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Articles 1261 - 1290 of 2316

Full-Text Articles in Physical Sciences and Mathematics

Genesis Of Unique Carbonate Fans In A Pre-Salt Reservoir Analogue, Indio Mountains, West Texas, Andre Llanos Jan 2017

Genesis Of Unique Carbonate Fans In A Pre-Salt Reservoir Analogue, Indio Mountains, West Texas, Andre Llanos

Open Access Theses & Dissertations

Hydrocarbon exploration in pre-salt sediments of rift basins on the South Atlantic Margin have proven to be successful major oil plays. Located on the western margin of the rift, the Brazilian pre-salt reservoirs of the Santos, Campos, and Espirito Santo Basins are hosted by lacustrine/marine-influenced carbonates that comprise laterally extensive, laminated microbialite facies. The Indio Mountains, located in West Texas, provide well-exposed outcrops of Lower Cretaceous marine and non-marine rift basin strata that can be considered a reservoir-analog to the South Atlantic Margin pre-salt facies. Of particular interest for hydrocarbon exploration are unique carbonate features that have been discovered in …


Integration Of Heterogeneous Traffic Data To Address Mobility Challenges In The City Of El Paso, Daniel Michael Mejia Jan 2017

Integration Of Heterogeneous Traffic Data To Address Mobility Challenges In The City Of El Paso, Daniel Michael Mejia

Open Access Theses & Dissertations

Transportation performance measures are defined as quantitative and qualitative indicators that rely on data or information to explain mobility, traffic congestion, safety, environmental sustainability and other factors. Although performance measures have been used for freeways and other highways, not many have been specified and applied to the freight transportation system. Under the Fixing America's Surface Transportation Act (FAST Act), state transportation agencies and metropolitan planning organizations in the United States are implementing freight performance measurement systems for performance assessment. This research aims to expand the existing limited freight performance measures and organize them into a comprehensive framework that can be …


Pyroelectric Ceramics As Temperature Sensors For Energy System Applications, Jorge Luis Silva Jan 2017

Pyroelectric Ceramics As Temperature Sensors For Energy System Applications, Jorge Luis Silva

Open Access Theses & Dissertations

Temperature is continuously monitored in energy systems to ensure safe operation temperatures, increase efficiency and avoid high emissions. Most of energy systems operate at high temperature and harsh environments to achieve higher efficiencies, therefore temperature sensing devices that can operate under these conditions are highly desired. The interest has increased in temperature sensors capable to operate and in harsh environments and temperature sensors capable to transmit thermal information wirelessly. One of the solutions for developing harsh environment sensors is to use ceramic materials, especially functional ceramics such as pyroelectrics. Pyroelectric ceramics could be used to develop active sensors for both …


Synthesis And Post-Synthetic Transmetalations Of Metal-Organic Frameworks Containing Bimetallic Centers, Jose Miguel Veleta Jan 2017

Synthesis And Post-Synthetic Transmetalations Of Metal-Organic Frameworks Containing Bimetallic Centers, Jose Miguel Veleta

Open Access Theses & Dissertations

The heterobimetallic metal-organic frameworks (MOFs) of the type HKUST-1 were obtained through post synthetic cation exchange processes, where Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylate) was exposed to solutions of Mn2+, Fe2+, Co2+, or Ni2+ at time intervals of 6, 12, 24, 36, 48, and 72 hours. The elemental composition of the products was analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES), showing partial substitution of copper ions in the frameworks. Transmetalations done with Mn2+ and Ni2+ show a relatively low cation exchanged through the different time intervals, with maximum transmetalation percentages of 2.4 % for Mn2+ and 2 % for Ni2+ …


Near-Surface And High Resolution Seismic Imaging Of The Bennett Thrust Fault In The Indio Mountains Of West Texas, Alan Thomas Vennemann Jan 2017

Near-Surface And High Resolution Seismic Imaging Of The Bennett Thrust Fault In The Indio Mountains Of West Texas, Alan Thomas Vennemann

