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Articles 1 - 30 of 416
Full-Text Articles in Physical Sciences and Mathematics
Development Of Stochastic And Time-Dependent Quantum Chemical Methods For Accurate Description Of Light-Matter Interactions With Applications In Photoionization And Inverse Photoemission In Nanomaterials, Nicole Spanedda
Dissertations - ALL
There are three main focuses of this work. First, the theoretical details of the Stratified Stochastic Enumeration of Molecular Orbitals (SSE-MO) method is presented, along with its application for calculating ionization potentials (IPs) of quantum dots. The SSE-MO method can readily be applied for the purpose of efficiently and accurately calculating ionization potentials, by constructing the frequency-dependent self-energy operator and then subsequently, solving the associated Dyson equation. Constructing the frequency-dependent self-energy operator is challenging because the scaling of the computational cost with respect to system size, becomes prohibitive for large systems, such as quantum dots. This is due to the …
Synthetic Studies On Ship Modulators, Hif-2Α Antagonists, And New Rhodium Carboxylate Catalysts, Angela Pacherille
Synthetic Studies On Ship Modulators, Hif-2Α Antagonists, And New Rhodium Carboxylate Catalysts, Angela Pacherille
Dissertations - ALL
The PI3K pathway is a major cell signaling axis in eukaryotic cells. This pathway employs the second messenger, inositol phospholipid PI(3,4,5)P3, which is responsible for activating Akt and other kinases creating a cascade of signals. The enzyme, SH2-containing inositol-5’-phosphatase (SHIP), plays a key role in this pathway by maintaining the delicate balance of PI(3,4,5)P3. Modulation of SHIP activity through the use of small molecule inhibitors may be utilized for the treatment of certain types of cancer, Alzheimer’s disease, and diabetes. A high-throughput screen identified the small molecule SHIP1 inhibitor, NSC23922, a mixture of 3α- and 3β-aminocholestane. These diastereomers were synthesized …
Cenozoic Extension Of The Lake Tanganyika Rift, East Africa: Structures, Tectonostratigraphy And Paleoenvironmental Reconstruction, Shaidu Shaban
Cenozoic Extension Of The Lake Tanganyika Rift, East Africa: Structures, Tectonostratigraphy And Paleoenvironmental Reconstruction, Shaidu Shaban
Dissertations - ALL
Active continental rifts are ideal sites for understanding the break-up of continents, and long-lived rift lake environments are known as important reservoirs for endemic communities and biodiversity. The sedimentary fill of extensional continental rifts within the East Africa Rift System (EARS) records a long history of continental extension and variable tropical climate that is unparalleled in its duration and fidelity. Continental extensional basins are sensitive to variations caused by the interplay between tectonics, sedimentary processes, and climate change. However, to discern the sedimentary fill history and its related tectonostratigraphy, as well as for reconstructing past climate changes, high-fidelity data such …
Interpretable Network Representations, Shengmin Jin
Interpretable Network Representations, Shengmin Jin
Dissertations - ALL
Networks (or interchangeably graphs) have been ubiquitous across the globe and within science and engineering: social networks, collaboration networks, protein-protein interaction networks, infrastructure networks, among many others. Machine learning on graphs, especially network representation learning, has shown remarkable performance in network-based applications, such as node/graph classification, graph clustering, and link prediction. Like performance, it is equally crucial for individuals to understand the behavior of machine learning models and be able to explain how these models arrive at a certain decision. Such needs have motivated many studies on interpretability in machine learning. For example, for social network analysis, we may need …
Observation Of The Ξ_B^-→Λ_B^0 Π^- Decay And Measurement Of B(Ξ_B^-→Λ_B^0 Π^-), Zhuoming Li
Observation Of The Ξ_B^-→Λ_B^0 Π^- Decay And Measurement Of B(Ξ_B^-→Λ_B^0 Π^-), Zhuoming Li
Dissertations - ALL
We present the first observation of the weak decay Ξ−b → Λ0b π−, which is mediated by an s → u ̄ud transitionwithin the Ξ_b^- baryon. The analysis uses a pp collision data sample at a center-of-mass energy of 13 TeV corresponding to 5.5 fb^(−1) of integrated luminosity. The sample of Λb0 baryons used in this analysis are reconstructed through their decays to Λ+c π− and Λ+c π−π+π−. From a fit to the Ξ−b → Λ0b π− mass spectrum, the Ξ−b → Λ0b π− decay is observed with a significance of 11.3 standard deviations, thus establishing observation of this decay. …
Testing Detrital Zircon Age Bias In Tectonic Provenance: Examples From Modern Alluvium In The South Island, New Zealand, Will Sparhawk Fisher
Testing Detrital Zircon Age Bias In Tectonic Provenance: Examples From Modern Alluvium In The South Island, New Zealand, Will Sparhawk Fisher
Theses - ALL
