Engineering Commons^™

Characterization & Extraction Of Extracellular Matrix From Porcine Adipose Tissue, Rahulkumar Kantibhia Bhoi

Open Access Theses & Dissertations

Tissue in particular extracellular matrix(ECM) plays a vital role in the growth and the function of each cell types and promote tissue regeneration and repair an impair organs. Many techniques have been developed so far to decellularized porcine tissue for the purpose to use as regenerative medicine and in tissue engineering. We aimed to optimized a method to decellularized porcine tissue while effectively eliminating xenogeneic epitopes, lipids and to retain necessary component of it intact without disrupting ECM. We have developed 2-week protocol to optimize well preserved ECM component that may keep xenogeneic biomaterial for tissue engineering and regenerative medicine. …

Theoretical Acoustic Absorber Design Approach For Lox/Lch4 Pintle Injector Rocket Engines, Jonathan Candelaria

Open Access Theses & Dissertations

Liquid rocket engines, or LREs, have served a key role in space exploration efforts. One current effort involves the utilization of liquid oxygen (LOX) and liquid methane (LCH4) LREs to explore Mars with in-situ resource utilization for propellant production. This on-site production of propellant will allow for greater payload allocation instead of fuel to travel to the Mars surface, and refueling of propellants to travel back to Earth. More useable mass yields a greater benefit to cost ratio. The University of Texas at El Paso's (UTEP) Center for Space Exploration and Technology Research Center (cSETR) aims to further advance these …

Advances In Chemical Vapor Deposition Growth Of Molybdenum Disulfide For Photodetectors And Flexible Electronics, Carlos Francisco De Anda Orea

Open Access Theses & Dissertations

The conversion of light into electrical signals is at the basis of technologies that affect our daily lives. Applications, including video imaging, optical communications, biomedical imaging, security, night-vision, gas sensing and motion detection have reached a high level of maturity due to the development of high-performance materials, large-scale production, and integration technologies. Currently conventional photodetectors made of Silicon (Si) or III-V compounds are about to reach their maximum efficiency, and every time it is harder to get a noticeable improvement in performance of sensors based on these materials, not to mention the complicated fabrication methods to achieve just a few …

The Development Of A Data Acquisition And Control System For Rocket Propulsion Research, Javier Chaparro

Open Access Theses & Dissertations

The MIRO Center for Space Exploration Technology Research (cSETR) at the University of Texas at El Paso (UTEP) has developed the Technology Research and Innovation Acceleration Park (tRIAC) in Fabens, Texas. This facility has been established in order to meet new research demands for experimental testing of Liquid Oxygen (LOX)/Liquid methane (LCH4) propulsion systems. Within this facility, a vertical test stand capable of measuring up to 3,000lbf will be constructed for main engine testing of the JANUS and DAEDALUS vehicle programs.

In order to meet challenges of precise remote system operation and data acquisition during engine testing, cSETR designed and …

Methods For Producing Graphene From Petroleum By-Products, Eva M. Deemer

Open Access Theses & Dissertations

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Quantifying The Characteristic Length Of A Combustor For An Ionic Liquid Monopropellant Thruster, Kimberly Marie Hogge

Open Access Theses & Dissertations

Ionic liquid monopropellants are currently being researched as a promising alternative to hydrazine in propulsion systems. This report presents a flame study that delineates the flame length of the expected decomposition products from an ionic liquid monopropellant. Through these studies, the characteristic length of a combustion chamber will be defined through calculations and empirical correlations. There is limited information on designing a propulsion system for an ionic liquid monopropellant. Therefore, defining the magnitude for an effective characteristic length serves as beneficial in designing a propulsion system for an ionic liquid monopropellant thruster.

