Physical Sciences and Mathematics Commons^™

Thermotropic Liquid-Crystalline And Light-Emitting Properties Of Poly(Pyridinium) Salts Containing Various Diamine Connectors And Hydrophilic Macrocounterions, Tae Soo Jo, Haesook Han, Pradip K. Bhowmik, Benoît Heinrich, Bertrand Donnio

Chemistry and Biochemistry Faculty Research

A set of poly(pyridinium) salts containing various diamine moieties, as molecular connectors, and poly(ethyleneglycol)-4-nonylphenyl-3-sulfopropyl ether, thereafter referred to as “Macroion”, as the hydrophilic counterion, were prepared by metathesis reaction from the respective precursory tosylated poly(pyridinium)s in methanol. The structure of these ionic polymers was established by spectroscopy and chromatography techniques. The shape-persistent ionic poly(pyridinium) materials, inserting rigid or semi-rigid diamine spacers, display thermotropic liquid-crystalline properties from room-temperature up to their isotropization (in the temperature range around 160–200 °C). The nature of the LC phases is lamellar in both cases as identified by the combination of various complementary experimental techniques including …

College Of Engineering Senior Design Competition Spring 2019, 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 …

On The Time-Frequency Downward Drifting Of Repeating Fast Radio Bursts, Weiyang Wang, Bing Zhang, Xuelei Chen, Renxin Xu

Physics & Astronomy Faculty Research

The newly discovered second repeating fast radio burst (FRB) source, FRB 180814.J0422+73, was reported to exhibit a time–frequency downward drifting pattern, which is also seen in the first repeater FRB 121102. We propose a generic geometrical model to account for the observed downward drifting of sub-pulse frequency, within the framework of coherent curvature radiation by bunches of electron–positron pairs in the magnetosphere of a neutron star (NS). A sudden trigger event excites these coherent bunches of charged particles, which stream outward along open field lines. As the field lines sweep across the line of sight, the bunches seen later travel …

Super Rapid Crystal Growth And Quench Of Monoclinic Bi-Ii* During Dynamic Compression, Zachary Allen Fussell

UNLV Theses, Dissertations, Professional Papers, and Capstones

We show that monoclinic Bi-II* forms during a dynamic compression regime with crystal growth rates from melt of ≈ 70 m/s. This extreme quench rate implies crystallization by non-diffusive processes and indicates that the liquid had a high degree of pre-ordering. Using ambient condition single crystal structure analysis we show for the first time that the monoclinic distorted phase of Bi (Bi-II) exists at ambient pressure, albeit bound to formation under dynamic compression. We review the pressure, temperature, and time conditions for formation and growth of this structure.

Telomeres, Nutrition And Mortality: Risk Factors For The Rate Of Telomere Length Decline And The Associations Between Telomere Length, Nutrition And Mortality, Saruna Ghimire

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Telomeres are nucleoprotein structures located at the ends of eukaryotic chromosomes, thought to protect the DNA from damage. As a person experiences stressors, harmful exposures, and other diseases throughout their life, telomeres are thought to become damaged and their length shortened, decreasing their ability to protect the DNA. Nutrition is an important aspect of healthy aging. Preservation of telomere length (TL) is thought to be one of the mechanisms by which good nutrition can delay or prevent the development of chronic disease and death. Recent evidence of preservation of TL with good nutrition is promising. Thus, the aim of …

Storing Iot Data Securely In A Private Ethereum Blockchain, Vinay Kumar Calastry Ramesh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Internet of Things (IoT) is a set of technologies that enable network-connected devices to perform an action or share data among several connected devices or to a shared database. The actions can be anything from switching on an Air Conditioning device remotely to turning on the ignition of a car through a command issued from a remote location or asking Alexa or Google Assistant to search for weather conditions in an area. IoT has proved to be game-changing for many industries such as Supply Chain, Shipping and Transportation providing updates on the status of shipments in real time. This has …

Equation Of State Of H2o Ice Using Melt-Recrystallization, Zachary Michael Grande

