Digital Commons Network^™

Influence Of Limestone Powder Content And Size On Transport Properties Of Self-Consolidating Concrete, Rebecca Kendal Spitek

UNLV Theses, Dissertations, Professional Papers, and Capstones

Self-consolidating concrete (SCC) requires higher cementitious materials content than conventional vibratory-placed concrete. This requirement leads to higher time-dependent properties (i.e., shrinkage (drying and autogeneous) and creep), increases formwork pressure, and results in a higher production cost. One alternative to alleviate excess creep and shrinkage, and to reduce cost, is to replace a portion of cementitious materials with mineral additives. The objective of this study was to examine the role of limestone powder, as a partial replacement of cementitious materials, on transport properties of self-consolidating concrete (SCC). A total of 10 different SCCs, including a control concrete, was prepared and test …

Post-Occupancy Energy Efficiency Evaluation Of A Leed Platinum Federal Government Facility, Theresa Tincher

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to gain a comprehensive understanding of the Leadership in Energy and Environmental Design (LEED®) certification system and its relevance to Federal policies, building codes, and building standards, develop experience with whole building energy modeling, and determine the actual post-occupancy energy usage as compared with developed model and design projections. This thesis hypothesized the U.S. Green Building Council's LEED rating system compared favorably to other policies, codes, and standards in use at the time, and the U.S. Bureau of Reclamations' LEED Platinum Lower Colorado Regional Office Green Building (LCROGB), located in Boulder City, Nevada, operated …

Simulations Of Interfacial Electrokinetics With Applications To Microfluidic Systems, Sebastian Uppapalli

UNLV Theses, Dissertations, Professional Papers, and Capstones

Electrokinetics plays an important role in facilitating fluid transport and particle manipulation in microfluidic systems. This dissertation studies the mechanics of electrokinetic phenomena for microscale particles and drops. The work aims to increase the understanding of complex electrokinetic phenomena for applications in Lab-on-Chip technology, assembly of colloidal particles and two-phase flow sensing. The standard model consisting of the Poisson-Nernst-Planck equations is used to study the electric double layer polarization of charged dielectric particles and channel wall which plays a major role in control and manipulation of colloidal particles and understanding of electrohydrodynamic flow field.

The cases of polarization of "soft" …

Life History Tradeoffs And The Costs Of Reproduction In Arizona Bark Scorpions (Centruroides Sculpturatus), Michael Marie Webber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tradeoffs in life history evolution result from conflicts in the time and energy that can be simultaneously invested in activities such as growth, reproduction, and survival. Reproduction is an energetically costly activity for organisms, and is known to elicit alterations in the daily activity patterns of individuals. I investigated reproductive tradeoffs in the Arizona Bark Scorpion,Centruroides sculpturatus. To better understand the nature of tradeoffs in this species, I examined the influence of reproductive state on the predatory efficiency and thermal preference of reproductive females. Further, I examined the influence of reproductive activities (i.e. gestation) on the ability of reproductive females …

Development Of A Molecular Method For Detecting The Causative Agent Of Swimmer's Itch (Trichobilharzia) In Freshwater Ecosystems, Heidi Mcmaster

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cercarial dermatitis, commonly known as swimmer's itch, is caused by penetration of larvae of the schistosome,Trichobilharzia, into the dermis and epidermis layers of the skin. Symptoms are characterized by painful swelling and itching at the site of penetration. The normal hosts for the life cycle of the schistosome are aquatic birds and aquatic snails. The most frequently used method of detection forTrichobilharziais microscopy. With increases in the occurrence of cercarial dermatitis outbreaks in freshwater in the Southwestern United States, it is becoming increasingly important to develop and standardize a molecular method for rapid detection that can assist health professionals and …

N-Dimensional Quasipolar Coordinates - Theory And Application, Tan Mai Nguyen

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, various generalizations to the n-dimension of the polar coordinates and spherical coordinates are introduced and compared with each other and the existent ones in the literature. The proof of the Jacobian of these coordinates is very often wrongfully claimed. Currently, prior to our proof, there are only two complete proofs of the Jacobian of these coordinates known to us. A friendlier definition of these coordinates is introduced and an original, direct, short, and elementary proof of the Jacobian of these coordinates is given. A method, which we call a perturbative (not perturbation) method, is introduced so that …

