Physical Sciences and Mathematics Commons^™

Isomerase Activity Of Candida Rugosa Lipase In Conversion Of Racemic Ibuprofen To (S)-Ibuprofen, Saideh Sadat Mortazavi

Open Access Theses & Dissertations

The Candida rugosa lipase-catalyzed Dynamic Kinetic Resolution of racemic ibuprofen methyl ester was optimal at pH 7.6 to produce (S)-ibuprofen in 72 hours. The concentration of various buffers for these reactions ranged from 0.2 to 0.5 M. The commercial lipase was found to be acidic altering the final pH of the reaction mixtures. Dimethylformamide co-solvent maintained the reaction pH better than dimethylsulfoxide, with evidence of the latter functioning as an oxidizing agent. Lower concentrations of ibuprofen methyl ester and higher stirring rates led to faster conversions. The minimal amount of lipase needed was 20 mg/mL buffer. Reaction of (R)-ibuprofen methyl …

Risk Assessment Of Waterborne Cryptosporidium, Victoria Norma Ochoa

Open Access Theses & Dissertations

In an effort to update the risk assessment of waterborne Cryptosporidium an additional and more complete human dose-response dataset of the parasite was used to calculate the risk of infection. The complete data studied contains larger human outcomes than the initial prior risk assessment evaluated by Haas et. al. in 1999. Quantitative analysis of the complete dose-response indicates that it no longer follows the Exponential Model used to estimate the risk for the initial data. The complete dataset appears to provide a better fit with the Beta-Poisson Model and even a dose independent constant risk model, which shows a considerable …

Geophysical Model Of The Cu-Mo Porphyry Ore Deposit At Copper Flat Mine, Hillsboro, Sierra County, New Mexico, Adrian Emmanuel Gutierrez

Open Access Theses & Dissertations

A 3D gravity model of the Copper Flat Mine was performed as part of the exploration of new resources in at the mine. The project is located in the Las Animas Mining District in Sierra County, New Mexico. The mine has been producing ore since 1877 and is currently owned by the New Mexico Copper Corporation, which plans o bringing the closed copper mine back into production with innovation and a sustainable approach to mining development. The Project is located on the Eastern side of the Arizona-Sonora-New Mexico porphyry copper Belt of Cretaceous age. Copper Flat is predominantly a Cretaceous …

Furthering Our Understanding And Assessing The Effectiveness Of Scaling Patterns And Controls Of Land-Atmosphere Carbon Exchange In A Shrubland Of The Chihuahuan Desert With Novel Cyberinfrastructure, Aline Jaimes

Open Access Theses & Dissertations

Over the last century, arid and semiarid regions have undergone intense desertification and in many regions, vegetation has shifted from grassland to shrubland dominated ecosystems. This land cover change has important implications for how desert ecosystems function - especially with regards to land-atmosphere exchange of carbon, water, and energy. Although the extent of desertified landscapes is expected to expand over the next 30 to 40 years, there is a relatively poor understanding of how this state transition will impact ecosystem function and feedbacks to other components of the earth system. Key to addressing this challenge is an improved understanding of …

A Long- And Short-Run Analysis Of Electricity Demand In Ciudad Juarez, Ericka Cecilia Mendez

Open Access Theses & Dissertations

Economic growth and appliance saturation are increasing electricity consumption in Mexico. Annual frequency data from 1990 to 2012 are utilized to develop an error correction framework that sheds light on short- and long-run electricity consumption behavior in Ciudad Juarez, a large Mexican metropolitan economy at the border with the United States. The results for this study reveal that electricity is an inelastic normal good in this market. Moreover, natural gas is found to be a weak complement to electricity. With regards to the customer base in this urban economy, population, employment, and income exercise positive and statistically significant impacts on …

Impact Of Zinc Oxide Nanoparticles On Green Pea Plant & Seed Quality And Effects On Physiological Traits Of Green Peas, Corn, And Zucchini By Silver Nanoparticles, Arnab Mukherjee

