Physical Sciences and Mathematics Commons^™

Rational Design Of Composite Nanomaterials For Water Treatment Applications, Mariana Marcos-Hernandez

Open Access Theses & Dissertations

Water quantity and quality have been affected in communities all around the world due to population growth, pollution, changes in land use, and climate change. In order to cope with existing and anticipated water demands and shortages, the use of treated or reclaimed water is an ongoing alternative that has helped communities all over the world address this problem. The adaptation of nanotechnology to traditional water and wastewater treatment processes offers new opportunities in technological developments. Unique size-dependent properties such as: high surface to mass ratio, high reactivity, high sorption capacities, fast dissolution, superparamagnetism, among others, provide high-tech efficient materials …

Mathematical Modeling Of Potassium Modulated Viral Infection, Zaira Elizabeth Mather

Open Access Theses & Dissertations

In recent years, there is a growing interest in the investigation of using potassium to treat virus infections. In the region of infection, there is a biological observation of extracel- lular potassium level being typically very low whereas the intracellular potassium levels are much higher. There are numerous biological studies showing that elevated potassium levels in the extracellular membrane tends to block virus infections. A recent effort in this direction is a collaborative research conducted by mathematicians and biologists from the University of Texas at El Paso, New Mexico State University, and the University of New Mexico, where we develop …

Game-Theoretic Deception Modeling For Distracting Network Adversarie, Mohammad Sujan Miah

Open Access Theses & Dissertations

In this day and age, adversaries in the cybersecurity space have become alarmingly capable of identifying network vulnerabilities and work out various targets to attack where deception is becoming an increasingly crucial technique for the defenders to delay these attacks. For securing computer networks, the defenders use various deceptive decoy objects to detect, confuse, and distract attackers. By trapping the attackers, these decoys gather information, waste their time and resources, and potentially prevent future attacks. However, we have to consider that an attacker with the help of smart techniques may detect the decoys and avoid them. One of the well-known …

Evolution Of The Magnetic Properties On Van Der Waals Layered Magnets Via Pressure And Proton Irradiation, Rubyann Olmos

Open Access Theses & Dissertations

Probing the magnetism in quasi two-dimensional materials has the potential in driving their properties towards future use in spin electronic based devices. Studying such layered magnets will enable the scientific community to uncover tunable exotic phases such as superconductivity, quantum paramagnetism, etc. This work examines the influence of two types of external perturbations, namely, the pressure and proton irradiation, on the magnetic properties of several compounds in the van der Waals crystal family.

Pressure has been found to induce structural and magnetic phase transitions in many of these materials. Using hydrostatic pressure as a disorderless approach to manipulate the interlayer …

Material Synthesis And Machine Learning For Additive Manufacturing, Jaime Eduardo Regis

Open Access Theses & Dissertations

The goal of this research was to address three key challenges in additive manufacturing (AM), the need for feedstock material, minimal end-use fabrication from lack of functionality in commercially available materials, and the need for qualification and property prediction in printed structures. The near ultraviolet-light assisted green reduction of graphene oxide through L-ascorbic acid was studied with to address the issue of low part strength in additively manufactured parts by providing a functional filler that can strengthen the polymer matrix. The synthesis of self-healing epoxy vitrimers was done to adapt high strength materials with recyclable properties for compatibility with AM …

Context Dependence Of Warming Induced Shifts In Alpine Soil Microbial Functions, Sydne Rose Spinella

Open Access Theses & Dissertations

Atmospheric warming is occurring due to anthropogenic release of carbon dioxide. Climate change has the potential to increase microbial activity in soil, where a significant amount of terrestrial carbon is stored, which may lead to release of this soil carbon into the atmosphere, positively feeding back to global temperature rise. Understanding how the indirect impacts of climate warming, like shifts in plant community composition, affect soil microbes can improve predictions of ecosystem functions and services under climate change. This project examined direct and indirect consequences of warming on microbial processes using independent and combined treatments of experimental warming and dominant …

Integration Of Genetic Isothermal Amplification On Low-Cost Hybrid Paper/Polymer Microfluidic Biochips For High Sensitivity Point-Of-Care Disease Diagnosis, Hamed Tavakoli

Open Access Theses & Dissertations

Infectious diseases and cancer have been two main causes of global death and disability, leading to a significant impact on public health and economies globally. Early diagnosis of these diseases can improve prevention, treatment, and prognosis in clinical practice. However, current laboratory diagnostic approaches require expensive and bulky equipment, well-trained personnel, and time-consuming processes, which puts a great challenge to conventional methods to address, especially in resource-limited settings. Microfluidic lab-on-a-chip presents a unique opportunity for various biomedical applications due to multiple advantages such as low reagent consumption, integration, miniaturization, portability, and automation. Since different microfluidic platform substrates have their advantages …

