Digital Commons Network^™

Portraits Of Success: A Mixed-Method Study Of The Enrollment, Persistence, And Success Experiences Of Female Graduate Engineering Students At A Hispanic Serving Institution, Sandra Aguirre-Covarrubias

Open Access Theses & Dissertations

The current study addresses the underrepresentation of female graduate engineering students. Specifically, its purpose was to gain insight on how enrollment, persistence, and success factors are experienced by female graduate engineering students at a Hispanic Serving Institution located on the U.S.-Mexico border. The topic of underrepresentation of female graduate engineering students is important for higher education practitioners because in spite of the numerous attempts to increase their enrollment in science, technology, engineering and mathematics, their underrepresentation has persisted. The current study is modeled after research conducted by Cordova-Wentling and Camacho (2006). The research question that guides the current study is: …

Comparative Characterization Of Ni-Base Superalloys Fabricated By Laser And Electron Beam Melting Technologies, Krista Amato

Open Access Theses & Dissertations

Nickel-base superalloys have been used in cast and wrought, and powder metallurgy forms for nearly four decades for industrial and automotive applications. One drawback of cast alloys is that upon solidification, there is minimal microstructural control. Another issue to be improved is to eliminate the limitations of shapes and forms of fabricated alloys.

Rapid prototyping is a new technology of additive manufacturing that shows to be promising for the freeform fabrication of novel superalloys, including nickel-base alloys. New rapid manufacturing technologies allow us to produce parts in any shape that can be designed by computer-aided design (CAD) software. Additionally, the …

Substance Abuse And Rehabilitation: Understanding The Issue From First-Hand Accounts, Mauricio Enrique Austin

Open Access Theses & Dissertations

This study clarifies understanding of factors influencing substance abuse and rehabilitation from the perspective of the substance abuser. The data collection and analysis methods employed include single and cross-case analyses, based on data gathered through semi-structured, face-to-face life history interviews with thirteen individuals who had substance abuse histories. In some respects, study results coincide with the extant literature on the subject. For example, most study participants first used drugs and/or alcohol while they were children or adolescents; experienced family and/or peer influence to start using; suffered from illnesses and/or loss of employment in association with their substance abuse; experienced a …

Optimization Of Stress Wave-Based Nondestructive Methods In Identifying Deterioration In Concrete Structures, Hoda Azari

Open Access Theses & Dissertations

The transportation infrastructure across the United States is deteriorating and requires periodic inspection to predict the cost of repair and extent of maintenance activities, to remedy structural problems, and to ensure safety and serviceability. The use of nondestructive testing (NDT) methods in detecting and characterizing flaws in the infrastructure has become more common. Among different NDT methods, the stress wave-based methods, including ultrasonic surface waves (USW) and impact echo (IE) methods, are widely used to maintain concrete structures. In this dissertation, a complete literature review of seismic wave theory and wave propagation in plate like structures, and stress wave-based methods …

Operation New Dawn: Rhetoric Or Real Policy Change?, Josiah Thomas Barrett

Open Access Theses & Dissertations

Scholars have long explored questions concerning presidential foreign policy decision making as well as military performance in conducting operations. Studies have covered a wide variety of topics, including the organizational dynamics of the military bureaucracy, the effectiveness of military operations, how presidential rhetorical strategies influence the public agenda in foreign affairs, and, in turn, how public opinion influences presidential foreign policy decision-making. Despite these advances, there remains a notable gap in the literature with respect to the relationship between presidential foreign policy objectives and military bureaucratic responsiveness. In particular, when presidents use rhetoric to introduce key shifts in foreign policy …

Supply Chain Management: Impact Of Customer Relationship Marketing On Performance Under Cooperation And Competition Strategies, Maria Eugenia Barua

Open Access Theses & Dissertations

The dissertation investigation proposes a modified supply chain management model that is grounded on marketing theory and the concept of production sharing. Specifically, the model challenges the traditional cooperation-conflict continuum of strategic marketing management with a new managerial approach based on a cooperation-competition continuum. I investigate the significance of the new model in explaining behaviors in the supply chain management and its performance. In addition, I investigate whether the proposed managerial continuum (cooperation-competition) is consistent with other behaviors including power, conflict, trust, and customer relationship marketing such that coordination and supply chain performance is enhanced.

