Physical Sciences and Mathematics Commons^™

Equivalency Of Indirect And Direct Potable Reuse Paradigms Based On A Quantitative Microbial Risk Assessment Framework, Erfaneh Amoueyan, Yongsheng He, Hongjie Wu, Chuanwei Zhu, Shichun Huang, Jian Huang

Civil and Environmental Engineering and Construction Faculty Research

Due to rapid growth in the potable reuse industry, there is a need to better characterize the associated pathogen risks and degree of attenuation achieved by various treatment trains. It is also important to understand how emerging treatment frameworks compare to the historical practice of de facto reuse. As such, the goals of this study were to (1) evaluate the equivalency of indirect potable reuse (IPR) and direct potable reuse (DPR) systems; (2) compare alternative treatment trains; and (3) identify the design components and operational conditions that are most critical to minimizing public health risks. To this end, we developed …

Superconductivity In The Van Der Waals Layered Compound Ps2, Yan-Ling Li, Elissaios Stavrou, Qiang Zhu, Samantha M. Clarke, Yunguo Li, Hong-Mei Huang

Physics & Astronomy Faculty Research

van der Waals (vdW) layered compounds provided a fruitful research platform for the realization of superconductivity. However, a vdW layered superconductor with a high transition temperature (Tc) at ambient conditions is still rare. Here, using variable-composition evolutionary structure predictions, we systematically explored the stable compounds in the P-S system up to 20 GPa. Opposed to the complex stoichiometries at ambient conditions, only one compound, PS2, is predicted to be thermodynamically stable above 8 GPa. Strikingly, PS2 is a vdW layered material isostructural to 3R−MoS2 exhibiting a predicted Tc of around 11 K at ambient pressure, both in the bulk and …

Non-Einstein Viscosity Phenomenon Of Acrylonitrile–Butadiene–Styrene Composites Containing Lignin–Polycaprolactone Particulates Highly Dispersed By High-Shear Stress, Sing-Hoon Kim, Kisuk Choi, Kyouk Ryeol Choi, Taesung Kim, Jonghwan Suhr, Kwang Jin Kim, Hyoung Jin Choi, Jae-Do Nam

Mechanical Engineering Faculty Research

Lignin powder was modified via ring-opening polymerization of caprolactone to form a lignin–polycaprolactone (LPCL) particulate. The LPCL particulates were mixed with an acrylonitrile–butadiene–styrene (ABS) matrix at an extremely high rotational speed of up to 3000 rpm, which was achieved by a closed-loop screw mixer and in-line melt extruder. Using this high-shear extruding mixer, the LPCL particulate size was controlled in the range of 3395 nm (conventional twin-screw extrusion) down to 638 nm (high-shear mixer of 3000 rpm) by altering the mixing speed and time. The resulting LPCL/ABS composites clearly showed non-Einstein viscosity phenomena, exhibiting reduced viscosity (2130 Pa·s) compared to …

Simulating Backward Wave Propagation In Metamaterial With Radial Basis Functions, Jichun Li, Bing Nan

Mathematical Sciences Faculty Research

In this paper we revisit the radial basis function (RBF) meshless method and implement it to solve the time-dependent Maxwell's equations in metamaterials. Numerical simulations of the backward wave propagation phenomena are successfully achieved using this RBF method with properly chosen free parameters in the RBFs.

Propagation Of A Short Grb Jet In The Ejecta: Jet Launching Delay Time, Jet Structure, And Gw170817/Grb 170817a, Jin-Jun Geng, Bing Zhang, Anders Kölligan, Rolf Kuiper, Yong-Feng Huang

Physics & Astronomy Faculty Research

We perform a series of relativistic magnetohydrodynamic simulations to investigate how a hot magnetic jet propagates within the dynamical ejecta of a binary neutron star merger, focusing on how the jet structure depends on the delay time of jet launching with respect to the merger time, Δt jet. We find that regardless of the jet-launching delay time, a structured jet with an angle-dependent luminosity and Lorentz factor is always formed after the jet breaks out of the ejecta. On the other hand, the jet-launching delay time has an impact on the jet structure. If the jet-launching delay time is relatively …

A Tight Relation Between Spiral Arm Pitch Angle And Protplanetary Disk Mass, Si-Yue Yu, Luis C. Ho, Zhaohuan Zhu

