Physical Sciences and Mathematics Commons^™

Computational Study Of Grain Structure Evolution In Cdte/Cds Via Molecular Dynamics, Sharmin Abdullah

Open Access Theses & Dissertations

Grain structure analysis plays an important role in the identification of grain boundary characteristics, which can affect the efficiency of Cadmium Telluride/Cadmium Sulfide (CdTe/CdS) solar cells since they can act as recombination centers for carriers. Computer simulations such as molecular dynamics (MD) can be a very convenient and cost- effective method of investigating the growth evolution and grain structure of materials. The recently reported and experimentally validated MD simulated growth of polycrystalline CdTe/CdS films shows that these materials mostly consist of zinc blende (ZB) and wurtzite (WZ) structures, along with highly disordered atoms. However, little information about the semiconductor compound …

Rational Design Of Multifunctional Nanocatalysts For Environmental Remediation And Energy Conversion Technologies, Md Ariful Ahsan

Open Access Theses & Dissertations

The discovery of efficient and sustainable carbon-based nanotechnologies to solve both the scarcity of drinking water and global energy crisis has become a paramount task in the last decades. Owed to the fast population growth and industrialization of the modern society, access to potable water and clean energy technologies is becoming very hard around the globe. Water pollutants have become a serious threat to the environment and ecology because of their toxic nature. Parallelly, the current hydrocarbon-based fuel industries are generating high levels of contamination across the planet, making imperative the development of cleaner energy technologies. In this regard, the …

Linking Plot And Landscape Level Phenology, Alejandra Flores

Open Access Theses & Dissertations

Plant phenology has become popularize since the 1990s to help understand the effects of climate change on vegetation, it is a way to study the patterns of leaf-out, flowering, and senescing of the life-cycle of the plant. The timing from start of season (SOS) to end-of-season (EOS) of plant leaf-out development has important implication on ecosystem productivity and carbon cycling across ecological scales from individual trees to whole regions. The need for plant phenology studies in dryland are highly anticipated, since they make up 40% of the terrestrial landscape and recently have shown the play an important role in the …

Geophysical Studies Of The Characteristics Of Fluvial And Desert Soils In Rio Grande Valley Of West Texas And Southern New Mexico, Aimee V. Garcia

Open Access Theses & Dissertations

Agriculture in arid lands, such as in the Rio Grande Valley in west Texas, relies on flood irrigation. However, flood irrigation can cause salt buildup and greenhouse gas emissions associated with pedogenic carbonate precipitation. The ability of irrigation to promote crop growth is influenced by geochemical and hydrological processes controlled, in part, by soil grain size, larger-scale soil structure, and mineralogy. This study investigated soils from 3 regions 1) A pecan orchard in the river valley of Tornillo, TX, with soil derived from fluvial deposits, undergoing flood irrigation every 2 to 3 weeks in spring through fall, 2) The El …

Goes-16 Level 2 Land Surface Temperature Product-Filling For Cloud Masked Data, Guadalupe Ortega

Open Access Theses & Dissertations

The GOES-16 satellite ground segment team develops different levels of environmental products and makes them readily available to the public. The level 2 Land Surface Temperature (LST) product aims to provide a remote measurement of the Earth’s surface temperature every hour. LST is of fundamental importance to many aspects of the geosciences, for example, to study the Urban Heat Islands (UHI) effect. The product however, does not provide values for pixels where the satellite imager’s view is obstructed by clouds, as determined by a cloud mask intermediate product. The objective of this thesis is to estimate LST in the cloud …

Demystifying The Practices Of Software Design And The Impact On Codebase Quality And Sustainability, Khandoker Rahad

Open Access Theses & Dissertations

Software systems continue to increase in size and complexity to match the ever-increasing user expectations. Designing and engineering such complex software systems brings about unique challenges. Complex systems are not only expensive to develop, but even more expensive to maintain. Most software systems must adapt to continuously changing business contexts and requirements. In the process, software accumulates arbitrary complexities making its maintenance even more challenging. Design and modeling are the primary methodologies to develop reliable, sustainable, maintainable systems. The development of novel design languages, tools, and methodologies is frequently not able to keep up with the exponential increase in software …

