Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Texas Rio Grande Valley

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 451 - 480 of 2419

Full-Text Articles in Physical Sciences and Mathematics

Which Countries Are Leading High-Impact Science In Astronomy?, Juan P. Madrid, Julie Steen Oct 2022

Which Countries Are Leading High-Impact Science In Astronomy?, Juan P. Madrid, Julie Steen

Physics and Astronomy Faculty Publications and Presentations

Recent news reports claim that China is overtaking the United States and all other countries in scientific productivity and scientific impact. A straightforward analysis of high-impact papers in astronomy reveals that this is not true in our field. In fact, the United States continues to host, by a large margin, the authors that lead high-impact papers. Moreover, this analysis shows that 90% of all high-impact papers in astronomy are led by authors based in North America and Europe. That is, only about 10% of countries in the world host astronomers that publish “astronomy’s greatest hits".


Streaming Algorithms For Multitasking Scheduling With Shared Processing, Bin Fu, Yumei Huo, Hairong Zhao Oct 2022

Streaming Algorithms For Multitasking Scheduling With Shared Processing, Bin Fu, Yumei Huo, Hairong Zhao

Computer Science Faculty Publications and Presentations

In this paper, we design the first streaming algorithms for the problem of multitasking scheduling on parallel machines with shared processing. In one pass, our streaming approximation schemes can provide an approximate value of the optimal makespan. If the jobs can be read in two passes, the algorithm can find the schedule with the approximate value. This work not only provides an algorithmic big data solution for the studied problem, but also gives an insight into the design of streaming algorithms for other problems in the area of scheduling.


Study Of Multilayer Flow Of A Bi-Viscous Bingham Fluid Sandwiched Between Hybrid Nanofluid In A Vertical Slab With Nonlinear Boussinesq Approximation, Mahanthesh Basavarajappa, Shruthy Myson, Kuppalapalle Vajravelu Oct 2022

Study Of Multilayer Flow Of A Bi-Viscous Bingham Fluid Sandwiched Between Hybrid Nanofluid In A Vertical Slab With Nonlinear Boussinesq Approximation, Mahanthesh Basavarajappa, Shruthy Myson, Kuppalapalle Vajravelu

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Bi-Viscosity Bingham plastic fluids are used to understand the rheological characteristics of pigment-oil suspensions, polymeric gels, emulsions, heavy oil, etc. High-temperature applications in many industrial and engineering problems, linear density-temperature variation is inadequate to describe convective heat transport. Therefore, the characteristics of the nonlinear convective flow of a Bi-Viscosity Bingham Fluid (BVBF) through three layers in a vertical slab are studied. The two outer layers of the oil-based hybrid nanofluid and the intermediate layer of BVBF are considered. The thermal buoyancy force is governed by the nonlinear Boussinesq approximation. Continuity of heat flux, velocity, shear stress, and temperature are imposed …


The Spectral Picture And Joint Spectral Radius Of The Generalized Spherical Aluthge Transform, Chafiq Benhida, Raul E. Curto, Sang Hoon Lee, Jasang Yoon Oct 2022

The Spectral Picture And Joint Spectral Radius Of The Generalized Spherical Aluthge Transform, Chafiq Benhida, Raul E. Curto, Sang Hoon Lee, Jasang Yoon

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

For an arbitrary commuting d--tuple $\bT$ of Hilbert space operators, we fully determine the spectral picture of the generalized spherical Aluthge transform $\dbT$ and we prove that the spectral radius of $\bT$ can be calculated from the norms of the iterates of $\dbT$. \ Let $\bm{T} \equiv (T_1,\cdots,T_d)$ be a commuting d--tuple of bounded operators acting on an infinite dimensional separable Hilbert space, let P:=T∗1T1+⋯+T∗dTd−−−−−−−−−−−−−−−√, and let ⎛⎝⎜⎜T1⋮Td⎞⎠⎟⎟=⎛⎝⎜⎜V1⋮Vd⎞⎠⎟⎟P be the canonical polar decomposition, with (V1,⋯,Vd) a (joint) partial isometry and ⋂i=1dkerTi=⋂i=1dkerVi=kerP. \medskip For 0≤t≤1, we define the generalized spherical Aluthge transform of $\bm{T}$ by \Delta_t(\bm{T}):=(P^t V_1P^{1-t}, \cdots, P^t V_dP^{1-t}). We …