The data collection from manufacturers, …

Modeling The Human Gait Phases Using Granular Computing, Melaku Ayenew Bogale

Open Access Theses & Dissertations

Gait analysis is applied for the provision of diagnosis, evaluation, and for the design of therapeutic intervention for subjects suffering from neurological disorders. The benefits accruing from gait analysis are well established. People with neurological disorders like mild traumatic brain injury, Cerebral Palsy and Multiple Sclerosis, suffer associated functional gait problems. The symptoms and sign of these gait deficits are different from subject to subject and even for the same subject at different stage of the disease. Identifying these gait related abnormalities helps in the treatment planning and rehabilitation process.

The dynamic behavior of gait parameters is cyclic and the …

Size-Dependent Transitions In Grafted Polymer Brushes, Courtney Bosse

Open Access Theses & Dissertations

ABSTRACT

Finding probabilities in order to solve for the most likely configuration of a grafted polymer chain is easily calculated by solving a random walk problem, starting form a given point (the surface). A property of the random walk is used to describe the partition function of a polymer in terms of a sum over possible loops configurations, which simplifies tremendously the problem of calculating the partition function of the grafted polymer. Instead of solving the non-interacting random walk that has been well studied in the theory of the probability, the focus is on the problem of self-interacting random walks, …

A State-To-State Analysis Of Mexican Migration To The U.S., Avilia Bueno

Open Access Theses & Dissertations

The determinants of undocumented immigration flows from Mexican states to U.S. states utilizing data recently released by the Mexican consulate are analyzed. The impact of economic, demographic, and geographic factors on immigrant location choice in the year 2007 is analyzed using ordinary least squares, tobit, and two stage least squares to control for factors likely to be endogenous with immigration. The results generally support that immigrants tend to migrate towards states with higher Mexican immigrant populations, shorter distances, higher wages, and smaller populations. In addition, the relationship between undocumented immigration and economic freedom and the policy measures used to construct …

Thermal Barrier Coatings (Tbc's) For High Heat Flux Thrust Chambers, Christopher Michael Bradley

Open Access Theses & Dissertations

The last 30 years materials engineers have been under continual pressure to develop materials with a greater temperature potential or to produce configurations that can be effectively cooled or otherwise protected at elevated temperature conditions. Turbines and thrust chambers produce some of the harshest service conditions for materials which lead to the challenges engineers face in order to increase the efficiencies of current technologies due to the energy crisis that the world is facing. The key tasks for the future of gas turbines are to increase overall efficiencies to meet energy demands of a growing world population and reduce the …

Quark Fluctuations In A Chiral Model In The Presence Of A Magnetic Field, Lidens Cheng

Open Access Theses & Dissertations

Understanding the nature of the chiral and deconfinement phase transitions, the location of the critical point, and the properties in its vicinity are among the most important problems in the field of QCD. The purpose of this thesis is to use the two-flavor Nambu-Jona-Lasinio model in the presence of a magnetic field at the chiral limit to study the phase boundary where the spontaneously broken chiral symmetry is restored. At small chemical potential, the phase boundary exhibits a second-order phase transition. On the other hand, at large chemical potential and appropriate coupling constant, the phase boundary exhibits a first-order phase …

Three Essays Employing Cultural Value Theories To Explain Individual And National Differences In Ict Use/Adoption And Media Utilization Among Multiple Nations, Khendum Choden

Open Access Theses & Dissertations

This study investigates the impact of values on Information Communication Use/ adoption at an individual level and at the national level among advanced and emerging economies. We employ the use of Schwartz's individual values, Schwartz's cultural values and Hofstede's cultural values to empirically demonstrate its impact on multiple information communication technologies across advanced economies while controlling for demographics, GDP, income, and pronoun drop. We also study the moderating effects of culture on a variety of task characteristics and media use.

