Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Computer Sciences (4468)
- Earth Sciences (3274)
- Engineering (3242)
- Life Sciences (3192)
- Environmental Sciences (2195)
-
- Computer Engineering (1982)
- Artificial Intelligence and Robotics (1916)
- Soil Science (1906)
- Plant Sciences (1900)
- Numerical Analysis and Scientific Computing (1604)
- Operations Research, Systems Engineering and Industrial Engineering (1545)
- Chemistry (1544)
- Systems Science (1491)
- Mathematics (1380)
- Physics (1332)
- Social and Behavioral Sciences (954)
- Oceanography and Atmospheric Sciences and Meteorology (739)
- Medicine and Health Sciences (658)
- Statistics and Probability (637)
- Sustainability (599)
- Electrical and Computer Engineering (509)
- Natural Resources and Conservation (507)
- Applied Mathematics (472)
- Geology (441)
- Education (431)
- Natural Resources Management and Policy (427)
- Databases and Information Systems (388)
- Other Environmental Sciences (341)
- Arts and Humanities (331)
- Institution
-
- University of Kentucky (1971)
- China Simulation Federation (1490)
- University of Nebraska - Lincoln (647)
- TÜBİTAK (626)
- Singapore Management University (493)
-
- Old Dominion University (271)
- University of Texas Rio Grande Valley (243)
- City University of New York (CUNY) (241)
- Chulalongkorn University (218)
- China Coal Technology and Engineering Group (CCTEG) (204)
- University of South Florida (203)
- Utah State University (202)
- Portland State University (188)
- University of Texas at El Paso (176)
- Louisiana State University (165)
- Technological University Dublin (159)
- Western University (158)
- Nova Southeastern University (152)
- Missouri University of Science and Technology (150)
- Western Washington University (140)
- University of Nevada, Las Vegas (134)
- William & Mary (127)
- Air Force Institute of Technology (121)
- University of New Mexico (120)
- University of Wollongong (118)
- University of Arkansas, Fayetteville (115)
- Claremont Colleges (113)
- University of Central Florida (113)
- Walden University (107)
- Boise State University (106)
- Keyword
-
- Machine learning (242)
- Climate change (135)
- Deep learning (115)
- Simulation (110)
- Sustainability (98)
-
- Machine Learning (94)
- Grazing (84)
- COVID-19 (76)
- Computer Science (74)
- Mathematics (74)
- Remote sensing (72)
- Cybersecurity (69)
- Artificial intelligence (65)
- Climate (64)
- Physics (62)
- Biodiversity (56)
- Grassland (56)
- Chemistry (55)
- Modeling (50)
- Environment (45)
- Statistics (44)
- Agriculture (42)
- Nitrogen (42)
- Optimization (42)
- Deep Learning (41)
- Classification (40)
- Livestock (39)
- Conservation (38)
- GIS (38)
- Neural networks (38)
- Publication
-
- IGC Proceedings (1993-2023) (1785)
- Journal of System Simulation (1490)
- Theses and Dissertations (494)
- Research Collection School Of Computing and Information Systems (447)
- Turkish Journal of Electrical Engineering and Computer Sciences (230)
-
- Coal Geology & Exploration (204)
- Chulalongkorn University Theses and Dissertations (Chula ETD) (190)
- Faculty Publications (190)
- Electronic Theses and Dissertations (189)
- Turkish Journal of Mathematics (169)
- USF Tampa Graduate Theses and Dissertations (131)
- Turkish Journal of Chemistry (130)
- Dissertations (115)
- Electronic Thesis and Dissertation Repository (114)
- Departmental Technical Reports (CS) (110)
- Articles (107)
- Walden Dissertations and Doctoral Studies (106)
- Australian Institute for Innovative Materials - Papers (104)
- Honors Theses (98)
- School of Natural Resources: Faculty Publications (95)
- Open Educational Resources (91)
- Applications and Applied Mathematics: An International Journal (AAM) (90)
- Electronic Theses and Dissertations, 2020-2023 (88)
- Research outputs 2014 to 2021 (87)
- United States Department of Agriculture Wildlife Services: Staff Publications (85)
- Graduate Theses and Dissertations (83)
- The Synapse: Intercollegiate science magazine (82)
- Journal of Electrochemistry (81)
- Doctoral Dissertations (77)
- Publications and Research (74)
- Publication Type
Articles 15091 - 15120 of 15205
Full-Text Articles in Physical Sciences and Mathematics
Enabling And Threatening Factors Affecting Persistence. A Qualitative And Quantitative Study On Rural First-Generation Stem Students’ And Stem Faculty's Perspectives., Travis A. Miller
Graduate Theses, Dissertations, and Problem Reports
This study focuses on the factors that enable and threaten rural first-generation STEM students’ persistence. Limited empirical studies are available that focus on rural first-generation STEM majors’ persistence. Quantitative analysis was conducted using Kruskal Wallis H and Mann-Whitney U tests to determine any significant differences with the survey results. Content and thematic analysis was conducted on the student and faculty interviews to determine themes of enabling and threatening factors affecting persistence.
