Physics Commons^™

Intercalation And High-Pressure Investigations Of Black Arsenic Phosphorus: Unraveling Material Transformations., Dinushika Vithanage

Electronic Theses and Dissertations

Black arsenic phosphorus (b-As_yP_1-y) alloys have emerged as intriguing materials within the realm of two-dimensional (2D) materials, following the discovery of black phosphorus (BP). These alloys possess capability to overcome major limitations of BP and exhibit potential for tunability and enhancement of properties making them promising materials for a wide range of applications, including lithium-ion batteries. Inspired by the intriguing findings obtained for BP, this research focuses on understanding the structural modifications that can be achieved in b-As_yP_1-y alloys through the application of intercalation and high pressure. The initial phase of our investigation …

Super P-Sulfur Cathodes For Quasi-Solid-State Lithium-Sulfur-Batteries., Milinda Bharatha Kalutara Koralalage

Electronic Theses and Dissertations

Lithium-Sulfur (Li-S) batteries have become a promising candidate to meet the current energy storage demand, with its natural abundance of materials, high theoretical capacity of 1672 mAhg-1, high energy density of 2600 Whkg-1, low cost and lower environmental impact. Sulfide based solid state electrolytes (SSEs) have received greater attention due to their higher ionic conductivity, compatible interface with sulfur-based cathodes, and lower grain boundary resistance. However, the interface between SSEs and cathodes has become a challenge in all solid-state Li-S batteries due to the rigidity of the participating surfaces. A hybrid electrolyte containing SSE coupled with a small amount of …

Modeling, Simulation And Control Of Microrobots For The Microfactory., Zhong Yang

Electronic Theses and Dissertations

Future assembly technologies will involve higher levels of automation in order to satisfy increased microscale or nanoscale precision requirements. Traditionally, assembly using a top-down robotic approach has been well-studied and applied to the microelectronics and MEMS industries, but less so in nanotechnology. With the boom of nanotechnology since the 1990s, newly designed products with new materials, coatings, and nanoparticles are gradually entering everyone’s lives, while the industry has grown into a billion-dollar volume worldwide. Traditionally, nanotechnology products are assembled using bottom-up methods, such as self-assembly, rather than top-down robotic assembly. This is due to considerations of volume handling of large …

First Principles Study Of 2d Polar Heterostructures., Safia Abdullah R Alharbi

Electronic Theses and Dissertations

Recently, two-dimensional (2D) heterostructures have attracted extensive attention in nanomaterials science. They have been successfully fabricated and applied to nanotechnology in many fields, such as nanoelectronics, solar cells, sensors, energy stores, quantum information, etc. The most common heterostructures are 2D-lateral heterostructure (LH) and 2D-vertical heterostructure (VH) where each of them exhibits unique features depending on the direction of assembly, i.e., along in-plane or out-of-plane direction. Beyond the van der Waals-VH which possess of van der Waals (vdW) interaction, there are other types of heterostructures made of 2D polar materials that possess different types of chemical bonding nature, e.g., chemical bonds …

A Computational Model Of The Line-1 Retrotransposon Life Cycle And Visualization Of Metabolic Networks In 3-Dimensions., Michael D. Martin

Electronic Theses and Dissertations

Computational modeling of metabolic reactions and cellular systems is evolving as a tool for quantitative prediction of metabolic parameters and reaction pathway analysis. In this work, the basics of computational cell biology are presented as well as a summary of physical processes within the cell, and the algorithmic methods used to find time dependent solutions. Protein-protein and enzyme-substrate interactions are mathematically represented via mass action kinetics to construct sets of linear differential equations that describe reaction rates and formation of protein complexes. Using mass action methods, examples of reaction networks and their solutions are presented within the Virtual Cell simulation …

Search For A Dark Leptophilic Scalar Produced In Association With Taupair In Electron-Positron Annihilation At Center-Of-Mass Energies Near 10.58 Gev., Diptaparna Biswas

Electronic Theses and Dissertations

Dark matter is believed to be a form of matter which seemingly accounts for approximately 85% of the matter in the universe and about 27% of its total mass–energy density. It doesn't participate in electromagnetic interaction, i.e. doesn't interact with light. Consequently, we cannot see it using optical or radio telescope and hence the name dark matter. However, it participates in gravitational interaction, and we hypothesize its existence based on a variety of astrophysical observations, including gravitational effects, that cannot be explained by the accepted theories of gravity unless we account for more matter than can be perceived through electromagnetic …