Microstructure And Mechanical Properties Of Sputter-Deposited Nanocrystalline W1-Ymoyo3 Thin Films, Gabriel Lopez

Open Access Theses & Dissertations

Currently, there is a wide-spread interest in the design and development of indium (In) free transparent conductive oxides (TCOs) for utilization in photovoltaics and optoelectronics. Tungsten oxide (WO3)-based materials are being explored for their utilization in solar cells, photo-electrochemical cells (PECs), electrochromic (EC) "smart windows," information displays, variable reflectance mirrors, and photo-detector materials. Designing ternary compounds or composite/hybrid structures coupled with tailoring the nano-architectures of WO3-based materials has been considered to be attractive develop potential candidates with enhanced performance. In this context, in this Thesis work, an attempt is made to prepare W-Mo-O nanocomposite films, which can be considered as …

Design And Development Of A Delivery System For Green Ionic Monopropellants And Testing Of A 22n Thruster, Jaclyn Mona Mejia

Open Access Theses & Dissertations

LMP-103S and AFM-315E are emerging propellants that are less toxic to the environment than the propellants currently being used in spacecraft propulsion. Both propellants are a blend of liquid fuel, oxidizer and a majority percent of water. The diluted solutions enable the capability to handle and store the propellants with fewer requirements; for this reason, it decreases the overall cost of the propellants since it needs less precautions. The Missile Defense Agency (MDA) awarded the University of Texas at El Paso (UTEP) a contract to further research green propellants and eventually replace Hydrazide.

Three Dimensional Finite Element Model For Residual Stresses In Parts Manufactured By Slm And Ebm, Jesus Gerardo Reyes Schuldes

Open Access Theses & Dissertations

Ongoing research efforts in industry and academia have a focus on optimal build parameters that lead to suitable mechanical properties with minimum defects in parts manufactured by powder bed fusion additive manufacturing technologies, such as Electron Beam Melting (EBM) and Selective Laser Melting (SLM). Additional and significant resources, including energy, time, and money are spent as a result of obligatory post-manufacturing heat and/or mechanical treatment to ensure optimum mechanical properties. One intrinsic fault in these technologies, which contributes to the need for treatment processes after part fabrication, is the creation of residual stresses during these processes. Residual stresses remain in …

The Former Asarco Demolition Fallout, A Post Study On Lead Soil Concentrations And Environmental Agents Of Redistribution In El Paso, Texas, Stephanie A. Robinson

Open Access Theses & Dissertations

The former El Paso ASARCO Smelting and Refining Co. operated between 1877 and 1999, the pyrometallurgic activity was estimated to have discharged excess of a 1,000 tons of lead (Pb) into the atmosphere from 1969-71. It was estimated 96 tons of (Pb) were emitted on an annual basis from the standing ore and fluid beds. The Environmental Protection Agency (EPA) determined that lead (Pb) is the heavy metal of the highest concentration within the vicinity of the smelter. After the smelter production ceased, flash flooding common to the southwest, such as the 2006 historic flood, increased transportation of superficial contaminants …

Raman Microscopic Analysis Of Internal Stress In Boron-Doped Diamond Thin Films, Emma M.A. Sundin

Open Access Theses & Dissertations

The correlations between induced stress on undoped and boron-doped diamond (BDD) thin films, sample chemical composition, and fabrication substrate are investigated in this study via confocal Raman microspectroscopic analysis. Stability of BDD films is relevant to fast-scan cyclic voltammetry, as film delamination and dislocation of BDD-coated electrodes that can occur during neurosurgical electrode implantation can negatively impact the biosensing reliability of this technique. Electrodes were fabricated by coating cylindrical tungsten rods using a custom-built chemical vapor deposition reactor. The results of the analysis reveal a direct correlation between regions of pure diamond and enhanced material stress, as well as preferential …

Material Behavior Of Window 7 Carrier Panel Tiles And Thermal Pane Fragments Recovered From The Space Shuttle Columbia, Brenda Roseanne Arellano

Open Access Theses & Dissertations

Since the end of the space shuttle program, a new generation spacecraft has been developed to transport humans back into space. NASAâ??s Orion will carry a crew beyond low-earth orbit and the exploration of Mars may be possible in the future. Space safety becomes significant with human spaceflight and the risks are high. However, aerospace materials may provide opportunities to prevent future disasters. When the space shuttle Columbia disintegrated during re-entry in 2001, thousands of debris were collected for analysis. In contrast, when the Challenger space shuttle broke apart in 1986, all shuttle debris were buried. These tragic disasters are …