Enabling factors affecting persistence were found to be: Drive or Motivation, Experiences and skills, and Support. These were both faculty and student interview themes whereas a …
Family Forest Owners Satisfaction With Timber Transactions, Jeffrey M. Lee
Family Forest Owners Satisfaction With Timber Transactions, Jeffrey M. Lee
Graduate Theses, Dissertations, and Problem Reports
Forest industries in the eastern U.S. rely heavily on family forest owners to supply fiber needs for their mills. As of 2017, 79 percent of West Virginia is classified as forestland and of this roughly 86.5 percent is privately owned. With such a heavy reliance on wood from private forest lands, family forest owner satisfaction is extremely important if companies want to continue harvesting or working with these landowners in the future.
Timber transactions are complex. No two timber transactions are exactly the same. They often involve many different parties apart from the landowner. Site conditions, land cover, and landowner …
Modeling The Galactic Compact Binary Neutron Star Population And Studying The Double Pulsar System, Nihan Pol
Modeling The Galactic Compact Binary Neutron Star Population And Studying The Double Pulsar System, Nihan Pol
Graduate Theses, Dissertations, and Problem Reports
Binary neutron star (BNS) systems consisting of at least one neutron star provide an avenue for testing a broad range of physical phenomena ranging from tests of General Relativity to probing magnetospheric physics to understanding the behavior of matter in the densest environments in the Universe. Ultra-compact BNS systems with orbital periods less than few tens of minutes emit gravitational waves with frequencies ~mHz and are detectable by the planned space-based Laser Interferometer Space Antenna (LISA), while merging BNS systems produce a chirping gravitational wave signal that can be detected by the ground-based Laser Interferometer Gravitational-Wave Observatory (LIGO). Thus, BNS …
Estimating Refactoring Efforts For Architecture Technical Debt, Samir Deeb
Estimating Refactoring Efforts For Architecture Technical Debt, Samir Deeb
Graduate Theses, Dissertations, and Problem Reports
Paying-off the Architectural Technical Debt by refactoring the flawed code is important to control the debt and to keep it as low as possible. Project Managers tend to delay paying off this debt because they face difficulties in comparing the cost of the refactoring against the benefits they gain. For these managers to decide whether to refactor or to postpone, they need to estimate the cost and the efforts required to conduct these refactoring activities as well as to decide which flaws have higher priority to be refactored among others.
Our research is based on a dataset used by other …
A Machine Learning And Data-Driven Prediction And Inversion Of Reservoir Brittleness From Geophysical Logs And Seismic Signals: A Case Study In Southwest Pennsylvania, Central Appalachian Basin, Tobi Micheal Ore
Graduate Theses, Dissertations, and Problem Reports
In unconventional reservoir sweet-spot identification, brittleness is an important parameter that is used as an easiness measure of production from low permeability reservoirs. In shaly reservoirs, production is realized from hydraulic fracturing, which depends on how brittle the rock is–as it opens natural fractures and also creates new fractures. A measure of brittleness, brittleness index, is obtained through elastic properties of the rock. In practice, problems arise using this method to predict brittleness because of the limited availability of elastic logs.
To address this issue, machine learning techniques are adopted to predict brittleness at well locations from readily available geophysical …
Physical And Chemical Properties Of Clastic Sediments From Two Caves In The Northern Karst Region Of Puerto Rico, Autum R. Downey
Physical And Chemical Properties Of Clastic Sediments From Two Caves In The Northern Karst Region Of Puerto Rico, Autum R. Downey
Graduate Theses, Dissertations, and Problem Reports
Geochemical properties and organic characteristics are essential to understanding the general depositional dynamics of a cave. Most work on clastic cave sediments focuses on physical properties of sediments. Little work has been done on bulk organic matter and geochemical properties.