The Impact Of Sea-Level Rise In Numerically Modeled Landfalling Hurricanes: Katrina And The Gulf Coast., Serenity Nadirah Mercuri

Electronic Theses and Dissertations

With climate change, landfalling hurricanes become an increasing threat to coastal regions. However, the interactions between the coastal landscape and landfalling hurricanes are often overlooked when addressing sea-level rise outside of inundation and independent of sea surface temperature. This study analyzed the potential impacts regarding structure and intensity as a result of sea-level rise in the Gulf of Mexico using the WRF-ARW numerical model coupled with a 1D ocean model. Analysis showed that 10 m windspeed from landfall forward was higher in modified coastlines, and minimum sea-level pressure post-landfall was consistently lower for modified runs where storms maintain a higher …

Towards Long Term Colloid Suspension In A Vertically Rotated System., Md Mahmudur Rahman

Electronic Theses and Dissertations

Within a colloidal suspension gravity may compromise the observation of governing physical interactions, especially those that are weak and/or take significant time to develop. Conducting the experiment in a long-term microgravity environment is a viable option to negate gravitational effects, though significant resources are required to do so. While it may not be possible to simulate long-term microgravity terrestrially, particles can resist quick sedimentation in a confined suspension system rotating vertically with appropriate rotation speed. The goal of the investigation is to demonstrate the existence of long-term particle suspension regime for a certain colloidal suspension while characterizing colloidal behavior due …

Ultrafast Magnetic Entropy Dynamics With Time-Resolved Pump-Probe Magneto-Optical Technique., Sahar Goharshenasanesfahani

Electronic Theses and Dissertations

It has been observed that ultrathin films, multilayers, or magnetic nanostructures indicate novel magnetic phenomena that differ profoundly from the respective bulk properties. Besides, because of the broad applications of these magnetic materials in the industry, they are an exciting research area. Hence, investigating the low-dimensional magnetic systems is one of the most active fields in experimental condensed matter physics. Magnetization dynamics can occur over a wide range of time scales (from seconds to femtoseconds). Some of these processes even occur on time scales as short as a few picoseconds (10^-12s) or femtoseconds (10^-15s). Measurement of …

First Principle Studies Of The Effects Of Alkali-Metal Intercalation On Structural Transition From Black To Blue Phosphorene And The Adsorption Of N2h4 On Ws2 Layers., Md Rajib Khan Musa

Electronic Theses and Dissertations

A comprehensive density functional theory calculation has been conducted to seek a potential structural transition from black to blue phosphorene layers, with a focus on the roles played by alkali-metal intercalation in black phosphorene/phosphorus. This study reveals that at sufficiently high Li concentration and specific, well-defined configurations, a phase transition from black to blue phosphorene can take place. The Li atoms intercalated in black phosphorene could act as a “catalyst” in the“reactive region” of the lone pair of P atoms, leading to a P-P bond breaking and, subsequently, a local structural transformation from an orthorhombic lattice to an assembly of …

Structural, Vibrational And Transport Properties Of Novel Complex Systems., Bhupendra Man Shing Karki

Electronic Theses and Dissertations

Electron correlation effects in quantum materials are very strong. It is critical to investigate the structure of quantum materials to better understand and manipulate their physical properties. Quantum effects are prominent at the atomic microscopic length scale, which can not be examined by average long range structural measurements using traditional diffraction methods. Instead, pair distribution function (PDF) analysis, a local structure probe, can effectively unveil the mystery of local structure, which is more sensitive to local behavior than bulk average features. The first section of my dissertation will concentrate on the local structural study of the Iron oxy-chalcogenides, {\cSSe}, which …

Intercalation And High Pressure Studies Of Black Phosphorous - Pathways To Novel Materials And Physics., Manthila Chathurange Rajapakse

Electronic Theses and Dissertations

Discovery of graphene in 2004 initiated a new trend of materials known as two-dimensional (2D) materials which have exciting surface properties and anisotropies than their bulk counterparts. Phosphorene, which is the layered version of black phosphorous (BP) is one of the top 2D materials in terms of research interests and applications of the present day. Moving a step further, our interest is to understand the possibilities for structural modifications of phosphorene, by means of stimuli such as intercalation and high-pressure. It has been predicted by theoretical studies that these stimuli may lead to the formation of new structures and phases …

