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2020

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Articles 421 - 450 of 15205

Full-Text Articles in Physical Sciences and Mathematics

Understanding The Role Of Atom Trapping In The Evolution Of Hydrocarbon Transformation Catalyst Morphology, Griffin Canning Dec 2020

Understanding The Role Of Atom Trapping In The Evolution Of Hydrocarbon Transformation Catalyst Morphology, Griffin Canning

Chemistry and Chemical Biology ETDs

Converting alkanes to other, more chemically and economically valuable molecules requires catalysts that can survive elevated temperatures and highly reducing environments. These environments can cause many metal-nanoparticle based catalysts to sinter rapidly, causing a loss of activity. They must also tolerate the coke formation, as well, since coke can restrict access to active sites by gas phase molecules, thus lowering catalytic activity. While there are routes to improve both the sinter and coke resistance of catalysts, an alternative strategy is to develop a protocol for regenerating the activity of the catalyst in question when coke formation or sintering becomes problematic. …


The Ideal Dog, Owen Graham Dec 2020

The Ideal Dog, Owen Graham

Fall Student Research Symposium 2020

The goal of this project was to look into all of the different jobs or tasks that we as humans have dogs perform and try to pinpoint what exactly it is that makes a dog ideal for each task. After identifying desirable characteristics, I considered physical traits in order to create an ideal dog that would be able to perform the greatest number of jobs possible.


National Security & Climate Change, Madison Mortensen Dec 2020

National Security & Climate Change, Madison Mortensen

Fall Student Research Symposium 2020

Certain scientific subjects are often divisive or technical, which makes those topics difficult to discuss with audiences outside the scientific sphere. One way of getting around this obstacle is to cater scientific communication to different target audiences to cut through any audience biases. In order to accomplish that, a communicator needs to understand the relationship between audiences' worldviews, and what they know, feel, and do regarding the subject at hand, and then how that relationship influences the types of media audiences trust and to which they respond positively. The following study investigates the worldviews of a military audience with respect …


(2,3)-Cordial Digraphs, Jonathan Mousley, Manuel Santana Dec 2020

(2,3)-Cordial Digraphs, Jonathan Mousley, Manuel Santana

Fall Student Research Symposium 2020

This presentation is about graphs (the vertex-edge kind, not the y = f(x) kind). A graph is a mathematical object that represents objects and some relationship among them; the objects are represented by vertices and the relationships are represented by the edges. Graphs have applications in just about every field imaginable, including artificial intelligence, social network theory, and parallel computing theory. A directed graph is a type of graph used to represent relationships that are one-sided or not symmetric. We discuss a graph labeling scheme on directed graphs introduced by LeRoy Beasley called a (2,3)-cordial labeling. In …


Galactic Sources In Gamma-Ray Diffuse Emission, Melissa Rasmussen Dec 2020

Galactic Sources In Gamma-Ray Diffuse Emission, Melissa Rasmussen

Fall Student Research Symposium 2020

The Fermi Large Area Telescope (LAT) has detected hundreds of Galactic gamma-ray sources, most of them pulsars. But the Galaxy contains tens of thousands of such sources which are still undetected due to their low flux, or because of conflation of the foreground with sources. Characterizing the general properties of detected sources would allow us to estimate the contribution to the diffuse Galactic emission from these undetected sources and in turn it would help the detection of new sources and even searches for dark matter. We present updates on our long-term effort to characterize the general properties of Galactic gamma-ray …


Synthesizing Octahedral Polyomavirus Capsids For Cryogenic Electron Microscopy, Miles Robertson Dec 2020

Synthesizing Octahedral Polyomavirus Capsids For Cryogenic Electron Microscopy, Miles Robertson

Fall Student Research Symposium 2020

Polyomavirus capsids are polymorphic under different chemical conditions. These capsids have been synthesized artificially using purified VP1, the primary building block of the capsid. Five VP1 proteins come together and form a highly stable structure called a pentamer, and these pentamers can form capsids (Figure 1). Depending on chemical conditions, the capsids can form three distinct sizes: T=7, octahedral and icosahedral (Figure 2). Only one form is found in infectious virions, and its structure has been well studied. However, no high-resolution structure of the octahedral capsid currently exists. The goal of this research is to solve the structure of the …


Enabling Mars Farms Through Microbial Remediation Of Wastewater, Tyler Wallentine Dec 2020

Enabling Mars Farms Through Microbial Remediation Of Wastewater, Tyler Wallentine

Fall Student Research Symposium 2020

This research evaluates the capacity of photoheterotrophic purple non-sulfur bacteria to utilize wastewater organics to grow and produce nitrogen-rich biomass. Inhibitory components of wastewater are determined. A scaled up production system is designed and utilized to culture bacteria in wastewater. The application of this technology in the production of agriculturally viable amounts of nitrogen-rich biomass is evaluated in the context of a Mars mission and enabling agriculture in a barren environment.