8th Position Bodipy Chemistry, Laura I. Saucedo

Open Access Theses & Dissertations

The projects examined in this dissertation demonstrate how the meso substituents N and S lone pair-BODIPY core interaction influence the chemistry and properties of BODIPY fluorophores. Three objectives were completed experimentally and computationally. In the first project the meso amide substituent delocalizes the nitrogen lone pair into the carbonyl, preventing a hemicyanine resonance that causes blue emission in 8-amino-BODIPYs. The second and third projects substituting aniline or phenylthiol derivatives onto the 8th position, respectively. The aniline and phenylthio lone pair interaction with the BODIPY core can be modulated by electron-donating (ED) or –withdrawing (EW) moieties placed para on the aryl …

A New Algorithm For Robust Affine-Invariant Clustering, Andrews Tawiah Anum

Open Access Theses & Dissertations

Cluster analysis is an unsupervised machine learning technique commonly employed to partition a dataset into distinct categories referred to as clusters. The k-means algorithm is a prominent distance-based clustering method. Despite its overwhelming popularity, the algorithm is not invariant under non-singular linear transformations and is not robust, i.e., can be unduly influenced by outliers. To address these deficiencies, we propose an alternative clustering procedure based on minimizing a “trimmed” variant of the negative log-likelihood function. We develop a “concentration step”, vaguely reminiscent of the classical Lloyd’s algorithm, that can iteratively reduce the objective function. Multiple real and synthetic datasets are …

The Physiological Factors Of Diabetes And Their Effect On The Cognitive And Emotional Functioning In Older Populations: A Secondary Data Analysis, Celeste Anahi Alvidrez

Open Access Theses & Dissertations

Background: The rates of Type 2 Diabetes (T2D) have increased over the past 20 years in all age groups. The physiological factors that underlie T2D could have impact on specific brain pathways that support cognitive and emotional functioning. Aims and Objective: The goal of this study was to examine whether older Mexican American individuals with a history of T2D were more likely to develop later cognitive impairment and/or depression. Hypotheses: It was predicted that elderly participants (mean age at time of interview = 87.87 years) with a history of T2D onset prior to age 65, are more likely to have …

Interval Estimates: How To Make Them More Adequate And How To Use Them In Economic Analysis And Decision Making, Laura Adriana Berrout-Ramos

Open Access Theses & Dissertations

In many real-life situations, we need to make decisions in situations when we do not have full information about the consequences of different decisions. In particular, instead of the exact values of the relevant quantities, we only know lower and upper bounds on these values – i.e., we know an interval that contains the actual (unknown) value. These interval estimates often come from experts. This fact naturally leads to the following important questions: How should we make decisions under such interval uncertainty? How to gauge the quality of the resulting decisions? And if this quality is not sufficient – because …

Land Use And Land Cover Change Impact On Sustainability In The United Arab Emirates: A Big-Data Approach Using Google Earth Engine, Wissam Atwah

Open Access Theses & Dissertations

The relevance of land use and land cover change (LULCC) impact on sustainability and well-being is increasing due to the urban growth challenges. LULCC data offers significant insight into the historic development patterns and their relations to various sustainability indicators. Different from the previous LULCC studies that merely focused on investigating LULCC problems in a small area (e.g., a city of an urban area) within a short span of time (e.g., a year), the current study intends to assess the long-term urbanization trend within a 20-year period for a whole country through the tracking of LULCC changes within the period. …

Effects Of Coated/Uncoated Copper-Based Nanoparticles And Compounds On Rice (Oryza Sativa) And Soybean (Glycine Max) Plants, Chaoyi Deng

