Engineering Commons^™

Water Mass Balances For The Rio Grande/Bravo From Fort Quitman, Texas To Foster Ranch Near Langtry, Texas: An Assessment Of Factors, Ramiro Lujan

Open Access Theses & Dissertations

ABSTRACT

Water availability is declining in many regions of the planet, particularly in arid and semi-arid regions. Water bodies located in these regions, like the Rio Grande/Bravo at the U.S. - Mexico border, are subjected to high water demands. This research project makes an assessment of the spatial and temporal variability of elements intervening in the water mass balance for the section of the Rio Grande/Bravo between Fort Quitman and Langtry, Texas during the time period extending from January 1990 through December 2005. This document mentions the main Rio Grande/Bravo stakeholders from the U.S. and Mexico, and describes issues related …

Multi-Objective System Design Optimization Considering Environmental Emissions, Olivia Carolina Moreno

Open Access Theses & Dissertations

The well-known reliability optimization problem, the redundancy allocation problem (RAP) involves the simultaneous selection of system components and a design level configuration that can meet several design constraints in order to optimize the predefined objective function(s). The RAP has been predominantly solved as a single objective optimization problem with the reliability of the system to be maximized or system design cost to be minimized. When considered as a multiple objective reliability optimization problem, the system reliability is maximized and the cost and weight of the system are minimized. In this work, the RAP was formulated as a multiple objective optimization …

Evaluation Of A Cash Award Program For Water Conservation, Robert Moss

Open Access Theses & Dissertations

This document is the final report of a water conservation study funded by the U.S. Bureau of Reclamation and The University of Texas at El Paso with cooperation from El Paso Water Utilities. The study period was from September, 1997 through January, 2000.

Development Of A High Pressure Optically Accessible Combustor And Shear Co Axial Injector, Christopher David Navarro

Open Access Theses & Dissertations

A trend in the last decade in the field of propulsion and rocketry is leaning toward the use of the combination of Liquid Methane and Liquid Oxygen as propellant fuels. This is in contrast with the earlier trend of using Hydrogen systems and toxic hypergolic systems. The Multi-Purpose Optically Accessible Combustor (MOAC) and Shear Coaxial injectors have been developed to investigate injector design and combustion research involving Oxygen and Methane propellants. The MOAC is intended for the experimentation and research of combustion of liquid and gaseous propellants. Development of the MOAC system and versatility to use a number of injector …

Use Of Environmental Isotope Tracer And Gis Techniques To Estimate Basin Recharge, Abdulganiu A.A. Odunmbaku

Open Access Theses & Dissertations

The extensive use of ground water only began with the advances in pumping technology at the early portion of 20th Century. Groundwater provides the majority of fresh water supply for municipal, agricultural and industrial uses, primarily because of little to no treatment it requires. Estimating the volume of groundwater available in a basin is a daunting task, and no accurate measurements can be made. Usually water budgets and simulation models are primarily used to estimate the volume of water in a basin.

Precipitation, land surface cover and subsurface geology are factors that affect recharge; these factors affect percolation which invariably …

The Influence Of Build Parameters On The Microstructure During Electron Beam Melting Of Ti6al4v, Karina Puebla

Open Access Theses & Dissertations

With the demand of devices to replace or improve areas, such as: electronic, biomedical and aerospace industries. Improvements in these areas of engineering have been in need due to the customer’s needs for product properties requirements. The design of components must exhibit better material properties (mechanical or biocompatible) close to those of any given product. Rapid prototyping (RP) technologies that were originally designed to build prototypes may now be required to build functional end-use products. To carry out the transition, from RP to rapid manufacturing (RM), the available materials utilized in RP must provide the performance required for RM. The …

A Novel Method For The Curing Of Metal Particle Loaded Conductive Inks And Pastes, David Adrian Roberson

Open Access Theses & Dissertations

The emerging technology of printed microelectronics involving the use of conductive inks in conjunction with standard printing techniques offers a fast and low waste method for creating microelectronics compared with standard manufacturing processes. A clear path to the creation of flexible electronics is present due to the ease of printing on flexible substrates. Moreover, creation of novel 3D structural electronics is possible via the integration of printing technologies and additive manufacturing (AM) techniques.

A key obstacle to the manufacturing of flexible and structural electronics comes from the temperature restrictions imposed by the substrates, which are typically polymeric. This hindrance has …

Position Sensitive Device With Gaussian Response, Sinohe Rodriguez

Open Access Theses & Dissertations

Much work has been done in improving the linearization of position sensitive devices, PSDs. However, a novel way of position detection using Gaussian filters has recently been developed. An obvious extension of this approach is possible via the electro-optical implementation of the Gaussian filters. This thesis proposes a PSD that has such a Gaussian output response to an incident light spot moving across its surface. The proposed device is based on a simple and inexpensive p-n junction. The device is simulated using finite-difference frequency-domain numerical analysis within Matlab.