Recent Advances In Computational Study And Design Of Mof Catalysts For Co2 Conversion, Haoyuan Chen Oct 2022

Recent Advances In Computational Study And Design Of Mof Catalysts For Co2 Conversion, Haoyuan Chen

Chemistry Faculty Publications and Presentations

Catalytic conversion of the greenhouse gas CO2 into value-added chemicals and fuels is highly beneficial to the environment, the economy, and the global energy supply. Metal–organic frameworks (MOFs) are promising catalysts for this purpose due to their uniquely high structural and chemical tunability. In the catalyst discovery process, computational chemistry has emerged as an essential tool as it can not only aid in the interpretation of experimental observations but also provide atomistic-level insights into the catalytic mechanism. This Mini Review summarizes recent computational studies on MOF-catalyzed CO2 conversion through different types of reactions, discusses about the usage of various computational …


Comparative Analysis Of All-Terrain Vehicles, Motorcycle And Automobile-Related Trauma In A Rural Border Community Of The Usa, Haissam S. Elzaim, Kristina Vatcheva, Annelyn Torres-Reveron, Gregery Pequeno, Monica Michelle Betancourt-Garcia Oct 2022

Comparative Analysis Of All-Terrain Vehicles, Motorcycle And Automobile-Related Trauma In A Rural Border Community Of The Usa, Haissam S. Elzaim, Kristina Vatcheva, Annelyn Torres-Reveron, Gregery Pequeno, Monica Michelle Betancourt-Garcia

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Introduction: There is widespread use of all-terrain vehicles (ATVs) in the USA for both work-related and recreational activities. In this study, we aimed to determine the difference in injury severity, Glasgow Coma scales and length of stay between ATV-related injuries and injuries sustained from motorcycles (MOTOs) and automobiles (AUTOs).

Methods: We retrospectively analysed ATV, MOTO and AUTO injuries from a Level 2 Trauma Center between 01 January 2015 and 31 August 2020. Proportional odds regression analyses, as well as multivariable regression models, were used to analyse the data.

Results: There were significantly more male and paediatric patients that suffered ATV-related …


Optimal Quantization For Some Triadic Uniform Cantor Distributions With Exact Bounds, Mrinal Kanti Roychowdhury Oct 2022

Optimal Quantization For Some Triadic Uniform Cantor Distributions With Exact Bounds, Mrinal Kanti Roychowdhury

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Let {Sj:1≤j≤3} be a set of three contractive similarity mappings such that Sj(x)=rx+j−12(1−r) for all x∈R, and 1≤j≤3, where 0

Let {Sj:1≤j≤3}">{Sj:1≤j≤3}{Sj:1≤j≤3} be a set of three contractive similarity mappings such that Sj(x)=rx+j−12(1−r)">Sj(x)=rx+j−12(1−r)Sj(x)=rx+j−12(1−r) for all x∈R">x∈Rx∈R, and 1≤j≤3">1≤j≤31≤j≤3, where 0P has support the Cantor set generated by the similarity mappings Sj">SjSj for 1≤j≤3">1≤j≤31≤j≤3. Let r0=0.1622776602">r0=0.1622776602r0=0.1622776602, and r1=0.2317626315">r1=0.2317626315r1=0.2317626315 (which are ten digit rational approximations of two real numbers). In this paper, for 00n-means and the nth quantization errors for the triadic uniform Cantor distribution P for all positive integers n≥2">n≥2n≥2. Previously, …


Combined Effects Of Scarification, Phytohormones, Stratification, And Soil Type On The Germination And/Or Seedling Performance Of Three Tamaulipan Thornscrub Forest Species, Paula Luera, Christopher A. Gabler Oct 2022

