Physical Sciences and Mathematics Commons^™

Growing Cities Depend On Ecosystem Services, David E. Ervin, Darrell Brown, Heejun Chang, Veronica Dujon, Elise F. Granek, Vivek Shandas, J. Alan Yeakley

Geography Faculty Publications and Presentations

Many studies have documented the growing fragility of a majority of the globe's ecosystems. Policymakers and resource managers often frame such ecosystem challenges as primarily about protecting natural systems in rural areas. However, that conception misses a key part of the story: the rapid growth of urbanizing areas. Home to more than 50 percent of the world's human population for the first time in modern history, urbanizing regions concentrate pressure on ecosystem services, which are necessary to sustain healthy urban living conditions and vibrant commerce. This dramatic urbanization presents both challenges and opportunities for novel ecosystem services management. A transdisciplinary …

Development Of The Control And Ignition Systems On A High Pressure Gas Turbine Combustor, Carlos Alejandro Valdez

Open Access Theses & Dissertations

The ignition and control systems of a laboratory scale high-pressure gas turbine combustor were developed in the present work. This work provides a detailed description of the design, development and testing of the remote control system developed for a High Pressure Gas Turbine Combustor (HPTC).

The combustor has the capability to operate at pressures up to 1.5 MPa and temperatures up to 2400 K. It is also designed for a maximum air and fuel flow rates of 81.93 g/s and 35.77 g/s respectively. The fuel used will be CH4 for the early experiments but it is designed to operate using …

New Multi-Objective Evolutionary Game Theory Algorithm For Border Security, Franciso Oswaldo Aguirre

Open Access Theses & Dissertations

The complexity of border security relays on the diversity and volume of illegal activity that must be controlled, and the variety of resources that can be deployed to secure the border. A key operational problem encountered by those charged with the task of border security is the scheduling and deployment of patrols. Patrolling can be defined as the act of walking or traveling around an area - network-, at regular intervals, in order to protect or supervise it. The problem of optimizing schedules for patrolling open areas is one that arises in many contexts, and has attracted significant attention from …

Microelement Localization In Leaves Of Populus Spp. And Tolerance Mechanisms To Boron-Salt Toxicity, Daniel Arriaga

Open Access Theses & Dissertations

Phytoremediation has been proposed as a low-cost, environmentally friendly alternative to clean highly contaminated sites. Phytoremediation using trees offer the advantage of metal immobilization (phytostabilization), high hydraulic pumping pressures, produce large plant biomass, absorption of total dissolved salts within their tissue, long life spans, less frequent irrigation and, a massive root system that helps soil attachment. Hybrid poplar varieties are long-lived, perennial, fast growing, and produce a large amount of foliage to harvest. Boron is an essential micronutrient for plants. Certain locations, such as California and Turkey, have suffered from high boron efflux from irrigation waters. It has been identified …

Granular Computing For Assessment Of Mild Traumatic Brain Injury, Melaku Ayenew Bogale

Open Access Theses & Dissertations

Mild traumatic brain injury (mTBI) is one of the most common neurological disorders. It is a serious public health problem in the United States. Although, penetrating (open) brain injuries that result in extended period of loss of consciousness (LOC) usually gets attention and well taken care of by the emergency departments, mild traumatic brain injury with no visible sign of damage, may be undetected or misdiagnosed. The clinical assessments and evaluations are mostly based on subjective cognitive and behavioral tests. Many people after suffering mTBI complain about decreased balance, coordination and stability even though the clinical evaluations show no sign …

Confirmation And Investigation Of Higher Science Curiosity In Juarez Middle School Students Compared To Their Peers In El Paso, Texas, Karla Carmona Miranda

Open Access Theses & Dissertations

In the last 20 years attitudes towards science and science classes in K-12 education have been an important topic of investigation due to the decreasing number of students choosing Science, Technology, Engineering and Math (STEM) related careers, and the increasing need for STEM prepared workers to cover the job demands of the future. The purpose of this study is to confirm a previously measured difference in scientific curiosity between middle school students in El Paso and in Ciudad Juarez, and to collect additional data that might tell us what the possible factors or reasons for this difference are. Our sample …

