Digital Commons Network^™

Understanding Progenitors Of Gamma Ray Bursts With Multi-Wavelength Properties, Ye Li

UNLV Theses, Dissertations, Professional Papers, and Capstones

Gamma-ray bursts (GRBs) are among the most brilliant explosions in the universe, named for their intense, seconds-duration $\gamma$-ray emission. They are generally classified into two categories according to the durations of their $\gamma$-ray emission: the long-duration GRBs (LGRBs) with durations more than 2 seconds, and the short-duration GRBs (SGRBs) with durations less than 2 seconds. Most SGRBs are believed to originate from mergers of compact stars (e.g., neutron star-neutron star and neutron star-black hole; also known as Type I GRBs by their physical mechanism), while the LGRBs are thought to originate from core-collapse of massive stars (Type II). In addition …

A Comparison Of Outdoor Bioaerosol And Particulate Measurements In Las Vegas, Tanviben Yogeshkumar Patel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The urbanization of the Las Vegas Valley has turned the desert into a green oasis by introducing many non-native plant species, some of which are allergenic. Outdoor bioaerosols consist of microorganisms, pollen, spores, and other agents that could cause infections or affect the health of humans. Studies have suggested that exposure to bioaerosols through inhalation can lead to various human health risks. Typically, one monitoring station is established per city to obtain pollen and mold counts for an entire metropolitan area, and the site may not be representative of community exposures. The objective of this study was to measure and …

Using Mobile Technology To Increase The Math Achievement And Engagement Of Students With Disabilities, Dominique Marie Tetzlaff

UNLV Theses, Dissertations, Professional Papers, and Capstones

The advent of advanced technologies provides new opportunities for delivering instruction to students with disabilities. Many classrooms have access to mobile devices, such as iPads and Kindles, and educators utilize these devices to differentiate instruction and augment teacher-led instruction. This delivery method, known as blended learning, can create an enriched learning environment where students are exposed to individualized lessons that are self-paced and provide multiple modes of presentation. However, there is little empirical investigation into how students interact with digital devices or what components of online learning directly impact student learning and engagement with the content. In order to design …

The Formation And Dynamics Of Clouds In The Environment Of Active Galactic Nuclei, Timothy Waters

UNLV Theses, Dissertations, Professional Papers, and Capstones

Active galactic nuclei (AGN) are among the most luminous objects in the universe and are known to be powered by accretion onto supermassive black holes in the centers of galaxies. AGN clouds are prominent components of successful models that attempt to unify the diversity of AGN. These clouds are often hypothesized to be the source of the broad and narrow line emission features seen in AGN spectra. Moreover, the high column densities of gas needed to account for broad absorption lines has been attributed to the same population of clouds, while the motion of AGN clouds has been invoked to …

Improved Partial Charge Models In Siliceous Zeolites For The Simulation Of Adsorption And Identification Of Catalytic Sites, Jarod J. Wolffis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Utilization of computational modelling and simulation is expanding as computer processing power has increased and as new tools have been developed. This thesis focuses on efforts to improve the accuracy of simulations in aluminosilicate zeolites, an industrially important category of materials for catalysis and separations. For these sorbents, partial atomic charge represents a critical parameter in molecular mechanics simulations, determining the Coulombic non-bonding interaction. Partial charges may also be used as a measure of important physical parameters of the system such as the degree of covalency or the relative acidity of catalytic sites. We compare several common methods for predicting …

Improving Pattern Recognition And Neural Network Algorithms With Applications To Solar Panel Energy Optimization, Ernesto Zamora Ramos

UNLV Theses, Dissertations, Professional Papers, and Capstones

Artificial Intelligence is a big part of automation and with today's technological advances, artificial intelligence has taken great strides towards positioning itself as the technology of the future to control, enhance and perfect automation. Computer vision includes pattern recognition and classification and machine learning. Computer vision is at the core of decision making and it is a vast and fruitful branch of artificial intelligence. In this work, we expose novel algorithms and techniques built upon existing technologies to improve pattern recognition and neural network training, initially motivated by a multidisciplinary effort to build a robot that helps maintain and optimize …