Open Access Theses & Dissertations

My research investigates the structure of the Indio Mountains in southwest Texas, 34 kilometers southwest of Van Horn, at the UTEP (University of Texas at El Paso) Field Station using newly acquired active-source seismic data. The area is underlain by deformed Cretaceous sedimentary rocks that represent a transgressive sequence nearly 2 km in total stratigraphic thickness. The rocks were deposited in mid Cretaceous extensional basins and later contracted into fold-thrust structures during Laramide orogenesis. The stratigraphic sequence is an analog for similar areas that are ideal for pre-salt petroleum reservoirs, such as reservoirs off the coasts of Brazil and Angola …


Tracing Anthropogenic Salinity Inputs To The Semi-Arid Rio Grande River: A Multi-Isotope Tracer Approach, Sandra Garcia Jan 2017

Tracing Anthropogenic Salinity Inputs To The Semi-Arid Rio Grande River: A Multi-Isotope Tracer Approach, Sandra Garcia

Open Access Theses & Dissertations

Water is an important component for life and as such water quality and availability are major concerns in the world today. In arid to semi-arid regions, freshwater quality is especially important due to its scarcity. Elevated salinity of rivers in arid regions poses potentially devastating consequences for the communities that depend on these rivers as a source of freshwater. In the Rio Grande region, high salinity has led to severe reductions in crop productivity and accumulation of salts in soils. Salinity inputs into the river may come from both anthropogenic and natural sources. Thus, identifying and quantifying salinity inputs to …


Developing A System Dynamics Model Of The El Paso Water Resources System, Majid Alahmoradi Jan 2017

Developing A System Dynamics Model Of The El Paso Water Resources System, Majid Alahmoradi

Open Access Theses & Dissertations

The city of El Paso is growing rapidly, increasing water demand in a water-scarce region. In this research system dynamics modeling is applied to simulate dynamic behavior of the El Paso water resources system in order to investigate the city's portfolio based upon a supply-demand side and demand side management approach. System Dynamic simulation involves several steps, including system conceptualization, data collection, simulation model development, and model verification and sensitivity analysis. A high-level conceptualization of the El Paso water resources system is presented, including withdrawal sources, water and wastewater treatment facilities, water demands, and flow linkages are will be presented. …


Time Degradation Of Perovskites, Nazia Sharmin Jan 2017

Time Degradation Of Perovskites, Nazia Sharmin

Open Access Theses & Dissertations

Perovskite organic-inorganic compounds are of interest for photovoltaic purposes, unfortunately, some of the organic-inorganic elements tend to evaporate rather rapidly rendering the films less effective for photoelectric use. In this study, we examine the evaporation of Perovskite organic-inorganic compounds produced by several manufacturing techniques. In particular we perform XRF and XPS inspections as a function of time and determine the fabrication method that best conserves iodine and lead.


Spectroscopic And Microscopic Analysis Of Graphene For Sensor Applications, Tamanna Tasneem Khan Jan 2017

Spectroscopic And Microscopic Analysis Of Graphene For Sensor Applications, Tamanna Tasneem Khan

Open Access Theses & Dissertations

As a two-dimensional material, graphene shows very good thermal and electrical conductivities, which, with its unique optical properties, makes it suitable for a variety of applications. In this study, we present detailed investigations by confocal Raman and Drude model analysis of the material's changes and improvements, as it transitioned from 3D graphite to 2D graphene. Besides Raman spectral recording, which can detect single, a few, and multi-layers of graphene, confocal Raman mapping allows distinction of such domains and direct visualization of material inhomogeneity. Moreover, far-infrared transmittance measurements, which are related to electrical conductivity, demonstrate a distinct increase of conductivity with …


Bragg Gratings In Polarization Maintaining Optical Fiber As Three Dimensional Strain Sensor, Joel Quintana Jan 2017

Bragg Gratings In Polarization Maintaining Optical Fiber As Three Dimensional Strain Sensor, Joel Quintana

