Mechanical Engineering Commons^™

Numerical Simulation And Optimization Of Carbon Dioxide Utilization And Storage In Enhanced Gas Recovery And Enhanced Geothermal Systems, James H. Biagi

McKelvey School of Engineering Theses & Dissertations

With rising concerns surrounding CO₂ emissions from fossil fuel power plants, there has been a strong emphasis on the development of safe and economical Carbon Capture Utilization and Storage (CCUS) technology. Two methods that show the most promise are Enhanced Gas Recovery (EGR) and Enhanced Geothermal Systems (EGS). In Enhanced Gas Recovery a depleted or depleting natural gas reservoir is re-energized with high pressure CO₂ to increase the recovery factor of the gas. As an additional benefit following the extraction of natural gas, the reservoir would serve as a long-term storage vessel for the captured carbon. CO_{2 …}

An Approach To Thermocouple Temperature Measurements That Reduces Uncertainties Associated With Radiative Corrections, Siddharth Krishnan

McKelvey School of Engineering Theses & Dissertations

Obtaining accurate temperature measurements in flame environments with thermocouples is extremely challenging due to the effects of radiative heat loss. These losses are difficult to quantify and often cannot be corrected for or minimized without sacrificing spatial resolution. In this work, a new experimental methodology is presented that has shown potential to minimize the temperature correction by both increasing and controlling the effects of convection. This is accomplished through high speed rotation of the thermocouple. The rotation yields a high and known convective velocity over the thermocouple. Heat transfer can then be modeled for the thermocouple, and a functional relationship …

Systematic Approach For Modeling Methanol Mass Transport On The Anode Side Of Direct Methanol Fuel Cells, Mohammad Biswas

Mohammad Biswas

A Novel Intermediate-Temperature All Ceramic Iron–Air Redox Battery: The Effect Of Current Density And Cycle Duration, Xuan Zhao, Xue Li, Yunhui Gong, Nansheng Xu, Kevin Huang

Faculty Publications

We here report the energy storage characteristics of a new all ceramic iron–air redox battery comprising of a reversible solid oxide fuel cell as the charger/discharger and a Fe–FeO_x redox couple as the chemical storage bed. The effects of current density and cycle duration on specific energy and round trip efficiency of the new battery have been systematically studied at 650°C and 550°C. The results explicitly show that current density is the most influential variable on the performance, signifying the importance of improving electrochemical performance of the reversible solid oxide fuel cell.

Handloaded Rifle Ammunition: A Look Into The Assembly Process, Load Development Methods, And Its Comparison To Factory Ammunition, Jeffrey Dalton Snyder

Senior Theses

The purpose of this thesis is to educate the reader on the appeal of assembling firearm ammunition from its individual components, a process known as “handloading,” in comparison to factory assembled ammunition. This is accomplished by providing the reader with the benefits of handloading with an overview of the handloading process. Then, an example of a handload development method (Ladder Test) is discussed and performed. The results from the test are then analyzed and explained. Finally, the handloaded ammunition from the test is compared by function and price to factory ammunition from three different market segments.

The project portion of …

Design And Construction Of A Chemical Engineering (Cheme) Car Using Thermoelectrics, Timothy Barnhill, Sara Davino, Spencer Faltin, Lauryn Jamison, Christina Papadimitrio, Mccall Rogers

Senior Theses

Six chemical engineering undergraduates at the University of South Carolina formed a team to compete in the 2014 AIChE Chem-E-Car competition at the Southern Regional Student Conference in San Juan, Puerto Rico, in March. In the Chem-E-Car competition, students must design and build a vehicle powered by an unconventional form of chemical energy to carry a specified weight over a given distance (1). The group used knowledge gained through undergraduate study to construct a small-scale vehicle that is powered by a set of thermoelectric generators utilizing a heat gradient between boiling water and an ethanol-dry ice mixture (2). An iodine …

College Of Engineering Senior Design Competition Spring 2014, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

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. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

Characterization Of 3d Interconnected Microstructural Network In Mixed Ionic And Electronic Conducting Ceramic Composites, William M. Harris, Kyle S. Brinkman, Ye Lin, Dong Su, Alex P. Cocco, Arata Nakajo, Matthew B. Degostin, Yu-Chen Karen Chen-Wiegart, Jun Wang, Fanglin Chen, Yong S. Chu, Wilson K. S. Chiu