Physics & Astronomy Faculty Research

We use two-dimensional Fourier transformation to measure the pitch angle () of the dominant spiral Fourier mode of well-defined spiral arms in 13 protoplanetary disks, making use of near-infrared scattered-light images of AB Aur, SAO 206462, MWC 758, V1247 Ori, HD 142527, DZ Cha, LkHα 330, and HD 100453, and ALMA millimeter continuum images of Elias 2-27, IM Lup, AS 205, and HT Lup. We find that the measured pitch angle correlates strongly with disk mass (M D ), such that more massive protoplanetary disks have smaller pitch angles, following . Interestingly, four disks with a known companion (HD 142527, …

A Hard Look At Ngc 5347: Revealing A Nearby Compton-Thick Agn, E. S. Kammoun, J. M. Miller, A. Zoghbi, K. Oh, M. Koss, R. F. Muchotzky, L. W. Brenneman, W. N. Brandt, Daniel Proga, A. M. Lohfink, J. S. Kaastra, D. Barret, E. Behar, D. Stern

Physics & Astronomy Faculty Research

Current measurements show that the observed fraction of Compton-thick (CT) active galactic nuclei (AGN) is smaller than the expected values needed to explain the cosmic X-ray background. Prior fits to the X-ray spectrum of the nearby Seyfert-2 galaxy NGC 5347 (z = 0.00792, D = 35.5 Mpc ) have alternately suggested a CT and Compton-thin source. Combining archival data from Suzaku, Chandra, and—most importantly—new data from NuSTAR, ... See full text for complete abstract

Leadership’S Influence On Environmental Sustainability, Stallar Lufrano-Jardine

International Conference on Gambling & Risk Taking

A phenomenological study within the gaming industry is currently being conducted to determine influential indicators within business operations. Based on interviews of executive leadership at global companies, participants disclosed the environmental developments at their organization based on industry norms and the ability to develop/execute environmental initiatives. Four themes emerged: the leader’s ideology and the political climate; the company’s founding principles; support from the industry and/or within the company; and the ability to change industry dynamics. Each leader touched on these four points. Regardless of department type, level of leadership, and the desire to be globally conscious, all participants remarked on …

A Statistical Analysis Of The Roulette Martingale System: Examples, Formulas And Simulations With R, Peter Pflaumer

International Conference on Gambling & Risk Taking

Some gamblers use a martingale or doubling strategy as a way of improving their chances of winning. This paper derives important formulas for the martingale strategy, such as the distribution, the expected value, the standard deviation of the profit, the risk of a loss or the expected bet of one or multiple martingale rounds. A computer simulation study with R of the doubling strategy is presented. The results of doubling to gambling with a constant sized bet on simple chances (red or black numbers, even or odd numbers, and low (1 – 18) or high (19 – 36) numbers) and …

Controlling The Stereodynamics Of Cold Molecular Collisions, Balakrishnan Naduvalath, J. F. E. Croft, Meng Huang, Hua Guo

Chemistry and Biochemistry Faculty Research

We report numerically-exact quantum scattering calculations for low-energy collisions of quantum-state prepared HD with H2. Excellent agreement is obtained with recent measurements of Perreault et al. for the angular distribution of scattered HD at a collision energy of 1 K. By state-preparation of the HD molecules, control of the angular distribution of scattered HD was demonstrated. The stereo-dynamic control is achieved by the ability to choose a single or a coherent superposition of quantum states. We present a first-principles simulation of the experiment which enables us to attribute the main features of the observed angular distribution to a single L …

Kelly Fraction Estimation For Multiple Correlated Bets, William Chin

International Conference on Gambling & Risk Taking

It is well-known that expected portfolio growth is maximized by maximizing

expected logarithmic utility. This investment criterion is known as Kelly betting.

It has many optimality properties but is considered to be risky. Blackjack

teams and other advantage gamblers practice a fraction of the Kelly optimal to

decrease risk. Some hedge fund managers are thought to practice according to

Kelly principles. We use a continuous multivariate Geometric Brownian motion

model and present an interval estimate for the historical fraction for a portfolio

of correlated bets, possibly including a risk-free asset. Historical data comes

from a range of sources and the …

Nonstandard Dice That Both Count For Card Craps, Mark Bollman

International Conference on Gambling & Risk Taking

The Pala Casino in California deals Card Craps using a red die numbered {2; 2; 2; 5; 5; 5} and a blue die numbered {3; 3; 3; 4; 4; 4}. Two cards from a special 36-card deck, which contains one card bearing each of the 36 ways in which two dice can land when rolled, are dealt: one each face down to a red space and a blue space. When the dice are rolled, the higher number determines which of the cards is flipped over.

