Digital Commons Network^™

Investigation Of Constant Volume And Constant Flux Initial Conditions On Bidensity Particle-Laden Slurries On An Incline, Dominic Diaz, Jessica Bojorque, Joshua Crasto, Margaret Koulikov, Tameez Lati, Aviva Prins, Andrew Shapiro, Clover Ye, David Arnold, Michael R. Lindstrom

School of Mathematical & Statistical Sciences Faculty Publications

Particle-laden slurries are pervasive in both natural and industrial settings, whenever particles are suspended or transported in a fluid. Previous literature has investigated the case of a single species of negatively buoyant particles suspended in a viscous fluid. On an incline, three distinct regimes emerge depending on the particle concentration and inclination angle: settled (where particles settle and there is a pure fluid front), well-mixed (where particle concentration is constant throughout), and ridged (where a particle-rich ridge leads the flow). Recently, the same three regimes were also found for constant volume two species bidensity slurries. We extend the literature on …

Viability Of Wetland Crops For Use In Treatment Wetlands: Nitrogen Removal From Water And Production Of Food, Andrew Denson Corder

Theses and Dissertations

Treatment wetlands are used to treat wastewater from a variety of sources, but their functionality depends on the macrophytes present therein. To better understand the viability of wetland macrophytes both as sources of food and as agents of nitrogen removal from wastewater, this study quantified plant growth, food production, and nitrogen removal capacity of three common wetland crops as well as three locally dominant graminoid species in a variety of relevant ecological contexts. All six plant species and a control were grown over a ten-week period in three related experiments: (1) under three moisture regimes, (2) with or without competition …

A Landscape-Scaled And Community Ecology Approach To Wildlife Corridor Design In South Texas, James A. Stilley

Theses and Dissertations

A formidable challenge in landscape ecology is developing a sound resolution to mitigate the impacts of habitat fragmentation and restore connectivity to a degraded landscape. The problem is worldwide landscapes are becoming primarily anthropogenic and areas set aside for wildlife are small and isolated. Researchers’ have developed the concept of the wildlife corridor to mediate this situation but a proper methodology to implement this concept is still in its infancy. This study aims to uncover a quantitative and repeatable wildlife corridor design methodology based on the least cost analysis strategy with both a singular focal taxa approach and a comprehensive …

Detecting Phone-Related Pedestrian Behavior Using A Two-Branch Convolutional Neural Network, Humberto Saenz

Theses and Dissertations

With the wide use of smart phones, distraction has become a major safety concern to roadway users. The distracted phone-use behaviors among pedestrians, like Texting, Game Playing and Phone Calls, have caused increasing fatalities and serious injuries. With the increasing usage of driver monitor systems on intelligent vehicles, distracted driver behaviors can be efficiently detected and warned. However, the research of phone-related distracted behavior by pedestrians has not been systemically studied. It is desired to improve both the driving and pedestrian safety by automatically discovering the phone-related pedestrian distracted behaviors. In this thesis, we propose a new computer vision-based method …

Elementary Statistics Instructors' Uptake Of The Teaching Practices Recommended By The American Statistical Association, Marisol Sanchez Cortez

Theses and Dissertations

Previous studies point out there has been a wide gap, in the teaching of mathematics, between the practices recommended in the credential programs and the practices teachers actually do. The purpose of this study is to explore how consistent the teaching practices of introductory statistics instructors are to the recommendations endorsed by the American Statistical Association, to understand what their attitudes to the gap are, and to identify the factors that prevent the instructors from implementing the recommended practices. Data were collected from nine statistics instructors at a state university through survey, classroom observations, and interviews. Findings indicate that the …

Kcrs: A Blockchain-Based Key Compromise Resilient Signature System, Lei Xu, Lin Chen, Zhimin Gao, Xinxin Fan, Kimberly Doan, Shouhuai Xu, Weidong Shi

Computer Science Faculty Publications

Digital signatures are widely used to assure authenticity and integrity of messages (including blockchain transactions). This assurance is based on assumption that the private signing key is kept secret, which may be exposed or compromised without being detected in the real world. Many schemes have been proposed to mitigate this problem, but most schemes are not compatible with widely used digital signature standards and do not help detect private key exposures. In this paper, we propose a Key Compromise Resilient Signature (KCRS) system, which leverages blockchain to detect key compromises and mitigate the consequences. Our solution keeps a log of …

The Increase Of Hiv-1 Infection, Neurocognitive Impairment, And Type 2 Diabetes In The Rio Grande Valley, Roberto De La Garza, Hansapani Rodrigo, Francisco Fernandez, Upal Roy