Open Access Theses & Dissertations

Engineering nanoparticles (ENPs) have been widely used in industry due to their promising chemical, physical, electrical, magnetic, optical, and electronic properties. Copper-based ENPs are used as gas sensors, catalysts, semiconductors and agricultural products, among others. Because of their antifungal and antibacterial properties, they are used in agriculture as insecticides, herbicides and antifungal agents. Due to their mass production and use, ENPs are likely to be ubiquitous in our in the environment in the near future. In addition, metal nanoparticles are usually coated with organic compounds to enhance the properties of the nanoparticles. Previous studies have shown that copper-based ENPs can …

Global Analysis Of The Hydrologic Sensitivity To Climate Variability, Marisol Dominguez

Open Access Theses & Dissertations

Identifying the regions with greatest changes in their hydrologic behavior under extreme weather events in the 21st century, constitutes a study priority of global impact. Here, we present a global assessment assessing the sensitivity of the world’s water landscapes to climate variability during 2001-2016, using a new metric called the Hydrologic Sensitivity Index (HSi). This equation is based on the well-known Budyko curve that uses annual values of Potential and Actual Evapotranspiration (PET and AET), and Precipitation (P), to assess the hydrologic behavior of a location under a given climatic condition by plotting the Evaporative Index (AET/P) against the Dryness …

Reconstructing The Transition From Laramide Contraction To Rio Grande Rift Extension, Aaron Conley

Open Access Theses & Dissertations

Exposure of tilted Eocene-Oligocene volcanic and sedimentary units unconformably overlying folded and thrusted Mesozoic rocks in the southern Indio Mountains provide an important geologic record of the transition from Laramide contraction to Rio Grande rift extension. Detailed geologic mapping and cross-section reconstruction combined with sedimentary analysis and geo/thermochronologic methods are used to test the hypothesis that Laramide contractional structures and post-Laramide topography focused ignimbrite and sedimentary deposition within two paleovalleys located in the northwest and northeast portions of the study area. Laramide deformation in the study area is confined to Mesozoic units and includes a series of low-angle thrust faults …

Synthesis, Characterization, And Direct-Ink-Writing Of Syntactic Foams, Andrea Irigoyen

Open Access Theses & Dissertations

This project encompasses three different methods to fabricate syntactic foams using a PDMS matrix i.e., hollow spheres inclusion, pore generator leaching by solvent, and emulsion. The foam formation by using polysiloxane hollow spheres is done in a 3-step process. The first step is to create a core of polystyrene following a dispersion polymerization process. The goal for the size of the pore is to monodisperse and have an average diameter of 5-10 μm, so the polystyrene core must be as well within that range. After that, the cores are coated with a polysiloxane shell by following a polymerization by condensation …

Impact Of Xenobiotics On Neuronal Outcomes, Gabriela Henriquez

Open Access Theses & Dissertations

Neurodegenerative diseases are a common affliction of the Central Nervous System. They are caused by age, genetics, and environmental factors. Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic Lateral Sclerosis are well-known among the host of neurodegenerative disorders, with Alzheimer's disease and Parkinson's disease being the leading pathologies across this canvas. It is known that the pathogenesis of neurodegenerative diseases is multifactorial due to the involvement of genetic mutations, radical-induced protein damage, abnormal aggregation of misfolded proteins, and the formation of amyloid deposits. The amyloid proteins in neurodegenerative disease include Tau and Amyloid (Aβ) in Alzheimer's disease and α-Synuclein in …

Environmental Justice Issues And Sea Level Rise In Frontline Communties Along The Gulf Coast, Karla Michel Lopez

Open Access Theses & Dissertations

Sea level rise poses a great threat to coastal areas and our way of life. As flooding increases in frequency and intensity across the country, vulnerable populations become a target to its impacts. The U.S. dedicates much research to risk communication and climate change adaptation strategies; however, these coastal areas are home to a large percentage of underserved and underrepresented communities that can be challenging to meaningfully engage. The impacts of short-term sea level rise combined with long-term sea level rise will not only cause flooding, erosion, and intrusion of saltwater into freshwater resources but also increased financial consequences, such …

Combination Of Nir Triggered Lanthanide Upconverting Nanoplatforms With Fullerene For Controlled Drug Release And Photo Cancer Therapy, Lei Ma