UNLV Theses, Dissertations, Professional Papers, and Capstones

The recent surge in exoplanet discoveries due to advancements in astrophysical technology and analysis has brought the reliability of early equation of state measurements into question as they are the limiting factor when modeling composition of these planets. H2O content is among the most important for the search of habitable planets as well as in understanding planetary dynamics and atmosphere formation. Over the last three decades the equation of state of H2O has been investigated with various techniques but, has suffered from anisotropic strain and poor powder statistics resulting in a large discrepancy in equation of state fits. At pressures …

Analysis Of Bitcoin Cryptocurrency And Its Mining Techniques, Suman Ghimire

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bitcoin is a peer-to-peer digital, decentralized cryptocurrency created by an individual under pseudonym Satoshi Nakamoto. In fact, it is the first digital, decentralized currency. Several developers and organizations have explored the importance of digital cryptocurrency and the concept of the blockchain. Bitcoin is assumed to be one of the secure and comfortable payment methods that can be used in the upcoming days. The backbone of Bitcoin mining is the concept of the blockchain, which is assumed to beone of the ingenious invention of this century. The blockchain is the collection of blocks that are linked together in such a way …

Effects Of Ecological Restoration Techniques In Glen Canyon National Recreation Area, Simone Ka-Voka Jackson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A better understanding of key ecological restoration techniques can inform land management in the Southwest on restoration options for areas infested by invasive grasses that can pose threats to ecosystems, from changes in nutrient cycling to altered fire regimes. In the semi-arid desert of Glen Canyon National Recreation Area (GLCA), several exotic grasses pose risks to local ecosystems: Saccharum ravennae, a relatively new invasive perennial grass, and Bromus rubens and Bromus tectorum, widespread annual grasses. In this study, multiple ecological restoration techniques were implemented to assess their effects on native and nonnative vegetation on sites invaded by the non-native grasses …

Specific Heat, Magnetic Susceptibility, And The Effect Of Pressure On Structural Properties And Valence Of Eumn2si2, Euco2si2, And Eu5in2sb6, Brian Edward Light

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many intermetallic solids containing elements from the rare earth series show interesting and unusual behavior associated with 4f electrons. This behavior includes unusual magnetic order, strongly correlated electrons, intermediate valence, heavy fermions, the Kondo effect, superconductivity, and non-Fermi liquid (NFL) to name a few. When long range magnetic order is suppressed to T = 0 K by the application of an external tuning parameter such as pressure, magnetic field, or chemical doping, a quantum critical point (QCP) appears in which strong quantum fluctuations give rise to many of the mentioned unusual properties.

Most of the past studies on unusual 4f …

Utilization Of Remote Sensing Data For Estimation Of The Groundwater Storage Variation, Gaurang Mistry

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater is the most extracted raw material, with an average withdrawal rate of 982 km3 per year, where 70 percent of the total groundwater withdrawn is used for agriculture globally (Margat & van der Gun, 2013). With climate change and increased water demands in recent years, monitoring the changes in the groundwater storage is of the utmost importance. This thesis presents an analysis that determines the rates, trends, and directions where groundwater storage is going in Pakistan. It also correlates fluctuations in groundwater storage with variations in precipitation and agricultural productivity in the country. The overall objectives of this thesis …

Effects Of Disturbance And Restoration Treatment On Fertile Islands In Lake Mead National Recreation Area, Camille Traylor

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disturbances by humans are one of the main drivers of change in contemporary desert ecosystems. Restoration treatments such as topsoil application and outplanting can be implemented in response to disturbances in order to maintain soil stability and a diverse plant community. Fertile islands - nutrient enriched areas beneath perennial shrubs - are fundamental features of deserts that can facilitate annual plant growth. A major uncertainty in desert ecology is how much time is required for fertile islands and nurse plant effects (the facilitation of one plant by another) to develop below maturing perennial plants. By studying naturally recruited perennial plants …

Batching Problems With Constraints, Shradha Kapoor

UNLV Theses, Dissertations, Professional Papers, and Capstones

There is an increasing demand for a phenomenon that can manifest benefits gained from grouping similar jobs together and then scheduling these groups efficiently. Batching is the decision of whether or not to put the jobs into same group based on certain criteria. Batching plays a major role in job scheduling in Information Technology, traffic controlling systems, and goods-flow management. A list batching problem refers to batching a list of jobs in the same order or priority as given in the problem.

