Digital Commons Network^™

Low Power Design Techniques For Data Acquisition, Praveen Kumar Palakurthi

Open Access Theses & Dissertations

Semiconductor technology advancement continues to lead to smaller device geometries. Digital circuits have benefited from the technology scaling whereas analog circuits often suffer in terms of performance and noise immunity. As functionality continues to be integrated onto systems-on-chips, analog circuits consume increasingly more power than digital circuits and the objective of this Dissertation is to explore low power techniques in the context of both digital and analog circuits residing on the same silicon real estate.

As natural signals are in analog form, a necessity exists to convert these into digital form and then back again in order to exploit the …

Towards Analytical Techniques For Optimizing Knowledge Acquisition, Processing, Propagation, And Use In Cyberinfrastructure, Leonardo Octavio Lerma

Open Access Theses & Dissertations

For many decades, there has been a continuous progress in science and engineering applications.

A large part of this progress comes from the new knowledge that researchers acquire, propagate, and use. This new knowledge has revolutionized many aspects of our life, from driving to communications to shopping.

Somewhat surprisingly, there is one area of human activity which is the least impacted by the modern technological progress: the very processes of acquiring, processing, and propagating information. When we decide where to place sensors, which algorithm to use for processing the data – we rely mostly on our own intuition and on …

A Cell Formation Algorithm For Sequential Processes With Alternative Machine Selection In The Automotive Lighting Industry, Victor Manuel Loya Garnica

Open Access Theses & Dissertations

At the present time, there are more than 12 big companies dedicated to design and produce OEM lighting systems for cars and trucks. The manufacturing processes for headlamps, tail lamps and any other exterior vehicle lighting are very common in the auto industry. Still, every automotive lamp assembly is different from brand to brand and even between the different vehicle models. Indeed, there are car headlamps with less than 30 sub-components and others with up to 300 elements. This implies creating diverse part numbers which share or hold varying manufacturing methods within a specific facility. Management of the plant resources …

The Law Of Police, Richard H. Mcadams, Dhammika Dharmapala, Nuno Garoupa

Faculty Scholarship

Some Fourth Amendment doctrines distinguish between searches executed by police and others, being more demanding of the former. We explore these distinctions by offering a simple theory for how "police are different," focusing on self-selection. Those most attracted to the job of policing include those who feel the most intrinsic satisfaction from facilitating the punishment of wrongdoers. Thus, we expect police to have more intensely punitive preferences, on average, than the public or other governmental actors. Some experimental evidence supports this prediction. In turn, stronger punishment preferences logically lower one's threshold of doubt --the perceived probability of guilt at which …

A Methodology For Use Of Digital Image Correlation For Hot Mix Asphalt Testing, Estefany Ramos

Open Access Theses & Dissertations

Digital Image Correlation (DIC) is a relatively new technology which aids in the measurement of material properties without the need for installation of sensors. DIC is a noncontact measuring technique that requires the specimen to be marked with a random speckled pattern and to be photographed during the test. The photographs are then post-processed based on the location of the pattern throughout the test. DIC can aid in calculating properties that would otherwise be too difficult even with other measuring instruments.

The objective of this Thesis is to discuss the methodology and validate the use of DIC in different hot …

Reckless Anxiety, Hugo Esteban Rodriguez

Open Access Theses & Dissertations

Preface

SCOPE OF PROJECT

Reckless Anxiety will focus on fourteen short stories that have characters who all suffer from some form of mental illness, compulsion or disorder. The title is itself a paradox, because anxiety in its general sense could make someone with it more cautious than normal. I wanted to take it to an extreme level and approach writing with the recklessness of an artist afraid of what could happen should he ever stop moving or stop dancing.

PROJECT BACKGROUND

Before I started developing my Thesis, as a writer I felt as if I was on a path with …

Acoustic Emission Characteristics Of Damage Accumulation In Kevlar® 49 Composites, Eduardo Andrade

Open Access Theses & Dissertations

Acoustic emission (AE) data attained during tensile testing of epoxy impregnated Kevlar® 49 (K/Ep) composite strands were reduced and analyzed to monitor progressive damage accumulation during the approach to tensile failure. The K/Ep material tested in this study was chosen due to its similarity to the material-of-construction used in composite overwrapped pressure vessels (COPVs) used on the NASA Space Shuttle Orbiter. Insight into the progressive microstructural degradation of K/Ep strands was gained by monitoring AE event rate and energy. Source location based on energy attenuation and arrival time data was used to differentiate between significant AE attributable to microstructural damage …

Expired Patents, Saurabh Vishnubhakat

Faculty Scholarship

This article presents a comprehensive empirical description of the public domain of technologies that have recently passed out of patent protection. From a new dataset of over 300,000 patents that expired during 2008–2012, the study examines technological, geographical, and procedural traits of newly public inventions as a basis for exploring the social value associated with their competitive use. Moreover, comparing these inventions to inventions newly patented during the same period enables more specific discussion of how the balance of innovation in the United States continues to change.

