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Full-Text Articles in Physical Sciences and Mathematics

The Simulated Biological Response To Southern Ocean Eddies Via Biological Rate Modification And Physical Transport, Tyler Rohr, Cheryl S. Harrison, Matthew C. Long, Peter Gaube, Scott C. Doney Apr 2020

The Simulated Biological Response To Southern Ocean Eddies Via Biological Rate Modification And Physical Transport, Tyler Rohr, Cheryl S. Harrison, Matthew C. Long, Peter Gaube, Scott C. Doney

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

We examine the structure and drivers of anomalous phytoplankton biomass in Southern Ocean eddies tracked in a global, multiyear, eddy-resolving, 3-D ocean simulation of the Community Earth System Model.We examine how simulated anticyclones and cyclones differentially modify phytoplankton biomass concentrations, growth rates, and physical transport. On average, cyclones induce negative division rate anomalies that drive negative net population growth rate anomalies, reduce dilution across shallower mixed layers, and advect biomass anomalously downward via eddy-induced Ekman pumping. The opposite is true in anticyclones. Lateral transport is dominated by eddy stirring rather than eddy trapping. The net effect on anomalous biomass can …


A (2+1)-Dimensional Sine-Gordon And Sinh-Gordon Equations With Symmetries And Kink Wave Solutions, Gangwei Wang, Kaitong Yang, Haicheng Gu, Fei Guan, A. H. Kara Apr 2020

A (2+1)-Dimensional Sine-Gordon And Sinh-Gordon Equations With Symmetries And Kink Wave Solutions, Gangwei Wang, Kaitong Yang, Haicheng Gu, Fei Guan, A. H. Kara

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, a (2+1)-dimensional sine-Gordon equation and a sinh-Gordon equation are derived from the well-known AKNS system. Based on the Hirota bilinear method and Lie symmetry analysis, kink wave solutions and travelingwave solutions of the (2+1)-dimensional sine-Gordon equation are constructed. The traveling wave solutions of the (2+1)-dimensional sinh-Gordon equation can also be provided in a similar manner. Meanwhile, conservation laws are derived.


Analysis Of The Healthcare Mers-Cov Outbreak In King Abdulaziz Medical Center, Riyadh, Saudi Arabia, June–August 2015 Using A Seir Ward Transmission Model, Tamer Oraby, Michael G. Tyshenko, Hanan H. Balkhy, Yasar Tasnif, Adriana Quiroz-Gaspar, Zeinab Mohamed, Ayesha Araya, Susie Elsaadany, Eman Al-Mazroa, Mohammed A. Alhelail, Yaseen M. Arabi, Mustafa Al-Zoughool Apr 2020

Analysis Of The Healthcare Mers-Cov Outbreak In King Abdulaziz Medical Center, Riyadh, Saudi Arabia, June–August 2015 Using A Seir Ward Transmission Model, Tamer Oraby, Michael G. Tyshenko, Hanan H. Balkhy, Yasar Tasnif, Adriana Quiroz-Gaspar, Zeinab Mohamed, Ayesha Araya, Susie Elsaadany, Eman Al-Mazroa, Mohammed A. Alhelail, Yaseen M. Arabi, Mustafa Al-Zoughool

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging zoonotic coronavirus that has a tendency to cause significant healthcare outbreaks among patients with serious comorbidities. We analyzed hospital data from the MERS-CoV outbreak in King Abdulaziz Medical Center, Riyadh, Saudi Arabia, June–August 2015 using the susceptible-exposed-infectious-recovered (SEIR) ward transmission model. The SEIR compartmental model considers several areas within the hospital where transmission occurred. We use a system of ordinary differential equations that incorporates the following units: emergency department (ED), out-patient clinic, intensive care unit, and hospital wards, where each area has its own carrying capacity and distinguishes the transmission by …


Gw190425: Observation Of A Compact Binary Coalescence With Total Mass ∼ 3.4 M⊙, B. P. Abbott, R. Abbott, T. D. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, Wenhui Wang, Adam Zadrozny Mar 2020

Gw190425: Observation Of A Compact Binary Coalescence With Total Mass ∼ 3.4 M⊙, B. P. Abbott, R. Abbott, T. D. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, Wenhui Wang, Adam Zadrozny

