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Detailed Analysis Of Convective Simulations From A Wrf Microphysics Ensemble, Joshua Markel

Theses and Dissertations

This study performed a detailed analysis of convective storms across the Contiguous United States from 77 case dates using a 4-member microphysics Weather Research and Forecasting (WRF) ensemble and Stage IV gauge-adjusted radar derived precipitation. Dates included the 2016 NOAA Spring Forecast Experiment (SFE) with the remainder from 2010-2012. Quantitative attributes of precipitation objects in both simulations and observations were diagnosed using the Method of Object-Based Diagnostic Evaluation Time-Domain (MODE-TD). The microphysics schemes tested were WSM6, Thompson, Morrison, and Milbrandt.

Among all simulation case dates, compared to observations, the number of precipitation objects less than 90 km in length are …

Spacesuit Integrated Carbon Nanotube Dust Mitigation System For Lunar Exploration, Kavya Kamal Manyapu

Theses and Dissertations

Lunar dust proved to be troublesome during the Apollo missions. The lunar dust comprises of fine particles, with electric charges imparted by solar winds and ultraviolet radiation. As such, it adheres readily, and easily penetrates through smallest crevices into mechanisms. During Apollo missions, the powdery dust substantially degraded the performance of spacesuits by abrading suit fabric and clogging seals. Dust also degraded other critical equipment such as rovers, thermal control and optical surfaces, solar arrays, and was thus shown to be a major issue for surface operations. Even inside the lunar module, Apollo astronauts were exposed to this dust when …

Lightcurve Study Of V-Type Asteroids, Matt Nowinski

Theses and Dissertations

A massive impact event on (4) Vesta is believed to have created the Vesta family of asteroids (Asphaug, 1997). The rotational characteristics of the Vesta family provide important clues about this event, including its timing, the make-up of the resulting debris, the subsequent migration of members of the family into Earth-crossing orbits, and the deposition of the Howardite-Eucrite-Diogenite meteorites on the Earth’s surface. This study conducted lightcurve measurements of ten Vp-type asteroids, drawn from an asteroid taxonomy defined by Carvano et al. (2010) and based on the Sloan Digital Sky Survey (SDSS) Moving Object Catalogue (MOC4). These measurements identified a …

Optimal Control Of Induction Machines To Minimize Transient Energy Losses, Siby Jose Plathottam

Theses and Dissertations

Induction machines are electromechanical energy conversion devices comprised of a stator and a rotor. Torque is generated due to the interaction between the rotating magnetic field from the stator, and the current induced in the rotor conductors. Their speed and torque output can be precisely controlled by manipulating the magnitude, frequency, and phase of the three input sinusoidal voltage waveforms. Their ruggedness, low cost, and high efficiency have made them ubiquitous component of nearly every industrial application. Thus, even a small improvement in their energy efficient tend to give a large amount of electrical energy savings over the lifetime of …

An Investigation Of The Thermal Degradation Of Lignin, Sara Pourjafar

Theses and Dissertations

The goal of this research was to explore selected non-biological lignin decomposition reactions to determine if these reactions have the potential to generate fuel and chemical intermediates in a commercially feasible manner. Two different strategies were employed: 1) metal doped silica-alumina and γ-alumina catalytic decomposition reactions, and 2) base catalyzed sub- and supercritical water liquefaction.

The first strategy was built upon previous research to explore metal doped silica-alumina and γ-alumina catalytic lignin decomposition reactions in a batch reactor system. Commercially available silica-alumina and γ-alumina catalysts were individually doped with 5 and 10 wt % of molybdenum or copper via a …

The Effects Of Subject Presentation Types In Problem Based Learning (Pbl) Problems On Student Motivation: A Pbl Implementation In Speech Language Pathology, Elaine Kim Pyle

