Mechanical Engineering Commons^™

Beach Wheelchair Project, Rory Aronson, Joshua Marcum, Samuel Coyne, Alex Hayes, Alexa Colburn, Max Hessel, Benedikt Strauss, Marvin Rimmele, Marco Pietsch

Mechanical Engineering

The Beach Wheelchair, Sandcrawler, is a machine intended to help give people with disabilities the full beach experience. The non-profit organization Bridge II Sports sponsored this project, and tasked us with developing the design and fabricating a prototype. This chair has several features including a linkage mechanism that raises and lowers a chair relative to an external frame, hand crank drive with Gates Carbondrive belt and sprockets, buoyant Wheeleez balloon tires, and much more.

Rocket Fuel Pressurization, Sean Green, Joe Marcinkowski, Andrew Nahab

Mechanical Engineering

No abstract provided.

Experimental Assessment Of The Impact Of Asymptomatic Gas Emboli On The Vessel Wall, Linxia Gu, Eric L. Cutler

Department of Mechanical and Materials Engineering: Faculty Publications

Quantitative evaluation of shear stress in the vessel wall due to the presence of asymptomatic gas emboli is lacking. The goal of this work was to assess the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis through a custom-built cardiovascular flow simulator. Gas bubbles were created by forced air from a syringe pump. The influences of embolism injection rate, pulse rate, and time-averaged flow rate on the wall mean shear stress were investigated at resting and elevated heart rate conditions. The recorded pressure and volumetric flow rate from 24 experimental settings with four repetitions each were used …

Thickness-Shear And Thickness-Twist Vibrations Of Circular At-Cut Quartz Resonators, Huijing He, Jiashi Yang, Qing Jiang

Department of Mechanical and Materials Engineering: Faculty Publications

Exact solutions for free vibration frequencies and modes are obtained for thickness-shear and thickness-twist vibrations of unelectroded circular AT-cut quartz plates governed by the two-dimensional scalar differential equation derived by Tiersten and Smythe. Comparisons are made with experimental results and the widely-used perturbation solution by Tiersten and Smythe under the assumption of weak in-plane anisotropy. Our solution is found to be much closer to the experimental results than the perturbation solution . For the frequency of the fundamental thickness- shear mode, the error of the perturbation method is 0.4549%, significant in resonator applications.

Conductive Polymer Blends And Their Use In Memory Devices, Mohammad Yousef Al-Haik

Theses

The aim of this project is to synthesize and characterize conductive polymers made out of blending nonconductive polymers with ionic liquids. An application to demonstrate the use of these novel conductive polymers is to create an organic memory device.

Attempts to synthesize conductive polymers have been reported in the literature; several of these approaches include doping a polymer with arsenic or iodine based dopant. In this work, ionic liquids, known as plasticizer, are sued as the dopant for non-conductive polymers. There are several advantages of employing the ionic liquids over other dopants, including the maintenance of organic based blends (both …

Compressive Response Of Polycrystalline Nicomnga High-Temperature Meta-Magnetic Shape Memory Alloys, H. E. Karaca, A. S. Turabi, B. Basaran, A. K. Pathak, I. Dubenko, N. Ali, Y. I. Chumlyakov, P. Li

Mechanical Engineering Faculty Publications

The effects of the addition of quaternary element, Co, to polycrystalline NiMnGa alloys on their magnetic and shape memory properties have been investigated. NiCoMnGa polycrystalline alloys have been found to demonstrate good shape memory and superelasticity behavior under compression at temperatures greater than 100 °C with about 3% transformation strain and low-temperature hysteresis. It is also possible to train the material to demonstrate a large two-way shape memory effect.

Fluid-Structure Interactions With Flexible And Rigid Bodies, David J. Daily

Theses and Dissertations

Fluid structure interactions occur to some extent in nearly every type of fluid flow. Understanding how structures interact with fluids and visa-versa is of vital importance in many engineering applications. The purpose of this research is to explore how fluids interact with flexible and rigid structures. A computational model was used to model the fluid structure interactions of vibrating synthetic vocal folds. The model simulated the coupling of the fluid and solid domains using a fluid-structure interface boundary condition. The fluid domain used a slightly compressible flow solver to allow for the possibility of acoustic coupling with the subglottal geometry …

Performance Of Solid Oxide Iron-Air Battery Operated At 550°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang

Faculty Publications

“Metal-air” batteries have garnered much attention in recent years due to their high intrinsic specific energy and use of inexhaustible and storage-free oxygen source -air- for the “metal-oxygen” reaction. In this study, we report theperformance of a new type of all solid-state “iron-air” battery operated at 550°C. The results show that CeO₂ nanoparticles incorporated into the Fe-Fe₃O₄ redox-couple can improve the specific energy (Wh/kg) and round trip efficiency by 15% and 29%, respectively, over the baseline Fe-Fe₃O₄ battery. Use of supported Fe-Fe₃O₄ nanoparticles as the redox couple can increase the …