Autocart: Spatially-Aware Regression Trees For Ecological And Spatial Modeling, Ethan Ancell Dec 2020

Autocart: Spatially-Aware Regression Trees For Ecological And Spatial Modeling, Ethan Ancell

Fall Student Research Symposium 2020

Many ecological and spatial processes are complex in nature and are not accurately modeled by linear models. Regression trees promise to handle the high-order interactions that are present in ecological and spatial datasets, but fail to produce physically realistic characterizations of the underlying landscape. The "autocart'' (autocorrelative regression trees) R package extends the functionality of previously proposed spatial regression tree methods through a spatially aware splitting function and novel adaptive inverse distance weighting method in each terminal node. The efficacy of these autocart models, including an autocart extension of random forest, is demonstrated on multiple datasets. This highlights the ability …


Pure Breeding At Its Finest, Justin Hunter Dec 2020

Pure Breeding At Its Finest, Justin Hunter

Fall Student Research Symposium 2020

This is a poster of my research on the affects pure breeding has on dogs and their health. There is a focus as well on the focus on neoteny and its affects on dogs.


Dogs In The Home Improve The Quality Of Life Of The People Living Inside, Tanner Stevenson Dec 2020

Dogs In The Home Improve The Quality Of Life Of The People Living Inside, Tanner Stevenson

Fall Student Research Symposium 2020

This poster explores how dogs improve the quality of life of the people they interact with. Regardless of underlying issues that the human faces, every dog helps to improve the situation of that human. From service animals helping to improve the quality of life of their owners in other ways than what meets the eye, to dogs improving the chance of allergy immunity for children, dogs impact the lives of humans for good. This project explores the way that studies have proven the worth of the dog in the home.


The Age And Origin Of Precambrian Orthogneiss Of The Grouse Creek Block, Northern Utah And Southern Idaho, Skadi Kobe Dec 2020

The Age And Origin Of Precambrian Orthogneiss Of The Grouse Creek Block, Northern Utah And Southern Idaho, Skadi Kobe

Fall Student Research Symposium 2020

New geochronologic and isotopic analyses from the Grouse Creek block (GC) provide insight into the assembly of western Laurentia during the late Archean to Paleoproterozoic and establish the influence of the GC in the evolution of Yellowstone-Snake River Plain hotspot magmatism in the central Snake River Plain. The GC is primarily exposed in the Albion-Raft River-Grouse Creek metamorphic core complex of northern Utah and southern Idaho and includes a complex assemblage of orthogneiss, schist, amphibolite, and metasediments intruded by Oligocene plutons and overlain by Cenozoic sedimentary units. Many investigations of the GC have focused on the structural evolution of the …


Isolation Of Halotolerant Bacteria From The Rhizosphere Of Ceanothus Velutinus May Lead To Contributions In Plant Health In Saline Conditions, Jacob Davis Dec 2020

Isolation Of Halotolerant Bacteria From The Rhizosphere Of Ceanothus Velutinus May Lead To Contributions In Plant Health In Saline Conditions, Jacob Davis

Fall Student Research Symposium 2020

The recent rise in the average global temperature has been a driving force over the past few years for rising soil salinity. This presents an especially hostile environment to many plant species that may not have previously been exposed to these conditions. The rhizosphere, which is a layer of soil attached to the roots of a plant, contains microorganisms that contribute to the plants' abiotic and biotic stress resistance. These microorganisms are known as Plant Growth Promoting Rhizobacteria (PGPR). These can play a key role in contributing to plant stress resistance. Some native plants have shown a strong ability to …


Why Dogs Are Feared, Hannah Ericson Dec 2020

Why Dogs Are Feared, Hannah Ericson

Fall Student Research Symposium 2020

From German Shepherds to Pit bulls, a specific breed of dog is often singled out as being more dangerous than the others. There are stories and myths behind the behavior of such breeds, as well as simply looking scary. In this presentation, I will discuss why certain traits in dogs promote fear (such as dark coloring) and why certain breeds promote fear - such as a modern day prejudice that is quite similar to racism in the human society.


