Physical Sciences and Mathematics Commons^™

Modeling Visibility In The El Paso Del Norte (Pdn) Region, Richard Medina Calderon

Open Access Theses & Dissertations

Poor visibility is a subject of growing public concern throughout the U.S, and an active area of research. Its societal impacts on air quality, aviation transport and traffic are significant. Aerosols play a fundamental role in the attenuation of solar radiation, and also affect visibility. The scattering and extinction coefficients of aerosol particles in the Paso del Norte Region have been calculated using the T- matrix model in conjunction with a laser particle counter. Inter-comparison of the model's results of the scattering and absorption coefficients against the corresponding data from a Photoacustic extinctiometer instrument (which measures in-situ absorption and scattering …

Carbon Emissions From Soil Respiration In The Northern Chihuahuan Desert Shrubland, Anna Cristina Ortiz

Open Access Theses & Dissertations

The United States Department of Agriculture's Jornada Experimental Range (JER), is located in the northern Chihuahuan Desert in southern New Mexico and historically functioned as an experimental rangeland for cattle grazing. Historical grazing in the US Southwest has been identified as a leading, but not the sole, factor that has led to the conversion of pristine grasslands to shrublands, such has been the case on the JER. The estimated increased variability in precipitation intensity and frequency that is predicted to occur with climate warming will likely affect ecosystem responses from ecological processes including primary productivity, microbial decomposition, and thus respiration. …

Environmental Education Through The Lens Of Diverse Elementary School Students In The United States: A Phenomenographic Study, Brissa Yazmin Quiroz

Open Access Theses & Dissertations

Global environmental change is occurring, putting our planet under pressure. Children need to understand not only why the environment is important, but also their role as citizens of a globalized society and their necessary contribution to solving global problems. Students carry their own perspectives about the environment and education, and these differing perspectives should be a significant topic for environmental education research. Recent research studies have included the conceptualization of nature and the environment through children's eyes; yet, no studies have examined the concept of environmental education through the eyes of diverse children. Minority voices and experiences are not frequently …

Heavy Metal Pollution In The Paso Del Norte Region:Historical Reconstruction And Source Interpretation, Eugenia G. Shekhter

Open Access Theses & Dissertations

A unique and complex situation of heavy metal pollution arose in the El Paso del Norte region, one of the largest and oldest metropolitan areas on the US-Mexican border. This region with its complex topography is home to more than 2.2 million people sharing the same environment. Although many studies have been conducted in the region to identify the sources of environmental contamination, the cumulative history of heavy metal pollution is still incomplete. In order to identify the patterns of heavy metal dispersion and to test the hypothesis that the American Smelting and Refining Company (ASARCO) was a considerable contributor …

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

Open Access Theses & Dissertations

No abstract provided.

A Systematic Approach To Manage Missing Data In Pavement Management Systems, Mazin M. Al-Zou'bi

Open Access Theses & Dissertations

Pavements are an important part of the highway transportation infrastructure, accounting for the largest share of the overall investment. A tremendous amount of time and money is spent each year on the construction of new pavements, as well as on the maintenance and rehabilitation of existing pavements.

Transportation agencies use pavement management systems (PMS) for their maintenance and rehabilitation planning, programming, and budgeting. PMS are used to make decisions regarding when maintenance and rehabilitation should be applied. The systems also select what type of treatment should be applied for each pavement section in the network with clear estimations of the …

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 …

Application Of Various Remote Sensing And Aerial Photography Data Sets To Resolve Surface Structure In Areas Of Poor Exposure: Examples From Kamchatka Peninsula, Russia And Katalla Area, Alaska Usa, Sarah Natalie Heinlein

Open Access Theses & Dissertations

For many years now remote sensing data sets and application techniques of these various data have been routinely used in geological studies. Some of these studies are as basic as using Google Earth applications for general reconnaissance to more sophisticated methods for energy exploration or development of active tectonic models for a region. This dissertation presents data from two study areas within the northern pacific region utilizing a number of remote sensing and aerial photography data: 1) Kamchatka Peninsula, Russia, and 2) Katalla area of southern Alaska, USA. The Kamchatka Peninsula, Russia study evaluates surface geomorphology which includes the morphology …

Analysis Of Vehicle Interactions On Interstate Highways: Discrete Choice And Linear System Approaches, Alicia Romo

Open Access Theses & Dissertations

The research in this dissertation developed statistical and linear system models to predict driving behavior according to driver attributes, vehicle characteristics, car-following dynamics and/or driving conditions. The scope of this research was limited to the interaction of two vehicles traveling in the same direction on interstate highways.

