Physical Sciences and Mathematics Commons^™

Separation Of Neighboring Trivalent Lanthanides For Neutron Capture Cross Section Measurements, Balazs Jozsef Bene

UNLV Theses, Dissertations, Professional Papers, and Capstones

The determination of the low-energy neutron capture cross-section of 171Tm with greater accuracy is important for both astrophysics and Stockpile Stewardship. Thulium-171 is a branching point in the s-process of stellar nucleosynthesis. Branching point nuclei, with half-lives in the order of 1 – 100 years are places where neutron capture and beta decay competes. This isotope is also the second order (n, γ) reaction product of 169Tm, which was used as a radiochemical detector in nuclear weapon experiments. It was placed at strategic locations in nuclear devices. Following the test, samples were analyzed in the collected samples for products of …

An Examination Of The Community And Environmental Impact Of A Las Vegas Convention Food Rescue Program, Samantha H. To

UNLV Theses, Dissertations, Professional Papers, and Capstones

Food insecurity affects millions of Americans each year, inflicting negative consequences on the physical and mental health outcomes at all ages. Concurrently, millions of tons of leftover edible foods are sent to landfill each year. Not only does this pose a question of ethics, but increasingly harms the environment by misusing resources and increasing the release of

greenhouse gases.

Food rescue advisory meetings highlighted the need for more focused research to be conducted that assessed the impacts of donating rescued convention food on local environmental and community health. A mixed-method approach was used to detail the food rescue process between …

Petrology And Geochemistry Of The Enriched Poikilitic Shergottite Northwest Africa 10169: Insight Into The Martian Interior, Logan Matthew Combs

UNLV Theses, Dissertations, Professional Papers, and Capstones

The martian meteorite Northwest Africa (NWA) 10169 is classified as a new member of the geochemically enriched poikilitic shergottites, based on mineral composition, Lu-Hf isotope systematics, and rare earth element (REE) composition. Akin to other poikilitic shergottites, it shows a similar bimodal texture to other enriched and intermediate poikilitic shergottites. In addition, olivine and pyroxene in the poikilitic zone have higher Mg#’s (Mg/Mg+Fe) than those in the interstitial areas, suggesting that the poikilitic texture represents early-stage crystallization, opposed to late-stage non-poikilitic crystallization. Calculated fO2 values are reduced (FMQ -2.3 ± 0.23) within the poikilitic texture, and more oxidized (FMQ -1.07 …

Rapid Methods For Actinide And Strontium-89,90 Determination In Urban Matrices, Sherrod Maxwell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rapid radiochemical methods are needed to provide fast, reliable analytical measurements on a variety of different sample matrices in the case of a radiological event to protect the public, mitigate dose and protect the environment. If a radiological dispersive device (RDD), an Improvised Nuclear Device (IND) or a nuclear accident occurs, there will be an urgent need for quick analyses of urban matrices materials to support decision-making, dose mitigation and environmental clean-up. Since an incident involving a RDD or IND will likely occur in an urban or metropolitan area, it is very important to employ swift, robust analytical methods that …

Miocene-Quaternary Deformation Along The Central Maynard Lake Fault, Pahranagat Shear Zone, Nevada, Alexander Peck

UNLV Theses, Dissertations, Professional Papers, and Capstones

The left-lateral Pahranagat shear zone (PSZ) and Caliente-Enterprise zone (CEZ) exist at the boundary between two sub-provinces, the Northern (NBR) and Central Basin and Range (CBR). The PSZ contains three major ENE striking sinistral faults, including the Maynard Lake fault (MLF), which is the longest fault and marks the southern boundary of the zone. The PSZ has been suggested to be a transfer zone, but little is known about the structures along these major faults that are involved in strain transfer. These left-lateral systems exist within the Central Nevada seismic belt which has experienced significant earthquakes in recent history. Possible …

A Comparison Of The Product Topology On Two Trees With The Tree Topology On The Concatenation Of Two Trees, Katlyn Kathleen Cox

UNLV Theses, Dissertations, Professional Papers, and Capstones

A game tree is a nonempty set of sequences, closed under subsequences (i.e., if p ∈ T

and p extends q, then q ∈ T). If T is a game tree, then there is a natural topology on [T],

the set of paths through T. In this study we consider two types of topological spaces, both

constructed from game trees. The first is constructed by taking the Cartesian product of

two game trees, T and S: [T] × [S]. The second is constructed by the concatenation of two

game trees, T and S: [T ∗ S]. The goal of our …

Determination Of Anthropogenic Radionuclides In Ocean Water Using Extraction Chromatography, Jaimie Daum