In this thesis we consider a one-machine list batching problem under weighted average completion. Given sequence of jobs …

Benchmarking Permutation Flow Shop Problem: Adaptive And Enumerative Approaches Implementations Via Novel Threading Techniques, Hari Prasad Sapkota

UNLV Theses, Dissertations, Professional Papers, and Capstones

A large number of real-world planning problems are combinatorial optimization problems which are easy to state and have a finite but usually very large number of feasible solutions. The minimum spanning tree problem and the shortest path problem are some which are solvable through polynomial algorithms. Even though there are other problems such as crew scheduling, vehicle routing, production planning, and hotel room operations which have no properties such as to solve the problem with polynomial algorithms. All these problems are NP-hard. The permutation flow shop problem is also NP-hard problem and they require high computation. These problems are solvable …

An Analysis Of Postmastectomy Breast Reconstruction Due To Breast Cancer In Nevada And The United States From 2008-2013, Jenna Webb

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: In the United States, female breast cancer was the leading cause of new cancer cases from 2011-2015. Since the Women’s Health and Cancer Act of 1998 (WHCRA), the federal government mandates employee and private health insurance providers to cover breast reconstruction if they cover mastectomies. Postmastectomy breast reconstruction (PBR) rates increased after the WHCRA, but these rates have remained relatively low throughout recent years. Objective: The objective of this study was to determine factors associated with women having PBR due to breast cancer in Nevada and the United States from 2008 to 2013. Methods: Using two HCUP database, NIS …

Acr Accreditation For Utah Valley Hospital’S Radiation Oncology Center, Remy Manigold

UNLV Theses, Dissertations, Professional Papers, and Capstones

Becoming an accredited clinic through the American College of Radiology (ACR) and their Radiation Oncology Practice Accreditation (ROPA) program will provide third-party evaluation of patient care to ensure the best treatment possible for patients.

Talk of getting ACR accreditation has occurred in the past for Utah Valley Hospital/American Fork Hospital, but at the time it was seen as something that did not provide sufficient value vs. the cost. The recent One Intermountain restructuring is intended to unify all of the Intermountain Healthcare radiation oncology centers in Utah so the Radiation Oncology Director has set the goal that all Intermountain radiation …

The Effects Of Injury On Running Status And Gait Biomechanics, Kristyne Wiegand

UNLV Theses, Dissertations, Professional Papers, and Capstones

Over the past several decades, endurance running has grown steadily as a popular form of physical activity. Running is easily accessible, does not require expensive equipment, and can be performed without specific skill training. Individuals who run also experience health benefits like increased cardiovascular health and reduced risk of all-cause morbidity. Despite these benefits, running is also associated with high rates of musculoskeletal injury. Although researchers have attempted to identify injury risks and mitigate the incidence of running injury, there is still no consensus as to why runners become injured. Research has also attempted to identify biomechanical movement patterns that …

Machine Learning Prediction Of Primary Tissue Origin Of Cancer From Gene Expression Read Counts, Lohitha Chintham Reddy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells. Generally, manufacturing of proteins by cells is controlled by genes. Each gene must have the correct instructions for making its protein, so that it allows the protein to perform the correct function for the cell. When one or more genes in a cell mutate and create an abnormal protein, that is when cancer begins. An abnormal protein provides different information compared to a normal protein. This can cause cells to multiply uncontrollably and cause cancer.