Label-Free Raman Imaging To Monitor Breast Tumor Signatures, John Ciubuc

Open Access Theses & Dissertations

Methods built on Raman spectroscopy have shown major potential in describing and discriminating between malignant and benign specimens. Accurate, real-time medical diagnosis benefits in substantial improvements through this vibrational optical method. Not only is acquisition of data possible in milliseconds and analysis in minutes, Raman allows concurrent detection and monitoring of all biological components. Besides validating a significant Raman signature distinction between non-tumorigenic (MCF-10A) and tumorigenic (MCF-7) breast epithelial cells, this study reveals a label-free method to assess overexpression of epidermal growth factor receptors (EGFR) in tumor cells. EGFR overexpression sires Raman features associated with phosphorylated threonine and serine, and …

Image Data Mining For Quality Control Of Nanofiber Reinforced Piezoelectric Nanocomposites Based On Sem Images, Zhonghua Hu

Open Access Theses & Dissertations

Recently, portable and wireless nano-scaled devices have been widely used in environmental monitoring, medical implants, defense technology, industrial safety, and personal electronics, such as the nanowire-based gas and chemical sensors and programmable nanowire circuit for nano-processors. There has been an increasing demand for high energy density capacitors that can be engineered for various applications in advanced devices. In it, piezoelectric nanofiber materials play critical role in producing new products. A piezo-ceramic polymer composite contains a polymer of high dielectric strength and high permittivity ceramic inclusions, making it well suited as a high energy density capacitor. Furthermore, the research shows that …

Renewable Energy Systems Optimization Using Monte Carlo Simulation And Evolutionary Algorithms, Nicolas Lopez

Open Access Theses & Dissertations

This Dissertation explores the Renewable Energy Integration Problem, and proposes a Genetic Algorithm embedded with a Monte Carlo simulation to solve large instances of the problem that are impractical to solve via full enumeration. The Renewable Energy Integration Problem is defined as finding the optimum set of components to supply the electric demand to a hybrid

microgrid. The components considered are solar panels, wind turbines, diesel generators, electric batteries, connections to the power grid and converters, which can be inverters and/or rectifiers. The methodology developed is explained as well as the combinatorial formulation. In addition, 2 case studies of a …

Development And Integration Of The Janus Robotic Lander: A Liquid Oxygen - Liquid Methane Propulsion System Testbed, Raul Ponce

Open Access Theses & Dissertations

Initiatives have emerged with the goal of sending humans to other places in our solar system. New technologies are being developed that will allow for more efficient space systems to transport future astronauts. One of those technologies is the implementation of propulsion systems that use liquid oxygen and liquid methane (LO2-LCH4) as propellants.

The benefits of a LO2-LCH4 propulsion system are plenty. One of the main advantages is the possibility of manufacturing the propellants at the destination body. A space vehicle which relies solely on liquid oxygen and liquid methane for its main propulsion and reaction control engines is necessary …

Next Generation Exa-Scale Capable Software For High Fidelity Physics Aware Simulations, Ashesh Kumar Chattopadhyay

Open Access Theses & Dissertations

Physics aware simulations, often arising in problems of fluid dynamics, aerodynamics and multi-physics areas have demanded the need for computing software that has the capability to resolve the complexities at multiple scales to analyze and visualize the effects of their interactions with the surroundings. Usually the governing dynamics of these phenomenon appear in the form of complex partial differential equations whose numerical solutions impose various constraints on computational complexity, programming time and efficient throughput. In this scenario, the need of computing software that can solve very large problems resolving the physics of these phenomenon at multiple scales is imperative. Despite …

Ac Susceptibility And Epr Investigations Of Superspin Dynamics In Manganese Oxide Nanoparticles, Mahesh Koirala

Open Access Theses & Dissertations

We have investigated the superspin dynamics of 5 nm and 10 nm mixed state Mn3O4 nanoparticles utilizing ac-susceptibility and electron paramagnetic resonance measurements. The out of phase component of the ac-susceptibility measurements show a magnetic anomaly below (T

Design & Analysis Of A 500 Lbf Liquid Oxygen And Liquid Methane Rocket Engine, Daniel Eduardo Vargas

Open Access Theses & Dissertations

The rapid growth in demand for spacecraft technologies has spawned a need for a variety of new and innovative research. The utilization of liquid oxygen (LOX) and liquid methane (LCH4) in rocket engines have played an important role in space exploration efforts to promote missions to Mars with in-situ resource utilization for propellant production. This will allow the production of fuel needed to come back to Earth making the overall mission more cost effective by enabling larger usable mass.