A Block Operator Splitting Method For Heterogeneous Multiscale Poroelasticity, Paul M. Delgado

Open Access Theses & Dissertations

Traditional models of poroelastic deformation in porous media assume relatively homogeneous material properties such that macroscopic constitutive relations lead to accurate results. Many realistic applications involve heterogeneous material properties whose oscillatory nature require multiscale methods to balance accuracy and efficiency in computation.

The current study develops a multiscale method for poroelastic deformation based on a fixed point iteration based operator splitting method and a heterogeneous multiscale method using finite volume and direct stiffness methods. To characterize the convergence

of the operator splitting method, we use a numerical root finding algorithm to determine a threshold surface in a non-dimensional parameter space …

Quantifying Carbon Allocation To Mycorrhizal Fungi By Temperate Forest Tree Species Across A Nitrogen Availability Gradient, Shersingh Joseph Tumber-Davila

Honors Theses and Capstones

Terrestrial ecosystems make up the largest carbon pool with a major portion of that being forests. With carbon being a major concern due to global climate change, being able to make accurate models is increasingly important. Studies have shown that trees may allocate up to 50% of their photosynthetically fixed carbon underground; however these values haven’t been accurately quantified and underground carbon allocation has been historically overlooked. Mycorrhizal fungi may be a large portion of underground carbon allocation, as they have a symbiotic relationship with trees where they provide the plant with water and nutrients in return for sugars (carbon). …

The Gray Kingbird (Tyrannus Dominicensis), Northern Florida To North Carolina, William Post

Florida Field Naturalist

No abstract provided.

Reddish Egret (Egretta Rufescens) Nesting In Clearwater Harbor And St. Joseph Sound, Pinellas County, And Crystal Bay, Citrus County, Florida From 1991 To 2011, Ann B. Hodgson, Ann F. Paul

Florida Field Naturalist

No abstract provided.

Rare Earth Element Geochemistry Of The Sierra Blanca Laccoliths, Texas, Amed Gomez

Open Access Theses & Dissertations

No abstract provided.

A Fashion Paradox: Reflective Thinking For Fashion Forecasting, Alyssa Dana Adomaitis

Publications and Research

No abstract provided.

Primary Drug And Multidrug Resistant Tuberculosis, Of The Diagnostic Properties Of The Sputum Smear Versus Culture Method For Tuberculosis Diagnosis In An Ecuadorian Urban Public Health Facility, Sandra Luz Groeschel

Open Access Theses & Dissertations

Background: The accurate diagnosis and effective prevention and control of tuberculosis (TB) are major global public health challenges. Ecuador has among the highest documented TB incidence (59/100,000 inhabitants) and mortality rates in the Americas region (27/100,000 inhabitants). In addition, TB multi-drug resistance is becoming increasingly common. The culture method is the preferred method of choice for diagnosing TB in the United States and many other high resource countries due to its high documented sensitivity. An added benefit of the methods is that it also can be used to detect primary TB resistance. In contrast, despite its lower diagnostic sensitivity, …

Reduced-Order Modeling Using Orthogonal And Bi-Orthogonal Wavelet Transforms, Miguel Hernandez Iv

Open Access Theses & Dissertations

It is well known that model reduction methods borrow techniques typically found in data compression, and current state-of-the-art techniques for data compression are based on the wavelet transform. Given these facts, it is surprising that model reduction using wavelets has not received much attention and has not been adequately addressed in the literature. This research seeks to determine if wavelets can be used for model reduction and if wavelet model reduction is a viable alternative to existing model reduction methods.