Faculty Publications

The microstructure and connectivity of the ionic and electronic conductive phases in composite ceramic membranes are directly related to device performance. Transmission electron microscopy (TEM) including chemical mapping combined with X-ray nanotomography (XNT) have been used to characterize the composition and 3-D microstructure of a MIEC composite model system consisting of a Ce_0.8Gd_0.2O₂ (GDC) oxygen ion conductive phase and a CoFe₂O₄ (CFO) electronic conductive phase. The microstructural data is discussed, including the composition and distribution of an emergent phase which takes the form of isolated and distinct regions. Performance implications are considered …

Piezoresistive Sensing Of Bistable Micro Mechanism State, Jeffrey K. Anderson, Larry L. Howell, Jonathan W. Wittwer, Timothy W. Mclain

Faculty Publications

The objective of this work is to demonstrate the feasibility of on-chip sensing of bistable mechanism state using the piezoresistive properties of polysilicon, thus eliminating the need for electrical contacts. Changes in position are detected by observing changes in resistance across the mechanism. Sensing the state of bistable mechanisms is critical for various applications, including high-acceleration sensing arrays and alternative forms of nonvolatile memory. A fully compliant bistable micro mechanism was designed, fabricated, and tested to demonstrate the feasibility of this sensing technique. Testing results from two fabrication processes, SUMMiT IV and MUMPs, are presented. The SUMMiT mechanism was then …

V&V Exercise For A Solar Tower Power Plant, Nima Fathi, Seyed Sobhan Aleyasin, Peter Vorobieff

Nima Fathi

Bi-Directional Variable Stiffness Magnetorheological Elastomer (Mre) Design, Sarah S. Trabia

College of Engineering: Graduate Celebration Programs

What is MRE?
•MRE is a semi-active silicon with embedded iron particles for variable stiffness changes under external magnetic flux

Research Objective
•Feasibility of using MRE as a haptic feedback device.
•Design a MRE device that can increase or decrease the stiffness.
•Design an effective way of providing a “pre-strain” to the base silicon material.

Computational Simulation
•COMSOL 4.3b Finite Element Analysis
•2D axisymmetric model
•Parametric sweep was run to find the amount of current needed to counteract the permanent magnet.

Investigation Of Phase Change In A36 Steel As A Result Of High Velocity Impact Loading, Mena Slewa

College of Engineering: Graduate Celebration Programs

High velocity projectiles cause severe damage to target materials upon impact. The target material is subject to high pressure and temperature over a very short period of time. This work studies the effects of Lexan projectiles impacting A36 steel at velocities between 3 km/sec and 6 km/sec. The damage zone develops in the target within 5 microseconds. Some steel materials go through a reversible phase change when subject to elevated temperature and high quasi-static pressure. It is unknown whether A36 steel experiences this phase change during high velocity impact. The objective of this work is to investigate if any permanent …

Computational Feasibility Study Of Dual Photon/Neutron Imaging Technique, Jessica Hartman, Alexander Barzilov

College of Engineering: Graduate Celebration Programs

• Non-destructive testing (NDT) is crucial for industrial applications, particularly when imaging of internal components or structures is desired

• Current NDT imaging techniques, such as x-rays, focus primarily on isolating unique shapes. Rarely are these methods capable of distinguishing materials or material composition

• Potential application in the car industry for testing and examining the functional durability of products
  − Vehicle engines are composed of a combination of low-z and high-z materials with significant variation in density
  − Being able to determine the location of material during operation eliminates the need to disassemble an engine during study

Computational Analysis Of Hybrid Norwood Circulation With Distal Aortic Arch Obstruction And Reverse Blalock-Taussig Shunt, Andres Ceballos, I. Ricardo Argueta-Morales, Eduardo Divo, Ruben Osorio, Christopher A. Caldarone, Alain J. Kassab, William M. Decampli

Eduardo Divo

BACKGROUND: The hemodynamics characteristics of the hybrid Norwood (HN) procedure differ from those of the conventional Norwood and are not fully understood. We present a multi-scale model of HN circulation to understand local hemodynamics and effects of aortic arch stenosis and a reverse Blalock-Taussig shunt (RBTS) on coronary and carotid perfusion. METHODS: Four 3-dimensional models of four HN anatomic variants were developed, with and without 90% distal preductal arch stenosis and with and without a 4-mm RBTS. A lumped parameter model of the circulation was coupled to a local 3-dimensional computational fluid dynamics model. Outputs from the lumped parameter model …

