Digital Commons Network^™

High-Speed Data Communications For Vehicular Networks Using Free-Space Optical Communications, Yagiz Kaymak

Dissertations

The demand for high-speed Internet access for vehicles, such as high-speed trains (HSTs) and cars, is on the rise. Several Internet access technologies that use radio frequency are being considered for vehicular networking. Radio-frequency communications technologies cannot provide high data rates due to interference, bandwidth limitations, and the inherent limited data rates of radio technology. Free-space optical communications (FSOC) is an alternative approach and a line-of-sight (LOS) technology that uses modulated light to transfer data between two free-space optical (FSO) transceivers. FSOC systems for vehicular networks are expected to provide data rates in the range of Gbps for stationary and …

Fwer Controlling Procedures In Simultaneous And Selective Inference, Li Yu

Dissertations

With increasing complexity of research objectives in clinical trials, a variety of relatively complex and less intuitive multiple testing procedures (MTPs) have been developed and applied in clinical data analysis. In order to make testing strategies more explicit and intuitive to communicate with non-statisticians, several flexible and powerful graphical approaches have recently been introduced in the literature for developing and visualizing newer MTPs. Nevertheless, some theoretical as well as methodological issues still remain to be fully addressed. This dissertation addresses several important issues arising in graphical approaches and related selective inference problems. It consists of three parts.

In the first …

Application Of Graphical Models In Protein-Protein Interactions And Dynamics, Amir Vajdi Hoojghan

Graduate Doctoral Dissertations

Every organism contains a few hundred to thousands of proteins. A protein is made of a sequence of molecular building blocks named amino acids. Amino acids will be referred to as residues. Every protein performs one or more functions in the cell. In order for a protein to do its job, it requires to bind properly to other partner proteins. Many genetic diseases such as cancer are caused by mutations (changes) of specific residues which cause disturbances in the functions of those proteins.

The problem of prediction of protein binding site is a crucial topic in computational biology. A protein …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

The Role Of Friction In The Static Equilibrium Of A Fixed Ladder: Theoretical Analysis And Experimental Test, Mark P. Silverman

Faculty Scholarship

In a recent publication the author derived and experimentally tested several theoretical models, distinguished by different boundary conditions at the contacts with horizontal and vertical supports, that predicted the forces of reaction on a fixed (i.e. inextensible) ladder. This problem is statically indeterminate since there are 4 forces of reaction and only 3 equations of static equilibrium. The model that predicted the empirical reactions correctly used a law of static friction to complement the equations of static equilibrium. The present paper examines in greater theoretical and experimental detail the role of friction in accounting for the forces of reaction on …

Detrital Zircon Geochronology And Evolution Of The Nacimiento Block Late Mesozoic Forearc Basin, Central California Coast, Scott Johnston, Andrew R.C. Kylander-Clark, Alan D. Chapman

Physics

Forearc basins are first-order products of convergent-margin tectonics, and their sedimentary deposits offer unique perspectives on coeval evolution of adjacent arcs and subduction complexes. New detrital zircon U-Pb geochronologic data from 23 sandstones and 11 individual conglomerate clasts sampled from forearc basin strata of the Nacimiento block, an enigmatic stretch of the Cordilleran forearc exposed along the central California coast, place constraints on models for forearc deformation during evolution of the archetypical Cordilleran Mesozoic margin. Deposition and provenance of the Nacimiento forearc developed in three stages: (1) Late Jurassic– Valanginian deposition of lower Nacimiento forearc strata with zircon derived from …

Evidence For Terahertz Acoustic Phonon Parametric Oscillator Based On Acousto-Optic Degenerate Four-Wave Mixing In A Silicon Doping Superlattice, Thomas E. Wilson

Physics Faculty Research

We report evidence for a 1.0-THz self-starting mirrorless acoustic phonon parametric oscillator (MAPPO) produced from acousto-optic phase-conjugate degenerate four-wave (D4WM) mixing in a THz laser-pumped silicon doping superlattice (DSL). The DSL was grown by molecular beam epitaxy on a (100) boron-doped silicon substrate. A superconducting NbTiN subwavelength grating was used to couple the THz laser radiation into the DSL. Superconducting granular aluminum bolometric detection, coupled with Si:B piezophonon spectroscopy, revealed excitation of THz coherent compressional and shear waves, along the ⟨111⟩ direction only. The Bragg scattering condition for distributed feedback, and the energy conservation requirement for the D4WM process, were …