Study Of Neutral Hadron Production In A High Intensity Particle Physics Experiment., Jake W. Berg

Electronic Theses and Dissertations

In this dissertation I present independent measurements of the multiplicities, R, of π⁰ and η mesons produced in annihilation interactions of electrons and positrons at a center-of-mass energy of 10.54 GeV. Data were collected using the BaBar detector at the PEP-II storage rings located at the SLAC National Accelerator Laboratory in Menlo Park, California. Both mesons have a decay mode to two photons, which is used to identify them and measure their production per event. I find R(π⁰) = 2.8±0.3 per event and R(η) = 0.25±0.03 per event. I also present my contributions to …

Ga-Based Iii-V Semiconductor Photoanodes For Solar Fuels And Novel Techniques To Investigate Their Photocorrosion., Sahar Pishgar

Electronic Theses and Dissertations

Solar energy is one of the most abundant renewable energy sources. However, the diurnal variation of the sun as well as seasonal and weather effects, limits the widespread global implementation of solar energy. Thus, Cost-effective energy storage is critical to overcome the intermittent nature of solar energy available on the earth. Photoelectrolysis of water to oxygen and hydrogen fuel is a promising large-scale solution to store intermittent solar energy in a dense and portable form. Photoelectrochemical (PEC) water-splitting, or artificial photosynthesis, research strives to develop a semiconductor photoelectrode with both high efficiency and long-term stability. Semiconductors of the III–V class …

Development And Applications Of Condensed Phase Cavity Ring-Down Spectroscopy For Studies Of Electrochemical And Interfacial., Shadi Ahmad Alnaanah

Electronic Theses and Dissertations

This dissertation reports the development of ultra-sensitive platforms based on the laser cavity ring-down spectroscopic (CRDS) technique to enable optical and spectroelectrochemical investigations in the condensed phase of matter at challenging scenarios. Firstly, an electrically-active solid/liquid interface for the evanescent-wave cavity ring-down spectroscopy (EW-CRDS) was developed to specroelectrochemically investigate redox events. By coating the interface of total internal reflection of the EW-CRDS platform with a high quality optically transparent and electrically conductive indium tin oxide thin film (ITO), we demonstrated that sufficiently long ring-down times can be achieved to allow for spectroelectrochemical investigations of redox species at solid/liquid interfaces at …

Exploring Information For Quantum Machine Learning Models, Michael Telahun

Electronic Theses and Dissertations

Quantum computing performs calculations by using physical phenomena and quantum mechanics principles to solve problems. This form of computation theoretically has been shown to provide speed ups to some problems of modern-day processing. With much anticipation the utilization of quantum phenomena in the field of Machine Learning has become apparent. The work here develops models from two software frameworks: TensorFlow Quantum (TFQ) and PennyLane for machine learning purposes. Both developed models utilize an information encoding technique amplitude encoding for preparation of states in a quantum learning model. This thesis explores both the capacity for amplitude encoding to provide enriched state …

A Structural Study Of Correlated Materials: Incipient Mott Insulators And Low-Dimensional Systesm., Alaa Alfailakawi

Electronic Theses and Dissertations

Current theories of high-temperature superconductivity suggest that electrons must organize into Cooper pairs in order for a material to exhibit a superconducting phase. Electrons in insulators experience significant repulsive interactions that tend to keep electrons localized at atomic positions. In contrast, electrons in metals are delocalized, interact weakly, and are free to conduct electricity. Therefore, the formation of Cooper pairs should have different mechanisms for metals compared to insulators. This contrast raises the debate about the origin of high-temperature superconductivity in iron-based material, whether it depends on the strong or weak coupling. Many iron-based materials are metallic in the normal …

Search For New Physics Using Lepton Flavor Violating Signatures In Modern Particle Colliders., Atanu Pathak

Electronic Theses and Dissertations

Charged lepton flavor violation is a clear signal of new physics. Such decays are not allowed in the Standard Model but highly anticipated in a large class of new physics models. A direct search for lepton flavor violation in decays of the Higgs boson with the ATLAS detector at the LHC is presented here. The analysis is performed in the H → l tau channel, where the leading lepton (l) can be either an electron or a muon, and the tau lepton decays into an opposite flavored lighter lepton or via the hadronic decay channel. Published results of this search …

