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A One-Dimensional Analysis Of A Microbial Fuel Cell For Efficient Acetate Removal And Power Density Output, David Rouhani
A One-Dimensional Analysis Of A Microbial Fuel Cell For Efficient Acetate Removal And Power Density Output, David Rouhani
UNLV Theses, Dissertations, Professional Papers, and Capstones
Microbial fuel cells (MFCs) are electrochemical devices that utilize microorganisms to convert organic matter into electrical energy. MFCs have been discussed to have potential application for sustainable wastewater treatment due to their ability to generate electricity while simultaneously treating contaminated water. To optimize MFC performance, numerical models can be used to understand the complex electrochemical and biological processes occurring in the system. In this study, a numerical model was developed to simulate the performance of MFCs under varying operating conditions and to investigate the performance of a MFC for treating wastewater fuel. More specifically, the MFC was modeled to oxidize …
Discrete Vortex Modeling Of Aerodynamic Flutter Of A Flat Plate With Damped Oscillations, Emma Chao
Discrete Vortex Modeling Of Aerodynamic Flutter Of A Flat Plate With Damped Oscillations, Emma Chao
UNLV Theses, Dissertations, Professional Papers, and Capstones
Aerodynamic flutter is the unstable oscillation of a body caused by the interaction of aerodynamic forces, structural elasticity, and inertial effects induced by vortex shedding. Current models of this phenomenon require finite element analysis and extensive computational power and processing time. The purpose of this study was to develop and validate a program that is faster and more efficient than existing approaches by using the discrete vortex method (DVM). By reducing the complexities of flutter to the shedding of vortices in an inviscid model of a two-dimensional flat plate with a torsional spring constant at its center, this phenomenon can …
Hydroclimatic Forecasting In The Western United States Using Paleoclimate Reconstructions And Data-Driven Models, Christopher Allen Carrier
Hydroclimatic Forecasting In The Western United States Using Paleoclimate Reconstructions And Data-Driven Models, Christopher Allen Carrier
UNLV Theses, Dissertations, Professional Papers, and Capstones
This thesis investigated climate variability and their associated hydrologic responses in the western United States. The western United States faces the problem of water scarcity, where the management and mitigation of available water supplies are further complicated by climate variability. Climate variability associated with the phases of oceanic-atmospheric oscillations has been shown to influence streamflow and precipitation, where predictive relationships have led to the possibility of producing long-range forecasts. Based on literature review, four oceanic-atmospheric oscillation indices were identified in having the most prominent influence over the western United States including the El Niño - Southern Oscillation (ENSO), Pacific Decadal …
Empirical Testing Of The Neuman Systems Nursing Education Model: Exploring The Created Environment Of Registered Nursing Students In Nevada’S Colleges And Universities, Diane H. Elmore
UNLV Theses, Dissertations, Professional Papers, and Capstones
The purposes of this paper are to: (a) present the strategies and rationale for creation of a middle range nursing theory that is specific to nursing education, (b) to determine if propositions of the model are valid and appropriate to support further research based on the student-centered education model, and (c) to conduct initial research on the created environment of nursing students, which is one of two the primary constructs of the nursing education model. Use of the Neumans Systems Nursing Education Model (NSNEM), a student centered educational model, which is consistent with the Neumans System Model (NSM) provided the …
A Mathematical Model For Computerized Car Crash Detection Using Computer Vision Techniques, Dawn Marie Strianese
A Mathematical Model For Computerized Car Crash Detection Using Computer Vision Techniques, Dawn Marie Strianese
UNLV Retrospective Theses & Dissertations
My proposed approach to the automatic detection of traffic accidents in a signalized intersection is presented here. In this method, a digital camera is strategically placed to view the entire intersection. The images are captured, processed and analyzed for the presence of vehicles and pedestrians in the proposed detection zones. Those images are further processed to detect if an accident has occurred; The mathematical model presented is a Poisson distribution that predicts the number of accidents in an intersection per week, which can be used as approximations for modeling the crash process. We believe that the crash process can be …
Standardization Of References Using Hidden Markov Model, Swamynathan Sambamurthy
Standardization Of References Using Hidden Markov Model, Swamynathan Sambamurthy
UNLV Retrospective Theses & Dissertations
In general, technical papers are augmented with a list of bibliographic citations to support the arguments and the merits of the approach presented. Each and every citation is made up of parts like author, journal, volume, book etc. Extracting the parts of the citation from a written document and properly separating into its parts is the problem that is being addressed in this thesis; We use an Information Extraction (IE) technique based on Hidden Markov Model (HMM) to solve this problem. This solution consists of the design of an HMM, the training of the HMM with tagged data, and an …