Investigation Of Gas-Solid Fluidized Bed With Non-Spherical Particles, Mario Alberto Ruvalcaba

Open Access Theses & Dissertations

The number of experimental and numerical studies of multiphase flows has remarkably increased over the last several years. This research has abundant applications in energy, chemical, and conversion processes. Common use of these technologies includes catalytic cracking for petroleum refineries, fluidized bed reactors (type of chemical reactor), interface modification, and has been an important technology breakthrough in coal gasification. The present work will concentrate on the investigation and validation of gas-solid flows utilizing numerical methods. The gas-solid flows study on this research assumes the solid and gas phases as continua with averaged properties.

The fluid flow computation was achieved using …

Determination Of The Dynamic Behavior Of Subjects With Diabetic Neuropathy, Luis G. Sagarnaga Lopez

Open Access Theses & Dissertations

The diabetic foot is one of the most feared complications of diabetes [3]. Causes of a diabetic foot come from many disorders including diabetic neuropathy, peripheral vascular disease, charcot's neuropathy, foot ulceration, and limb amputation [4]. Statistics have revealed that 8.3 percent of population in the U.S. is affected by diabetes in 2010, i.e., 25.8 million people. About 60 percent to 70 percent of people with diabetes have mild to severe forms of nervous system damage [13]. There is an enormous impact on the physical and mental health of patients who suffer from diabetes.

This research was to determine the …

Investigation On A Gas-Solid Fluidized Bed Hydrodynamics Using A Non-Intrusive Technology To Visualize Flow Field, Md Rashedul Hasan Sarker

Open Access Theses & Dissertations

The biggest challenge for 21st century is to fulfill global energy demand and at the same time reduce detrimental impact on environment. Gasification technology can meet the requirement and also reduce emission without compromising its performance. In coal gasification, instead of burning coal completely a partial combustion takes place with presence of steam and limited amount of oxygen. In this controlled environment a chemical reaction takes place and produces a mixture of clean synthetic gas. Gas-solid fluidized bed is one type of gasification technology. During gasification mixing behavior of solid (coal) and gas and their flow pattern very complicated to …

Evaluation Of Ozone Trends And Distribution In The Paso Del Norte Region Using Tceq's Cams Data And Ozone Data Collected At Two Supplemental Sites, Adrian Michael Sandoval

Open Access Theses & Dissertations

The purpose of this research was to determine whether the city of El Paso will continue to be in attainment if the Environmental Protection Agency (EPA) revises the National Ambient Air Quality Standards (NAAQS) of 8-hour average ozone concentration from 0.075 parts per million (ppm) to 0.070 ppm. For the duration of El Paso's ozone season, June-September 2012, two 2B Technology Ozone 202 monitors were deployed at proposed locations, not previously monitored. This was done in order to quantify concentration of ozone. In addition, ozone and meteorological data was downloaded from several Continuous Ambient Monitoring Stations (CAMS) in the Paso …

The Application Of Fuzzy Granular Computing For The Analysis Of Human Dynamic Behavior In 3d Space, Murad Mohammad Alaqtash

Open Access Theses & Dissertations

Human dynamic behavior in space is very complex in that it involves many physical, perceptual and motor aspects. It is tied together at a sensory level by linkages between vestibular, visual and somatosensory information that develop through experience of inertial and gravitational reaction forces. Coordinated movement emerges from the interplay among descending output from the central nervous system, sensory input from the body and environment, muscle dynamics, and the emergent dynamics of the whole neuromusculoskeletal system.

There have been many attempts to directly capture the activities of the neuronal system in human locomotion without the ability to clarify how the …

Measurement And Analysis Of Turbulent Syngas/Air And Methane Oxy-Combustion, Vishwanath Reddy Ardha

Open Access Theses & Dissertations

Development of a next generation gas turbine combustors for power production by using fossil fuels is increasing substantially in order to maintain energy sustainability. National Energy Technology Laboratory has made efforts for developing hydrogen and oxy-fuel based gas turbine combustors which could enhance plant efficiency and ensure low or zero NOx production without sacrificing operational advantages. The current experimental work aims to characterize the turbulent flow-field of premixed syngas/air flames, methane/oxy flames and syngas/oxy flames in a laboratory scaled burner by varying the Reynolds numbers, blockage ratios, firing inputs and blockage ratios in the upstream of the burner. The effects …

Transparent And Amorphous W-Ti-O Nano-Coatings, Gaurav Baghmar

Open Access Theses & Dissertations

The present work was performed on the Ti-doping effects in a small and controlled amount into WO3 to produce W0.80Ti0.20O3. The aim of study is to explore the effect of Titanium (Ti) coupled with growth temperature on the growth of behavior, microstructure and optical properties. W0.80Ti0.20O3 coatings were fabricated using RF magnetron sputter-deposition onto Silicon (Si-100) wafers and optical quality Quartz substrates. The depositions were made in a wide temperature ranging from room temperature (25 ˚C) to 500 ˚C. X-ray diffraction (XRD), high-resolution scanning electron microscopy (SEM), Optical spectrophotometery and Spectroscopic Ellipsometry (SE) were performed to study the effect of …

Ozone Studies In The Paso Del Norte Region, Fernando Becerra-Davila

Open Access Theses & Dissertations

The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment.