A moment's reflection reveals that Pala's blue die is unnecessary. The card selection process can …

One Solution To The Mass Budget Problem For Planet Formation: Optically Thick Disks With Dust Scattering, Zhaohuan Zhu, Shangjia Zhang, Yan-Fei Jiang, Akimasa Kataoka, Tilman Birnstiel, Cornelis P. Dullemond, Sean M. Andrews, Jane Huang, Laura M. Perez, John M. Carpenter, Xue-Ning Bai, David J. Wilner, Luca Ricci

Physics & Astronomy Faculty Research

Atacama Large Millimeter Array (ALMA) surveys have suggested that the dust in Class II disks may not be enough to explain the averaged solid mass in exoplanets, under the assumption that the mm disk continuum emission is optically thin. This optically thin assumption seems to be supported by recent Disk Substructures at High Angular Resolution Project (DSHARP) observations where the measured optical depths are mostly less than one. However, we point out that dust scattering can considerably reduce the emission from an optically thick region. If that scattering is ignored, an optically thick disk with scattering can be misidentified as …

Modeling The Light Curves Of The Luminous Type Ic Supernova 2007d, Shan-Qin Wang, Zach Cano, Long Li, Liang-Duan Liu, Ling-Jun Wang, Weikang Zheng, Zi-Gao Dai, En-Wei Liang, Alexei V. Filippenko

Physics & Astronomy Faculty Research

SN 2007D is a nearby (redshift z = 0.023146), luminous Type Ic supernova (SN) having a narrow light curve (LC) and high peak luminosity. Previous research based on the assumption that it was powered by the 56Ni cascade decay suggested that the inferred 56Ni mass and the ejecta mass are ~1.5 M ⊙ and ~3.5 M ⊙, respectively. In this paper, we employ some multiband LC models to model the R-band LC and the color (V − R) evolution of SN 2007D to investigate the possible energy sources powering them. We find that the pure 56Ni model is disfavored; the …

Relativistic Astronomy. Ii. In-Flight Solution Of Motion And Test Of Special Relativity Light Aberration, Jin-Ping Zhu, Bing Zhang, Yuan-Pei Yang

Physics & Astronomy Faculty Research

The Breakthrough Starshot project aims to send centimeter-sized, gram-scale "StarChip" probes to Alpha Centauri at a speed of ~0.2 c. On the other hand, Zhang & Li recently proposed that transrelativistic cameras may be sent to any direction to study astronomical objects and test special relativity. To conduct such "relativistic astronomy," one needs to solve the motion of the probe in flight. We solve the motion of the probe (including the moving direction and the velocity) by comparing the positions of three or more point sources observed in the Earth rest frame and in the probe's comoving frame. When the …

The Environmental Impact And Formation Of Meals From The Pilot Year Of A Las Vegas Convention Food Rescue Program, Samantha To, Courtney Coughenour, Jennifer Pharr

Environmental & Global Health Faculty Research

Annually, millions of tonnes of leftover edible foods are sent to landfill. Not only does this harm the environment by increasing the release of greenhouse gases which contribute to climate change, but it poses a question of ethics given that nearly 16 million households are food insecure in the US, and hundreds of millions of people around the globe. The purpose of this study was to document the amount of food diverted from landfill in the pilot year of a convention food rescue program and to determine the amount of greenhouse gas (GHG) emissions avoided by the diversion of such …

Cave Temperature And Management Implications In Lehman Caves, Great Basin National Park, Usa, Stanka Šebela, Gretchen Baker, Barbara Luke

Civil and Environmental Engineering and Construction Faculty Research

Cave air temperature was measured at six locations in Lehman Caves (USA) for one year at hourly intervals. Lehman is a show cave in a national park, treasured for its geological and biological resources. The two monitoring locations that are off of the tour route and, also, relatively distant from the cave’s entrances displayed nearly constant air temperature during the year. The other four sites, along the tour route, show daily temperature variation as well as annual fluctuation. After visitation levels decreased in the autumn, cave temperatures lagged but eventually reached an equilibrium which demonstrates recovery in the quiet winter. …

Cosmology-Independent Estimate Of The Fraction Of Baryon Mass In The Igm From Fast Radio Burst Observations, Zhengxiang Li, He Gao, Jun-Jie Wei, Yuan-Pei Yang, Bing Zhang, Zong-Hong Zhu

Physics & Astronomy Faculty Research

The excessive dispersion measure (DM) of fast radio bursts (FRBs) has been proposed to be a powerful tool to study intergalactic medium (IGM) and to perform cosmography. One issue is that the fraction of baryons in the IGM, f IGM, is not properly constrained. Here, we propose a method of estimating f IGM using a putative sample of FRBs with the measurements of both DM and luminosity distance d L. The latter can be obtained if the FRB is associated with a distance indicator (e.g., a gamma-ray burst or a gravitational-wave event), or the redshift z of the FRB is …

