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Articles 1 - 30 of 1851
Full-Text Articles in Physics
High-Speed Data Communications For Vehicular Networks Using Free-Space Optical Communications, Yagiz Kaymak
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
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 …
Table Of Contents
Journal of the South Carolina Academy of Science
No abstract provided.
Application Of Graphical Models In Protein-Protein Interactions And Dynamics, Amir Vajdi Hoojghan
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 …
The Role Of Friction In The Static Equilibrium Of A Fixed Ladder: Theoretical Analysis And Experimental Test, Mark P. Silverman
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
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 …
Transient Transmission Oscillations In Doped And Undoped Lithium Niobate Induced By Near-Infrared Femtosecond Pulses, Bryan J. Crossman, Gregory J. Taft
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 …
Evidence For Terahertz Acoustic Phonon Parametric Oscillator Based On Acousto-Optic Degenerate Four-Wave Mixing In A Silicon Doping Superlattice, Thomas E. Wilson
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
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
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.
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− …
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
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
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
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
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 DLL 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 DLL 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 pT 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.
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
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
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
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
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
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 …
Electrical Characterization Of Crystalline Uo2, Tho2 And U0.71Th0.29O2, Christina L. Dugan
Electrical Characterization Of Crystalline Uo2, Tho2 And U0.71Th0.29O2, Christina L. Dugan
Theses and Dissertations
Uranium dioxide (UO2), thorium dioxide (ThO2), and UxTh1-xO2 alloys are characterized for suitability in uranium-based neutron detectors. ThO2 was studied for an envisioned UO2/ThO2 heterojunction. A U0.71Th0.29O2 alloy was studied because of its resistance to oxidation and potential use in surface passivation. The U0.71Th0.29O2 effective Debye temperature of 217± 24 K was measured using temperature-dependent x-ray photoemission spectroscopy (XPS). The specific heat capacity for the U0.71Th0.29O2 alloy was calculated from the Debye …
Optical Micro-Seismometer Based On Evanescent Field Perturbation Of Whispering Gallery Modes, Jaime Da Silva
Optical Micro-Seismometer Based On Evanescent Field Perturbation Of Whispering Gallery Modes, Jaime Da Silva
Mechanical Engineering Research Theses and Dissertations
This thesis proposes a light-weight, compact, and accurate optical micro-seismometer that could be used in many applications, such as planetary exploration. The sensor proposed here is based on the principle of whispering gallery optical mode (WGM) resonance shifts of a dielectric micro-resonator due to disturbances of its evanescent field. The micro-seismometer could be used in place of the traditional bulky seismometers. The design of a waveguide-resonator and mechanical structure to disturb the evanescent field are presented. A proof-of-concept a seismometer model that uses a 5µm ring resonator is numerically tested with actual seismic data. The results show that a WGM-based …
Studies Of Inner-Shell Chemistry Of Mercury Based Compounds At Extreme Conditions, Sarah Schyck
Studies Of Inner-Shell Chemistry Of Mercury Based Compounds At Extreme Conditions, Sarah Schyck
UNLV Theses, Dissertations, Professional Papers, and Capstones
It has been theoretically predicted that when mercury difluoride (HgF2) is pressurized to above 50 GPa in the presence of molecular fluorine, it will most likely transform into mercury tetrafluoride (HgF4), thus mercury will behave as a transition element at high pressure. However, there is no experimental evidence verifying this prediction yet. To begin with, the crystalline properties of pure HgF2 at high pressure were not experimentally established. In this thesis, the high pressure structural properties of HgF2 are investigated by means of synchrotron X-ray powder diffraction. Our results reveal that the predicted, ambient cubic structure of HgF2 with the …
Bayesian Model Comparisons In Planetary Science, John Henry Boisvert
Bayesian Model Comparisons In Planetary Science, John Henry Boisvert
UNLV Theses, Dissertations, Professional Papers, and Capstones
