Physical Sciences and Mathematics Commons^™

Computational Methods For Prediction And Classification Of G Protein-Coupled Receptors, Khodeza Begum

Open Access Theses & Dissertations

G protein-coupled receptors (GPCRs) constitute the largest group of membrane receptor proteins in eukaryotes. Due to their significant roles in many physiological processes such as vision, smell, and inflammation, GPCRs are the targets of many prescribed drugs. However, the functional and structural diversity of GPCRs has kept their prediction and classification based on amino acid sequence data as a challenging bioinformatics problem. As existing computational methods to predict and classify GPCRs are focused on mammalian (mostly human) data, the ultimate goal of our project is to establish an ensemble approach and implement a web-based software that can be used reliably …

Estimating The Coefficients Of A Linear Differential Operator, Maria Ivette Barraza

Open Access Theses & Dissertations

Principal Differential Analysis (PDA; Ramsay, 1996) is used to obtain low dimensional representations of functional data, where each observation is represented as a curve. PDA seeks to identify a Linear Differential Operator (LDO) L = ω0I + ω 1D + ... + ωmDm, where I denotes the identity function and D j the jth derivative, that satisfies as closely as possible that Lx = 0 for each functional observation x. A theorem from analysis establishes that the coefficients of the LDO are in the Sobolev space, and thus can be approximated by B-splines. Current PDA software used to estimate the …

Synthesis Of New Fullerene Derivatives For Photovoltaic And Biological Applications, Edison Castro

Open Access Theses & Dissertations

Functionalized fullerenes exhibit improved solubility and different chemical and physical properties that allow applications in multiple fields such as photovoltaic and biological applications. Currently, perovskite solar cells (PSCs) are the most rapidly developing type of solar cells with certified efficiencies rising from 3.8% in 2009 to 22.1% in 2016. The good electron transporting and solution processable properties of most fullerene derivatives make them the most popular electron transporting materials (ETMs) in inverted perovskite solar cells (PSCs).

The work is reported in 11 chapters. We start with a fullerene overview followed by cleaver and elegant methodologies that allow the synThesis of …

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

Open Access Theses & Dissertations

N/A

A Study Of Hippocampal Microglia Distribution In Pre-Adolescent Mice Chronically Exposed To Lead, Salvador Dominguez

Open Access Theses & Dissertations

Background: Lead is a major unresolved child health hazard. Children are uniquely vulnerable to the effects of lead exposure, which include disruption of brain development and brain function. How lead exposure alters brain development and brain function is not currently known. Our laboratory has been developing a mouse model to understand effects of low-level lead exposure in the developing brain. In previous studies, we have shown that early chronic low level lead exposure diminished the number of microglia in the dentate gyrus region of the hippocampus, an area responsible for learning and memory. Building on the results of the previous …

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.

Study Of Electron Gas On A Neutron-Rich Nuclear Pasta, Enrique Ramirez-Homs

Open Access Theses & Dissertations

This study used a classical molecular dynamics model to observe the role of electron gas on the formation of nuclear structures at subsaturation densities (Ï?<0.015 fm^-3) and low temperatures (T< 1MeV ). The simulations were performed by varying the Coulomb interaction strength on systems of isospin symmetric and asymmetric matter with periodic boundary conditions. The effect was quantified on the fragment size multiplicity, the inter-particle distance, the isospin content of the clusters, the nucleon mobility and cluster persistence, and on the nuclear structure shapes. The existence of the nuclear pasta structures was observed even with the absence of the Coulomb interaction but with a modication of the shapes formed. It was found that the presence of the electron gas tends to distribute matter more evenly, forms less compact objects, decreases the isospin content of clusters, modies the nucleon mobility, reduces the persistence and the fragment size multiplicity, but does not alter the inter-particle distance in clusters. The degree of these effects also varied on the nuclear structures and depended on their isospin content, temperature, and density.