A Review Of Time Relaxation Methods, Sean Breckling, Monika Neda, Tahj Hill

Mathematical Sciences Faculty Research

The time relaxation model has proven to be effective in regularization of Navier–Stokes Equations. This article reviews several published works discussing the development and implementations of time relaxation and time relaxation models (TRMs), and how such techniques are used to improve the accuracy and stability of fluid flow problems with higher Reynolds numbers. Several analyses and computational settings of TRMs are surveyed, along with parameter sensitivity studies and hybrid implementations of time relaxation operators with different regularization techniques.

Social Determinants Of Health Associated With Hbv Testing And Access To Care Among Foreign-Born Persons Residing In The United States: 2009 - 2012, Kevin M. Greene, Wayne A. Duffus, Jian Xing, Hope King

Journal of Health Disparities Research and Practice

Objectives: To describe how select Social Determinants of Health (SDH) are associated with the burden of hepatitis B virus (HBV) infection among foreign-born persons residing in the United States.

Methods: Multivariate logistic regression was used to examine the Racial and Ethnic Approaches to Community Health (REACH) 2010 Risk Factor Survey data to investigate the independent relationship between SDH and HBV testing and access to care.

Results: HBV infected persons with insurance were more likely to see a physician than those without. Respondents worried about money to pay rent or mortgage were more likely to report HBV infection than …

Using Proxies For Node Immunization Identification On Large Graphs, Raymond Ahn, Justin Zhan

Computer Science Faculty Research

Given a large graph, like a social network, which nodes should be immunized (or removed) to make the network safe from the spread of a virus? This is the node immunization problem. One of the classical methods, inspired by immunology, in analyzing this problem relies on the calculation of the largest eigenvalue before and after immunization in order to create the largest difference in eigenvalue. We propose a method that does not rely on a costly calculation of eigenvalues; instead, we rely on the notion of proxies and deterministic routing areas in order to find such nodes to immunize. We …

Giving Matters: Donors Making A Difference, Unlv Foundation

Giving Matters

No abstract provided.

Sustainability Standards And Stakeholder Engagement: Lessons From Carbon Markets, Hans Rawhouser, Michael E. Cummings, Alfred Marcus

Management, Entrepreneurship and Technology Faculty Research

Stakeholders play an increasingly active role in private governance, including development of standards for measuring sustainability. Building on prior studies focused on standards and stakeholder engagement, we use an innovation management theoretical lens to compare stakeholder engagement and standards developed in two carbon markets: the Climate Action Reserve and the U.N.’s Clean Development Mechanism. We develop and test hypotheses regarding how different processes of stakeholder engagement in standard development affect the number, identity, and age of stakeholders involved, as well as the variation and quality of the resulting standards. In doing so, we contribute to the growing literature on stakeholder …

Higher Education Capacity Building In Water Resources Engineering And Management To Support Achieving The Sustainable Development Goal For Water In Pakistan, Steven J. Burian, Mercedes Ward, Tariq Banuri, M. Aslam Chaudhry, Sajjad Ahmad, Bakhshal Lashari, Rasool Bux Mahar, Davey Stevenson, Jim Vanderslice, Kamran Ansari, Munir Babar, Abdul Latif Qureshi

Civil and Environmental Engineering and Construction Faculty Research

Achieving the Sustainable Development Goals requires a multi‐pronged approach, with a key element being the development of a trained Community of Practice to sustain the advances in the relevant sectors. The engagement of higher education as a catalyst in the development and capacity building of the next generation of professionals and citizens comprising the Community of Practice is essential to meet the challenges of poverty, climate change, and clean water and to sustain those advances past 2030. This paper describes a capacity building program funded by the United States Agency for International Development to partner the University of Utah, in …