Combined Effects Of Scarification, Phytohormones, Stratification, And Soil Type On The Germination And/Or Seedling Performance Of Three Tamaulipan Thornscrub Forest Species, Paula Luera, Christopher A. Gabler

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

Tamaulipan thornforests in south Texas and northeast Mexico are a conservation hotspot. Shortages of native seedlings limit regional restoration and are largely driven by knowledge gaps regarding propagation of the 75+ thornforest species planted during restorations. We previously investigated three thornforest species with low or inconsistent germination or seedling survival: Ebenopsis ebano (Fabaceae), Cordia boissieri (Boraginaceae), and Zanthoxylum fagara (Rutaceae), and identified the types and dosages of chemical seed treatments that maximized germination. However, chemical treatments were performed in isolation and combinational treatments may be required to break dormancy or maximize germination. This study builds on prior work by investigating …


On Equivariant Flag F-Vectors For Balanced Relative Simplicial Complexes, Jacob A. White Oct 2022

On Equivariant Flag F-Vectors For Balanced Relative Simplicial Complexes, Jacob A. White

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We study the equivariant flag f-vector and equivariant flag h-vector of a balanced relative simplicial complex with respect to a group action. When the complex satisfies Serre's condition (Sℓ), we show that the equivariant flag h-vector, the equivariant h-vector, and the equivariant f-vector satisfy several inequalities.
We apply these results to the study of P-partitions of double posets, and weak colorings of mixed graphs.


Diffraction-Free Beam Propagation At The Exceptional Point Of Non-Hermitian Glauber Fock Lattices, Cem Yuce, Hamidreza Ramezani Oct 2022

Diffraction-Free Beam Propagation At The Exceptional Point Of Non-Hermitian Glauber Fock Lattices, Cem Yuce, Hamidreza Ramezani

Physics and Astronomy Faculty Publications and Presentations

We construct localized beams in a non-Hermitian Glauber Fock (NGF) lattice of coupled waveguides and show that they can propagate for a long distance without almost no diffraction. We specifically obtain the diffraction-free beams in a finite NGF lattice at the exceptional point (EP) by using the exact eigenstates of the semi-infinite unidirectional NGF lattice. We provide a numerical approach to finding other lattices that are capable of supporting non-diffracting beams at EPs.


A Mesh-Free Method Using Piecewise Deep Neural Network For Elliptic Interface Problems, Cuiyu He, Xiaozhe Hu, Lin Mu Oct 2022

A Mesh-Free Method Using Piecewise Deep Neural Network For Elliptic Interface Problems, Cuiyu He, Xiaozhe Hu, Lin Mu

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, we propose a novel mesh-free numerical method for solving the elliptic interface problems based on deep learning. We approximate the solution by the neural networks and, since the solution may change dramatically across the interface, we employ different neural networks for each sub-domain. By reformulating the interface problem as a least-squares problem, we discretize the objective function using mean squared error via sampling and solve the proposed deep least-squares method by standard training algorithms such as stochastic gradient descent. The discretized objective function utilizes only the point-wise information on the sampling points and thus no underlying mesh …


Saturable Absorption Of Free-Electron Laser Radiation By Graphite Near The Carbon K-Edge, Lars Hoffmann, Sasawat Jamnuch, Craig P. Schwartz, Tobias Helk, Sumana L. Raj, Hikaru Mizuno, Riccardo Mincigrucci, Laura Foglia, Emiliano Principi, Shervin Fatehi Sep 2022

Saturable Absorption Of Free-Electron Laser Radiation By Graphite Near The Carbon K-Edge, Lars Hoffmann, Sasawat Jamnuch, Craig P. Schwartz, Tobias Helk, Sumana L. Raj, Hikaru Mizuno, Riccardo Mincigrucci, Laura Foglia, Emiliano Principi, Shervin Fatehi