Theses and Dissertations

Problem-Based Learning (PBL) is an evidence-based instructional approach designed to maximize one’s ability to use static knowledge as evidence for solving authentic problems (Barrows, 1986). Students have been observed as underprepared or skipping steps during the PBL process due to fatigue or low motivation (Czabanowska, Moust, Meijer, Schr��-B夫, & Robertson, 2012). This study considered the impact of the presentation of the PBL subject (i.e., the key character involved in the problem) on student motivation within the context of Speech and Voice Science curricula. The results of this mixed-methods study showed the frequency of engagement behaviors declined overall. Although engagement levels …

Design And Manufacture Of A Negative Index Metamaterial Using A Magnetized Photonic Crystal, Mohamed Zein Radwan

Theses and Dissertations

Negative index materials (NIM) are artificial structures in which the refractive index for light has a negative value over some frequency range. This does not occur in any known natural materials, and thus is only achievable with engineered structures known as metamaterials. Metamaterials demonstrating a negative refractive index for light usually consist of arrays of wires and cut-ring structures: such media are characterized by both the electrical permittivity and magnetic permeability being negative. My method for obtaining a NIM is different from previous attempts. I get the negative magnetic permeability from a ferrite material which is the host medium for …

Modeling The Interactions Between Turbulence And Radiation In Oxy-Combustion Flames, Md Ashiqur Rahman

Theses and Dissertations

In order to accurately estimate radiative heat transfer in turbulent combustion systems, one needs to take into account the non-linear interactions between the temporally fluctuating species and temperature variables and the radiation field. Simply employing time-averaged values of these variables in the radiation calculations to estimate absorption and emission (as is commonly done in the modeling community) can result in gross errors in the estimation of the radiative fluxes. Therefore, models that account for these Turbulence-Radiation Interactions (TRI) have been proposed in the literature to improve the fidelity of the radiative transfer calculations. TRI models accomplish this by computing appropriate …

Effects Of Non-Conventional Gas And Oil Production Activities On Local And Regional Fine Particles And Ground-Level Ozone, Swetha Mallula

Theses and Dissertations

Unconventional oil and gas production in North Dakota and Texas has been rising significantly since 2007 with the advances in hydraulic fracturing technology. The effects of unconventional oil and gas production on the environmental quality and public health, however, are not well understood. The goal of this study was to investigate the effects of unconventional energy production on two types of air pollutants (fine particles and ground-level ozone). We analyzed the air quality data from publicly accessible sources, focusing on two major oil producing states (North Dakota, Texas) and two control states (Minnesota and Connecticut). The specific objectives of this …

Simulating Boundary Crossing Supercells Using A Non-Hydrostatic Cloud Model, Aaron Keith Scott

Theses and Dissertations

Supercell thunderstorms are among nature’s most powerful phenomena. Particular environmental conditions are strongly correlated with peak supercell and tornado strength. However, supercells may experience changes within the near-storm environment during their lifecycle. For example, a storm may cross a preexisting outflow boundary from previous convection; thus, the storm will experience changes in the environmental thermodynamic and wind profiles. The purpose of this study is to determine what happens to the low-level mesocyclone immediately after crossing a boundary, analyze storm sensitivity to differing boundary crossing times, and show how the vorticity processes change as a storm moves from one environment to …

Enhanced Optical Wireless Channel For Indoor And Intravehicle Communications: Power Distribution And Signal To Noise Ratio Analysis, Rana Rageh Shaaban

Theses and Dissertations

Visible light communication—(VLC) provides wide bandwidth and high security

capabilities for free space optical communication. This thesis presents the key concepts,

underlying principles and practical applications of visible light communications. In

particular, this thesis focuses on the received power distribution pattern and signal to noise

ratio for line-of-sight indoor and vehicular applications. Several methods are used to

modify the SNR and power distribution levels. It is shown that in the absence of

obstruction, the optical footprint is nearly circular and offers a platform for large- scale

deployment in commercial environments, which is similar to micro and Pico cells.