The Center for Space Exploration and Technology Research has focused its efforts to developing Liquid Oxygen (LOX) and Liquid Methane (LCH4) …

The Design, Construction And Operation Of System To Analyze The Decomposition Gases Of Af-M315e, Jonathan Alejandro Valenzuela Brok

Open Access Theses & Dissertations

With the current trend of aerospace organizations towards developing green monopropellant, the key priority is to eliminate the use of highly dangerous monopropellants, such as hydrazine. In that vein, one of the best candidates to replace hydrazine is a monopropellant known as AF-M315E. AF-M315E was developed by the Air Force and is currently being advanced by NASA and private corporations for use on various satellite platforms, with NASA looking to launch a test satellites part of their Green Propellant Infusion Mission (GPIM), Raytheon providing support on the Missile Defense Agency's Network Centric Airborne Defense Element (NCADE) program and Department of …

Comprehensive Finite Element Modeling Of Ti-6al-4v Cellular Solids Fabricated By Electron Beam Melting, Edel Arrieta

Open Access Theses & Dissertations

Additive manufacturing permits the fabrication of cellular metals which are materials that can be highly customizable and possess multiple and extraordinary properties such as damage tolerance, metamorphic and auxetic behaviors, and high specific stiffness. This makes them the subject of interest for innovative applications. With interest in these materials for energy absorption applications, this work presents the development of nonlinear finite element models in commercial software platforms (MSC Patran/Nastran) that permit the analysis of the deformation mechanisms of these materials under compressive loads. In the development of these models, a detailed multiscale study on the different factors affecting the response …

Molecular Dynamics Studies Of Crystal Growth Phenomena In Cdte Based Heterostructures, Rodolfo Aguirre Ii

Open Access Theses & Dissertations

Cadmium telluride (CdTe) is a material used to make solar cells because it absorbs the sunlight very efficiently and converts it into electricity. However, CdTe modules suffer from degradation of 1% over a period of 1 year. Improvements on the efficiency and stability can be achieved by designing better materials at the atomic scale. Experimental techniques to study materials at the atomic scale, such as Atomic Probe Tomography (APT) and Transmission Electron Microscope (TEM) are expensive and time consuming. On the other hand, Molecular Dynamics (MD) offers an inexpensive and fast computer simulation technique to study the growth evolution of …

Redesign Of A Volume Adjustable Transtibial Prosthetic Socket, Samuel Terrazas Quezada

Open Access Theses & Dissertations

Recent research and development in prosthetics have aimed at improving socket designs and components to mimic more efficiently the human body. One such innovation is the Aperture Socket, a low-cost volume adjustable prosthetic socket. During the validation stage of its development, the Aperture Socket successfully demonstrated that it could compensate for volume changes, but various improvements on use and comfort were identified. This project develops and tests a redesign of the Aperture Socket previously developed for amputees in developing countries and subsequently patented and licensed to LIMBS International, Inc.

The first phase of this study was the creation of various …

Impact Of Reclaimed Asphalt Pavement And Recycled Asphalt Shingles On Laboratory And Field Performance Of Texas Asphalt Concrete Pavements, Berenice Salaices Gomez

Open Access Theses & Dissertations

The use of recycled materials in Asphalt Concrete (AC) mixes is highly promoted in the transportation industry. Recycled materials minimize the use of virgin materials, reduce the consumption of resources, and cut costs for new construction or rehabilitation projects. The incorporation of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in the AC mixture is promoted as long as equal or improved performance is achieved. The Texas Department of Transportation (TxDOT) is currently placing asphaltic concrete (AC) mixes that are lasting less than their expected performance life when recycled materials are used.