Elastic Waves In Fractured Rocks Under Periodic Compression, Aleksei Talonov, Elena Kossovich, Viktoria Savatorova

Mathematical Sciences Faculty Research

Background: One of the current problems in studying the mechanical properties and behavior of structurally inhomogeneous media with cracks is the characterization of acoustic wave propagation. This is especially important in Geomechanics and prognosis of earthquakes. Methods: In this work, the authors propose an approach that could simplify characterization of wave propagation in medium with cracks. It is based on homogenization procedure performed at a set of equations characterizing acoustic wave propagation in media weakened by fractures under condition of external distributed loading. Such kind of loading in most cases is close to the real one in case of consideration …

Potential Of Rainwater Harvesting In Meeting The Domestic Outdoor Demand: A Study In Dry And Wet Regions Of The United States, Kazi Ali Tamaddun, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Feasibility of meeting the outdoor water demand with rainwater harvesting (RWH) was evaluated for the states of Arizona and Florida as representatives of dry and wet regions, respectively, using a system dynamic model. The potential of RWH was found to be highly sensitive to the demand of water, desert landscaping potential, and the percentage of households with RWH systems. The percentage of demand met through RWH and the storage potential of a 50-gallon rainwater barrel was found to be significant even for arid regions. The model can be used to compare among various influencing parameters of RWH systems.

Study Of Potential Integrated Management Of Water Resources In Las Vegas Valley, Haroon Stephen, Yoohwan Kim, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Water resource management under short term system perturbations such as storms and longer-term systemic changes caused by climate change such as droughts is a challenge when multiple agencies are involved. To address this challenge this research focuses on water management under changing climate conditions and population growth through understanding the agency water jurisdictions, management strategies, and modes of operation in Las Vegas Valley. A framework for integrated management through sharing data and models is presented that combines drinking water supply, flood control, and waste water treatment. This framework can be adopted to improve coordination among different water management agencies.

2d Unsteady Routing And Flood Inundation Mapping For Lower Region Of Brazos River Watershed, Manahari Bhandari, Narayan Nyaupane, Shekhar Raj Mote, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Present study uses two dimensional flow routing capabilities of hydrologic engineering center's river analysis system (HEC-RAS) for flood inundation mapping in lower region of Brazo River watershed subjected to frequent flooding. For analysis, river reach length of 20 km located at Richmond, Texas, was considered. Detailed underlying terrain information available from digital elevation model of 1/9-arc second resolution was used to generate the two-dimensional (2D) flow area and flow geometrics. Streamflow data available from gauging station USGS08114000 was used for the full unsteady flow hydraulic modeling along the reach. Developed hydraulic model was then calibrated based on the manning's roughness …

Ice-Cover And Jamming Effects On Inline Structures And Upstream Water Levels, Addison Jobe, Swastik Bhandari, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

River ice cover is a reoccurring phenomenon in the Northern United States every year. Sheets and layers of ice result in a rise of water surface elevation and may lead to ice jams in a river. This research explains the modeling of a river reach through Northern Illinois containing a structural weir and how the water profile is effected during ice cover and ice jam events. The Hydraulic Engineering Center’s River Analysis System was used in conjunction with Esri ArcMap software to model a portion of the river for analysis. The study area of the Rock River flowing through Oregon, …

Multi-Scale Correlation Analyses Between California Streamflow And Enso/Pdo, Kazi Ali Tamaddun, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) are two of the most important climate indices that influence the western U.S. hydrology significantly. This study evaluated how these two indices have influenced California streamflow over the years and determined their correlation at multiple time-scales. Data were obtained from 14 unimpaired streamflow stations of California for a study period of 63 years (i.e., 1951 to 2013). The concept of continuous wavelet transform was applied to observe the variance in each time-series at multiple time-scale bands over the years. The correlation was found to be higher in the latter half …

Precipitation And Indian Ocean Climate Variability-Acase Study On Pakistan, Kazi Ali Tamaddun, Ajay Kalra, Waqas Ahmed, Ghulam Hussain Dars, Steve Burian, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