Dynamic Earthquake Triggering In The Continental U.S., Ibrahim Cerda

Open Access Theses & Dissertations

Seismological studies have classified the changes in field stress required to trigger remote earthquakes into two basic types: static and dynamic triggering. Static triggering mainly originates from geological faults already present in certain tectonic environments and they could be originated due to continental crust, subduction zones or even from a highly seismicity zone. Dynamic triggering occurs when an event (earthquake) has been induced by the passing of seismic waves from a large main shock located at least two or more fault lengths from the epicenter of the main shock. This study investigates details of dynamic triggering not seen in previous …

Sustainable Wastewater Management For Paso Del Norte Border Communities, Mariana Chew

Open Access Theses & Dissertations

At the binational level, there is no enforceable formal or informal agreement for approval of a water or wastewater discharge from the United States or Mexico. The communities along the U.S.-Mexico border are included in the cooperative activities of: (1) U.S. Environmental Protection Agency (EPA) Region VI, (2) Mexico Secretarí­a de Medio Ambiente y Recursos Naturales (SEMARNAT), (3) the binational Border Environment Cooperation Commission (BECC) and Comisión de Cooperación Ecológica Fronteriza (COCEF), (4) the binational North American Development Bank (NADBANK) and Banco de Desarrollo de América del Norte (BDAN), and (5) the binational International Boundary and Water Commission (IBWC) and …

Stereo Matching - Improving Image Quality, Aritra Dattagupta

Open Access Theses & Dissertations

Stereo vision or stereopsis is a biological process in which the impression of the depth of a scene viewed by the two eyes is perceived. Stereo vision helps us to see where objects are in relation to our bodies. Computational stereo describes the process of synthesizing the mechanics of binocular vision; and stereo matching is an important process in the problem of computational stereo.

Stereo matching is used for Digital Elevation Modeling (DEM), which is the method of extracting 3D information from digital images obtained by cameras and, therefore, is a crucial process for representing a 3D view of surfaces …

Generalized Linear Latent Mixed Modeling Of Functional Independent Measures And Patient Outcomes, Maduranga Kasun Dassanayake

Open Access Theses & Dissertations

The Functional Independent Measure (FIM) is one of the most widely accepted functional assessment measures used in the rehabilitation community. Past research studies have investigated the relationship between place of discharge, admission FIM scores or FIM difference scores, and patients' characteristics and found relationships between those variables. However, most of these studies fail to account for the multi-layered multidimensionality of the FIM and the measurement error associated with the FIM items. This study utilizes Generalized Linear Latent Mixed Models (GLLAMM) and Structural Equation Models (SEM) to assess which patient characteristics are associated with FIM difference scores and the structural relationship …

Raman And Infrared Study Of Electrospun Plla/Pcl Nanofiber Blends For Use In Tissue Engineering, Jose Luis Enriquez Carrejo

Open Access Theses & Dissertations

Recently, the biomedical engineering field has developed at a very fast pace as improved techniques and materials become available to promote its growth. Consequently, the research in polymeric biomaterials has been highly stimulated by this trend. The goal of the current research is to demonstrate the usefulness of the Raman scattering, Raman mapping, and infrared absorption spectroscopies to tissue engineering, by spectroscopically characterizing blends of PLLA and PCL polymers, which were prepared by electrospinning with and without cell addition. The proposed use of these blends is as primary biomaterials in biodegradable scaffolds used in tissue engineering. Both Raman and infrared …

Structural Analysis Of The Central Ibex Hills, Death Valley, California, Oscar Esparza

Open Access Theses & Dissertations

The Ibex Hills, in southern Death Valley, California, are composed mainly of Late Proterozoic sedimentary rocks overlying middle Proterozoic basement that are complexly deformed by Mesozoic contractional structures overprinted by Neogene extensional/transtensional structures. Detail mapping of the Ibex Hills reveals evidence of several deformational events. Brittle deformation of both extensional and strike-slip origin are recognized throughout the mapped area, but the main structure identified is a low angle fault at the base of the Noonday Dolomite, Sentinel Peak member, herein called the Noonday Fault. This low angle fault is dipping toward the east-northeast and has a curved geometry that resembles …