Open Access Theses & Dissertations

Fiber-Bragg Gratings (FBG) for Structural Health Monitoring (SHM) have been studied extensively as they offer electrically passive operation, electromagnetic interference (EMI) immunity, high sensitivity and multiplexing as compared to conventional electric strain sensors. FBG sensors written within polarization maintaining (PM) optical fiber offer ad- ditional dimensions of strain measurement, greatly reducing the number of sensors needed to properly monitor a structure. This reduction however, adds complexity to the dis- crimination of the sensorâ??s optical response to its corresponding applied strains. This Dissertation defines the set of algorithms needed to measure planar strain using PM-FBGs exclusively. It defines the minimum number …


Studies Of Direct Solar Irradiance And Aerosol Optical Depth Using An Mfrsr And A Microtop Sunphotometer In The El Paso-Juarez Airshed, Arjun Aryal Jan 2017

Studies Of Direct Solar Irradiance And Aerosol Optical Depth Using An Mfrsr And A Microtop Sunphotometer In The El Paso-Juarez Airshed, Arjun Aryal

Open Access Theses & Dissertations

The study of Solar Irradiance and Aerosol Optical Depth (AOD) plays an important role in understanding the regional and global climate distribution, and is also important in air pollution studies. In this work an MFRSR (Multi-Filter Rotating Shadowband Radiometer) and a Portable Microtop Sunphotometer were used to measure irradiances and to obtain optical depth values for the El Paso-Juarez Airshed. The Langley method applied on the MFRSR irradiance data was used to calculate the AOD values. The spatial distribution of AOD for this region was obtained using a Microtop Sunphotometer. The graphs were generated using GIS Shapefiles. In addition, the …


Constraining Times Of Extension In The Southern Rio Grande Rift And Basin And Range Using Apatite And Zircon (U-Th)/He Thermochronology, Julian Biddle Jan 2017

Constraining Times Of Extension In The Southern Rio Grande Rift And Basin And Range Using Apatite And Zircon (U-Th)/He Thermochronology, Julian Biddle

Open Access Theses & Dissertations

The Rio Grande rift and the Basin and Range are adjacent extensional domains that have evolved contemporaneously in western North America. Although the rift is often considered to be the easternmost boundary of Basin and Range extension, there is geologic and geophysical evidence that suggests the two are discrete provinces. Existing low-temperature thermochronologic data indicate that a period of synchronous extension occurred across the entire length of the rift from ~25-10 Ma. However, these studies were more focused on the northern and central sections of the rift, and thermochronologic data remains sparse in southern New Mexico. We collected rock samples …


Utilizing Historical Mosquito Surveillance Data To Investigate The Efficacy Of Municipal Fogging In Controlling Mosquito Population Density, Andrea Betina Carzoli Jan 2017

Utilizing Historical Mosquito Surveillance Data To Investigate The Efficacy Of Municipal Fogging In Controlling Mosquito Population Density, Andrea Betina Carzoli

Open Access Theses & Dissertations

Background: Mosquito borne diseases are the cause of many different disease syndromes and deaths in animals, both wild and domesticated, and humans of all ages and ethnicities. Though El Paso, TX is located in an arid region, mosquito populations are still rapidly growing in urban and agricultural communities and so are the mosquito borne illnesses. The most common vectors associated with mosquito borne illnesses in El Paso County are Culex quinquefasciatus, Culex tarsalis, and Aedes aegypti. Vector management is often the primary option to prevent and control outbreaks of mosquito borne illnesses and very often utilize fogging as the primary …


Predicting Individualized Treatment Effects Via Random Forests Of Interaction Trees, Annette Pena Franco Jan 2017

Predicting Individualized Treatment Effects Via Random Forests Of Interaction Trees, Annette Pena Franco

Open Access Theses & Dissertations

Abstract Not Available


Investigation Of Earthquake And Geyser Activity From Short-Term Nodal Array Deployment Centered At Old Faithful Geyser, Susana I. Garcia Jan 2017

Investigation Of Earthquake And Geyser Activity From Short-Term Nodal Array Deployment Centered At Old Faithful Geyser, Susana I. Garcia