Open Access Theses & Dissertations

Photodynamic therapy (PDT) is an emerging, externally activatable, treatment modality for various diseases, especially for cancer therapy. Similar to radiotherapy, the mode of action with PDT involves the use of electromagnetic radiation to generate radical species in situ. However, PDT is a much milder approach for cancer treatment. Because of the unique physicochemical properties of fullerenes (such as C60), many potential biomedical applications, including PDT, became possible with them. As a main principle of PDT, the anticancer properties of various fullerene preparations usually result from their ability to generate cytotoxic reactive oxygen species (ROS), after photoexcitation. However, because of the …

Structural And Stratigraphic History Of A Deformed Diapir Margin, Onion Creek Salt Diapir, Paradox Basin, Utah, David Lankford-Bravo

Open Access Theses & Dissertations

The Onion Creek Salt Diapir (OCSD) located in the northern Paradox Basin in Utah is a 0.6 km wide X 3.6 km long X 1.6 km tall salt diapir surrounded by variably deformed Paleozoic through Cenozoic strata. The area is a classic area for the study of deformation around salt diapirs. This study uses high-resolution GPS-enabled-tablet and 3D photogrammetric outcrop model-based field mapping, section measuring, thin section petrography, structural restorations, and newly developed 3D modelling workflows to document the styles, timing, nature, and distribution of deformation in strata surrounding the OCSD. Permian Cutler Group sediments on the northern margin of …

Study Of Barrier Heights And Magnetic Property Using Locally Scaled And Perdew-Zunger Self-Interaction Methods, Prakash Mishra

Open Access Theses & Dissertations

Kohn-Sham density functional theory is a widely used method to estimate the ground state total energies and densities of interacting correlated electronic structures of atoms, molecules, clusters, solids, and liquids. In theory, exact solutions for these properties can be obtained by solving self-consistent one-electron Schrodinger equations based on density functionals for the energy.The practical application of KS DFT require approximation to the exchange-correlation energy functional. Many density functional approximations (DFAs) have been developed with various degree of sophistication and complexity by the satisfaction of exact constraints. Depending on the complexity, these functionals include electron density, density gradients, density Laplacian, kinetic …

Identification And Evaluation Of Critical Transportation Infrastructure Resilience After Hydro-Meteorological Event, Herman Serrato

Open Access Theses & Dissertations

Modern civilization is dependent on essential infrastructure assets that allow society to function in today’s standards. Critical interdependent infrastructure such as transportation, communication, security, and public health are marvels of human innovation and an important aspect of civilization's evolution. Recent world events such as climate change have underlined the necessity to develop strategic plans to enhance the resilience of infrastructure. This study aimed to identify and evaluate the flooding potential of critical transportation infrastructure that will influence traffic flow and impact the economy. The technical workflow is based on observations, predictions, experiments, testing, and analysis to derive a resilience score …

Transboundary Air Quality Governance: A Case Study Of The Paso Del Norte Air Basin 1940-2000, Laura Margarita Uribarri

Open Access Theses & Dissertations

For thousands of years, the Paso del Norte region which today includes Ciudad Juárez, Chihuahua, El Paso, Texas, and Sunland Park, New Mexico, has been a strategic location by virtue of its geographic positioning at the lowest and easiest passage across the continental divide. During the 19th and 20th centuries as railroad networks connected the region to the far reaches of the U.S. and the interior of Mexico, it became a nexus for natural resource and labor extraction. Mining and smelting industries were later joined by agriculture and manufacturing to benefit from the transportation network and the abundance of labor. …

Measurement Of Radon Gas At Kilbourne Hole, Michel Eduardo Luna Lucero

Open Access Theses & Dissertations

Several radon studies have reported a possible correlation of the gas emanation with faults and seismic activity in the area, but few studies have been conducted in seismically inactive areas. Features such as the Kilbourne Hole in New Mexico, a maar volcano formed by an interaction between magma and water, can reveal important information about connection between radon concentration levels and structural geology.