The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are …

Comparison Study Between Fem And Sem For Wave Propagation Models Applied To Solids, Shaddy Roberto Castillo Ponton

Open Access Theses & Dissertations

Wave propagation is a field whose application has spread across many disciplines. In the field of structural engineering, wave propagation methods have focused their attention specifically in the area of structural health monitoring and active control of vibrations and noise. Likewise, the development of new methods and their application have been successful in the area of material science with a special emphasis on the field of structural integrity evaluation of anisotropic and inhomogeneous structures (laminated composite structures). The current available analysis tools are inadequate to handle the modeling of complex structures. One-dimensional wave propagation problems in solids are still a …

Bod5 And Cod Data Analysis From The Northwest And Robert R. Bustamante Wastewater Treatment, Juan Carlos Adame

Open Access Theses & Dissertations

The objectives of this thesis are to explore the use of basic Statistical Process Control in a Wastewater Treatment Plant with secondary treatment. Additionally, to describe statistical behavior and review normality of some reportable parameters, also to analyze mainly parameters like BOD5 (Biological Oxygen Demand), Electrical Conductivity, and COD (Chemical Oxygen Demand) with seasons of the year and days of the week, using data from the Northwest (NW) and Robert R. Bustamante (RRB) Wastewater Treatment Plants from El Paso Texas.

The scope of this analysis is to understand how Statistical Process Control can help to predict peak and valleys of …

Structure Morphology And Optical Properties Of Nanocrystalline Ga2o3 Thin Films, Sampath Kumar Samala

Open Access Theses & Dissertations

Gallium Oxide thin films were produced by sputter deposition by varying the substrate temperature (T_s) in a wide range (T_s=25-800 oC) and under variable deposition time. The structural characteristics and optical properties of Ga₂O₃ films were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Rutherford backscattering spectrometry (RBS) and spectrophotometric measurements. The effect of growth temperature is significant on the chemistry, crystal structure and morphology of Ga₂O₃ films. XRD and SEM analyses indicate that the Ga₂O₃ films grown at lower temperatures were …

Graphene Stuctures For Energy Storage Application, Mohammad Arif Ishtiaque Shuvo

Open Access Theses & Dissertations

Energy storage devices are receiving extensive attention in recent years due to the increasing demand of energy. Super-capacitor is one of the energy storage devices with high specific power density and wide applications in electronic vehicles, commercial mobile electronics, and military devices. Carbon based materials are widely used in making Electrochemical Double Layer Capacitor (EDLC) or super-capacitor for their excellent porous nature along with their electron transport capability. By increasing the specific surface area of the porous carbon materials, specific capacitance of the super-capacitor can be significantly improved. Graphene, a newly discovered material, has been incorporated in making super-capacitor electrodes …

Development Of An Electronic Vehicle Miles Travelled Toll Model, Marketa Vavrova

Open Access Theses & Dissertations

This thesis presents the reasons why the fuel tax is no longer a viable source of revenues and suggests new sources of funding. One possibility is to replace the fuel tax with a distance-based toll applied nationwide. Vehicle miles travelled (VMT) fee is compared to the fuel tax, and the relationship between road infrastructure spending and fuel taxation in the United States (U.S.) and the European Union (EU) is explored. Also the European approach to taxation and tolling is described and compared to the situation in Texas.

The development of a statewide distance-based toll model to estimate the feasibility of …

A Study Of International Wastewater Challenges And Policy In The Tijuana River Watershed, Gloria Ann Villaverde

Open Access Theses & Dissertations

Since the 1930s, untreated and undertreated sewage from Tijuana, Baja California, México has been released into the Tijuana River Watershed causing contamination of the water supply, crops, the Tijuana Estuary and California beaches. Passage of the North American Free Trade Agreement (NAFTA) has exacerbated the problem by causing population and industrial growth explosions for which there have been insufficient services to meet the needs of the people. The waters of the Tijuana River flow (from México) north over the International Border, into the Tijuana Estuary, discharge out to the Pacific Ocean and often flow north, up the California Coast; therefore, …

The Effects Of Uncommon Silicides On The Oxidation Of Alloys From The Nb-Cr-Si System, Daniel Brendan Voglewede

Open Access Theses & Dissertations

Niobium based alloys are being tapped as potential successors to current nickel base superalloys in high temperature applications. In the aerospace industry, high temperature materials are constantly being pushed to higher temperature regimes in order to improve engine efficiency however current superalloys cannot be pushed further due to melting temperature limitations. Niobium, being a refractory metal, can withstand much higher temperatures than nickel however its oxidation properties are woefully inadequate.