This project reports physical and geochemical characterization of cave sediments from two caves in the northern karst region of Puerto Rico: El Tallonal Cave and Cueva Clara. Core and grab samples were collected and analyzed for particle size, total organic carbon, total nitrogen, organic matter characteristics using fluorescence spectroscopy, and major and minor elements using X-ray fluorescence (XRF). The sediments …
Theory And Techniques Of Convergence Of Topological Transformation Group Actions, Murtadha Jaber Sarray
Theory And Techniques Of Convergence Of Topological Transformation Group Actions, Murtadha Jaber Sarray
Graduate Theses, Dissertations, and Problem Reports
n this dissertation, we present new set functions called strongly limit and strongly prolongation limit sets. We show the new sets, especially strongly prolongation limit sets, characterize proper action under an arbitrary setting. That is, we characterize proper action for wider class of proper ܩ-spaces. Also, we show the new version of the sets could be derived from strongly exceptional sets which have been used as a good technique for the characterization of a proper maps. Moreover, we review properties of well-known limit sets and prolongations and properties for the new version of limit sets under an arbitrary setting on …
Searching For Needles In The Cosmic Haystack, Thomas Ryan Devine
Searching For Needles In The Cosmic Haystack, Thomas Ryan Devine
Graduate Theses, Dissertations, and Problem Reports
Searching for pulsar signals in radio astronomy data sets is a difficult task. The data sets are extremely large, approaching the petabyte scale, and are growing larger as instruments become more advanced. Big Data brings with it big challenges. Processing the data to identify candidate pulsar signals is computationally expensive and must utilize parallelism to be scalable. Labeling benchmarks for supervised classification is costly. To compound the problem, pulsar signals are very rare, e.g., only 0.05% of the instances in one data set represent pulsars. Furthermore, there are many different approaches to candidate classification with no consensus on a best …
On Demand Nanoscale Phase Manipulation Of Vanadium Dioxide By Scanning Probe Lithography, Dustin Schrecongost
On Demand Nanoscale Phase Manipulation Of Vanadium Dioxide By Scanning Probe Lithography, Dustin Schrecongost
Graduate Theses, Dissertations, and Problem Reports
This dissertation focuses on nanoscale phase manipulations of Vanadium Dioxide. Nanoscale control of material properties is a current obstacle for the next generation of optoelectronic and photonic devices. Vanadium Dioxide is a strongly correlated material with an insulator-metal phase transition at approximately 345 K that generates dramatic electronic and optical property changes. However, the development of industry device application based on this phenomenon has been limited thus far due to the macroscopic scale and the volatile nature of the phase transition. In this work these limitations are assessed and circumvented.
A home-built, variable temperature, scanning near-field optical microscope was engineered …
Habitat Stability In Appalachian Headwater Systems And Potential Impacts On Brook Trout Populations, Zac F.W Zacavish
Habitat Stability In Appalachian Headwater Systems And Potential Impacts On Brook Trout Populations, Zac F.W Zacavish
Graduate Theses, Dissertations, and Problem Reports
The impact climate change will have on the habitat for Brook Trout (Salvelinus fontinalis) could directly impact key demographic characteristics. Traditionally, broad-scale studies of climate change effects on the family Salmonidae focus on the thermal shifts predicted over the next century. While some studies shed light onto other variables such as biotic interactions, flow regime, and disturbance, the significance of the climate-trout interaction is not always observed. With the high degree of influence climate cycles can have on habitat and channel morphology, this study aimed to highlight temporal habitat shifts to begin addressing climate-habitat interaction. By studying habitat distribution …
Weighted Modulo Orientations Of Graphs, Jianbing Liu
Weighted Modulo Orientations Of Graphs, Jianbing Liu
Graduate Theses, Dissertations, and Problem Reports
This dissertation focuses on the subject of nowhere-zero flow problems on graphs. Tutte's 5-Flow Conjecture (1954) states that every bridgeless graph admits a nowhere-zero 5-flow, and Tutte's 3-Flow Conjecture (1972) states that every 4-edge-connected graph admits a nowhere-zero 3-flow. Extending Tutte's flows conjectures, Jaeger's Circular Flow Conjecture (1981) says every 4k-edge-connected graph admits a modulo (2k+1)-orientation, that is, an orientation such that the indegree is congruent to outdegree modulo (2k+1) at every vertex. Note that the k=1 case of Circular Flow Conjecture coincides with the 3-Flow Conjecture, and the case of k=2 implies the 5-Flow Conjecture. This work is devoted …