By studying …

Testing An Integrative Model Of Depressive Symptoms With A Sample Of Latina/O Youth, Diana Slivensky

Theses and Dissertations

Latina/o youth represent a significant portion of the United States population and experience depressive symptoms at greater rates than other racial and ethnic groups. Prior research has found relationships between the cultural adaptation process and negative

mental health outcomes. The purpose of the present study was to test a model of depressive symptoms with a sample of Latina/o youth that aimed to explore the relations among acculturation, enculturation, bicultural stress, adherence to cultural values (i.e., familismo and respeto), family cohesion, and perceived peer support. Additionally, the present study examined gender differences among all the aforesaid variables. Participants included 156 Latina/o …

Inner Strength In Men-A Descriptive Phenomenology, Charles S. Smith

Theses and Dissertations

The purpose of this descriptive phenomenologic study was to explicate the eidetic structure and essence of inner strength in men. Based in the philosophy of Husserl (2012) and developed from the methodology of Giorgi (2009), inner strength in men emerged as a unique phenomenon comprised of five structural themes: 1) mentally managing; 2) purposefully moving; 3) intentional normalizing; 4) intentional connecting; and, 5) mobilizing self to get through. The essence of inner strength in men was “purposefully moving ‘through a glass darkly’ to get to the other side.”

Twelve men aged 50 years or older (m = 60.25 years) shared …

Inner Strength In Mothers Of Children With Autism Spectrum Disorders: Oral Histories, Jennifer Weathersbee Steinberg

Theses and Dissertations

The purpose of this oral history study was to describe the lived experiences of mothers of children diagnosed with autism spectrum disorders (ASD) and to further inform the Theory of Inner Strength in Women (TIS) (Dingley & Roux, 2014). Postmodern feminist oral history methods were used to answer the research questions which included: 1) What are the lived experiences of mothers of children diagnosed with autism spectrum disorder (ASD)? and 2) How do these experiences further inform TIS?

Interviews were manually coded directly onto the digital audio files using NVivo11Plus qualitative data management software. Three chronologic phases were identified among …

A Comprehensive Analysis Of Clouds, Radiation, And Precipitation In The North Pacific Itcz In The Nasa Giss Modele Gcm And Satellite Observations, Ryan Evan Stanfield

Theses and Dissertations

Global circulation/climate models (GCMs) remain as an invaluable tool to predict future potential climate change. To best advise policy makers, assessing and increasing the accuracy of climate models is paramount. The treatment of clouds, radiation and precipitation in climate models and their associated feedbacks have long been one of the largest sources of uncertainty in predicting any potential future climate changes.

Three versions of the NASA GISS ModelE GCM (the frozen CMIP5 version [C5], a post-CMIP5 version with modifications to cumulus and boundary layer turbulence parameterizations [P5], and the most recent version of the GCM which builds on the post-CMIP5 …

Outcrop Mapping Using Unmanned Aerial Systems And Modeling Of The Shannon Sandstone In The Powder River Basin, Emily Grace Sundell

Theses and Dissertations

Mapping steep outcrops by hand is dangerous, time consuming and gathering images parallel to a cliff face is difficult to nearly impossible. Wyoming has many extensive, steep, surface outcrops that in the subsurface are petroleum-producing formations. The Powder River Basin (PRB) of Wyoming has been a prolific producer of petroleum since the late 1800s, and with continual advances in technology production continues to increase. During the Cretaceous, the PRB was inundated by the Western Interior Seaway. Sand-clay sequences corresponding to transgressions and regressions were deposited and resulted in the Campanian Shannon Member of the Cody Formation. The Shannon Member thickens …

Epigenetic Remodeling As A Mediator Of Environmental Toxicant Exposure In The Brain, Christopher David Walden

Theses and Dissertations

Natural toxins and artificial toxicants are abundant throughout our environment and may play an integral role in remodeling our epigenome and in the development of neural diseases. Exposure to heavy metals and organic pollutants, such as DDT and its derivatives, have been linked to neural disease. Additionally, there are links between direct exposure, in both adults and children, to short-lived pesticides and neural diseases. While the link has been established, understanding the root cause has yet to be elucidated. One increasingly relevant field offering promise in achieving this goal is epigenetics. Epigenetic remodeling is one potential mechanism by which environmental …

