualities of both flaming and cultivation to provide excellent organic weed control.

Flaming hoods were designed in the spring of 2010 and retrofitted on an existing row crop cultivator. The hoods were tested in corn and soybean field studies in the summer of 2010. Of the seven treatments tested, a treatment of flaming combined …

Streambed Thermal Property Instrument (Spi), James Alwel Dayie

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The purpose of this research, the Streambed thermal Property Instrument (SPI) is to determine the applicability of this instrument for in situ thermal (conductivity and diffusivity) and porous flow (magnitude and direction) measurements. Currently, no such thermal instrument exists for such in situ measurements and the reason for developing this unique instrument, the SPI to fill the technology gap in sediment thermal property measurement devices. Prior to testing the instrument under controlled laboratory conditions to determine its functionality through a series of static and flow tests, the instrument was designed and built. A lab-sized version of an actual river called …

Novel Heavy Duty Engine Concept For Operation Dual Fuel H 2-Nh3, Alberto A. Boretti

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A prior paper has presented a novel design of a heavy-duty truck engine fueled with H2. in this design, the customary in-cylinder Diesel injector and glow plug are replaced with a main chamber fuel injector and a jet ignition pre-chamber. the jet ignition pre-chamber is a small volume that is connected to the in-cylinder through calibrated orifices accommodating another fuel injector and a glow or a spark plug that controls the start of combustion. This design permits to operate the engine in four different modes: traditional compression ignition (CI), diffusion, Diesel-like (M1); mixed gasoline/Diesel-like (M2); traditional spark ignition (SI), premixed, …

Thermally Aware, Energy-Based Techniques For Improving Data Center Energy Efficiency, Dustin W. Demetriou

Mechanical and Aerospace Engineering - Dissertations

This work investigates the practical implementation of so-called thermally aware, energy optimized load placement in air-cooled, raised floor data centers to reduce the overall energy consumption, while maintaining the reliability of the IT equipment. The work takes a systematic approach to modeling the data center's airflow, thermodynamic and heat transfer characteristics - beginning with simplified, physics-inspired models and eventually developing a high-fidelity, experimentally validated thermo-hydraulic model of the data center's cooling and power infrastructure. The simplified analysis was able to highlight the importance of considering the trade-off between low air supply temperature and increased airflow rate, as well as the …

Modeling And Managing Engineering Changes In A Complex Product Development Process, Weilin Li

Mechanical and Aerospace Engineering - Dissertations

Today's hyper-competitive worldwide market, turbulent environment, demanding customers, and diverse technological advancements force any corporations who develop new products to look into all the possible areas of improvement in the entire product lifecycle management process. One of the areas that both scholars and practitioners have overlooked in the past is Engineering Change Management (ECM).

The vision behind this dissertation is to ultimately bridge this gap by identifying main characteristics of a New Product Development (NPD) process that are potentially associated with the occurrence and magnitude of iterations and Engineering Changes (ECs), developing means to quantify these characteristics as well as …

Perceptions Measurement Of Professional Certifications To Augment Buffalo State College Baccalaureate Technology Programs, As A Representative American Postsecondary Educational Institution, Christopher N. Brown

Industrial Technology Theses

The purpose of this study was to assess, measure, and analyze whether voluntary, nationally-recognized professional certification credentials were important to augment technology programs at Buffalo State College (BSC), as a representative postsecondary baccalaureate degree-granting institution offering technology curricula. Six BSC undergraduate technology programs were evaluated within the scope of this study: 1.) Computer Information Systems; 2.) Electrical Engineering, Electronics; 3.) Electrical Engineering, Smart Grid; 4.) Industrial Technology; 5.) Mechanical Engineering; and 6.) Technology Education. This study considered the following three aspects of the problem: a.) postsecondary technology program enrollment and graduation trends; b.) the value/awareness of professional certifications to employers …

Polycart, Ryan Bolton, Vincent Contreras, Rodrigo Sanchez

Mechanical Engineering

No abstract provided.