In this work we propose a novel method for model reduction using wavelets. Specifically, we introduce techniques for deriving wavelet …

Predictors Of Academic Success Between On-Track And Off-Track Students In A Mexican University, Jesus Francisco Hinojos

Open Access Theses & Dissertations

The main purpose of this study was to assess how predictors of quality of academic effort relate to academic success and student persistence of on-track and off-track students in a higher education institution in Northern Mexico; to investigate the relationship of pre-entry attributes,

family background and academic success as expressed by GPA among on-track, off-track and dropout students. And to examine the relationship between participants quality of effort invested in their own learning and development in six academic areas and four areas of college students' social activities.

This study utilized the College Student Experience Questionnaire (CSEQ) to determine the quality …

The Effect Of Co-Witness Information And Individual Differences In Cognitive Abilities On The Suggestibility Of Pre-School Children, Rachell Leanne Jones

Open Access Theses & Dissertations

Despite nearly 25 years of research, psychologists are still learning new ways in which various demographic, psychological, social, and cognitive factors contribute to child suggestibility. Numerous facets of each area have been studied independently, but as a field, it is becoming apparent that suggestibility is also affected by complex interactions between these various components (Scullin, Kanaya, & Ceci, 2002). The current study investigated several forensic interviewing techniques and psychosocial and cognitive factors that were hypothesized to influence child suggestibility. One hundred children were randomly assigned to five interview conditions after viewing a live event. The supposed statements of a co-witness …

Motivations For A Source To Resist An Interrogation: Consequences To The Self Versus Consequences To An Other, Julia Labianca

Open Access Theses & Dissertations

The current research investigated the effect of situational and dispositional factors on a source's decision to confess guilty knowledge of another's actions to an interrogator. The extant literature suggests that potential consequences to the self are a major motivator for decisions to confess or resist an interrogation. Previous research also suggests that the potential consequences to the other person may also influence a source's motivations to confess guilty knowledge. Additionally, personality measures related to interdependence versus personal independence (collectivism and individualism) and individual loyalty may also influence a source's motivations to cooperate with or resist an interrogation. However, few experiments …

Method Development For A Chemical And Biological Analysis Of Glucocorticoids In Wastewater, Maria Carmen Lozano

Open Access Theses & Dissertations

Glucocorticoids are a class of steroid hormones that can either be produced synthetically or naturally by the adrenal glands. The synthetic glucocorticoids are highly prescribed in the United States for their anti-inflammatory and immunosuppressive properties to treat a variety of ailments and diseases; however, these have been implicated in a number of adverse human conditions such as obesity, metabolic syndrome, immune-suppression, delayed puberty, adrenal insufficiency and Cushing Syndrome, among others. Ongoing research has shown that synthetic and natural hormones are transported to aquatic environments via mammalian excretion or wastewater effluent, and as a result, the release of glucocorticoids into the …

Complexity Of Affective Disposition And Reflective Transphenomenality: An Exploratory Study Of Middle School Mathematics Teacher And Student Self-Positioning And Positioning-By-Others Toward Mathematics, Mathematics Teaching, And Learning, Ruby Lorilee Lynch-Arroyo

Open Access Theses & Dissertations

The purpose of the mixed methods study was to examine the phenomenon of transphenomenal simultaneity between teacher and student disposition that contributed to the phenomenological conflict of teacher self-positioning and positioning-by-others toward mathematics, mathematics teaching and learning. The intent was to provide a view of self-reported and observed middle school teacher and student experiences in mathematics, based on the analysis of affective dispositional characteristics within the context of its complexity.