Open Access Theses & Dissertations

The production and use of numerous engineered nanomaterials (ENMs) have increased exponentially over the past decade. Nanoparticles (NPs), ENMs possessing diameter between 1-100 nm, (NPs), are widely used in many applications. Worldwide consumption of NPs has increased their possible release into the environment. This, in turn, has elevated the extent of the potential impacts of NP exposure to living and non-living organisms. This is why the assessment of the impact of NPs on different environmental components, especially on plants, the producer in the food web, has become a very important aspect of nano-ecotoxicology. However, studies focusing on phytotoxicity and effects …

Development Of A Transferable Student Engagement And Knowledge Retention Framework For The Earth Sciences, Sunay Palsole

Open Access Theses & Dissertations

The earth sciences play an important role in engaging students in science and in science, technology, engineering and mathematics (STEM) disciplines, because of the integrative nature of the disciplines. It then becomes important for us to provide an engaging experience for students taking earth science courses, because it serves a dual purpose of possibly increasing new majors in the discipline and helping to create a science literate population.

Given that a majority of students in the larger introductory courses are non-majors, it behooves us to explore alternative engagement techniques and measure their efficacy in student engagement, which in turn can …

Digitally Manufactured Spatially Variant Photonic Crystals, Javier Jair Pazos

Open Access Theses & Dissertations

Metamaterials and photonic crystals are engineered composites that exhibit electromagnetic properties superior to those found in nature. They have been shown to produce novel and useful phenomena that allow extraordinary control over the electromagnetic field. One of these phenomena is self-collimation, an effect observed in photonic crystals in which a beam of light propagates without diffraction and is forced to flow in the direction of the crystal. Self-collimation however, like many of the mechanisms enabled through dispersion engineering, is effective in directions only along the principal axes of the lattice. To this effect, a general purpose synThesis procedure was developed …

Fast Algorithm For Finding Lattice Subspaces In Rn And Its Implementation, Andrew Martin Pownuk

Open Access Theses & Dissertations

There are known necessary and sufficient conditions for a subspace of Rm to be lattice-ordered. Let Y = {y1,…,ym} and yi are rows of the matrix X. A subspace ⟨X⟩, of linear space generated by the set X of n linearly independent positive vectors is lattice-ordered if and only the set X admits a fundamental set of indices I, which means that the subset YI ⊆ Y of vectors indexed by I is linearly independent, and every vector from Y\YI is a nonnegative linear combination of vectors form YI.

In economics it is possible to prove that the minimum-cost insured …

Three Essays On Social/Political Structures And Icts Use, Seungeui Ryu

Open Access Theses & Dissertations

My research identifies how social structures affect the use of the Internet and/or a mobile chat application and how the Internet impacts the political structure of a nation. In my first essay of the 3-essay Dissertation, I am designing three models based on social structure theory that are used to study the Internet and a popular mobile chat application's use by managers in South Korea, with the help of a survey instrument. In my first essay, the contribution is on i) testing a model of manager's personal behavior on Information and Communication Technology (ICT) use at the individual level involving …

Finite Density Qed At Strong Magnetic Field, Paul Lee Springsteen

Open Access Theses & Dissertations

In this Thesis we study the effect of a dense medium on the quantum properties of a relativistic electron-positron plasma under a magnetic field. From the calculation of the photon polarization operator depending on temperature, chemical potential, and the magnetic field; we study how the electric susceptibility of the strongly magnetized plasma is charged with temperature and density. In the same manner we study the dependence of the Debye mass with density. Then we investigated the phenomenon of magnetic catalysis of chiral symmetry breaking for a dense medium. We found that there exist a critical value of the chemical potential …

Homeomorphisms Between Pairs Of Genus Two Handlebodies And Separating Circles In Their Boundaries, Daniel Orlando Vazquez

Open Access Theses & Dissertations

A known result in low-dimensional topology is that every incompressible surface properly embedded in a genus two handlebody is boundary compressible. This result produces a pair consisting of a genus two handlebody and a separating curve in its boundary.