Dihedral Cayley Directed Strongly Regular Graphs, Jose Jonathan Gamez

Open Access Theses & Dissertations

A graph is a directed strongly regular graph (DSRG) if and only if the number of paths of length 2 from x to y is: λ, if there is an edge from x to y; μ, if there is not an edge from x to y (with x not equal to y); and t, if x = y. For every vertex in G, the in-degree and out-degree is k. The number of vertices in G is denoted by v. If G is a group and S a subset of G, then the …

The Impact Of Solar Radiation On The Distribution Of The Red Imported Fire Ant, Solenopsis Invicta (Hymenoptera: Formicidae), Audrey Marie Hernando

Open Access Theses & Dissertations

This dissertation investigates the role of solar radiation on Solenopsis invicta, the red imported fire ant. This ant is considered a serious invasive pest in the southern United States. Four Texas cities where fire ants are found were studied: San Antonio, Corpus Christi, Wichita Falls, and the outlier, Lubbock. Shade angles were measured in eight compass directions within plots located along eight transect directions around buildings. Using the shade angle, solar radiation for different times of day and seasons were calculated. All of the cities were on the same precipitation isocline with the exception of Lubbock, Texas. The number of …

Disparities In Park Availability, Features, And Characteristics By Social Determinants Of Health Within A U.S.-Mexico Border Urban Area, Amir Kamel

Open Access Theses & Dissertations

Background: Parks have been shown to be a key feature in the built environment that promote physical activity and positively influence health. However, a number of studies have highlighted that park availability, park features (e.g., park facilities, amenities, and aesthetic features), and park characteristics (e.g., quality/safety concerns of the park and surrounding neighborhood) are not equally distributed across neighborhoods in the U.S, specifically areas of low socioeconomic status and diverse racial/ethnic composition. The overall aim of this study was to examine and describe park availability, park features, and park characteristics, and determine their association with two social determinants of health …

Electrical Characterization Of Microcrystalline Lifepo4 For Application In Lithium Ion Batteries, Sukhdeep Amarjeet Labana

Open Access Theses & Dissertations

Electrical Characterization of Microcrystalline LiFePO4 for application in lithium ion batteries. Mainly, to study about the electrical properties of Lithium Iron Phosphate as a cathode material to increase its Electrical consumption.

The Impact Of Decadal Land Cover Change On The Global Warming Potential Of Beringian Arctic Tundra, David Hwei-Len Lin

Open Access Theses & Dissertations

Arctic terrestrial ecosystems play an important role in the global carbon cycle. If arctic warming continues to rise as projected, large amounts of soil carbon stored in these ecosystems could be released to the atmosphere as carbon dioxide or methane and positively enhance greenhouse warming. Thus, improving understanding of the likely future state and fate of arctic soil carbon, and the carbon uptake potential of arctic terrestrial ecosystems are well recognized research priorities.

At the pan-arctic scale, decadal increases in NDVI (Normalized Difference Vegetation Index), an index of vegetation productivity, have been observed from satellite imagery, indicating a general greening …

A Survey Of Selected Pharmaceuticals And Personal Care Products In A Binational River And Their Effects On A Member Of Its Zooplankton Community, Plationus Patulus (Rotifera), Diana Angelica Martinez Gomez

Open Access Theses & Dissertations

The presence of 9 selected PPCPs (acetaminophen, caffeine, cotinine, codeine, fluoxetine, erythromycin, ciprofloxacin, sulfamethazine, and trimethoprim) was surveyed in water samples collected at four sites along the middle Rio Grande during two flow regimes (irrigation and non-irrigation). Water collection for PPCPs analyses were conducted from August 2010 through September 2011. Three of the sites were located upstream, in, and downstream of the El Paso, TX/Ciudad Juárez, MX metroplex. Site selection was based on their proximity to the metroplex and due to the fact that the Rio Grande in this region is an effluent receiver water system (IBWC, 2011). The fourth …

Lacking A Connection To A Community Water System: Water Quality And Human Health Impacts In El Paso Colonias, Yolanda Jane Mcdonald