Chemistry Faculty Publications and Presentations

The interaction of intense light with matter gives rise to competing nonlinear responses that can dynamically change material properties. Prominent examples are saturable absorption (SA) and two-photon absorption (TPA), which dynamically increase and decrease the transmission of a sample depending on pulse intensity, respectively. The availability of intense soft X-ray pulses from free-electron lasers (FELs) has led to observations of SA and TPA in separate experiments, leaving open questions about the possible interplay between and relative strength of the two phenomena. Here, we systematically study both phenomena in one experiment by exposing graphite films to soft X-ray FEL pulses of …


On A Novel Approach To The Thermogravimetric Analysis Of Polymers: Polystyrene, Mircea Chipara, Karen Lozano, Dorina M. Chipara, Carlos Delgado, Victoria Padilla Sep 2022

On A Novel Approach To The Thermogravimetric Analysis Of Polymers: Polystyrene, Mircea Chipara, Karen Lozano, Dorina M. Chipara, Carlos Delgado, Victoria Padilla

Physics and Astronomy Faculty Publications and Presentations

A novel equation that describes the temperature dependence of the residual mass fraction (as determined by thermogravimetric analysis) is derived, assuming that the dependence of the residual mass fraction on temperature has a sigmoidal shape. The equation allows the estimation of the sigmoidal activation energy solely from the experimental data at a single heating rate. The consistency with the isoconversional approach and the relationship between the Ozawa and sigmoidal activation energies are reported. The equation was successfully tested by the thermal degradation of atactic polystyrene at various heating rates. Both the thermograms and their derivatives are analyzed in detail.


Using Low-Cost Sensors To Assess Pm2.5 Concentrations At Four South Texan Cities On The U.S.—Mexico Border, Esmeralda Mendez, Owen Temby, Dawid K. Wladyka, Katarzyna Sepielak, Amit U. Raysoni Sep 2022

Using Low-Cost Sensors To Assess Pm2.5 Concentrations At Four South Texan Cities On The U.S.—Mexico Border, Esmeralda Mendez, Owen Temby, Dawid K. Wladyka, Katarzyna Sepielak, Amit U. Raysoni

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

Low-cost sensors have been used considerably to characterize air pollution in the last few years. This study involves the usage of this technology for the first time to assess PM2.5 pollution at four cities on the U.S.–Mexico border. These cities in the Lower Rio Grande Valley Region of South Texas are Brownsville, Edinburg, Weslaco, and Port Isabel. A year-long sampling campaign was undertaken from 1 March 2021 to 31 March 2022. TSI BlueSky™ Air Quality Monitors were deployed concurrently at 11 different locations in these four cities. Twenty-four-hour PM2.5 concentrations from these sensors were then compared with ambient …


Electrospun Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate)/Olive Leaf Extract Fiber Mesh As Prospective Bio-Based Scaffold For Wound Healing, Jose Gustavo De La Ossa, Serena Danti, Jasmine Esposito Salsano, Bahareh Azimi, Veronika Tempesti, Niccoletta Barbani, Maria Digiacomo, Marco Macchia, Mohammed Jasim Uddin, Caterina Cristallini Sep 2022

Electrospun Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate)/Olive Leaf Extract Fiber Mesh As Prospective Bio-Based Scaffold For Wound Healing, Jose Gustavo De La Ossa, Serena Danti, Jasmine Esposito Salsano, Bahareh Azimi, Veronika Tempesti, Niccoletta Barbani, Maria Digiacomo, Marco Macchia, Mohammed Jasim Uddin, Caterina Cristallini

Chemistry Faculty Publications and Presentations

Polyhydroxyalkanoates (PHAs) are a family of biopolyesters synthesized by various microorganisms. Due to their biocompatibility and biodegradation, PHAs have been proposed for biomedical applications, including tissue engineering scaffolds. Olive leaf extract (OLE) can be obtained from agri-food biowaste and is a source of polyphenols with remarkable antioxidant properties. This study aimed at incorporating OLE inside poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) fibers via electrospinning to obtain bioactive bio-based blends that are useful in wound healing. PHBHV/OLE electrospun fibers with a size of 1.29 ± 0.34 µm were obtained. Fourier transform infrared chemical analysis showed a uniform surface distribution of hydrophilic -OH groups, confirming the …


