Physical Sciences and Mathematics Commons^™

Structural And Tectonic Investigation Of A Transpressional System, Chugach Metamorphic Complex, Southern Alaska, Mitchell Ryan Scharman

Open Access Theses & Dissertations

Late Cretaceous to Eocene ridge subduction beneath the Mesozic Chugach terrane accretionary complex resulted in the formation of the Chugach metamorphic complex, and anomolus near trench plutonism of the Sanak-Baranof plutonic belt. The Chugach metamorphic complex (CMC), southern Alaska, is a high-temperature/low-pressure metamorphic belt, that offers a down plunge view of the mid- to lower-crust of a dextral transpression system. A distinct progression of deformation is recognized in the complex: 1) D1 contraction throughout the Chugach accretionary complex, 2) D2 margin parallel extension and horizontal simple shear, associated with subduction of higher ridge topography, followed by 3) D3 dextral transpression …

On Constrained Optimization Schemes For Joint Inversion Of Geophysical Datasets, Uram Anibal Sosa Aguirre

Open Access Theses & Dissertations

In the area of geological sciences, there exist several experimental techniques used to advance in the understanding of the Earth. We implement a joint inversion least-squares (LSQ) algorithm to characterize one dimensional Earth's structure by using seismic shear wave velocities as a model parameter. We use two geophysical datasets sensitive to shear velocities, namely Receiver Function and Surface Wave dispersion velocity observations, with a choice of an optimization method: Truncated Singular Value Decomposition (TSVD) or Primal-Dual Interior-Point (PDIP). The TSVD and the PDIP methods solve a regularized unconstrained and a constrained minimization problem, respectively. Both techniques include bounds into the …

Airborne Lead In El Paso, 1977-1999, Ingrid B. Camacho

Open Access Theses & Dissertations

Airborne lead is an important component of the biogeochemical make-up of ambient air. Most of the lead emitted to the atmosphere has been in the form of particulate matter.

This study evaluated airborne lead levels in the El Paso airshed at different intervals over the span of three decades between 1977 and 1999. Levels of lead and related metals for a number of years and from a number of sampling stations in El Paso were available from Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analyses previously conducted in Prof. Pingitore's laboratory at UTEP.

Data consisted of some 200 samples, each a …

A Symbolic Approach Towards Constraint Based Software Verification, Shubhra Datta

Open Access Theses & Dissertations

Verification and validation (V&V) are two components of the software engineering process that are critical to achieve reliability that can account for up to 50% of the cost of software development. Numerous techniques ranging from formal proofs to testing methods exist to verify whether programs conform to their specifications. Recently, constraint programming techniques for V&V have emerged : they use the idea of proof by contradiction. They typically aim at proving that the code is inconsistent with the negation of the specification, which means that the software conforms to its specifications. Although the framework seems straightforward, the number of generated …

Metaphors, Metonymies, Modes And Linear Algebra, Persis Samanta Beaven

Open Access Theses & Dissertations

The analysis focused on the presence of different thinking modes, metonymies, and metaphors found on the interview responses to questions related to linear independence, span, and spanning sets of four students taking their first linear algebra course at the college level. The findings provide insight of how first year linear algebra students move from one thinking mode to another and what kind of metonymies and metaphors are used to construct new knowledge. The main purpose of this research was to document and determine the main characteristics that categorize the four students' reasoning.

The Isomorphisms Between The Upper And Lower Triangular Matrix Algebras, Zahi Fawaz

Open Access Theses & Dissertations

Since matrix equations with triangular matrices are easier to solve, the triangular matrices are very important in mathematics. For instance, the LU decomposition gives an algorithm to decompose any invertible matrix A into two triangular factors: a lower triangle matrix L and an upper triangle matrix U. Moreover, the inverse of a triangular matrix is also triangular. Also the product of two lower triangular matrices produces a lower triangular matrix, the same apply for upper triangular matrices. A lot of important notions, such as the determinant, the eigenvalue problem and many others are easy to handle when we are working …

Optimal Control Applied To A Discrete Time Influenza Model, Paula Andrea Gonzalez Parra

Open Access Theses & Dissertations

For the last decades, mathematical epidemiological models have been used to understand the dynamics of infectious diseases and guide public health policy.

In particular, several continuous models have been considered to study influenza outbreaks and their controls policies. However, most epidemiological data is discrete; therefore, a discrete formulation is more convenient to compare collected data with the output of the model. We introduce a discrete time model in order to study optimal control strategies for influenza transmission.

In our model, we divide the population into four classes: susceptible, infectious, treated, and recovered individuals.

In particular, we evaluate the potential effect …

Evidence Of Ancient Rifts Beneath Texas, Keisuke Irie

Open Access Theses & Dissertations

Continental rifts are defined as geological features where Earth's lithosphere is pulled away by surface expansion of the Earth. Their physiographic features include linear rift valleys associated with active volcanism. Many rifts fail to split a continent and ancient rifts that failed to split can be found by using seismic waves to image these ancient structures. Using seismic data collected by EarthScope USArray stations in Texas, teleseismic receiver functions was calculated and utilized surface wave dispersion curves to simultaneously invert for the 2D velocity structure beneath each seismic station. EarthScope is a scientific program funded by NSF that provides geophysical …

Principal Differential Analysis With Covariates : A Simulation Study On The Effect Of The Smoothing Parameters, Indika Varuna Mallawaarachchi

Open Access Theses & Dissertations

Principal Differential Analysis deals with functional data. The word functional data refers to a collection of curves that are independent and measured on a dense grid of time points in an interval. These time points can be equally or unequally spaced. A differential equation is believed capable of capturing the features of these n curves.