Open Access Theses & Dissertations

Water-borne disease and its symptoms, such as stomach cramps and diarrhea, are a serious concern in areas that are not connected to a public water system. To investigate the impacts of not being connected to a community water system, I surveyed households in El Paso County colonias that were not connected to a community water system (household n = 75, individual n= 293) and households that were connected to a community water system (household n = 75, individual n= 320). I conducted 150 door-to-door surveys and tested water samples from each household for free residual chlorine level, turbidity level, presence …

Algorithmic Aspects Of Analysis, Prediction, And Control In Science And Engineering: Symmetry-Based Approach, Jaime Nava

Open Access Theses & Dissertations

Algorithms are extremely important in science and engineering. One of the main objectives of science is to predict future events; this usually requires sophisticated algorithms. Once we are able to predict future events, a natural next step is to influence these events, i.e., to control the corresponding systems; control also usually requires complex algorithms. To be able to predict and control a system, we need to have a good description of this system, so that we can use this description to analyze the system's behavior and extract the desired prediction and control algorithms from this analysis. A typical prediction is …

Numerical Modeling Of Tectonics And Fault Activity Of Icy Satellites, John Olgin

Open Access Theses & Dissertations

Enceladus, one of the satellites of Saturn, exhibits evidence of recent fault activity, which may be due to gravitational fluctuations, or tidal stresses, generated by its orbit around Saturn. Recent Cassini spacecraft observations of Enceladus reveal water-ice plume activity at the south polar region, originating from locations that correlate with four geologically young, linear fracture-like features, named the "tiger stripes". It is the goal of this investigation to determine the ideal geophysical and geological factors (e.g., fault depths, frictional coefficients, ice layer thickness, ocean layer thickness, tidal stress sources) that support fault activity on Enceladus. The core of this work …

Sensitivity Analysis Of Streambed Leakance Downstream Of Caballo Reservoir, Derrick Ohara

Open Access Theses & Dissertations

Modeling transient effects of streams near well fields is an important tool for understanding water balance within the Rio Grande Project (Project). The results are known as stream leakage. Stream leakage quantifies the amount of water seeping from a stream, canal and/or drain to/from a well field. Stream leakages near the Canutillo Well field, primary river losses for years 2005 through 2010 along with historical gain/losses and allocations of surface water with the associated agreements were evaluated.

The overall loss rates per mile in the Project for years 2005 to 2010 averaged -0.75 cubic feet per second (cfs). The historical …

Low Energy Disruption Of Lipid Containing Biomass, Joaquin Rodriguez

Open Access Theses & Dissertations

Lipid containing biomass from microalgae has received recent research interest as a renewable and sustainable feedstock for biofuel production. Algae is known to offer as much as 30 times the energy density than corn based ethanol, the current world standard for biomass based liquid transportation fuels. The development of large scale systems and methods of extracting lipids from microalgae is still in the early stages of development and significant increases in efficiency and reduction in costs are necessary to substantiate algae as a feasible alternative source of fuel. Traditional conversion of algae feedstock into a refineable feedstock for biofuel can …

Propagation Of Interval And Probabilistic Uncertainty In Cyberinfrastructure-Related Data Processing And Data Fusion, Christian Servin

Open Access Theses & Dissertations

Data uncertainty affects the results of data processing. So, it is necessary to find out how the data uncertainty propagates into the uncertainty of the results of data processing.

This problem is especially important when cyberinfrastructure enables us to process large amounts of heterogeneous data.

In the ideal world, we should have an accurate description of data

uncertainty, and well-justified efficient algorithms to propagate this uncertainty. In practice, we are often not yet in this ideal situation:

the description of uncertainty is often only approximate, and the algorithms for uncertainty propagation are often not well-justified and not very computationally efficient. …

Isotope Geochemistry And Geochronology Of Lavas From The Line Islands Chain, Central Pacific Basin: Insight Into The Origin Of The Line Islands, Lauren Storm

Open Access Theses & Dissertations

Geochemical compositions of melts produced in the Earth's mantle provide key data for understanding Earth's internal structure. Particularly, the compositions of unusually large outpourings of basaltic lavas in large igneous provinces involve substantial source volumes, thereby contributing to our understanding of mantle structure and dynamics. Although the origin of such lavas remains enigmatic, geochemically they may originate from Earth's oldest and deepest mantle reservoir, transported by a mantle plume or by entrainment in passive upwelling beneath a fast spreading center. The Pacific Ocean basin hosts several large igneous provinces that formed near a triple junction of three oceanic plates, and …