Cloning Type Iv-B Crispr System Into A Plasmid, Olivia Gornichec, Kailey Welch Dec 2020

Cloning Type Iv-B Crispr System Into A Plasmid, Olivia Gornichec, Kailey Welch

Fall Student Research Symposium 2020

Bacterial CRISPR-Cas systems have recently been repurposed as RNA-guided genome editors in research labs across the world. Yet CRISPR-Cas adaptive immune systems are very diverse and many systems remain uncharacterized. Discovering the structure and function of newly discovered and uncharacterized systems may further advance existing genome editing technologies, or lead to new ones. To better understand the function of the little-researched Type IV-B system we cloned the genes of a Type IV-B system from Mycobacterium J623 into a plasmid containing a target sequence of a Type IV-A and Type V system. The Type IV-B system was placed on the target …


Isolation And Purification Of Bacterial Species From Rhizosphere Of Native Plant Ceanothus Velutinus (Snowbrush), Katherine Webb, Hayden Johns Dec 2020

Isolation And Purification Of Bacterial Species From Rhizosphere Of Native Plant Ceanothus Velutinus (Snowbrush), Katherine Webb, Hayden Johns

Fall Student Research Symposium 2020

Due to the ever-changing climate, plants face stressors that limit their growth. Therefore it is vital to find new ways to protect plants from biotic and abiotic stressors such as pathogen infection, drought, heavy metal poisoning, and salinity. With an increasing population, limiting the effects of stress on plant growth and development for agriculture is vital. One approach to this is focusing on beneficial plant-microbe interaction, such as plant growth-promoting rhizobacteria (PGPR). These bacteria are found in the rhizosphere- the soil that is attached to the roots of a plant. Various PGPRs share a symbiotic relationship with plants and help …


The Impact Of Biological Components On A Dog's Personality, Kinsley Batson Dec 2020

The Impact Of Biological Components On A Dog's Personality, Kinsley Batson

Fall Student Research Symposium 2020

We interact with dogs every day, and they are often referred to as "man's best friend." But what makes a dog the happy-go-lucky, cuddly fur ball of happiness that so many love? Similar to humans, there is a nature vs. nurture debate on what shapes a dog's personality. While it is likely a mixture of both, I've researched a variety of biological components that help to make a dog a dog. Some of these include face shape, how their brain responds to audio stimuli, and a specific gene, also found in children with Williams syndrome, that is thought to make …


Dog-Headed: Outcast To All, Wesley Mills Dec 2020

Dog-Headed: Outcast To All, Wesley Mills

Fall Student Research Symposium 2020

Cynocephali are a group of mythological, dog-headed, humans that appear throughout various cultures. Despite the wide range of region and time period in which they are used, they consistently represent a quality of "otherness".


Synthesis Of Structurally Diverse Molecular Scaffolds Enabled By Protected Oxyallyl Cations, Joshua Andrew Malone Dec 2020

Synthesis Of Structurally Diverse Molecular Scaffolds Enabled By Protected Oxyallyl Cations, Joshua Andrew Malone

LSU Doctoral Dissertations

This dissertation focuses on the synthesis of diverse molecular scaffolds through the use of protected oxyallyl cation intermediates. Chapter One provides background on the generation and applications of oxyallyl and silyloxyallyl cations, while focusing on the direct nucleophilic capture of theses intermediates to generate functionalized ketones and silylenolates. Chapter Two depicts our approach to generate six-membered silyloxyallyl cations through the use of mild Brønsted acid activation. Regioselective nucleophilic capture of these intermediates successfully produced diverse a,a’-substituted silylenol ethers enabled by polar solvent and residual water.