Search For Gravitational Waves From Scorpius X-1 With A Hidden Markov Model In O3 Ligo Data, R. Abbott, H. Abe, F. Acernese, K. Ackley, N. Adhikari, M. G. Benjamin, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang Sep 2022

Search For Gravitational Waves From Scorpius X-1 With A Hidden Markov Model In O3 Ligo Data, R. Abbott, H. Abe, F. Acernese, K. Ackley, N. Adhikari, M. G. Benjamin, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

Results are presented for a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to allow for spin wandering. This search improves on previous HMM-based searches of Laser Interferometer Gravitational-Wave Observatory data by including the orbital period in the search template grid, and by analyzing data from the latest (third) observing run. In the frequency range searched, from 60 to 500 Hz, we find no evidence of gravitational radiation. This is the most sensitive search for Scorpius X-1 using a HMM to date. For the most sensitive subband, starting at …


Uav-Assisted Sensor Data Dissemination In Mmwave Vehicular Networks Based On Network Coding, Shidong Huang, Chuanhe Huang, Dongfang Wu, Yabo Yin, M. Wasim Abbas Ashraf, Bin Fu Sep 2022

Uav-Assisted Sensor Data Dissemination In Mmwave Vehicular Networks Based On Network Coding, Shidong Huang, Chuanhe Huang, Dongfang Wu, Yabo Yin, M. Wasim Abbas Ashraf, Bin Fu

Computer Science Faculty Publications and Presentations

Due to good maneuverability, UAVs and vehicles are often used for environment perception in smart cities. In order to improve the efficiency of sensor data sharing in UAV-assisted mmWave vehicular network (VN), this paper proposes a sensor data sharing method based on blockage effect identification and network coding. The concurrent sending vehicles selection method is proposed based on the availability of mmWave link, the number of target vehicles of sensor data packet, the distance between a sensor data packet and target vehicle, the number of concurrent sending vehicles, and the waiting time of sensor data packet. The construction method of …


Ligand-Based Virtual Screening And Molecular Docking Of Benzimidazoles As Potential Inhibitors Of Triosephosphate Isomerase Identified New Trypanocidal Agents, Lenci K. Vazquez-Jimenez, Alfredo Juarez-Saldivar, Rogelio Gomez-Escobedo, Timoteo Delgado-Maldonado, Domingo Mendez-Alvarez, Isidro Palos, Debasish Bandyopadhyay, Carlos Gaona-Lopez, Eyra Ortiz-Perez, Benjamin Nogueda-Torres, Esther Ramirez-Moreno, Gildardo Rivera Sep 2022

Ligand-Based Virtual Screening And Molecular Docking Of Benzimidazoles As Potential Inhibitors Of Triosephosphate Isomerase Identified New Trypanocidal Agents, Lenci K. Vazquez-Jimenez, Alfredo Juarez-Saldivar, Rogelio Gomez-Escobedo, Timoteo Delgado-Maldonado, Domingo Mendez-Alvarez, Isidro Palos, Debasish Bandyopadhyay, Carlos Gaona-Lopez, Eyra Ortiz-Perez, Benjamin Nogueda-Torres, Esther Ramirez-Moreno, Gildardo Rivera

Chemistry Faculty Publications and Presentations

Trypanosoma cruzi (T. cruzi) is a parasite that affects humans and other mammals. T. cruzi depends on glycolysis as a source of adenosine triphosphate (ATP) supply, and triosephosphate isomerase (TIM) plays a key role in this metabolic pathway. This enzyme is an attractive target for the design of new trypanocidal drugs. In this study, a ligand-based virtual screening (LBVS) from the ZINC15 database using benzimidazole as a scaffold was accomplished. Later, a molecular docking on the interface of T. cruzi TIM (TcTIM) was performed and the compounds were grouped by interaction profiles. Subsequently, a selection of compounds was made based …


