Engineering Commons^™

Impulse Oscillometric Features And Parsimonious Respiratory Models Track Small Airway Function In Hispanic And Anglo Children, Erika Guadalupe Meraz Tena

Open Access Theses & Dissertations

Asthma is an inflammatory condition of the peripheral (small) airways resulting in airway hyper-reactivity and, among other symptoms, airflow obstruction. It is the most prevalent chronic respiratory disease in children. Reliable and patient-friendly instruments and methods are required to help pulmonologists accurately detect asthma and Small Airway Impairment (SAI) with acceptable clinical accuracy, specificity and sensitivity. Impulse Oscillometry System (IOS) based on the Forced Oscillation Technique (FOT) has been successfully used to measure lung function in children with a high degree of sensitivity and specificity to SAI and Asthma. IOS is a patient-friendly lung function to measure the mechanical impedance …

Oxidation Of Zrb2-Tic-Y2o3 At 1700c, Brenda Mota

Open Access Theses & Dissertations

The oxidation of plasma-sintered ZrB2-TiC-Y2O3 samples in air and a CO/N2 atmosphere has been investigated at 1973 K. The TiC was added to develop a TiO2 similar to a SiO2 layer, which has been an effective diffusional layer for the ZrB2-SiO2 system. Yttria was added to determine whether sufficient stabilization of the tetragonal-ZrO2 (t-ZrO2) could occur to minimize the monoclinic-ZrO2 transformation, which causes susceptibility to thermal shock of any ZrO2 containing composite.

The oxidized samples developed an outer layer of TiO2-B2O3 liquid acting as a sealant but with significant voidage as a result of B2O3 vaporization. Cracking initiated on the …

Tin Dioxide Memristors On Glass And Plastic Substrates, Oscar Del Real

Open Access Theses & Dissertations

NanoMIL has studied and developed SnO2-based memristors, while the W.M Keck Center has been a research leader in printed silver inks. The focus of this thesis is to take the previous generation of memristors on glass and develop a process for creating memristors on flexible Kapton film for the first time. Moreover, collaborative work between the two UTEP laboratories produced memristors with printed silver top electrode contacts, also for the first time. These approaches may enable inexpensive flexible memory.

Maturation of the process was achieved by understanding important process parameters and subtle differences between glass and Kapton substrates. Moreover, electrical …

Size Dependent Melting And Diffusion Of Silicon For Microsystem Applications, Noel Felipe Marquez

Open Access Theses & Dissertations

The size dependent reduced melting point and hydrogen enhanced surface diffusion effect on silicon nanostructures was explored experimentally. SOI and silicon wafers were patterned using nanimprint lithography and dry etching to explore the reduced melting point effect; and patterned with photolithography and dry etching to explore the hydrogen enhanced surface diffusion. The nanotextured samples were annealed in a wide variety of furnaces with nitrogen, forming gas, and argon atmospheres. Nitrogen was found to block the reshaping effect while argon was found to cause extensive pitting damage in the setup used. Micropatterned samples were annealed in a low pressure hydrogen enabled …

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

Open Access Theses & Dissertations

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

Development Of A Gis Fiber Optics Assetmanagement System For The City Of El Paso, Luis Fernando Quintana

Open Access Theses & Dissertations

The GIS Fiber Optics Asset Management System (GFOAMS) was developed for the City of El Paso, to manage the public fiber optics infrastructure. Using a map-driven interface, the GFOAMS is composed of three modules: inventory, documents, and images. Its interactive multilayer data structure contains information for Junction Boxes, Conduit Runs, and Cables for twelve fiber optic systems across the city. The fiber optics network stored in the GFOAMS connects city buildings and facilities such as police departments, fire departments, municipal courts, health administration building, public transportation facilities/Sun Metro, libraries and others. Applications of the GFOAMS include tools to easy access …

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

Open Access Theses & Dissertations

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

Experimental Study Of Thermoelectric Properties For Randomly Distributed Carbon Nanotubes And Silicon Carbide Nanoparticles, Onasis Garcia