Developing And Applying Computational Algorithms To Reveal Health-Related Biomolecular Interactions, Yixin Xie

Open Access Theses & Dissertations

Computational biology is an interdisciplinary area that applies computational approaches in biological big data, including protein amino acid sequences, genetic sequences, etc., which is widely used to analyze protein-protein interactions, make predictions in drug discovery, develop vaccines, etc. Popular methods include mathematical modeling, molecular dynamics simulations, data science mythology, etc. With the help of computational algorithms and applications, drug development is much faster than traditional processes, as it reduces risks early on in a drug discovery process and helps researchers select target candidates that have the highest potential for success. In my doctoral research, I applied multi-scale computational approaches to …

Suitability Of Low-Cost Additive Manufacturing For Polymer Electrolyte Fuel Cells, David Alexander

Open Access Theses & Dissertations

The purpose of this dissertation is to study the feasibility of low-cost additive manufacturing to fabricate polymer electrolyte fuel cell bipolar plate materials. Traditional manufacturing techniques include molding, milling, hollow embossing, hydro-forming, rolling, and electromagnetic forming. These processes are employed when a design has been selected due to higher costs at low volumes. The combination of high initial costs and bipolar plates being the most expensive component of the polymer electrolyte fuel cell creates incentive to mitigate this obstacle. The feasibility of low-cost additive manufactured bipolar plates will be proven by fabrication, post-processing, and characterization of printed test specimen. The …

Tuning Nanoscale Molecular Heterogeneity To Improve Co2 Transport And Binding In Co2 Capture Solvents, Omar Avina

Open Access Theses & Dissertations

Aqueous amine-based technology has been considered the most promising carbon capture solution for post-combustion gas from fossil fuel plants. However, solvent degradation and the high energy cost associated with removing CO2 from the solvent, known as regeneration, have hindered its widespread implementation. It has been proposed that utilizing a water lean solvent, in contrast to aqueous amines, can decrease the required heat to regenerate the solvent. Additionally, Malhotra et al. proposed that controlling the viscosity can help increase the mass transport properties of CO2 in the solvent. A recent study on CO2 binding organic liquids (CO2BOLs) found them to exist …

Nanotechnology-Based Approaches To Mitigate Environmental Pollutants -- Induced Neurological Disorders, Jyoti Ahlawat

Open Access Theses & Dissertations

Neurodegenerative diseases such as Parkinson's disease (PD), Alzheimerâ??s Disease (AD) and Huntingtonâ??s Disease (HD) have no cure despite intensive research efforts geared towards therapeutics development. In the USA, patients with PD and AD alone cost the nation ~ $200 billion annually in patient care and lost productivity. Therefore, there remains an urgent and unmet need to develop novel drugs and drug carriers with the potential to slow down, halt and ideally reverse the course of neurodegenerative disorders. The dissertation focuses on developing approaches towards targeting PD using multifactorial mechanisms including the targeting of protein aggregation and oxidative stress. This is …

Low-Lying Spin-Flip Excitonic States Of ����12��12 (��������)16 [��2��]4 Molecule (Mn12 − ����), Karma Dema

Open Access Theses & Dissertations

Molecules and materials constructed from Mn atoms offer diverse assortments of geomet- rical and spin structures. The diversity of structures, in comparison with other transition metals, along with nature’s decision to use a Mn-based molecule to catalyze solar-driven water splitting and oxygen evolution, suggests that there is indeed something special about the location of Mn valence electrons, both energetically and geometrically, that endows Mn with its multifaceted behaviors that, in turn, provide such chemical, physical and mag- netic diversity. Based upon recent work on the Mn3 monomer and the Mn(taa) there is an expectation that Mn�� �� �� centers can …

Method Development For Preconcentration And Quantification Of Critical And Valuable Elements In Permian Basin Produced Waters, Joshua Matthew Lewis

Open Access Theses & Dissertations

Produced waters are a voluminous byproduct of unconventional oil and gas production. Produced water volumes are primarily addressed by subsurface reinjection through saltwater disposal wells (SWDs) and reuse within the oil and gas industry. Oil and gas operators continue to evaluate and trial novel methods to improve produced water handling, and reduce freshwater use, and disposal volumes. Here, we present results for method development to quantify Critical and Valuable Elements (CVEs; defined here as the lanthanide series, high field strength elements, industrial elements and precious metals in brines. CVE concentrations in produced waters and other high-salinity waters are poorly understood …