Detrital zircon (DZ) grains from 13 drainages across the South Island, New Zealand, were U-Pb dated to ascertain how accurately their ages reflect the geologic record of exposed bedrock. With the proliferation of inexpensive and easily accessible ion microprobes and laser ablation inductively coupled plasma mass spectrometers, DZ dating has become the dominant chronometer for elucidating tectonic systematics. Zircon’s physical and chemical resilience makes it an ideal candidate for U-Pb geochronometry, but is also a potential source of bias. Zircon’s resilience in sedimentary systems means it rarely occurs as first order detritus. N = 966 zircon grains from Modern alluvium …
Heterogeneous Strain Distribution & The Effects Of High Frequency Climate Change On The Evolution Of Early-Stage Rift Systems: Case Studies From Lakes Tanganyika And Malawi (Nyasa), East Africa, Lachlan Wright
Dissertations - ALL
The break-up of the earth’s crust through the formation of continental rift basins is a fundamental aspect of plate-tectonics and the first step that ultimately leads to plate-spreading, new continent formation, and the creation of ocean basins. Within continental rifts, processes associated with extensional faulting drive uplift and subsidence of the landscapes forming rift valleys, and climatically influenced processes act upon these transient landscapes, erode them, modify relief, and produce sediments that infill the rift valleys creating the stratigraphic record. Continental rifts are highly sensitive to the interplay between extensional faulting, sedimentary processes, and climate change, and variations in the …
Algorithmic Solutions To Combat Online Fake News, Xinyi Zhou
Algorithmic Solutions To Combat Online Fake News, Xinyi Zhou
Dissertations - ALL
The unprecedented growth of new information producing, distributing, and consuming every moment on the Web has fostered the rise of ``fake news.'' Because of its detrimental effect on democracy, global economies, and public health, effectively combating online fake news has become an essential and urgent task.
This dissertation starts with making typological, theoretical, and empirical efforts to promote the public's comprehension of fake news and lay the foundation for algorithmically combating fake news. As there has been no universal definition of fake news, this dissertation discusses the definition of fake news from three dimensions: veracity, intention, and news, comparing it …
The Design, Synthesis, And Investigation Into Small Molecule Modulators Of The Src Homology 2 Domain-Containing Inositol 5’-Phosphatase (Ship), Shea Thomas Meyer
The Design, Synthesis, And Investigation Into Small Molecule Modulators Of The Src Homology 2 Domain-Containing Inositol 5’-Phosphatase (Ship), Shea Thomas Meyer
Dissertations - ALL
The PI3K pathway is a major cell signaling pathway that influences survival and longevity in eukaryotic cells. Abnormal signaling of this pathway has been implicated in a number of disorders, including Alzheimer's disease and cancer. The PI3K pathway utilizes the inositolphospholipid PI(3,4,5)P3 as a key secondary messenger in the transmission of signals from outside the cell to the nucleus. The SRC Homology 2 containing Inositol 5’-Phosphatase (SHIP) also plays a key role in the PI3K pathway, mediating hydrolysis of the inositol phospholipid PI(3,4,5)P3 to PI(3,4)P2. Early testing has shown modulation of SHIP activity through the use of small molecule modulators …
High Fidelity Universal Gates Performed On A Continuously-Decoupled Coherence Enhanced Transmon Qubit, Michael Senatore
High Fidelity Universal Gates Performed On A Continuously-Decoupled Coherence Enhanced Transmon Qubit, Michael Senatore
Dissertations - ALL
Decoherence is the primary limiting factor for the utility of modern qubits and qubit networks; most chiefly, pure dephasing which limits the operational time any gate-sequence can produce a high-fidelity result. In this dissertation, I present the results of my experiment, performing fast, high fidelity, universal single-qubit gates, on a qubit which has been decoupled from pure dephasing resulting from environmental noise. This technique can expand operational ranges of qubits–such as allowing the high-coherence operation of a flux-tunable qubit far away from its flux-insensitive sweet-spot; broadening our selection of viable qubits by making otherwise low-coherence qubits operable with high coherence, …
Exploring The Biomedical Applications Of Polyurethane-Based Foams, Films, And Hydrogels, Anand Utpal Vakil
Exploring The Biomedical Applications Of Polyurethane-Based Foams, Films, And Hydrogels, Anand Utpal Vakil
Dissertations - ALL
Shape memory polymers (SMPs) are a class of smart materials that can be temporarily stored in a deformed shape and can actively recover their original shape upon exposure to an external stimulus, such as heat, magnetic field, moisture, pH, light, or electric field. The ability of SMPs to change shape when required can be used for a wide range of applications, especially in the case of minimally invasive biomedical applications. In this work, polyurethane-based SMPs were explored for their use in tissue engineering, drug delivery, and wound healing applications.