Determinants Of Head And Neck Cancer Survival In Nevada For 1995-2008, Xiao Q. Li

UNLV Theses, Dissertations, Professional Papers, and Capstones

Head and neck cancer (HNC), also known as oral cavity and pharyngeal cancer, comprises a group of cancers that arise in the head or neck region, such as the nasal cavity, sinuses, lips, mouth, salivary glands, and pharynx. Use of tobacco, alcohol, or a combination of the two, are major risk factors for head and neck cancer. Approximately 75% of oral cancers are attributable to smoking and/or alcohol consumption. More recently, the human papilloma virus (HPV) has also been associated with the development of head and neck cancer.

The objective of the present study is to investigate head and neck …

Family Environment And Severity Of Absenteeism In Youth, Rachel Marie Loftis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The current study examined the relationship between family environment and severity of youth absenteeism in clinical and community settings. Previous researchers have adopted a categorical approach to investigating the role of family environment in problematic absenteeism by diving youth into discrete categories and these studies are almost exclusively conducted in clinical settings. The current study contributes to the literature by adopting a dimensional approach that examines the impact of family environment on problematic absenteeism across diagnostic and functional categories.

The first aim of the study was to determine the family environment characteristics most predictive of absenteeism severity. The first hypothesis …

High Stakes Of Media Messages: Decoding Visual Narratives From The Iraq War In The U.S. And British Presses, Jennifer Liese

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research analyzes media coverage of the Iraq War from the perspective of the invading forces, the United States and the United Kingdom. The New York Times and The Guardian were chosen to represent news from their respective countries because of their high circulation rates and international prestige for journalistic reporting. The study focuses on how the Iraq War was visually represented after the Iraq invasion of 2003, examining periods in 2006 and 2011. There were significant differences in how The New York Times and The Guardian visually portrayed the war in 2006, especially in terms of Iraqi civilian and …

Numerical Study Of A Novel Fin Configuration Of A High Temperature Ceramic Plate Fin Heat Exchanger, Vijaisri Nagarajan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Compact heat exchangers are widely used in industries due to their compactness, reduced space, energy requirement and desired thermal performance. The proposed ceramic plate fin heat exchanger (PFHE) based on the offset strip fin design is used in applications which require extreme operating temperatures. It is well known that the compact heat exchanger requires small fins and channels to achieve high heat transfer rate and thermal performances. The fins in the ceramic heat exchanger ensure periodic restart of the boundary layer region which increases the thermal performance or heat transfer enhancement of the heat exchanger.

In this dissertation a novel …

What's Age Got To Do With It? Examining How The Age Of Stimulus Faces Affects Children's Implicit Racial Bias, Erica Cheree Noles

UNLV Theses, Dissertations, Professional Papers, and Capstones

Discrepant results regarding the emergence of children's implicit racial bias suggest additional research is needed to understand the developmental timeline of racial bias. Investigations using established explicit racial bias measures and the implicit association task with children demonstrate racial bias in young children (Aboud, 1988; Baron & Banjai, 2006). These findings do not corroborate the only known developmental use of the affective priming task (APT) to measure racial bias, which suggests implicit racial bias does not emerge until adolescence (Degner & Wentura, 2010). Variations in the task demands, the types of stimuli used to represent the construct of race, and …

Finite Difference Modeling Of Surface-~Wave Scattering For Shallow Cavity Detection, Heston Travis Norcott

UNLV Theses, Dissertations, Professional Papers, and Capstones

Data collection and analysis of scattering of Rayleigh-type surface waves are investigated for locating shallowly buried cavities. Surface-based seismic experiments conducted by others at the University of Nevada, Las Vegas (UNLV) Engineering Geophysics Test Site (EGTS) demonstrate scattering of Rayleigh waves caused by buried empty barrels (essentially air-filled cavities). The interpretation of the data is complicated by factors such as the presence of a high-velocity geologic layer just below the cavity.