RNA sequencing (RNA-seq) can be used to figure out …

Approximation Algorithms For Illuminating 1.5d Terrain, Jiwan Khatiwada

UNLV Theses, Dissertations, Professional Papers, and Capstones

We review important algorithmic results for the coverage of 1.5D terrain by point guards. Finding the minimum number of point guards for covering 1.5D terrain is known to be NP-hard. We propose two approximation algorithms for covering 1.5D terrain by a fewer number of point guards. The first algorithm (Greedy Ranking Algorithm) is based on ranking vertices in term of number of visible edges from them. The second algorithm (Greedy Forward Marching Algorithm) works in greedy manner by scanning the terrain from left to right. Both algorithms are implemented in Python 2.7 programming language.

Generalized And Higher Dimensional Apollonian Packings, Daniel Lautzenheiser

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we show that circle, sphere, and higher dimensional sphere packings may

be realized as subsets of the boundary of hyperbolic space, subject to certain symmetry

conditions based on a discrete group of motions of the hyperbolic space. This leads to

developing and applying counting methods which admit rigorous upper and lower bounds on

the Hausdorff (or Besikovitch) dimension of the residual set of several generalized Apollonian

circle packings. We find that this dimension (which also coincides with the critical exponent

of a zeta-type function) of each packing is strictly greater than that of the Apollonian

packing, supporting …

Assessing Minimal-Input Restoration Strategies For Desert Soil And Vegetation Restoration, Audrey Jean Rader

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mojave and Sonoran Deserts have been negatively impacted by anthropogenic disturbances. Considering that these ecosystems may recover on millennial timescales, research has shown that restoration techniques can be fairly successful in initiating long-term recovery processes in these sensitive environments. However, uncertainty remains as to which techniques are effective in different circumstances, such as in different climates or across different soil properties, and which techniques may best avoid unintended consequences, such as facilitating non-native plants. To reduce fugitive dust as a human health hazard, increase soil stability, and enhance wildlife habitat, further work is necessary to develop restoration techniques for …

Generating Kernel Aware Polygons, Bibek Subedi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Problems dealing with the generation of random polygons has important applications for evaluating the performance of algorithms on polygonal domain. We review existing algorithms for generating random polygons. We present an algorithm for generating polygons admitting visibility properties. In particular, we propose an algorithm for generating polygons admitting large size kernels. We also present experimental results on generating such polygons.

Assessing Simulated Transmissivity In Numerical Flow Models Of Complex Hydrogeology, Afan Tarar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Accurately extracting a meaningful transmissivity, a target value within one order of magnitude of field estimates, in numerical models poses a significant challenge when modeling complex groundwater systems. Aquifer transmissivity is directly proportional to the aquifer thickness and the estimated aquifer hydraulic conductivity. In complex geologic conditions (especially in fractured systems) with multiple heterogeneous and anisotropic hydrogeologic units, transmissivity can vary over several orders of magnitude.

To extract a meaningful value of transmissivity from a numerical model, a simple five-layer MODFLOW model was constructed. Each layer in the model was assigned a fixed hydraulic conductivity and thickness. The model simulates …

Multi-Resolution Spatio-Temporal Change Analyses Of Hydro-Climatological Variables In Association With Large-Scale Oceanic-Atmospheric Climate Signals, Kazi Ali Tamaddun

UNLV Theses, Dissertations, Professional Papers, and Capstones

The primary objective of the work presented in this dissertation was to evaluate the change patterns, i.e., a gradual change known as the trend, and an abrupt change known as the shift, of multiple hydro-climatological variables, namely, streamflow, snow water equivalent (SWE), temperature, precipitation, and potential evapotranspiration (PET), in association with the large-scale oceanic-atmospheric climate signals. Moreover, both observed datasets and modeled simulations were used to evaluate such change patterns to assess the efficacy of the modeled datasets in emulating the observed trends and shifts under the influence of uncertainties and inconsistencies. A secondary objective of this study was to …

Beyond Genetics: Addressing Activity In Microbial Ecology, Scott Christopher Thomas

