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Articles 62161 - 62190 of 294596

Full-Text Articles in Physical Sciences and Mathematics

A Uniform Chevalley Theorem For Direct Summands Of Polynomial Rings In Mixed Characteristic, Alessandro De Stefani, Eloisa Grifo, Jack Jeffries Apr 2022

A Uniform Chevalley Theorem For Direct Summands Of Polynomial Rings In Mixed Characteristic, Alessandro De Stefani, Eloisa Grifo, Jack Jeffries

Department of Mathematics: Faculty Publications

We prove an explicit uniform Chevalley theorem for direct summands of graded polynomial rings in mixed characteristic. Our strategy relies on the introduction of a new type of differential powers that does not require the existence of a p-derivation on the direct summand.

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Exploring The Kinetics And Thermodynamics Of O–H Bond Activation By Tripodal Tris(Nitroxide) Aluminum And Gallium Complexes, Joseph S. Scott , '22 Apr 2022

Exploring The Kinetics And Thermodynamics Of O–H Bond Activation By Tripodal Tris(Nitroxide) Aluminum And Gallium Complexes, Joseph S. Scott , '22

Senior Theses, Projects, and Awards

Aluminum is one of earth’s most abundant and cheapest metals, and it is also nontoxic and environmentally friendly. This makes it an ideal candidate to be implemented in organometallic chemistry as a greener alternative to metal-based systems based on heavy and/or precious metals. One of the realms in which aluminum and other group 13 elements show promise is metal-ligand cooperative chemistry, which can afford transition metal-reminiscent small molecule activation chemistry. Our studies of organic ligands with nitroxide-functionalities within Al and Ga coordinative systems has led us to the discovery of tripodal tris(nitroxide) Al and Ga complexes with abilities to engage …

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Design And Application Of Membrane Nanodiscs For Biophysical Studies Of Influenza A Proteins, Aye K. Kyaw , '22 Apr 2022

Design And Application Of Membrane Nanodiscs For Biophysical Studies Of Influenza A Proteins, Aye K. Kyaw , '22

Senior Theses, Projects, and Awards

Membrane proteins play a range of important roles in biological systems, yet they are underrepresented in the data base of high-resolution structures of all proteins. There is intense interest in developing new methodologies for studying membrane proteins. An essential step to membrane protein method development is devising reliable membrane mimics in which to embed membrane proteins. The goal of this thesis was to develop and apply nanodisc membrane mimics to the study of an influenza A membrane protein called M2. Nanodiscs provide a lipid bilayer environment with access to both sides of the bilayer and are smaller than commonly used …

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Instructor Selection And Use Of Virtual Field Experiences In College Geoscience Course, Kristen Foley Apr 2022

Instructor Selection And Use Of Virtual Field Experiences In College Geoscience Course, Kristen Foley

Masters Theses

Virtual Field Experiences (VFEs) are a growing supplement and gateway to traditional fieldwork in the geosciences. With VFEs becoming more accepted for use in college geoscience courses, how instructors find and choose VFEs for their students is critical to creating greater accessibility and future resources. VFEs that are not easily accessed by instructors may go unused, and the effort put into making them would have been wasted. This phenomenological descriptive study utilized five focus groups of college geoscience instructors in the United States. Each 1-to-1.5-hour focus group session of 3-7 participants took place on video conferencing software, which was recorded …

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Cover Crops May Exacerbate Moisture Limitations On South Texas Dryland Farms, Stephanie Kasper, Faeqa Mohsin, Lindsey Richards, Alexis Racelis Apr 2022

Cover Crops May Exacerbate Moisture Limitations On South Texas Dryland Farms, Stephanie Kasper, Faeqa Mohsin, Lindsey Richards, Alexis Racelis

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

Cover crops are a sustainable management tool for mediating weed pressure, reducing soil erosion, and enhancing soil organic carbon (C) and nitrogen (N) levels. Yet, adoption rates across water-limited farms in Texas remain low, especially among producers without irrigation access, due to concerns that cover crop use of soil moisture will negatively impact subsequent cash crop yields. This three-year cover crop trial in a rain-fed sorghum (Sorghum bicolor L.) farm in Lyford, Texas, trialed different cover crop mixes and seeding rates and confirmed that cover cropping leads to significant soil moisture deficits and cash crop failure when rainfall is low …

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How Can Generative Adversarial Networks Impact Computer Generated Art? Insights From Poetry To Melody Conversion, Sakib Shahriar, Noora Al Roken Apr 2022

