Digital Commons Network^™

Gemini Metallo-Surfactants: Chemical And Physical Properties, Erich Ivan Valenzuela

Open Access Theses & Dissertations

Gemini surfactants are amphiphilic molecules that consist of two surfactant molecules chemically joined together by a spacer group. These molecules tend to self‐assemble into vesicles at much lower concentrations than traditional surfactants and have found many applications in catalysis, adsorption applications, drug‐delivery, nanoscale technology, and biotechnology. In this thesis, the synthesis, characterization and physical properties of a new type of Gemini surfactant derived from dinuclear Cu(II) metal complexes is presented. We call these molecules Gemini Metal‐Organic Surfactants (GMOs).

Three newly developed new GMOs (compounds 1‐3) are composed of Cu(II) ions ligated to a lipid‐functionalized triamine group and the metals are …

X-Ray Diffraction Studies Of Room And Intermediate Tempertaure Phases Of Phosphate Based Solid Acids, Kiran Vajrapu

Open Access Theses & Dissertations

In this work, the MH2PO4-type solid acids (where M= Cs, K, Rb) structure and properties are studied and their contribution towards fuel cell industry is understood. Some research groups have shown that, CsH2PO4 (CDP) and RbH2PO4 (RDP) shows sudden, several order of magnitude jumps in their proton conductivity at certain high temperatures.(31, 32) This so called superprotonic behavior of these compounds makes them a fuel cell electrolyte at elevated temperatures. (33) Most of the research groups working on two possible causes to get the reliable information for the high proton conductivity: polymorphic phase transition (Botez et al.,) and thermal dehydration …

Indentifying And Understanding User Preferences In Generic Planning Tools, Grisel Ventura

Open Access Theses & Dissertations

Planning is an important cognitive work activity. To support this complex task, the development of planning tools is important to support people during decision-making and problem-solving tasks. Nowadays, a large number of manual and electronic tools support this complex activity; manual and electronic planning tools aid people in creating strategies for effective work performance. However, there is limited information on the design of generic planning tools people use for their activities, and why people choose to use the planning tool they do. Some examples of generic tools for planning are calendars, checklists, agendas, etc.

To answer this question, this research …

Evaluating Suspended Dust Particulate Matter From Anthropogenically - Altered Lands, Roberto Velarde

Open Access Theses & Dissertations

Substantial dust loads are transported from drylands including the Saharan, Asian, and Chihuahuan Desert deposits by localized to planetary-scale processes to nearby and distal sites. These dusts may carry harmful constituents. To evaluate dust movement patterns and characteristics relative to carried constituents, three studies are presented comprising (A) Localized displacement of uranium and progeny radionuclides from high-grade uranium ore storage piles at Peña Blanca, Chihuahua, Mexico; (B) Long-distance transport of plutonium via Saharan and Asian aeolian pathways; and (C) Dust movement patterns in military maneuvering and non-maneuvering areas at White Sands Missile Range (WSMR), New Mexico. Study (A) evaluated surface …

Transferability Of Child Labor Norms: Examining The Link Between Foreign Direct Investment And Child Labor Practices In Developing Countries, Ijtsuri Anayantzin Viveros

Open Access Theses & Dissertations

Why do child labor norms often fail to be transferred or enforced in developing countries even if the implementation of such norms already proved to have substantially reduced child labor practices in developed regions? In the field of international political economy, a number of studies examine how international trade in general and foreign direct investment (FDI, hereafter) in particular influence economic growth, income equality, and balance of trade in developed and developing countries. Extending the literature on international trade and investment, this thesis examines the relationship between FDI and child labor practices in developing countries.

Specifically, I investigate whether and …

Distributional Properties Of Inversions And Segmentation Algorithms For Rna Sequences, Sameera Dhananjaya Viswakula

Open Access Theses & Dissertations

Ribonucleic acid (RNA) is a long single stranded molecule made up of four types of nucleotide bases: Adenine (A), Cytosine(C), Guanine (G) and Uracil (U). It folds back on itself and forms C-G and A-U complementary base pairs. The set of such hydrogen-bonded pairs in an RNA molecule is called its secondary structure. Knowing the secondary structure of RNA is useful for understanding its biological function. Prediction of RNA secondary structure from the nucleotide sequence has been an important bioinformatics problem for over two decades.