Physics and Astronomy Faculty Publications and Presentations

On 2019 April 25, the LIGO Livingston detector observed a compact binary coalescence with signal-to-noise ratio 12.9. The Virgo detector was also taking data that did not contribute to detection due to a low signal-to-noise ratio, but were used for subsequent parameter estimation. The 90% credible intervals for the component masses range from to (– if we restrict the dimensionless component spin magnitudes to be smaller than 0.05). These mass parameters are consistent with the individual binary components being neutron stars. However, both the source-frame chirp mass and the total mass of this system are significantly larger than those of …


Integer Versus Fractional Order Seir Deterministic And Stochastic Models Of Measles, Md Rafiul Islam, Angela Peace, Daniel Medina, Tamer Oraby Mar 2020

Integer Versus Fractional Order Seir Deterministic And Stochastic Models Of Measles, Md Rafiul Islam, Angela Peace, Daniel Medina, Tamer Oraby

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, we compare the performance between systems of ordinary and (Caputo) fractional differential equations depicting the susceptible-exposed-infectious-recovered (SEIR) models of diseases. In order to understand the origins of both approaches as mean-field approximations of integer and fractional stochastic processes, we introduce the fractional differential equations (FDEs) as approximations of some type of fractional nonlinear birth and death processes. Then, we examine validity of the two approaches against empirical courses of epidemics; we fit both of them to case counts of three measles epidemics that occurred during the pre-vaccination era in three different locations. While ordinary differential equations (ODEs) …


Loop-Closure Kinetics Reveal A Stable, Right-Handed Dna Intermediate In Cre Recombination, Massa J. Shoura, Stefan M. Giovan, Alexandre A. Vetcher, Riccardo Ziraldo, Andreas Hanke, Stephen D. Levene Mar 2020

Loop-Closure Kinetics Reveal A Stable, Right-Handed Dna Intermediate In Cre Recombination, Massa J. Shoura, Stefan M. Giovan, Alexandre A. Vetcher, Riccardo Ziraldo, Andreas Hanke, Stephen D. Levene

Physics and Astronomy Faculty Publications and Presentations

In Cre site-specific recombination, the synaptic intermediate is a recombinase homotetramer containing a pair of loxP DNA target sites. The enzyme system's strand-exchange mechanism proceeds via a Holliday-junction (HJ) intermediate; however, the geometry of DNA segments in the synapse has remained highly controversial. In particular, all crystallographic structures are consistent with an achiral, planar Holliday-junction (HJ) structure, whereas topological assays based on Cre-mediated knotting of plasmid DNAs are consistent with a right-handed chiral junction. We use the kinetics of loop closure involving closely spaced (131–151 bp) loxP sites to investigate the in-aqueo ensemble of conformations for the longest-lived looped DNA …


Phylogeography Of Acartia Tonsa Dana, 1849 (Calanoida: Copepoda) And Phylogenetic Reconstruction Of The Genus Acartia Dana, 1846, Nicole J. Figueroa, Diego F. Figueroa, David Hicks Mar 2020

Phylogeography Of Acartia Tonsa Dana, 1849 (Calanoida: Copepoda) And Phylogenetic Reconstruction Of The Genus Acartia Dana, 1846, Nicole J. Figueroa, Diego F. Figueroa, David Hicks

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The calanoid copepod, Acartia tonsa Dana, 1849 is one of the most abundant and well-studied estuarian species with a worldwide distribution. In this research, we use the mitochondrial cytochrome oxidase subunit I gene to study the phylogeography of A. tonsa by analyzing sequences from specimens collected in the western Gulf of Mexico (GOM) along with all sequences from previous research. We reconstruct the phylogeny for the genus Acartia Dana, 1846 and highlight numerous potential misidentifications of Acartia species deposited in GenBank. The incorrect taxonomy assigned to some of these sequences results in apparently paraphyletic relationships. This study demonstrates that A. …


Introductory Chapter: Dynamical Symmetries And Quantum Chaos, Paul Bracken Mar 2020

Introductory Chapter: Dynamical Symmetries And Quantum Chaos, Paul Bracken

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

No abstract provided.