How Can Generative Adversarial Networks Impact Computer Generated Art? Insights From Poetry To Melody Conversion, Sakib Shahriar, Noora Al Roken

All Works

Recent advances in deep learning and generative adversarial networks (GANs), in particular, has enabled interesting applications including photorealistic image generation, image translation, and automatic caption generation. This has opened up possibilities for many cross-domain applications in computer generated arts and literature. Although there are existing software-based approaches for generating musical accompaniment of a given poetry, there are no existing implementation using GANs. This work proposes a novel poetry to melody generation conditioned on poem emotion using GANs. A dataset containing pairs of poetry and melody based on three emotion categories is introduced. Furthermore, various GAN architectures including SpecGAN and WaveGAN …

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Rescuecastr: Exploring Photos And Live Streaming To Support Contextual Awareness In The Wilderness Search And Rescue Command Post, Brennon Jones, Anthony Tang, Carman Neustaedter Apr 2022

Rescuecastr: Exploring Photos And Live Streaming To Support Contextual Awareness In The Wilderness Search And Rescue Command Post, Brennon Jones, Anthony Tang, Carman Neustaedter

Research Collection School Of Computing and Information Systems

Wilderness search and rescue (WSAR) is a command-and-control activity where a Command team manages field teams scattered across a large area looking for a lost person. The challenge is that it can be difficult for Command to maintain awareness of field teams and the conditions of the field. We designed RescueCASTR, an interface that explores the idea of deploying field teams with wearable cameras that stream live video or sequential photos periodically to Command that aid contextual awareness. We ran a remote user study with WSAR managers to understand the opportunities and challenges of such a system. We found that …

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Estimating Stranded Coal Assets In China's Power Sector, Weirong Zhang, Mengjia Ren, Junjie Kang, Yiou Zhou, Jiahai Yuan Apr 2022

Estimating Stranded Coal Assets In China's Power Sector, Weirong Zhang, Mengjia Ren, Junjie Kang, Yiou Zhou, Jiahai Yuan

Research Collection School Of Computing and Information Systems

China has suffered overcapacity in coal power since 2016. With growing electricity demand and an economic crisis due to the Covid-19 pandemic, China faces a dilemma between easing restrictive policies for short-term growth in coal-fired power production and keeping restrictions in place for long-term sustainability. In this paper, we measure the risks faced by China's coal power units to become stranded in the next decade and estimate the associated economic costs for different shareholders. By implementing restrictive policies on coal power expansion, China can avoid 90% of stranded coal assets by 2025.

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Chosen-Instruction Attack Against Commercial Code Virtualization Obfuscators, Shijia Li, Chunfu Jia, Pengda Qiu, Qiyuan Chen, Jiang Ming, Debin Gao Apr 2022

Chosen-Instruction Attack Against Commercial Code Virtualization Obfuscators, Shijia Li, Chunfu Jia, Pengda Qiu, Qiyuan Chen, Jiang Ming, Debin Gao

Research Collection School Of Computing and Information Systems

—Code virtualization is a well-known sophisticated obfuscation technique that uses custom virtual machines (VM) to emulate the semantics of original native instructions. Commercial VM-based obfuscators (e.g., Themida and VMProtect) are often abused by malware developers to conceal malicious behaviors. Since the internal mechanism of commercial obfuscators is a black box, it is a daunting challenge for the analyst to understand the behavior of virtualized programs. To figure out the code virtualization mechanism and design deobfuscation techniques, the analyst has to perform reverse-engineering on large-scale highly obfuscated programs. This knowledge learning process suffers from painful cost and imprecision. In this project, …

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Trend: Temporal Event And Node Dynamics For Graph Representation Learning, Zhihao Wen, Yuan Fang Apr 2022

Trend: Temporal Event And Node Dynamics For Graph Representation Learning, Zhihao Wen, Yuan Fang

Research Collection School Of Computing and Information Systems

Temporal graph representation learning has drawn significant attention for the prevalence of temporal graphs in the real world. However, most existing works resort to taking discrete snapshots of the temporal graph, or are not inductive to deal with new nodes, or do not model the exciting effects which is the ability of events to influence the occurrence of another event. In this work, We propose TREND, a novel framework for temporal graph representation learning, driven by TempoRal Event and Node Dynamics and built upon a Hawkes process-based graph neural network (GNN). TREND presents a few major advantages: (1) it is …

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A Survey On Modern Deep Neural Network For Traffic Prediction: Trends, Methods And Challenges, David Alexander Tedjopumomo, Zhifeng Bao, Baihua Zheng, Farhana Murtaza Choudhury, Kai Qin Apr 2022