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the aftermath of the reactor accident in Fukushima, it has become obvious that there is a severe lack in methods that would allow for the rapid determination of anthropogenic radionuclides in ocean water. Current radioanalytical techniques for the determination of radionuclides in natural waters have a number of disadvantages including the fact that they are time consuming, generate a substantial amount of waste, and are typically multi-step processes. Additionally, the elevated amount of dissolved ions in ocean water imparts a complex matrix that can interfere with the rapid separation and determination of anthropogenic radionuclides. Therefore, due to the size, …

Fundamental Tradeoffs In Estimation Of Finite-State Hidden Markov Models, Justin Le

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hidden Markov models (HMMs) constitute a broad and flexible class of statistical models that are widely used in studying processes that evolve over time and are only observable through the collection of noisy data. Two problems are essential to the use of HMMs: state estimation and parameter estimation. In state estimation, an algorithm estimates the sequence of states of the process that most likely generated a certain sequence of observations in the data. In parameter estimation, an algorithm computes the probability distributions that govern the time-evolution of states and the sampling of data. Although algorithms for the two problems are …

Structural Evolution And Regional Implications Of The Arrowhead Mine Fault Within The Pahranagat Shear Zone, Nevada, Usa, Michael Dennis Evans

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Basin and Range province is characterized by normal faults associated with

extension, but the occurrence of strike-slip faults and the seismic hazard accompanying

them is less understood. One major strike-slip zone, the Pahranagat shear zone (PSZ),

lies in Lincoln County, Nevada and within the boundary zone between northern Basin

and Range (NBR) and central Basin and Range (CBR) sub-provinces. The PSZ is a 20-

25 km long zone of Cenozoic left-lateral faults. The Arrowhead Mine Fault (AMF) is one

of the three major faults in the PSZ. The western AMF and the faults that surround and

abut it are …

Machine Learning Applications In Graduation Prediction At The University Of Nevada, Las Vegas, Elliott Collin Ploutz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Graduation rates of four-year institutions are an increasingly important metric to incoming students and for ranking universities. To increase completion rates, universities must analyze available student data to understand trends and factors leading to graduation. Using predictive modeling, incoming students can be assessed as to their likelihood of completing a degree. If students are predicted to be most likely to drop out, interventions can be enacted to increase retention and completion rates.

At the University of Nevada, Las Vegas (UNLV), four-year graduation rates are 15% and six-year graduation rates are 39%. To improve these rates, we have gathered seven years …

Use Of Sodium Bismuthate Chromatography For Separation Of Americium From Curium And Other Elements In Spent Nuclear Fuel, Jason Michael Richards

UNLV Theses, Dissertations, Professional Papers, and Capstones

A novel method for partitioning americium from curium has been developed using sodium bismuthate as both an oxidant and a separation medium. The presence of americium and curium in nuclear waste increases the heat load in geological repositories and leads to larger waste volumes. These elements are also the source of most of the long-term radiotoxicity of the waste. However, the heat load and long-term radiotoxicity contribution from americium is much greater than that from curium. The contribution of curium to the heat load and radiotoxicity of the waste is significant on the same time scale as longer-lived fission products …

Prostate Cancer Survival Among Hispanics: A Surveillance, Epidemiology, And End Results (Seer) Population-Based Cohort Study, David Rivas

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hispanics are now the youngest, largest, and fastest growing minority group in the U.S. Prostate cancer (PC) is the most commonly diagnosed cancer in men and is the second-leading cause of cancer deaths among Hispanics. For the first time, we examined PC-specific survival among distinct Hispanic groups that include Mexicans, Cubans, Dominicans, Puerto Ricans, as well as Central and South Americans. We compared these groups to the main reference population in the U.S., non-Hispanic Whites (NHW), after adjustment for prognostic factor risk categories (prostate-specific antigen (PSA) level, Gleason score, and tumor stage), as well as sociodemographic covariates (e.g., health insurance, …

Solvent Extraction And Extraction Chromatography Of Homologs And Pseudohomologs Of Rutherfordium Using Teha And Tehp, Jeffrey Rolfes