Electrochemically-Modulated Surface Plasmon Waves At A Nano-Scale For Investigations And Applications Of Redox Assemblies., Aymen Hasan Qatamin

Electronic Theses and Dissertations

In this thesis, an electrochemically-modulated surface plasmon resonance (EC-SPR) technique was developed for challenging investigations and applications in different redox assemblies. The principle of the technique is based on the nano-scale confined and sensitive interplay between a surface plasmon wave and a redox-active probe featuring an optical transition when undergoing a faradaic redox process. Such faradaic process is electrochemically controlled by modulating the surface electric potential of the SPR platform to create an optical output signal that is substantially immune to the negative impacts of background environment and enabling the identification and quantification minute properties linked to a molecular event …

Lithium Molybdate-Sulfur Battery., Ruchira Ravinath Dharmasena

Electronic Theses and Dissertations

Rechargeable energy storage systems play a vital role in today’s automobile industry with the emergence of electric vehicles (EVs). In order to meet the targets set by the department of energy (DOE), there is an immediate need of new battery chemistries with higher energy density than the current Li- ion technology. Lithium–sulfur (Li–S) batteries have attracted enormous attention in the energy-storage, due to their high specific energy density of 2600 Wh kg^-1 and operational voltage of 2.0 V. Despite the promising electrochemical characteristics, Li-S batteries suffer from serious technical challenges such as dissolution of polysulfides Li₂S_{x …}

A Study On Radiative Pion Capture As A Source Of Background In The Search For Muon To Electron Conversion At The Mu2e Experiment., Joseph Leibson

Electronic Theses and Dissertations

The following thesis will cover the process of radiative pion capture in the Mu2e experiment at Fermi National Accelerator Laboratory. Radiative pion capture (RPC) is a process that is able to mimic the signal of an electron spawned from the neutrino-less conversion of a muon. In this paper we will discuss the current Standard Model accepted by physicists, and discuss charged lepton flavor violation, which is the motivation behind Mu2e. This paper will cover the theory behind Mu2e and RPC, as well as the apparatus involved in the Mu2e experiment. Next, software and simulations used to carry out the RPC …

2d Materials Based Heterostructures : A Lithography Free Method., Adel Alruqi

Electronic Theses and Dissertations

Many properties of Two-dimensional (2D) materials are vastly different from those of their 3D counterparts. A large family of 2D materials ranging from gapless graphene to metallic NbSe2 (also superconducting), semiconducting MoS2, and insulating hexagonal boron nitride (h-BN) possessing a broad range of exciting new properties have emerged in recent years. Moreover, 2D materials provide the perfect platform to create laterally and vertically stacked heterostructures with intriguing properties. The physics of 2D materials based heterostructures is extremely interesting and novel 2D-heterostructured devices including tunneling diodes, tunneling transistors, photovoltaic cells, and light-emitting diodes have started to emerge. In this work, we …

Innate Immunity, The Hepatic Extracellular Matrix, And Liver Injury: Mathematical Modeling Of Metastatic Potential And Tumor Development In Alcoholic Liver Disease., Shanice V. Hudson

Electronic Theses and Dissertations

The overarching goals of the current work are to fill key gaps in the current understanding of alcohol consumption and the risk of metastasis to the liver. Considering the evidence this research group has compiled confirming that the hepatic matrisome responds dynamically to injury, an altered extracellular matrix (ECM) profile appears to be a key feature of pre-fibrotic inflammatory injury in the liver. This group has demonstrated that the hepatic ECM responds dynamically to alcohol exposure, in particular, sensitizing the liver to LPS-induced inflammatory damage. Although the study of alcohol in its role as a contributing factor to oncogenesis and …

Computational Prediction, Characterization, And Methodology Development For Two-Dimensional Nanostructures: Phosphorene And Phosphide Binary Compounds., Congyan Zhang