Privateex: Privacy Preserving Exchange Of Crypto-Assets On Blockchain, Lei Xu, Lin Chen, Zhimin Gao, Keshav Kasichainula, Miguel Fernandez, Bogdan Carbunar, Weidong Shi Mar 2020

Privateex: Privacy Preserving Exchange Of Crypto-Assets On Blockchain, Lei Xu, Lin Chen, Zhimin Gao, Keshav Kasichainula, Miguel Fernandez, Bogdan Carbunar, Weidong Shi

Computer Science Faculty Publications and Presentations

Bitcoin introduces a new type of cryptocurrency that does not rely on a central system to maintain transactions. Inspired by the success of Bitcoin, all types of alt cryptocurrencies were invented in recent years. Some of the new cryptocurrencies focus on privacy enhancement, where transaction information such as value and sender/receiver identity can be hidden, such as Zcash and Monero. However, there are few schemes to support multiple types of cryptocurrencies/assets and offer privacy enhancement at the same time. The major challenge for a multiple asset system is that it needs to support two-way assets exchange between participants besides one-way …


Domain Adaptation For Vehicle Detection In Traffic Surveillance Images From Daytime To Nighttime, Jinlong Ji, Zhigang Xu, Hongkai Yu, Lan Fu, Xuesong Zhou Mar 2020

Domain Adaptation For Vehicle Detection In Traffic Surveillance Images From Daytime To Nighttime, Jinlong Ji, Zhigang Xu, Hongkai Yu, Lan Fu, Xuesong Zhou

Computer Science Faculty Publications and Presentations

Vehicle detection in traffic surveillance images is an important approach to obtain vehicle data and rich traffic flow parameters. Recently, deep learning based methods have been widely used in vehicle detection with high accuracy and efficiency. However, deep learning based methods require a large number of manually labeled ground truths (bounding box of each vehicle in each image) to train the Convolutional Neural Networks (CNN). In the modern urban surveillance cameras, there are already many manually labeled ground truths in daytime images for training CNN, while there are little or much less manually labeled ground truths in nighttime images. In …


Subsea 2019 Expedition To The Gorda Ridge, Darlene S. S. Lim, Nicole A. Raineault, John A. Breier, Eric W. Chan, Josh Chernov, Tamar Cohen, Matthew Deans, Angela Garcia, Christopher R. German, Michelle Hauer Mar 2020

Subsea 2019 Expedition To The Gorda Ridge, Darlene S. S. Lim, Nicole A. Raineault, John A. Breier, Eric W. Chan, Josh Chernov, Tamar Cohen, Matthew Deans, Angela Garcia, Christopher R. German, Michelle Hauer

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The SUBSEA (Systematic Underwater Biogeochemical Science and Exploration Analog) program blends ocean exploration with “ocean worlds” research, along with NASA analog and work studies research, to address science, science operations, and technology knowledge gaps related to the exploration of our solar system. The science group researches venting fluids at isolated seamounts and spreading ridges in the Pacific Ocean as analog environments to putative volcanically hosted hydrothermal systems on other “ocean worlds” (defined as places in the outer solar system that could possess subsurface oceans). The science operations research group studies E/V Nautilus architecture, distributed teams, communication, and lowlatency telerobotics. The …


Lack Of Debye And Meissner Screening In Strongly Magnetized Quark Matter At Intermediate Densities, Bo Feng, Efrain J. Ferrer, Israel Portillo Mar 2020

Lack Of Debye And Meissner Screening In Strongly Magnetized Quark Matter At Intermediate Densities, Bo Feng, Efrain J. Ferrer, Israel Portillo

Physics and Astronomy Faculty Publications and Presentations

We study the static responses of cold quark matter in the intermediate baryonic density region (characterized by a chemical potential μ) in the presence of a strong-magnetic field. We consider in particular, the so-called magnetic dual Chiral Density Wave (MDCDW) phase, which is materialized by an inhomogeneous condensate formed by a particle-hole pair. It is shown, that the MDCDW phase is more stable in the weak-coupling regime than the one considered in the magnetic catalysis of chiral symmetry braking phenomenon and even than the chiral symmetric phase that was expected to be realized at sufficiently high baryonic chemical potential. The …


Optimal Control With Manf Treatment Of Photoreceptor Degeneration, Erika T. Camacho, Suzanne Lenhart, Luis A. Melara, M. Cristina Villalobos, Stephen Wirkus Mar 2020

Optimal Control With Manf Treatment Of Photoreceptor Degeneration, Erika T. Camacho, Suzanne Lenhart, Luis A. Melara, M. Cristina Villalobos, Stephen Wirkus