The statistical models proposed in this research investigated the contributions of the different vehicle types on the manner and likelihood of collision. Discrete choice models were used to estimate the probability of the types of collision (rear-end, angle and sideswipe) as functions of driver attributes, striking and struck vehicle types, pre-crash driving actions …

Purification Of Sodium Sulfate By Crystallization, Perla Teresita Torres

Open Access Theses & Dissertations

Sodium sulfate can be recovered from a dilute solution by concentrating it by conventional water treatment techniques like reverse osmosis and electrodialysis; however, those processes also concentrate impurities like arsenic. The sodium sulfate would have commercial use if it can be recovered in an arsenic-free form. This study demonstrated that sodium sulfate could be separated from impurities using slow cooling crystallization in a novel apparatus developed and designed during the experimentation. This device is called a heat exchanger crystallizer and allows slow cooling crystallization in order to grow pure crystals of sodium sulfate decahydrate. Crystals grown in the heat exchanger …

Recovering Magnesium Hydroxide And Sodium Chloride From Zero Discharge Desalination Concentrate Streams, Alemayehu Asfaw Yetayew

Open Access Theses & Dissertations

UTEP and Veolia Water Solutions & Technologies have been demonstrating and commercializing the Zero Discharge Desalination (ZDD) technology as part of a three year project sponsored by the U.S. Bureau of Reclamation. ZDD is able to achieve up to 98% recovery by desalinating brackish groundwater. ZDD is typically comprised of a reverse osmosis (RO) or nanofiltration (NF) system and a unique variation of electrodialysis called electrodialysis metathesis (EDM). The ZDD technology increases the yield of fresh water from water supplies that contain enough CaSO4 to cause precipitation problems when the water is treated with RO or NF alone. The EDM …

Using Emotion As Inferred From Prosody In Language Modeling, Shreyas Ashok Karkhedkar

Open Access Theses & Dissertations

Research has focused on using prosody as an alternative source of information for language modeling. However, prosody is a surface phenomenon and to develop deeper models of language production, the underlying mental processes need to be considered. There are several cognitive factors, such as dialog-states and formulation, that have been given attention. However, emotion { as a cognitive factor, has been neglected so far. Speakers' emotional state plays an important role in spoken dialog. Participants seem to infer each others emotional state from multiple cues and react accordingly. In particular, these states manifest themselves moment-by-moment in the speakers voice. This …

An Approach To Power Efficiency Determination In The Solar Energy Systems Using Central Composite Design And Box-Behnken Design, Juan Venegas Mendez

Open Access Theses & Dissertations

We are living in an industrialized world that relies on fossil fuels. The ways, in which these fossil fuels have damaged the earth, in special the environment is worth of special attention and corrective actions. In our days, the climate change (global warming) it is becoming the number one topic. These changes are affecting our health, comfort and our way of living. Solar systems have been working among us since several years, but the truth is that most of us really don't understand how they work and more important, how they work in time in different conditions. Solar panels are …

Post-Pareto Optimality Methods For The Analysis Of Large Pareto Sets In Multi-Objective Optimization, Victor Manuel Carrillo

Open Access Theses & Dissertations

Multiple objective optimization involves the simultaneous optimization of more than one, possibly conflicting, objectives. Multiple objective optimization problems arise in a variety of real-world applications. In general, the main difference between single and multi-objective optimization is that in multi-objective optimization there is usually no single optimal solution, but a set of equally good alternatives with different trade-offs, also known as Pareto-optimal solutions. There are two general approaches to solve multiple objective optimization problems: mathematical methods and meta-heuristic methods. The first approach involves the aggregation of the attributes into a linear combination of the objective functions, also known as scalarization. The …

Determination Of The Effects Of Zno And Ceo2 Nanoparticles In Mesquite (Prosopis Juliflora) And Soybean (Glycine Max): Synchrotron And Spectroscopic Approaches, Jose Angel Hernandez Viezcas

Open Access Theses & Dissertations

The rapid growth of nanotechnology is exposing the environment to abnormal concentrations of engineered nanoparticles (NPs). There is concern about the unknown consequences of NPs on the environment and human health. This Dissertation has relied significantly on Synchrotron and other spectroscopic techniques to give insights on the effects, speciation and distribution of two metal oxide nanoparticles (ZnO, CeO2) on two plant species (Mesquite and Soybean). We evaluated the effects of ZnO (10 nm) and CeO2 (8 nm) NPs on a plant species native to the semi-arid regions of North America, Mesquite (Prosopis juliflora velutina). Mesquite plants grown in hydroponic culture …

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 …

Investigating The Validity Of A Survey Intended To Gauge Mathematics Problem-Solving Disposition Along The Impulsive-Analytic Dimension, Miguel Mendoza

Open Access Theses & Dissertations

This study investigates the validity of the Likelihood-to-Act (LtA) survey developed to assess respondents' problem-solving disposition along the impulsive-analytic dimension. Sixteen pre-service teachers were strategically selected from a pool of 495 LtA survey respondents to participate in a semi-structured task-based interview approximately one hour in length. The interview consisted of three main parts: a problem solving section, a consistency section, and a classification section.

