Physical Sciences and Mathematics Commons^™

Experiment And Simulation Platform For Oasis-Desert Symbiotic Relationship (Odp), Yan Li, Xinjun Zheng, Yuguang Wang, Guiqing Xu, Ran Liu

Bulletin of Chinese Academy of Sciences (Chinese Version)

Junggar Basin is a typical arid inland region in the northern temperate zone of the Earth. The surrounding high mountains form runoff, which flows into the basin and develops oasis. Oasis and desert are interdependent. Oasis needs to leach out its naturally accumulated salts through drainage. This drainage provides water and nutrients to desert vegetation. Desert vegetation, in turn, provides an ecological protection for oasis. Hence, oasis and desert have a symbiotic relationship. With excessive exploitation of land and water resources with water-saving technologies, salts cannot be leached out of the oasis region anymore. As a result, the groundwater level …

Development Experience Of International Open Source And Its Enlightenment To Construction Of Open Source Innovation System In China, Yuntao Long, Xiaoming Wang, Rong Gu, Yungang Bao

Bulletin of Chinese Academy of Sciences (Chinese Version)

Open source has become an essential innovation model for global technological progress and the construction of an open source innovation system is an important path for China to achieve self-reliance and self-improvement in science and technology. As an indispensable part of the global software value chain and high-tech industry chain, China needs to improve its open source innovation ecosystem. The paper, based on a systematic review of the related development policies and successful experiences on the open source work in US and Europe, puts forward a series of policy suggestions to solve the practical problems faced by the construction of …

Development And Characterization Of An Underwater Acoustics Laboratory Via In Situ Impedance Boundary Measurements, Cameron Taylor Vongsawad

Theses and Dissertations

Modeling underwater acoustic propagation comes with a variety of challenges due to the need for proper characterization of the environmental conditions. These conditions include ever changing and complex water properties as well as boundary conditions. The BYU underwater acoustics open-air tank test-bed and measurement chain were developed to study underwater acoustic propagation within a controlled environment. It was also developed to provide ways to test and validate ocean models without the high cost associated with obtaining open ocean measurements. However, tank measurements require additional characterization of boundary conditions associated with the walls of the tank which would not be present …

Acute Pediatric Chagas Disease In Antioquia, Colombia: A Geographic Location Of Suspected Oral Transmission, Lídia Gual-Gonzalez, Catalina Aango-Ferreira, Laura Camila Lopera-Restrepo, Omar Cantillo-Barraza, Daniela Velásquez Marín, Natalia Restrepo Bustamante, Omar Triana-Chavez, Melissa Nolan Ph.D., Mph

Faculty Publications

Chagas disease, Trypanosoma cruzi infection, is an insidious cause of heart failure in Latin America. Early diagnosis and treatment are critical to prevent irreversible myocardial damage that progressively accumulates over decades. Several structural barriers account for the less than 1% of cases in Colombia being treated, including poor physician knowledge, especially considering that some regions are considered non-endemic. The two cases reported here represent an emerging epidemiologic scenario associated with pediatric Chagas disease. Both cases are suspected oral transmitted parasitic infection in a geographic region of Colombia (Andean region of Antioquia) where no previous oral transmission of Chagas disease had …

Characterization And Interpretation Of Feldspathic Chromite Assemblages (Fcas) In Four Ordinary Chondrites: An Electron Backscatter Diffraction (Ebsd) Study, Kimberly Louisa Maccini

Dissertations and Theses

Feldspathic Chromite Assemblages (FCAs) are chemically distinctive assemblages rich in Na, Al, and Cr that are found in a variety of chondrites. They consist of concentrations of chromite associated mainly with feldspathic material, either feldspar or the glassy material known as maskelynite. Professor Alan Rubin (2003) has proposed that some FCAs formed by shock melting, but the origin of different types of feldspathic chromite assemblages are unclear and have not been studied with more modern techniques such as Electron Backscatter Electron Diffraction (EBSD).