A Survey Measuring The Efficacy Of Duty And Rest Guidelines In Business Aviation Operations, Timothy Wollmuth

Theses and Dissertations

Despite improved understanding of fatigue, reduced cognitive ability continues to contribute to aviation accidents (Drury, Ferguson, & Thomas, 2012; Noy et al., 2011). A comprehensive fatigue study on business aviation (BA) operations in the US has not been published since "Crew Factors in Flight Operations XIII: A Survey of Fatigue Factors in Corporate/Executive Aviation Operations" (Rosekind, Co, Gregory, & Miller, 2000). This study, modeled after the Rosekind survey and conducted in collaboration with the National Business Aviation Association (NBAA), updated the baseline for fatigue in BA, qualitatively examined fatigue perceptions in BA, and examined the efficacy of the “Flight Safety …

Parents Of Adolescent Children With Mental Illness: A Qualitative Exploration Of The Lived Experience, Lindsay Yates

Theses and Dissertations

The current exploratory study aimed to understand the experience of parents whose children have severe and persistent mental illness. It was hypothesized that themes developed from parents’ responses to interview questions would indicate the presence of a) grief, b) trauma, c) subjective burden, and d) objective burden. Participants were 13 parents, comprised of conveniently sampled biological parents and legal guardians. Each parent was independently interviewed using a semi-structured protocol. Interviews were audio recorded and transcribed by the principal investigator. Transcripts were analyzed using consensual qualitative analysis. An in-depth analysis of each transcript and cross analysis of transcripts yielded seven domains: …

A Radioelement Analysis Of The Northern Black Hills, South Dakota, U.S.A., Dylan Wade Young

Theses and Dissertations

The uranium, thorium, and potassium contents from 736 samples, within a 15-km radius of the Homestake Gold Mine and Sanford Underground Research Facility in the Northern Black Hills indicate the geoneutrino background may be higher than average for the continental crust. The radioactive element contents of igneous, metamorphic, and sedimentary rocks were determined by gamma ray spectrometry. Many rocks show hydrothermal and metamorphic alteration within the last ten Ma of the Tertiary period. Young alkali rich igneous rocks, such as rhyolite, phonolite and other volcanic rocks, have lower than average Th:U ratios. The radioelement content of 215 igneous rocks were …

A Study Of Scattering From Snow Embedded With Non-Spherical Shapes Of Scatterers With Relaxed Hierarchical Equivalent Source Algorithm (Rhesa), Chan Fai Lum, Fu Xin, Hong Tat Ewe, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Remote sensing has been used widely in studying the earth terrain such as snow or sea ice due to its fast, convenient and long-term monitoring capabilities. SAR images acquired could be used to analyze the condition of snow, snow water equivalent (SWE), surface roughness and others. Theoretical models have also been developed to understand how microwave interacts with the snow medium and the scatterers embedded inside the medium. Conventionally, spherical shape of scatterers is commonly used to represent the ice particles embedded inside snow where the actual shape of scatterers can vary. This paper is to present a theoretical model …

Decentralized Fault Diagnosis And Prognosis Scheme For Interconnected Nonlinear Discrete-Time Systems, Hasan Ferdowsi, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This paper deals with the design of a decentralized fault diagnosis and prognosis scheme for interconnected nonlinear discrete-time systems which are modelled as the interconnection of several subsystems. For each subsystem, a local fault detector (LFD) is designed based on the dynamic model of the local subsystem and the local states. Each LFD consists of an observer with an online neural network (NN)-based approximator. The online NN approximators only use local measurements as their inputs, and are always turned on and continuously learn the interconnection as well as possible fault function. A fault is detected by comparing the output of …

Vehicle Base Station, Emad William Saad, J. L. Vian, Matthew A. Vavrina, J. A. Nisbett, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

A system to load and unload material from a vehicle comprises a vehicle base station and an assembly to autonomously load and unload material from the vehicle.