Health & Biomedical Sciences Faculty Publications

The Human Immunodeficiency Virus (HIV-1) infection remains a persistent predicament for the State of Texas, ranking seventh among the most documented HIV cases in the United States. In this regard, the Rio Grande Valley (RGV) in South Texas is considered as one of the least investigated areas of the state with respect to HIV infection and HIV associated comorbidities. Considering the 115% increase in average HIV incidence rates per 100,000 within the RGV from 2007-2015, it is worth characterizing this population with respect to their HIV-1 infection, HIV-1 Associated Neurocognitive Disorders (HAND), and the association of treatment with combined antiretroviral …

High-Order Rogue Waves Of A Long-Wave–Short-Wave Model Of Newell Type, Jungchao Chen, Liangyuan Chen, Bao-Feng Feng, Ken-Ichi Maruno

School of Mathematical & Statistical Sciences Faculty Publications

The long-wave–short-wave (LWSW) model of Newell type is an integrable model describing the interaction between the gravity wave (long wave) and the capillary wave (short wave) for the surface wave of deep water under certain resonance conditions. In the present paper, we are concerned with rogue-wave solutions to the LWSW model of Newell type. By combining the Hirota’s bilinear method and the KP hierarchy reduction, we construct its general rational solution expressed by the determinant. It is found that the fundamental rogue wave for the short wave can be classified into three different patterns: bright, intermediate, and dark states, whereas …

Insights To The Genetic Structure Of Calanus Helgolandicus (Calanoida: Copepoda) From Deep-Sea Specimens In The Balearic Sea, Diego F. Figueroa, Joan E. Cartes, Nicole J. Figueroa

School of Earth, Environmental, & Marine Sciences Faculty Publications

Calanus helgolandicus is widely distributed across the northeast Atlantic and Mediterranean, and also found in the Black Sea where it is referred to as Calanus euxinus. Previous genetic studies do not include deep-water specimens despite high abundances at bathypelagic and mesopelagic depths. Our objective is to compare the genetic structure of C. heloglandicus from the deep Balearic Sea to that of coastal populations in the Northeastern Atlantic Ocean, the Adriatic Sea, and the Black Sea defined from previous research. We use a portion of the mitochondrial gene cytochrome oxidase I from 41 individuals of C. helgolandicus collected at 2170 m …

Mitogenomic Phylogenetic Analyses Of Leptogorgia Virgulata And Leptogorgia Hebes (Anthozoa: Octocorallia) From The Gulf Of Mexico Provides Insight On Gorgoniidae Divergence Between Pacific And Atlantic Lineages, Samantha Silvestri, Diego F. Figueroa, David Hicks, Nicole J. Figueroa

School of Earth, Environmental, & Marine Sciences Faculty Publications

The use of genetics in recent years has brought to light the need to reevaluate the classification of many gorgonian octocorals. This study focuses on two Leptogorgia species—Leptogorgia virgulata and Leptogorgia hebes—from the northwestern Gulf of Mexico (GOM). We target complete mitochondrial genomes and mtMutS sequences, and integrate this data with previous genetic research of gorgonian corals to resolve phylogenetic relationships and estimate divergence times. This study contributes the first complete mitochondrial genomes for L. ptogorgia virgulata and L. hebes. Our resulting phylogenies stress the need to redefine the taxonomy of the genus Leptogorgia in its entirety. The fossil-calibrated divergence …

Tests Of General Relativity With The Binary Black Hole Signals From The Ligo-Virgo Catalog Gwtc-1, B. P. Abbott, S. Mukherjee

Physics & Astronomy Faculty Publications

The detection of gravitational waves by Advanced LIGO and Advanced Virgo provides an opportunity to test general relativity in a regime that is inaccessible to traditional astronomical observations and laboratory tests. We present four tests of the consistency of the data with binary black hole gravitational waveforms predicted by general relativity. One test subtracts the best-fit waveform from the data and checks the consistency of the residual with detector noise. The second test checks the consistency of the low- and high-frequency parts of the observed signals. The third test checks that phenomenological deviations introduced in the waveform model (including in …

The Complete Mitochondrial Genome Of Tanacetipathes Thamnea Warner, 1981 (Antipatharia: Myriopathidae), Diego F. Figueroa, David Hicks, Nicole J. Figueroa