Here EBSD was used to study FCAs in four metamorphosed ordinary chondrites of different shock stages, including …

Stability And Mechanical Properties Of W1-X Mox B4.2 (X=0.0-1.0) From First Principles, Weiguang Gong, Rui Xu, Xuecheng Shao, Quan Li, Changfeng Chen

Physics & Astronomy Faculty Research

Heavy transition-metal tetraborides (e.g., tungsten tetraboride, molybdenum tetraboride, and molybdenum-doped tungsten tetraboride) exhibit superior mechanical properties, but solving their complex crystal structures has been a long-standing challenge. Recent experimental x-ray and neutron diffraction measurements combined with first-principles structural searches have identified a complex structure model for tungsten tetraboride that contains a boron trimer as an unusual structural unit with a stoichiometry of 1:4.2. In this paper, we expand the study to binary MoB4.2 and ternary W1-xMoxB4.2 (x=0.0-1.0) compounds to assess their thermodynamic stability and mechanical properties using a tailor-designed crystal structure search method in conjunction with first-principles energetic calculations. Our …

Bayesian, Frequentist, And Information Geometry Approaches To Parametric Uncertainty Quantification Of Classical Empirical Interatomic Potentials, Yonatan Kurniawan

Theses and Dissertations

Uncertainty quantification (UQ) is an increasingly important part of materials modeling. In this paper, we consider the problem of quantifying parametric uncertainty in classical empirical interatomic potentials (IPs). Previous work based on local sensitivity analysis using the Fisher Information has shown that IPs are sloppy, i.e., are insensitive to coordinated changes of many parameter combinations. We confirm these results and further explore the non-local statistics in the context of sloppy model analysis using both Bayesian (MCMC) and Frequentist (profile likelihood) methods. We interface these tools with the Knowledgebase of Interatomic Models (OpenKIM) and study three models based on the Lennard-Jones, …

Existence Results For Nonlinear Schrodinger Equations Involving The Fractional (P, Q)-Laplacian And Critical Nonlinearities, Huilin Lv, Shenzhou Zheng, Zhaosheng Feng

School of Mathematical & Statistical Sciences Faculty Publications

In this article, we consider the existence of ground state positive solutions for nonlinear Schrodinger equations of the fractional (p, q)-Laplacian with Rabinowitz potentials defined in R-n,

(-Delta)(p)(s1) u + (-Delta)(q)(s2) q u+ V(epsilon x)(vertical bar u vertical bar(p-2)u+vertical bar u vertical bar(q-2)u) =lambda f(u) + sigma vertical bar u vertical bar q*(-2)(s2)u.

We prove existence by confining different ranges of the parameter lambda under the subcritical or critical nonlinearities caused by sigma = 0 or 1, respectively. In particular, a delicate calculation for the critical growth is provided so as to avoid the failure of a global Palais-Smale condition …

Principal Component Analysis In Paspalum Germplasm Characterization, A. Regitano Neto, L. A. R. Batista

IGC Proceedings (1977-2023)

In a survey, through principal component analyses, for the most representative descriptors to be used in Paspalum germplasm characterization, 16 agronomic traits, 16 reproductive traits and 21 vegetative traits were evaluated in 32 accessions comprising Paspalum plicatulum (19) and Paspalum compressifolium (13) from the institutional germplasm collection. ANOVA for agronomic descriptors showed significant differences among accessions, except for percentage of dry matter in winter (DMW) which was not significant. Principal component analyses allowed reduction of 69%, 69% and 62%, respectively, in the initial number of descriptors, and the election of the most important for agronomic traits: DMYS, DMYW, RGS, CPPW …

Production And Quality Of Paspalum Forage In State Of São Paulo, L. A. R. Batista, A. Regitano Neto, Rodolfo Godoy

IGC Proceedings (1977-2023)

Biomass produced by accessions of 26 species, belonging to 12 botanical groups of the genus Paspalum, collected in the south and central regions of Brazil, were evaluated during the first year of establishment for quantitative characteristics: production of dry biomass (DMY), percentage of dry matter (PDM) and regrowth score and qualitative traits: concentration of neutral detergent fiber (NDF), “in vitro” dry matter digestibility (IVDMD) and crude protein percentage in dry matter (CPPDM) -, in the central area of the state of São Paulo, in a completely randomized block design with two replications. The largest averages of DMY were obtained …

Study Of The Diversity Of Soil Animals Community In The Songnen Plain Grassland Of China, Xiuqin Yin, Tingcheng Zhu

IGC Proceedings (1977-2023)

This paper dealt with the diversity in eight habitat soil animals communities in Songnen plain grassland. The results showed the better habitat condition the higher diversity index of soil animals, and vice-versa. The diversity of soil animals communities correlated positively with soil organic matter, total nitrogen, and negatively with soil pH; there was a poor correlation with soil water content and total soil phosphorus. The diversity of soil animals communities decreased with increasing depth of soil layer and has surface-collection.