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 …

Evaluation Of A Roller Method For Geochemical Leach Testing, Troy Allen Svede

Open Access Theses & Dissertations

Currently, multiple tests are being used when evaluating an MSE wall backfill material for pH, conductivity, chloride concentration, and sulfate concentration. There is no one test to measure all four characteristics when testing a soil. Texas Department of Transportation (TxDOT) uses four different tests to measure these characteristics. The goal of this research was to refine a simplified test procedure that was created by David Borrok et al., the Tex-620-M. The method that was developed to replace the current TxDOT test procedures Tex-620-J, Tex-128-E, and Tex-145-E test procedures is the Tex-620-M2. Leaching kinetics were analyzed for gravel and fines by …

Active Learning Effect On The Public's Perception Of Anthropogenic Global Climate Change, Ivy Gisselle Trevizo

Open Access Theses & Dissertations

Anthropogenic, or human-caused global climate change has been debated for many years among the public despite the growing evidence that there is scientific consensus on this topic. A gap has been discovered between scientific evidence of increasing temperatures and the public's perception on climate change. This gap has been hypothesized to come from the method in which the scientific community represents scientific evidence. The goal of this study was to determine if active learning techniques around local and regional climate change and climate change impacts changes the awareness, perception, and behavioral intentions of different segments of the public. The study …

Spectroscopic Analysis Of Neurotransmitters: A Theoretical And Experimental Raman Study, Matthew Alonzo

Open Access Theses & Dissertations

Surface-enhanced Raman spectroscopy (SERS) was applied to investigate the feasibility in the detection and monitoring of the dopamine (DA) neurotransmitter adsorbed onto silver nanoparticles (Ag NPs) at 10-11 molar, a concentration far below physiological levels. In addition, density functional theory (DFT) calculations were obtained with the Gaussian-09 analytical suite software to generate the theoretical molecular configuration of DA in its neutral, cationic, anionic, and dopaminequinone states for the conversion of computer-simulated Raman spectra. Comparison of theoretical and experimental results show good agreement and imply the presence of dopamine in all of its molecular forms in the experimental setting. The dominant …

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 …

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 …

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

A New Method For Ultra-Low Sulfate Extraction And A Pilot Study In Arid Soils, Marisela Montelongo

Open Access Theses & Dissertations

Sulfur in soils is a crucial nutrient for all organisms including plants. Sulfate (SO42-), a water soluable anion, is a good source of this important element. Because of the importance of sulfur for agriculture, the use of sulfate has been well studied in temperate climate zones, and it is generally accepted that microbes play a critical role in controlling the availability of sulfate. Organically bound sulfur, such as sulfate esters and carbon-bonded sulfur, compounds that are generated and decomposed by microbes, are essential sulfur sources for plants under these conditions. For arid environments, knowledge of sulfate turnover in soils by …

Synthesis And Post-Synthetic Transmetalations Of Metal-Organic Frameworks Containing Bimetallic Centers, Jose Miguel Veleta

Open Access Theses & Dissertations

The heterobimetallic metal-organic frameworks (MOFs) of the type HKUST-1 were obtained through post synthetic cation exchange processes, where Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylate) was exposed to solutions of Mn2+, Fe2+, Co2+, or Ni2+ at time intervals of 6, 12, 24, 36, 48, and 72 hours. The elemental composition of the products was analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES), showing partial substitution of copper ions in the frameworks. Transmetalations done with Mn2+ and Ni2+ show a relatively low cation exchanged through the different time intervals, with maximum transmetalation percentages of 2.4 % for Mn2+ and 2 % for Ni2+ …

Exposure Of Commercial Titanium Dioxide And Copper Hydroxide Nanomaterials On Basil (Ocimum Basilicum): A Life Cycle And Transgenerational Study, Wenjuan Tan