Eigen’S Paradox And The Quasispecies Model In A Non-Archimedean Framework, Wilson A. Zuniga-Galindo Sep 2022

Eigen’S Paradox And The Quasispecies Model In A Non-Archimedean Framework, Wilson A. Zuniga-Galindo

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this article we present a new p -adic generalization of the Eigen–Schuster model where the genomes (sequences) are represented by words written in the alphabet { 0 , 1 , … , p − 1 } , where p is a prime number, with a time variable length. The time evolution of the concentration of a given sequence is controlled by a p -adic evolution equation. The long term behavior of the concentration of a sequence depends on a fitness function f , a mutation measure Q , and an initial concentration distribution. The new model provides essentially two …


Coupled Surface Plasmon–Phonon Polariton Nanocavity Arrays For Enhanced Mid-Infrared Absorption, Satya R. Kachiraju, Ivan Nekrashevich, Imtiaz Ahmad, Hira Farooq, Long Chang, Sangsik Kim, Myoung-Hwan Kim Sep 2022

Coupled Surface Plasmon–Phonon Polariton Nanocavity Arrays For Enhanced Mid-Infrared Absorption, Satya R. Kachiraju, Ivan Nekrashevich, Imtiaz Ahmad, Hira Farooq, Long Chang, Sangsik Kim, Myoung-Hwan Kim

Physics and Astronomy Faculty Publications and Presentations

Resonant optical cavities are essential components in mid-infrared applications. However, typical film-type cavities require multilayer stacks with a micronthick spacer due to mid-infrared wavelengths, and their performance is limited by narrow frequency tunability and angular sensitivity. We propose and experimentally demonstrate the subwavelength-scale (≈𝜆0/150) resonant nanocavity arrays that enhance the absorption spectrum of the device in the mid-infrared (10–12 microns) via excitation of coupled surface plasmon–phonon polaritons. The proposed metal–insulator–polar dielectric (gold–silicon–silicon carbide) structure supports a guided mode of the coupled surface polaritons in the lateral direction while vertically confining the mid-infrared wave


Elucidating Thermochemical Pretreatment Effectiveness Of Different Particle-Size Switchgrass For Cellulosic Ethanol Production, Jikai Zhao, Yang Yang, Meng Zhang, Charles W. Rice, Donghai Wang Sep 2022

Elucidating Thermochemical Pretreatment Effectiveness Of Different Particle-Size Switchgrass For Cellulosic Ethanol Production, Jikai Zhao, Yang Yang, Meng Zhang, Charles W. Rice, Donghai Wang

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

Effects of switchgrass particle sizes (pretreatments were investigated. As particle size increased, glucan, xylan, and lignin contents in raw switchgrass augmented from 30.32% to 32.02%, 18.44% to 19.03%, and 14.78% to 15.33%, respectively. Glucan and xylan (58.54–60.94% and 18.55–20.01%) contents in NaOH pretreated switchgrass and their recoveries (91.95–94.69% and 47.91–52.31%) increased. The highest glucan content (55.76%) and recovery (79.72%) in H2SO4 pretreated switchgrass were reached by middle particle size. The lowest (59.39% for H2SO4 and 58.99% for NaOH) and highest (65.23% for H2SO4 and 66.15% for NaOH) CrI values were obtained from middle and small particle sizes, respectively. …


Production Of Distilled Spirits Using Grain Sorghum Through Liquid Fermentation, Thomas Weiss, Jikai Zhao, Ruijia Hu, Meicen Liu, Yonghui Li, Yi Zheng, Gordon Smith, Donghai Wang Sep 2022

Production Of Distilled Spirits Using Grain Sorghum Through Liquid Fermentation, Thomas Weiss, Jikai Zhao, Ruijia Hu, Meicen Liu, Yonghui Li, Yi Zheng, Gordon Smith, Donghai Wang