A Cfd Model To Predict Pressure Loss Coefficient In Circular Ducts With A Motorized Damper, Pallavi Annabattula
A Cfd Model To Predict Pressure Loss Coefficient In Circular Ducts With A Motorized Damper, Pallavi Annabattula
UNLV Retrospective Theses & Dissertations
The pressure loss coefficient was determined for a circular duct with a circular damper using computational fluid dynamics. The CFD package Star-CD was used to predict the air flow and pressure distribution in the duct. A three dimensional computational fluid dynamics model was developed and simulated for five different positions of the damper ranging from partially opened position to completely opened position. The available standard k-epsilon model for high Reynolds number was used. The duct was also simulated for different flow conditions by varying the Reynolds number. The code generated the pressure drop across the damper, which was used to …
Mathematical Model To Simulate A Hybrid Lighting System, Ahmad Abu Heiba
Mathematical Model To Simulate A Hybrid Lighting System, Ahmad Abu Heiba
UNLV Retrospective Theses & Dissertations
Hybrid solar lighting (HSL) technology is a relatively new technology to utilize natural sunlight along with the traditional electric lighting to light the interior spaces. HSL systems concentrate the sunlight onto a bundle of optical fibers. The optical fibers are routed into the interior space and coupled with cylindrical rods to diffuse the light. A lighting sensor modulates the amount of electric energy depending on the amount of natural light available; This study presents a simplified mathematical model to predict the output of the HSL system based on the amount of the available solar radiation. The model is verified via …
Prehistoric Settlement And Land Use: A Predictive Model Of The Shivwits Plateau, Northwest Arizona, Glendee Ane Osborne
Prehistoric Settlement And Land Use: A Predictive Model Of The Shivwits Plateau, Northwest Arizona, Glendee Ane Osborne
UNLV Retrospective Theses & Dissertations
The objective of this research is to develop, test, and utilize a Geographic Information Systems based predictive model of prehistoric site location and settlement for the Shivwits Plateau in northwestern Arizona to better understand settlement patterns and land use across the region from the Archaic to Protohistoric period. The GIS data are used to determine site location probability for specific temporal phases of Virgin Anasazi cultural activity. The database includes previously recorded sites, vegetation, elevation, aspect, slope, and water resources which are integrated to establish probable patterns of land use and settlement; My thesis examines two research questions. First, is …
Lodging Capacity Optimization: Application Of An Inventory Model To China's Lodging Industry, Tianshu Zheng
Lodging Capacity Optimization: Application Of An Inventory Model To China's Lodging Industry, Tianshu Zheng
UNLV Retrospective Theses & Dissertations
Since China decided to promote tourism in 1978, the rapidly increasing number of foreign visitors has continuously put pressure on China's tourism infrastructure and service facilities. To keep up with the demand, China's hotel industry has been expanding at a growth rate that is faster than that of foreign visitors. In 1990s, the overdevelopment became a problem confronting the China's hotel industry. However, the hotel supply has continuously been increasing beyond the demand. Severe over-capacity is likely to occur in China's hotel industry time series analysis and single-period inventory model, this dissertation estimates the optimal capacity for both China's and …
A Systematic Approach To An Integrated Curriculum Model For Dental Education, Tanis Maria Stewart
A Systematic Approach To An Integrated Curriculum Model For Dental Education, Tanis Maria Stewart
UNLV Retrospective Theses & Dissertations
The purpose of this quantitative study was to determine the degree of curriculum integration within dental schools in North America. The intent of the study was to determine how an adaptation of the Fogarty (1991) framework of integration exhibits itself in dental education; An electronic survey conducted of the Academic Deans of dental schools in the United States and Canada resulted in a response rate of 54.09% (33/61). Frequencies, chi-square and Spearman rho (p) correlation coefficient were used for the statistical analyses of data; All survey respondents reported that their curricula include all levels of integration which comprise the adapted …
The Development Of A Replicable Model For Implementation Of A High School Minimum Competency Program, Nils Golden Bayles
The Development Of A Replicable Model For Implementation Of A High School Minimum Competency Program, Nils Golden Bayles
UNLV Retrospective Theses & Dissertations
Problem. A twenty year decline on college entrance examination test scores achieved by high school students and two massive national studies of education in the United States, the Coleman Report and the National Assessment of Educational Progress, highlighted a nationwide concern about student.