The work in this thesis is motivated by the need to improve the secondary structure …

Principles Of Thomas Pynchon's Literary Realities, Ira Anthony Walker

Open Access Theses & Dissertations

Thomas Pynchon's literature is unique in subject and style. Postmodern by definition, Pynchon illustrates physics as a societal metaphor; Guy Debord's text The Society of the Spectacle suggests that these societal, literary, metaphors constitute and/or lead to a Spectacle. Through the analysis of an unpublished text: Minstrel Island, an early written short story: "Entropy," and a short novel: The Crying of Lot 49 the reader is capable of seeing a developing theme of physics as metaphor constituting multiple Spectacles. The narrative devices offered by Thomas Pynchon become Spectacular in nature and reflect the characteristics and environment of the tumultuous 1960s …

Strategies To Improve And Preserve Flexible Pavements At Intersections, Imad N. Abdallah

Open Access Theses & Dissertations

Many rural intersections originally constructed with thin untreated flexible base and hot mix or a two-course surface treatment experience severe pushing, shoving and rutting. These failures cause an extremely rough surface that can cause damage to small vehicles and potentially cause motorists to lose control of their vehicle. These distresses almost always result in complete failure of the existing pavement that must be repaired several times during the life of the roadway by maintenance forces. Pavement sections constructed with the same materials adjacent to the intersection perform adequately until the approach (approximately 150 ft in advance) of the intersection and …

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 …

Novel Photovoltaic Device For Targeted Drug Delivery, Sunny S. Ambure

Open Access Theses & Dissertations

Despite decades of research, progress in targeted drug delivery is relatively slow, hampered, in part, by the lack of appropriate mechanisms to deliver anticancer drugs selectively to tumor tissues. Systemic or oral administration can cause severe toxicity, which limits the therapeutic potential of anticancer drugs [1]. Therefore, the most important goal of drug delivery is to minimize the exposure of normal tissues to these drugs while maintaining their therapeutic concentration in tumors.

A photovoltaic cell (PV) is a system that converts lights into electricity as well as induces charge transfer by photovoltaic effect. Motivated by such unique property, we have …

Smaller Learning Communities And Student Performance At The High School Level, Christopher Edward Avila

Open Access Theses & Dissertations

The purpose of this study was to compare the performance of students who participated in a traditional high school curriculum with those exposed to smaller learning communities or academies within traditional high schools. As a type of school reform, the district, located in a southwestern school district that was the focus of this study, implemented within seven different high schools smaller learning communities in the areas of business, technology, medicine, math, science, and communications. A large percentage of the student population (approximately 83% Hispanic, 14% Caucasian, and 3% Black) is from the lowest socioeconomic group as defined by federal guidelines …

Communicative Practices That Lead To Timely High School Graduation Against All Odds: A Positive Deviance Inquiry In A Predominantly Hispanic School, Patricia Teresa A

Open Access Theses & Dissertations

The school dropout rate among Hispanics is a major financial, educational, and public concern in the United States. However, some school districts that primarily enroll Hispanic students are succeeding in retaining and graduating their students against all odds, utilizing resources already present within their community. These institutions are "positive deviants" - they are "deviants" because they are not the norm and "positive" because they embody desirable outcomes. In such high schools are enrolled students, who against all odds, work their way to timely graduation. They are positive deviants within their institution. The present study conducted in a U.S.-Mexico border city …

An Ultra Low Power Subthreshold Delta Sigma Digital To Analog Converter, Ricardo Baca

Open Access Theses & Dissertations

Abstract

In the last four decades the incorporation of analog, digital and mixed-signal integrated circuits (IC) using Complementary Metal Oxide Semiconductor (CMOS) technology has been dramatically increasing and is improving almost every aspect of modern life. Furthermore, the continuous advances in CMOS Very Large System Integration (VLSI) technology allow higher integration densities and the increasing number of subsystems in a single chip results in higher speed execution and lower power consumption. Therefore, the increasing digitalization in electronic circuits across a wide range of battery-operated applications where reliability and power dissipation are critical requires Digital to Analog Converters (DACs) with higher …

Magnetic-Field Induced Stability In Two-Flavor Color Superconductivity, Churna B. Bhandari

Open Access Theses & Dissertations

It has long been understood that the ground state of a superdense quark system, a Fermi liquid of weakly interacting quarks, is unstable with respect to the formation of diquark condensates. This nonperturbative phenomenon is essentially equivalent to the Cooper instability of conventional BCS superconductivity. As the quark pairs have nonzero color charge, this kind of superconductivity breaks the SU(3) color gauge symmetry, thus it is called color superconductivity. A peculiar feature of spin-zero color superconductivity is the lack of Meissner effect for a combination of the regular electromagnetic field and one of the gluon fields. This combination behaves as …