There is evidence that documents a relationship between teacher and student disposition, but to what extent and encompassing what characteristics and factors has not been sufficiently substantiated. Beyers (2011) identified …

In-Situ, Integrated U-Pb, Hf And O Isotopic Study Of Igneous, Metamorphic And Detrital Zircons. Implications To Crustal Evolution And Geodynamics, Munazzam Ali Mahar

Open Access Theses & Dissertations

Zircon data from South Karakoram gneiss dome provide evidence for Proterozoic inherited cores (1.8-1.9 Ga and 2.3-.2.5 Ga) surrounded by migmatitic overgrowth with ages ranging from ~6 to ~20Ma. Oxygen isotopic data of Neogene migmatite and inherited core is similar and indistinguishable ranging from 7.5 to 9.5 /. However, Neogene overgrowth is significantly less evolved than the inherited core in terms of Hf composition. This implies that the Hf composition of the migmatitic zircons is not controlled exclusively by the dissolution of the inherited cores and that contamination by external melts is likely. Isotopic data from the Baltoro plutonic unit …

Nanocomposite And Mechanically Alloyed Reactive Materials As Energetic Additives In Chemical Oxygen Generators, Marco Antonio Machado

Open Access Theses & Dissertations

Chemical oxygen generators are widely used for aircraft, spacecraft, submarines, and mine rescue. Oxygen-generating compositions typically include alkali metal chlorate or perchlorate that decomposes at increased temperatures, a transition-metal oxide as a decomposition catalyst, and a metal fuel that reacts with part of the produced oxygen to provide heat for a self-sustained propagation of the decomposition/combustion wave. To increase the oxygen yield per unit mass, it is of interest to minimize the amount of metal fuel, but decreasing its content leads to pulsating combustion and undesired fluctuations of the oxygen flow rate. This work explores the feasibility of replacing iron …

Endocrine Disrupting Compound 4-Nonylphenol And Neurodegeneration, Jessica Martinez Jurado

Open Access Theses & Dissertations

Neurodegeneration, a progressive loss of nerve cells (neurons), occurs in many neurological disorders including Alzheimer's disease, Parkinson's disease, Schizophrenia, and drug addiction. Cytoskeletal disruption in neurons and aggregation of proteins associated with these disorders is the hallmark of neurodegeneration. However, the cause of neurodegenerative disorders is unknown and currently there are no effective drug treatments. Aging is the most consistent risk factor for developing a neurodegenerative disorder, and recent evidence suggests that environmental factors, which act as endocrine disruptors, pose a risk in the disease process. 4- nonylphenol (4-NP), an endocrine-disrupting compound (EDC), has been shown to affect brain development …

Microstructure And Mechanical Properties Of Titanium Nitride Optical Coatings Made By Dc Magnetron Sputtering, Gustavo Martinez

Open Access Theses & Dissertations

Titanium nitride (TiNx) thin films were grown by DC (Direct Current) magnetron sputtering method onto Si(100) substrates by varying time of deposition to produce films with variable thickness (dTiN) in the range of 20-120 nm. The grown TiNx films were characterized by studying their structure, composition, and mechanical properties. Nuclear reaction analysis (NRA) combined with Rutherford backscattering spectrometry (RBS) analyses indicate that the grown films were stoichiometric TiN. Grazing incidence X-ray diffraction (GIXRD) measurements indicate that the texturing of the TiN films changes as a function of dTiN. The (111) and (002) peaks appear initially; with increasing dTiN, (111) becomes …

Cross-Border Mobility, Access To Healthcare Through Health Coverage, And Other Correlates For Utilization Of Healthcare Services Along The U.S.-Mexico Border, Krystal Martinez

Open Access Theses & Dissertations

BACKGROUND: At the national level, Hispanics suffer from poor health coverage. This is amplified in Texas, which has the highest percent (26.3%) of uninsured individuals in the U.S., and further augmented in El Paso, TX. In some border states and counties, barriers to healthcare include medically underserved areas, low-income, and the recent immigration among the Hispanic population. Cross-border mobility has facilitated access to health services in Mexico. Despite this, there remain gaps in understanding utilization of healthcare services among Hispanics in El Paso, TX. AIMS & OBJECTIVES: The aims of this study are to: (1) describe access to healthcare through …