School of Earth, Environmental, & Marine Sciences Faculty Publications

Specimens of the black coral Tanacetipathes thamnea were collected from the Northwestern Gulf of Mexico. The complete mitochondrial genome of one of these specimens was obtained from genomic DNA by next-generation sequencing technology on the Illumina HiSeq 2500. Only three species of black corals have a completely sequenced mitochondrial genome. These were used to reconstruct the phylogeny for the order Antipatharia. The mitochondrial genome of T. thamnea is 17,712 base pairs and contains 13 protein-coding genes, 2 ribosomal RNAs, and 2 transfer RNAs in the following order: 16s RNA, COX3, COX1 (with intron), ND4L, COX2, ND4, …

Novel Silica Filled Deep Eutectic Solvent Based Nanofluids For Energy Transportation, Changhui Liu, Hui Fang, Xinjian Liu, Ben Xu, Zhonghao Rao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Liquid range of nanofluids is a crucial parameter as it intensively determines their application temperature scope. Meanwhile, improved thermal conductivity and stability are of great significances and comprise the main fundamental research topics of nanofluids. In this work, 2- butoxy-3,4-dihydropyran (DP), produced from a convenient one-pot three-component reaction in water, was employed as dual lipophilic brusher and metal nanoparticle anchor. It was found that DP was able to enhance the dispersing ability and thermal conductivity of SiO2 nanoparticle filled deep eutectic solvent (DES) based nanofluids simultaneously. The key to the success of this protocol mainly relies on the electrophilic property …

Non-Invasive Methods For Measuring And Monitoring Stress Physiology In Imperiled Amphibians, Edward J. Narayan, Zachery R. Forsburg, Drew R. Davis, Caitlin R. Gabor

School of Earth, Environmental, & Marine Sciences Faculty Publications

Global climate change is negatively impacting global biodiversity and ectothermic vertebrates, with amphibians being the most imperiled vertebrate taxa. Increased mean global atmospheric temperatures, high rates of habitat degradation, and exposure to infectious diseases, such as chytridiomycosis, have contributed to population declines and extinctions of rare and endangered amphibian species. Field-based monitoring of physiological endocrine traits can help determine the sub-lethal effects of environmental stressors and provide early alerts when populations are chronically stressed. Recent advances in amphibian stress endocrinology include the development and use of non-invasive methods to quantify the glucocorticoid, or stress biomarker, corticosterone. Non-invasive methods, such as …

Water‐Borne And Plasma Corticosterone Are Not Correlated In Spotted Salamanders, Alice R. Millikin, Sarah K. Woodley, Drew R. Davis, Ignacio T. Moore, James T. Anderson

School of Earth, Environmental, & Marine Sciences Faculty Publications

Water‐borne hormone measurement is a noninvasive method suitable for amphibians of all sizes that are otherwise difficult to sample. For this method, containment‐water is assayed for hormones released by the animal. Originally developed in fish, the method has expanded to amphibians, but requires additional species‐specific validations. We wanted to determine physiological relevance of water‐borne corticosterone in spotted salamanders (Ambystoma maculatum) by comparing concentrations to those taken using established corticosterone sampling methods, such as plasma. Using a mixture of field and laboratory studies, we compared water‐borne corticosterone levels to other traditional methods of sampling corticosterone for spotted salamander larvae, metamorphs, and …

Sub-Optimal Tracking In Switched Systems With Controlled Subsystems And Fixed-Mode Sequence Using Approximate Dynamic Programming, Tohid Sardarmehni, Xingyong Song

Mechanical Engineering Faculty Publications

Optimal tracking in switched systems with controlled subsystem and Discrete-time (DT) dynamics is investigated. A feedback control policy is generated such that a) the system tracks the desired reference signal, and b) the optimal switching time instants are sought. For finding the optimal solution, approximate dynamic programming is used. Simulation results are provided to illustrate the effectiveness of the solution.

Investigations Of Aerobic Methane Oxidation In Two Marine Seep Environments: Part 1—Chemical Kinetics, Eric W. Chan, Allan M. Shiller, Dongjoo J. Joung, Eleanor C. Arrington, David L. Valentine, Molly C. Redmond, John A. Breier, Scott A. Socolofsky, John D. Kessler

School of Earth, Environmental, & Marine Sciences Faculty Publications

Microbial aerobic oxidation is known to be a significant sink of marine methane (CH4), contributing to the relatively minor atmospheric release of this greenhouse gas over vast stretches of the ocean. However, the chemical kinetics of aerobic CH4 oxidation are not well established, making it difficult to predict and assess the extent that CH4 is oxidized in seawater following seafloor release. Here we investigate the kinetics of aerobic CH4 oxidation using mesocosm incubations of fresh seawater samples collected from seep fields in Hudson Canyon, U.S. Atlantic Margin and MC118, Gulf of Mexico to gain a fundamental chemical understanding of this …