Evaluating Varieties Of Alfalfa And Tall Fescue For Tolerance To Over-Grazing By Cattle, Robert F. Spitaleri, Jimmy C. Henning, Charles T. Dougherty, Garry D. Lacefield, B. T. Larson

IGC Proceedings (1977-2023)

Cultivars of alfalfa (Medicago sativa L.) and tall fescue (Festuca arundinacea Schreb.) were seeded in small (1.5 m x 4.6 m) plots and harvested for estimating yield the following spring. Plots were then grazed by cattle continuously for the remainder of the season so as to keep stand heights at 7.5 cm or less. This procedure was repeated for one or two more grazing seasons, depending on stand survival. Stands were visually rated for stand in the fall and spring. Marked differences in grazing tolerance were observed among alfalfa cultivars, following closely the commercial designations as grazing-type or …

The Role Of Cattle Dung In Seed Dispersal Of Major Species In A Zoysia Japonica Pasture In Japan, K. Shimoda, S. Sakanoue

IGC Proceedings (1977-2023)

To evaluate the role of cattle dung in seed dispersal of major species in Zoysia japonica pasture in Japan, we investigated the species composition and density of seeds in cattle dung by means of a germination test. Of 20 major species which had a mean coverage of more than 0.1%, 90% were detected as seeds in cattle dung. In addition, the species composition and density of seeds in cattle dung differed among three sampling seasons. Seeds of the six most prevalent species in terms of coverage were detected from cattle dung during the growing season. Hence, we conclude that it …

Geochemical And Sensor-Based Monitoring Of Fault-Associated Carbonic Springs In Grand Canyon And Northern New Mexico: Identifying Hydrologic Pathways And Establishing Baselines, Chris Mcgibbon

Earth and Planetary Sciences ETDs

This dissertation examines the interaction of spring systems and faulting. When springs discharge within a fault zone the interaction is often complex, and multiple methods are required to understand the flow, mixing and evolution of groundwater. In karst aquifer systems fracture networks can range from sub-millimeter to meters and only adds to the complexities involved in examining spring hydrology. The Interest in springs and faulting is not only driven by science, but also has applied applications. Faulting and fluid flow are of interest to the oil and gas industry, and potential CO₂ sequestration. In the southwestern US, water quantity …

Stimulation Of Ammonia Oxidizer And Denitrifier Abundances By Nitrogen Loading: Poor Predictability For Increased Soil N2o Emission, Yong Zhang, Feng Zhang, Diego Abalos, Yiqi Luo, Dafeng Hui, Bruce A. Hungate, Pablo García-Palacios, Yakov Kuzyakov, Jørgen Eivind Olesen, Uffe Jørgensen, Ji Chen

Biology Faculty Research

Unprecedented nitrogen (N) inputs into terrestrial ecosystems have profoundly altered soil N cycling. Ammonia oxidizers and denitrifiers are the main producers of nitrous oxide (N₂O), but it remains unclear how ammonia oxidizer and denitrifier abundances will respond to N loading and whether their responses can predict N-induced changes in soil N₂O emission. By synthesizing 101 field studies worldwide, we showed that N loading significantly increased ammonia oxidizer abundance by 107% and denitrifier abundance by 45%. The increases in both ammonia oxidizer and denitrifier abundances were primarily explained by N loading form, and more specifically, organic N …

The Immobilization Of Ticagrelor On Implant Materials And Corrosion And Biofouling Inhibition By Novel Layered Polymer Thin Films For Marine Application, Tell Lovelace

Electronic Theses and Dissertations

Percutaneous coronary interventions are a widely used cardiovascular surgery which is typically accompanied by the insertion of a vascular stent. After the procedure patients are put on dual anti-platelet therapy (DAPT) to prevent stent thrombosis, a common complication to this procedure in which platelets aggregate in the blood vessel on the inserted stent. Systemic deactivation of platelets in patients via oral DAPT results in patients becoming bleeding risks in future medical procedures, necessitating the development of a localized delivery system for anti-platelet medications from the surface of the stent. A novel anti-thrombogenic vascular stent coating has been prepared by covalent …

Primary Versus Secondary Gravity Wave Responses At F-Region Heights Generated By A Convective Source, C. J. Heale, P. A. Inchin, J. B. Snively