Decays Of Pentaquarks In Hadrocharmonium And Molecular Scenarios, Michael I. Eides, Victor Yu. Petrov

Physics and Astronomy Faculty Publications

We consider decays of the hidden charm LHCb pentaquarks in the hadrocharmonium and molecular scenarios. In both pictures the LHCb pentaquarks are essentially nonrelativistic bound states. We develop a semirelativistic framework for calculation of the partial decay widths that allows the final particles to be relativistic. Using this approach we calculate the decay widths in the hadrocharmonium and molecular pictures. Molecular hidden charm pentaquarks are constructed as loosely bound states of charmed and anticharmed hadrons. Calculations show that molecular pentaquarks decay predominantly into states with open charm. Strong suppression of the molecular pentaquark decays into states with hidden charm is …

First-Principles Investigation Of Sc-Iii/Iv Under High Pressure, Sheng-Cai Zhu, Xiao-Zhi Yan, Scott Fredericks, Yan-Ling Li, Qiang Zhu

Physics & Astronomy Faculty Research

Using an ab initio evolutionary structure prediction method in conjunction with density functional theory, we performed a systematic investigation of the structural transition of elemental scandium under pressure up to 250 GPa. Our prediction successfully reproduced several allotropes which have been reported in the literature, including the Sc-I, Sc-II, and Sc-V. Moreover, we observed a series of energetically degenerate and geometrically similar structures at 110–195 GPa, which can partly explain the experimental observations regarding the unsolved phases III and IV reported by Y. Akahama et al. [Phys. Rev. Lett. 94, 195503 (2005)]. A detailed comparison of the powder x-ray diffraction …

Study Of The Reactions E+E-→Π+Π-Π0Π0Π0 And Π+Π-Π0Π0Η At Center-Of-Mass Energies From Threshold To 4.35 Gev Using Initial-State Radiation, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, D. N. Brown, Yu G. Kolomensky, M. Fritsch, H. Koch, T. Schroeder, C. Hearty, T. S. Mattison, J. A. Mckenna, R. Y. So, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, V. B. Golubev, E. A. Kozyrev, Milind Purohit, Et. Al.

Faculty Publications

We study the processes e⁺e⁻ → π⁺π⁻π⁰π⁰π⁰nγ in which an energetic photon is radiated from the initial state. The data are collected with the BABAR detector at SLAC. About 14 000 and 4700 events, respectively, are selected from a data sample corresponding to an integrated luminosity of 469 fb⁻¹. The invariant mass of the hadronic final state defines the effective e⁺e⁻ center-of-mass energy. From the mass spectra, the first precise measurement of the e⁺e⁻ → π⁺π^{− …}

Transient Transmission Oscillations In Doped And Undoped Lithium Niobate Induced By Near-Infrared Femtosecond Pulses, Bryan J. Crossman, Gregory J. Taft

Physics Faculty Publications

Transient transmission oscillations in X-cut and Z-cut congruent, iron-doped, and magnesium-doped lithium niobate samples were measured using 50 fs, 800 nm, 0.5 nJ pulses from a self-mode-locked Ti:sapphire laser in an optical pump–probe system. Several Raman-active oscillation modes excited by these pulses were observed as changes in the transmitted probe intensity versus time delay between the pump and probe pulses. The samples were rotated to determine how the incident polarization of the pump pulses affects the mode excitations. The observed Raman-active oscillations correspond to previously reported symmetry modes measured with traditional, continuous-wave, Raman spectroscopy using the same scattering …

System And Process Of Thermal Neutron Flux Producing By Means Of An Accelerator Base Electron Of 18 Mev, A. Didi, A. Dadouch, H. El Bekkour, O. Jai, F. Bouhal, M. Bencheikh

Eurasian Journal of Physics and Functional Materials

Neutrons are produced in accelerators by irradiating heavy targets with an electron or proton beam. Produced neutrons are of high energy. The purpose of our work is optimization the neutron flux by MCNP-6 code for production the thermal neutron flux using a moderator and for convertation the fast neutron flux into a thermal neutron flux. In this article, we are interested in a thermal neutron flux due it is useful for method of neutron activation analysis. In conventional sources, the moderator is usually a large volume of water or paraffin around the source. Initially, fast neutrons have energy above 1 …

Structure Study Of Al+Al2o3 Composite By Atomic Force Microscopy, D. S. Koleukh, A. S. Kaygorodov, S. V. Zayats, S. N. Paranin

Eurasian Journal of Physics and Functional Materials

The structure of a metal matrix composite based on aluminum containing 6, 17 and 24 wt % Al² O³ was studied by atomic force microscopy. The composite was prepared by the method of magneticpulse compaction from aluminum nanopowder obtained by the electric wire explosion method. The samples compacted at 400 ◦ C have more clearly expressed grain boundaries than those obtained at room temperature. The structure of a composite subjected to dynamic plastic deformation is studied.