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

The objectives of this research were to investigate the fermentation performance of US sorghum varieties for the production of distilled spirits as well as their associated coproducts and to study the formation of volatile compounds that are related to the flavor quality of the spirits. Three US sorghum varieties (red, white, and waxy sorghums) and four yeast strains (DADY, Ethanol Red, GR-2, and 71B) were used for distilled spirit production. Both sorghum variety and type of yeast strains had effects on alcohol concentration and alcohol yield. The alcohol concentration varied from 10.26 to 11.34% (v/v) while alcohol yield varied from …


Low Soil Nitrogen And Moisture Limit The Expansion Of The Invasive Grass, Megathyrsus Maximus (Guinea Grass) In Semi-Arid Soils, E. Penelope Holland, Vanessa Thomas, Pushpa G. Soti Sep 2022

Low Soil Nitrogen And Moisture Limit The Expansion Of The Invasive Grass, Megathyrsus Maximus (Guinea Grass) In Semi-Arid Soils, E. Penelope Holland, Vanessa Thomas, Pushpa G. Soti

Biology Faculty Publications and Presentations

The goal of this study was to predict the range expansion potential of an invasive forage grass, Guinea grass (Megathyrsus maximus). We collected rhizosphere soil samples of M. maximus and coexisting species from 150 different locations and analysed them for soil properties. We estimated the probability of M. maximus presence as a function of soil moisture, organic matter, pH, salinity, total N, and CN ratio using logistic regression. Presence of M. maximus was associated with higher soil moisture, higher organic matter, pH, and nitrogen, but lower salinity and CN ratio. Soil nitrogen and moisture …


Why New Zealand’S Indigenous Reconciliation Process Has Failed To Empower Māori Fishers: Distributional, Procedural, And Recognition-Based Injustices, Hekia Bodwitch, Andrew M. Song, Owen Temby, John Reid, Megan Bailey, Gordon M. Hickey Sep 2022

Why New Zealand’S Indigenous Reconciliation Process Has Failed To Empower Māori Fishers: Distributional, Procedural, And Recognition-Based Injustices, Hekia Bodwitch, Andrew M. Song, Owen Temby, John Reid, Megan Bailey, Gordon M. Hickey

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

How is it that the New Zealand government’s process for re-establishing Indigenous fishing rights has failed to deliver thriving Māori fisheries? This paper examines why, at Te Waihora, a coastal lake, and site of one of the nation’s longest running and best-funded state-Māori co-governance agreements, Māori fishers have been unable to use their rights to support their fishery. As of 2018, the lake’s culturally and ecologically significant eel population was no longer commercially viable, a decline fishers have attributed to rampant dairy industry expansion upstream. Drawing on environmental justice literatures, we deploy a multi-dimensional framework to identify factors shaping possibilities …


Irrigation Decisions In Response To Groundwater Salinity In Kansas, Juhee Lee, Nathan P. Hendricks Sep 2022

Irrigation Decisions In Response To Groundwater Salinity In Kansas, Juhee Lee, Nathan P. Hendricks

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

Understanding the interaction between groundwater salinity and irrigation decision making has important implications for groundwater management. Econometrics models were estimated using observed farmer behavior in response to different groundwater salinity levels in a region of Kansas. Estimation results demonstrate that farmers in the face of groundwater salinity change their irrigation decisions on irrigated acreage (i.e., extensive margin), crop choice (i.e., indirect intensive margin), and water application depth (i.e., direct intensive margin). The empirical results indicate an overall decrease in water use due to higher salinity, primarily through a decrease at the extensive margin.


Definite Condition Of The Evolutionary (P)Over-Right-Arrow(X)-Laplacian Equation, Huashui Zhan, Zhaosheng Feng Sep 2022

Definite Condition Of The Evolutionary (P)Over-Right-Arrow(X)-Laplacian Equation, Huashui Zhan, Zhaosheng Feng

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

For the nonlinear degenerate parabolic equations, how to find an appropriate boundary value condition to ensure the well-posedness of weak solution has been an interesting and challenging problem. In this paper, we develop the general characteristic function method to study the stability of weak solutions based on a partial boundary value condition.