Chapter three details strategies to generate 1,4-dicarbonyl compounds, focusing on the capture of cationic intermediates …


Distributed De Novo Assembler For Large-Scale Long-Read Datasets, Sayan Goswami, Kisung Lee, Seung Jong Park Dec 2020

Distributed De Novo Assembler For Large-Scale Long-Read Datasets, Sayan Goswami, Kisung Lee, Seung Jong Park

Computer Science Faculty Research & Creative Works

Third-generation DNA sequencing technologies such as single-molecule real-time sequencing (SMRT) and nanopore sequencing have the potential to fill the gaps in the existing genome databases since the raw sequences produced by these machines are much longer than those of previous generations and therefore result in more contiguous assemblies. However, these long reads have a high error rate, which makes the assembly process computationally challenging. Moreover, since existing long-read assemblers are designed to run on a single machine, they either take days to complete or run out of memory on even moderate-sized datasets. In this paper, we present a distributed long-read …


Modeling Reflectance Spectra Of Nanorod Arrays With Arrays Of Light Sources, Christian Lange Dec 2020

Modeling Reflectance Spectra Of Nanorod Arrays With Arrays Of Light Sources, Christian Lange

Fall Student Research Symposium 2020

It is known that carbon-nanotube forests, nanopillar arrays, and other formations of quasi-periodic nanostructures of various materials (semiconductors, semimetals, and metals) can display a very low light reflectance over a wide range of wavelengths, and that the reflectance eventually starts to rise beyond an onset wavelength. As these materials can be quite reflective in planar form, this phenomenon indicates that morphology rather than material plays a dominant role. However, a quantitative analysis of the reflectance spectra of periodic structures has yet to be established. As a first step, we use an array of light sources to model the reflection from …


A Comparison Of The Efficacy Of Methane-Oxidizing Alternative Daily Landfill Covers And Policy Recommendations For Landfill Regulatory Agencies, Eric Lara Dec 2020

A Comparison Of The Efficacy Of Methane-Oxidizing Alternative Daily Landfill Covers And Policy Recommendations For Landfill Regulatory Agencies, Eric Lara

Master's Projects and Capstones

Methane (CH4) is a potent greenhouse gas (GHG) that has 28-36 times the greenhouse effect of carbon dioxide (CO2) over a 100-year timespan. Recent remote sensing research conducted by NASA Jet Propulsion Laboratory and Scientific Aviation has indicated that the working face of landfills are sectors of much higher methane emissions than previously considered. A working face location, which is the area of the landfill where daily waste is deposited, lacks the engineering controls present on the rest of the landfill. Controls such as gas collection and extraction wells and substantial covers to ensure surface integrity for methane leaks are …


Policy Changes Impact In Deforestation Of The Brazilian Amazon, Iara Silva Jaques Dec 2020

Policy Changes Impact In Deforestation Of The Brazilian Amazon, Iara Silva Jaques

Master's Projects and Capstones

Since discovered and inhabited, the Brazilian Amazon has been explored and impacted negatively by human activities. The conversion of forest to pastureland and farmland, as well as mining activities, road opening, wood and ore extraction and fire are historically the main causes of environmental damages and forest loss in the region. This project overviewed the latest changes in environmental policy and practices towards environmental protection conducted by the Brazilian president Jair Bolsonaro, since he took office in 2019, and analyzed the progress of deforestation in the recent years under the new federal administration. Geographic Information System analysis were used to …


Instrumentation And Application Of Image-Charge Detection Of Electrospray-Charged Microparticles And Microdroplets, Jiuzhi Gao Dec 2020

Instrumentation And Application Of Image-Charge Detection Of Electrospray-Charged Microparticles And Microdroplets, Jiuzhi Gao

Theses and Dissertations

Image-charge detection is emerging as an important tool to analyze heavy and heterogeneous samples because of its unique advantages in measuring highly charged microparticles. Conventional image-charge detection instruments include at least three fundamental components: an ionization source, an aerodynamic particle delivery system, and an image-charge detector. Here I report research efforts that investigated the mechanisms of image-charge detection and proposed some instrumental developments of these components to suit specific research purposes. In Chapter 2, I report an investigation of the electrospray ionization (ESI) mechanism based on an observation that a certain portion of charged particles generated with an ESI source …


Reconstructing Carbon Dynamics Of Alpine And Temperate Zone Lakes Using Stable Isotopic Analysis, Rebecca M. Doyle Dec 2020

Reconstructing Carbon Dynamics Of Alpine And Temperate Zone Lakes Using Stable Isotopic Analysis, Rebecca M. Doyle

Electronic Thesis and Dissertation Repository

Lake sediments integrate signals from the catchment, atmosphere and water column, offering a unique window through which to view changes in the carbon cycle. Carbon dynamics in lakes are changing due to nitrogen loading and anthropogenic climate warming (ACW), threatening the water quality of lakes. This thesis identifies how the carbon dynamics of lakes have responded to anthropogenically-driven forcings by comparing pre- and post- AD 1850 records preserved in lake sediments. First, the carbon dynamics of Barry Lake (Ontario, Canada), a low-elevation temperate lake, are investigated. Effective moisture (the net of water inputs and evaporation) is reconstructed using the carbon …