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

People afflicted with diseases such as retinitis pigmentosa and age-related macular degeneration experience a decline in vision due to photoreceptor degeneration, which is currently unstoppable and irreversible. Currently there is no cure for diseases linked to photoreceptor degeneration. Recent experimental work showed that mesencephalic astrocyte-derived neurotrophic factor (MANF) can reduce neuron death and, in particular, photoreceptor death by reducing the number of cells that undergo apoptosis. In this work, we build on an existing system of ordinary differential equations that represent photoreceptor interactions and incorporate MANF treatment for three experimental mouse models having undergone varying degrees of photoreceptor degeneration. Using …


Optimal Quantization Via Dynamics, Joseph Rosenblatt, Mrinal Kanti Roychowdhury Mar 2020

Optimal Quantization Via Dynamics, Joseph Rosenblatt, Mrinal Kanti Roychowdhury

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Quantization for probability distributions refers broadly to estimating a given probability measure by a discrete probability measure supported by a finite number of points. We consider general geometric approaches to quantization using stationary processes arising in dynamical systems, followed by a discussion of the special cases of stationary processes: random processes and Diophantine processes. We are interested in how close stationary process can be to giving optimal n-means and nth optimal mean distortion errors. We also consider different ways of measuring the degree of approximation by quantization, and their advantages and disadvantages in these different contexts.


Application Of Acoustical Remote Sensing Techniques For Ecosystem Monitoring Of A Seagrass Meadow, Megan S. Ballard, Kevin M. Lee, Jason D. Sagers, Gabriel R. Venegas, Andrew R. Mcneese, Preston S. Wilson, Abdullah Rahman Mar 2020

Application Of Acoustical Remote Sensing Techniques For Ecosystem Monitoring Of A Seagrass Meadow, Megan S. Ballard, Kevin M. Lee, Jason D. Sagers, Gabriel R. Venegas, Andrew R. Mcneese, Preston S. Wilson, Abdullah Rahman

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Seagrasses provide a multitude of ecosystem services and serve as important organic carbon stores. However, seagrass habitats are declining worldwide, threatened by global climate change and regional shifts in water quality. Acoustical methods have been applied to assess changes in oxygen production of seagrass meadows since sound propagation is sensitive to the presence of bubbles, which exist both within the plant tissue and freely floating the water as byproducts of photosynthesis. This work applies acoustic remote sensing techniques to characterize two different regions of a seagrass meadow: a densely vegetated meadow of Thalassia testudinum and a sandy region sparsely populated …


Group Vibrational Mode Assignments As A Broadly Applicable Tool For Characterizing Ionomer Membrane Structure As A Function Of Degree Of Hydration, Neili Loupe, Khaldoon Abu-Hakmeh, Shuitao Gao, Luis Gonzalez, Matthew Ingargiola, Kayla Mathiowetz, Ryan Cruse, Jonathan Doan, Isaiah Salas, Nicholas Dimakis Feb 2020

Group Vibrational Mode Assignments As A Broadly Applicable Tool For Characterizing Ionomer Membrane Structure As A Function Of Degree Of Hydration, Neili Loupe, Khaldoon Abu-Hakmeh, Shuitao Gao, Luis Gonzalez, Matthew Ingargiola, Kayla Mathiowetz, Ryan Cruse, Jonathan Doan, Isaiah Salas, Nicholas Dimakis

Physics and Astronomy Faculty Publications and Presentations

Infrared spectra of Nafion, Aquivion, and the 3 M membrane were acquired during total dehydration of fully hydrated samples. Fully hydrated exchange sites are in a sulfonate form with a C3V local symmetry. The mechanical coupling of the exchange site to a side chain ether link gives rise to vibrational group modes that are classified as C3V modes. These mode intensities diminish concertedly with dehydration. When totally dehydrated, the sulfonic acid form of the exchange site is mechanically coupled to an ether link with no local symmetry. This gives rise to C1 group modes that …


Supporting Blockchain-Based Cryptocurrency Mobile Payment With Smart Devices, Lei Xu, Lin Chen, Zhimin Gao, Larry Carranco, Xinxin Fan, Nolah Shah Feb 2020