UNLV Theses, Dissertations, Professional Papers, and Capstones

Studies of the chemical properties of the heaviest elements have always been difficult due to the short half-lives and low cross sections involved. To solve this problem, atom-at-a-time methods are necessary to determine the properties of these short-lived isotopes. Extremely fast kinetics for the chemical reactions studied (on the same order as the nuclide’s half-life) are required, and the system should have the potential for automation. Solvent extraction, with its selectivity and quick kinetics, has historically been used for these investigations into characteristics of super heavy elements. Another technique, extraction chromatography, offers potentially a way of investigating rutherfordium’s properties, without …

Design On High Performance Nanoscale Cmos Circuits With Low Temperature Sensitivity, Ming Zhu

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the rapid development of integrated circuit (IC) design and manufacturing technology, the transistor size now can be shrunk into only couple of nanometers whereas billions of transistors can be squeezed into a square millimeter, providing unprecedented computation power. However, accompanied with continuous device miniaturization and increased integration density is the explosive growth of on-chip power dissipation and a wide range of temperature fluctuation, which can heavily and negatively affect the delay performance of the circuit, or in the worst case, the circuit may malfunction and the system can be unreliable. Therefore, improved performance resilience against temperature variations has become …

Bi-Directional Testing For Change Point Detection In Poisson Processes, Moinak Bhaduri

UNLV Theses, Dissertations, Professional Papers, and Capstones

Point processes often serve as a natural language to chronicle an event's temporal evolution, and significant changes in the flow, synonymous with non-stationarity, are usually triggered by assignable and frequently preventable causes, often heralding devastating ramifications. Examples include amplified restlessness of a volcano, increased frequencies of airplane crashes, hurricanes, mining mishaps, among others. Guessing these time points of changes, therefore, merits utmost care. Switching the way time traditionally propagates, we posit a new genre of bidirectional tests which, despite a frugal construct, prove to be exceedingly efficient in culling out non-stationarity under a wide spectrum of environments. A journey surveying …

Meshless Methods For Numerically Solving Boundary Value Problems Of Elliptic Type Partial Differential Equations, Minhwa Choi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this dissertation we propose and examine numerical methods for solving the boundary value problems of partial differential equations (PDEs) by meshless methods. First we aim at getting approximate particular solutions up of a nonhomogeneous equation by radial basis methods. For instance, the collocation method by radial basis functions (RBFs) for finding particular solutions is very popular in the literature. Now the particular solutions of certain important PDEs by RBF approximation are available with the order of convergence to the exact solutions provided. Here we explore and examine the numerical performances of these particular solutions in various examples. We then …

Algorithms For Tower Placement On Terrain, Binay Dahal

UNLV Theses, Dissertations, Professional Papers, and Capstones

We review existing algorithms for the placement of towers for illuminating 1.5D and 2.5D terrains. Finding the minimum number of towers of zero height to illuminate 1.5D terrain is known to be NP-Hard. We present approximation algorithms for solving two variations of the tower placement problem. In the first variation, we consider the placement of a single tower of given height to maximize visibility coverage. In the second variation, we consider the problem of placing reduced number of common height towers to cover the entire terrain. Algorithms for solving both problem variations are based on discretizing the problem domain by …

Elliptic Cryptosystem, Elizabeth Dettrey

UNLV Theses, Dissertations, Professional Papers, and Capstones

The elliptic cryptographic algorithm first presented in a paper by E. F. Dettrey and E. A. Yfantis is examined and explained in this thesis. The algorithm is based on the group operations of a set of points generated from an ellipse of arbitrary radii, and arbitrary center in the case of the generalized version, modulo a large prime. The security of the algorithm depends on the difficulty of solving a discrete logarithm in the groups used by this algorithm. While the elliptic cryptographic algorithm is not the most secure among the discrete logarithm based paradigm of cryptosystems for a given …

Larval-Ant Interactions In The Mojave Desert: Communication Brings Us Together, Alicia Mellor

UNLV Theses, Dissertations, Professional Papers, and Capstones

Butterflies are a diverse and essential group of pollinators whose abundance is predominantly determined by growth and survival of their larvae. In the family Lycaenidae, many species participate in a larval-ant mutualism where ants feed on nutrient-rich nectar produced by larvae and, in turn, protect those larvae from predators. Emerging evidence indicates larval scent in the form of cuticular hydrocarbons (CHCs), not nectar production, drives this interaction. This study takes two approaches to investigate CHCs as the driver behind the larval-ant mutualism in three butterfly species native to southern Nevada: Euphilotes bernardino martini (Martin’s blue), Brephidium exilis (western pygmy blue), …