Model comparison in the modern era allows us to use statistical methods that were previously difficult with older machines. I present a state-of-the-art model comparison code that uses modern Bayesian statistics to measure the Bayes factor between two competing models. The Bayes factor is the ratio of the probability of the data given one model to the probability of the data given another model. My code was used to compare models in five problems in planetary science. The first three pertain to radial velocity exoplanet data. There is a degeneracy in the radial velocity exoplanet signal between a single planet …
Design, Layout, And Testing Of Sige Apds Fabricated In A Bicmos Process, Dane Laurence Gentry
Design, Layout, And Testing Of Sige Apds Fabricated In A Bicmos Process, Dane Laurence Gentry
UNLV Theses, Dissertations, Professional Papers, and Capstones
This Thesis is concerned with the design, layout, and testing of avalanche photodiodes (APDs). APDs are a type of photodetector and, thus, convert light signals into electrical signals (current or voltage). APDs can be fabricated using silicon (Si). In this Thesis, however, three integrated circuit (IC) chips containing various silicon-germanium (SiGe) APDs with different sizes, structures, and geometries were designed, laid out, and fabricated using the Austriamicrosystems (AMS) 0.35μm SiGe BiCMOS (S35) process. This was done in order to compare SiGe APDs to Si only APDs and investigate the hypothesis that SiGe APDs are capable of detecting longer wavelengths than …
Optimization Of Useful Hard X-Ray Photochemistry, David Lewis Goldberger
Optimization Of Useful Hard X-Ray Photochemistry, David Lewis Goldberger
UNLV Theses, Dissertations, Professional Papers, and Capstones
X-ray induced damage is generally considered a nuisance, but in the field of Useful Hard X-ray Photochemistry we harness the highly ionizing and penetrating properties of hard X-rays (> 7 keV) to initiate novel photochemical decomposition and synthesis at ambient and extreme conditions. Preliminary experiments suggest that the energy of irradiating photons and the sample pressure play roles in determining the nature of X-ray induced damage. Here, we present the X-ray energy dependence of damage induced in strontium oxalate, strontium nitrate, and barium nitrate, as well as the pressure dependence of X-ray induced damage of strontium oxalate. Our results indicate …
Fast Objective Coupled Planar Illumination Microscopy, Cody Jonathan Greer
Fast Objective Coupled Planar Illumination Microscopy, Cody Jonathan Greer
Arts & Sciences Electronic Theses and Dissertations
Among optical imaging techniques light sheet fluorescence microscopy stands out as one of the most attractive for capturing high-speed biological dynamics unfolding in three dimensions. The technique is potentially millions of times faster than point-scanning techniques such as two-photon microscopy. This potential is especially poignant for neuroscience applications due to the fact that interactions between neurons transpire over mere milliseconds within tissue volumes spanning hundreds of cubic microns. However current-generation light sheet microscopes are limited by volume scanning rate and/or camera frame rate. We begin by reviewing the optical principles underlying light sheet fluorescence microscopy and the origin of these …
Tunable Electronic And Optical Properties Of Low-Dimensional Materials, Shiyuan Gao
Tunable Electronic And Optical Properties Of Low-Dimensional Materials, Shiyuan Gao
Arts & Sciences Electronic Theses and Dissertations
Two-dimensional (2D) materials with single or a few atomic layers, such as graphene, hexagonal boron nitride (h-BN) and transition metal dichalcogenides (TMDCs), and the heterostructures or one-dimensional (1D) nanostructures they form, have attracted much attention recently as unique platforms for studying many condensed-matter phenomena and holds great potentials for nanoelectronics and optoelectronic applications. Apart from their unique intrinsic properties which has been intensively studied for over a decade by now, they also allow external control of many degrees of freedom, such as electrical gating, doping and layer stacking. In this thesis, I present a theoretical study of the electronic and …
Linking Structure And Dynamics In Metallic Liquids: A Combined Experimental And Molecular Dynamics Approach, Robert Ashcraft
Linking Structure And Dynamics In Metallic Liquids: A Combined Experimental And Molecular Dynamics Approach, Robert Ashcraft
Arts & Sciences Electronic Theses and Dissertations
A major outstanding problem in condensed matter physics is the nature of the glass transition, in which a rapidly cooled liquid can bypass the transition into a crystalline state and the liquid structure is "frozen-in" due to kinetic arrest. To characterize the fundamental features behind this transition the liquid, both in the high temperature (equilibrium) and supercooled state, needs to be better understood. By examining the relationship between structure and dynamics a better characterization of the liquid state and a determination of the mechanisms that are ultimately important for the formation of the glass can be gained. In this dissertation, …