Publications

A 2D nonlinear, compressible model is used to simulate the acoustic-gravity wave (AGW, i.e., encompassing the spectrum of acoustic and gravity waves) response to a thunderstorm squall-line type source. We investigate the primary and secondary neutral AGW response in the thermosphere, consistent with waves that can couple to the F-region ionospheric plasma, and manifest as Traveling Ionospheric Disturbances (TIDs). We find that primary waves at z = 240 km altitude have wavelengths and phase speeds in the range 170–270 km, and 180–320 m/s, respectively. The secondary waves generated have wavelengths ranging from ∼100 to 600 km, and phase speeds from …

Droplet-Based Fuel Property Measurements, Wanjun Dang

LSU Doctoral Dissertations

Ongoing work to find renewable biofuels to function as drop-in replacements or blending components with gasoline has identified a large number of fuel candidates. Given the vast number of potential biomass-derived fuel molecules and limited sample sizes, screening tools are required to down-select candidate fuels having desired physical properties to ensure good engine performance. This work investigates approaches for rapid screening of candidate fuels using micro-liter sample sizes targeting four properties -- surface tension, viscosity, heat of vaporization (HOV), and vapor pressure. Measurement techniques for fuel properties are developed based on unit phenomena for liquid fuel droplets including droplet oscillation …

Sufficient Condition For The Possibility Of Completing The Pursuit, Nodirbek Umrzaqov

Scientific Bulletin. Physical and Mathematical Research

In this paper, the problem of chase is represented by a system of linear differential equations of motion dynamics. In this case, there is an integral limit to the control parameter of the evader, and a geometric limit to the control parameter of the pursuer. The pursuer is allowed to use the control that the fugitive has used so far to build his control. There are enough conditions for the game to end even if it starts from any starting point. An algorithm for constructing the control function of the pursuer is defined. It should also be noted that the …

Fast Statistical Methods For The Global Qcd Analysis Of The Proton Structure, Xiaoxian Jing

Physics Theses and Dissertations

Parton distribution functions (PDFs) quantify probabilities to find partons (quarks and gluons) in a hadron as a function of the fraction x of the hadron’s momentum carried by the parton at a given energy scale. PDFs play a critical role in precision tests of the Standard Model in Higgs boson production and other electroweak processes at the Large Hadron Collider (LHC), and in searches for physics beyond the Standard Model. PDFs are obtained by the global QCD analysis, which fits theoretical predictions to experimental measurements. PDF fitting and post-analysis are computationally intensive. This dissertation discusses fast statistical methods for the …

2021 - The Second Annual Fall Symposium Of Student Scholars

Symposium of Student Scholars Program Books

The full program book from the Fall 2021 Symposium of Student Scholars, held on November 18, 2021. Includes abstracts from the presentations and posters.

Soil Moisture Dependent Runoff In A Dryland Region: An Investigation Of The Role Of Antecedent Conditions, Monitoring, And Modeling Strategies, Gerhard Schoener

Civil Engineering ETDs

Approximately 30% of the Earth’s land surface is characterized as arid or semiarid, including much of the western United States. Accurate runoff predictions are important for informed watershed management, particularly in rapidly urbanizing areas. Infiltration excess overland flow is the dominant mechanism for runoff generation in many dryland basins, and event-based infiltration or loss models are commonly used to estimate runoff. However, predictions are associated with considerable uncertainty due to the role antecedent soil moisture, an initial condition that must be set by the modeler. The objectives of my research were to (1) evaluate the impact of antecedent soil moisture …

Discovery Of An Olivine-Type Lithium Manganese Thiophosphate, Limnps4,: Via A Building Block Approach, Srikanth Balijapelly, Kartik Ghosh, Aleksandr V. Chernatynskiy, Amitava Choudhury

Physics Faculty Research & Creative Works

An olivine-type orthothiophospate LiMnPS4 has been synthesized for the first time through a building block approach by reacting preformed ternary lithium thiophospate with MnCl2. Diffuse reflectance measurements show an optical band gap of 2.36 eV, which is further confirmed by DFT calculations. Irreversible weak ferromagnetic ordering and metamagnetism are verified through preliminary magnetic measurements.