A Multiobjective Optimization Method For Collaborative Products With Application To Engineering-Based Poverty Alleviation, Nicholas Scott Wasley

Theses and Dissertations

Collaborative products are created by combining components from two or more products to result in a new product that performs previously unattainable tasks. The resulting reduction in cost, weight, and size of a set of products needed to perform a set of functions makes collaborative products useful in the developing world. In this thesis, multiobjective optimization is used to design a set of products for optimal individual and collaborative performance. This is introduced through a nine step method which simultaneously optimizes multiple products both individually and collaboratively. The method searches through multiple complex design spaces while dealing with various trade-offs …

Micro Modeling Study Of Cathode/Electrolyte Interfacial Stresses For Solid Oxide Fuel Cells, Xinfang Jin, Xingjian Xue

Faculty Publications

Delamination of the cathode/electrolyte interface is an important degradation phenomenon in solid oxide fuel cells (SOFCs). While the thermal stress has been widely recognized as one of the major reasons for such delamination failures, the role of chemical stress does not receive too much attention. In this paper, a micro-model is developed to study the cathode/electrolyte interfacial stresses, coupling oxygen ion transport process with structural mechanics. Results indicate that the distributions of chemical stress are very complicated at the cathode/electrolyte interface and show different patterns from those of thermal stress. The maximum principal stresses take place at the cathode/electrolyte interface …

Studies On Structure And Property Of Polymer-Based Nano-Composite Materials, Yun Zhai

LSU New Orleans Theses and Dissertations

The mixing of polymers and nanoparticles makes it possible to give advantageous macroscopic material performance by tailoring the microstructure of composites. In this thesis, five combinations of nano inclusion and polymer matrix have been investigated.

The first type of composites is titanium dioxide/ polyaniline combination. The effects of 4 different doping-acids on the microstructure, morphology, thermal stability and thermoelectric properties were discussed, showing that the sample with HCl and sulfosalicylic dual acids gave a better thermoelectric property. The second combination is titanium dioxide/polystyrene composite. Avrami equation was used to investigate the crystallization process. The best fit of the mass derivative …

A Mathematical Model For Quantifying System Evolvability Using Excess And Modularity, Morgan Wesley Parry Tackett

Theses and Dissertations

An important factor in system longevity is service-phase evolvability, which is defined as the ability of a system to physically transform from one configuration to a more desirable configuration while in service. These transformations may or may not be known during the design process, and may or may not be reversible. A study of 210 engineered systems was performed and found that system excess and modularity allow a system to evolve while in service. Building on these observations, this thesis introduces mathematical relationships that map a system's excess and modularity to that system's ability to evolve. These relationships are derived …

Using Topology Optimization To Numerically Improve Barriers To Reverse Engineering, Devin Donald Lebaron

Theses and Dissertations

Here explored is a method by which designers can use the tool of topology optimization to numerically improve barriers to reverse engineering. Recently developed metrics, which characterize the time (T) to reverse engineer a product, enable this optimization. A key parameter use din the calculation of T is information content (K). The method presented in this thesis pursues traditional topology optimization objectives while simultaneously maximizing K, and thus T, in the resulting topology. This thesis presents new algorithms to 1) evaluate K for any topology, 2)increase K for a topology by manipulating macro-scale geometry and micro-scale crystallographic information for each …

Micro-Jet Cooling Of Cutting Tools, Douglas J. Woodruff, Gary W. Pannala, William J. Endres, Nicole Barna, Quincy Schultz, David Thomasini, Matthew Zblewski

Michigan Tech Patents

A cutting tool includes an insert defining a flank face, a rake face, and a cutting edge between the flank face and rake face. The cutting tool includes micro-nozzles formed in at least one of the tool body and the insert, and aimed at the cutting edge. Each micro-nozzle generates a micro jet of cutting fluid in close proximity to the cutting edge and adjacent to at least one of the flank face and the rake face.

Floating Electrode Electrowetting On Hydrophobic Dielectric With An Sio2 Layer, Mehdi Khodayari, Benjamin Hahne, Nathan B. Crane, Alex A. Volinsky

Faculty Publications

Floating electrode electrowetting is caused by dc voltage applied to a liquid droplet on the Cytop surface, without electrical connection to the substrate. The effect is caused by the charge separation in the floating electrode. A highly-resistive thermally-grown SiO2 layer underneath the Cytop enables the droplet to hold charges without leakage, which is the key contribution. Electrowetting with an SiO2 layer shows a memory effect, where the wetting angle stays the same after the auxiliary electrode is removed from the droplet in both conventional and floating electrode electrowetting. Floating electrode electrowetting provides an alternative configuration for developing advanced electrowetting-based devices.