The Development Of A Consensus Management By Objectives Model And A Comparison To The Clark County School District Management And Accountability System For Secondary Schools, Agustin A Orci
UNLV Retrospective Theses & Dissertations
The purpose of the study was to examine selected business and education management by objectives (MBO) models and identify the common elements. These elements resulted in a consensus MBO model which was compared to determine agreement with the Clark County School District's Management and Accountability System for Secondary Schools. Educational accountability, the theoretical bases for MBO and MBO models in business and education were treated in the review of the literature. Graphic models developed in the study included the Clark County District's Management and Accountability System for Secondary Schools and a consensus MBO model; A management process based on the …
Model Of Early Universe With H+2, Tae Song Lee
Model Of Early Universe With H+2, Tae Song Lee
UNLV Retrospective Theses & Dissertations
The aim of this thesis is to improve existing models of the Early Universe by adding vibrationally resolved reactions to a standard model. Stancil, Lepp, and Dalgarno (1996, 1998) have developed a standard chemical model for molecules in the Early Universe. Galli and Palla (1998) have shown that vibrational excitation may be important in this model by forcing the vibrational level of H+2 to be either v=0 or v=9. I studied a consistent model for the vibrational levels including level dependent formation and destruction as well as transition between the levels.
Atmospheric Dispersion Model Validation For Low Wind Speed Conditions, Patrick Shawn Sawyer
Atmospheric Dispersion Model Validation For Low Wind Speed Conditions, Patrick Shawn Sawyer
UNLV Retrospective Theses & Dissertations
Atmospheric plume dispersion models are used for a variety of purposes including emergency planning and response to hazardous material releases, determining force protection actions in the event of a WMD attack and for locating sources of pollution. This paper provides a review of previous studies that examine the accuracy of atmospheric plume dispersion models for chemical releases. It considers the principles used to derive air dispersion plume models and looks at three specific models currently in use; ALOHA, EPIcode and SCIPUFF. Results from this study indicate over-prediction bias by the EPIcode and SCIPUFF models and under-prediction bias by the ALOHA …
Extending The Delone And Mclean Information Systems Success Model For E-Commerce Website Success, Joy Wendy Wu
Extending The Delone And Mclean Information Systems Success Model For E-Commerce Website Success, Joy Wendy Wu
UNLV Retrospective Theses & Dissertations
Website evaluation can continuously improve the performance of websites and increase sales. However, the lack of a comprehensive framework as guidance hampered this task. The main purpose of this research is to provide a comprehensive framework for e-commerce websites evaluation by extending the DeLone and McLean Information System Success Model. A new dimension---"Relationship quality" is proposed to the model. The study also tries to identify characteristics of e-commerce websites that impact the user's satisfaction; A survey questionnaire was distributed to web users, and a total of 295 responses were obtained. The data was processed through Statistical Package for the Social …
Estimating The Effects Of Casino Marketing Activities On Slot Business Volume: A Model For Leisure Services Businesses, Lisa Birtciel Young
Estimating The Effects Of Casino Marketing Activities On Slot Business Volume: A Model For Leisure Services Businesses, Lisa Birtciel Young
UNLV Retrospective Theses & Dissertations
This study researched the effect of marketing promotions on gaming volume (i.e., coin-in). Specifically, this study attempted (1) to gain an understanding of the relationship between specific marketing promotions (slot tournaments, special events, product prize drawings, and no marketing promotions) and gaming volume; and (2) to estimate the magnitude of incremental revenue for each type of promotion. A conceptual model was proposed to examine the effect of the different types of marketing promotions on gaming volume, including two other variables (holidays and day-of-the-week) previously found to influence gaming volume; Secondary data were collected from a Las Vegas Strip property for …
A General Mathematical Model Of Stenoses, Jordan Jimmy Crabbe
A General Mathematical Model Of Stenoses, Jordan Jimmy Crabbe
UNLV Retrospective Theses & Dissertations
Incidence and the prevalence rate of stroke in the United States has been of great concern to the Centers for Disease Control and prevention (CDC), National Center for Health Statistics (NCHS), the American Society of Stroke, American Stroke Association and the U.S. government as a whole; Many mathematical models of the stroke problem have been proposed and solved using diverse methods and computations. Most of the models are based on the stenoses, occlusion or rupture of the artery and the formation of cerebral aneurysms, which all lead to the occurrence of stroke; This paper utilizes a direct approach to change …
A Model For Programming Characteristics Of Sonos Type Flash With High-Kappa Dielectrics, Varun Jain
A Model For Programming Characteristics Of Sonos Type Flash With High-Kappa Dielectrics, Varun Jain
UNLV Retrospective Theses & Dissertations