Open Access Theses & Dissertations

Yellowstone National Park is home to an active caldera, centrally located on the North American continent. Several studies have concluded the existence of a hotspot that fuels the hydrothermal, geothermal and earthquake activity in the Yellowstone region. The geologic record of Yellowstone contains multiple layers of volcanic deposits that indicate the region experienced three previous massive volcanic eruptions dating back 2.05Mya, 1.2Mya and the most recent 640,000 years ago. Yellowstone is also home to one of the largest geothermal areas in the world. With this study, an in-depth look at seismicity and geyser events recorded within an active geothermal region, …


Analysis Of Bias-Corrected And Exact Estimators For Binomial Generalized Linear Model Parameters, Hamna Hannan Jan 2017

Analysis Of Bias-Corrected And Exact Estimators For Binomial Generalized Linear Model Parameters, Hamna Hannan

Open Access Theses & Dissertations

Typically, small samples have always been a problem for binomial generalized linear models. Though generalized linear models are widely popular in public health, social sciences etc. In small sample scenarios the non-existence of the maximum likelihood (ML) estimators is very common as well as separation occurs in the data. In logistic regression the maximum likelihood estimates are found to have biased away from origin. My work examines the bias-reduced and exact estimators that have been used to estimate the slope parameters and standard errors of the estimated slope parameters as compared to the traditional ML method.

The present work is …


Contextual Representation Of Documents, Entities, And Faces Of People Using A News Corpus, Md Abdul Kader Jan 2017

Contextual Representation Of Documents, Entities, And Faces Of People Using A News Corpus, Md Abdul Kader

Open Access Theses & Dissertations

A massive amount of unstructured data, in this information age, is composed of document collections. Examples include news articles, blog posts, scholarly publications, and reports generated by organizations as well as people. Many data mining and machine learning algorithms have been developed in the past decade to support text mining in many applications. Text mining applications cover a wide range of tasks spanning from personal information management --- to organizational decision making, to disease control through epidemic prediction, and to intelligence analysis for national security. One bottleneck has been dominating data mining and machine learning theories for all these text …


Cost-Effective Recovery Of Concentrated Cooling Tower Blowdown Using The Cerro Process, Lindsey Nicole Larson Jan 2017

Cost-Effective Recovery Of Concentrated Cooling Tower Blowdown Using The Cerro Process, Lindsey Nicole Larson

Open Access Theses & Dissertations

The Concentrate Enhanced Recovery Reverse Osmosis (CERRO) process is a seawater-RO unit that can cost-effectively achieve extremely high recoveries from water high in silica, carbonate and sulfate concentrations. This relatively new technology takes advantage of the induction time of potential foulants to recover more water than what is normally achievable with a conventional desalination system. The scope of the project was to evaluate the efficiency of the CERRO process as a pilot study using cooling tower blowdown which varied in water quality parameters daily. It was found that the CERRO pilot could successfully achieve 85% recovery, and the main limitation …


The Nonparametric Estimation Of Elliptical Distributions, Panfeng Liang Jan 2017

The Nonparametric Estimation Of Elliptical Distributions, Panfeng Liang

Open Access Theses & Dissertations

In practice, many multivariate datasets have identical marginal distributions. Elliptical distributions can be used to model many of those datasets. In this Thesis, we will propose a Bayesian method using Markov chain Monte Carlo (MCMC) methods to estimate the density function underlying multivariate datasets assuming it is an elliptical distribution.