Pressure-Induced Phase Transition In 1,3,5-Triamino-2,4,6-Trinitrobenzene (Tatb), Brad A. Steele, Samantha M. Clarke, Matthew P. Kroonblawd, I-Feng W. Kuo, Philip F. Pagoria, Sergey N. Tkachev, Jesse S. Smith, Sorin Bastea, Laurence E. Fried, Joseph M. Zaug, Elissaios Stavrou, Oliver Tschauner

Geoscience Faculty Research

Determining the unreacted equation of state of 1,3, 5-triamino-2,4,6-trinitrobenzene (TATB) is challenging because it exhibits low crystal symmetry and low X-ray scattering strength. Here, we present the first high-pressure single-crystal X-ray diffraction (SXD) study of this material. Our SXD results reveal a previously unknown transition to a monoclinic phase above 4 GPa. No abrupt change of the volume occurs but the compressibility changes. Concomitant first principles evolutionary crystal structure prediction USPEX calculations confirm this transition and show that it involves a pressure-induced in-plane shift of the layers of TATB molecules with respect to the ambient-pressure phase.

Magnetic Borophenes From An Evolutionary Search, Meng-Hong Zhu, Xiao-Ji Weng, Guoying Gao, Shuai Dong, Ling-Fang Lin, Wei-Hua Wang, Qiang Zhu, Artem R. Oganov, Xiao Dong, Yongjun Tian, Xiang-Feng Zhou, Hui-Tian Wang

Physics & Astronomy Faculty Research

A computational methodology based on ab initio evolutionary algorithms and spin-polarized density functional theory was developed to predict two-dimensional magnetic materials. Its application to a model system borophene reveals an unexpected rich magnetism and polymorphism. A metastable borophene with nonzero thickness is an antiferromagnetic semiconductor from first-principles calculations, and can be further tuned into a half-metal by finite electron doping. In this borophene, the buckling and coupling among three atomic layers are not only responsible for magnetism, but also result in an out-of-plane negative Poisson's ratio under uniaxial tension, making it the first elemental material possessing auxetic and magnetic properties …

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.

High-Pressure High-Temperature Exploration Of Phase Boundaries Using Raman Spectroscopy, Jasmine Kashmir Hinton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Metastability of states can provide interesting properties that may not be readily accessible in a material’s ground state. Many materials show high levels of polymorphism, indicating a rich energy landscape and a potential for metastable states. Melt crystallization techniques provide a potential route to these states. We use a resistively heated diamond anvil cell (DAC) with fine control of a system’s pressure and temperature to explore these systems. Raman spectroscopy is used to track subtle structural changes across phase boundaries. Organic systems, such as glycine and aspirin, were our initial interest due to their high polymorphism and reported low melting …

Numerical Analysis And Fluid Flow Modeling Of Incompressible Navier-Stokes Equations, Tahj Hill

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Navier-Stokes equations (NSE) are an essential set of partial differential equations for governing the motion of fluids. In this paper, we will study the NSE for an incompressible flow, one which density ρ = ρ0 is constant.

First, we will present the derivation of the NSE and discuss solutions and boundary conditions for the equations. We will then discuss the Reynolds number, a dimensionless number that is important in the observations of fluid flow patterns. We will study the NSE at various Reynolds numbers, and use the Reynolds number to write the NSE in a nondimensional form.

We will …

Riding My Bike In Paradise With Margaret Fuller: A Phenomenological Study, Nanette Rasband Hilton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Margaret Fuller (1810-1850) was perhaps the most famous American woman during the nineteenth century. After her tragic death, reprints of her best-selling books were heavily edited and she was nearly forgotten. During and after her lifetime, Fuller fell victim to the phenomenological alterity identified and defined by theorists including Derrida and Edward Said as Othering. She spent her career combating Othering in all its forms. Through the lens of both social identity theory and multiple identity theory this study examines how Fuller grappled with social prescriptions. As an autodidact, she mined diverse literary resources to construct heterogeneous texts that cultivate …

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 …

K-Tuple Sampling From Partially Rank-Ordered Sets, Marvin Javier

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the introduction of Ranked Set Sampling (RSS), McIntyre (1952) demonstrated that using ranking information to select units for measurement can lead to estimators with reduced variance when compared to their counterparts based on a simple random sample of the same size. This is done by selecting a set of units, and without direct measurement, ranking the units in the set before identifying one unit for measurement. This ranking of the units can be done through judgement ranking (such as visual assessment), or by using a correlated auxiliary variable.

In its original form, RSS does not allow for ties when …

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 …