Investigating Effects Of Carbonate Minerals On Shale- Hydraulic Fracturing Fluid Interactions In The Marcellus Shale, Brennan Matthew Ferguson
Investigating Effects Of Carbonate Minerals On Shale- Hydraulic Fracturing Fluid Interactions In The Marcellus Shale, Brennan Matthew Ferguson
Graduate Theses, Dissertations, and Problem Reports
Natural gas extracted from tight shale formations, such as the Marcellus Shale, represent an important and developing front in energy exploration. By fracturing these formations using pressurized fracturing fluid, previously unobtainable hydrocarbon reserves may be tapped. While pursuing this resource hydraulic fracturing operations leave chemically complex fluids in the shale formation for at least two weeks. This provides a substantial opportunity for the hydraulic fracturing fluid (HFF) to react with the shale formation at reservoir temperature and pressure. In this study, we investigated the effects of the carbonates on shale-HFF reactions with a focus on the Marcellus Shale. We determined …
Three Essays On Health Economics And Policy Evaluation, Shishir Shakya
Three Essays On Health Economics And Policy Evaluation, Shishir Shakya
Graduate Theses, Dissertations, and Problem Reports
This dissertation consists of three essays on the U.S. Health care policy. Each paragraph below refers to the three abstracts for the three chapters in this dissertation, respectively. I provide quantitative evidence on how much Prescription Drug Monitoring Programs (PDMPs) affects the retail opioid prescribing behaviors. Using the American Community Survey (ACS), I retrieve county-level high dimensional panel data set from 2010 to 2017. I employ three separate identification strategies: difference-in-difference, double selection post-LASSO, and spatial difference-in-difference. I compare how the retail opioid prescribing behaviors of counties, that are mandatory for prescribers to check the PDMP before prescribing controlled substances …
Relating Recharge Mechanisms To Chemical Changes In An Updip Appalachian Coal Mine Discharge: A Case Study From Lambert Run, West Virginia, Matthew Lewis Bell
Relating Recharge Mechanisms To Chemical Changes In An Updip Appalachian Coal Mine Discharge: A Case Study From Lambert Run, West Virginia, Matthew Lewis Bell
Graduate Theses, Dissertations, and Problem Reports
Impaired drainage from active and abandoned mines degrades the water quality of receiving streams and aquifers. Coal mine drainage (CMD) has been studied for decades in Appalachia, but unknowns and uncertainties are still present, including the influence of mine hydrogeology on the outflow chemistry of above-drainage mines. To evaluate the influence of recharge type on above-drainage mine chemistry, samples were collected every two weeks at a CMD outflow treatment system in Harrison County, West Virginia.
Samples were collected to measure geochemical changes taking place in the mine workings and along the flowpath of the passive treatment system. Samples were divided …
Evolution Of Extreme Continental Saline Environments: A Sedimentological Investigation Of Permo-Triassic Redbeds And Evaporites In Northern Ireland And Kansas, Anna Sofia S. Andeskie
Evolution Of Extreme Continental Saline Environments: A Sedimentological Investigation Of Permo-Triassic Redbeds And Evaporites In Northern Ireland And Kansas, Anna Sofia S. Andeskie
Graduate Theses, Dissertations, and Problem Reports
The Permo-Triassic was a time of extreme environments, unusually warm and arid climates, and biotic crises. This study investigates Pangean environments and climate leading to extreme acid saline lake systems represented by the Permian Nippewalla Group of Kansas and the Triassic Mercia Mudstone Group of Northern Ireland. Sedimentological observations of the underlying rocks, the Permian Hutchinson Salt Member of Kansas and the Permian Belfast Harbour Evaporite Formation of Northern Ireland, help to understand trends in environmental and climatic conditions leading to these extreme environments. This dissertation also refines the geographic extent of extreme acid saline lake and groundwater systems through …
Representation Learning With Adversarial Latent Autoencoders, Stanislav Pidhorskyi M.S.
Representation Learning With Adversarial Latent Autoencoders, Stanislav Pidhorskyi M.S.