Fine Particulate Matter Concentrations During Independence Day Fireworks Display In The Lower Rio Grande Valley Region, South Texas, Usa, Esmeralda Mendez, Owen Temby, Dawid K. Wladyka, Katarzyna Sepielak, Amit U. Raysoni Sep 2022

Fine Particulate Matter Concentrations During Independence Day Fireworks Display In The Lower Rio Grande Valley Region, South Texas, Usa, Esmeralda Mendez, Owen Temby, Dawid K. Wladyka, Katarzyna Sepielak, Amit U. Raysoni

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

Fireworks are typically discharged as a mark of celebration and joy in many societies spanning various cultures. In the United States of America, 4th July is celebrated as the Independence Day when the nation overthrew the British colonial yoke in 1776. While this day instills a sense of patriotism in every American’s heart, it is also a major PM2.5 air pollution concern. This study is first of its type in the Lower Rio Grande Valley (RGV) Region of South Texas, USA, that characterizes fine particulate matter pollution. Using a low-cost sensor (TSI BlueSky Air Quality Monitor), real-time PM2.5 measurements were …


Darboux Transformation And Solitonic Solution To The Coupled Complex Short Pulse Equation, Bao-Feng Feng, Liming Ling Sep 2022

Darboux Transformation And Solitonic Solution To The Coupled Complex Short Pulse Equation, Bao-Feng Feng, Liming Ling

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The Darboux transformation (DT) for the coupled complex short pulse (CCSP) equation is constructed through the loop group method. The DT is then utilized to construct various exact solutions including bright soliton, dark-soliton, breather and rogue wave solutions to the CCSP equation. In case of vanishing boundary condition (VBC), we perform the inverse scattering analysis to understand the soliton solution better. Breather and rogue wave solutions are constructed in case of non-vanishing boundary condition (NVBC). Moreover, we conduct a modulational instability (MI) analysis based on the method of squared eigenfunctions, whose result confirms the condition for the existence of rogue …


Excitation-Dependent Photoluminescence Of Bazro3:Eu3+ Crystals, Santosh K. Gupta, Hisham Abdou, Carlo U. Segre, Yuanbing Mao Aug 2022

Excitation-Dependent Photoluminescence Of Bazro3:Eu3+ Crystals, Santosh K. Gupta, Hisham Abdou, Carlo U. Segre, Yuanbing Mao

Chemistry Faculty Publications and Presentations

The elucidation of local structure, excitation-dependent spectroscopy, and defect engineering in lanthanide ion-doped phosphors was a focal point of research. In this work, we have studied Eu3+-doped BaZrO3 (BZOE) submicron crystals that were synthesized by a molten salt method. The BZOE crystals show orange–red emission tunability under the host and dopant excitations at 279 nm and 395 nm, respectively, and the difference is determined in terms of the asymmetry ratio, Stark splitting, and intensity of the uncommon 5D07F0 transition. These distinct spectral features remain unaltered under different excitations for the BZOE …


Upcycling Mask Waste To Carbon Capture Sorbents: A Combined Experimental And Computational Study, Mark Robertson, Alejandro Guillen Obando, Bianca Nunez, Haoyuan Chen, Zhe Qiang Aug 2022

Upcycling Mask Waste To Carbon Capture Sorbents: A Combined Experimental And Computational Study, Mark Robertson, Alejandro Guillen Obando, Bianca Nunez, Haoyuan Chen, Zhe Qiang

Chemistry Faculty Publications and Presentations

Massive plastic pollution and grand scale emission of CO2 into the atmosphere represent two major and deeply connected societal challenges, which can have adverse impacts on climate, human health, and marine ecosystems. In particular, the COVID-19 pandemic led to substantially increased production, use, and discarding of disposable masks, a problem that requires urgent and effective technological solutions to mitigate their negative environmental impacts. Furthermore, over the years significant research efforts have sought to address the challenges of plastic waste and CO2 emission, such as development of chemical upcycling methods and low-cost CO2 capture sorbents at scale, respectively. In this work, …