Open Access Theses & Dissertations

Although thousands of reports have shown that engineered nanomaterials (ENMs) can alter several agronomical, physiological, and biochemical parameters in plant and mammal systems, the effects of long-term exposure and varietal responses are scarce. Titanium dioxide nanoparticles (nano-TiO2) and copper hydroxide nanoparticles [nano-Cu(OH)2], which are widely used in agriculture, medicine, food industry, textile, among other areas, are among the ENMs with high production and consumption globally. Though reports indicate that these ENMs affected plant development and metabolism, their interactions with basil (Ocimum basilicum) are unknown. Basil is a popular culinary herb worldwide, featured in Asian and European cuisine and has more …

Bimetallic Centers With Open Coordination Sites And Magnetic Nanocomposites For Water Remediation, Karen Ventura

Open Access Theses & Dissertations

The development of effective, renewable and environmentally friendly energy sources is essential to supply the growing global energy demands. The use of fossil fuels to fulfill those energy demands have led to the increase of greenhouse gases and water contamination. The extraction of oil and gas requires a large amount of pressurized water, resulting in contaminated water as a byproduct. Meanwhile, ensuring access to clean water is one of the greatest global challenges of this century.

The following study is presented in three sections. In the first section, a bimetallic system with open coordination sites that can be used as …

Essays On Sofwtare Development Projects: Impact Of Social And Technological Factors On Project Performance And Co-Diffusion Of Software Sourcing Arrangements, Niharika Dayyala

Open Access Theses & Dissertations

Software development is a complicated process which is accomplished by the combined effort of the key elements such as people, processes, and technology. Software development firms are on a constant quest to identify the best practices for managing the key elements to improve their software development project outcomes and to deliver successful software projects. This Dissertation aims to study key elements that can influence the software development project performance through three distinctive studies. The first essay of this Dissertation investigates the impact of people factors on software project outcomes. Specifically, it examines the impact of team characteristics on the software …

Neutrino Oscillations And The Reno Experiment, Karla Rosita Tellez Giron Flores

Open Access Theses & Dissertations

Neutrinos are the second most common particles in the universe, after the photons. Neutrinos (and antineutrinos) exist in three different "flavors", namely, electron, tau and muon neutrinos. A physical neutrino, however, can oscillate among these three flavors and, thus, it is said to be a mix of the three flavor states. In quantum mechanics representation, it is said that the three flavor states are the mixture of the three mass states. This mixture of neutrinos can generally be parameterized by the three so-called mixing angles (&thetas;12, &thetas;23, &thetas;13), three squared mass differences Δmij 2, i, j = 1, 2, 3 …

Design And Regioselective Synthesis Of Fullerene Derivatives For Metal-Organic Hybrid Architectures, Catalina Suarez

Open Access Theses & Dissertations

In the last years different fullerene derivatives and endohedral fullerenes have been reported and their potential applications as electronic, magnetic, catalytic, biological and optical materials have been explored. In this work we describe the characterization of new endohedral fullerenes; the exohedral functionalization of fullerenes with organic addends or metal clusters and their application in metal-organic hybrid architectures.

We synthesized fullerene polymers with a variety of staircase linear architectures, zigzag polymers and a perfectly linear polymer using an hexakis-fullerene adduct with two 4,5-diazafluorene groups located at trans-1 positions, using Hg, Cd, Zn and33 Cu as the metal centers. Our results showed …

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 …

Self-Interaction Corrected Polarizabilities Of Small Molecules, Sharmin Akter

Open Access Theses & Dissertations

Density Functional Theory (DFT) is one of the most successful and popular computational Quantum Mechanical approaches to understand materials. DFT allows the prediction of material properties from the electron density. Although in principle density functional theory is exact, it, however, relies on approximate functional for exchange-correlation energy. Due to the approximate nature of the exchange-correlation functional, the self-Coulomb energy of the electrons is not exactly canceled out by the self-exchange leading the spurious self-interaction error (SIE). This error is responsible for the unphysical orbital energies of DFT and delocalization of the orbitals. The orbital energies of the valence electrons are …