An Inverse Pod-Rbf Network Approach To Parameter Estimation In Mechanics, Craig A. Rogers, Alain Kassab, Eduardo Divo, Ziemowit Ostrowski, Ryszard Bialecki

Eduardo Divo

An inverse approach is formulated using proper orthogonal decomposition (POD) integrated with a trained radial basis function (RBF) network to estimate various physical parameters of a specimen with little prior knowledge of the system. To generate the truncated POD-RBF network utilized in the inverse problem, a series of direct solutions based on FEM, BEM or exact analytical solutions are used to generate a data set of temperatures or deformations within the system or body, each produced for a unique set of physical parameters. The data set is then transformed via POD to generate an orthonormal basis to accurately solve for …

Computational Fluid Dynamics In Congenital Heart Disease, William M. Decampli, I. Ricardo Argueta-Morales, Eduardo Divo, Alain J. Kassab

Eduardo Divo

Computational fluid dynamics has been applied to the design, refinement, and assessment of surgical procedures and medical devices. This tool calculates flow patterns and pressure changes within a virtual model of the cardiovascular system. In the field of paediatric cardiac surgery, computational fluid dynamics is being used to elucidate the optimal approach to staged reconstruction of specific defects and study the haemodynamics of the resulting anatomical configurations after reconstructive or palliative surgery. In this paper, we review the techniques and principal findings of computational fluid dynamics studies as applied to a few representative forms of congenital heart disease.

Mechanics Of Hip Dysplasia Reduction In Infants Using The Pavlik Harness: A Physics Based Computational Model, Orlando Ardila, Eduardo Divo, Faissal Moslehy, George Rab, Alain Kassab, Charles Price

Eduardo Divo

Biomechanical factors influencing the reduction of dislocated hips with the Pavlik harness in patients of Developmental Dysplasia of the Hip (DDH) were studied using a three-dimensional computer model simulating hip reduction dynamics in (1) subluxated and (2) fully dislocated hip joints. Five hip adductor muscles were identified as key mediators of DDH prognosis, and the non-dimensional force contribution of each in the direction necessary to achieve concentric hip reductions was determined. Results point to the adductor muscles as mediators of subluxated hip reductions, as their mechanical action is a function of the degree of hip dislocation. For subluxated hips in …

Design And Experimental Testing Of Nanoinjection Protocols For Delivering Molecules Into Hela Cells With A Bio-Mems Device, Zachary Kendall Lindstrom

Theses and Dissertations

Delivering foreign molecules into living cells is a broad and ongoing area of research. Gene therapy, or delivering nucleic acids into cells via non-viral or viral pathways, is an especially promising area for pharmaceutics. All gene therapy methods have their respective advantages and disadvantages, including limited delivery efficiency and low viability. Nanoinjection, or delivering molecules into cells using a solid lance, has proven to be highly efficient while maintaining high viability levels. In this thesis, an array of solid silicon lances was tested by nanoinjecting tens of thousands of HeLa cancer cells simultaneously. Several molecule types were injected in different …

Measurement Of The Rate Of Hydrogen Peroxide Thermal Decomposition In A Shock Tube Using Quantum Cascade Laser Absorption Near 7.7 Μm, M. B. Sajid, Et. Es-Sebbar, T. Javed, C. Fittschen, A. Farooq

Dr. Et-touhami Es-sebbar

Hydrogen peroxide (H2O2) is formed during hydrocarbon combustion and controls the system reactivity under intermediate temperature conditions. Here, we measured the rate of hydrogen peroxide decomposition behind reflected shock waves using midinfrared absorption of H2O2 near 7.7 µm. We performed the experiments in diluted H2O2/Ar mixtures between 930 and 1235 K and at three different pressures (1, 2, and 10 atm). Under these conditions, the decay of hydrogen peroxide is sensitive only to the decomposition reaction rate, H2O2 + M → 2OH + M (k1). The second-order rate coefficient at low pressures (1 and 2 atm) did not exhibit any …

Fixed Platform Crane For Equipment Access, Carlos Gonzalez, Steven Hollander, Yue Zhao, Jared Pellegrin, Travis Odom

Honors Theses

No abstract provided.