UNLV Theses, Dissertations, Professional Papers, and Capstones

The field of microbial ecology is on the cusp of another revolution, one that uses synergy to address the limitations of previous studies. My dissertation is representative of the new era of research to come, through combining the latest technological advances with established classical methods to provide a more complete understanding of microbial ecosystems. In my first study, I evaluate the conservation of central carbon metabolic pathways and activity along a temperature and diversity gradient (60-95 ℃) through the use of 16S rRNA gene amplicon data, metagenome sequencing, and position-specific 13C-labeled metabolite probing. In my second study, I provide the …

The Affective Perceptual Model: Enhancing Communication Quality For Persons With Pimd, Jadin Tredup

UNLV Theses, Dissertations, Professional Papers, and Capstones

Methods for prolonged compassionate care for persons with Profound Intellectual and Multiple Disabilities (PIMD) require a rotating cast of import people in the subjects life in order to facilitate interaction with the external environment. As subjects continue to age, dependency on these people increases with complexity of communications while the quality of communication decreases. It is theorized that a machine learning (ML) system could replicate the attuning process and replace these people to promote independence. This thesis extends this idea to develop a conceptual and formal model and system prototype.

The main contributions of this thesis are: (1) proposal of …

Classification Of Vegetation In Aerial Imagery Via Neural Network, Gevand Balayan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis focuses on the task of trying to find a Neural Network that is best suited for identifying vegetation from aerial imagery. The goal is to find a way to quickly classify items in an image as highly likely to be vegetation(trees, grass, bushes and shrubs) and then interpolate that data and use it to mark sections of an image as vegetation. This has practical applications as well. The main motivation of this work came from the effort that our town takes in conserving water. By creating an AI that can easily recognize plants, we can better monitor the …

Petrogenesis Of Unusual Occurrence Of Amphibole Asbestos In Mohave County, Arizona And Clark County, Nevada, Tomoyo Austin

UNLV Theses, Dissertations, Professional Papers, and Capstones

The term “asbestos” applies to six types of fibrous amphiboles or chrysotile with specific morphologies that are commercially mined and processed. Inhaling asbestos fibers is known to cause many negative health effects, including mesothelioma, several different cancers, various respiratory diseases and non-respiratory diseases, and fatalities. The recent years, several cases of non-occupational exposure to asbestos fibers raised an awareness of environmental exposure to naturally occurring asbestos (NOA) which refers to asbestiform minerals that fall out of the regulatory definition of asbestos.

There are two sources of NOA in the area, Wilson Ridge pluton, AZ, and Boulder City pluton, NV which …

A Novel Feature Maps Covariance Minimization Approach For Advancing Convolutional Neural Network Performance, Bikram Basnet

UNLV Theses, Dissertations, Professional Papers, and Capstones

We present a method for boosting the performance of the Convolutional Neural Network (CNN) by reducing the covariance between the feature maps of the convolutional layers.

In a CNN, the units of a hidden layer are segmented into the feature/activation maps. The units within a feature map share the weight matrix (filter), or in simple terms look for the same feature. A feature map is the output of one filter applied to the previous layer. CNN search for features such as straight lines, and as these features are spotted, they get reported to the feature map. During the learning process, …

Machine Learning Approach For Prediction Of Bone Mineral Density And Fragility Fracture In Osteoporosis, Bibek Bhattarai

UNLV Theses, Dissertations, Professional Papers, and Capstones

Osteoporosis is a prevailing bone disease, which weakens the bone and is one of the

major factors of disability, especially in elderly persons. In this thesis, we developed

various machine learning models to predict fracture risk of osteoporosis. These mod-

els were built to base their predictions on genotype and phenotype data of patients.

We performed two dierent types of analysis: fracture risk prediction (a classica-

tion model) and bone mineral density (BMD) prediction (a regression model). For

fracture risk prediction we implemented four dierent algorithms: logistic regression,

random forest, gradient boosting, and multi-layer perceptron (MLP) based on dier-

ent …