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 …

The Effects Of Tai Chi On Balance And Peripheral Somatosensation In Older Adults With Type 2 Diabetes, Elisabeth Inge Cavegn

Open Access Theses & Dissertations

The increasing prevalence of type 2 diabetes in older adults is a major health concern, as older adults with diabetes have a two- to threefold risk of injurious falls and physical disability. Although studies on the effects of Tai Chi on balance and fall prevention have increased over the last two decades, the benefits for older adults with diabetes, specifically for those with impaired somatosensation in the lower extremities, are limited. Therefore, the purpose of this study was to investigate the effects of Tai Chi exercise on balance, peripheral somatosensation, and fitness in older adults with type 2 diabetes. The …

Collaborative And Distributed Algorithms For Localization In Wireless Sensor Networks Based On The Solution Of Spatially Constrained Local And Sub-Local Problems, Juan De Dios Cota

Open Access Theses & Dissertations

In this research we present algorithms for the distributed and collaborative localization of nodes for applications in wireless sensor networks. The algorithms are distributed in the sense that each node can estimate its own position using only range information and position estimates from neighboring nodes. The algorithms aim at achieving good accuracy with low computational complexity and low energy consumption. We consider the full localization process consisting of an initialization stage followed by a refinement stage.

For initialization, we propose a \emph{bilateration} algorithm where each node uses a set of anchors and their respective ranges to solve a set of …

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 …

Analysis Of Endocrine Disrupting Compounds In Wastewater Treatment Plants: A Perspective Of Trans-Boundary Waterborne Pollution, Roberto De La Torre

Open Access Theses & Dissertations

Recent decades have brought an increasing concern of potential adverse human and ecological health effects resulting from Endocrine Disruptor Compounds (EDCs). In particular from new emerging compounds such as natural estrogens (e.g., 17©¬-estradiol, estrone), synthetic estrogens (e.g., 17Â¥á-ethynylestradiol), bisphenol A (BPA), nonylphenol ethoxylates (NPEOS), and nonylphenol (NP). These chemicals which are also known as organic wastewater contaminants are released directly to the environment after passing through wastewater treatment plants (WWTPs), which often are not designed to remove them from the effluent. The occurrence of the aforementioned compounds in surface water is becoming of increasing concern worldwide, and has led to …

Incorporating Sustainability Into Urban Infrastructures: The Tension Between Bio-Cultural Aspects And Environmental Considerations, Shane Epting

Open Access Theses & Dissertations

The following arguments focus on how to think about sustainability as it relates to technology and the non-human world within an anthropocentric framework. We end up with a picture showing that humankind needs to change the ways in which we look at anthropocentric concerns. Secondly, the discussion that leads up to the final picture details the urgency that guides the thinking behind the implementation of sustainability. Because, as the West learns to live in an entirely new sense that is consistent with holding humankind's desire for existence as a permanent situation, one finds that this notion must be paramount for …

An Analysis Of The Zone Of Proximal Development As A Practicable Learning Theory Of Organizational Culture In The Workplace, Patricia Ann Gonzalez

Open Access Theses & Dissertations

This study analyzes and tests Lev Vygotsky's theory of the Zone of Proximal Development (ZPD) as a practicable learning model of organizational culture in the workplace. The ZPD poses a possible clarifying theory of the individual internalization of organizational culture in the workplace that enhances current theories of organizational assimilation and learning. Qualitative methods were quantified to test this theory using five categories of organizational culture and a 4-stage model created by Roland Tharp and Ronald Gallimore presented in their book Rousing Minds to Life (1988) to organize a 30-question survey that was administered to a representative sample of employees …

Swimming In Static, Sahalie Saecker Hashim

Open Access Theses & Dissertations

In this novel, two young adults exist simultaneously in separate worlds. Torn apart by perception, culture, and socioeconomic differences, these individuals come to learn what it means to see the world, and understand one another through extraordinary experiences.