The study evaluated the relationship between two climate variability indicators – sea- surface temperature (SST) and 500-mbar geopotential height (HGT/Z500) – and the monsoonal precipitation pattern of Pakistan. Data from 30 precipitation gauges were obtained and were analyzed over a period of 35 years from 1980 to 2014. Singular-valued decomposition (SVD) technique was used to determine the association of previous year’s SST and HGT with the current year’s monsoonal precipitation. The results indicated that the association of SST and HGT with precipitation varied depending on the lead-times selected. Multiple regions of the North Indian Ocean were identified that showed significant …

Response Of Climate Change On Urban Watersheds: A Case Study For Las Vegas, Nv, Narayan Nyaupane, Ranjeet Thakali, Ajay Kalra, Lorenzo Mastino, Marco Velotta, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

The current research is a partnering effort between Southern Illinois University Carbondale and City of Las Vegas to assess the vulnerability to drought, extreme heat, and extreme precipitation. This study focuses on precipitation and usesdifferent climate scenarios from the high-resolution North American Regional Climate Change Assessment Program (NARCCAP) climate model data to evaluate the existing stormwater infrastructure of the Gowan watershed in the Las Vegas valley. Six NARCCAP modelsconsidered in the study have shown the Gamma distribution as the best fitted from Kolmogorov Smirnov best fit test. Delta change method is adopted to quantify the effect of climate change on …

Flood Risk Assessment Using The Updated Fema Floodplain Standard In The Ellicott City, Maryland, United States, Ranjeet Thakali, Ranjit Bhandari, Giles-Arnaud Arif-Deen Kandissounon, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Every Year, flooding causes a calamitous impact on the people, economy, and environment all over the world. In recent years, the flood-related damages have been increasing in the United States regardless of several investments in the flood control measures. Floodplain mapping is an important tool for management that aids in the planning of infrastructures within the floodplain zone. With the magnifying effects of climate change on the hydrological cycle the study of floodplain is becoming a key tool in the water management. Federal Emergency Management Agency has recently updated their floodplain standard as per the presidential executive order 2015 on …

Using Wavelet To Analyze Periodicities In Hydrologic Variables, Balbhadra Thakur, Pratik Pathak, Ajay Kalra, Sajjad Ahmad, Miguel Bernardez

Civil and Environmental Engineering and Construction Faculty Research

The trend and shift in the seasonal temperature, precipitation and streamflow time series across the Midwest have been analyzed, for the period 1960-2013, using the statistical analyses (Mann- Kendall test with and without considering short term persistence (MK2 and MK1, respectively) and Pettitt test). The paper also utilizes a relatively new approach, wavelet analysis, for testing the existence of trend and shift in the time series. The method has the ability to decompose a time series in to lower (trend) and higher frequency components (noise). Discrete wavelet transform (DWT) has been employed in the present study with an aim to …

Streamflow Pattern Variations Resulting From Future Climate Change In Middle Tianshan Mountains Region In China, Feiyun Zhang, Lanhai Li, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

In arid and semi-arid regions of North West china, glacier-melt, seasonal snowmelt and rainfall are the primary sources of flow in the rivers that originate from alpine areas. Spring and summer peak flow resulting from snowmelt and rainfall, respectively, are the main characteristics of streamflow pattern. Because of the damages caused by the spring and summer peak flow, a better understanding of the streamflow pattern variation under future climate warming is crucial. To analyze the variation of streamflow pattern under climate warming, the Kaidu River and the Manasi River watersheds in northern and southern slopes of Middle Tianshan Mountains, located …

Coupling Hec-Ras And Hec-Hms In Precipitation Runoff Modelling And Evaluating Flood Plain Inundation Map, Balbhadra Thakur, Ranjan Parajuli, Ajay Kalra, Sajjad Ahmad, Ritu Gupta