An Exploration Of Carbon-Filled Carbon Nanotubes As A Potential Material In Coronary Stents, Kristopher Neil Jones

Theses and Dissertations

The purpose of this research is to explore the potential of using carbon-infiltrated carbon nanotubes (CI-CNT) as a material for coronary artery stents. Stents are commonly fabricated from metal, which may not perform as well as many polymers and ceramics in biomedical applications. Pyrolytic carbon, a ceramic, is currently used in medical implant devices due to its preferrable biocompatibility properties. Micro-patterned pyrolytic carbon devices can be created by growing carbon nanotubes, and then filling the space between with amorphous carbon via chemical vapor deposition. We prepared multiple samples of two different planar stent-like flexible geometries and smaller cubic structures out …

College Of Engineering Senior Design Competition Spring 2013, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Senior Design Experience

Part of every UNLV engineering student's academic experience, the Senior Design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs and prototypes a product in this required element of the curriculum. Working in teams, the senior design project encourages students to use everything learned in the engineering and computer design programs to create a practical, real world solution to an engineering challenge.

Beyond the classroom ...

Because of the requirement to work in teams, students also build good communication skills, presentation skills and even business writing skills. They also have to …

Heterogeneous Relaxation Dynamics In Amorphous Materials Under Cyclic Loading, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Molecular dynamics simulations are performed to investigate heterogeneous dynamics in amorphous glassy materials under oscillatory shear strain. We consider three-dimensional binary Lennard-Jones mixture well below the glass transition temperature. The structural relaxation and dynamical heterogeneity are quantified by means of the self-overlap order parameter and the dynamic susceptibility. We found that at sufficiently small strain amplitudes, the mean square displacement exhibits a broad subdiffusive plateau and the system undergoes nearly reversible deformation over about 104 cycles. Upon increasing strain amplitude, the transition to the diffusive regime occurs at shorter time intervals and the relaxation process involves intermittent bursts of large …

Monte Carlo Uncertainty Analysis For Photothermal Radiometry Measurements Using A Curve Fit Process, Kyle Horne, Austin Fleming, Heng Ban

Utah Space Grant Consortium

Photothermal Radiometry (PTR) has become a popular method to measure thermal properties of layered materials. Much research has been done to determine the capabilities of PTR, but with little uncertainty analysis. This study performs a Monte Carlo uncertainty analysis to quantify uncertainty of film diffusivity and effusivity measurements, presents a sensitivity study for each input parameter, compares linear and logarithmic spacing of data points on frequency scans, and investigates the validity of a 1-D heat transfer assumption.

Assessment Of An Automotive Driving Simulator To Educate Novice Drivers, John Wagner, Qimin Yao, Kim Alexander, Philip Pidgeon

Publications

Novice drivers are more likely to be involved in vehicle crashes than more experienced drivers. Transportation system simulators, such as aerospace, automotive, and rail, have been used effectively over several decades in support of operator training and research studies. The immersive high-end automotive simulators tend to be large-scale, difficult to move, and relatively cost ineffective for widespread deployment. In contrast, a mobile vehicle training system often features simplistic environments which are not readily accepted by teenagers who evaluate the driving experience as compared to commercial video games. Consequently, a need exists for a low-cost portable automotive training system that provides …

Focused Novice Driver Program - Assessment Results And Discussion, John Wagner, Lance Clark, Kim Alexander, Philip Pidgeon, Ken Rogich

Publications

Skills and experiences of novice drivers do not favorably compare to motorists with significantly greater driving time and life experiences. Recent developments in driver education and training have focused on multistage instruction to take advantage of the time delay for driving privileges in Graduated Driver Licensing (GDL) systems as a means to provide additional instruction. A supplemental safe driving program tailored to address the risky behaviors of novice drivers has been developed by Clemson University Automotive Safety Research Institute (CU-ASRI) and the Richard Petty Driving Experience (RPDE). The program offers training in anticipatory safe driving strategies based on the leading …

Design And Construction Of An Experiment For The Investigation Of The Effects Of Gust On Flapping Wing Micro Air Vehicle Power Consumption, Brett Hiller

Mechanical Engineering Undergraduate Honors Theses

In recent years, the promising nature of flapping wing flight has led researchers to investigate the wing morphology and unsteady wing aerodynamics found in insects to aid in the design of modern micro air vehicles (MAVs). A high-fidelity flapping wing MAV could achieve high mobility, hovering stability, increased stealth, and efficient flight at low speeds. These characteristics offer a viable solution to the operational requirements for the typical hazardous and dynamic environments encountered during flight. While the kinematics and morphology of flapping wings are well-understood, significant research has yet to be completed with respect to the control and power requirements …