The purpose of this study is to ascertain whether increased silicon additions can improve niobium oxidation properties by: forming ternary silicides with better oxidation properties and by preventing the formation …

Designing Optimal Aviation Baggage Screening Strategies Using The Monkey Search Algorithm, Edgar Ivan Jimenez

Open Access Theses & Dissertations

This thesis addresses the aviation baggage screening design problem considering several baggage screening devices which may be used for system implementation, the devices have different false clear and false alarm rates, throughput and purchase costs. In the present research, a comprehensive cost function which not only includes the cost associated with purchase and operation of baggage security devices, but also includes the indirect costs associated with device errors is used. A new monkey search based evolutionary algorithm is presented to determine the best selection of baggage screening security devices in order to minimize the expected annual total cost. The final …

Investigation Of A Water Desalination Method Via A Humidification-Dehumidification Process Using Hvac Technology, Juan Antonio Cornejo

Open Access Theses & Dissertations

Potable water is becoming a scarce resource in many arid regions of the world. An experimental unit was designed and constructed to examine and characterize the production capabilities of a humidification-dehumidification (HDH) desalination process. An HDH cycle offers a viable, technologically light, alternative for producing fresh water from brackish water because the low relative humidity air is infused with water vapor through evaporation by means of conventional heating, ventilation and air conditioning (HVAC) components. The evaporation process effectively separates salts and suspended solids from the brackish feed-water. Desalinated water is subsequently recovered by extracting the water vapor from the moist …

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 …

Development Of A Multi-Material, Multi-Technology Fdm System For Process Improvement Experimentation, David Espalin

Open Access Theses & Dissertations

Over the last three decades, developments within the area of Additive Manufacturing (AM) have resulted in novel technologies capable of producing highly customized, complex part geometries in a fraction of the lead time required by traditional manufacturing methods (e.g., injection molding, metal casting). In particular, fused deposition modeling (FDM), a material extrusion AM process, can produce parts using production-grade thermoplastics like acrylonitrile butadiene styrene, polycarbonate, and polyetherimide. Additionally, non-commercial materials (e.g., polycaprolactone, ceramic loaded polymers, carbon nanotube loaded polymers) have been processed using FDM in part to demonstrate the potential diversity in material selection.

Recently, a myriad of personal 3D …

The Effect Of Al And B Additions On The Oxidation Behavior Of Alloys From The Nb-Cr-Si System, Nydia Judit Esparza

Open Access Theses & Dissertations

Nickel based superalloys have been developed to perform substantially in industry however as technology develops, the need and desire to increase service temperatures to improve efficiency and performance is pushing the capabilities of these alloys. These aspired requirements entail the research and development of new structural materials that surpass the abilities of nickel alloys. Research in Nb-based alloys is underway as Nb alloys have shown to be a promising alternative with similar density but higher melting temperatures than the Ni alloys. However, because Nb has poor oxidation properties extensive studies are necessary to develop an alloy that can perform as …

Optimal Placement Of Wind Turbines On Non-Flat Terrain Using Cluster Identification And Multi-Objective Genetic Algorithm, Carlos Alejandro Garcia Rosales

Open Access Theses & Dissertations

To date, wind power has become very popular to produce electricity due to climate change, greenhouse gases and the fossil fuels crisis. Although using wind turbine technology to produce electricity is very mature, industries are looking to achieve the best utilization of the wind energy in order to fulfill the electrical needs for cities at a very affordable cost. In this thesis, a method entitled Cluster Identification Algorithm (CIA) and an optimization approach called a Multi-Objective Genetic Algorithm (MOGA) are integrated and implemented to maximize wind power efficiency and wind power in wind farms and minimize cost caused by the …

Placement Of Multiple Base Stations For Energy Efficient Communication In Wireless Sensor Networks, Nagendra Kiran Kambhampati

Open Access Theses & Dissertations

In recent years, the importance of multiple base stations in Wireless Sensor Networks (WSNs) has increased in applications such as environmental, border zone control, etc. Due to the energy constraints in individual sensor nodes, extending lifetime is an essential objective in WSNs. The physical, medium access and network layers have been targeted by a number of researchers for designing energy efficient protocols. While the proposed protocols were successful in energy savings for individual sensor nodes, they fail to solve problems related to the topology of the network. An example of such problem is that sensors nodes around the base station …