We study particular examples of genus two handlebodies and essential simple closed curves which separate their boundaries. The aim of this paper is to give our own construction of separating curves on the boundary of genus two handlebodies and compare them with previously studied pairs. These constructions involve taking 2n arcs on either side of a waist disk of a genus …

Alkali Promoted Molybdenum (Iv) Sulfide Based Catalysts, Development And Characterization For Alcohol Synthesis From Carbon Monoxide And Hydrogen, Belinda Delilah Molina

Open Access Theses & Dissertations

For more than a century transition metal sulfides (TMS) have been the anchor of hydro-processing fuels and upgrading bitumen and coal in refineries worldwide. As oil supplies dwindle and environmental laws become more stringent, there is a greater need for cleaner alternative fuels and/or synthetic fuels. The depletion of oil reserves and a rapidly increasing energy demand worldwide, together with the interest to reduce dependence on foreign oil makes alcohol production for fuels and chemicals via the Fischer Tropsch synthesis (FTS) very attractive. The original Fischer-Tropsch (FT) reaction is the heart of all gas-to-liquid technologies; it creates higher alcohols and …

A Study Of Ti-Doped Wo3 Thin Films Using Comparative Theoretical And Experimental Approach, Aurelio Paez

Open Access Theses & Dissertations

Metal oxides like Tungsten Oxide (WO3) are well documented and characterized in the literature, with uses in darkening windows and mirrors, flat computer displays, solar panel cooling, and sensors (of interest in this study). Ti doping of WO3 is less documented and the focus of this study. Sample thin films of pure WO3 and varyingly Ti doped WO3 were prepared using Radio Frequency magnetron sputtering (RF) (13.56 MHz) to grow thin films on a silicon substrate. This study aims to compare multiple Ti doping percentages in WO3 theoretically and then compare with experimental data taken from thin films of various …

Exploring The Hydrogeologic Controls On Brackish Water And Its Suitability For Use In Hydraulic Fracturing: The Dockum Aquifer, Midland Basin Texas, Francisco Ruben Reyes

Open Access Theses & Dissertations

Water scarcity in arid regions can limit or impede certain hydrocarbon production activities, such as hydraulic fracturing and well drilling. The Midland Basin, a major oil-producing area in semi-arid far west Texas and the eastern sub-basin of the Permian Basin, is already impacted by limited freshwater availability. A typical tight oil well in the Midland Basin requires ~3.8-11.4 x 103 m3 of water per fracture treatment (Nicot et al., 2012). Despite draught conditions and limited resources, data for 2011 indicate freshwater comprises ~70% of the water used in hydraulic fracturing in the Midland basin. Thus, the Midland Basin represents an …

Synthesis And Characterization Of Fluorophores For The Detection Of Lanthanides And Actinides, Robinson I. Roacho

Open Access Theses & Dissertations

A series of fluorophores based in the boron dipyrromethene (BODIPY) family were synthesized and characterized. These fluorophores have the capacity of being introduced to a carbamoyl methyl phosphine oxide (CMPO) lanthanide/actinide extractant. These blue, green and red emission fluorophores show high thermal/moisture stability and high fluorescence efficiencies. The fluorescence intensity seems to be dependent on the restricted rotation about the C(8)-C bond in 8-Ph-BODIPY. By taking advantage of this feature, a hydroxyl- containing BODIPY with high fluorescence intensity was synthesized to be incorporated to a CMPO carboxylic acid via esterification. Unfortunately, we did not observe an optical response upon the …

Platform-Independent Data Locality Analysis To Predict Cache Performance On Abstract Hardware Platforms, Sonish Shrestha

Open Access Theses & Dissertations

This research is part of a co-design project that has the goal of designing hardware systems to match application requirements and efficiently mapping applications to hardware. This thesis is focused on optimizing the platform cache memory hierarchy configuration. To determine application requirements, we characterize the application using platform- independent locality metrics. Next we use locality data and an analytical model to predict cache an application performance of sequential versions of application codes for various cache configurations. After using an analytical model to select a candidate set of cache memory hierarchy configurations, we used architectural simulation to test the selection for …

Evaluation Of Ozone Trends In Southern Doña Ana County, New Mexico Thru Wind Rose Analysis And Use Of Noaa Hysplit Model, Maria Aurelia Sisneros

Open Access Theses & Dissertations

The objective of this study was to determine whether increasing ozone concentrations in 2012 and 2013 at the Santa Teresa air quality monitor in Doña Ana County, New Mexico were due to a local point source impacting this monitor only or part of a regional phenomenon that affects all the monitors within the Paso del Norte Region. In addition, the study focused on identifying local and regional/long-range source areas contributing transport ozone to the study area (southern Doña Ana County).