Synthesis And Investigation Of Optical Properties Of Cdse Quantum Dots With High Quantum Luminescence Yield, A. Z. Kainarbay, T. N. Nurakhmetov, Z. M. Salikhodja, A. M. Zhunusbekov, D. K. Daurenbekov, B. Sadykova, B. Yussupbekova, K. Zhanylysov, A. Kainarbayeva, N. Adalbek, N. Shaken, A. Turmakhanbetova, K. N. Balabekov

Eurasian Journal of Physics and Functional Materials

In the present work, an attempt to obtain quantum dots with a high quantum luminescence yield has been made. For this purpose, the existing methods of synthesis have been studied; approbation of availability and reproducibility of the results and possibility of obtaining luminescent QD samples in the required spectral region has been made. The optical characteristics, the influence of the synthesis conditions, the possibility of using nanostructured materials for sensitization of solar cells have been studied.

Some Radiation Effects In Ii-Vi Quantum Dots, M. B. Sharibaev, Q. A. Ismailov

Eurasian Journal of Physics and Functional Materials

The effect of electron irradiation (E=0.6-1.8 MeV) on the optical characteristics (photoluminescence, PL) of CdTe/ZnTe structures with quantum dots, QDs, was investigated in the temperature range from 4.2 to 250 K. The data on the influence of irradiation on the temperature dependence of PL intensity, energy position and PL line width, W, from QDs were obtained. The narrowing of PL band and the blue shift of the QD peak position are explained by quenching of the low energy component connected with larger QDs. A slight decrease in PL intensity for both QDs and the buffer ZnTe layer as well as …

Influence Of Structural Defects In Silicon On Formation Of Photosensitive Heterostructures Mn4si7-Si-Mn4si7 And Mn4si7-Si-M, T. S. Kamilov, A. S. Rysbaev, V. V. Klechkovskaya, A. S. Orekhov, Sh. Kh. Dzhuraev, A. S. Kasymov

Eurasian Journal of Physics and Functional Materials

The paper considers the influence of a transition amorphous layer at the interface between the higher manganese silicide (HMS) Mn ₄ Si ₇ and silicon doped with manganese (Si ) on the photoelectric properties of heterostructures. The role of the initial structural defects in the near-surface layers of the single-crystal silicon on the penetration of manganese atoms into Si upon doping from the gas phase is shown.It has been established that at high temperatures (T>1050 ◦ C) Mn atoms deposited on the silicon surface group together (due to surface diffusion), forming droplets of liquid manganese, which dissolve the near-surface …

Development Of Thermal Sensors By Implantation Ions P+ And B+ In Different Sides Of Si(111), I. R. Bekpulatov, A. S. Rysbaev, Sh. Kh. Dzhuraev, A. S. Kasymov

Eurasian Journal of Physics and Functional Materials

In the method of high-phase ion implantation of P ⁺ and B ⁺ to different sides of monocrystal silicon we obtained p-i-n- structure, which has a high thermal sensitivity of 2.3 mV/K in a broad band temperature of (20 ÷ 550) K. We studied the distribution profile P and B atoms implanted in the Si gradually decreasing energy. The effect of the subsequent thermal and annealing IR profile on the distribution of the atoms and the characteristics of the temperature sensor was studied.