In the second chapter, low density porous foams with tunable degradability …
Design And Modeling Of Superconducting Hardware For Implementing Quantum Stabilizers, Yebin Liu
Design And Modeling Of Superconducting Hardware For Implementing Quantum Stabilizers, Yebin Liu
Dissertations - ALL
Superconducting qubits are one of the leading systems for implementing quantum processors. Realizing fault-tolerant quantum computation requires some form of quantum error correction, which typically involves performing repeated stabilizer operations on groups of physical qubits in an array to form a logical qubit with enhanced protection against errors. Realizing a logical qubit that is suitable for running quantum algorithms requires an array with a significant number of physical qubits, which is extremely challenging. However, the physical qubit overhead can be reduced by lowering the error rate on the physical qubits. Current state-of-the-art superconducting qubit designs do not have robust protection …
Characterization Of Superconducting Hardware For Implementing Quantum Stabilizers, Kenneth Richard Dodge
Characterization Of Superconducting Hardware For Implementing Quantum Stabilizers, Kenneth Richard Dodge
Dissertations - ALL
Superconducting qubits are one of the leading approaches being investigated for building a scalable quantum computer. In the presence of external noise and perturbations plus local microscopic fluctuations and dissipation in the qubit environment, arbitrary quantum states will decohere, leading to bit-flip and phase-flip errors of the qubit. In order to build a fault-tolerant quantum computer that can preserve and process quantum information in the presence of noise and dissipation, one must implement some form of quantum error correction. Stabilizer operations are at the heart of quantum error correction and are typically implemented in software-controlled entangling gates and measurements of …
Search For Numi Mudar Electron Neutrinos In Microboone, Ohana Benevides Rodrigues
Search For Numi Mudar Electron Neutrinos In Microboone, Ohana Benevides Rodrigues
Dissertations - ALL
Muon Decay-at-Rest (μDAR) produces electron-neutrinos (νe) in the 0 to 53 MeV energy range. The given range is especially interesting for its similarity to Supernovae-produced νe. The Deep Underground Neutrino Experiment (DUNE) has as one of its main goals to measure Supernovae neutrinos on the occasion of a Galactic Supernova burst. To optimize the chances of detection, a low-energy neutrino-LAr cross-section (XS) measurement is a piece of important information to have at hand. MicroBooNE presents a good opportunity to explore the low-energy ν-LAr detection and XS using the μDAR neutrinos and therefore develop the tools necessary for DUNE to interpret …
Measurements Of B → D(∗)−,0d(∗)+,0k+Π− Branching Fractions In The K∗0 Mass Window, Harris Bernstein
Measurements Of B → D(∗)−,0d(∗)+,0k+Π− Branching Fractions In The K∗0 Mass Window, Harris Bernstein
Dissertations - ALL
This thesis presents measurements of 11 branching fractions of the form B →D(∗)−,0D(∗)+,0K+π− within the K∗0 mass window using LHCb data taken in 2016, 2017 and 2018. All 11 branching fractions are measured simultaneously and are reported alongside the covariance and correlation matrices for the final measurement.