This research uses a finite-difference seismic wave propagation code to compute time histories for a model that represents the Engineering Geophysics Test Site. By adding cavities to a background …

Sex In The Brain: The Relationship Between Event Related Potentials And Subjective Sexual Arousal, Taylor Lynn Oliver

UNLV Theses, Dissertations, Professional Papers, and Capstones

Research investigating the relationship between subjective sexual arousal and physiological arousal has focused primarily on measures of genital arousal and has yielded only modest concordance rates between genital and subjective sexual arousal in men, and low concordance rates in women. One of the nagging confounds in the literature, however, has been the fact that different assessment methods are necessitated by men and women's differing genital physiology (i.e., vaginal photoplethysmography in women and penile plethysmography in men). This study sought to investigate the relationship between subjective sexual arousal and a different type of physical arousal (brain activation) that could be measured …

Before You Knew Me, Isabel Ontiveros

UNLV Theses, Dissertations, Professional Papers, and Capstones

My thesis is a collection of short stories titledBefore You Knew Me. The collection centers on people whose lives have been affected by addiction or loneliness. Families attempt to get through adversities and piece together the fragments of a life they once had. Happiness for both the adults and the children depends on their ability to resist the cycle of dysfunction and the pressures of their peers.

The collection begins with a Gothic story about an abduction. My story "Goldfish" was inspired by Joyce Carol Oates's "Where Are You Going, Where Have You Been," where a young girl meets a …

Wisc-Iv Profiles In Children With Attention Deficit Hyperactivity Disorder And Comorbid Learning Disabilities, Elyse Parke

UNLV Theses, Dissertations, Professional Papers, and Capstones

Attention Deficit Hyperactivity Disorder (ADHD) and learning disabilities (LD), including Reading Disorder (RD), Disorder of Written Expression (DWE), and Developmental Coordination Disorder (DCD) all co-occur at high rates. Previous research indicates increased neurocognitive impairment in ADHD with the presence of comorbid diagnoses. However, few direct comparisons between intellectual profiles of children with one or multiple ADHD and LD diagnoses are available, specifically for the Wechsler Intelligence Scale Fourth Edition (WISC-IV), despite its frequent and historical use with this population. Profile analysis may contribute insights into spared and impaired abilities. Therefore, the present study addressed these matters by comparing WISC-IV profiles …

Takes Dying Animals, Brittany Leigh Bronson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The following collection represents three years of creative work in the Masters of Fine Arts-Fiction program at the University of Nevada Las Vegas. The majority of these stories operate in the realm of the surreal with comic and farcical leanings. All of the characters portrayed deal with death in some way--whether it a parent, a marriage, an animal, or a friend--and each cope their loss by pushing grief to the periphery, often masking it with humor or denial, until the story requires them to consciously confront it. These stories should not be considered finished work, but as a summation of …

Work And Home-Life Balance: A Comparative Study Of Hotel Employee Satisfaction In The West And Midwest, Amanda Connick

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study was conducted in the Western and Midwestern United States at mid-scale hotels with no food and beverage services regarding hotel employee satisfaction of work and home-life balance. The purpose of this study was to investigate the factors influencing employee perceptions of work and home-life balance, and to determine whether the regional locations of the work influence those perceptions.

The data was collected using an online survey from several hotels in the Western U.S. and Midwestern U.S. A total of 120 surveys were completed, 78 were usable. There were 45 respondents from the Midwest and 33 respondents from the …

Evaluation Of Conservation Voltage Reduction As A Tool For Demand Side Management, Ali Dorrody

UNLV Theses, Dissertations, Professional Papers, and Capstones

To ensure stability of the power grid, electricity supply and demand must remain in balance in real time. Traditionally utilities, call upon peaking power plants to increase power generation to meet the peak demand during the afternoons of the hot summer months. Demand-side management (DSM), which includes energy efficiency and demand response (DR), works from the other side of the equation - instead of adding more generation to the system, it pays energy users to reduce consumption as it is cheaper and easier to procure than traditional generation. As a consequence, demand-side management allows utility customers to act as a …

Evaluating The Impact Of A Home-~Based Childhood Asthma Intervention Program In Clark County, Nevada, Mackenzie Suzanne Burns

