Physics Commons^™

Dimension Reduction Techniques For High Dimensional And Ultra-High Dimensional Data, Subha Datta

Dissertations

This dissertation introduces two statistical techniques to tackle high-dimensional data, which is very commonplace nowadays. It consists of two topics which are inter-related by a common link, dimension reduction.

The first topic is a recently introduced classification technique, the weighted principal support vector machine (WPSVM), which is incorporated into a spatial point process framework. The WPSVM possesses an additional parameter, a weight parameter, besides the regularization parameter. Most statistical techniques, including WPSVM, have an inherent assumption of independence, which means the data points are not connected with each other in any manner. But spatial data violates this assumption. Correlation between …

Amyloid Proteins And Fibrils Stability, Farbod Mahmoudinobar

Dissertations

Compared to globular proteins that have a stable native structure, intrinsically disordered peptides (IDP) sample an ensemble of structures without folding into a native conformation.One example of IDP is the amyloid-beta(Abeta) protein which is the main constituent of senile plaques in the brain of Alzheimer's patients.Understanding the process by which IDPs undergo structural changes to form oligomers that eventually aggregate into senile plaques/amyloid fibrils may significantly advance the development of novel therapeutic methods to treat neurodegenerative diseases, for which there is no cure to date. This dissertation has two main objectives. The first one is to investigate and identify structural …

The Mosdef Survey: [Siii] As A New Probe Of Evolving Interstellar Medium Conditions, Ryan L. Sanders, Tucker Jones, Alice E. Shapley, Naveen A. Reddy, Mariska Kriek, Alison L. Coil, Brian Siana, Bahram Mobasher, Irene Shivaei, Sedona H. Price, William R. Freeman, Mojegan Azadi, Gene C.K. Leung, Tara Fetherolf, Tom O. Zick, Laura De Groot, Guillermo Barro, Francesca M. Fornasini

Pacific Faculty Work

We present measurements of [S III]λλ9069,9531 for a sample of z ∼ 1.5 star-forming galaxies, the first representative sample with measurements of these lines at z ≿ 0.1. We employ the line ratio S32 ≡ [S III]λλ9069,9531/[S II]λλ6716,6731 as a novel probe of evolving interstellar medium (ISM) conditions. Since this ratio includes the low-ionization line [S II], it is crucial that the effects of diffuse ionized gas (DIG) on emission-line ratios be accounted for in z ∼ 0 galaxy spectra, or else that comparisons be made to samples of local H II regions in which DIG emission is not present. …

Features Of The Physical Properties Of The Modified Surface Of The P-Cdte – Znse Film Heterostructure With Deep Impurity Levels, Yuozas Y. Vaytkus, Nodir E. Alimov, Salim M. Otajonov

Scientific Bulletin. Physical and Mathematical Research

This article analyzes the spectrum of the photocurrent in a layered film heterostructure CdTe-ZnSe with deep primesnymi levels. The experimental results demonstrated that the heterostructure CdTe-ZnSe observed a new effect in the measurement of the photoconductivity spectra, depending on the direction of the applied electric field, and the applied field stimulates the emergence of photo-emf. The spectrum of the photocurrent in a layered CdTe- ZnSe heterostructure film with deep impurity levels are considered in the article. It follows from the experimental results that a new effect is observed in the CdTe-ZnSe heterostructure when measuring the photoconductivity spectra depending on the …

Definition Of Extended Structural Defects In Epitaxial Films Of Znteg‘Gaas Grown By Mbe, Muratbay B. Sharibaev, Kanatbay A. Ismailov, Ibrohim N. Karimov, Murodjon Z. Nosirov

Scientific Bulletin. Physical and Mathematical Research

The last three decades of the development of solid state physics are characterized by the fact that the main objects of research are increasingly not massive crystals, but thin films, multilayer thin-film systems, conducting filaments and crystallites of small size. Epitaxial films are grown on a substrate of a single crystal of the same or another material. In the first case, the epitaxial layer with the correct technology becomes a natural extension of the substrate. Epitaxial film can be doped with various impurities. To introduce an alloying admixture into the epitaxial film, three methods are used. According to the first …

Spectral Characteristics Of The Absorption Coefficient And Energy Position Of Defects, Sirojiddin Z. Zaynobidinov, Rustamjon G. Ikramov, Mashhurahon A. Nuriddinova, Khurshid A. Muminov

Scientific Bulletin. Physical and Mathematical Research

In this paper, a theoretical method to study the spectral characteristics of the absorption coefficient, namely the area of ​​defective absorption of amorphous hydrogenated silicon according to the Davis-Mott approximation from the Kubo-Greenwood formula. It is shown that using the experimental spectral characteristic of the defect absorption coefficient, one can determine the energy position of defects in the mobility gap. Optical transitions of electrons, in which electronic states participate in defects, indicate that there are three types of optical transitions of electrons: between defects, between defects and tails of allowed zones, and also between defects and allowed zones. It was …

Sub-Barrier And Above-Barrier Electron Transport Through Multilayer Semiconductors, Vohob R. Rasulov, Rustam Y. Rasulov, Ikbol M. Eshboltaev, Ravshan R. Sultonov

Scientific Bulletin. Physical and Mathematical Research

In the article the transparency coefficients of the semiconductor structure, consisting of alternating asymmetric potential barriers and wells, where the Bastard condition is taken into account, are calculated. It is shown that in the structure there should be an oscillation of the transmission coefficient of electrons depending on their energy, which is due to the interference of the de Broglie waves reaching the barrier and reflected from the potential barrier. The electronic states of a multilayer semiconductor structure consisting of alternating potential wells and barriers are analyzed. It has been shown that both in the above-barrier and in the barrier …

Scientific Foundation Of The Rate Of Falling Of Raw Materials On Walnut Breakage Device, Otabek A. Mirzaev, Xolhuzha A. Sobirov, Nusratillo R. Barakaev

Scientific Bulletin. Physical and Mathematical Research

Today, there are many types of fruits that are separated the kernel from the shell: walnuts, almonds, filberts, chestnuts, pistachios and cashews. Nuts have a high calorific value and a rich nutrient composition. The most critical and delicate operation is shell cracking to extract the fragile whole kernel from the shell. Studies on nut rupturing are particularly focused on the following three aspects: the physical characteristics of nuts, the mechanical properties of nut rupturing, and nut rupturing equipment. Determining the velocity of the nut entered into the apparatus will allow the machine to operate normally, but will also increase its …

Studies Of Tribotechnical Properties Of Composite Polymeric Materials Of Machine Designation, Tojiboy O. Almataev, Nozimbek T. Almataev

Scientific Bulletin. Physical and Mathematical Research

In the given work are experimentally investigated tribotechnical properties as intensity of wear process and factor of a friction composite epoxy the polymeric materials processed by ultrasound. Results of influence of a kind and the maintenance loading on tribotechnical properties composite epoxy polymeric materials depending on modes of ultrasonic processing are received. Correlation dependence of intensity of wear process and factor of a friction composite epoxy coverings from modes of ultrasonic processing is established. It is shown in the work that with an increase in the duration of ultrasonic exposure, the wear rate and the friction coefficient of the coatings …

Structure And Electro Physical Properties Of Solid Solution (Si2)1-X(Cds)X (0 £ X £ 0.01), Xurshidjon M. Madaminov

Scientific Bulletin. Physical and Mathematical Research

This paper shows the possibility of obtaining a single-crystal solid solution for the substitution of p-Si-n-(Si2)1-x (CdS)x (0 £ x £ 0.01) on silicon substrates with a diameter of 20 mm and thickness » 400, with a crystallographic orientation (111) n-types of conductivity with a specific resistance of 1 Ω cm, by the method of liquid phase epitaxy from Sn – Si – CdS solution – melt in a hydrogen atmosphere purified by palladium. Perfect epitaxial layers with mirror surfaces and with the best parameters are grown under the following technological conditions: temperatures start crystallization –1150 ОС, speed of forced …

Application Of Optoelectron Converters Of Reflective Type For Automation Of Liquid And Gas Version Test Measuring Units, Yuriy G. Shipulin, Otabek T. Almataev

Scientific Bulletin. Physical and Mathematical Research

This work is devoted to the use of reflective optoelectronic converters for the automation of liquid and gas calibration flowmeter installations. Liquid and gas calibration flowmeter devices are widely used for verification and certification of various liquid and gas flowmeters and meters. The analysis of the principles of construction of a reflective optoelectronic converter for calibration devices is carried out and the basic principles of their construction are determined. A functional diagram of an experimental automated programmable calibration test setup of flow meters, liquid meters developed on the basis of ROC is presented. High accuracy requirements are imposed on the …

Domain-Wall Tunneling Electroresistance Effect, M. Li, L. L. Tao, Evgeny Y. Tsymbal

Department of Physics and Astronomy: Faculty Publications

Ferroelectric tunnel junctions (FTJs) utilizing an in-plane head-to-head ferroelectric domain wall (DW) have recently been realized, showing interesting physics and new functionalities. However, the DW state in these junctions was found to be metastable and not reversible after applying an electric field. In this work, we demonstrate that a stable and reversible head-to-head DW state can be achieved in FTJs by proper engineering of polar interfaces. Using density functional theory (DFT) calculations and phenomenological modeling, we explore the DW stability by varying stoichiometry of the La_1−xSr_xO=TiO₂ interfaces in FTJs with La_0.5Sr_{0.5 …}

Investigation Of Membrane Protein Dynamics Using Correlative Single-Particle Tracking And Super-Resolution Microscopy Combined With Bayesian Inference Of Diusion In Arbitrary Landscapes, Hanieh Mazloom Farsibaf

Physics & Astronomy ETDs

Many experiments have shown that the diffusive motion of lipids and membrane proteins are slower on the cell surface than those in artificial lipid bilayers or blebs. One hypothesis that may partially explain this mystery is the effect of the cytoskeleton structures on the protein dynamics. To test this hypothesis, we designed a high-speed single particle tracking microscope and use a hybrid tracking and super-resolution approach on the same cell. We labeled the high-affinity FceRI receptor as a transmembrane protein and GPI-anchored proteins as an example of outer leaflet protein in Rat Basophilic Leukemia (RBL) cells and tracked these membrane …

Optimizing Measurement Strengths For Qubit Quasiprobabilities Behind Out-Of-Time-Ordered Correlators, Razieh Mohseninia, José Raúl González Alonso, Justin Dressel

Mathematics, Physics, and Computer Science Faculty Articles and Research

Out-of-time-ordered correlators (OTOCs) have been proposed as a tool to witness quantum information scrambling in many-body system dynamics. These correlators can be understood as averages over nonclassical multitime quasiprobability distributions (QPDs). These QPDs have more information and their nonclassical features witness quantum information scrambling in a more nuanced way. However, their high dimensionality and nonclassicality make QPDs challenging to measure experimentally. We focus on the topical case of a many-qubit system and show how to obtain such a QPD in the laboratory using circuits with three and four sequential measurements. Averaging distinct values over the same measured distribution reveals either …

First-Principles Study Of High-Pressure Phase Stability And Superconductivity Of Bi4i4, Shiyu Deng, Xianqi Song, Quan Li, Yu Xie, Changfeng Chen, Yanming Ma

Physics & Astronomy Faculty Research

Bismuth iodide Bi4I4 exhibits intricate crystal structures and topological insulating states that are highly susceptible to influence by environments, making its physical properties highly tunable by external conditions. In this work, we study the evolution of structural and electronic properties of Bi4I4 at high pressure using an advanced structure search method in conjunction with first-principles calculations. Our results indicate that the most stable ambient-pressure monoclinic α−Bi4I4 phase in C2/m symmetry transforms to a trigonal P31c structure (ɛ−Bi4I4) at 8.4 GPa, then to a tetragonal P4/mmm structure (ζ−Bi4I4) above 16.6 GPa. In contrast to the semiconducting nature of ambient-pressure Bi4I4, the …

Protein And Polysaccharide-Based Magnetic Composite Materials For Medical Applications., Elizabeth J Bealer, Kyril Kavetsky, Sierra Dutko, Samuel Lofland, Xiao Hu

College of Science & Mathematics Departmental Research

The combination of protein and polysaccharides with magnetic materials has been implemented in biomedical applications for decades. Proteins such as silk, collagen, and elastin and polysaccharides such as chitosan, cellulose, and alginate have been heavily used in composite biomaterials. The wide diversity in the structure of the materials including their primary monomer/amino acid sequences allow for tunable properties. Various types of these composites are highly regarded due to their biocompatible, thermal, and mechanical properties while retaining their biological characteristics. This review provides information on protein and polysaccharide materials combined with magnetic elements in the biomedical space showcasing the materials used, …

An Analysis Of The Atmospheric Propagation Of Underground-Explosion-Generated Infrasonic Waves Based On The Equations Of Fluid Dynamics: Ground Recordings, Roberto Sabatini, Jonathan B. Snively, Michael P. Hickey, J. L. Garrison

Publications

An investigation on the propagation of underground-explosion-generated infrasonic waves is carried out via numerical simulations of the equations of fluid dynamics. More specifically, the continuity, momentum, and energy conservation equations are solved along with the Herzfeld-Rice equations in order to take into account the effects of vibrational relaxation phenomena. The radiation of acoustic energy by the ground motion caused by underground explosions is initiated by enforcing the equality, at ground level, between the component of the air velocity normal to the Earth's surface and the normal velocity of the ground layer. The velocity of the ground layer is defined semi-empirically …

The Belle Ii Physics Book, E. Kou, P. Urquijo, W. Altmannshofer, F. Beajean, G. Bell, M. Beneke, I. I. Bigi, F. Bishara, M. Blanke, C. Bobeth, M. Bona, N. Brambilla, V. M. Braun, J. Brod, A. J. Buras, H. Y. Cheng, C. W. Chiang, M. Ciuchini, G. Colangelo, Milind Purohit, Et. Al.

Faculty Publications

No abstract provided.

Total Electron Content Prediction Model Using The Artificial Neural Networks Over The Eastern Africa Region, Emmanuel D. Sulungu, Christian B.S. Uiso

Tanzania Journal of Science

In this paper, development of a model using NN technique for prediction of GPS TEC over the Eastern Africa region is presented. TEC data was obtained from the Africa array and IGS network of ground based dual-frequency GPS receivers from 18 stations within the East African region. It covers approximately the area from ~2.6°N to ~26.9°S in magnetic latitudes and from ~95°E to ~112oE in magnetic longitudes. The input layer of the developed model consisted of seven neurons which were selected by considering the parameters that are known to affect the TECv data. The results showed that when the number …

On Scalar Multiples Of Hypercyclic Operators On Non-Normable And Separable Fréchet Spaces, Melkiory M. Aloyce, Santosh Kumar, Marco Mpimbo

Tanzania Journal of Science

In this paper, we proved that if F is a non-normable and separable Fréchet space without a continuous norm, then there exists an operator T L (F) such that λ T is hypercyclic for any λ   {0} of modulus 1 and has similar set of hypercyclic vectors as T. An illustrative example to the main theorem is also provided.

Generation Of Highly Ordered 3d Vivid Monochromatic Coloured Photonic Crystal Films Using Evaporative Induced Technique, Ikhazuagbe H. Ifijen, Esther U. Ikhuoria

Tanzania Journal of Science

Structural coloured crystal films have attracted immense attention because of numerous applications like optical sensing, anti-counterfeiting and photonic fabrics.  Herein, we successfully generated highly periodic three-dimensional (3D) monochromatic structural crystal films with brown, turquoise, blue and yellow colourations from as-synthesized poly(styrene-methyl methacrylate-acrylic acid) or P(St-MMA-AA) colloidal latex via the evaporative induced self-assembly technique. The colours were controlled through the modulation of their crystal lattice by varying their microspheres diameter from 180 nm, 120 nm, and 260 nm to 150 nm. Scanning electron microscope and atomic force microscope (SEM/AFM) analyses showed that the photonic crystal particles readily assembled into an impeccable …

Constraints On Parton Distribution Functions Imposed By Hadronic Experiments, Boting Wang

Physics Theses and Dissertations

The theoretical uncertainties of the Large Hadron Collider (LHC) observables are decreasing with the increasing statistics of the LHC experiments, and it is becoming more and more important to reduce the uncertainties in the knowledge of the nucleon structure. The latest LHC high-energy experiments, future experimental proposals, and computational tools are expected to enhance the knowledge of the nucleon structure. However, the global analysis that assesses their impact on Parton Distribution Functions (PDFs) knowledge is computationally expensive due to the corresponding large size of data. I developed a new approach that can make a quick preliminary evaluation to help the …

Measurement Of The Integrated Luminosity Of The Phase 2 Data Of The Belle Ii Experiment, F. Abudinén, I. Adachi, P. Ahlburg, H. Aihara, N. Akopov, A. Aloisio, F. Ameli, L. Andricek, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, T. Aziz, K. Azmi, V. Babu, S. Baehr, S. Bahinipati, A. M. Bakich, Milind Purohit, Et. Al.

Faculty Publications

From April to July 2018, a data sample at the peak energy of the Υ(4S) resonance was collected with the Belle II detector at the SuperKEKB electron-positron collider. This is the first data sample of the Belle II experiment. Using Bhabha and digamma events, we measure the integrated luminosity of the data sample to be (469.3±0.3±3.0) pb^-1, where the first uncertainty is statistical and the second is systematic. This work provides a basis for future luminosity measurements at Belle II.

Detection Of Whale Acoustic Signals In The Northern Gulf Of Mexico Ladc-Gemm Database, Yingxue Gao

LSU New Orleans Theses and Dissertations

Low-pass Fourier filter, wavelet filter, as well as matched filter detection methods were used to detect baleen whale signals in northern Gulf of Mexico data collected by the Littoral Acoustic Demonstration Center (LADC) consortium. Some potential low frequency signals appeared on the matched filter output figure. The shape of the signals is in line with one of the typical signal shapes of fin whales--vertical down-sweeps with 18s-time interval. Another shape of the signals is in line with one of the call type shapes of Bryde's whales--down-sweeps with 7s-time interval. A high-pass Fourier filter was also used to find toothed whale …

Vertical Acoustic Propagation In The Non-Homogeneous Layered Atmosphere For A Time-Harmonic, Compact Source, Edward J. Yoerger Jr

LSU New Orleans Theses and Dissertations

In this work we study vertical, acoustic propagation in a non-homogeneous media for a spatially-compact, time-harmonic source. An analytical, 2-layer model is developed representing the acoustic pressure disturbance propagating in the atmosphere. The validity of the model spans the distance from the Earth's surface to 30,000 meters. This includes the troposphere (adiabatic), ozone layer (isothermal), and part of the stratosphere (isothermal). The results of the model derivation in the adiabatic region yield pressure solutions as Bessel functions of the First (J) and Second (Y) Kind of order $-\frac{7}{2}$ with an argument of $2 \Omega \tau$ (where $\Omega$ represents a dimensionless …

Exploratory Measurements Of Large Winds And Shears In The Lower Thermosphere And Their Variability Using An Enhanced Sodium Lidar, Tao Yuan

Funded Research Records

No abstract provided.

Development Of A Low-Cost, Open Source Miniature Rotary Cell Culture System To Simulate Microgravity Within An Irradiated Environment, Elizabeth Vargis, Jr Dennison

Browse all Datasets

A major challenge for astronauts in long-duration space travel is combatting the hazardous spaceflight environment caused by microgravity and increased levels of ionizing radiation. Microgravity damages cellular DNA by increasing the production of harmful reactive oxygen species, while ionizing radiation damages DNA by creating double-stranded DNA (dsDNA) breaks. Cellular damage due to microgravity and radiation has been investigated using ground-based models, but most models consider microgravity and ionizing radiation alone, or asynchronously. Synchronous modeling better mimics spaceflight conditions and can be used to understand the combined effects of microgravity and ionizing radiation. However, commercially available devices to model microgravity and …

Is Contact Nucleation Caused By Pressure Perturbation?, Fan Yang, Will Cantrell, Alexander Kostinski, Raymond Shaw, Andrew M. Vogelmann

Michigan Tech Publications, Part 1

The reason why ice nucleation is more efficient by contact nucleation than by immersion nucleation has been elusive for over half a century. Six proposed mechanisms are summarized in this study. Among them, the pressure perturbation hypothesis, which arose from recent experiments, can qualitatively explain nearly all existing results relevant to contact nucleation. To explore the plausibility of this hypothesis in a more quantitative fashion and to guide future investigations, this study assessed the magnitude of pressure perturbation needed to cause contact nucleation and the associated spatial scales. The pressure perturbations needed were estimated using measured contact nucleation efficiencies for …

Analytic Non-Adiabatic Derivative Coupling Terms For Spin-Orbit Mrci Wavefunctions. I. Formalism, Lachlan T. Belcher, Gary S. Kedziora, David E. Weeks

Faculty Publications

Analytic gradients of electronic eigenvalues require one calculation per nuclear geometry, compared to at least 3n + 1 calculations for finite difference methods, where n is the number of nuclei. Analytic nonadiabatic derivative coupling terms (DCTs), which are calculated in a similar fashion, are used to remove nondiagonal contributions to the kinetic energy operator, leading to more accurate nuclear dynamics calculations than those that employ the Born-Oppenheimer approximation, i.e., that assume off-diagonal contributions are zero. The current methods and underpinnings for calculating both of these quantities, gradients and DCTs, for the State-Averaged MultiReference Configuration Interaction with Singles and Doubles (MRCI-SD) …

Cyclotron Resonance In Graphene Heterostructurescyclotron Resonance In Graphene Heterostructures, Billy Jordan Russell

Arts & Sciences Graduate Student Theses and Dissertations

We present observations of cyclotron resonance in graphene Van der Waals heterostructure devices. Such devices provide dramatic improvements in sample quality and allow for ad- vanced electronic control, opening windows on previously inaccessible physics. The design and construction of a dedicated system for the measurement of electronic transport and infrared magnetospectroscopy in microscopic samples of atomically thin materials at cryogenic temperatures is presented. In high-mobility encapsulated monolayer graphene, electron- electron interaction effects are unambiguously observed to impact the interband cyclotron resonance as the Landau level filling factor is varied in a quantizing magnetic field. Additionally, a splitting of transitions involving …