Mechanologic: Designing Mechanical Devices That Compute, Michelle Berry
Mechanologic: Designing Mechanical Devices That Compute, Michelle Berry
Dissertations - ALL
Despite their initial success and impact on the development of the modern computer, mechanical computers were quickly replaced once electronic computers became viable. Recently, there has been increased interest in designing devices that compute using modern and unconventional materials. In this dissertation, we investigate multiple ways to realize a mechanical device that can compute, with a main focus on designing mechanical equivalents for wires and transistors. For our first approach at designing mechanical wires, we present results on the propagation of signals in a soft mechanical wire composed of bistable elements. When we send a signal along bistable wires that …
Protection Against Contagion In Complex Networks, Pegah Hozhabrierdi
Protection Against Contagion In Complex Networks, Pegah Hozhabrierdi
Dissertations - ALL
In real-world complex networks, harmful spreads, commonly known as contagions, are common and can potentially lead to catastrophic events if uncontrolled. Some examples include pandemics, network attacks on crucial infrastructure systems, and the propagation of misinformation or radical ideas. Thus, it is critical to study the protective measures that inhibit or eliminate contagion in these networks. This is known as the network protection problem.
The network protection problem investigates the most efficient graph manipulations (e.g., node and/or edge removal or addition) to protect a certain set of nodes known as critical nodes. There are two types of critical nodes: (1) …
Distortion Estimates For Conformal Maps Predicated On Geometric Properties Of A Domain, Christopher G. Donohue
Distortion Estimates For Conformal Maps Predicated On Geometric Properties Of A Domain, Christopher G. Donohue
Dissertations - ALL
Geometric properties of a domain in the complex plane reflect important informationabout the conformal maps to and from the domain. We examine a variety of geometric properties and use them to construct explicit global distortion bounds for both the compression and stretching of conformal map. Compressive distortion is controlled when the modulus of the derivative of a complex function is bounded from below, expansive distortion when it is bounded above. For the initial set of results, we quantify the degree to which a convex domain is nearly round with two parameters; radii of the largest inscribed disk and smallest circumscribed …
Investigation Of Holographic Lattice Theories, Muhammad Asaduzzaman
Investigation Of Holographic Lattice Theories, Muhammad Asaduzzaman
Dissertations - ALL
The Anti-de Sitter/Conformal Field theory (AdS/CFT) correspondence, also known as holography, has been the focus of a great deal of interest and research for the last two decades. It has improved our understanding of general relativity and quantum field theories simultaneously through the interplay between these two different kinds of theories. However, there are still many aspects of holography that we do not understand or demand further analysis. Perturbative quantum field theory and perturbative metric expansion techniques are not equipped to investigate holography in some of the most interesting regimes such as the strongly interacting gravitational theory in anti-de Sitter …
Geometry Of Discrete And Continuous Bounded Surfaces, Kyung Eun Kim
Geometry Of Discrete And Continuous Bounded Surfaces, Kyung Eun Kim
Dissertations - ALL
We work on reconstructing discrete and continuous surfaces with boundaries using length constraints. First, for a bounded discrete surface, we discuss the rigidity and number of embeddings in three-dimensional space, modulo rigid transformations, for given real edge lengths. Our work mainly considers the maximal number of embeddings of rigid graphs in three-dimensional space for specific geometries (annulus, strip). We modify a commonly used semi-algebraic, geometrical formulation using Bézout's theorem, from Euclidean distances corresponding to edge lengths. We suggest a simple way to construct a rigid graph having a finite upper bound. We also implement a generalization of counting embeddings for …
Evaluation Of The Energetic Factors In Crystalline Pharmaceuticals Using Solid-State Density Functional Theory And Low-Frequency Vibrational Spectroscopy, Margaret P. Davis
Evaluation Of The Energetic Factors In Crystalline Pharmaceuticals Using Solid-State Density Functional Theory And Low-Frequency Vibrational Spectroscopy, Margaret P. Davis
Dissertations - ALL
Due to the importance of maintaining stable and effective pharmaceutical solid doses, it is critical to study the variety of solid forms that active pharmaceutical ingredients can adopt including polymorphs, hydrates, and cocrystals. In this work, low-frequency vibrational spectroscopies and rigorous quantum mechanical simulations are combined to provide a new technique for characterizing and investigating pharmaceutically relevant polymorphs, hydrates, and cocrystals as well as a series of model cocrystals. Low-frequency spectra in the sub-200 cm-1 range provide not only unique and characteristic spectra for all of the systems explored here but, along with X-ray structural parameters, they offer a way …
Adversarial Activity Detection And Prediction Using Behavioral Biometrics, Amin Fallahi
Adversarial Activity Detection And Prediction Using Behavioral Biometrics, Amin Fallahi
Dissertations - ALL
Behavioral biometrics can be used in different security applications like authentication, identification, etc. One of the trending applications is predicting future activities of people and guessing whether they will engage in malicious activities in the future. In this research, we study the possibility of predicting future activities and propose novel methods for near-future activity prediction.