Supporting Blockchain-Based Cryptocurrency Mobile Payment With Smart Devices, Lei Xu, Lin Chen, Zhimin Gao, Larry Carranco, Xinxin Fan, Nolah Shah

Computer Science Faculty Publications and Presentations

The smart device owning rate such as smart phone and smart watch is higher than ever before and mobile payment has become one of the major payment methods in many different areas. At the same time, blockchain-based cryptocurrency is becoming a nonnegligible type of currency and the total value of all types of cryptocurrency has reached USD 200 billion. Therefore, it is a natural demand to support cryptocurrency payment on mobile devices. Considering the poor infrastructure and low penetration of financial service in developing countries, this combination is especially attractive. The high storage cost and payment processing latency are the …


Spanning Properties Of Theta-Theta-6, Mirela Damian, John Iacono, Andrew Winslow Feb 2020

Spanning Properties Of Theta-Theta-6, Mirela Damian, John Iacono, Andrew Winslow

Computer Science Faculty Publications and Presentations

We show that, unlike the Yao–Yao graph YY6, the Theta–Theta graph ΘΘ6 defined by six cones is a spanner for sets of points in convex position. We also show that, for sets of points in non-convex position, the spanning ratio of ΘΘ6 is unbounded.


Crazy Sequential Representations Of Numbers For Small Bases, Tim Wylie Feb 2020

Crazy Sequential Representations Of Numbers For Small Bases, Tim Wylie

Computer Science Faculty Publications and Presentations

Throughout history, recreational mathematics has always played a prominent role in advancing research. Following in this tradition, in this paper we extend some recent work with crazy sequential representations of numbers− equations made of sequences of one through nine (or nine through one) that evaluate to a number. All previous work on this type of puzzle has focused only on base ten numbers and whether a solution existed. We generalize this concept and examine how this extends to arbitrary bases, the ranges of possible numbers, the combinatorial challenge of finding the numbers, efficient algorithms, and some interesting patterns across any …


The Role Of The Asymmetric Ekman Dissipation Term On The Energetics Of The Two-Layer Quasi-Geostrophic Model, Eleftherios Gkioulekas Feb 2020

The Role Of The Asymmetric Ekman Dissipation Term On The Energetics Of The Two-Layer Quasi-Geostrophic Model, Eleftherios Gkioulekas

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In the two-layer quasi-geostrophic model, the friction between the flow at the lower layer and the surface boundary layer, placed beneath the lower layer, is modeled by the Ekman term, which is a linear dissipation term with respect to the horizontal velocity at the lower layer. The Ekman term appears in the governing equations asymmetrically; it is placed at the lower layer, but does not appear at the upper layer. A variation, proposed by Phillips and Salmon, uses extrapolation to place the Ekman term between the lower layer and the surface boundary layer, or at the surface boundary layer. We …


Classification Of Radial Solutions To Equations Related To Caffarelli–Kohn–Nirenberg Inequalities, John Villavert Feb 2020

Classification Of Radial Solutions To Equations Related To Caffarelli–Kohn–Nirenberg Inequalities, John Villavert

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

This article studies the qualitative and quantitative properties of radial solutions to an elliptic equation related to the Euler–Lagrange equations for certain sharp Caffarelli–Kohn–Nirenberg inequalities. Namely, we examine the equation

−div(|x|aDu)=|x|bup, u>0, in RN, where p>1, N≥2, N−2+a≥0 and b>−N. The main results establish the properties of radially symmetric solutions including existence, uniqueness, and classification results as well as results on the asymptotic and intersecting behaviour of such solutions.


Delaunay Surfaces Expressed In Terms Of A Cartan Moving Frame, Paul Bracken Feb 2020

Delaunay Surfaces Expressed In Terms Of A Cartan Moving Frame, Paul Bracken

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Delaunay surfaces are investigated by using a moving frame approach. These surfaces correspond to surfaces of revolution in the Euclidean three-space. A set of basic one-forms is defined. Moving frame equations can be formulated and studied. Related differential equation which depend on variables relevant to the surface are obtained. For the case of minimal and constant mean curvature surfaces, the coordinate functions can be calculated in closed form. In the case in which the mean curvature is constant, these functions can be expressed in terms of Jacobi elliptic functions.