A Survey On Modern Deep Neural Network For Traffic Prediction: Trends, Methods And Challenges, David Alexander Tedjopumomo, Zhifeng Bao, Baihua Zheng, Farhana Murtaza Choudhury, Kai Qin

Research Collection School Of Computing and Information Systems

In this modern era, traffic congestion has become a major source of negative economic and environmental impact for urban areas worldwide. One of the most efficient ways to mitigate traffic congestion is through future traffic prediction. The field of traffic prediction has evolved greatly ever since its inception in the late 70s. Earlier studies mainly use classical statistical models such as ARIMA and its variants. Then, researchers started to focus on machine learning models due to their power and flexibility. As theoretical and technological advances emerge, we enter the era of deep neural network, which gained popularity due to its …

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Diatom Response To Different Hydrologic Sources In Alpine Streams: A Teton Range Case Study, Shannon Weld Apr 2022

Diatom Response To Different Hydrologic Sources In Alpine Streams: A Teton Range Case Study, Shannon Weld

Water Resources Professional Project Reports

Alpine stream diversity is due in part to different hydrological sources including snowpack, surface glaciers, and rock glaciers; climate change threatens to homogenize these sources. Surprisingly little is understood about algal communities in these stream types. We characterized algal communities and water chemistry among ten alpine streams from these sources in the Teton Range, Wyoming, USA. Late summer sampling (2019-2021) included diatoms, anions, cations, and water quality parameters. Data were analyzed using one- and two-way analysis of variance, principal component analysis, and nonmetric multidimensional scaling. There were statistically significant differences among some or all hydrologic sources for temperature, dissolved oxygen, …

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Nm Stat § 7-36-20: Disconnected Land And Water Policy In A Climate-Altered Peri-Urban Fringe, Annalise Porter Apr 2022

Nm Stat § 7-36-20: Disconnected Land And Water Policy In A Climate-Altered Peri-Urban Fringe, Annalise Porter

Water Resources Professional Project Reports

New Mexico (NM) passed a land use law in 1967 that offers tax subsidies to agricultural landowners and is implemented at the county level. This law illustrates a stark disconnect between land and water policy: there are water policy implications because of it, but it has never been discussed accordingly. With a focus on New Mexico’s primary urban county, this study estimates that in 2020, Rio Grande surface flows were used to irrigate 4,388 acres of Bernalillo County land that received the special tax valuation offered through the law. This represents a potential use of nearly 11,000 acre-feet of water, …

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When High-Water-Use Neighbors Move In: Farming Pecans In Valencia County, New Mexico, Tylee M. Griego Apr 2022

When High-Water-Use Neighbors Move In: Farming Pecans In Valencia County, New Mexico, Tylee M. Griego

Water Resources Professional Project Reports

Valencia County, comprised of a collection of farming communities in the Middle Rio Grande of central New Mexico, is undergoing a fundamental change in its irrigated agriculture. Historically, over recent decades, it has had many smaller-sized farms, or “hobby farms”, with fewer larger commercial enterprises, and with alfalfa as its dominant crop. But in recent years, it has seen a significant expansion of acreage devoted to pecan orchards – a higher value commercial crop that also is substantially higher in water use. Some of these orchards have been planted on land not previously irrigated. The Rio Grande flows through the …

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Deep Convolutional Neural Network-Based System For Fish Classification, Ahmad Al Smadi, Atif Mehmood, Ahed Abugabah, Eiad Almekhlafi, Ahmad Mohammad Al-Smadi Apr 2022

Deep Convolutional Neural Network-Based System For Fish Classification, Ahmad Al Smadi, Atif Mehmood, Ahed Abugabah, Eiad Almekhlafi, Ahmad Mohammad Al-Smadi

All Works

In computer vision, image classification is one of the potential image processing tasks. Nowadays, fish classification is a wide considered issue within the areas of machine learning and image segmentation. Moreover, it has been extended to a variety of domains, such as marketing strategies. This paper presents an effective fish classification method based on convolutional neural networks (CNNs). The experiments were conducted on the new dataset of Bangladesh’s indigenous fish species with three kinds of splitting: 80-20%, 75-25%, and 70-30%. We provide a comprehensive comparison of several popular optimizers of CNN. In total, we perform a comparative analysis of 5 …

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Estimation Of Radium-226 Concentrations In Produced Water From Shale Gas, Tight Gas And Conventional Hydrocarbon Wells, Richard Frank Haaker Apr 2022