The study showed that increasing ozone levels were not unique to the Santa Teresa monitor due to the fact that …

A New Bivariate Distribution With Applications, Sathya Amarasekara

Open Access Theses & Dissertations

We construct a bivariate distribution of (X, Y ) by assuming that the conditional distribution of Y given X is a two-parameter Gamma (s, ν(x)), where the scale parameter depends on X. If X is assumed to be any distribution, then clearly the joint distribution is well defined in all cases. We will study this new distribution by developing all possible properties, moments, shapes and estimation of parameters with a view towards applications of the distribution to data from many random number generation methods.

A Block Precondtioner For A Mixed Finite Element Method For Biot;S Equations, Maranda Lee Bean

Open Access Theses & Dissertations

In this Thesis, we explore the solution methods for the linear system resulting from a mixed finite element method applied to the Biot's consolidation model. This model describes the coupled interactions between a porous solid and the fluid contained within it. Specifically, we use a method developed by Yi [Numer. Methods for PDEs, 29(5), pp. 1749-1777] that expands Biot's system to include fluid pressure, solid displacement, fluid flux and total stress as primary unknowns.

As the resulting linear system is a large, sparse, saddle point system, we attempt to solve this system via a Schur complement preconditioned iterative method. Using …

Modeling Tidally Driven Coulomb Failure At Strike-Slip Linea On Europa, Marissa Elizabeth Cameron

Open Access Theses & Dissertations

The surface of Europa is crosscut by a dense network of fractures and there are many candidate faults for studying past tectonic activity. To better understand the role of tidal stress sources and implications for faulting on Europa, we investigate the relationship between shear and normal stresses at four fault zones: Agenor Linea, Rhadamanthys Linea, Conamara Chaos (Agave/Asterius Linea), and Astypalaea Linea, offering a unique comparison of geological activity of fractures residing in geographically diverse locations of Europa. Assuming tidal diurnal and non-synchronous rotation (NSR) stresses are the primary mechanisms for strike-slip tectonism, here we investigate the mechanics of Coulomb …

Essays On The Digital Divide, Belal Abdelfattah

Open Access Theses & Dissertations

The digital divide is a phenomenon that is globally persistent, despite rapidly decreasing costs in technology. While much of the variance in the adoption and use of information communication technology (ICT) that defines the digital divide can be explained by socioeconomic and demographic variables, there is still significant unaccounted variance that needs to be explained if the world's population is expected to be brought more fully into the digital age. The present research addresses this need with three cross-country studies. Study 1 primarily investigates the time individuals spend with traditional media sources as a likely explanation for their frequency of …

Natural Selectivity Of Nickel And Vanadium In Crude Oil, Olienka P. De La O Fernandez

Open Access Theses & Dissertations

Nickel and Vanadium have always been found in crude oil all around the world. The metal content is found mainly in porphyrin structures in the asphaltene fraction of the petroleum. In order to determine the reason for this natural preference, a set of experiments testing thermodynamics, kinetics, and other factors were performed. Candidate metalloporphyrins containing Vanadyl, Chromium, Iron, Nickel, Copper and Zinc were analyzed through chemical reactions characterized using Silica Column Chromatography, HPLC, MS and UV-Visible. Theoretical analysis of the stability of metalloporphyrins was conducted using DFT/NRLMOL for computational calculation. The analysis of all factors leads us to conclude that …

Environmental Assessment Of Used Motor Oil In The Ciudad Juarez-El Paso Area, Alma Leticia Figueroa

Open Access Theses & Dissertations

As a hazardous waste generated in large amounts worldwide, used motor oil (UMO) is an important issue for environmental science. UMO contains the carcinogenic and mutagenic compounds Polycyclic Aromatic Hydrocarbons (PAHs). Unless properly managed and disposed of PAHs remain in the environment, principally in sediments and soil. From such environmental sinks, PAHs can migrate to watersheds contaminate drinking water, and damage ecosystems and human health.