Evaluating Methods Of Field-Based 3d Visualization And Their Application To Mapping Metamorphic Terranes: An Example From The Panamint Mountains, California, Jade Ashley Brush

Open Access Theses & Dissertations

Field geology has traditionally relied on 2D, paper-based workflows, but digital mapping techniques are rapidly replacing these outdated methods because they allow for more efficient and accurate mapping. This research applies digital mapping techniques and two terrestrially-based 3D visualization technologies, photogrammetry and Light Detection and Ranging (LiDAR), to the study of metamorphic terranes in the Panamint Mountains, California. This study reports on the spatial accuracy of TINs (triangulated irregular networks) generated from both photogrammetry and ground-based LiDAR using a terrestrial laser scanner (TLS) and discusses how spatial accuracy can be increased. Two levels of comparison were used to test spatial …

Aerosol Physical And Chemical Properties Over Tropical Atlantic Ocean, Elsa Castillo

Open Access Theses & Dissertations

The atmospheric aerosol mass size distributions, modal characteristics, and a comparative analysis of the characteristic of PM2.5 versus trace gases: CO, O3, and SO2 over tropical Atlantic Ocean have been evaluated for Nov-Dec 2013. This study took place during the IX AEROSE expedition while the National Oceanic and Atmospheric Administration (NOAA) research vessel Ronald H. Brown traveled south along 23°W between 3°N and 5°S.

Aerosol mass size distributions were measured directly with a California Instruments Model PC-2H Quartz Crystal Microbalance (QCM). The corresponding values of average mass for accumulation, nuclei and coarse mode obtained were: 0.00124±0.00077, 0.00506±0.00254, and 0.00176±0.00114 μg/m …

Novel Endohedral Derivatives Of Sc3n@C2n (N = 34, 40) And Unique Tether Controlled Bis-Functionalization Of Fullerenes, Maira Raquel Ceron Hernandez

Open Access Theses & Dissertations

Since the discovery of fullerenes in 1985, their exohedral functionalization has been necessary to increase their solubility and explore their properties and potential applications in materials science and medicinal chemistry. This Thesis provides a short overview of the importance of electronic, size and shape complementarity in determining the structures of specific endohedral fullerene compounds. This is followed by a description of a new method for the separation of scandium nitride endohedral fullerenes Sc3N@C2n (n = 34, 39 and 40), and their monofunctionalization.

We also present the regioselective synThesis of easily isolable bis-derivatives of C60, C70, and M3N@Ih-C80 (M = Sc, …

The Tigua Indians Of Ysleta Del Sur: A Borderlands Community, Scott C. Comar

Open Access Theses & Dissertations

This Dissertation offers a broad community history of the Tigua Indians of Ysleta del Sur Pueblo from colonial contact to their federal recognition in 1987. Considering Tigua history in a Borderlands context, it explores the interaction between community and identity. Here I argue that the Tiguas persisted through Spanish, Mexican, and American colonization because various identity markers involving place, interaction, and shared culture enhanced their community identity as an Indigenous people. This Dissertation also examines how social upheaval, migrations, and land dispossession impacted the Tiguas in various contexts, as well as some of the ways in which they adapted to …

Moisture Susceptibility Of Dense Graded Asphalt Concrete Using Cyclic Moistue Induced Stress Tester, Sarvesh Dip Dhakal

Open Access Theses & Dissertations

Moisture damage in asphalt concrete causes loss in mechanical properties of asphalt material due to the presence of moisture in its microstructures in a liquid or a vapor state. Some of the common types of distress observed in asphalt pavements due to moisture damage are stripping (separation of asphalt binder and aggregate), raveling (dislodgement of aggregate particles in asphalt mixture from surface), and hydraulic scour (a process that occurs on a saturated surface by which the pavement material is eroded due to dynamic action of tires in the presence of water). This Thesis focuses on the research on the effects …

Re-Examining Resistance: Fan-Produced Queer Readings And Teen Wolf, Joshua J. Espinoza