Estimation Of Radium-226 Concentrations In Produced Water From Shale Gas, Tight Gas And Conventional Hydrocarbon Wells, Richard Frank Haaker

Mathematics & Statistics ETDs

This study examined data from the United States Geological Survey Produced Water database, version 2.3 (USGS DB) and built models to estimate the concentration of radium-226 in produced water given the values of other predictor variables. The dataset had only about 254 observations that were useable. Although the USGS DB had up to 190 possible attributes, it also had extreme rates of missingness, and many of the candidate variables were highly correlated. Multiple imputation techniques were employed using the Mice, Hmisc, and RMS packages for the R language to deal with the missing data. A multiple linear regression and two …

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Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo–Virgo Run O3b, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang Apr 2022

Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo–Virgo Run O3b, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC–2020 March 27 17:00 UTC). We conduct two independent searches: a generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence …

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Galaxy And Mass Assembly (Gama): The Weak Environmental Dependence Of Quasar Activity At 0.1 < Z < 0.35, Clare F. Wethers, Nischal Acharya, Roberto De Propris, Jari Kotilainen, Ivan K. Baldry, Sarah Brough, Simon P. Driver, Alister W. Graham, Benne Holwerda, Andrew M. Hopkins, Angel R. López-Sánchez, Jonathan Loveday, Steven Phillipps, Kevin A. Pimbblet, Edward Taylor, Lingyu Wang, Angus H. Wright Apr 2022

Galaxy And Mass Assembly (Gama): The Weak Environmental Dependence Of Quasar Activity At 0.1 < Z < 0.35, Clare F. Wethers, Nischal Acharya, Roberto De Propris, Jari Kotilainen, Ivan K. Baldry, Sarah Brough, Simon P. Driver, Alister W. Graham, Benne Holwerda, Andrew M. Hopkins, Angel R. López-Sánchez, Jonathan Loveday, Steven Phillipps, Kevin A. Pimbblet, Edward Taylor, Lingyu Wang, Angus H. Wright

Faculty and Staff Scholarship

Understanding the connection between nuclear activity and galaxy environment remains critical in constraining models of galaxy evolution. By exploiting the extensive cataloged data from the Galaxy and Mass Assembly survey, we identify a representative sample of 205 quasars at 0.1 < z < 0.35 and establish a comparison sample of galaxies, closely matched to the quasar sample in terms of both stellar mass and redshift. On scales <1 Mpc, the galaxy number counts and group membership of quasars appear entirely consistent with those of the matched galaxy sample. Despite this, we find that quasars are ∼1.5 times more likely to be classified as the group center, indicating a potential link between quasar activity and cold gas flows or galaxy interactions associated with rich group environments. On scales of ∼a few Mpc, the clustering strengths of both samples are statistically consistent, and beyond 10 Mpc, we find no evidence that quasars trace large-scale structures any more than the galaxy control sample. Both populations are found to prefer intermediate-density sheets and filaments to either very high-density environments or very low-density environments. This weak dependence of quasar activity on galaxy environment supports a paradigm in which quasars represent a phase in the lifetime of all massive galaxies and in which secular processes and a group-centric location are the dominant triggers of quasars at low redshift.

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Prefusion Spike Protein Conformational Changes Are Slower In Sars-Cov-2 Than In Sars-Cov-1, Vivek Govind Kumar, Dylan S. Ogden, Ugochi H. Isu, Adithya Polasa, James Losey, Mahmoud Moradi Apr 2022

Prefusion Spike Protein Conformational Changes Are Slower In Sars-Cov-2 Than In Sars-Cov-1, Vivek Govind Kumar, Dylan S. Ogden, Ugochi H. Isu, Adithya Polasa, James Losey, Mahmoud Moradi

Chemistry & Biochemistry Faculty Publications and Presentations

Within the last 2 decades, severe acute respiratory syndrome coronaviruses 1 and 2 (SARS-CoV-1 and SARS-CoV-2) have caused two major outbreaks; yet, for reasons not fully understood, the coronavirus disease 2019 pandemic caused by SARS-CoV-2 has been significantly more widespread than the 2003 SARS epidemic caused by SARS-CoV-1, despite striking similarities between these two viruses. The SARS-CoV-1 and SARSCoV-2 spike proteins, both of which bind to host cell angiotensin-converting enzyme 2, have been implied to be a potential source of their differential transmissibility. However, the mechanistic details of prefusion spike protein binding to angiotensin-converting enzyme 2 remain elusive at the …