Realistic Sensitivity Curves For Pulsar Timing Arrays, ‪Jeffrey S. Hazboun, Joseph D. Romano, Tristan L. Smith

Physics & Astronomy Faculty Publications

We construct realistic sensitivity curves for pulsar timing array searches for gravitational waves, incorporating both red and white noise contributions to individual pulsar noise spectra, and the effect of fitting to a pulsar timing model. We demonstrate the method on both simulated pulsars and a realistic array consisting of a subset of NANOGrav pulsars used in recent analyses. A comparison between the results presented here and measured upper limit curves from actual analyses shows agreement to tens of percent. The resulting sensitivity curves can be used to assess the detectability of predicted gravitational-wave signals in the nanohertz frequency band in …

Magnetic Field Effect In The Fine-Structure Constant And Electron Dynamical Mass, Efrain J. Ferrer, A. Sanchez

Physics & Astronomy Faculty Publications

We investigate the effect of an applied constant and uniform magnetic field in the fine-structure constant of massive and massless QED. In massive QED, it is shown that a strong magnetic field removes the so called Landau pole and that the fine-structure constant becomes anisotropic having different values along and transverse to the field direction. Contrary to other results in the literature, we find that the anisotropic fine-structure constant always decreases with the field. We also study the effect of the running of the coupling constant with the magnetic field on the electron mass. We find that in both cases …

Investigations Of Aerobic Methane Oxidation In Two Marine Seep Environments: Part 2—Isotopic Kinetics, Eric W. Chan, Allan M. Shiller, Dongjoo J. Joung, Eleanor C. Arrington, David L. Valentine, Molly C. Redmond, John A. Breier, Scott A. Socolofsky, John D. Kessler

School of Earth, Environmental, & Marine Sciences Faculty Publications

During aerobic oxidation of methane (CH4) in seawater, a process which mitigates atmospheric emissions, the 12C‐isotopologue reacts with a slightly greater rate constant than the 13C‐isotopologue, leaving the residual CH4 isotopically fractionated. Prior studies have attempted to exploit this systematic isotopic fractionation from methane oxidation to quantify the extent that a CH4 pool has been oxidized in seawater. However, cultivation‐based studies have suggested that isotopic fractionation fundamentally changes as a microbial population blooms in response to an influx of reactive substrates. Using a systematic mesocosm incubation study with recently collected seawater, here we investigate the fundamental isotopic kinetics of aerobic …

Overcoming The Shadow Of Expertise: How Humility And Learning Goal Orientation Help Knowledge Leaders Become More Flexible, Mai P. Trinh

Management Faculty Publications

Although experts are valuable assets to organizations, they suffer from the curse of knowledge and cognitive entrenchment, which prevents them from being able to adapt to changing situational demands. In this study, I propose that experts’ performance goal orientation resulting from pressures to perform contributes to their flexibility, but this mechanism can be moderated by learning goal orientation and humility. Data from a small sample of healthcare professionals suggested that performance goal orientation partially explained the mechanism of why experts may be inflexible. Humility, both as self-report and other-report measures, was found to be the most consistent moderator of this …

The Rider (2019-11-04), Victor G. Ramirez

The Rider Archives

Vol.5 No.11

Experimental Demonstration Of Deterministic Chaos In A Waste Oil Biodiesel Semi-Industrial Furnace Combustion System, Shengyang Gao, Fashe Li, Qintai Xiao, Jianxin Xu, Huage Wang, Hua Wang

School of Mathematical & Statistical Sciences Faculty Publications

In this paper, the nonlinear dynamic characteristics of the oxygen-enriched combustion of waste oil biodiesel in semi-industrial furnaces were tested by the power spectrum, phase space reconstruction, the largest Lyapunov exponents, and the 0-1 test method. To express the influences of the system parameters, experiments were carried out under different oxygen content conditions (21%, 25%, 28%, 31%, and 33%). Higher oxygen enrichment degrees contribute to finer combustion sufficiency, which produces flames with high luminance. Flame luminance and temperature can be represented by different gray scale values of flame images. The chaotic characteristics of gray scale time series under different oxygen …

Increasing Impacts Of Extreme Droughts On Vegetation Productivity Under Climate Change, Chonggang Xu, Nate G. Mcdowell, Rosie A. Fisher, Liang Wei, Sanna Sevanto, Bradley O. Christoffersen, Engsheng Weng, Richard S. Middleton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Terrestrial gross primary production (GPP) is the basis of vegetation growth and food production globally1 and plays a critical role in regulating atmospheric CO2 through its impact on ecosystem carbon balance. Even though higher CO2 concentrations in future decades can increase GPP2, low soil water availability, heat stress and disturbances associated with droughts could reduce the benefits of such CO2 fertilization. Here we analysed outputs of 13 Earth system models to show an increasingly stronger impact on GPP by extreme droughts than by mild and moderate droughts over the twenty-first century. Due to a dramatic increase in …