The objective of this Thesis is to …

Dft Study Of Adsorption Of Trimetallic Endohedral Fullerenes On Graphene, Nakul Nitin Karle

Open Access Theses & Dissertations

A density functional theory (DFT) study on the geometric and electronic structure of C60 and Sc3N@C80 along with their adsorption on pristine single layer graphene (SLG) is presented. C60 is found to adsorb in two nearly degenerate configurations: (i) with a pentagon facing the SLG, which is the most stable one, and (ii) with a hexagon facing the SLG in a face-to-face perfect alignment, rarely common in Ï?â??Ï? interactions, 0.06 eV higher in energy. The calculated binding energy of 0.76 eV, which includes dispersion effects, is in good agreement with previous theoretical and experimental reports. On the contrary, Sc3N@C80 adsorption …

An In-Depth Evaluation Of Shear Box Compactor For Hot Mix Asphalt, Isaac Jaime Aguilar

Open Access Theses & Dissertations

Asphalt pavement is present in each roadway in every town or city today and it is paramount to properly design pavement to efficiently reduce its deterioration. To determine how pavement fails, pavement specimens prepared in the laboratory undergo performance tests which demonstrate the pavements strength and durability. Performance tests require little variability from compacted specimens, and it is critical to have a compaction method which is similar to field compaction and produces homogenous specimens. Currently, laboratory performance test specimens are obtained with the Superpave Gyratory Compactor (SGC). That device has few similarities to the rolling compactor, which performs the actual …

Structural And Mechanical Characterization Of Nanocrystalline Tungsten And Tungsten-Based Alloy Thin Films For Extreme Environment Applications, Gustavo Martinez

Open Access Theses & Dissertations

Extreme environments associated with nuclear applications often results in degradation of the physical, mechanical and thermo-mechanical properties of the materials. Tungsten (W) exhibits unique physical and mechanical properties, which makes tungsten a good candidate for nuclear applications; however, intrinsic W exhibits low fracture toughness at all temperatures in addition to a high ductile to brittle transition. In the present work, nanocrystalline W, W-Y and W-Mo alloys were nanoengineered for nuclear applications. Nanocrystalline tungsten coatings with a thickness of ~1 µm were deposited onto Silicon (100) and Sapphire (C-plane) using RF and DC sputtering techniques under various growth conditions. Yttrium content …

Optimization Of Collagen Microneedle Using Taguchi Method, Abhilash Aditya

Open Access Theses & Dissertations

Research is conducted to create dissolving collagen microneedles and to optimize the parameters for close to perfect dimension microneedles. A collagen microneedle patch has been developed with a micro-manufacturing process (micro-molding process). The collagen microneedles, varying in length from 300 to 600-μm may reach different targeted layers of the skin depending on the application. As the microneedles penetrate the skin they dissolve, delivering collagen through the epidermis. Such addition of collagen directly to the dermis layers allows it to be absorbed, increasing skin's strength and resilience, since it is one of the natural components of the younger looking skin. This …

Characterization Of Electrically Conductive Inks In Simulated Space Environment, Kazi Md Masum Billah

Open Access Theses & Dissertations

Increasing numbers of satellite missions necessitate a standalone power supply with self-recovery capabilities in case of failure in the space environment. A self-repairing kit was developed with the capabilities to repair the damaged solar array by dispensing conductive inks. Dispensing of conductive materials using direct writing technology to the space environment not only repairs damaged electronic components but also demonstrates the possibilities of manufacturing in outer space. For earth application, properties of direct writing inks have been evolved. In space application, direct writing inks or conductive inks have some issues such as outgassing, vapor pressure, curing etc.Therefore, having the properties …

Process Development And Characterization Of Smart Parts Fabricated Using Powder Bed Fusion Additive Manufacturing Technologies, Mohammad Shojib Hossain

Open Access Theses & Dissertations

The fields of modern energy conversion, e.g., fossil fuel, natural gas, and coal power plants, are in increased need of health monitoring and data collection (temperature, pressure, and flow rate) to improve process efficiency and satisfy the demand for clean energy. In situ process monitoring can lead to a robust automated system to achieve the goal. The monitoring equipment or sensors in energy systems components (e.g., pressure tube, turbine blade, and fuel injector) undergo high temperature, high pressure, and corrosive environments; for example, combustion inlet conditions can reach up to 810 K and 2760 kPa [1]. Therefore, a reliable, accurate, …