Optimization Of Automated Temperature Measurement System For Formed Meat Products, Tyler Norman

Mechanical Engineering Undergraduate Honors Theses

The Federal Safety and Inspection Services in accordance with United States Department of Agriculture require that formed meat products be cooked to a specified minimum internal temperature in order to eliminate the possible presence of harmful bacteria. The current system of verifying the internal temperatures of formed meat products consists of manually inserting a temperature probe into the selected sample as it exits the oven. Creating an automated system that measures and records the internal temperatures of formed meat samples as they exit the oven along a meat processing line has been the topic of an ongoing research. The most …

Exploration Into Properties Of Molybdenum Disulfide Using Atomistic Simulation, Joseph Simpson

Mechanical Engineering Undergraduate Honors Theses

Molybdenum disulfide (MoS2) has a lamellar crystal structure, which makes it ideal for use as a solid lubricant. Transmission electron microscope (TEM) images have shown that line defects exist within the lattice of mechanically deformed MoS2, but the physical mechanisms which lead to the formation of these defects are unknown. The two central objectives of this research are to use molecular dynamics simulations to study the effects of tensile deformation on both single layer and bulk MoS2 and explore the properties of line defects in an otherwise perfect lattice of MoS2. Under tensile loading, molecular dynamics simulations show a multi-stage …

Transformable Wheelchair, Benjamin Shurtz

Undergraduate Honors Capstone Projects

This report includes the development, design, and analysis of a transformable wheelchair. There was a need to design and build a wheelchair that transformed to be pushed, pulled, or self-propelled. This design meets the need of physically restricted wheelchair users who frequent simple hiking trails without needing to move to a secondary off-road capable device. Documentation for concepts, analysis, and completed design details follows.

Determining Appropriate Heating And Cooling Thermostat Set Points For Building Energy Simulations For Residential Buildings In North America, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Existing building energy simulation tools have a purported tendency to over-predict heating use and, in some cases, to under-predict cooling use, an outcome often attributed to inappropriate assumptions about thermostat management. As a result, a systematic review was conducted for the purposes of determining typical heating and cooling set points for single-family houses in North America. The preliminary consensus results provide an empirical basis for establishing typical inputs for building energy simulation models, increasing prediction accuracy of heating and cooling loads. The results of this review have been applied as default values in the Lawrence Berkeley National Laboratory's Home Energy …

Analysis And Design Of A Thermal Capacitor For Use In The Food Industry, Karen Nielson

Undergraduate Honors Capstone Projects

Team Hot Stuff is working with Thermal Management Technologies (TMT) of Logan, UT to explore the concept of a thermal capacitor serving platter. With the funding from TMT, Hot Stuff will design, build, and test a prototype serving platter. This report is written by Hot Stuff for MAE 4800, Capstone Design I; it covers the design and analysis of a serving platter.

Helicopter Toy And Lift Estimation, Said Shakerin

All Faculty Articles - School of Engineering and Computer Science

A $1 plastic helicopter toy (called a Wacky Whirler) can be used to demonstrate lift. Students can make basic measurements of the toy, use reasonable assumptions and, with the lift formula, estimate the lift, and verify that it is sufficient to overcome the toy's weight.

Transient Small Wind Turbine Tower Structural Analysis With Coupled Rotor Dynamic Interaction, George R. Katsanis

Master's Theses

Structural dynamics is at the center of wind turbine tower design - excessive vibrations can be caused by a wide range of environmental and mechanical sources and can lead to reduced component life due to fatigue, noise, and impaired public perception of system integrity. Furthermore, periodic turbulent wind conditions can cause system resonance resulting in significantly increased structural loads. Structural vibration issues may become exacerbated in small wind applications where the analytical and experimental resources for system verification and optimization are scarce. This study combines several structural analysis techniques and packages them into a novel and integrated form that can …

Analysis And Mitigation Of The Cubesat Dynamic Environment, Steve M. Furger

Master's Theses

A vibration model was developed for CubeSats inside the Poly-Picosatellite Orbital Deployer (P-POD). CubeSats are fixed in the Z axis of deployers, and therefore resonate with deployer peaks. CubeSats generally start fixed in the X and Y axes, and then settle into an isolated position. CubeSats do not resonate with deployers after settling into an isolated position. Experimental data shows that the P-POD amplifies vibration loads when CubeSats are fixed in the deployer, and vibration loads are reduced when the CubeSats settle into an isolated position. A concept for a future deployer was proposed that isolates CubeSats from the deployer …