Longitudinal Partitioning Waveform Relaxation Methods For The Analysis Of Transmission Line Circuits, Tarik Menkad Dec 2020

Longitudinal Partitioning Waveform Relaxation Methods For The Analysis Of Transmission Line Circuits, Tarik Menkad

Electronic Thesis and Dissertation Repository

Three research projects are presented in this manuscript. Projects one and two describe two waveform relaxation algorithms (WR) with longitudinal partitioning for the time-domain analysis of transmission line circuits. Project three presents theoretical results about the convergence of WR for chains of general circuits.

The first WR algorithm uses a assignment-partition procedure that relies on inserting external series combinations of positive and negative resistances into the circuit to control the speed of convergence of the algorithm. The convergence of the subsequent WR method is examined, and fast convergence is cast as a generic optimization problem in the frequency-domain. An automatic …


Addendum For The Article Radio Graceful Labelling Of Graphs, Laxman Saha, Alamgir Rahaman Basunia Dec 2020

Addendum For The Article Radio Graceful Labelling Of Graphs, Laxman Saha, Alamgir Rahaman Basunia

Theory and Applications of Graphs

Additional references listed for the article: Saha, Laxman and Basunia, Alamgir Rahaman (2020) "Radio Graceful Labelling of Graphs," Theory and Applications of Graphs: Vol. 7: Iss. 1, Article 7. DOI: 10.20429/tag.2020.070107


A - Separately Subharmonic Functions., Sevdiyor Akramovich Imomkulov, S.M. Abdikodirov, R. Sharipov Dec 2020

A - Separately Subharmonic Functions., Sevdiyor Akramovich Imomkulov, S.M. Abdikodirov, R. Sharipov

Central Asian Problems of Modern Science and Education

In this work we give a definition of a -separately subharmonic function


Approximate Solution Of An Initial-Boundary Value Problem For An Nonhomogeneous Second-Order Differential Equation Of Mixed Type With Two Degenerate Lines, Yashin Komilovich Khudayberganov Dec 2020

Approximate Solution Of An Initial-Boundary Value Problem For An Nonhomogeneous Second-Order Differential Equation Of Mixed Type With Two Degenerate Lines, Yashin Komilovich Khudayberganov

Central Asian Problems of Modern Science and Education

This work is devoted to the study of an approximate solution of the initial-boundary value problem for the second order mixed type nonhomogeneous differential equation with two degenerate lines. Similar equations have many different applications, for example, boundary value problems for mixed type equations are applicable in various fields of the natural sciences: in problems of laser physics, in magneto hydrodynamics, in the theory of infinitesimal bindings of surfaces, in the theory of shells, in predicting the groundwater level, in plasma modeling, and in mathematical biology. In this paper, based on the idea of A.N. Tikhonov, the conditional correctness of …


Cartesian Product Of Regular Parabolic Manifolds., Alimardon Atamuratov Dec 2020

Cartesian Product Of Regular Parabolic Manifolds., Alimardon Atamuratov

Central Asian Problems of Modern Science and Education

We consider the regular parabolic manifold X and polynomials on it. It is proved regularity of Cartesian product of regular parabolic manifolds and described polynomials.


Leveraging Image Analysis To Compute 3d Plant Phenotypes Based On Voxel-Grid Plant Reconstruction, Sruti Das Choudhury, Srikanth Maturu, Ashok Samal, Vincent Stoerger, Tala Awada Dec 2020

Leveraging Image Analysis To Compute 3d Plant Phenotypes Based On Voxel-Grid Plant Reconstruction, Sruti Das Choudhury, Srikanth Maturu, Ashok Samal, Vincent Stoerger, Tala Awada

School of Natural Resources: Faculty Publications

High throughput image-based plant phenotyping facilitates the extraction of morphological and biophysical traits of a large number of plants non-invasively in a relatively short time. It facilitates the computation of advanced phenotypes by considering the plant as a single object (holistic phenotypes) or its components, i.e., leaves and the stem (component phenotypes). The architectural complexity of plants increases over time due to variations in self-occlusions and phyllotaxy, i.e., arrangements of leaves around the stem. One of the central challenges to computing phenotypes from 2-dimensional (2D) single view images of plants, especially at the advanced vegetative stage in presence of self-occluding …