A Machine Learning Approach To Predict First-Year Student Retention Rates At University Of Nevada, Las Vegas, Aditya Rajuladevi

UNLV Theses, Dissertations, Professional Papers, and Capstones

First-year student retention rates for a four-year institution refers to the percentage of First-time Full-time students from the previous fall who return to the same institution for the following fall. First-year retention rates act as an important indicator of the student satisfaction as well as the performance of the university. Moreover, universities with low retention rates may face a decline in the admissions of talented students with a notable loss of tuition fees and contributions from alumni. Therefore, it is important for universities to formulate strategies to identify students who are at risk of not being retained and take necessary …

A Novel Approach To Analyzing Strain Heterogeneity In Polycrystalline Quartz Specimens Deformed At High Pressure And Temperature, Nolan Ambrose Regis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rheological studies of rocks and minerals allow researchers to study the grain-scale deformation mechanisms that govern large-scale geologic processes from mountain building to mantle mixing. Deforming rock samples with high pressure and temperature apparatuses similar to the Griggs piston cylinder apparatus allows us to simulate deformation at depth. However, many apparatuses are limited to “cook-and-look” analysis and require modeling techniques to determine the evolution of deformation patterns found in experimental samples. A previous study used two-dimensional finite element models to analyze the development of stress and strain patterns in polycrystalline rocks. The study suggested rhythmic patterns in deformed rocks develop …

Applications Of Nanoporous Materials In Gas Separation And Storage, Amit Sharma

UNLV Theses, Dissertations, Professional Papers, and Capstones

Past decades in the field of gas separation and storage utilized the concepts of both cryogenic distillation and non-cryogenic methods such as high-pressure cylinders but few concerns – efficiency, energy intensiveness, cost associated, risk of failure always existed. Recent advances in the field focuses on using porous materials especially nanoporous materials. Nanoporous materials, due to their well-defined structure, range of pore diameters, and striking surface chemistry hold over traditional porous materials for gas separation and storage. With pore diameter less than 2 nm and abundance of energetically favorable sites (such as unsaturated metal sites, channels, cages, cavities etc.), these materials …

Notes On Linear Divisible Sequences And Their Construction: A Computational Approach, Sean Trendell

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this Masters thesis, we examine linear divisible sequences. A linear divisible sequence is any sequence {an}n≥0 that can be expressed by a linear homogeneous recursion relation that is also a divisible sequence. A sequence {an}n≥0 is called a divisible sequence if it has the property that if n|m, then an|am. A sequence of numbers {an}n≥0 is called a linear homogeneous recurrence sequence of order m if it can be written in the form

an+m = p1an+m−1 + p2an+m−2 + · · · + pm−1an+1 + pman, n ≥ 0,

for some constants p1, p2, ..., pm with pm = …

Holocene Climate Evolution Of Continental Western Eurasia Constrained By Stable-Isotope And Cation Geochemistry Of U-Th-Dated Speleothems And Meteogenic Travertine, Jonathan Lloyd Baker

UNLV Theses, Dissertations, Professional Papers, and Capstones

Reliable reconstructions of global and regional climate during the Holocene (11,700 years ago to present) are vital to constraining the natural range of climate variability and testing state-of-the-art models, which seek to forecast the near- and long-term impact of anthropogenic greenhouse forcing. Much of continental Eurasia is still underrepresented, however, in geological proxy reconstructions of Holocene climate variability, and the vast majority of paleoclimate data only reflect conditions during peak summer months (JJA) or the growing season. The paucity of winter proxy data has therefore been cited as a possible explanation for the current mismatch between geological proxy-based and climate-model …

Golden Arm: A Probabilistic Study Of Dice Control In Craps, Donald R. Smith, Robert Scott Iii

UNLV Gaming Research & Review Journal

This paper calculates how much control a craps shooter must possess on dice outcomes to eliminate the house advantage. A golden arm is someone who has dice control (or a rhythm roller or dice influencer). There are various strategies for dice control in craps. We discuss several possibilities of dice control that would result in several different mathematical models of control. We do not assert whether dice control is possible or not (there is a lack of published evidence). However, after studying casino-legal methods described by dice-control advocates, we can see only one realistic mathematical model that describes the resulting …

Methylated Dnmt1 And E2f1 Are Targeted For Proteolysis By L3mbtl3 And Crl4dcaf5 Ubiquitin Ligase, Feng Leng, Jiekai Yu, Chunxiao Zhang, Salvador Alejo, Nam Hoang, Hong Sun, Fei Lu, Hui Zhang