New Mocd2 Phase In Film Coatings Of Molybdenum-Cadmium System, Yu. Zh. Tuleushev, V. N. Volodin, Y. A. Zhakanbaev

Eurasian Journal of Physics and Functional Materials

Ion-plasma sputtering and code position of Mo and Cd ultrafine particles have been used for the first time to prepare solid solutions that are alloys with a concentration up to 57.3 at. % Cd in the film; this confirms the thermal-fluctuation and coalescence of small particles. When coatings are formed by molyb-denum and cadmium nanolayers less than 2 nm in the concentrations range of 60-66 at. % Cd, a new phase was found that was prepared directly in the course of film coating formation; it was identified as the MoCd₂ compound with a tetragonal face-centered lattice, with the parameters …

Different Methods Of Correcting The Readings Of The Dvgn-01 Albedo Neutron Dosimeter Placed Behind The Ibr-2m Protection, Yu. V. Mokrov, S. V. Morozova, G. N. Timoshenko, V. A. Krylov, O. B. Badunov, G. A. Seilkhanova

Eurasian Journal of Physics and Functional Materials

The paper presents the results of correction of readings of DVBN-01 albedo dosimeters behind IBR-2M protection, the Neutron Physics Laboratory of the Joint Institute for Nuclear Research (JINR), Dubna, byvarious methods. The neutron spectra were measured at two points behind the IBR-2M protection in the experimental halls, and measurements were carried out with the spherical albedo system at these points. The correction coefficients for DVGN-01 were calculated from the measured spectra based on the data of the spherical albedo system. A good agreement of the coefficients calculated by different methods is shown, which indicates the reliability of the obtained values …

Analysis Of (11li+9be)-Reaction In The Framework Of The Time-Dependent Schrodinger Equation, A. K. Azhibekov, K. A. Kuterbekov, V. V. Samarin

Eurasian Journal of Physics and Functional Materials

Neutron transfer and nucleus breakup cross sections in (¹¹Li + ⁹Be) -reaction are calculated at energy range up to 32 MeV/nucleon. The evolution of probability density of external weakly bound neutrons of 11Li and the probabilities of neutron transfer and nucleus breakup are determined based on a numerical solution of the time-dependent Schrodinger equation. Our calculation results are agree with the experiment.

Improved Measurement Of The Longitudinal Spin Transfer To Λ And Bar(Λ) Hyperons In Polarized Proton-Proton Collisions At Sqrt(S) = 200 Gev, James Drachenberg

Engineering and Physics

No abstract provided.

Single-Crystal Investigation Of The Proposed Type-Ii Weyl Semimetal Cealge, Halyna Hodovanets, C. J. Eckberg, P. Y. Zavalij, Hyunsoo Kim, W. C. Lin, M. Zic, D. J. Campbell, J. S. Higgins, J. Paglione

Physics Faculty Research & Creative Works

We present details of materials synthesis, crystal structure, and anisotropic magnetic properties of single crystals of CeAlGe, a proposed type-II Weyl semimetal. Single-crystal x-ray diffraction confirms that CeAlGe forms in a noncentrosymmetric I4₁md space group, in line with predictions of nontrivial topology. Magnetization, specific heat, and electrical transport measurements were used to confirm antiferromagnetic order below 5 K, with an estimated magnon excitation gap of Δ = 9.11 K from heat capacity and hole-like carrier density of 1.4 x 10²⁰ cm^-3 from Hall effect measurements. The easy magnetic axis is along the [100] crystallographic direction, indicating …

Geologic Map And Structural Development Of The Noerthernmost Sur-Nacimiento Fault Zone, Central California Coast, Scott M. Johnston, John S. Singleton, Alan D. Chapman, Gabriella Murray

Physics

The Sur-Nacimiento fault exposed along the central California coast (United States) juxtaposes the Salinian block arc against the Nacimiento block accretionary complex, cuts out the majority of the forearc basin and western arc, and requires a minimum of 150 km of orogen-normal crustal excision within the Mesozoic California convergent margin. Despite this significant strain, the kinematic evolution of the Sur-Nacimiento fault remains poorly understood, with diverse hypotheses suggesting sinistral, dextral, thrust, or normal displacement along the fault. This Late Cretaceous–Paleogene strain history is complicated by the location of the fault within a belt of subparallel faults that have accommodated significant …

Improved Measurement Of The Longitudinal Spin Transfer To Λ And Λ¯ Hyperons In Polarized Proton-Proton Collisions At √S = 200 Gev, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. D. Brandenburg, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

The longitudinal spin transfer D_LL to Λ and Λ¯ hyperons produced in high-energy polarized proton-proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and antiquarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of D_LL from data obtained at a center-of-mass energy of √s = 200  GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure of merit than prior results and cover |η| < 1.2 in pseudorapidity with transverse momenta p_T up to 6  GeV/c. In the forward scattering hemisphere …

Measurement Of The Branching Fraction And Time-Dependent Cp Asymmetry For B0→J/Ψπ0 Decays, B. Pal, A.J. Schwartz, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, R. Ayad, I. Badhrees, S. Bahinipati, V. Bansal, P. Behera, C. Beleño, B. Bhuyan, T. Bilka, J. Biswal, A. Bozek, M. Bračko, L. Cao, Milind Purohit, Et. Al.