Ramsay(1996) first introduced Principal Differential Analysis (PDA) as an alternative to the Principal Component Analysis(PCA). PDA finds a linear differential equation that captures features of a collection of curves, in order to have a low dimensional approximation for functional data. PDA is based on the …

Dispersion Geochemistry At Different Scales At The Nopal I Deposit, Peña Blanca Uranium District, Chihuahua, Mexico, Katrina Pekar-Carpenter

Open Access Theses & Dissertations

The Nopal I mine in the Peña Blanca Uranium District, Chihuahua, Mexico is a natural analog for the geologic storage of nuclear waste. This dissertation presents data from two sites within Nopal I: 1) the PB-1 core, which was drilled along the extent of uranium mineralization in the Nopal I mine; and 2) a high-grade stockpile boulder from the mineralized Nopal tuff.

The PB-1 core allowed an investigation into the mineralogical and geochemical changes that are important to research on a nuclear waste repository. Five zones were determined to control these changes: 1) Zone 1, the primary uranium mineralization (quartz-uraninite-pyrite-kaolinite-ilmenite); …

Development Of An Expert System To Aid In The Selection Of Sustainability Design Engineering Methods, Pedro Renato Acosta

Open Access Theses & Dissertations

The objective of this thesis is to present the development of an expert system to aid designers in the selection of design methods, in particular for sustainability methods. When practicing engineers need help in their design process, they look for design methods and tools; this is a challenge especially for inexperienced engineers in the sustainability area. Engineers, due to time constrains, will only utilize one or few methods during their professional life. The origin of this situation can be traced to engineering education, where it is typical that an instructor prefers one or few methods in particular, and even when …

Development And Testing Of An Unmanned Aircraft System For Environmental Science, Jerald James Brady

Open Access Theses & Dissertations

For some environmental science applications, Unmanned Aircraft Systems (UASs) are increasingly recognized for their capacity to collect remotely sensed data in a safer, more efficient and effective manner than is permitted with manned aircraft and satellite remote sensing platforms. To date, however, technological, human, and other challenges have constrained adoption of UASs in the environmental sciences. This study developed and tested a new UAS for an archetypical environmental science research group (stakeholder) composed of non-UAS experts. Specifically, this thesis: 1) Assessed the research and operational needs of the stakeholder to determine the optimum UAS platform; 2) Developed an Unmanned Aerial …

Decentralized Fault Tolerant Caching With Memcached, Bivas Das

Open Access Theses & Dissertations

Recent changes in web trends not only have increased popularity of web services, but also have vastly increased usage. Popular techniques, such as web-caching, used by content and service providers to provide faster content delivery at user end, is not enough to keep up, due to diversity and dynamic nature of web-contents.

Emerging ideas to cache on the server side, for faster content generation and delivery, is currently in use by popular web-service providers. One example of such caching system is Memcached. However, memcached, a distributed high performance caching system, is ineective in dynamic organization of itself and scaling when …

Estimating The Effect Of Dust And Low Wind Events On Hospitalizations For Asthma While Adjusting For Hourly Levels Of Air Pollutants, Priyangi Kanchana Bulathsinhala

Open Access Theses & Dissertations

El Paso, Texas is known as one of the dust hotspots in North America. We explore the effect of dust and low wind events on asthma admissions in El Paso, Texas between 2000 and 2005. Conditional logistic regression with a case-crossover design was used to estimate the probability of hospitalization after dust and low wind events while controlling for pollutants with hourly monitor measurements, and weather. The historical functional linear model is used to incorporate the hourly pollutant measures into the regression model with a continuous lag, as an alternative to a distributed lag model based on daily averages. The …

Asphaltene As Light Harvesting Material In Dye Sensitized Solar Cell, Rajab Emhemed Abujnah

Open Access Theses & Dissertations

This Dissertation characterizes the first asphaltene DSSC (dye-sensitized solar cell), in which light to electricity conversion efficiency has improved from 0 % to 1.8 %. Four natural organic asphaltene factions, namely, un-fractionated asphaltene, Fr. 1 Asphaltene, Fr.2 asphaltene, Fr.3 and Fr.4 were extracted and tested for various solar cell parameters of TiO2 based dye-sensitized solar cell DSSC. DSSCs were fabricated using the four individual asphaltene dyes. The photovoltaic performance of the cells was examined by determining the various parameters such as open-circuit voltage, short-circuit current, fill factor, and series resistance. The overall energy conversion efficiency was also measured to correlate …

Photocatalytic Destruction Of Halogenated Organic Compounds In Water With A New Photocatalyst, Mabruka Hadidan

Open Access Theses & Dissertations

In this research, a newly developed high surface area semiconductor porous material was synthesized from potassium titanium niobium mixed oxide (KTiNbO5) to be used as a photo catalyst in the presence of UV light to degrade halogenated organic compounds in water. The goal of the project was to investigate the catalytic activity of the material for its effectiveness in the degradation of the halogenated organic compounds, and it is the first investigation of this new photocatalyst with halogenated compounds. Model compounds dichloromethane, 1-chlorobutane, chlorobenzene, and trifluoroacetic acid in aqueous solutions were tested with the photocatalyst under ultraviolet light irradiation, using …

A Framework For Strategic Sustainable Supply Chain Design, Abril Paola Vazquez

Open Access Theses & Dissertations

Sustainable supply chain management has raised interest considerably in recent years; due to environmental concerns from society as well industries. There is a high interest in the industries to solve this problem but many of the frameworks are directed to specific situation or structure. A strategic sustainable supply chain design framework is presented with the purpose of providing many companies, including small and big industries, the means to maintain an eco-friendly operation. These include; industry plants, distribution centers, and retailers.