UNLV Theses, Dissertations, Professional Papers, and Capstones

Asthma is a chronic, incurable, costly, and potentially life–threatening disease that affects an estimated 7 million children in the United States; further, more than 56,000 Nevada children are currently living with asthma. The literature suggests that a number of factors that contribute to either the development of asthma or the exacerbation of asthma symptoms in sensitive individuals can be traced to the home environment. Given that the majority of Americans spend over 90% of their time indoors, of which two–thirds are spent at home, a home–based childhood asthma intervention program represents a unique primary prevention opportunity. This pre–experimental study evaluated …

Use Of Standardized Tests Within Nursing Education Programs, Irene Coons

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study explored the use of standardized tests within nursing programs. Standardized tests have been used within nursing programs for several decades (Shultz, 2010), but recently their use has increased. This rise in utilization may be related to the need for nursing programs to satisfy various accreditation requirements, including annual state board of nursing pass rates. However, standardized tests are not without controversy. For example, some believe that the tests can be detrimental to minority nursing students (Spurlock, 2006). Therefore, the purpose of the study was to assess how and why standardized tests are utilized within nursing programs.

Literature was …

The Effect Of Single Crystal Elastic And Plastic Anisotropy On Stress And Strain Heterogeneity: Comparison Of Olivine To Other Common Minerals, Christopher Joseph Cline Ii

UNLV Theses, Dissertations, Professional Papers, and Capstones

In order to investigate the influence of single crystal elastic anisotropy on the heterogeneity of stress distributions during polycrystalline deformation multiple deformed crystalline materials were analyzed using electron backscatter diffraction (EBSD). Deformation experiments were conducted on samples of Solnhofen limestone using a modified Griggs piston cylinder apparatus at UNLV, and also on San Carlos olivine using the D-DIA multi-anvil press at the National Synchrotron Light Source beamline X17B2. Analysis of the mechanical twins in deformed calcite and kink bands in olivine help elucidate deviations in local stress directions away from that of the applied macroscopic stress. Combined calculated compression directions …

Factors Which Predict The Use Of Active Transportation To School Among Children In Clark County, Nv, Sheila G. J. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Active transportation to school (ATS) shows promise for increasing activity levels in children, but prevalence and correlates vary widely in cities and regions with different barriers and supports for active travel. Classification of ATS users is a current issue in the field. The purpose of this study was to determine the prevalence of ATS use and develop a predictive model of ATS for the novel population of children enrolled in grades K-8 in Clark County School District, a large metropolitan school district in Southern Nevada. Methods: This study used a secondary data from the National Center for Safe Routes …

Investigating The Physical Properties And Runoff Treatment Capability Of Pervious Concrete Containing Granular Activated Carbon, Mark Elias Elkouz

UNLV Theses, Dissertations, Professional Papers, and Capstones

A current environmental concern is that of urban stormwater runoff, which can carry a multitude of contaminants and could threaten or impair surface waters. Pervious concrete (PC) is a type of concrete with significant void spaces that can facilitate infiltration and lead to less runoff. The EPA cites previous research to show that pervious pavement structures reduce such contaminants as metals and total suspended solids. Since Granular Activated Carbon (GAC) is a well-known contaminant adsorbent, the purpose of this research was to determine if PC with added GAC would result in improved runoff treatment, while still maintaining its material properties. …

Physics Of Gamma-Ray Bursts And Multi-Messenger Signals From Double Neutron Star Mergers, He Gao

UNLV Theses, Dissertations, Professional Papers, and Capstones

My dissertation includes two parts:

Physics of Gamma-Ray Bursts (GRBs): Gamma-ray bursts are multi-wavelength transients, with both prompt gamma-ray emission and late time afterglow emission observed by telescopes in different wavelengths. I have carried out three investigations to understand GRB prompt emission and afterglow. Chapter 2 develops a new method, namely, "Stepwise Filter Correlation" method, to decompose the variability components in a light curve. After proving its reliability through simulations, we apply this method to 266 bright GRBs and find that the majority of the bursts have clear evidence of superposition of fast and slow variability components. Chapter 3 gives …

The Effects Of A Single Bout Of Self-~Myofascial Release On Flexibility And Maximum Voluntary Contraction, Jonathan Robert Garcia

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The purpose of this study was to determine the effect of foam rolling on hamstrings flexibility, isometric and isokinetic torque. Participants: Thirteen female participants (N = 13; age: 28.5 + 6.8 years of age; height: 165.5 + 6.7 cm; mass: 64.2 + 8.4 kg) volunteered to participate in the study.