Trust And Influence In The Gulf Of Mexico’S Fishery Public Management Network, Anthony Lima, Dongkyu Kim, Andrew M. Song, Gordon M. Hickey, Owen Temby

School of Earth, Environmental, & Marine Sciences Faculty Publications

Sustainable fishery management is a complex multi-sectoral challenge requiring substantial interagency coordination, collaboration, and knowledge sharing. While scholars of public management network theory and natural resource management have identified trust as one of the key ideational network properties that facilitates such interaction, relatively few studies have operationalized and measured the multiple dimensions of trust and their influence on collaboration. This article presents the results of an exploratory study examining the Gulf of Mexico fishery management network comprised of more than 30 stakeholder organizations. Using an empirically validated survey instrument, the distribution of four types of trust, three gradations of influence, …

Remote Sensing Of The Terrestrial Carbon Cycle: A Review Of Advances Over 50 Years, Jingfeng Xiao, Frederic Chevallier, Cecile Gomez, Luis Guanter, Jeffrey A. Hicke, Alfredo R. Huete, Kazuhito Ichii, Wenjian Ni, Yong Pang, Abdullah Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

Highlights

• We review 50 years of history and advances in remote sensing of C fluxes and stocks

• We present an overview of terrestrial C cycle, remote sensing, and key milestones

• We review remote sensing platforms/sensors, data, methods, findings, and challenges

• We also discuss the uncertainty and validation of the C flux and stock estimates

• A forward-looking perspective and insights for future research are provided

Abstract

Quantifying ecosystem carbon fluxes and stocks is essential for better understanding the global carbon cycle and improving projections of the carbon-climate feedbacks. Remote sensing has played a vital role in this endeavor during the last …

Diabetes And Its Effect On Abdominal Aortic Aneurysm Growth Rate In Hispanic Patients, Monica Betancourt-Garcia, Kristina Vatcheva, Amrit Thakur, Prateek Gupta, Eugene Postevka, Ricardo Martinez, R. Armour Forse

School of Mathematical & Statistical Sciences Faculty Publications

Background

The growth rate of abdominal aortic aneurysms (AAA) can vary depending on age, baseline diameter, blood pressure, race, and history of smoking. Paradoxically, previous studies show evidence of a protective effect of diabetes on the rate of AAA expansion despite its well-established role in the morbidity and mortality of cardiovascular disease. This study aims to investigate the impact diabetes plays on AAA growth within a Hispanic population.

Methods

Data were collected from patients who were predominantly Mexican-American at a single hospital site. Baseline and follow-up measures for AAA diameter were obtained from serial imaging studies. Demographics, medical history, the …

The Aluthge Transform Of Unilateral Weighted Shifts And The Square Root Problem For Finitely Atomic Measures, Raul E. Curto, Jasang Yoon

School of Mathematical & Statistical Sciences Faculty Publications

In this paper we consider the following Square Root Problem for measures: Given a positive probability Borel measure μ (supported on an interval [a,b]⊆R+), does there exist a positive Borel measure ν such that μ=ν*ν holds? (Here * denotes the multiplicative convolution, properly defined on R+.) This problem is intimately connected to the subnormality of the Aluthge transform of a unilateral weighted shift. We develop a criterion to test whether a measure μ admits a square root, and we provide a concrete solution for the case of a finitely atomic measure having at most five atoms. In addition, we sharpen …

Search For Gravitational-Wave Signals Associated With Gamma-Ray Bursts During The Second Observing Run Of Advanced Ligo And Advanced Virgo, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang

Physics & Astronomy Faculty Publications

We present the results of targeted searches for gravitational-wave transients associated with gamma-ray bursts during the second observing run of Advanced LIGO and Advanced Virgo, which took place from 2016 November to 2017 August. We have analyzed 98 gamma-ray bursts using an unmodeled search method that searches for generic transient gravitational waves and 42 with a modeled search method that targets compact-binary mergers as progenitors of short gamma-ray bursts. Both methods clearly detect the previously reported binary merger signal GW170817, with p-values of z ≤ 1. We estimate 0.07–1.80 joint detections with Fermi-GBM per year for the 2019–20 …

The Rider (2019-10-28), Victor G. Ramirez

The Rider Archives

Vol.5 No.10