Electronic Theses and Dissertations

In this thesis, a comprehensive computational simulation was carried out for predicting, characterizing, and applications of two-dimensional (2D) materials. The newly discovered GaP and InP layers were selected as an example to demonstrate how to explore new 2D materials using computational simulations. The performance of phosphorene as the anode material of Lithium-ion battery was discussed as the example of the application of 2D material. Furthermore, the semi-empirical Hamiltonian for phosphorous and lithium elements have been developed for our future work on the application of phosphorus and lithium-based systems. The novel 2D materials of GaP and InP binary compounds were found …

Plasma Based Synthesis And Surface Modification Of Graphene., Rong Zhao

Electronic Theses and Dissertations

Graphene, an atom thick layer of carbon, has attracted intense scientific interest due to its exceptional electrical, mechanical and chemical properties. Especially, it provides a perfect platform to explore the unique electronic properties in absolute two-dimension. Pristine graphene possesses zero band gap and weakens its competitiveness in the field of semiconductors. In order to induce a band gap and control its semiconducting properties, functionalization and doping are two of the most feasible methods. In the context of functionalization, large area monolayer graphene synthesized by chemical vapor deposition was subjected to controlled and sequential fluorination using radio frequency plasma while monitoring …

High Dynamic Range Optical Devices And Applications., Elijah Robert Jensen

Electronic Theses and Dissertations

Much of what we know about fundamental physical law and the universe derives from observations and measurements using optical methods. The passive use of the electromagnetic spectrum can be the best way of studying physical phenomenon in general with minimal disturbance of the system in the process. While for many applications ambient visible light is sufficient, light outside of the visible range may convey more information. The signals of interest are also often a small fraction of the background, and their changes occur on time scales so quickly that they are visually imperceptible. This thesis reports techniques and technologies developed …

Photonic Tools For Advanced Sensing And Imaging At The Nanoscale., Jafar Hamed Ghithan

Electronic Theses and Dissertations

This dissertation reports a novel bio-sensing strategy based on single-mode, electro-active, integrated optical waveguide (SM-EA-IOW) platforms. It also reports the development of a super-resolved far-field optical imaging tool to enable optical, electronic, and spectroelectrochemical investigations at the nanoscale. SM-EA-IOW platforms with its outstanding sensitivity for spectroelectrochemical interrogation was combined with a sandwich bioassay for the development of a novel immunosensing based strategy for label-free detection of infectious pathogens. The strategy begins with the functionalization of the electroactive waveguide surface with a capturing antibody aimed at a specific target analyte. Once the target analyte is bound to the photonic interface, it …

Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin

Electronic Theses and Dissertations

Gas analysis is an important part of our world and gas sensing technology is becoming more essential for various aspects of our life. A novel approach for gas mixture analysis by using portable gas chromatography in combination with an array of highly integrated and selective metal oxide (MOX) sensors has been studied. We developed a system with small size (7 x 13 x 16 inches), low power consumption (~10 W) and absence of special carrier gases designed for portable field analysis (assuming apriori calibration). Low ppb and even sub-ppb level of detection for some VOCs was achieved during the analysis …

Numerical Investigation Of Drop Impingement On Dry And Wet Surfaces., Yisen Guo

Electronic Theses and Dissertations

In-flight icing due to supercooled large droplets (SLDs) imposes great danger on aviation safety. Because of the large size, SLDs have different characteristics than typical cloud droplets that most icing encounters involve. As a result, SLDs more likely hit the wing surface and move into areas not protected by de-icing devices to form ice, which can lead to loss of lift, increase in drag, altered controllability, and eventually stall and loss of control of the aircraft. The phenomenon of droplet splashing is considered as the most important aspect of the SLD icing accretion problem. Although previous studies have established splashing …

All-Optical Switching In Ferromagnetic Superlattices., Faren Hoveyda Marashi

Electronic Theses and Dissertations

The unexpected observation of ultrafast demagnetization (UDM) and subsequent time-resolved studies of laser-induced magnetization switching opened a new door to both fundamental physics and technological applications of magnetic materials. All-optical switching (AOS) can be initiated faster than the precession limit, hinting to its potential in increasing the writing speed and data storage density. However, notwithstanding considerable research interest, the mechanism of AOS in ferromagnetic materials remained unclear.

Ferromagnetic superlattices were deposited on glass substrates with e-beam evaporation and sputtering. Magnetization curves were measured in magneto-optical and vibrating sample magnetometer experiments. A femtosecond Ti:S laser was utilized in a writing setup …