Child Development And Child Rearing In Ciudad Juárez, México Colonias: Economic, Social, And Cutural, Alma Angelica Hernandez

Open Access Theses & Dissertations

Supporting the development of healthy children is a goal for parents. Proper development becomes a challenge when children do not receive adequate health care, educational enrichment, and housing. These challenges are amplified by the continuous rise in violence in the U.S.- México border region. This study looks specifically at child development and child rearing practices in two poor colonias (neighborhoods) in Ciudad Juárez (Chihuahua, México). It relies on and extends from a project conducted by Gente a favor de gente and funded by the Paso del Norte Health Foundation. There were 2 phases in this study: a quantitative phase (N=151) …

A Third-Order Non-Oscillatory Finite-Volume Transport Scheme For Atmospheric Modeling, Kiran Kumar Katta

Open Access Theses & Dissertations

Atmospheric numerical modeling has been going through drastic changes over the past decade, mainly to utilize the massive computing capability of the petascale systems. This obliges the modelers to develop grid systems and numerical algorithms that facilitate exceptional level of scalability on these systems. The numerical algorithms that can address these challenges should have the local properties such as the high on-processor operation count and minimum parallel communication i.e. high parallel efficiency, it should also satisfy the following properties such as inherent local and global conservation, high-order accuracy, geometric flexibility, non-oscillatory advection, positivity preservation.

In the present work, A Third-order …

Segundo Barrio: Rich, Poor, Or Both?, Julie Anne Krill

Open Access Theses & Dissertations

ABSTRACT

This manuscript describes an exploratory study which was undertaken in Segundo Barrio; a historic neighborhood in El Paso, Texas. The purpose of the study was to identify formal and informal sources of social support through the perceptions of female residents in different stages of life. This community, while economically disadvantaged, has unique characteristics and resources and the researcher was interested in seeing how different age groups perceive them.

Guiding Research Questions:

What sources of social support do residents of Segundo Barrio identify as key sources of support within their neighborhood, Greater El Paso, and Ciudad Juarez, Chihuahua?

* Social …

Responding To Haiti's Earthquake: Volunteer Health And Community Relationships, Mary Nelan

Open Access Theses & Dissertations

Disaster volunteers are an important group of workers on the ground after a disaster. International volunteers have not been the subject of much research in the past. Following the January 12, 2010 earthquake in Haiti, an American-based NGO set up a base in Leogane, the epicenter of the earthquake. The purpose of this research is to further understand the disaster volunteer population and help inform international NGOs who respond to disasters. This thesis focuses on the volunteers who worked with that organization during 2010. As a volunteer, I witnessed the situations that inspired this research through my own experiences for …

Conformal Electronics Packaging Through Additive Manufacturing And Micro-Dispensing, Richard I. Olivas

Open Access Theses & Dissertations

Realizing electronic systems that are conformal with curved or complex surfaces is difficult if not impossible with conventional fabrication techniques, which require rigid, two dimensional, printed circuit boards (PCB). Flexible copper based fabrication is widely available commercially providing conformance, but not simultaneously stiffness. As a result, these systems are susceptible to reliability problems if repeatedly bent or stretched. The integration of Additive Manufacturing (AM) combined with Direct Print (DP) micro-dispensing can produce shapes of arbitrary and complex form that also allows for 1) miniature cavities for insetting electronic components and 2) conductive traces for electrical interconnect between components. The fabrication …

What Motivates Females To Participate In Collegiate Level Sports?, Laura Abril Pacheco

Open Access Theses & Dissertations

Despite the many health benefits, physical activity trends in females have been previously reported to be lower than males. The purpose of this study is to explore the motivational influences that engage college females to participate in sports. This was a cross sectional, causal-comparative survey study that included mixed methods of data collection. 82 female college athletes from two post-secondary institutions responded to a 35 item Modified Sports Motivation Survey and 7 participants volunteered to be in a focus group discussion. Motivational factors examined were fitness, skill/mastery, fun/excitement, affiliation/recognition, team factors, ego/competition, parental support, and external rewards. Quantitative analysis revealed …

Assessment Of Intra-Urban Traffic-Related Air Pollution On Asthmatic Children's Exposure At Schools In The Paso Del Norte Region, Amit Ugamraj Raysoni

Open Access Theses & Dissertations

Traffic-related air pollution can be a major public health concern in any urban area. This problem is compounded in the Paso del Norte region that has experienced rapid economic growth, and a substantial number of people living in close vicinity of major roadways. The desert surroundings, arid weather, frequent temperature inversions, heavy border traffic at the international ports of entry between El Paso and Ciudad Juárez, and poorly maintained vehicle fleet further exacerbates this problem. A growing body of air quality and epidemiologic research has discerned the linkage between traffic emissions and respiratory disorders.

Initial health investigations in the Paso …

The Exploratory Value Of Agent-Based Models In Social Science, Ricardo Andress Rivera

Open Access Theses & Dissertations

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