A Comparison Of Uvr-Induced Mortality In Bdelloid Rotifers, Maite Martin Jan 2017

A Comparison Of Uvr-Induced Mortality In Bdelloid Rotifers, Maite Martin

Open Access Theses & Dissertations

Increases in UV radiation (UVR) reaching Earth's surface as a result of anthropogenic activities and changing climate patterns are having a variety of effects on ecosystems. Such effects have been observed in aquatic environments, although certain parameters such as dissolved organic carbon (DOC) concentrations can modulate the level of exposure. Bdelloid rotifers are aquatic micro-invertebrates that pose a remarkable variety of special abilities to survive adverse conditions, including a resistance to UVR. Previous studies have suggested this resistance may have evolved in response to episodes of desiccation that they experience in their natural habitats. This characteristic may be especially important …


Sample Size Estimation For Linear Mixed Models With Dependent End Points, Michael Nsiah-Nimo Jan 2017

Sample Size Estimation For Linear Mixed Models With Dependent End Points, Michael Nsiah-Nimo

Open Access Theses & Dissertations

The primary objective is sample size estimation in linear mixed model settings. Sample size estimation is an important component of planning a well thought out scientific experiment. Whenever sample size estimation is performed, taking into account a priori model based inferences will provide a sample size estimate that will achieve the desired power without inflating the type I error rate of the study.

One common practice is a traditional approach cited in the literature that uses the largest sample size after you Bonferroni the type I error rate to estimate sample sizes as such. We are going to take into …


Evaluating Binary Splits On Nominal Inputs, Isaac Xoese Ocloo Jan 2017

Evaluating Binary Splits On Nominal Inputs, Isaac Xoese Ocloo

Open Access Theses & Dissertations

The maximally selected statistic approach in building tree models is shown to be a cause of variable selection bias. In this study we propose three methods to solve this problem in building regression trees with nominal predictor variables. Out of the three methods

proposed we explored only two in detail and defer one for further research. We developed an exact method to compute the p-value corresponding to the maximized splitting statistic in regression trees for nominal predictor variables with at most 10 distinct levels and a

method to estimate the best cutoff point as a parameter in a parametric nonlinear …


Compressive Vector Reconstruction: Hypothesis For Blind Image Deconvolution, Alonso Orea Amador Jan 2017

Compressive Vector Reconstruction: Hypothesis For Blind Image Deconvolution, Alonso Orea Amador

Open Access Theses & Dissertations

Alternative imaging devices propose to acquire and compress images simultaneously. These devices are based on the compressive sensing (CS) theory. A reduction in the measurement required for reconstruction without a post-compression sub-system allows imaging devices to become simpler, smaller, and cheaper. In this research, we propose a new algorithm to compress and reconstruct blurred images for CS imaging devices. Blur effect in images is common due to relative motion, lens, limited aperture dimensions, lack of focus, and/or atmospheric turbulence. Our intention is to compress a blurred image with CS techniques and then reconstruct a blur-free version using the proposed algorithm. …


Analysing The Effects Of Data Augmentation And Free Parameters For Text Classification With Recurrent Convolutional Neural Networks, Jonathan Quijas Jan 2017

Analysing The Effects Of Data Augmentation And Free Parameters For Text Classification With Recurrent Convolutional Neural Networks, Jonathan Quijas

Open Access Theses & Dissertations

Convolutional neural networks have seen much success in computer vision and natural language processing tasks. When training convolutional neural networks for text classification tasks, a common technique is to transform an input sequence of words into a dense matrix of word embeddings, or words represented as dense vectors, using table lookup operations. This enables the inputs to be represented in a way that the well-known convolution/pooling operations can be applied to them in a manner similar to images. These word embeddings may be further incorporated into the neural network itself as a trainable layer to allow fine-tuning, usually leading to …


Describing Data And Workflow Provenance Using Design Patterns And Controlled Vocabularies, Smriti Rajkarnikar Tamrakar Jan 2017

Describing Data And Workflow Provenance Using Design Patterns And Controlled Vocabularies, Smriti Rajkarnikar Tamrakar

Open Access Theses & Dissertations

In any scientific experiment, researchers are required to access, compute, and analyze data to produce useful information to the scientific community. In order to instill trust on such scientific research products, the product users need to understand the procedure applied and the assumptions incorporated. The reuse and replication of reliable scientific data need methods that help the users to understand data origin and the derivation process, i.e. provenance. Although several standards for representing provenance such as PROV model (a W3C recommendation) have been recommended, they have not been widely utilized by scientific communities due to difficulty in aligning such recommended …