* Part 1 of the interview was developed to get interviewees to solve five open-response problems meant to elicit an impulsive response. Interviewees were also asked to verbalize their thought process in order for the researchers …

Data Anonymization That Leads To The Most Accurate Estimates Of Statistical Characteristics, Gang Xiang, Vladik Kreinovich

Departmental Technical Reports (CS)

To preserve privacy, we divide the data space into boxes, and instead of original data points, only store the corresponding boxes. In accordance with the current practice, the desired level of privacy is established by having at least k different records in each box, for a given value k (the larger the value k, the higher the privacy level).

When we process the data, then the use of boxes instead of the original exact values leads to uncertainty. In this paper, we find the (asymptotically) optimal subdivision of data into boxes, a subdivision that provides, for a given statistical characteristic …

Physical And Sequence Stratigraphy Of The Late Cretaceous Chispa Summit Formation, Jeff Davis County, Texas, Patrick Thomas Dietzel

Open Access Theses & Dissertations

The Late Cretaceous Chispa Summit Formation of west Texas has historically been of interest to the petroleum industry; with new technologies, this old, uneconomical play could prove significant, if not for energy resources, for educational purposes, but little work has been conducted on the formation. The Eagle Ford Formation of southern Texas is time equivalent to the Chispa Summit Formation and is a highly prolific hydrocarbon resource.

Located in western Jeff Davis County, Texas, the Chispa Summit Formation consists of marine shales interbedded with limestone beds and sporadically located siliciclastic beds, measuring a total of 610 m at the type …

Comparison Of Bayesian Nonparametric Density Estimation Methods, Adel Bedoui

Open Access Theses & Dissertations

Density estimation has a long history in statistics. There are two main approaches to density, estimation parametric and nonparametric. The first approach requires specification of a family of densities f and estimation of the unknown parameter $\theta$ using a suitable estimation method, for example, maximum likelihood estimation. This approach may be prone to bias that arises from either estimation of the parameter or from incorrect specification of the probability distribution. The second approach, does not assume a specific parametric family.

In this thesis, we implement three density estimation methods that use Bayesian nonparametric approaches utilizing Markov Chain Monte Carlo methods. …

Software Development For A 3d Gravity Inversion And Application To Study Of The Border Ranges Fault System, South-Central Alaska, Rolando Cardenas

Open Access Theses & Dissertations

The Border Ranges Fault System (BRFS) bounds the Cook Inlet and Susitna Basins, and is an important petroleum province within south-central Alaska. A primary goal of our research is to test several plausible models of structure along the BRFS using a novel three-dimensional inversion technique utilizing gravity data, constrained with other geophysical, borehole and surface geological information. This research involves the development of 3D inversion modeling software using C++ Builder from Embarcadero's XE2 Suite. The novel inversion approach directly models known geology with a priori uncertainties assigned to the geologic model to allow researchers to compare alternative interpretations. This technique …

Improved Efficiency Of Rna Secondary Structure Prediction Using Distributed Computing, Gerardo A. Cardenas

Open Access Theses & Dissertations

The rapidly growing amounts of available biomolecular sequence data, which may represent information from small gene fragments to large complete genomes, have led to the a great need for powerful computational resources for data analysis and storage. With the decoding of the human and other genomes, RNA secondary structure prediction has become an important area of interest in biology and medicine because they help in understanding the mechanisms of many biological processes such as gene regulation and viral replication, and in designing RNA-based therapies to treat various diseases. Due to the complexity of their algorithms, many existing and upcoming computational …

A Declarative Domain Independent Approach For Querying And Generating Visualizations, Nicholas Ricky Del Rio

Open Access Theses & Dissertations

Constructing visualizations using modular visualization environments (MVEs) requires knowledge about visualization transformation theory as well as implementation specific details about how to programmatically chain together relevant sets of modules into pipe and filter-like architectures known as pipelines. Constructing visualization pipelines introduces a number of challenges including: understanding how to transform raw data into forms that can be ingested by MVEs, identifying target modules that map data into graphical data, and understanding how to further transform resulting graphical data into forms that can be presented. Users typically must immerse themselves in a deluge of documentation and usage examples before becoming proficient …

Automatic Memory Management Policies For Low Power, Memory Limited, And Delay Intolerant Devices, Md Abu Jahid