Graduate Theses, Dissertations, and Problem Reports
A large number of deep learning methods applied to computer vision problems require encoder-decoder maps. These methods include, but are not limited to, self-representation learning, generalization, few-shot learning, and novelty detection. Encoder-decoder maps are also useful for photo manipulation, photo editing, superresolution, etc. Encoder-decoder maps are typically learned using autoencoder networks.
Traditionally, autoencoder reciprocity is achieved in the image-space using pixel-wise
similarity loss, which has a widely known flaw of producing non-realistic reconstructions. This flaw is typical for the Variational Autoencoder (VAE) family and is not only limited to pixel-wise similarity losses, but is common to all methods relying upon …
Image And Video-Based Autism Spectrum Disorder Detection Via Deep Learning, Mindi Ruan
Image And Video-Based Autism Spectrum Disorder Detection Via Deep Learning, Mindi Ruan
Graduate Theses, Dissertations, and Problem Reports
People with Autism Spectrum Disorder (ASD) show atypical attention to social stimuli and aberrant gaze when viewing images of the physical world. However, it is unknown how they perceive the world from a first-person perspective. In this study, we used machine learning to classify photos taken in three different categories (people, indoors, and outdoors) as either having been taken by individuals with ASD or by peers without ASD. Our classifier effectively discriminated photos from all three categories but was particularly successful at classifying photos of people with >80% accuracy. Importantly, the visualization of our model revealed critical features that led …
Capillary Electrophoresis Analysis Of Proteins Using Phospholipid Based Materials, Cassandra L. Crihfield
Capillary Electrophoresis Analysis Of Proteins Using Phospholipid Based Materials, Cassandra L. Crihfield
Graduate Theses, Dissertations, and Problem Reports
Capillary electrophoresis has many advantages that make it a powerful technique for the analysis of proteins, which is challenging due to the natural heterogeneity of proteins. The small sample volume required for each analysis (nano- and pico-liter), fast separation times (<30 >min), and ability to couple the separation to mass spectrometry are all factors that make capillary electrophoresis an ideal technology for protein separations. Capillary zone electrophoresis and capillary gel electrophoresis are the two most commonly employed modes for protein analysis and allow for rapid, high resolution separations that can be automated. This makes capillary electrophoresis ideal for meeting the …30>
Searches For Fast Radio Bursts Using Machine Learning, Devansh Agarwal
Searches For Fast Radio Bursts Using Machine Learning, Devansh Agarwal
Graduate Theses, Dissertations, and Problem Reports
Fast Radio bursts (FRBs) are enigmatic astrophysical events with millisecond durations and flux densities in the range 0.1-100 Jy, with the prototype source discovered by Lorimer et al. (2007). Like pulsars, FRBs show the characteristic inverse square sweep in observing frequency due to propagation through an ionized medium. This effect is quantified by the dispersion measure (DM). Unlike pulsars, FRBs have anomalously high DMs, which are consistent with an extragalactic origin. Over 100 FRBs have been published at the time of writing, and 13 have been conclusively identified with host galaxies with spectroscopically determined redshifts in the range 0.003 ≤ …
Development And Implementation Of A Novel Voltage-Free Interface For Capillary Electrophoresis-Mass Spectrometry Separations Of Proteins, Courtney J. Kristoff
Development And Implementation Of A Novel Voltage-Free Interface For Capillary Electrophoresis-Mass Spectrometry Separations Of Proteins, Courtney J. Kristoff
Graduate Theses, Dissertations, and Problem Reports
Capillary electrophoresis-mass spectrometry is a powerful technique for high-throughput and high efficiency separations combined with structural identification. Electrospray ionization is the primary interface used to couple capillary electrophoresis to mass analyzers; however, improved designs continue to be reported. A new interfacing method based on vibrating sharp-edge spray ionization is presented in this work to overcome the challenges of decoupling applied voltages and to enhance the compatibility with separations performed at near-neutral pH. The versatility and ease of use of this ionization source is demonstrated using β-blockers, peptides, and proteins. The cationic β-blocker pindolol was injected electrokinetically and detected at concentrations …
A Machine Learning Approach To Estimate The Annihilation Photon Interactions Inside The Scintillator Of A Pet Scanner, Sai Akhil Bharthavarapu
A Machine Learning Approach To Estimate The Annihilation Photon Interactions Inside The Scintillator Of A Pet Scanner, Sai Akhil Bharthavarapu
Graduate Theses, Dissertations, and Problem Reports