First, we study gait signals captured using smartphone accelerometer sensor and build a model to predict a future gait signal. Activity recognition using body movements captured from mobile phone sensors has been a major point of interest in recent research. Data that is being continuously …
Characterization Of Scintillation Light In Large Liquid Argon Detectors And The Implications For Proton Decay Searches, Kyle Spurgeon
Characterization Of Scintillation Light In Large Liquid Argon Detectors And The Implications For Proton Decay Searches, Kyle Spurgeon
Dissertations - ALL
The Deep Underground Neutrino Experiment (DUNE) is a planned long baseline neutrino experi- ment. The detector will be comprised of four modules with 10kt of active volume each, making it an ideal target to neutrino oscillation physics and searches for proton decay. ProtoDUNE-SP was a single-phase liquid argon time projection chamber - a prototype for the first far detector module of DUNE with an active volume of 700 tons operating until 2020. It was installed at the CERN Neutrino Platform and took particle beam and cosmic ray data over its two year lifespan. Liquid argon scin- tillation light is still …
Measurement Of |Vcb| Using The Semileptonic Decay Λb → Λcμνμ, Scott Edward Ely
Measurement Of |Vcb| Using The Semileptonic Decay Λb → Λcμνμ, Scott Edward Ely
Dissertations - ALL
A preliminary measurement of the quark-mixing parameter |Vcb| using the exclusive decay Λ0b→ Λ+c μ−νμ is presented. A sample of Λb semileptonic decays is provided by √s = 13TeV proton-proton collisions collected by the LHCb detector in 2017. Λ0b → Λ+c μ−νμX decays are identified from muon tracks, combined with a Λc baryon. The ground state Λ0b → Λ+c μ−νμ is isolated by a fit to the Λb corrected mass spectrum. The raw yield NRaw(Λ0b → Λ+c μ−νμ) is corrected, and the semileptonic width ΓMeas. (Λ0b → Λ+c μ−νμ) is obtained. Lattice QCD calculations predict ΓTh.(Λ0b → Λ+c μ−νμ)/|Vcb|2. A …
A New Class Of Antibiotic That Prevents Drug Tolerance, Persistence, And Resistance By Controlling Emergence Of Phenotypes., Pankaj Dinkar Patil
A New Class Of Antibiotic That Prevents Drug Tolerance, Persistence, And Resistance By Controlling Emergence Of Phenotypes., Pankaj Dinkar Patil
Dissertations - ALL
The fight against bacterial infections and innovations in antibiotic therapy has never halted throughout human history. However, bacteria have evolved smartly and resistance against practically all conventional antibiotics has been developed. Furthermore, bacteria can form biofilms, which are surface-attached multicellular colonies. Biofilms shield bacteria against antibiotics and makes it harder to entirely eradicate infections . Under antibiotics stress, bacteria evolve into different phenotypes like hyper motile, hyper adherent and hyper virulent which are tolerant and persistent to antibiotic treatment. The use of antibiotic therapy to combat such resilient bacterial phenotypes is extremely tough. As a result, the scientific community is …
Constraining Beam Backgrounds And Analyzing The Detector Response In A Test Beam With The Nova Experiment, Abhilash Yallappa Dombara
Constraining Beam Backgrounds And Analyzing The Detector Response In A Test Beam With The Nova Experiment, Abhilash Yallappa Dombara
Dissertations - ALL
NOvA is a long-baseline neutrino oscillation experiment with two functionallyidentical detectors with the Near Detector at Fermilab, Illinois, and the Far Detector at Ash River, Minnesota. NOvA measures the rate of muon neutrino disappearance and electron neutrino appearance using muon neutrinos generated by the NuMI beam from the Accelerator Division(AD), thus NOvA measures neutrino oscillation parameters in the Pontecorvo-Maki- Nakagawa-Sakata matrix. The main experimental goal of NOvA is to determine the mass hierarchy, probe Charge-Parity violation and measure sin2 θ23 precisely. In this dissertation, the experimental setup, the latest analysis methods used in NOvA, and its results from analyzing 6 …