Open Access Theses & Dissertations

Mobile devices such as smartphones and tablets are energy and memory limited, and implement graphical user interfaces that are intolerant of computational delays. Mobile device platforms supporting apps implemented in languages that require automatic memory man- agement, such as the Dalvik (Java) virtual machine within Google's Android, have become dominant. It is essential that automatic memory management avoid causing unacceptable interface delays while responsibly managing energy and memory resource usage. Dalvik's automatic memory management policies for heap growth and garbage collection scheduling utilize heuristics tuned to minimize memory footprint. These policies result in only marginally acceptable response times and garbage …

Model Fusion: A New Approach To Processing Heterogeneous Data, Omar Ochoa

Open Access Theses & Dissertations

In many practical situations, it is necessary to extract

information from data of different types. For example, in geosciences, several sources of data can be used to determine the interior structure of the earth: the first arriving waves from earthquakes and from man-made sources, measurements of the earth's gravity field, measurements of the dispersion of surface waves generated by earthquakes, etc. At present, most existing data processing techniques deal only with data of one type.

A joint use of all the information derived from multiple types of data sources is an important theoretical and practical challenge. Such a joint use …

Geochemical Characterization Of Mineral Dust Sources In The Chihuahuan Desert And Southern High Plains Regions, Porfirio Peinado

Open Access Theses & Dissertations

The Chihuahuan Desert (northern Chihuahua, southern New Mexico, and far west Texas) and the southern High Plains (west Texas and eastern New Mexico) regions have been identified as one of the most persistent dust producing regions of North America. Regional-scale dust storms have been observed by satellite imagery to identify sources of dust, resulting in collection and examination of physical soil samples to better understand the source signatures (geochemical characteristics) of dust origins in these two regions.

The soil characteristics were examined through several techniques: Particle Size Distribution, X-Ray Diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), and Total …

Unconstrained L1 Optimization With Applications To Signal And Image Processing, Carlos Andres Ramirez

Open Access Theses & Dissertations

In recent years, the applied mathematical community has witnessed a revolution that is changing the paradigm of classical signal and image processing. Novel and e efficient numerical algorithms have emerged for solving new challenges in large scale signal retrieval, where both constrained and unconstrained L1 minimization methods play a fundamental role.

In this work, we present a new methodology for solving unconstrained L1 minimization problems in the context of image and signal processing. Our approach consists in solving a sequence of relaxed unconstrained minimization problems depending on a positive regularization parameter that converges to zero. The optimality conditions of each …

Developing A Sustainable Ecotourism Foundation In Indonesian National Parks Using Cross-Cultural Adaptation And Communication Framing, Adriana Salas

Open Access Theses & Dissertations

Previous research on ecotourism in Southeast Asia has focused on its positive and negative effects for conservation. However, the focus in this particular study is to look at what it takes to run a successful ecotourism site in four diverse areas in Indonesia using communication elements like cross-cultural adaptation and communication framing. Communication should be used as a baseline for a successful site and should be used as the most useful tool to address issues and challenges in ecotourism project development.

A successful ecotourism site must carefully look at how their ideas and programs are framed. Ecotourism must also create …

Evaluation Of Emission Control Strategies To Reduce Ozone Pollution In The Paso Del Norte Region Using A Photochemical Air Quality Modeling System, Victor Hugo Valenzuela

Open Access Theses & Dissertations

Air pollution emissions control strategies to reduce ozone precursor pollutants are analyzed by applying a photochemical modeling system. Simulations of air quality conditions during an ozone episode which occurred in June, 2006 are undertaken by increasing or reducing area source emissions in Ciudad Juárez, Chihuahua, Mexico.

Two air pollutants are primary drivers in the formation of tropospheric ozone. Oxides of nitrogen (NOx) and volatile organic compounds (VOC) undergo multiple chemical reactions under favorable meteorological conditions to form ozone, which is a secondary pollutant that irritates respiratory systems in sensitive individuals especially the elderly and young children.

The U.S. Environmental Protection …

Interaction Of Ceo2 And Zno Nanoparticles Towards The Symbiotic Association Of Alfalfa (Medicago Sativa) And Sinorhizobium Meliloti In Soil, Susmita Bandyopadhyay

Open Access Theses & Dissertations

The production of engineered nanoparticles (ENPs) has rapidly increased due to their wide range of applications in the field of electronics, medicine, chemistry and biology. Consequently, concerns have risen about the environmental release and potential negative impact of NPs. A few reports have described the effects of TiO2 NPs and quantum dots upon nitrogen fixing bacteria. However, the understanding of the interaction of NPs in plant-microbe interface (symbiotic association), like alfalfa (Medicago sativa L.)-Sinorhizobium meliloti, is still in its infancy. Alfalfa is the world's most important forage crop. It grows in association with S. meliloti, which is very important in …