Open Access Theses & Dissertations

In this experimental study, the thermoelectric (TE) properties of carbon nanotubes (CNTs) and Silicon carbide (SiC) nanoparticles have been investigated. Nanoparticles were randomly disrtibuted on a non-conductive glass or quartz substrate. The carbon nanotubes used were single-walled and multi-walled type, consisting of approximately 60% semiconducting 40% metallic tubes. The experimental design is analogous to that of a thermocouple measurement, with the nanoparticle layers creating hot and cold joints with a dissimilar metal Alumel (Ni-Al). Voltage (mV), current (μA) and resistance (Ω) values were measured with respect to temperature (°C), and Seeback coefficient values were also calculated in parallel. Summarized results …

A Combined X-Fem And Level Set Approach For Modeling Composite Material's Micro Structure, Himanshu Kumar

Open Access Theses & Dissertations

Composite materials are usually made of fibers and binding matrix. It's always a challenge to model composite materials' microstructure through the traditional finite element method because construction of an approximation space which is discontinuous across a given line or surface will place strict restrictions on the FE mesh. The interfacing of fibers in composites' microstructure through the standard finite element method is irksome and tedious because the presence of fiber presents a discontinuity in the binding material. In this present work, the composite's microstructure is modeled through the combined approach of Level Set and Extended Finite Element Method. The fiber …

Psychophysical Similarity Based Feature Selection For Nodule Retrieval In Ct, Ravi K. Samala

Open Access Theses & Dissertations

The emerging paradigms in cancer research indicate the need for a multi-perspective and multi-modal screening approach for early lung cancer diagnosis to increase the probability of clinical resection. Currently no standalone screening methodology is proved to suffice for a clinical diagnosis. Computed tomography has been proved to present abnormality at an early stage with less impact on survival rate in population studies. Nevertheless, because of its non-invasive characteristic, it can be used for diagnosis, prognosis and visualization of tumor. Studies have shown that Computer aided diagnosis (CAD) as a second reader can perform in a similar capacity as a radiologist. …

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

Open Access Theses & Dissertations

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

To answer this question, this research …

Development Of A New Mix Design Method And Specification Requirements For Asphalt Treated Bases, Hector Antonio Hernandez

Open Access Theses & Dissertations

Asphalt stabilized bases in Texas are usually designed and constructed as per Item 292, "Asphalt Treatment (Plant Mixed)," of the 2004 Standard Specification book. This specification is a hybrid of base and hot mix asphalt concrete procedures and requirements, which are sometimes incompatible. In addition, this Item uses a specific Texas Gyratory compactor that is not readily available to all districts. Some districts have started using test method Tex-204-F, Part III, `Mix Design for Large Stone Mixtures Using the Superpave Gyratory Compactor." However, this procedure was originally developed to design Type A and Type B hot mix at 96% density …

Impact Of Truck Suspension And Road Roughness On Loads Exerted To Pavements, Shahram Misaghi Bonabi

Open Access Theses & Dissertations

A software package, called IntPave, an Integrated Pavement Damage Analyzer, was developed at the Center of Transportation Infrastructure Systems at The University of Texas at El Paso with the capacity to calculate the pavement distress for flexible pavements under any type of traffic load, and to make a comparison of the level of distress caused by a standard and a non-standard, assuming statically exerted loading. However, what has been lacking is a tool to measure the dynamic impact on the pavement due to vehicle-road interaction. In this report, the interaction of truck suspension systems with the roughness of the road …

Fractal-Cosysmo Systems Engineering Cost Estimation For Complex Projects, Manish Shivram Khadtare

Open Access Theses & Dissertations

Cost estimation for engineering projects has advanced beyond the bottom-up counting of costs and the top-down use of analogies. Parametric cost estimation is now employed to estimate volatile software costs, as well as the cost of Systems Engineering (SE) effort in engineering projects. The Constructive Systems Engineering Cost Model (COSYSMO) estimates the number of Person-Months (PM) necessary to complete systems engineering projects by using project size and cost parameters. On re-examining the nature of systems engineering and the structures of complex projects that must be built in an orderly fashion on a variety of scales, it is apparent that a …