Covid Synergy: A Machine Learning Approach Uncovering Potential Treatment Combinations For Sars-Cov-2, Jason Eden Sanchez

Open Access Theses & Dissertations

For more than two years, the COVID-19 pandemic has upended the lives of billions of individualsworldwide leading to disruptions in healthcare, the economy and society at large. As the pandemic enters its third year, the human impact cannot be overstated and the need to develop effective pharmaceuticals remains. Though there currently exits FDA-approved medications for COVID-19, the emergence of novel variants, such as Omicron, highlights the importance of discovering new therapies which will continue to be effective regardless of the pandemicâ??s progression. Because discovering new medications is a costly and timeintensive endeavor, my approach entails drug repurposing to test medications …

Supercritical Co2 Recompression Closed Brayton Cycle Analysis, Andres Eduardo Gutierrez Hernandez

Open Access Theses & Dissertations

On this research, the results of an analysis made of a Supercritical Carbon Dioxide (sCO2) Recuperated Closed Brayton Cycle (RCBC) done by performing theorical calculations and comparing it to the results obtained with the use of the software ASPEN Plus will be presented. To demonstrate and determine that this software is a useful tool for modeling the proposed type of cycle, a preliminary comparison was made to verify with previous studies found in literature. A comparison and analysis between the possible working fluids and thermal energy sources was also performed to emphasize the decision of using CO2 as the cycle …

Examining The Effects Of Information And Communication Technologies In The Legal Representation Of Latin American Asylum Seekers, Victor M. Portillo Ochoa

Open Access Theses & Dissertations

The purpose of this thesis was to explore how legal defense nonprofit organizations (NPO) are using Information and Communication Technologies (ICT) to provide legal defense for asylum seekers and improve the conditions of immigrants at detention centers. In addition, this research explored the impact of ICTs on legal defense NPOs, bottlenecks, and security implications when supporting vulnerable communities. ICTs profoundly impacted the way we interact in a post-pandemic world, and it presents new challenges and possibilities for legal defense nonprofit organizations that are helping vulnerable communities. This study consists of staff and volunteers from different legal defense nonprofit organizations NPOs …

Interval Constraint-Solving Strategies For Solving Dynamical Systems, Angel Fernando Garcia Contreras

Open Access Theses & Dissertations

There are abundant phenomena that humans can describe through mathematical models. Dynamical systems are one such type of model, describing the behavior of phenomena that change over time. For example, a scientist can measure and analyze an insect's wing parameters and movements to create a dynamical system of that behavior. We can then use this model in different applications, such as creating a nano vehicle with insect-like propulsion.

For many real life problems, there exist analytical solutions. These can represent a full description of the state of a dynamical system at any moment in continuous time. However, in most practical …

Tectonomagmatic Evolution Of Northwestern Mexico, And Applications Of Machine Learning In Economic Geology, Jose Antonio Garcia

Open Access Theses & Dissertations

The work presented here was conducted in two study areas: La Preciosa mining project (Chapters 1 and 2) and Ray Mine (Chapter 3). Chapter 1 of this dissertation contributes to the tectonomagmatic evolution of northwestern Mexico by focusing on the temporal changes in magma source(s) regions, magma generation processes, and tectonic implications. In this chapter, I provide thin section analyses, whole rock geochemistry, in-situ zircon U-Pb ages and Hf isotope compositions of subsurface lithologies from La Preciosa mining project; located in the northwestern corner of Mesa Central, Durango, Mexico. The newly acquired data identified five magmatic events. The first consists …

Relationship Between Sustainability Determinant Variables For Usa, India, China During The Sustainability Awareness Years From An Energy Usage Perspective And Its Relation To Environmental Kuznets Curve: Analysis By Linear Regression, Krishnan Iyer

Open Access Theses & Dissertations

Sustainable development promotes economic growth alongside environmental quality preservation and minimizes greenhouse gas emissions .The Environmental Kuznets curve (EKC) shows that, as countries transition from low income to higher income levels of economic development it leads to a deterioration of the environment, but after a certain level of economic growth, environmental quality is preserved alongside economic growth to a good extent and makes the developmental model sustainable. In this research we perform Linear Regression to test the effect of sustainability determinant variables on Total greenhouse gas emissions and perform a comparative study of the test results on the world’s leading …

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. …