Biochemical processes are chemical processes that occur in living organisms. They can be studied with nuclear medicine through the help of radioactive tracers. Based on the radioisotope used, the photons that are emitted from the body tissue are either detected by single-photon emission computed tomography (SPECT) or by positron emission tomography (PET) scanners. SPECT uses gamma rays as tracer but gives a weaker contrast and spatial resolution compared to a PET scanner which uses positrons as tracer. PET scans show the metabolic changes occurring at the cellular level in an organ or a tissue. This detection is important because diseases …
Paleoecological Successions From Shallow-Marine Depositional Environments In Upper Silurian Carbonate Rocks Of Blair County, Pennsylvania, Shadya El-Ashkar
Paleoecological Successions From Shallow-Marine Depositional Environments In Upper Silurian Carbonate Rocks Of Blair County, Pennsylvania, Shadya El-Ashkar
Graduate Theses, Dissertations, and Problem Reports
Studies of paleoenvironment and paleoecology are important for investigating relationships between the different environmental and biological variables that influenced biodiversification patterns during the Silurian Period. The mixed carbonate and siliciclastic rocks of the Bloomsburg and Mifflintown Formations in central Pennsylvania represent transitions between carbonate ramp and deltaic settings. The goal of this study was to assess changes in depositional environment and paleoecology of an undescribed Bloomsburg/Mifflintown locality in Bellwood, Pennsylvania. In central Pennsylvania, the interfingered relationship of mixed carbonate and siliciclastic mudstones of the Mifflintown Formation with red fine-grained sandstones and shales of the Bloomsburg Formation presented challenges for deciphering …
Experimental And Computational Exploration Of The Dilute Magnetic Delafossite Cual1-Xfexo2 Alloys, Mina Aziziha
Experimental And Computational Exploration Of The Dilute Magnetic Delafossite Cual1-Xfexo2 Alloys, Mina Aziziha
Graduate Theses, Dissertations, and Problem Reports
CuAlO2 is among several ternary delafossites, which is a rare p-type semiconductor with potential applications as a transparent conductive oxide, photocatalyst, and spintronics when doped with transition metal ions. Reported in this thesis are results from our investigations of CuAl1-xFexO2 (x = 0 to1) with a focus on the x-dependence of structural, magnetic, vibrational, optical properties, and the role of defects and impurities. Samples are prepared by solid-state reactions.
We performed a complete study of magnetic properties to investigate the possibility of room temperature ferromagnetic alloys, which are used in …
Cobalt-Catalyzed Aerobic Oxidative Cyclization Reactions Of Bisnucleophiles: New Methodologies And The Role Of Bisnucleophiles In O2 Activation, Jiaqi Liu
Graduate Theses, Dissertations, and Problem Reports
Over the past few decades, transition metals have found wide applications in the development of selective oxidative transformations mediated by molecular oxygen. Due to the benign nature of molecular oxygen as an oxidant and an increasing awareness of green chemistry practice, tremendous progress has been made towards the development of Cu-and Pd-catalyzed aerobic oxidation reactions. As a first-row transition metal alternative to copper, cobalt has been employed in aerobic catalytic transformations for its cost-efficiency and earth abundance; however, redox-active mediators such as benzoquinone (BQ), N-hydroxyphthalimide (NHPI) or salen-type ligands are usually required. To date, reactions mediated by Co/O2 catalytic …
Factors Influencing Huntingtin Aggregation At Surfaces: Implications For Huntington’S Disease, Sharon E. Groover
Factors Influencing Huntingtin Aggregation At Surfaces: Implications For Huntington’S Disease, Sharon E. Groover
Graduate Theses, Dissertations, and Problem Reports
Huntington’s Disease (HD) is a genetic, neurodegenerative disease characterized by an abnormal polyglutamine (polyQ) expansion in the first exon of the huntingtin protein (htt). The polyQ domain facilitates aggregation and initiates the formation of a diverse collection of aggregate species, including fibrils, oligomers and annular aggregates. The first 17 amino acids of htt (Nt17) directly flank the polyQ domain and is a key factor in htt’s association to membranous structures. In addition to Nt17 being an amphipathic αhelix, it also promotes aggregation through self-association and contains numerous posttranslational modifications (PTMs) that can modulate toxicity and subcellular localization. For in depth …
Synthesis And Characterization Of Pyridine Dipyrrolide Iron Complexes Relevant To Nitrene And Carbene Group Transfer, Brett M. Hakey
Synthesis And Characterization Of Pyridine Dipyrrolide Iron Complexes Relevant To Nitrene And Carbene Group Transfer, Brett M. Hakey
Graduate Theses, Dissertations, and Problem Reports
The synthesis and electronic structures of the square-planar high-spin FeII complexes (MesPDPPh)Fe(OEt2) and (MesPDPPh)Fe(thf) were investigated. Analysis of these compounds using a combination of 1H NMR and 57Fe Mössbauer spectroscopies, in conjunction with computational analysis, has resulted in a rationalization for their unusual electronic structures, which arise from the unique coordination environment enforced by the pyridine dipyrrolide chelate ligand.