Tracing Anthropogenic Salinity Inputs To The Semi-Arid Rio Grande River: A Multi-Isotope Tracer Approach, Sandra Garcia

Open Access Theses & Dissertations

Water is an important component for life and as such water quality and availability are major concerns in the world today. In arid to semi-arid regions, freshwater quality is especially important due to its scarcity. Elevated salinity of rivers in arid regions poses potentially devastating consequences for the communities that depend on these rivers as a source of freshwater. In the Rio Grande region, high salinity has led to severe reductions in crop productivity and accumulation of salts in soils. Salinity inputs into the river may come from both anthropogenic and natural sources. Thus, identifying and quantifying salinity inputs to …

Integration Of Heterogeneous Traffic Data To Address Mobility Challenges In The City Of El Paso, Daniel Michael Mejia

Open Access Theses & Dissertations

Transportation performance measures are defined as quantitative and qualitative indicators that rely on data or information to explain mobility, traffic congestion, safety, environmental sustainability and other factors. Although performance measures have been used for freeways and other highways, not many have been specified and applied to the freight transportation system. Under the Fixing America's Surface Transportation Act (FAST Act), state transportation agencies and metropolitan planning organizations in the United States are implementing freight performance measurement systems for performance assessment. This research aims to expand the existing limited freight performance measures and organize them into a comprehensive framework that can be …

Classification Of Radar Jammer Fm Signals Using A Neural Network Approach, Ariadna Estefania Mendoza

Open Access Theses & Dissertations

A Neural Network (NN) used to classify radar signals is proposed for the purpose of military survivability and lethality analysis. The goal of the NN is to correctly differentiate Frequency-Modulated (FM) signals from Additive White Gaussian Noise (AWGN) using limited signal pre-processing. The FM signals used to test the NN approach are the linear or chirp FM and the power-law FM. Preliminary simulations using the moments of the signals in the time and frequency domain yielded better results in the frequency domain, suggesting that time domain training would not be as effective frequency domain training. To test this hypoThesis, we …

Deep Learning Method Vs. Hand-Crafted Features For Lung Cancer Diagnosis And Breast Cancer Risk Analysis, Wenqing Sun

Open Access Theses & Dissertations

Breast cancer and lung cancer are two major leading causes of cancer deaths, and researchers have been developing computer aided diagnosis (CAD) system to automatically diagnose them for decades. In recent studies, we found that the techniques in CAD system can also be used for breast cancer risk analysis, like feature design and machine learning. Also we noticed that with the development of deep learning methods, the performance of CAD system can be improved by using computer automatically generated features. To explore these possibilities, we conducted a series of studies: the first two studies focused on transferring the original CAD …

Developing A System Dynamics Model Of The El Paso Water Resources System, Majid Alahmoradi

Open Access Theses & Dissertations

The city of El Paso is growing rapidly, increasing water demand in a water-scarce region. In this research system dynamics modeling is applied to simulate dynamic behavior of the El Paso water resources system in order to investigate the city's portfolio based upon a supply-demand side and demand side management approach. System Dynamic simulation involves several steps, including system conceptualization, data collection, simulation model development, and model verification and sensitivity analysis. A high-level conceptualization of the El Paso water resources system is presented, including withdrawal sources, water and wastewater treatment facilities, water demands, and flow linkages are will be presented. …

Complementary Charged Molecular Imprints Of West Nile Virus Antibodies, Julio Rincon

Open Access Theses & Dissertations

There is a significant demand for robust and stable receptor molecules that can mimic biological molecules, such as antibodies. Relying only on natural recognition molecules have greatly limited the uses and capabilities of many aspects of health sciences due to product expense and stability. This is especially important in medically underserved areas where the lack of resources and faulty or limited cold-chain makes antibody based diagnostics very difficult to implement.

With molecular imprinting, it is possible to recognize diseases with the added advantage of product stability, long term use, fast preparation and ease of scalability, all while being cost effective. …