Using Underground Radon To Detect Inactive Geological Faults, Germán Rodríguez Ortiz Jan 2017

Using Underground Radon To Detect Inactive Geological Faults, Germán Rodríguez Ortiz

Open Access Theses & Dissertations

This Thesis presents the results of an investigation of the concentration of radon in soil around a fault in the East Franklin Mountains in the El Paso area in West Texas. The connection between underground radon exhalations near active faults has been known for decades, but possible similar increases of underground radon levels around inactive faults have not been studied as thoroughly. Arguing that the dilatancy-diffusion model used to explain the phenomenon near active faults does not apply to the case of inactive faults, a hypoThesis is formulated under which increased levels of underground radon must be present near inactive …


Household Water Consumption In El Paso, Texas: Perceptions And Behaviors Towards Water In Urban Households, Diego Armando Sanchez Jan 2017

Household Water Consumption In El Paso, Texas: Perceptions And Behaviors Towards Water In Urban Households, Diego Armando Sanchez

Open Access Theses & Dissertations

The main objective of this research is to determine perceptions and behaviors of household water consumption and to examine how those may affect the patterns of water use and consumption levels in households of El Paso, Texas.

I conducted a qualitative exploratory research to collect important data that is often left unexplored in quantitative research. The collected data is a mixture of qualitative and quantitative. I do report the quantitative data using descriptive statistics, which help the reader see basic patterns in the study.

Qualitative data can help to understand the reasons that impact water consumption perceptions and behaviors in …


Electronic Structure Studies On Transition Metal Containing Endohedral Fullerenes, Carbon Onions And Zinc Sulfide Cages, Shusil Bhusal Jan 2017

Electronic Structure Studies On Transition Metal Containing Endohedral Fullerenes, Carbon Onions And Zinc Sulfide Cages, Shusil Bhusal

Open Access Theses & Dissertations

We present the most stable structures for VXSc3-XN@C2n (where X=1-3 and 2n=70, 76, 78 and 80) using a systematic procedure that involves all possible isomers of the host fullerene cages. Subsequently, a detailed investigation of structural and electronic properties of the lowest energy isomers is performed using density functional theory in combination with large polarized Gaussian basis sets. The search procedure developed involved structural optimizations of thousands of fullerenes and correctly identifies the experimentally observed VSc2N@C80 and V2ScN@C80 isomer as the most stable structures. The structural analysis shows that a few V-doped endohedral fullerenes do not follow the isolated pentagon …


Which Value X Best Represents A Sample X1, ..., Xn: Utility-Based Approach Under Interval Uncertainty, Andrzej Pownuk, Vladik Kreinovich Jan 2017

Which Value X Best Represents A Sample X1, ..., Xn: Utility-Based Approach Under Interval Uncertainty, Andrzej Pownuk, Vladik Kreinovich

Departmental Technical Reports (CS)

In many practical situations, we have several estimates x1, ..., xn of the same quantity x. In such situations, it is desirable to combine this information into a single estimate x. Often, the estimates come with interval uncertainty, i.e., instead of the exact values xi, we only know the intervals [xi] containing these values. In this paper, we formalize the problem of finding the combined estimate x as the problem of maximizing the corresponding utility, and we provide an efficient (quadratic-time) algorithm for computing the resulting estimate.


F-Transform As A First Step Towards A General Approach To Data Processing And Data Fusion, Olga Kosheleva, Vladik Kreinovich Jan 2017

F-Transform As A First Step Towards A General Approach To Data Processing And Data Fusion, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In data fusion, we have several approximations to the desired objects, and we need to fuse them into a single -- more accurate -- approximation. In the traditional approach to data fusion, we usually assume that all the given approximations were obtained by minimizing the same distance function -- most frequently, the Euclidean (L2) distance. In practice, however, we sometimes need to use approximations corresponding to different distance functions. To handle such situations, a new more general approach to data processing and data fusion is needed. In this paper, we show that the simplest cases of such new …