The purpose of this thesis is to determine the radon concentration levels in and around the crater of the Kilbourne Hole. The results are compared with geological, gravity and magnetic surveys to have a better understanding of …

A Integrated Approach Of Deep Learning And Augmented Reality For Pneumonia Detection In Chest X-Ray Images, Jeevarathinam Senthilkumar

Open Access Theses & Dissertations

Pneumonia is a viral or fungal illness that spreads to the lungs of the human body, causing fluid to accumulate in the lungs' air sacs. Millions of people are affected by this disease each year. One of the most common radiological diagnostics for diagnosing and screening this kind of sickness is a chest X-ray. The most commonly available radiological test for diagnosing and screening this kind of illness is a chest X-ray. An inaccurate diagnosis, especially over-diagnosis and under-diagnosis, is a common issue in the medical sector. As another issue, human-assisted diagnosis has limitations like the availability of an expert, …

Why Moments (And Generalized Moments) Are Used In Statistics And Why Expected Utility Is Used In Decision Making: A Possible Explanation, R. Noah Padilla, Vladik Kreinovich

Departmental Technical Reports (CS)

Among the most efficient characteristics of a probability distribution are its moments and, more generally, generalized moments. One of the most adequate numerical characteristics describing human behavior is expected utility. In both cases, the corresponding characteristic is the sum of results of applying appropriate nonlinear functions applied to individual inputs. In this paper, we provide a possible theoretical explanation of why such functions are efficient.

How Multi-View Techniques Can Help In Processing Uncertainty, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Multi-view techniques help us reconstruct a 3-D object and its properties from its 2-D (or even 1-D) projections. It turns out that similar techniques can be used in processing uncertainty -- where many problems can reduced to a similar task of reconstructing properties of a multi-D object from its 1-D projections. In this chapter, we provide an overview of these techniques.

Why Do People Become Addicted: Towards A Theoretical Explanation For Eyal's Experiment-Based Hook Model, Christopher Reyes, Vladik Kreinovich

Departmental Technical Reports (CS)

Why do people become addicted, e.g., to gambling? Experiments have shown that simple lotteries, in which we can win a small prize with a certain probability, and not addictive. However, if we add a second possibility -- of having a large prize with a small probability -- the lottery becomes highly addictive to many participants. In this paper, we provide a possible theoretical explanation for this empirical phenomenon.

Why Ovals In Eliciting Intervals?, Joshua Zamora, Vladik Kreinovich

Departmental Technical Reports (CS)

To elicit people's opinions, we usually ask them to mark their degree of satisfaction on a scale -- e.g., from 0 to 5 or from 0 to 10. Often, people are unsure about the exact degree: 7 or 8? To cover such situations, it is desirable to elicit not a single value but an interval of possible values. However, it turns out that most people are not comfortable with marking an interval. Empirically, it turned out that the best way to elicit an interval is to ask them to draw an oval whose intersection with the 0-to-10 line is the …

Decision Making Under Uncertainty: Cases When We Only Know An Upper Bound Or A Lower Bound, Toshiki Kamio, Gavin Baechle, Vladik Kreinovich

Departmental Technical Reports (CS)

In situations when we have a perfect knowledge about the outcomes of several situations, a natural idea is to select the best of these situations. For example, among different investments, we should select the one with the largest gain. In practice, however, we rarely know the exact consequences of each action. In some cases, we know the lower and upper bounds on the corresponding gain. It has been proven that in such cases, an appropriate decision is to use Hurwicz optimism-pessimism criterion. In this paper, we extend the corresponding results to the cases when we only know an upper bound …

Commonsense "And"-Operations, Javier Tellez, Wenbo Xie, Vladik Kreinovich

Departmental Technical Reports (CS)

In many practical situations, we need to estimate our degree of belief in a statement "A and B" when the only thing we know are the degrees of belief a and b in combined statements A and B. An algorithm for this estimation is known as an "and"-operation, or, for historical reasons, a t-norm. Usually, "and"-operations are selected in such a way that if one of the statements A or B is false, our degree of belief in "A and B" is 0. However, in practice, this is sometimes not the case: for example, an ideal faculty candidate must satisfy …