Adding Cerebral Autoregulation To A Lumped Parameter Model Of Blood Flow, Russell Gentile

HIM 1990-2015

A mathematical model of blood flow in infants with hypoplastic left heart syndrome (HLHS) was improved by adding cerebral autoregulation. This is the process by which blood vessels constrict or dilate to keep blood flow steady in certain organs during pressure changes. The original lumped parameter model transformed the fluid flow into an electrical circuit. Its behavior is described using a system of thirty-three coupled differential equations that are solved numerically using a fourth-order Runge-Kutta method implemented in MATLAB. A literature review that includes a discussion of autoregulation mechanisms and approaches to modeling them is followed by a description of …

Clustering And Classification Of Multivariate Stochastic Time Series In The Time And Frequency Domains, Ryan Schkoda

All Dissertations

The dissertation primarily investigates the characterization and discrimination of stochastic time series with an application to pattern recognition and fault detection. These techniques supplement traditional methodologies that make overly restrictive assumptions about the nature of a signal by accommodating stochastic behavior. The assumption that the signal under investigation is either deterministic or a deterministic signal polluted with white noise excludes an entire class of signals -- stochastic time series. The research is concerned with this class of signals almost exclusively. The investigation considers signals in both the time and the frequency domains and makes use of both model-based and model-free …

Heater Geometry And Heat Flux Effects On Subcooled, Thin Wire, Nucleate Pool Boiling In Microgravity, Troy Munro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis is to study the effects of microgravity, surface geometry, and heat dissipation per unit area (heat flux) on boiling heat transfer. Boiling is able to move a significant amount of heat for a small area in comparison to other heat transfer methods. Space systems could benefit from the development of thermal management systems that use boiling heat transfer because they would be smaller, more robust, and less expensive. However, boiling is an extremely complicated process which has no comprehensive models to predict its behavior. Multiple correlations have been developed which relate heat transfer efficiencies to …

Comparative Fatigue Analysis Of Metals And Polymers For Engineering Applications, Monica Jones

Mechanical Engineering Undergraduate Honors Theses

Rapid prototype polymers are becoming increasingly popular for engineering applications, particularly during the design phase as a quick check for size and fit; however they are not currently widely-used for load-bearing applications. Current research at the University of Arkansas Department of Mechanical Engineering focused on rapid prototyped polymers by doing cyclical tensile testing. The results were analyzed for strain energy and fatigue data. When cycling at lower percentages of ultimate stress, unusual strain energy patterns were observed. This research details testing of metals in order to compare strain energy patterns to those of the rapid prototype polymers.

Enhanced Tribological Properties Of Surfaces Patterned With Dlc/Su8 Microstructures, Luke Osborn

Mechanical Engineering Undergraduate Honors Theses

Textured surfaces can reduce friction due to decreased contact area between two surfaces, and could therefore increase the reliability of micro-electro-mechanical systems (MEMS). The problem with some microtextures is their inability to withstand significant amounts of wear, often deforming or breaking, thus limiting their potential uses and overall effectiveness. In this study, connected and isolated SU8 microstructures with and without diamond-like coating (DLC) were designed to investigate the effects of these microstructures on the tribological performance of a surface. Friction studies were conducted using a tribometer, while surface topography and wear were characterized by scanning electron microscopy (SEM), optical microscope, …

Design And Use Of An Alternative Fuel Testing Apparatus And Assessment Of The Feasibility Of Biodiesel, Matthew Tanner

Master’s Theses

Petroleum supply and environmental pollution issues constantly increase interest in renewable low polluting alternative fuels. Published test results show decreased pollution with similar power output and fuel consumption from Internal Combustion Engines (ICE) burning alternative fuels. More specifically, diesel engines burning biodiesel derived from plant oils and animal fats not only reduce harmful exhaust emissions but are renewable and environmentally friendly. To validate these claims and assess the feasibility of alternative fuels, independent engine dynamometer and emissions testing was performed. A testing apparatus capable of making relevant measurements was designed, built, and used to test and determine the feasibility of …

Assessing The Engineering Performance Of Affordable Net-Zero Energy Housing, Jordan P. Wallpe

Purdue Polytechnic Masters Theses

The purpose of this research was to evaluate affordable technologies that are capable of providing attractive, cost-effective energy savings to the housing industry. The research did so by investigating the 2011 Solar Decathlon competition, with additional insight from the Purdue INhome. Insight from the Purdue INhome verified the importance of using a three step design process to design a net-zero energy building. In addition, energy consumption values of the INhome were used to compare and contrast different systems used in other houses.

Evaluation of unbiased competition contests gave a better understanding of how a house can realistically reach net-zero. Upon …