Generators of used oil include "businesses that handle used oil through commercial or industrial operations or from the maintenance of vehicles and equipment," (United States Environmental Protection Agency (USEPA), 2013). An example of such a …

Why Ricker Wavelets Are Successful In Processing Seismic Data: Towards A Theoretical Explanation, Afshin Gholamy Salehabady

Open Access Theses & Dissertations

In many engineering applications ranging from engineering seismology to petroleum engineering and civil engineering, processing seismic data plays a key role. In processing seismic data, it turns out to be very efficient to describe the signal's spectrum as a linear combination of Ricker wavelet spectra.

In this Thesis, we provide a possible theoretical explanation for this empirical efficiency. Specifically, signal propagation through several layers is discussed, and it is shown that the Ricker wavelet is the simplest non-trivial solution for the corresponding data processing problem, under the condition that the described properties of the approximation family are satisfied.

An Optimization Of Neighbor Discovery In Mobile Ad Hoc Networks, Felipe Jovel

Open Access Theses & Dissertations

This Thesis aims to improve the performance of Mobile Ad Hoc Networks (MANETs) that use soft-state signaling for neighbor discovery, specifically OLSR. In particular, it uses simulations and previous work based on experiments conducted on a physical test bed to study the behavior of the neighbor-discovery algorithm used by OLSR to identify and explore ways to optimize the neighbor-discovery process. Candidate optimizations include the actual and relative settings of the refresh and expiry timers used by the algorithm.

Previous studies focused on understanding how the settings of the algorithms Hello Interval (δ) and TC Interval refresh timers affect network performance …

2tl: A Raid I/O Scheduling Algorithm For Simultaneously Providing Latency And Throughput Guarantees, Yipkei Kwok

Open Access Theses & Dissertations

It is increasingly common for applications to require that data read from and written to a shared storage system be delivered within a specified amount of time (usually milliseconds), called a latency requirement, or be delivered at a specified rate (measured in megabytes per second), called a throughput requirement. Given an input/output (I/O) workload, which consists of the streams of I/O requests of a set of applications, the storage system, via its I/O scheduler, is expected to simultaneously meet the workload's latency and throughput requirements. In addition, it is expected to provide performance guarantees, i.e., guarantees that it will meet …

Experimental Investigation Of Syngas Flame Stability Using A Multi-Tube Fuel Injector In A High Pressure Combustor, Sergio Elzar Maldonado

Open Access Theses & Dissertations

Over 92% of the coal consumed by power plants is used to generate electricity in the United States (U.S.). The U.S. has the world's largest recoverable reserves of coal, it is estimated that reserves of coal will last more than 200 years based in current production and demand levels. Integrated Gasification Combined Cycle (IGCC) power plants aim to reduce the amount of pollutants by gasifying coal and producing synThesis gas. SynThesis gas, also known as syngas, is a product of coal gasification and can be used in gas turbines for energy production. Syngas is primarily a mixture of hydrogen and …

Neighbor Discovery Message Hold Times For Mobile Ad Hoc Networks, Joshua Lee Mccartney

Open Access Theses & Dissertations

We present the results of an experimental study designed to understand the impact of neighbor discovery message hold times on network performance measures for a mobile ad hoc network. A physical testbed of pseudo-mobile nodes using the OLSR routing protocol was used for our experiments. We found statistically significant evidence to suggest that setting the neighbor discovery message hold times close to the neighbor discovery message interval time results in the best overall network performance.

Super Resolution Pump-Probe Microscopy With Point Spread Function Engineering, Farzaneh Mohajerani

Open Access Theses & Dissertations

Since the last decade, new techniques have made optical microscopy break the diffraction barrier of resolution where all of them are based on molecular fluorescence. Among them, stimulated emission depletion microscopy (STED) has reached less than 25 nm resolution by engineering the point spread function. However, the existing obstacles associated with fluorescence tagging makes it desirable to achieve label-free imaging. Recently the pump-probe method has made it possible to obtain image contrast from molecular absorption and vibration signatures that do not depend on fluorescence. We introduce Super Resolution Pump-Probe Microscopy (SRPPM), in which we combine both PSF engineering method and …