Partial Orders For Representing Uncertainty, Causality And Decision Making: General Properties, Operations, And Algorithms, Francisco Adolfo Zapata

Open Access Theses & Dissertations

One of the main objectives of science and engineering is to help people select the most beneficial decisions. To make these decisions, we must know people's preferences, we must have the information about different possible consequences of different decisions. Since information is never absolutely accurate and precise, we must also have information about the degree of certainty of different parts on information. All these types of information naturally lead to partial orders:

- For preferences, a <= b means that b is preferable to a. This relation is used in decision theory.

- For events, a <= b means that a can influence b. This causality relation is one of the fundamental notions of physics, especially of physics of space-time.

* For uncertain statements, a <= b means that a is less certain than b. This relation is used in logics describing uncertainty, such as fuzzy logic.

In each of these areas, there is abundant research about studying the corresponding partial orders. …

Biological Effects Of Copper On Prosopis Pubescens (Screw Bean Mesquite), Marian Nicte Zappala

Open Access Theses & Dissertations

Phytoremediation is an emerging technology for cleaning industrial and urban contamination (Peuke and Rennenberg, 2005). Many factors including germination rate, biomass changes, biochemical changes, and nutrient changes must be determined in order to utilize a plant for phytoremediation. Our results showed that Prosopis pubescens (Screw bean mesquite) is a hyperaccumulator of copper from copper sulfate and a feasible option to remediate fields with up to 200 ppm of copper sulfate.

Screw bean mesquite seeds are viable even after 30 years of storage. Both copper sulfate and copper nitrate decreased the germination rate of screw bean mesquite seeds. In soil grown …

Swimming Performance Of Epigeal And Hypogeal Species Of Characidae, With An Emphasis On The Troglobiotic Stygichthys Typhlops Brittan & Böhlke, 1965, Francisco Alexandre Costa Sampaio, Paolo Santos Pompeu, Hersília De Andrade E Santos, Rodrigo Lopes Ferreira

International Journal of Speleology

Swimming performance of fish constitutes a good ecophysiological tool to evaluate the ability of species to use different types of habitats. In order to understand how the swimming performance is related to the hydraulic environment, we compared the critical velocity of five fish (Characidae): Stygichthys typhlops (groundwater troglobiotic); Piabina argentea and Bryconamericus stramineus (riverine); Hemigrammus marginatus (generalist, found in rivers and floodplains) and Psellogrammus kennedyi (lacustrine). Swimming speed tests were performed in a respirometer-type apparatus. Total body length was the variable that best explained the maximum speed attained by all species under study. The critical swimming speed values (in body …

Relationship Between Carbon Dioxide In Balcarka Cave And Adjacent Soils In The Moravian Karst Region Of The Czech Republic, Jiří Faimon, Monika Ličbinská, Petr Zajíček

International Journal of Speleology

Carbon dioxide concentration, air temperature, and humidity were monitored at (1) two cave sites and (2) three adjacent karst soils. The data over a one-year period are supported by dripwater chemistry and cave visiting frequency. The results indicate that the sources of cave CO2 are anthropogenic and epikarstic ones in addition to ordinary soils. Epikarstic CO2 produced under almost stationary conditions probably control dripwater chemistry and cave’s CO2 maxima. Based on breathing and door opening, anthropogenic activity affects instantaneous cave CO2 levels, depending on site volume/position and visitor number. A conceptual model of the CO2 dynamics of the soil-cave system …

Scientific Drilling Of Speleothems – A Technical Note, Christoph Spötl, David Mattey

International Journal of Speleology

This short article provides detailed descriptions of custom-made and commercially available hand-held drilling gear and options for water-flushing units specifically designed to obtained good-quality core material from speleothems even in remote cave regions. We use small-diameter (6-7 mm) diamond drill bits to obtain aliquots of calcite (as little as a few hundreds of milligram) from the interior of the basal part of in-situ stalagmites. These small cores are used to date the onset of stalagmite growth and occasionally to obtain other compositional information. Larger diameter drill bits produce cores 25-32 mm in diameter and up to 1.3 m in length …