Civil and Environmental Engineering and Construction Faculty Research

The climate change and land use change have raised the challenges associated with increased runoff and flood management. The risks associated with flooding have been increasing with development in flood plain and changing climate resulting in increase in inundation of flood plain. The current study will help to evaluate the extent of flood plain in the study area – copper slough watershed (CSW) in Champaign, Illinois; utilizing the known precipitation and land use. The study of CSW is taken into account, as this is the largest watershed of Champaign City and had undergone major land use change increasing the flooding …

A Conceptualized Groundwater Flow Model Development For Integration With Surface Hydrology Model, Chao Chen, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

A groundwater system model was developed and calibrated in the study area of Lehman Creek watershed, eastern Nevada. The model development aims for integrating the surface hydrologic model - precipitation runoff modeling system (PRMS) model - with the three-dimensional (3D) finite-difference model MODFLOW. A two-layer groundwater model was developed with spatial discretization of 100 x 100 m grid. The water balance was estimated with inflows of gravity drainage and initial streamflow estimated from a calibrated PRMS model, and with outflows of spring discharges, boundary fluxes, and stream base flow. A steady-state model calibration was performed to estimate the hydraulic properties. …

An Investigation Of Geography And Climate Induced Distresses Patterns On Airfield Pavements At Us Air Force Installations, L K. Sahagun, M Karakouzian, A Paz-Cruz, H De La Fuente Mella

Civil and Environmental Engineering and Construction Faculty Research

This study investigated climate induced distresses patterns on airfield pavements at US Air Force installations. A literature review and surveys of Pavement Condition Index indicated that the predominant factor contributing to the development of pavement distress was climate. Results suggested that, within each type of pavement distress, a geographic pattern exists which is strongly correlated to conventional US climate zones. The US Air Force Roll-Up Database, housing over 50,000 records of pavement distress data, was distilled using a process designed to combine similar distresses while accounting for age and size of samples. The process reduced the data to a format …

Bridging Technical Skills Gaps Between High School Students And Local Employers, Edward C. Fletcher Jr., Will Tyson

Journal of Research in Technical Careers

The purpose of this study was to explore how technical skills taught and learned in Florida engineering and engineering technology-themed career academies fit technical skills desired by local employers in technology and manufacturing. The analysis utilized the narratives of 70 students and four teachers from career academies at four high schools and 27 industry leaders from the same geographical region of Florida. Data interpretation led to understanding that employers expressed an urgent need for technical skills using appropriate equipment and technologies, teachers were teaching students technical skills by simulating the real-world work environment, and students valued their abilities to transform …

Iowa Agricultural Educators’ Current And Perceived Grading Practices, Jenny Ann Lichty, Michael S. Retallick

Journal of Research in Technical Careers

Literature on grading reveals that grading practices have not changed much since they were first introduced. However, with alternative approaches, such as standards-based grading, being introduced, it is important to look at how agricultural educators are using grades to evaluate student learning. The purpose of this study was to determine the grading practices of Iowa high school agricultural educators. The accessible population consisted of 236 high school agricultural educators. Findings were based on responses of 157 (69.8%) educators who responded to the study via an online questionnaire. These agricultural educators used a variety of learning approaches, and their beliefs aligned …

Effects Of Integrating Mathematical Concepts Into A Nutrition Unit In The Animal Science Curriculum, Andrea R. Gardner, Brian K. Warnick, Rebecca G. Lawver

Journal of Research in Technical Careers

Achievement test scores in mathematics have been a concern among educators for many years. Teaching contextualized mathematics has been found to be effective and includes providing a direct application to real-life scenarios rather than teaching linear equations and algebraic principles in isolation. This study measured the effects of integrating mathematical skills in one instructional unit in an animal science curriculum. Students from eight schools participated in the research study. Students completed a pretest measuring their existing mathematical skills and self-efficacy in math. All students were taught a unit of instruction about animal nutrition and feeding. The control group received a …

College Of Engineering Senior Design Competition Spring 2017, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …