Physics Commons^™

The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu

Dissertations

The main goal of this dissertation is to generate data and parameterizations to accurately represent soot aerosols in atmospheric models. Soot from incomplete combustion of fossil fuels and biomass burning is a major air pollutant and a significant contributor to climate warming. The environmental impacts of soot are strongly dependent on the particle morphology and mixing state, which evolve continuously during atmospheric transport via a process known as aging. To make predictions of soot impacts on the environment, most atmospheric models adopt simplifications of particle structure and mixing state, which lead to substantial uncertainties. Using an experimentally constrained modeling approach, …

Аn Optical Study Of Strain Relaxation And Interdiffusion In Znse/Zncdse Quantum Wells Modified By Γ-Irradiation, Muratbay B. Sharibaev, Kanatbay A. Ismailov, Ibrohim N. Karimov, Murodjon Z. Nosirov

Scientific Bulletin. Physical and Mathematical Research

If we turn to the literature data, it is known that the degradation of CdZnTe / ZnTe and CdZnSe /ZnSe quantum wells and usually includes two types of processes: (i) fast (as called dynamic, by analogy with the degradation of heterostructures based on A3B5 materials) - germination and propagation of extended defects from a GaAs substrate. This process in CdZnSe / ZnSe is slowed down by various technological methods (treatment of a substrate in sulfur; reduction of a damaged layer in a GaAs substrate; deposition of a GaAs epitaxial buffer layer; use of the concept of compensation of bipolar stresses; …

Obtaining, Structure And Electrophysical Properties Of The Solid Solution (Gaas1-Δbiδ)1-X-Y(Ge2)X(Znse)Y, Hotamjon Mansurov, Akramjon Boboev, Johongir Usmonov, Xushruybek Mahmudov, Dilkhayotjon Pulatjon Ugli Abdurakhimov

Scientific Bulletin. Physical and Mathematical Research

This work shows the possibility of growing a single-crystal substitutional solid solution (GaAs_1-δBi_δ)₀.₄₆(Ge₂)_0.31(ZnSe)_0.23on GaP substrates by liquid phase epitaxy from a bismuth-containing melt solution. was shown that tetrahedral bonds in the (GaAs_1-δBi_δ)₀.₄₆(Ge₂)_0.31(ZnSe)_0.23 layers are enriched with arsenide gallium molecules, and some GaAs_1-δBi_δ molecules are replaced by Ge₂ paired atoms and ZnSe molecule compounds. Experimental results showed that in the epitaxial film, the molar content of GaAs …

Small-Scale Dynamics Of Photospheric Magnetic Activities And Their Chromospheric Responses, Jiasheng Wang

Dissertations

The evolution of photospheric magnetic fields is considered as the fundamental source of forming atmospheric structures and triggering most solar activities, including flares and mass ejections on various scales (CMEs, jets, etc.). With the implementation of high-resolution observational instruments, small-scale details of magnetic features are recognized that can provide important information regarding the evolution in active regions and the connection between photospheric magnetic reconnection and jet-like ejections in the quiet Sun. This research takes advantage of the exceptionally high-resolution measurements of vector magnetic field and imaging observations by the Goode Solar Telescope, and UV/EUV imaging observations from space-based instruments. The …

Blast Shock-Wave Characterization In Experimental Shock Tubes, Sudeepto Kahali

Dissertations

Blast-induced traumatic brain injuries have affected U.S. soldiers deployed for extended periods in the gulf and Afghanistan wars. To identify the biomechanical and biochemical mechanisms of injury, critical in the identification of diagnostic and therapeutic tools, compressed gas-driven shock tubes are used by investigators to study shockwave-animal specimen interactions and its biological consequences. However, shock tubes are designed and operated in a variety of geometry with a range of process parameters, and the quality of shock wave characteristics relevant to field conditions and therefore the study of blast-induced traumatic brain injuries suffered by soldiers is affected by those conditions. Lab-to-lab …

Countering Internet Packet Classifiers To Improve User Online Privacy, Sina Fathi-Kazerooni

Dissertations

Internet traffic classification or packet classification is the act of classifying packets using the extracted statistical data from the transmitted packets on a computer network. Internet traffic classification is an essential tool for Internet service providers to manage network traffic, provide users with the intended quality of service (QoS), and perform surveillance. QoS measures prioritize a network's traffic type over other traffic based on preset criteria; for instance, it gives higher priority or bandwidth to video traffic over website browsing traffic. Internet packet classification methods are also used for automated intrusion detection. They analyze incoming traffic patterns and identify malicious …

Convergence Of The Boundary Integral Method For Interfacial Stokes Flow, Keyang Zhang

Dissertations

Boundary integral numerical methods are among the most accurate methods for interfacial Stokes flow, and are widely applied. They have the advantage that only the boundary of the domain must be discretized, which reduces the number of discretization points and allows the treatment of complicated interfaces. Despite their popularity, there is no analysis of the convergence of these methods for interfacial Stokes flow. In practice, the stability of discretizations of the boundary integral formulation can depend sensitively on details of the discretization and on the application of numerical filters. A convergence analysis of the boundary integral method for Stokes flow …

Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel

Theses

The scalability and power efficiency of the conventional CMOS technology is steadily coming to a halt due to increasing problems and challenges in fabrication technology. Many non-volatile memory devices have emerged recently to meet the scaling challenges. Memory devices such as RRAMs or ReRAM (Resistive Random-Access Memory) have proved to be a promising candidate for analog in memory computing applications related to inference and learning in artificial intelligence. A RRAM cell has a MIM (Metal insulator metal) structure that exhibits reversible resistive switching on application of positive or negative voltage. But detailed studies on the power consumption, repeatability and retention …

Drawing Parallels In Art Science For Collaborative Learning: A Case Study, Karen Westland

The Transdisciplinary STEAM+ Journal

This research paper explores drawing as a tool to facilitate interdisciplinary practice. Outlined is the personal experience of PhD researcher [name removed] in their physics/craft research project, combined with thoughts and opinions from collaborators gathered through group discursive interviews. Interdisciplinary projects face interpersonal and conceptually ambiguous challenges which can be addressed through adopting drawing techniques for educational purposes. Findings highlight that drawing can assist across a breadth of applications as a learning tool for everyone, regardless of drawing ability, to improve the functionality of collaborative projects. Specifically, drawing combined with other communication techniques develops a performative communicative approach that enriches …

Quantum Simulation Of The Schrodinger Equation Using Ibm's Quantum Computers, Mohamed Abouelela

Capstone and Graduation Projects

This thesis explores the capabilities of a quantum computer to simulate quantum systems. We give an introduction to the basics of quantum computing with the Bernstein-Vazirani algorithm as a demonstration. Four quantum systems are then simulated using IBM's QASM simulator using 6 qubits: the free particle, eigenstate of an infinite-well, particle in a step potential, and quantum tunneling. Because of the high number of gates, a 6-qubit simulation will not be feasible on current quantum computers. The number of qubits was, thus, reduced to 4 qubits, and was simulated on IBM's 5 qubit quantum computers (ibmq 5 vigo). We conclude …

Near Conformal Perturbation Theory In Syk Type Models, Sumit R. Das, Animik Ghosh, Antal Jevicki, Kenta Suzuki

Physics and Astronomy Faculty Publications

We present a systematic procedure to extract the dynamics of the low energy soft mode in SYK type models with a single energy scale J and emergent reparametrization symmetry in the IR. This is given in the framework of the perturbative scheme of arXiv:1608.07567 based on a specific (off-shell) breaking of conformal invariance in the UV, adjusted to yield the exact large-N saddle point. While this breaking term formally vanishes on-shell, it has a non-trivial effect on correlation functions and the effective action. In particular, it leads to the Schwarzian action with a specific coupling to bi-local matter. The …

Local Electronic And Magnetic Properties Of The Doped Topological Insulators Bi₂Se₃:Ca And Bi₂Te₃:Mn Investigated Using Ion-Implanted ⁸Li Β-Nmr, Ryan M. L. Mcfadden, Aris Chatzichristos, David L. Cortie, Derek Fujimoto, Yew San Hor, Huiwen Ji, Victoria L. Karner, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We report β-NMR measurements in Bi₂Se₃:Ca and Bi₂Te₃:Mn single crystals using ⁸Li⁺ implanted to depths on the order of 100 nm. Above ∼200K, spin-lattice relaxation reveals diffusion of ⁸Li⁺, with activation energies of ∼0.4eV (∼0.2eV) in Bi₂Se₃:Ca (Bi₂Te₃:Mn). At lower temperatures, the NMR properties are those of a heavily doped semiconductor in the metallic limit, with Korringa relaxation and a small, negative, temperature-dependent Knight shift in Bi₂Se₃:Ca. From this, we make a detailed comparison with …

Numerical Simulation Of Nonlinear Vibrations Of Discrete Mass With Harmonic Force Perturbation, M. Yusupov, B. A. Akhmedov, Olga Karpova

Acta of Turin Polytechnic University in Tashkent

The problem of vibration of a single-mass system under the force excitation of vibration associated with a fixed base by a weightless nonlinear viscoelastic spring is considered. To take into account the rheological properties of the spring material, the Boltzmann-Volterra principle was used. Mathematical models of the problem under consideration are obtained, which are described by integro-differential equations. A solution method based on the use of quadrature formulas has been developed and a computer program has been compiled on its basis, the results obtained are presented in the form of graphs. The influence of nonlinear and rheological properties of a …

Evolution Of Magnetic-Field-Induced Ordering In The Layered Structure Quantum Heisenberg Triangular-Lattice Antiferromagnet Ba3Cosb2O9, Nathanael Alexander Fortune, Q. Huang, T. Hong, J. Ma, E. S. Choi, S. T. Hannahs, Z. Y. Zhao, X. F. Sun, Y. Takano, H. D. Zhou

Physics: Faculty Publications

Quantum fluctuations in the effective spin-1/2 layered structure triangular-lattice quantum Heisenberg antiferromagnet Ba₃CoSb₂O₉ lift the classical degeneracy of the antiferromagnetic ground state in magnetic field, producing a series of novel spin structures for magnetic fields applied within the crystallographic ab plane, including a celebrated collinear ‘up-up-down’ spin ordering with magnetization equal to 1/3 of the saturation magnetization over an extended field range. Theoretically unresolved, however, are the effects of interlayer antferromagnetic coupling and transverse magnetic fields on the ground states of this system. Additional magnetic-field-induced phase transitions are theoretically expected and in some cases have …

Supernovae Distributions And Their Relationships To Classes Of Stars, Sydney Menne

Arts & Sciences Undergraduate Showcase

Aims. Data from astronomical catalogs are plotted as spatial distributions of stars and supernovae throughout the Milky Way galaxy and the universe. I examined correlations seen between the luminosity classes of stars, types of supernovae, and selection effects observed in the data.

Methods. Data was gathered from three catalogs; the Gliese Catalog of Nearby Stars, the Tycho-2 Catalog, and the Open Supernova Catalog. Graphs and diagrams were created to visualize the distributions of the stellar luminosity classes and supernova types at different radial distances from the Sun. Trendlines were fit through the data to examine extrapolated predictions.

Results/Conclusions. Documenting stars …

The Nanograv 12.5 Yr Data Set: Observations And Narrowband Timing Of 47 Millisecond Pulsars, Md F. Alam, Zaven Arzoumanian, Paul T. Baker, Harsha Blumer, Keith E. Bohler, Keeisi Caballero, Richard S. Camuccio, Yhamil Garcia

Physics & Astronomy Faculty Publications

We present time-of-arrival (TOA) measurements and timing models of 47 millisecond pulsars observed from 2004 to 2017 at the Arecibo Observatory and the Green Bank Telescope by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). The observing cadence was three to four weeks for most pulsars over most of this time span, with weekly observations of six sources. These data were collected for use in low-frequency gravitational wave searches and for other astrophysical purposes. We detail our observational methods and present a set of TOA measurements, based on "narrowband" analysis, in which many TOAs are calculated within narrow radio-frequency …

What Is Nonlocal In Counterfactual Quantum Communication?, Yakir Aharonov, Daniel Rohrlich

Mathematics, Physics, and Computer Science Faculty Articles and Research

We revisit the “counterfactual quantum communication” of Salih et al. [1], who claim that an observer “Bob” can send one bit of information to a second observer “Alice” without any physical particle traveling between them. We show that a locally conserved, massless current—specifically, a current of modular angular momentum, Lz mod 2ℏ—carries the one bit of information. We integrate the flux of Lz mod 2ℏ from Bob to Alice and show that it equals one of the two eigenvalues of Lz mod 2ℏ, either 0 or ℏ, thus precisely accounting for the one bit of information he sends her.We previously …

Dft-Based Study Of Electric Field Effect On The Polarizability Of Three Ringed Nematic Liquid Crystal Molecules, Pranav Upadhyay, Mirtunjai Mishra, Ankur Trivedi, Jitendra Kumar, Asheesh Kumar, Devesh Kumar

Makara Journal of Science

Owing to its successful application to complex molecular systems, computational density functional theory (DFT) has been used to study the effect of an electric field on the molecular polarizability and HOMO–LUMO gap of 1-phenyl-4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}benzene (1) and its fluoro-, chloro-, and cyano- derivatives, namely, 1-fluoro-4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzene (2), 1-chloro-4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzene (3), and 4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzonitrile (4). These molecules belong to the family of nematic liquid crystals with three rings: two benzene and one cyclohexane. Furthermore, two DFT approaches, namely, B3LYP and M062X, have been used to examine the results obtained. This study reveals a remarkable feature: the polarizability of these molecules follows nearly a step function …

Traveling-Wave Electrophoresis: 1d Model, Austin Green

Physics Capstone Projects

A 1D model of traveling-wave electrophoresis predicts that molecular diffusion raises the trapping threshold and that other physical properties of the species effect the trapping threshold as well. Small concentrations, below 5μM, raise the trapping threshold for high diffusivity species, resulting in a lower efficiency. Species with a mid-range electrophoretic mobility and diffusivity have their trapping threshold slightly lowered with an increase in concentration, leading to more particles traveling with the wave.

Quantifying Anticancer Drug Doxorubicin Binding To Dna Using Optical Tweezers, Zachary Ells

Honors Program Theses and Projects

Doxorubicin is a successful anticancer drug approved for use in the 1970s and is considered to be one of the most effective cancer treatment methods today. Although Doxorubicin has positive survival statistics it has very negative side effects in many cases. Bleeding from the soles of the palms and feet, along with excruciating pain is often exhibited through the administration of this drug. Based on the preliminary findings utilizing optical tweezers we anticipate that this study will provide critical information about the drug binding mechanism. Single molecule biophysics techniques have provided useful insight into the DNA-binding mechanisms of small molecules. …

Modeling Fluid Phenomena In The Context Of The Constrained Vapor Bubble System, James Barrett

Mathematics Theses and Dissertations

This thesis focuses on the fluid phenomena observed within what is known as the constrained vapor bubble system. The constrained vapor bubble system is a closed system consisting of a quartz cuvette partially filled with liquid and used as a coolant device. Heat is applied to the heater end which causes the liquid to evaporate and condense on the cooled end of the cuvette. Liquid travels back to the heated end via capillary flow in the corners. A pure vapor bubble is formed in the center of the cuvette giving rise to the name of the experiment. The constrained vapor …

Published Research Documents In Nuclear And High Energy Physics From 1996-2019: A Bibliometric Analysis Of Leading Countries In Comparison With India, Ishwar Dutt Sharma Dr

Library Philosophy and Practice (e-journal)

A bibliometric analysis of scientific research production of the top five most productive countries in comparison with India in nuclear and high energy physics is presented during the period 1996-2019 using Scopus-linked SCImago electronic database. To validate the present study, some selected bibliometric indicators such as published documents, their citations and citations per document has been studied. In total, 769180 research documents were published worldwide in journal, conference proceedings and in book series. United States (16.47%), Germany(8.64%), Japan (6.65%), China (6.41%) and Russian Federation (5.89%) were the top most productive countries rankwise, whereas India ranked 10^th with 21157 research …

Modeling Residence Time Distribution Of Chromatographic Perfusion Resin For Large Biopharmaceutical Molecules: A Computational Fluid Dynamic Study, Kevin Vehar

KGI Theses and Dissertations

The need for production processes of large biotherapeutic particles, such as virus-based particles and extracellular vesicles, has risen due to increased demand in the development of vaccinations, gene therapies, and cancer treatments. Liquid chromatography plays a significant role in the purification process and is routinely used with therapeutic protein production. However, performance with larger macromolecules is often inconsistent, and parameter estimation for process development can be extremely time- and resource-intensive. This thesis aimed to utilize advances in computational fluid dynamic (CFD) modeling to generate a first-principle model of the chromatographic process while minimizing model parameter estimation's physical resource demand. Specifically, …

Aerial Mucosalivary Droplet Dispersal Distributions With Implications For Disease Mitigation, Brian Chang, Ram Sudhir Sharma, Trinh Huynh, Arshad Kudrolli

Physics

We investigate mucosalivary dispersal and deposition on horizontal surfaces corresponding to human exhalations with physical experiments under still-air conditions. Synthetic fluorescence tagged sprays with size and speed distributions comparable to human sneezes are observed with high-speed imaging. We show that while some larger droplets follow parabolic trajectories, smaller droplets stay aloft for several seconds and settle slowly with speeds consistent with a buoyant cloud dynamics model. The net deposition distribution is observed to become correspondingly broader as the source height H is increased, ranging from sitting at a table to standing upright. We find that the deposited mucosaliva decays exponentially …