A Collimated Surface-Wave-Excited High-Impedance Surface Leaky-Wave Antenna, Zi Long Ma, Chi Hou Chan, Kung Bo Ng, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This letter presents a novel high-impedance surface (HIS)-based leaky-wave antenna excited by collimated surface wave (SW). The proposed antenna consists of two identical SW launchers (SWLs) and an HIS structure. Regarding the SWL, it is based on an offset-fed parabolic reflector. By using the substrate-integrated waveguide technique, the reflector system is integrated in the planar substrate. For the HIS, it is formed by a periodically arranged rectangular microstrip patch array. The proposed SWL can generate collimated SW with the propagation mode. With the perturbation of the HIS, the guided SW can be transformed to m = -1 space-harmonic-mode leaky wave. …

Low Frequency Behavior Of Cvd Graphene From Dc To 40 Ghz, Rong Wang, Salahuddin Raju, Mansun Chan, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic behaviour of chemical vapor deposition (CVD) graphene at low frequencies is still a mystery. No conclusion is made from the experimental point of views. We systematically investigate the electromagnetic response of graphene at microwave frequencies, which are from direct current (DC) to 40 GHz. Both a coplanar transmission line embedded with different-sized graphene flakes of 48 x 48 and 48 x 240 μm2 and a microwave termination based on the graphene sheet of 6 x 6mm2 are manufactured through standard microfabrication procedures. We conclude that CVD graphene behaves as a frequency-independent surface resistance at the microwave frequencies, which is …

Volterra Series-Based Time-Domain Macromodeling Of Nonlinear Circuits, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Jose E. Schutt-Aine, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

Volterra series (VS) representation is a powerful mathematical model for nonlinear circuits. However, the difficulties in determining higher order Volterra kernels limited its broader applications. In this paper, a systematic approach that enables a convenient extraction of Volterra kernels from X-parameters is presented. A concise and general representation of the output response due to arbitrary number of input tones is given. The relationship between Volterra kernels and X-parameters is explicitly formulated. An efficient frequency sweep scheme and an output frequency indexing scheme are provided. The least square linear regression method is employed to separate different orders of Volterra kernels at …

Robust Airfoil Design Optimization Using Stochastic Expansions And Utility Theory, Xiaosong Du, Leifur Leifsson, Slawomir Koziel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Efficient and effective robust airfoil design optimization is proposed by integrating stochastic expansions and utility theory. In this work, the stochastic expansions are generated efficiently using non-intrusive polynomial chaos (NIPC) expansions. The robust design problem is formulated using utility functions which transfer a targeted response using a prescribed mathematical function to represent the designers' risk preferences. The proposed approach is demonstrated using examples of lift-constrained airfoil drag minimization in transonic viscous flow using the Mach number as an uncertain variable in the range of 0.70 to 0.75. The results are compared with the common problem formulation for robust design of …

Equators Have At Most Countable Many Singularities With Bounded Total Angle, Pilar Herreros, Mario Ponce, J.J.P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

For distinct points p and q in a two-dimensional Riemannian manifold, one defines their mediatrix Lpq as the set of equidistant points to p and q. It is known that mediatrices have a cell decomposition consisting of a finite number of branch points connected by Lipschitz curves. In the case of a topological sphere, mediatrices are called equators and it can benoticed that there are no branching points, thus an equator is a topological circle with possibly many Lipschitz singularities. This paper establishes that mediatrices have the radial …

Parental Input To Children With Asd And Its Influence On Later Language, Aparna Nadig, Janet Bang

Faculty Research, Scholarly, and Creative Activity

In this chapter, we review evidence on parental input to children with autism spectrum disorder (ASD), moving from quantitative measures of linguistic features to qualitative measures of interaction. First, we examine lexical and syntactic features (e.g., number of utterances, mean length of utterance [MLU]) in the input provided to children with ASD compared with TD [typically developing] children matched on language level. Second, we turn to work on parental responsiveness, or the tendency to provide verbal or gestural input in sync with the child’s focus of attention, and how this compares across dyads including a child with ASD or a …

Pedagod: God As Teacher, Avner Segall, Scott Jarvie

Faculty Research, Scholarly, and Creative Activity

No abstract provided.