Silicon Oxide Nitride Oxide Silicon (SONOS) FLASH memories have recently gained a lot of attention due to better retention and scaling opportunities over the conventional Floating Gate FLASH memories. The constant demand for device scaling, to attain higher density, higher performance, and low cost per bit, has posed charge leakage problems. SONOS type devices with high-kappa storage layers and/or high-kappa blocking oxide have been proposed to alleviate the demand for constant tunnel oxide scaling. In comparison to conventional FLASH, these devices operate at lower voltages, exhibit higher programming speeds, comparable retention times, less over-erase problem and better compatibility with low …
Diffusion Model For Lightning Radiative Transfer Using Spherical Geometry, James Beguah Odei
Diffusion Model For Lightning Radiative Transfer Using Spherical Geometry, James Beguah Odei
UNLV Retrospective Theses & Dissertations
A one-speed Boltzmann transport theory, with diffusion approximations, is applied to study the radiative transfer properties of lightning in optically thick thunder clouds. The cloud is modeled in terms of spherical geometry and studies on the effects of multiple scattering are considered. Mathematically, the cloud is composed of a homogeneous distribution of spherical water droplets. Computationally, the cloud is treated as a nuclear reactor, with photons replaced by neutrons. Diffusion techniques common in nuclear reactor analyses are applied as in [1]. Relevant numerical techniques will be used to simulate the Cloud Results for the obtained intensity distribution will be compared …
Development Of A Flood Forecasting Model For Flamingo Tropicana Watershed In The Las Vegas Valley, Satya Prakash Chataut
Development Of A Flood Forecasting Model For Flamingo Tropicana Watershed In The Las Vegas Valley, Satya Prakash Chataut
UNLV Retrospective Theses & Dissertations
Floods are among the most frequent natural phenomenon that occur due to excessive precipitation. Accurate and current forecasting of floods is necessary to avoid social and economic losses. Forecasting floods in an event of intense rain allows the concerned agencies to adopt appropriate measures such as warnings and evacuations and to initiate corrective and remedial efforts before disaster strikes (Chapman and Canaan, 2001); Las Vegas has experienced rapid population growth since the 1990s. This has brought large-scale increase in impervious land surface due to the expansion of residential, commercial, and industrial area in the valley. The increase in impervious area …
A Diffusion Model Of Lightning Radiative Transfer Using Cylindrical Geometry, Rina Alfonso Santos
A Diffusion Model Of Lightning Radiative Transfer Using Cylindrical Geometry, Rina Alfonso Santos
UNLV Retrospective Theses & Dissertations
Clouds come in different shapes and sizes and are made up of different constituents. Realistic clouds are composed of heterogeneous distribution of constituents (ice particle, needle shaped objects, cubic, hexagonal, etc.). For tractability of solutions and smoothness of calculations, assumptions are made. The assumption is viable due to multiple scattering effect for propagation of radiation in random media. In Koshak et al. (1994), "Diffusion Model for Lightning Radiative Transfer", the cloud was treated as a nuclear reactor in order to obtain forms that can be readily computable and a simple geometry was chosen, i.e., a homogeneous rectangular parallelepiped Cloud In …
Creating And Testing The Higher Education Leadership Competencies (Helc) Model: A Study Of Athletics Directors, Senior Student Affairs Officers, And Chief Academic Officers, Zachary A Smith
UNLV Retrospective Theses & Dissertations
The purpose of this study was threefold: to extend existing knowledge of McDaniel's (2002) qualitative inquiry of higher education leadership competencies by testing her theory using quantitative methods; to either affirm or create a new, more refined model of higher education leadership competencies based on the results of the data analysis; and finally, to compare the similarities and differences of important competencies necessary for effective leadership between and within three groups of leaders in higher education: athletics directors (ADs), senior student affairs officers (SSAOs), and chief academic officers (CAOs); Goodness of fit results indicated McDaniel's 4-category model of higher education …
Examining Women Faculty Experiences Using The Model Of Human Occupation Perspective: A Qualitative Approach In One Community College, Christine R Privott
Examining Women Faculty Experiences Using The Model Of Human Occupation Perspective: A Qualitative Approach In One Community College, Christine R Privott
UNLV Retrospective Theses & Dissertations
Occupations for women in the academy have been changing over the last century. Contemporary studies that have looked at women faculty work have been mixed in their findings about the relationship between gender and job satisfaction. Few studies have focused on two-year-college models of women's experiences as faculty; Set in the context of occupational science theories, this qualitative study explored the daily work of women faculty in one community college. The concept of faculty work was viewed through Kielhofner's Model of Human Occupation, which suggests that occupations are made up of three subsystems of human action or doing: volition, habituation, …