Thermo-Fluid Characterizations Of The Powder-Bed Fusion Additive Manufacturing Processes Using Laser And Electron Beam, M Shafiqur Rahman

LSU New Orleans Theses and Dissertations

The powder-bed fusion (PBF) process is a subdivision of Additive Manufacturing (AM) technology where a heat source at a controlled speed selectively fuses regions of a powder-bed material to form three-dimensional (3-D) parts. Two of the most effective PBF processes are selective laser melting (SLM) and electron beam additive manufacturing (EBAM), which can fabricate full-density metallic parts in a layer-by-layer fashion. In this study, thermal behavior and melt-pool dynamics in the PBF process are investigated by developing 3-D multiphysics-based thermo-fluid models for both SLM and EBAM, containing Ti-6Al-4V alloy as a powder-bed material. The laser and electron beams are modeled …

A Transformative Approach To Incorporating Adaptive Courseware: Strategic Implementation, Backward Design And Research-Based Teaching Practices, Tonya A. Buchan, Stanley Kruse, Jennifer Todd, Lee Tyson

Current Issues in Emerging eLearning

In July 2016, Colorado State University (CSU) joined seven other land-grant institutions in the Accelerating Adoption of Adaptive Courseware grant sponsored by the Personalized Learning Consortium (PLC) of the Association of Public and Land-grant Universities (APLU). A primary objective of the grant was to scale the adoption of adaptive courseware in general education courses at each of the grant institutions. CSU targeted high-enrollment, general education courses and took a three-pronged, transformative approach to the integration of adaptive courseware. Specifically, CSU divided the courseware integration into three components: 1) strategic implementation of courseware, 2) backward course design, and 3) incorporation of …

Retention Of Rising Oil Droplets In Density Stratification, Tracy L. Mandel, De Zhen Zhou, Lindsay Waldrop, Maxime Theillard, Dustin Kleckner, Shilpa Khatri

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In this study, we present results from experiments on the retention of single oil droplets rising through a two-layer density stratification, with the goal of quantifying and parametrizing the impact of stratification on timescales that describe the delay in rising. These experiments confirm the significant slowdown observed in past literature of settling and rising particles and droplets in stratification, and these are the first experiments to study single liquid droplets as opposed to solid particles or bubbles. By tracking the motion of the droplets as they rise through a stratified fluid, we identify two new timescales which quantitatively describe this …

Organic-Inorganic Hybrid Perovskite Promising Materials For Next Generation Solar Cells, Gailan Asad Kazem Al-Dainy

Theses and Dissertations

Scientists and engineers are developing photovoltaic devices as promising clean energy tools. Organic-inorganic hybrid perovskites have attracted considerable attention as next-generation thin film solar cells due to their high efficiency, solution processability, easy processing, and low-cost fabrication. Moreover, perovskite exhibits outstanding optoelectronic properties. These unique properties have led to a rapid rise in their power conversion efficiency (PCE) as single-junction from 3.9% to certified 23.4% in just about 9 years. However, the stability of perovskite solar cell (PSC) -based devices is still an issue, therefore, it is important to increase both the efficiency and stability of PSC devices. Based on …

Toward Non-Invasive Measurement Of Atmospheric Temperature Using Vibro-Rotational Raman Spectra Of Diatomic Gases, Tyler Capek, Jacek Borysow, Claudio Mazzoleni, Massimo Moraldi

Michigan Tech Publications, Part 1

We demonstrate precise determination of atmospheric temperature using vibro-rotational Raman (VRR) spectra of molecular nitrogen and oxygen in the range of 292–293 K. We used a continuous wave fiber laser operating at 10 W near 532 nm as an excitation source in conjunction with a multi-pass cell. First, we show that the approximation that nitrogen and oxygen molecules behave like rigid rotors leads to erroneous derivations of temperature values from VRR spectra. Then, we account for molecular non-rigidity and compare four different methods for the determination of air temperature. Each method requires no temperature calibration. The first method involves fitting …

1. Test Data, Zhiqu Lu, Likun Zhang, Lei Cao

Gulf Research Program Data Sets

This data set contains recorded and processed bubble sounds under different conditions: a few bubbles vs. constant flow bubbles. Each condition is tested with nitrogen and with methane.