The reactivity of (MesPDPPh)Fe(thf) with organic azides has been probed and resulted in the isolation of an array of products that are consistent with …
Silver-Mediated Decarboxylation Reactions: Expanding Reaction Scope Through Kinetic Analysis, Robert Anthony Crovak
Silver-Mediated Decarboxylation Reactions: Expanding Reaction Scope Through Kinetic Analysis, Robert Anthony Crovak
Graduate Theses, Dissertations, and Problem Reports
Transition metal-catalyzed decarboxylative coupling reactions have received considerable attention in recent years as a method to obtain biaryl compounds. However, the oxidative version of this reaction class is still in its infancy, limited to specific substitution patterns on the benzoic acids – ortho-substitution - used in these transformations. This thesis describes our attempts to understand the key decarboxylation step of this important class of reactions. The first chapter of this thesis discusses an introduction into cross-coupling reactions, decarboxylative cross-coupling reactions, and outlines relevant physical organic parameters. The following chapter details the synthesis of a series of (1,10-phenanthroline)silver(benzoate) complexes. This chapter …
Mechanistic Analysis Of Reductive Boracarboxylation Using Low Valent Copper And Co2, Notashia Nicole Baughman
Mechanistic Analysis Of Reductive Boracarboxylation Using Low Valent Copper And Co2, Notashia Nicole Baughman
Graduate Theses, Dissertations, and Problem Reports
The synthesis of organoboron compounds is of contemporary importance in the chemistry community given their utility in subsequent functionalization reactions as well as their growing therapeutic potential in the treatment of human disease. This, coupled with the ubiquity of carboxylic acid functional groups in pharmaceuticals and fine chemicals, has led to interest in one-pot difunctionalization reactions using CO2 and a boron source. An (ICy)copper(I)-catalyzed boracarboxylation reaction was recently developed wherein CO2 and a pinacolboryl group is added across the double bond of vinyl arenes was recently developed, providing access to α-aryl-β-boryl propionic acid derivatives. A subsequent publication detailed …
Alluvial Fans, Loess Plains, Lakes, And Distributive Fluvial Systems: Depositional Systems Of The Permian-Triassic Red Beds And Evaporites Of Wyoming (Usa), Jonathan Knapp
Graduate Theses, Dissertations, and Problem Reports
The end-Permian ecological crisis was a period of warming and aridity reaching extreme levels by the end Permian and not recovering before the Middle Triassic. The Permian Goose Egg Formation and the Chugwater Group’s Early Triassic Red Peak Formation and Middle Triassic Alcova Limestone are a continuous or nearly continuous succession of rocks deposited during this warm, arid time in Wyoming. Comprised of red beds, evaporites, and rare carbonates, these rocks have not been subjected to detailed sedimentological investigations in the modern era. Previous interpretations of marine and marginal marine deposition have largely been based on the laterally extensive nature …
Evaluating The Accuracy Of Firearm Examiner Conclusions Using Cartridge Case Reproductions, Eric Freeman Law
Evaluating The Accuracy Of Firearm Examiner Conclusions Using Cartridge Case Reproductions, Eric Freeman Law
Graduate Theses, Dissertations, and Problem Reports
The forensic science pattern comparison areas, including fingerprints, footwear, and firearms, have been criticized for their subjective nature. While much research has attempted to move these disciplines to more objective methods, a majority of examiners are still coming to conclusions based on their own training and experience. To compare accuracy between examiners, a method called double-casting was used in this study to create plastic cartridge case reproductions. In the first part of this study, double-cast accuracy was evaluated using two automated comparison systems to quantify the similarity. It was determined that the double-casting method used here produces accurate reproductions with …