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Metal Free Bond Activation By Carboranyl Phosphines, Gayathri B. Gange Apr 2022

Metal Free Bond Activation By Carboranyl Phosphines, Gayathri B. Gange

Theses and Dissertations

In the past few decades, main group-based catalysts have attracted increasing attention as an alternative approach to overcome the most prevailing issues of transition metal catalysts such as high cost, toxicity, and low abundance. Among these main groupbased catalysts, Phosphine based compounds have shown a variety of bond activations due to the strong nucleophilicity from their congener species. To the contrary, unique electron deficient boron-based clusters have the tendency to accept two electrons reversibly due to their electron deficiency. In this study, we have synchronized the electron donor ability of the phosphine with the electron acceptor ability of the ortho …

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Synthesis Of Carborane Pincer Complexes And Exploration Of The Reactivity Of Metal-Boron Bonds, Hindurangalage Don Asela Chathumal Jayaweera Apr 2022

Synthesis Of Carborane Pincer Complexes And Exploration Of The Reactivity Of Metal-Boron Bonds, Hindurangalage Don Asela Chathumal Jayaweera

Theses and Dissertations

Exploration of transition metal complexes with metal-boron bonds for the cooperative bond activation of small molecules in catalysis is one of the recent developments in novel synthetic strategies. The use of boron clusters as a modular platform for the formation of metal-boron bond has been successfully utilized by our and other groups. Carboranes are icosahedral boron-carbon molecular clusters that have gained attraction as multifunctional ligands due to their unique geometry, electronic properties, and versatility of functionalization methods. Their 3-D structure exerts a steric bulk around the exohedral substituent, either metal or non-metal center. Furthermore, due to the cluster geometry, five …

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Photophysics And Electronic Properties Of Photochromic Metal-Organic Frameworks, Corey R. Martin Apr 2022

Photophysics And Electronic Properties Of Photochromic Metal-Organic Frameworks, Corey R. Martin

Theses and Dissertations

Modulation of materials properties through light-based illumination has the capability to expand the technology sector due to stimuli-responsive dynamic behavior that cannot be achieved in traditional materials. For example, reversibly tuning photophysical profiles of such materials allows for switching between discrete states that is a key aspect for the developing logic gates, spatially- and temporally-resolved sensors, and on-demand drug delivery systems. My efforts have focused on employment of metal-organic frameworks (MOFs) as a versatile platform for the material development which contain photochromic moieties allowing for tailoring their electronic properties. Our group has expanded this direction to include heterometallic and actinide-containing …

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Automata-Theoretic Approaches To Planning In Robotics: Combinatorial Filter Minimization, Planning To Chronicle, Temporal Logic Planning With Soft Specifications, And Sensor Selection For Detecting Deviations From A Planned Itinerary, Hazhar Rahmani Apr 2022

Automata-Theoretic Approaches To Planning In Robotics: Combinatorial Filter Minimization, Planning To Chronicle, Temporal Logic Planning With Soft Specifications, And Sensor Selection For Detecting Deviations From A Planned Itinerary, Hazhar Rahmani

Theses and Dissertations

In this dissertation, we present a collection of new planning algorithms that enable robots to achieve complex goals, beyond simple point-to-point path planning, using automata-theoretic methods, and we consider the filter minimization (FM) problem and a variant of it, filter partitioning minimization (FPM) problem, which aims to minimize combinatorial filters, used for filtering and automata-theoretic planning in systems with discrete sensor data. We introduce a new variant of bisimulation, compatibility, and using this notion we identify several classes of filters for which FM or FPM is solvable in polynomial time, and propose several integer linear programming (ILP) formulations …

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Tangled Up In Tanglegrams, Drew Joseph Scalzo Apr 2022

Tangled Up In Tanglegrams, Drew Joseph Scalzo

Theses and Dissertations

Tanglegrams are graphs consisting of two rooted binary plane trees with the same number of leaves and a perfect matching between the two leaf sets. A Tanglegram drawing is a special way of drawing a Tanglegram; and a Tanglegram is called planar if it has a drawing such that the matching edges do not cross. In this thesis, we will discuss various results related to the construction and planarity of Tanglegrams, as well as demonstrate how to construct all the Tanglegrams of size 4 by looking at two types of rooted binary trees - Caterpillar and Complete Binary Trees. After …

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Tailored Nanomaterials For Advancing Fast-Charge Research, Wessel Van Den Bergh Apr 2022