Faculty Publications

We measure the branching fraction and time-dependent CP-violating asymmetry for B0 → J=ψπ0 decays using a data sample of 711 fb⁻¹ collected on the ϒ(4S) resonance by the Belle experiment running at the KEKB e⁺e⁻ collider. The branching fraction is measured to be B(B⁰ → J/_ψπ⁰) ¼ [1.62 ± 0.11(stat) ± 0.06(syst) × 10⁻⁵, which is the most precise measurement to date. The measured CP asymmetry parameters are S =−0.59 ±0.19(stat) 0.03(syst) and A = −0.15 ± 0.14(stat) ^+0.04 _−0.03 (syst). The mixing-induced CP asymmetry (S) differs …

The Propagation Of Active-Passive Interfaces In Bacterial Swarms, Alison E. Patteson, Arvind Gopinath, Paulo E. Arratia

Physics - All Scholarship

Propagating interfaces are ubiquitous in nature, underlying instabilities and pattern formation in biology and material science. Physical principles governing interface growth are well understood in passive settings; however, our understanding of interfaces in active systems is still in its infancy. Here, we study the evolution of an active-passive interface using a model active matter system, bacterial swarms. We use ultra-violet light exposure to create compact domains of passive bacteria within Serratia marcescens swarms, thereby creating interfaces separating motile and immotile cells. Post-exposure, the boundary re-shapes and erodes due to self-emergent collective flows. We demonstrate that the active-passive boundary acts as …

Singularity Resolution In Anisotropic And Black Hole Spacetimes In Loop Quantum Cosmology, Sahil Saini

LSU Doctoral Dissertations

Loop quantum cosmology (LQC) has in recent years led to successful resolution of singularities in cosmological models while agreeing with general relativity in low curvature limit. Existence of a bounce and the possibility of an effective continuum description closely approximating the quantum evolution have been notable features of this singularity resolution. The effective spacetimes of loop quantized isotropic and Bianchi-I models have been shown to be geodesically complete and free from strong singularities. In this dissertation, we extend these results to effective loop quantized Bianchi-II, Bianchi-IX and Kantowski--Sachs models with arbitrary minimally coupled matter, and also explore the possibility of …

Theoretical Studies Of Ultrafast Electron Dynamics In Atoms And Molecules Via High-Order Harmonic Generation, Paul Abanador

Paul Abanador

Mass-Analyzed Threshold Ionization Of Lanthanide Imide Lnnh (Ln = La And Ce) Radicals From N–H Bond Activation Of Ammonia, Yuchen Zhang, Silver Nyambo, Dong-Sheng Yang

Chemistry Faculty Publications

Ln (Ln = La and Ce) atom reactions with ammonia are carried out in a pulsed laser vaporization supersonic molecular beam source. Lanthanide-containing species are observed with time-of-flight mass spectrometry, and LnNH molecules are characterized by mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical calculations. The theoretical calculations include density functional theory for both Ln species and a scalar relativity correction, electron correlation, and spin-orbit coupling for the Ce species. The MATI spectrum of LaNH exhibits a single vibronic band system with a strong origin band and two weak vibronic progressions, whereas the spectrum of CeNH displays two band systems …

Boundary Twists, Instabilities, And Creation Of Skyrmions And Antiskyrmions, Aldo Raeliarijaona, Rabindra Nepal, Alexey Kovalev

Department of Physics and Astronomy: Faculty Publications

We formulate and study the general boundary conditions dictating the magnetization profile in the vicinity of an interface between magnets with dissimilar properties. Boundary twists in the vicinity of an edge due to Dzyaloshinskii-Moriya interactions have been first discussed by Wilson et al. [Phys. Rev. B 88, 214420 (2013)] and by Rohart and Thiaville [Phys. Rev. B 88, 184422 (2013)]. We show that in general case the boundary conditions lead to the magnetization profile corresponding to the Néel, Bloch, or intermediate twist. We explore how such twists can be utilized for creation of skyrmions and antiskyrmions, e.g., in a view …