Open Access Theses & Dissertations

MTV's popular television series, Teen Wolf (2011), has amassed a large online following of fans that create their own queer narratives through fan-fiction, subverting the show's hegemonic heteronormativity. Through a textual thematic analysis of Teen Wolf, this case study illustrates how online fandoms can subvert hegemony through queer readings of literary characters, resisting the dominant heteronormativity on network television. This article argues that rearticulating the showâ??s narratives into queer readings functions as a form of LGBT resistance, effectively counteracting the heteronormativity and hegemony portrayed on screen. This study examines how Teen Wolf approaches queer content, including homoeroticism and LGBT themes …

Characterization Of The Nodamura Virus Rna Dependent Rna Polymerase And Formation Of Rna Replication Complexes In Mammalian Cells, Vincent Ulysses Gant

Open Access Theses & Dissertations

Positive-strand RNA viruses amplify their genomes in membrane-bound structures associated with intracellular membranes and organelles called replication complexes (RCs). Here, we begin to elucidate mechanisms of Nodamura virus (NoV; family Nodaviridae) RC assembly. The literature reports that NoV-infected muscle tissue exhibits mitochondrial aggregation and rearrangement of mitochondrial structure, leading to disorganization of the muscle fibrils. However, the molecular basis for this pathogenesis and the role of mitochondria in NoV infection remained unclear until now. We tested the hypoThesis that NoV establishes RCs in association with mitochondria in cultured mammalian cells at physiological temperature. We used immunofluorescence confocal microscopy and biochemical …

Transition States And Modeling For Co9s8/Mos2 Catalysis, Gabriel Angel Gonzalez

Open Access Theses & Dissertations

Transition state computational studies of the sulfur removal from dibenzothiophene (DBT) molecule have herein been performed considering the Co9S8/MoS2 interface existing on unsupported Co/MoS2 catalysts. The linear synchronous transit (LST) and quadratic synchronous transit (QST) methods integrated in a density functional theory (DFT) program such as Dmol3 were used for the calculations of energy barriers of the transition states. Three different configurations present on the Co9S8/MoS2 interface have been envisaged as possible catalytic sites: sulfur-sulfur (S, S) sites, and molybdenum-sulfur (Mo, S) and molybdenum-molybdenum (Mo, Mo) edge sites. This study revealed that the (Mo, Mo) edge site is the most …

Borderland Pedagogy Study Of High School Mathematics Teachers' Lesson Plan Development And Implementation Practices, Rocio E. Gallardo

Open Access Theses & Dissertations

The aim of the study is to examine high school mathematics teachers' lesson plan development and implementation practices used in the border region of Mexico and USA. The study also attempts to determine how a transition from Mexico (Ciudad Juarez, Chihuahua) to the U.S. (El Paso, TX) impacts high school mathematics teacher's lesson plan development practices incorporating the Borderland Pedagogy. The Borderland Pedagogy theoretical framework (Cline & Necochea, 2006; Romo & Chavez 2006; Fiume, 2005) was developed to explore educational experiences of teachers situated within border regions. The framework highlights key characteristics of Borderland Pedagogy that influence lesson plan development …

Effect Of Plastic Deformation Anisotropies On Shock-Induced Phase Transitions In Metallic Single Crystals, Punam Ghimire

Open Access Theses & Dissertations

Most metals and alloys undergo plastic deformation at shear stresses and/or pressures in the Kbars regime. On the other hand, typical pressure-induced structural transitions, take place at much higher pressures, in the tens of GPa range. Surprisingly, there has not been to date, a systematic study on the role plastic deformation plays on the dynamics of defect-mediated phase transformations. The main purpose of this work was to investigate via atomistic simulations, the contribution of pre-existing defect densities on the kinetics of structural transformations under dynamic loading. We have carried out molecular dynamics simulations - including large-scale non-equilibrium molecular dynamics (NEMD), …

High Temperature Helical Tubular Receiver For Concentrating Solar Power System, Nazmul Hossain

Open Access Theses & Dissertations

In the field of conventional cleaner power generation technology, concentrating solar power systems have introduced remarkable opportunity. In a solar power tower, solar energy concentrated by the heliostats at a single point produces very high temperature. Falling solid particles or heat transfer fluid passing through that high temperature region absorbs heat to generate electricity. Increasing the residence time will result in more heat gain and increase efficiency. A novel design of solar receiver for both fluid and solid particle is approached in this paper which can increase residence time resulting in higher temperature gain in one cycle compared to conventional …

Wind Farm Optimization Using Evolutionary Algorithms, Carlos Marco Ituarte-Villarreal

Open Access Theses & Dissertations

In recent years, the wind power industry has focused its efforts on solving the Wind Farm Layout Optimization (WFLO) problem. Wind resource assessment is a pivotal step in optimizing the wind-farm design and siting and, in determining whether a project is economically feasible or not. In the present work, three (3) different optimization methods are proposed for the solution of the WFLO: (i) A modified Viral System Algorithm applied to the optimization of the proper location of the components in a wind-farm to maximize the energy output given a stated wind environment of the site. The optimization problem is formulated …