Studying Redox Conditions Of Devonian And Neoproterozoic Oceans Using I/Ca Proxy From Bulk Carbonate Rocks, Ruliang He
Studying Redox Conditions Of Devonian And Neoproterozoic Oceans Using I/Ca Proxy From Bulk Carbonate Rocks, Ruliang He
Dissertations - ALL
Iodine is an important trace element in biogeochemical and redox reactions. It has a nearly consistent concentration of ~0.46 μmol/L in the seawater and the inorganic speciation (IO3− and I−) of iodine is primarily controlled by redox conditions in water columns. Iodate (IO3−), not iodide (I−), is the only species that can be incorporated into carbonate minerals. Therefore, I/Ca ratio from carbonate rocks can be used to constrain the redox condition in the water column over a range of time scale. This dissertation contains three chapters that utilizes I/Ca ratio from bulk carbonate rocks to reconstruct ocean redox changes during …
Assessing Impact Of Unconventional Oil And Gas Development On Groundwater Quality In The Northern Appalachian Region With Mixed Land Uses, Favour C. Epuna
Assessing Impact Of Unconventional Oil And Gas Development On Groundwater Quality In The Northern Appalachian Region With Mixed Land Uses, Favour C. Epuna
Theses - ALL
Over the past decade, the rapid growth of unconventional oil and gas development (UOGD) has raised public concerns about its potential impact on groundwater quality. High methane and salt levels in groundwater have been the most widely cited UOGD-related impairments. The attribution of these contaminants to UOGD is usually complex, especially in regions with mixed land uses. Here, we compiled a large hydrogeochemistry dataset containing 13 geochemical analytes for 17,794 groundwater samples from the rural northern Appalachia, i.e., 19 counties located on the boundary between Pennsylvania (PA; UOGD is permitted) and New York (NY; UOGD is banned). With this dataset, …
A Gis Suitability Model Evaluating Habitat Characteristics Influencing Beaver (Castor Canadensis) Lodge Site Selection And Lodge Occupancy In Central Adirondacks, New York, Amanda K. Jacobs
Theses - ALL
The North American beaver (Castor canadensis) represents a quintessential example of an "ecosystem engineer." Yet the species' landscape-scale impacts on hydrology, geomorphology, and ecosystem ecology are not uniformly distributed through landscapes or time. Understanding beaver lodge site selection and lodge fidelity through time can help to predict where the greatest effects of beaver activity may occur. In this research project, I seek to understand the relationships between beaver habitat suitability, the habitat variables that currently define suitable areas, and lodge occupancy over time. Using Geographic Information Systems (GIS) to model habitat suitability, I use hydrologic, vegetative, and physiographic variables to …
Trichloroacetimidates As Outstanding Electrophiles For The Carbon-Nitrogen, Carbon-Oxygen And Carbon-Carbon Bonds Formation And Synthetic Studies Of Protein Phosphatase-5 (Pp5) Small Molecule Inhibitors, Nilamber Mate
Dissertations - ALL
Trichloroacetimidates have been previously used for glycosidic bond formation in carbohydrate chemistry and in Friedel-Craft reactions. Traditionally, trichloroacetimidates had be synthesized using an alcohol and strongly basic conditions, but in recent years milder preparation methods have been reported. Given the ease of preparation of these versatile reagents, their chemistry has been explored intensely in recent years. While few reported methods suggest they can react under promoter free conditions, activation by Lewis or Brønsted acid leads to a formation of a carbocation from benzylic trichloroacetimidates. Work described herein makes use of these convenient carbocation precursors for new reactions.Isatin is an ambidentate …