Chemistry and Biochemistry Faculty Research

Many non-histone proteins are lysine methylated and a novel function of this modification is to trigger the proteolysis of methylated proteins. Here, we report that the methylated lysine 142 of DNMT1, a major DNA methyltransferase that preserves epigenetic inheritance of DNA methylation patterns during DNA replication, is demethylated by LSD1. A novel methyl-binding protein, L3MBTL3, binds the K142-methylated DNMT1 and recruits a novel CRL4DCAF5 ubiquitin ligase to degrade DNMT1. Both LSD1 and PHF20L1 act primarily in S phase to prevent DNMT1 degradation by L3MBTL3-CRL4DCAF5. Mouse L3MBTL3/MBT-1 deletion causes accumulation of DNMT1 protein, increased genomic DNA methylation, and late embryonic lethality. …

Reply To 'Anisotropy Governs Strain Stiffening In Nanotwinned-Materials', Bing Li, Hong Sun, Changfeng Chen

Physics & Astronomy Faculty Research

No abstract provided.

Planetary Candidates Observed By Kepler. Viii. A Fully Automated Catalog With Measured Completeness And Reliability Based On Data Release 25, Susan E. Thompson, Jeffrey L. Coughlin, Kelssey Hoffman, Fergal Mullally, Jessie L. Christiansen, Christopher J. Burke, Steve Bryson, Natalie Batalha, Michael R. Haas, Joseph Catanzarite, Jason F. Rowe, Geert Barentsen, Douglas A. Caldwell, Bruce D. Clarke, Jon M. Jenkins, Jie Li, David W. Latham, Jack J. Lissauer, Savita Mathur, Robert L. Morris, Shawn E. Seader, Jeffrey C. Smith, Todd C. Klaus, Joseph D. Twicken, Jeffrey E. Van Cleve, Bill Wohler, Rachel Akeson, David R. Ciardi, William D. Cochran, Christopher E. Henze, Steve B. Howell

Physics & Astronomy Faculty Research

We present the Kepler Object of Interest (KOI) catalog of transiting exoplanets based on searching 4 yr of Kepler time series photometry (Data Release 25, Q1–Q17). The catalog contains 8054 KOIs, of which 4034 are planet candidates with periods between 0.25 and 632 days. Of these candidates, 219 are new, including two in multiplanet systems (KOI-82.06 and KOI-2926.05) and 10 high-reliability, terrestrial-size, habitable zone candidates. This catalog was created using a tool called the Robovetter, which automatically vets the DR25 threshold crossing events (TCEs). The Robovetter also vetted simulated data sets and measured how well it was able to separate …

Syntheses, Raman Spectroscopy And Crystal Structures Of Alkali Hexa-Fluoridorhenates(Iv) Revisited, James Louis-Jean, Samundeeswari Mariappan Balasekaran, Dean Smith, Ashkan Salamat, Chien Thang Pham, Frederic Poineau

Chemistry and Biochemistry Faculty Research

The A2[ReF6] (A = K, Rb and Cs) salts are isotypic and crystallize in the trigonal space group type P\overline{3}m1, adopting the K2[GeF6] structure type. Common to all A2[ReF6] structures are slightly distorted octa­hedral [ReF6]2− anions with an average Re—F bond length of 1.951 (8) Å. In those salts, symmetry lowering on the local [ReF6]2− anions from Oh (free anion) to D3d (solid-state structure) occur. The distortions of the [ReF6]2− anions, as observed in their Raman spectra, are correlated to the size of the counter-cations.

Management Of An Urban Stormwater System Using Projected Future Scenarios Of Climate Models: A Watershed-Based Modeling Approach, Ranjeet Thakali, Ajay Kalra, Sajjad Ahmad, Kamal Qaiser

Civil and Environmental Engineering and Construction Faculty Research

Anticipating a proper management needs for urban stormwater due to climate change is becoming a critical concern to water resources managers. In an effort to identify best management practices and understand the probable future climate scenarios, this study used high-resolution climate model data in conjunction with advanced statistical methods and computer simulation. Climate model data from the North American Regional Climate Change Assessment Program (NARCCAP) were used to calculate the design storm depths for the Gowan Watershed of Las Vegas Valley, Nevada. The Storm Water Management Model (SWMM), developed by the Environmental Protection Agency (EPA), was used for hydrological modeling. …