Design Of A High Intensity Turbulent Combustion System, Mohammad Arif Hossain

Open Access Theses & Dissertations

In order to design next generation gas turbine combustor and rocket engines, a systematic study of flame structure at high intensity turbulent flow is necessary. The fundamental study of turbulent premixed combustion has been a major research concern for decades. The work is focused on the design and development of a high intensity turbulent combustion system which can be operated at compressible (0.3 < M < 0.5), preheated (T0=500K) and premixed conditions in order to investigate the 'Thickened Flame' regime. An air-methane mixture has been used as the fuel for this study. An optically accessible backward-facing step stabilized combustor has been designed for a maximum operating pressure of 6 bar. A grid has been introduced with different blockage ratios (BR = 54%, 61% & 67%) in order to generate turbulence inside the combustor for the experiment. Optical access is provided via quartz windows on three sides of the combustion chamber. Finite Element Analysis (FEA) is done in order to verify the structural integrity of the combustor at rated conditions. In order to increase the inlet temperature of the air, a heating section was designed to use commercially available in-line heaters. Separate cooling subsystems have been designed for chamber cooling and exhaust cooling. The LabVIEW software interface has been selected as the control mechanism for the experimental setup. A 10 kHz Time Resolved Particle Image Velocimetry (TR-PIV) system and a 3 kHz Planer Laser Induced Fluorescence (PLIF) system have been integrated with the system in order to diagnose the flow field and the flame respectively. The primary understanding of the flow field inside the combustor was achieved through the use of Detached Eddy Simulation (DES) by using commercially available software package ANSYS FLUENT. Preliminary validation is done by 10 kHz TR-PIV technique. Both qualitative and quantitative analysis have been done for CFD and experiment. Major flow parameters such as average velocity, fluctuation of velocity, kinetic energy, and turbulent intensity have been calculated for two distinct Reynolds number (Re = 815 & 3500). PIV results are compared with CFD results which show significant agreement with each other.

Design Of Screening System For Transatlantic Container Transport, Michal Jizba

Open Access Theses & Dissertations

Maritime container transport plays a major role in international trade. As such, it can be an attractive target of acts of unlawful interference, e.g., smuggling, piracy or terrorism. One major issue of maritime security is the container screening at ports, which is the main focus of this Thesis. The goal of this Thesis is to study the efficiency of different designs of screening systems using simulation. The literature review covers contemporary laws and requirements, container screening equipment and processes related to screening that take place in seaports. Next, operation of three screening checkpoints models, which symbolize predominant approaches to container …

Thermal Shock Studies On Carbon-Carbon Composites: Experimentation And Analysis, Alma Lucia Leanos

Open Access Theses & Dissertations

The oxidation behavior of C/C composites under thermal shock conditions in air is understood and predicted experimentally and by computational efforts. In Chapter. 1, both compressive properties and oxidation behavior of pristine and thermal shock exposed 2D C/C composite specimens were examined. Pristine test specimens were exposed to thermal shock conditions with temperatures ranging from 400°C to 1000°C in an oxidizing environment, followed by compression tests on pristine and thermal shock exposed specimens to obtain their compressive responses.

Similarly, in Chapter. 2, the influence of thermal shock conditions on both, the extent of carbon materials decomposition and the through-thickness compressive …

Simulation Of Infiltrating Rate Driven By Surface Tension-Viscosity Of Liquid Elements From The Titanium Group Into A Packed Bed, Arturo Medina

Open Access Theses & Dissertations

The simulation of infusion of molten reactive metals (e.g., yttrium) into a porous, carbide packed bed to create carbide and boride composites was studied at ultrahigh temperatures (>1700°C). The infusion was investigated through a computational fluid dynamic (CFD) system of capillary pores and compared to a predicted analytical calculation formulated by Selmak and Rhines. Simulations of two-phase flow penetration of yttrium into a packed bed of B4C were investigated and compared with titanium, zirconium, hafnium, and samarium liquids. The non-reactive, liquid metal infusion was primarily driven by the surface tension and viscosity. The liquid metal depth and rate of …

Receiver Function Analysis To Study Crustal Structure Of The Northern Nepal And Tibetan Plateau, Mohan Pant

Open Access Theses & Dissertations

The teleseismic P-waveform receiver function analysis is a commonly used technique in earthquake seismology to study the crustal structure beneath a broadband seismic station. To understand the structure of the Northern Nepal and Tibetan plateau different studies have used the receiver function method to estimate the Moho depth and Vp/Vs ratio. The value suggested was ~ 30 km in the south and the ~ 75 km in the north. Other studies have used teleseismic body wave data to perform the travel time residuals to model the lithosphere structure. In our study, we analyzed data from 261 seismic stations to establish …

Effect Of Si Substrate Orientation On The Quality Of Cdte Selective Growth On Si(111) And Si(211) Substrates Via Closed-Space Sublimation (Css) Witout The Use Of A Mask., Aryzbe Najera

Open Access Theses & Dissertations

The material, fabrication and operation parameters for mercury cadmium telluride (HgCdTe) detectors require high sensitivity, small pixel size, low defect density, long-term thermal-cycling reliability and large area substrates. The focus of this work is on the epitaxial growth of CdTe thin films on Si(111) and Si(211) for the purpose of using the resulting material as a substrate for the subsequent growth of HgCdTe thin films. Currently, there is an interest to improve the quality of epitaxial thin films associated with the fabrication of HgCdTe infrared and X-ray imaging using the close-spaced sublimation (CSS) technique. The CSS technique is proven to …

Synchronization Of Bistatic Radar Using Chaotic Amplitude And Frequency Modulated Signals, Chandra Sekhar Pappu

Open Access Theses & Dissertations

The purpose of this work is to develop a synchronization scheme for bistatic radar that uses a 3-D chaotic system to generate and process wideband AM and FM signals, which allows for the extraction of high range-resolution information from targets. For AM bistatic radar, the setup includes a drive oscillator at the transmitter and a response oscillator at the receiver. The challenge is synchronizing the response oscillator to the drive oscillator with a scaled version of the transmitted signal sr(t, x) = αs t(t, x), where x is a chaotic state variable and α is a scaling factor. Here, α …

Ac-Susceptibility And Epr Investigations Of Superspin Dynamics In Magnetite Nanoparticles, Alex D. Price

Open Access Theses & Dissertations

In this investigation we use two complementary techniques to distinguish between superparamagnetic blocking (SPB) and superspin-glass (SSG) freezing phenomena in magnetite nanoparticles. While these manifestations of the superspin dynamics are fundamentally different, they have similar "signatures", especially in dc-magnetization experiments. Even if ac-susceptibility measurements are employed, careful use of mathematical models to analyze the data are needed to uncover which type of phenomena (SPB or SSG freezing) occurs within the material. Yet, by utilizing electron paramagnetic resonance (EPR) on a 10 nm Fe3O4 nano-powder as well as on a ferrofluid (based on the same nanoparticle ensemble) we found a very …

Fluid Flow Characterization Of High Turbulent Intensity Compressible Flow Using Particle Image Velocimetry, Marco Efrain Quiroz

Open Access Theses & Dissertations

A high turbulent intensity combustion chamber has been designed in order to operate with compressible (0.3 < M < 0.5) and preheated (T=500K) air-methane combustion. These conditions will allow the investigation of different flame regimes; most notably the proposed "Thickened Flame" regime. Initial design and flow validation has been completed in order to begin further experimentation. A 10 kHz Time Resolved Particle Image Velocimetry (TR-PIV) system and a 3 kHz Planer Laser Induced Fluorescence (PLIF) system have been integrated with the system in order to diagnose the flow field and the flame respectively. The exhaust and chamber cooling subsystems were designed to comply with safety regulations, and the control systems were set up in a way that allows automated (LabVIEW) and user controlled sequencing. This work's main purpose is to characterize and map the flow properties at maximum flow conditions (M > 0.3) in order to map the following; flow structures, kinetic energy at different length scales, velocity fluctuations and turbulent intensity. PIV measurements are carried out for three different volumetric flow rates (ð???Ì? = 25 scfm, 55 scfm, and 115 scfm) and three different grid geometries for each (BR= 67%, 61%, and 54%). Upon finding that the main flow structure consisted of jets caused by the grid at higher flowrates, experiments were done with a grid BR = 67% which was thinner (50% of original …

Comic Book Fandom: An Exploratory Study Into The World Of Comic Book Fan Social Identity Through Parasocial Theory, Anthony Robert Ramirez

Open Access Theses & Dissertations

Comic books and their extensive lineup of characters have invaded all types of media forms, making comics a global media phenomenon that are having a wider profile in media and popular culture. The community of comic book fans has grown as well. The purpose of this study is to investigate how these fans identify with their favorite comic book character(s) through the application of parasocial theory, in order to discover if and how various identification levels lead to the fan's level of fandom or attachment. Various fans of comic books are interviewed, in order to investigate attachment levels and level …