Functional Structure Of Biomacromolecules In Plant Biomass Using Solid-State Nmr And Dynamic Nuclear Polarization, Alex Kipchirchir Kirui

LSU Doctoral Dissertations

This dissertation summarizes the recent findings on complex biomacromolecules in cell wall of plants and fungi which perform important roles in cell recognition, structural build up, and energy storage. Because of the technical difficulty in characterizing these biomacromolecules, which are often polymorphic and disordered in structure, the functional structure of these biomacromolecules remains elusive. In this dissertation, I present two solid-state nuclear magnetic resonance (ssNMR) and dynamic nuclear polarization (DNP) studies of carbohydrate-rich biosystems: the energy-rich plant biomass and disease-relevant, pathogenic fungi.

First, we have investigated the secondary cell wall of plant biomass which is a carbohydrate-rich biosystem using solid …

Biodiversity And Spatial Heterogeneity In Semi-Natural Grasslands In A Mountain Area In Slovakia, Masae Shiyomi, N. Gáborèík, H. Koizumi, A. Javorkova, E. Uhliarova, O. Jezikova

IGC Proceedings (1977-2023)

The spatial pattern of vegetation in the following 3 semi-natural grasslands in Banska Bystrica, Slovakia, was observed in August, 1998: (1) a grassland sown with improved herbage plants after plowing in 1991, (2) a grassland oversown with improved herbage plants in 1991, and (3) a natural grassland without any treatment at the time of establishment. A new method of measuring vegetation was adopted: in each grassland, 50 quadrats 50 cm × 50 cm, composed of 4 smaller cells 25 cm × 25 cm, were set up, and all the species in each cell were recorded. The sown grassland displayed the …

Optimum Area Of Semi-Natural Grassland To Maintain Maximum Butterfly And Avian Species Richness In Japan, A. Shoji, K. Kohyama, H. Sasaki

IGC Proceedings (1977-2023)

To evaluate the optimum area of semi-natural grassland to maintain maximum butterfly and avian species richness in Japan, digitalized grid data of butterfly and avian distribution, as well as vegetation distribution, throughout the country were used. After obtaining logistic regression models explaining the probabilities of occurrence of each species with semi-natural grassland area and latitude as variables, the optimum value was calculated. The expected maximum species richness of butterflies in the country was the highest in the case of about 40 square kilometers of semi-natural grassland per 100 square kilometers, though the value varied somewhat with latitude. The expected maximum …

Managing Grassy Woodlands: Balancing Production And Conservation Of Resources, John G. Mcivor, Neil D. Macleod, S. Mcintyre

IGC Proceedings (1977-2023)

Eastern Australian eucalypt woodlands are important agricultural areas that have been widely modified during two centuries of European-style use. Despite this they contain important natural resources including significant biodiversity. Long term sustainability of production depends on maintaining resources and management must be for both production and conservation. A research program on four properties in south east Queensland showed the properties were in generally good condition although all had some problems, and has highlighted a number of significant costs and barriers to adopting a more balanced approach to production and conservation.

Species Segregation And Functional Groups In The Hill Country Of New Zealand, I. López, I. Valentine, D. Hedderley, M. G. Lambert

IGC Proceedings (1977-2023)

In the hill country of New Zealand, the soil-sward relationship on hill microrelief was studied. Three categories of slope or microsites were distinguished: low, medium and high. The hypothesis was that soil variables of neighbouring microsites differ, and because of this, there is a segregation of species or functional groups of species between the microsites. Soil features, botanical composition and total annual yield were measured in the slope categories in two similar paddocks; one of which had received long-term phosphorus fertilisation and a non-fertilised paddock. ANOVA, cluster analysis and canonical variate analysis were performed on the data. Unsaturated hydraulic conductivity, …

Convergence Properties Of Solutions Of A Length-Structured Density-Dependent Model For Fish, Geigh Zollicoffer

Rose-Hulman Undergraduate Mathematics Journal

We numerically study solutions to a length-structured matrix model for fish populations in which the probability that a fish grows into the next length class is a decreasing nonlinear function of the total biomass of the population. We make conjectures about the convergence properties of solutions to this equation, and give numerical simulations which support these conjectures. We also study the distribution of biomass in the different age classes as a function of the total biomass.

Comparing The Efficiency Of A Marsh-Sill And Oyster Reef Balls In Attenuating Waves, Navid Tahvildari, Alexa Leone

December 17, 2021: Natural and Nature-Based Solutions (Part 2)

No abstract provided.