Td-Dft Spin-Adiabats With Analytic Nonadiabatic Derivative Couplings, Nicole Bellonzi, Ethan Alguire, Shervin Fatehi, Yihan Shao, Joseph E. Subotnik Jan 2020

Td-Dft Spin-Adiabats With Analytic Nonadiabatic Derivative Couplings, Nicole Bellonzi, Ethan Alguire, Shervin Fatehi, Yihan Shao, Joseph E. Subotnik

Chemistry Faculty Publications and Presentations

We present an algorithm for efficient calculation of analytic nonadiabatic derivative couplings between spin-adiabatic, time-dependent density functional theory states within the Tamm-Dancoff approximation. Our derivation is based on the direct differentiation of the Kohn-Sham pseudowavefunction using the framework of Ou et al. Our implementation is limited to the case of a system with an even number of electrons in a closed shell ground state, and we validate our algorithm against finite difference at an S1/T2 crossing of benzaldehyde. Through the introduction of a magnetic field spin-coupling operator, we break time-reversal symmetry to generate complex valued nonadiabatic derivative …


Implications Of Different Nitrogen Input Sources For Potential Production And Carbon Flux Estimates In The Coastal Gulf Of Mexico (Gom) And Korean Peninsula Coastal Waters, Jongsun Kim, Piers Chapman, Gilbert Rowe, Steven F. Dimarco, Daniel C. O. Thornton Jan 2020

Implications Of Different Nitrogen Input Sources For Potential Production And Carbon Flux Estimates In The Coastal Gulf Of Mexico (Gom) And Korean Peninsula Coastal Waters, Jongsun Kim, Piers Chapman, Gilbert Rowe, Steven F. Dimarco, Daniel C. O. Thornton

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The coastal Gulf of Mexico (GOM) and coastal sea off the Korean Peninsula (CSK) both suffer from human-induced eutrophication. We used a nitrogen (N) mass balance model in two different regions with different nitrogen input sources to estimate organic carbon fluxes and predict future carbon fluxes under different model scenarios. The coastal GOM receives nitrogen predominantly from the Mississippi and Atchafalaya rivers and atmospheric nitrogen deposition is only a minor component in this region. In the CSK, groundwater and atmospheric nitrogen deposition are more important controlling factors. Our model includes the fluxes of nitrogen to the ocean from the atmosphere, …


Monitoring Of The Radio Galaxy M 87 During A Low-Emission State From 2012 To 2015 With Magic, V. A. Acciari, S. Ansoldi, Juan P. Madrid Jan 2020

Monitoring Of The Radio Galaxy M 87 During A Low-Emission State From 2012 To 2015 With Magic, V. A. Acciari, S. Ansoldi, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

M87 is one of the closest (z = 0.004 36) extragalactic sources emitting at very high energies (VHE, E > 100 GeV). The aim of this work is to locate the region of the VHE gamma-ray emission and to describe the observed broad-band spectral energy distribution (SED) during the low VHE gamma-ray state. The data fromM87 collected between 2012 and 2015 as part of aMAGIC monitoring programme are analysed and combined with multiwavelength data from Fermi-LAT, Chandra, HST, EVN, VLBA, and the Liverpool Telescope. The averaged VHE gamma-ray spectrum can be fitted from ∼100 GeV to ∼10 TeV with a simple …


Impact Of The Next Gen Pet Curriculum On Science Identity, Robynne M. Lock, Ben Van Dusen, Steven Maier, Liang Zeng Jan 2020

Impact Of The Next Gen Pet Curriculum On Science Identity, Robynne M. Lock, Ben Van Dusen, Steven Maier, Liang Zeng

Physics and Astronomy Faculty Publications and Presentations

The Next Gen Physical Science and Everyday Thinking (PET) curriculum was designed for physical science courses for future elementary teachers. However, this curriculum may also be used in general education conceptual science courses. The materials are aligned with the Next Generation Science Standards and use a guided-inquiry approach. Next Gen PET is currently being implemented at many universities nationwide. We examine the impact of this curriculum on students’ science identities at a subset of these universities. The identity framework consists of three dimensions. Recognition is the extent to which a student believes that parents, peers, and professors view them as …


Electrospinning Piezoelectric Fibers For Biocompatible Devices, Bahareh Azimi, Mario Milazzo, Andrea Lazzeri, Stefano Berrettini, M. Jasim Uddin, Zhao Qin, Markus J. Buehler, Serena Danti Jan 2020