Methods: Hamstring flexibility was assessed using a sit and reach test; muscle strength was assessed by having participants complete a maximal voluntary isometric contraction (MVIC) of the hamstrings and maximal effort isokinetic knee flexion test using an isokinetic dynamometer. Participants completed these tests prior to any intervention (pre-rolling 1), …

The Application Of Zircon (U-Th)/He Thermochronology To Determine The Timing And Slip Rate On The Willard Thrust, Sevier Fold And Thrust Belt, Northern Utah, Bryan Eleogram

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although the Sevier fold-thrust belt is one of the best-studied foreland systems in the world, timing of motion on the dominant western thrust sheets that carry thick Neoproterozoic to Paleozoic strata remains incompletely understood. Zircon (U-Th)/He thermochrometry (ZHe) studies of the hanging wall of the Willard thrust sheet (WTS) in northern Utah are used to constrain the timing and rate of thrust slip. Previous interpretations of the age of initial slip on the Willard thrust vary widely from 150 to 115 Ma, reflecting ambiguous relations with foreland basin strata and limited geochronologic data. The large displacement on the Willard thrust …

Design And Analysis Of Hydrogen Powered Actuator Integrating Metal Hydride Storage System, Md Mainul Hossain Bhuiya

UNLV Theses, Dissertations, Professional Papers, and Capstones

The multi-fold purposes of this dissertation consists of construction, simulation and validation of a model describing hydrogen sorption kinetics in metal hydride. The project involves a comprehensive review of engineering applications involving metal hydrides and furthermore, design and investigation of a thermo-kinetically driven actuation system integrating metal hydrides for compact and soft robotic actuation. This will also shed some light on the feasibility of designing a damping system integrating metal hydride. Firstly, a mathematical model along with comprehensive simulation strategy of hydrogen absorption and desorption processes in porous metal hydride compacts was developed. A two dimensional axisymmetric model was built …

The Relationship Among School Playground Design And Conditions And Physical Activity Levels In Children, Ipuna Estavillo Black

UNLV Theses, Dissertations, Professional Papers, and Capstones

Almost 20% of children aged 6 to 11 years are obese in the United States, tripling over the last ten years. The rise in childhood obesity challenges nurses in their efforts to improve community health and sustainability. A decrease in physical activity (PA) levels has been associated with an increase in obesity. Schools have been identified as a primary setting to provide children adequate amounts of daily PA, and nurses working in the area of child health promotion can work with schools to provide opportunities for children to increase PA levels. The playground is one environment where children can increase …

Smart Data Collection Using Mobile Devices To Improve Transportation Systems, Tharindu Dasun Abeygunawardana

UNLV Theses, Dissertations, Professional Papers, and Capstones

Travel time is a matter that affects most of us, especially those that live in highly congested cities. Ideally, we want to reduce travel time as much as possible, thereby freeing up more of our time and enabling a higher quality of life. Data collection of transportation metrics helps us get a clearer picture of the transportation system, and helps us make smarter choices when it comes to improving the existing system. The rapid emergence of interconnected mobile devices carried along by travelers opens up many possibilities for gathering data as they travel, and also to serve them relevant data …

Behind His Father's Saying: Robert Frost's Wisdom Tradition, James H. Altman

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is no coincidence that Robert Frost draws on the European/American aphoristic wisdom tradition. From the fables of Aesop, to the esotericism of pre-Socratic Greek philosophers such as Pythagoras and Empedocles, to the works of moralists like Blaise Pascal and Michel De Montaigne, to Erasmus, Frederick Nietzsche and others, Robert Frost weaves diverse wisdom into his work. He does not, however, as much take verbatim the words or sentiments of those who inspire him. Rather he adapts the spirit of their thoughts for his own purposes. Why and how does he do this? What are those purposes, and their subsequent …