A Model Of The Interplay Of Culture And Immigration Stress In The Development And Maintenance Of Alcohol-Related Disorders In Hispanic/Latino Immigrants, Marilyn J Strada
A Model Of The Interplay Of Culture And Immigration Stress In The Development And Maintenance Of Alcohol-Related Disorders In Hispanic/Latino Immigrants, Marilyn J Strada
UNLV Retrospective Theses & Dissertations
The Hispanic/Latino population represents the largest ethnic minority group in the United States, with immigrants comprising a substantial portion of this population. For both U.S.-born and immigrant Hispanic/Latinos, alcohol abuse and dependence is of particular concern given their reported high prevalence rates, the severe alcohol-related consequences that they experience, and the various barriers to obtain treatment that they encounter. In comparison to members of other ethnic groups, Hispanics/Latinos have the lowest rates of perceived need for treatment, the lowest past and current rates of participation in treatment and the highest dropout rates after attending just one counseling session. Although there …
Uncertainty Analysis: Mid-Term Operational Model For The Lower Colorado River, Shana Goffman Tighi
Uncertainty Analysis: Mid-Term Operational Model For The Lower Colorado River, Shana Goffman Tighi
UNLV Retrospective Theses & Dissertations
Water managers at the U.S. Department of Interior, Bureau of Reclamation as well as other federal and local agencies use a monthly modeling tool called the 24-Month Study as the numerical basis of many decisions along the Lower Colorado River. It is a deterministic model and currently does not provide information about the uncertainty associated with forecasted outputs. As water resource management becomes increasingly based on technical models, managers realize the importance of the ability to understand and quantify uncertainty. This thesis contributes to efforts in this arena by accomplishing the following objectives: (1) identification of the various sources of …
Development Of An Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Matthew S Hodges
Development Of An Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Matthew S Hodges
UNLV Retrospective Theses & Dissertations
Major issues concerning nuclear waste storage at Yucca Mountain are that of safety and long term disposal. Approximately one percent of the content of spent nuclear fuel is that which is responsible for nearly all the long-term associated health risks. The removal and transmutation of this content will render the toxicity of the remaining waste to that of natural uranium within a few hundred years. The research contained in this thesis details several simulations that are involved in the overall removal process. The first objective was to test the feasibility of the design of a distillation column that will separate …
An Arima-Model-Based Approach With Hazard Area For The Probability Of Volcanic Disruption Of The Proposed High-Level Radioactive Waste Repositiory At Yucca Mountain, Nevada, Usa, Xiaojuan Liu
UNLV Retrospective Theses & Dissertations
An interesting extension of advanced time-series analysis techniques is introduced into the domain of volcanological data exploration. A new and innovative use of the well-known ARIMA method for modeling the recurrence rate of volcanism ranging from simple Poissonian volcanoes to those showing cyclic trends is presented. Specifically, we propose a new tool to fingerprint the eruptive behavior of a volcano, which also links some modeling tools of two of the most developed areas in the literature of statistics: stochastic processes and time series. Valuable modeling and computing insights are discussed using a data set from the volcanic database at Yucca …
Gambling Behavior And The Five Factor Model Of Personality, Edward W Crossman
Gambling Behavior And The Five Factor Model Of Personality, Edward W Crossman
UNLV Retrospective Theses & Dissertations
Recent research has correlated gambling with age, gender, ethnicity and various specific personality traits. No previous research has examined the predictive value that the Five-factor model of personality may lend to level of gambling. The Five-factor model argues that variation in human personality can be largely captured along five dimensions: Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness (Costa & McCrae, 1992). The current study examined the relationship between level of gambling and the Five-factor model of personality in a sample of college students. Regression analysis was used to determine if any of the dimensions of the Five-factor model predict …
A Comprehensive Structural Model Of Factors Affecting Online Consumer Travel Purchasing, Hsing Wen
A Comprehensive Structural Model Of Factors Affecting Online Consumer Travel Purchasing, Hsing Wen
UNLV Retrospective Theses & Dissertations
The purpose of this research was to develop a comprehensive model to study consumers' online purchase intention of travel products. Related literature reviews suggested antecedents of consumers' online purchase intention including EC travel web site design, past purchase experience, consumer trust, consumer's attitudes toward online shopping of travel products; The model was developed by integrating one existing theoretical model (Shim's Online Pre-purchase Intentions Model) with several important factors which were guided by theories: (1) social cognitive theory, (2) self-efficacy theory, (3) theory of planned behavior (TPB), (4) attitude-behavior consistency theory, (5) theory of consumer trust, and (6) communication theory. As …