Electrospinning Piezoelectric Fibers For Biocompatible Devices, Bahareh Azimi, Mario Milazzo, Andrea Lazzeri, Stefano Berrettini, M. Jasim Uddin, Zhao Qin, Markus J. Buehler, Serena Danti

Chemistry Faculty Publications and Presentations

The field of nanotechnology has been gaining great success due to its potential in developing new generations of nanoscale materials with unprecedented properties and enhanced biological responses. This is particularly exciting using nanofibers, as their mechanical and topographic characteristics can approach those found in naturally occurring biological materials. Electrospinning is a key technique to manufacture ultrafine fibers and fiber meshes with multifunctional features, such as piezoelectricity, to be available on a smaller length scale, thus comparable to subcellular scale, which makes their use increasingly appealing for biomedical applications. These include biocompatible fiber-based devices as smart scaffolds, biosensors, energy harvesters, and …


Tailoring The Viscosity Of Water And Ethylene Glycol Based Tio2 Nanofluids, Abu Musa Abdullah, Aminur Rashid Chowdhury, Yingchen Yang, Horacio Vasquez, Justin Moore, Jason Parsons, Karen Lozano, Jose J. Gutierrez, Karen S. Martirosyan, Mohammed Uddin Jan 2020

Tailoring The Viscosity Of Water And Ethylene Glycol Based Tio2 Nanofluids, Abu Musa Abdullah, Aminur Rashid Chowdhury, Yingchen Yang, Horacio Vasquez, Justin Moore, Jason Parsons, Karen Lozano, Jose J. Gutierrez, Karen S. Martirosyan, Mohammed Uddin

Chemistry Faculty Publications and Presentations

Highlights

  • Viscosity of TiO2 nanofluid at variable physical parameters has been reviewed.

  • Classical and experimental viscosity models of nanofluids have been discussed.

  • Preparation techniques of TiO2 nanofluid have been discussed.

  • Viscosity of TiO2 nanofluid can increase by 329 times compared to the base fluid.

  • Viscosity of TiO2 nanofluid decreases significantly with increasing temperature.

Abstract

Nanofluids have garnered significant attention in the scientific and engineering research communities due to their enhanced heat transfer properties when compared to conventional thermal fluids. Nanofluids comprised of titanium dioxide (TiO2) nanoparticles have a wide range of applications due to their excellent thermophysical properties like thermal …


Agricultural And Environmental Weeds Of South Texas And Their Management, Pushpa Soti, John A. Goolsby, Alexis Racelis Jan 2020

Agricultural And Environmental Weeds Of South Texas And Their Management, Pushpa Soti, John A. Goolsby, Alexis Racelis

Biology Faculty Publications and Presentations

The Lower Rio Grande Valley (LRGV) in south Texas is one of the most productive agricultural regions in southern United States. With subtropical climate and highly fertile soils, this region provides a year-round growing condition for crops. Along with citrus, major crops grown in the region are sorghum cotton and corn in the summer and vegetables in winter. Thus, a fallow period of 3-6 months between successive crops is common in the region. Growers in this region report weeds as their number one economic and agronomic problem affecting crop yield and quality and increasing the cost of production and weeds …


Lysyl-Trna Synthetase From Pseudomonas Aeruginosa: Characterization And Identification Of Inhibitory Compounds, Samantha Balboa, Yanmei Hu, Frank B. Dean, James M. Bullard Jan 2020

Lysyl-Trna Synthetase From Pseudomonas Aeruginosa: Characterization And Identification Of Inhibitory Compounds, Samantha Balboa, Yanmei Hu, Frank B. Dean, James M. Bullard

Chemistry Faculty Publications and Presentations

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial infections and has highly developed systems for acquiring resistance against numerous antibiotics. The gene (lysS) encoding P. aeruginosa lysyl-tRNA synthetase (LysRS) was cloned and overexpressed, and the resulting protein was purified to 98% homogeneity. LysRS was kinetically evaluated, and the Km values for the interaction with lysine, adenosine triphosphate (ATP), and tRNALys were determined to be 45.5, 627, and 3.3 µM, respectively. The kcatobs values were calculated to be 13, 22.8, and 0.35 s−1, resulting in kcatobs/KM values of 0.29, 0.036, and 0.11 s−1µM−1, …