Tailored Nanomaterials For Advancing Fast-Charge Research, Wessel Van Den Bergh

Theses and Dissertations

The demand for fast, energy-dense storage has driven research into nanoscale intercalation materials. Nanoscale materials not only accelerate kinetics but also can modify reaction path thermodynamics, intercalant solubility, and diffusivity. Pioneering works have revealed such nanoscale changes, often without the need to separately probe each fundamental transport process. While electrodes can be designed to have one transport processes dominant, there remain opportunities to better understand energy-dense designs with multiple concomitant transport constraints. The contents herein highlight emerging an method using tailored, energy-dense nanomaterials and the process of elimination to clearly correlate architectural features to performance. For example, this method revealed …

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Whistler Waves: Modeling And Observations, Daniel Williams Apr 2022

Whistler Waves: Modeling And Observations, Daniel Williams

Doctoral Dissertations and Master's Theses

The thesis presents the results of all the research from the published and in publication process research in the Journal of Geophysical Research [1]. This research focuses on whistler wave ducting events in the equatorial magnetosphere. High-density ducts are the main focus of whistler study in both studies as they are commonly observed by the Van Allen Probe satellites. A three-step procedure based on the analysis of the whistler wave dispersion relation and numerical simulations of the electron magnetohydrodynamics model. We use this model to identify the parallel and perpendicular wave numbers of the “most trapped” wave in an attempt …

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Design And Development Of Distributed Lower Atmospheric Instrumentation Packages, Julio Guardado Apr 2022

Design And Development Of Distributed Lower Atmospheric Instrumentation Packages, Julio Guardado

Doctoral Dissertations and Master's Theses

The recent miniaturization of embedded electronics and widespread availability of low-cost sensors, microcontrollers and transceivers has enabled development of sensor suites that can be used for high temporal and spatial resolution measurements of atmospheric parameters such as temperature, pressure, humidity, particulate counts, wind velocity and much more. This thesis presents the development of both airborne and ground based distributed atmospheric instrumentation suites. First, we present a low-cost radiosonde platform capable of simultaneous multipoint launches or high cadence back-to-back continuous launches. This radiosonde platform can do wind measurements on an approximately 60 m scale up to a minimum of 25 km. …

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Search For An Axionlike Particle In B Meson Decays, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu. G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, Milind Purohit, Jeffrey R. Wilson, Et. Al. Apr 2022

Search For An Axionlike Particle In B Meson Decays, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu. G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, R. Cheaib, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, Milind Purohit, Jeffrey R. Wilson, Et. Al.

Faculty Publications

Axionlike particles (ALPs) are predicted in many extensions of the standard model, and their masses can naturally be well below the electroweak scale. In the presence of couplings to electroweak bosons, these particles could be emitted in flavor-changing B meson decays. We report herein a search for an ALP, a, in the reaction B ±→K ± a, a →γ γ using data collected by the BABAR experiment at SLAC. No significant signal is observed, and 90% confidence level upper limits on the ALP coupling to electroweak bosons are derived as a function of ALP mass, improving current …

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Covering Systems And The Minimum Modulus Problem, Maria Claire Cummings Apr 2022

Covering Systems And The Minimum Modulus Problem, Maria Claire Cummings

Theses and Dissertations

A covering system or a covering is a set of linear congruences such that every integer satisfies at least one of these congruences. In 1950, Erdős posed a problem regarding the existence of a finite covering with distinct moduli and an arbitrarily large minimum modulus. This remained unanswered until 2015 when Robert Hough proved an explicit bound of 1016 for the minimum modulus of any such covering. In this thesis, we examine the use of covering systems in number theory results, expand upon the proof of the existence of an upper bound on the minimum modulus in the case of …

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Molecular Cloud Properties In High-Mass Star Forming Regions, Mohammed Essa Abdulla Ali Ahli Apr 2022

Molecular Cloud Properties In High-Mass Star Forming Regions, Mohammed Essa Abdulla Ali Ahli

Theses

Using high spatial resolution observation of 12CO (2−1) and 13CO (2−1) emissions, I present the molecular cloud properties of N42 in the Small Magellanic Cloud. The observations were taken using the Atacama Large Millimeter Array observations. I conducted a thorough analysis of molecular gas properties to understand how the cloud properties of N42 differ from those of Galactic clouds. My analysis shows that, in N42, the majority of CO emission appears clumpy, while molecular cores with YSOs exhibit greater linewidths and masses. Massive clump cores are associated with YSOs. Virial analysis of the 12CO and 13CO …

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