Public Exposure To U.S. Commercial Nuclear Power Plants Induced Disasters,
2015
The University of Texas Rio Grande Valley
Public Exposure To U.S. Commercial Nuclear Power Plants Induced Disasters, Dean Kyne
Sociology Faculty Publications and Presentations
This study explores the potential risks associated with the 65 U.S.-based commercial nuclear power plants and the distribution of those risks among the populations of both their respective host communities and of the communities located in outlying areas. First, it starts by examining the racial/ethnic composition of the host community populations, as well as the disparities in socioeconomic status that exist, if any, between the host communities and communities located in outlying areas. Second, it utilizes two independent-sample T tests to identify any differences in the sociodemographic compositions of the two areas. Third, it explores regional demographic trends by looking …
Longitudinal Target-Spin Asymmetries For Deeply Virtual Compton Scattering,
2015
Old Dominion University
Longitudinal Target-Spin Asymmetries For Deeply Virtual Compton Scattering, E. Seder, A. Biselli, S. Bültmann, A. Klein, S. E. Kuhn, Y. Prok, Clas Collaboration
Physics Faculty Publications
A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for e p → e'p'ɣ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t, and ɸ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into …
Beam Dynamics Studies Of 499 Mhz Superconducting Rf-Dipole Deflecting Cavity System,
2015
Old Dominion University
Beam Dynamics Studies Of 499 Mhz Superconducting Rf-Dipole Deflecting Cavity System, S. U. De Silva, K. E. Deitrick, H. Park, J. R. Delayen
Physics Faculty Publications
A 499 MHz deflecting cavity has been designed as a three-way beam spreader to separate an electron beam into 3 beams. The rf tests carried out on the superconducting rf-dipole cavity have demonstrated that a transverse voltage of 4.2 MV can be achieved with a single cavity. This paper discusses the beam dynamics on a deflecting structure operating in continuous-wave mode with a relativistic beam. The study includes the analysis on emittance growth, energy spread, and change in bunch size including effects due to field non-uniformities.
Λλ Correlation Function In Au + Au Collisions At √S(Nn)=200 Gev,
2015
Old Dominion University
Λλ Correlation Function In Au + Au Collisions At √S(Nn)=200 Gev, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, S. Bültmann, I. Koralt
Physics Faculty Publications
We present ΛΛ correlation measurements in heavy-ion collisions for Au + Au collisions at √sNN = 200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednicky-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.
Phenomenology Of A Toy Model Inspired By The Spontaneous Reduction Of The Spectral Dimension In Quantum Gravity,
2015
University of New Hampshire, Durham
Phenomenology Of A Toy Model Inspired By The Spontaneous Reduction Of The Spectral Dimension In Quantum Gravity, Patrick A. Greene
Honors Theses and Capstones
Attempts to formulate a quantum theory of gravity have generated many sophisticated models. Though fundamentally different, they necessarily exhibit behaviors resembling experimental observations and standard theoretical expectations. Often, their similarities go no further. However many models unexpectedly predict a change in the spectral dimension of spacetime at very small scales (See [1] and references therein for examples). In particular, some of the models predict the spectral dimension changes from 4 to 2. This paper investigates the phenomenological consequences of a toy model that use Planck-scale 2D hypersurfaces, specifically triangles, embedded in 4D Minkowski spacetime. We randomly generated sequences of triangles …
Tunable Monoenergetic Electron Beams From Independently Controllable Laser-Wakefield Acceleration And Injection,
2015
University of Nebraska-Lincoln
Tunable Monoenergetic Electron Beams From Independently Controllable Laser-Wakefield Acceleration And Injection, Grigory V. Golovin, Shouyuan Chen, Nathan D. Powers, Cheng Liu, Sudeep Banerjee, J Zhang, M Zeng, Z Sheng, Donald P. Umstadter
Donald Umstadter Publications
We report the results of experiments on laser-wakefield acceleration in a novel two-stage gas target with independently adjustable density and atomic-composition profiles.We were able to tailor these profiles in a way that led to the separation of the processes of electron injection and acceleration and permitted independent control of both. This resulted in the generation of stable, quasimonoenergetic electron beams with central energy tunable in 50–300 MeV range. For the first time, we are able to independently control the beam charge and energy spread over the entire tunability range.
Vanadium Oxide Microbolometers With Patterned Gold Black Or Plasmonic Resonant Absorbers,
2015
University of Central Florida
Vanadium Oxide Microbolometers With Patterned Gold Black Or Plasmonic Resonant Absorbers, Evan Smith
Electronic Theses and Dissertations
High sensitivity uncooled microbolometers are necessary to meet the needs of the next generation of infrared detectors, which seek low power consumption and production cost without sacrificing performance. Presented here is the design, fabrication, and characterization of a microbolometer with responsivity enhanced by novel highly absorptive coatings. The device utilizes a gold-doped vanadium oxide film in a standard air bridge design. Performance estimations are calculated from current theory, and efforts to maximize signal to noise ratio are shown and evaluated. Most notably, presented are the experimental results and analysis from the integration of two different absorptive coatings: a patterned gold …
Towards High-Flux Isolated Attosecond Pulses With A 200 Tw Cpa,
2015
University of Central Florida
Towards High-Flux Isolated Attosecond Pulses With A 200 Tw Cpa, Eric Cunningham
Electronic Theses and Dissertations
Attosecond pulses have been developed as a means for investigating phenomena that proceed on the order of the atomic unit of time (24 as). Unfortunately, these extreme ultraviolet (XUV) pulses by themselves contain too few photons to initiate nonlinear dynamics or dress states in an attosecond pump--attosecond probe scheme. As a result, most attosecond experiments thus far have featured complementary near infrared (NIR) femtosecond lasers for instigating electron dynamics. In order to access the benefits of all-attosecond measurements and open attosecond physics to new fields of exploration, the photon flux of these pulses must be increased. One way to boost …
Investigation Of Optical And Electronic Properties Of Au Decorated Mos2,
2015
University of Central Florida
Investigation Of Optical And Electronic Properties Of Au Decorated Mos2, Udai Bhanu
Electronic Theses and Dissertations
Achieving tunability of two dimensional (2D) transition metal dichalcogenides (TMDs) functions calls for the introduction of hybrid 2D materials by means of localized interactions with zero dimensional (0D) materials. A metal-semiconductor interface, as in gold (Au) - molybdenum disulfide (MoS2), is of great interest from the standpoint of fundamental science as it constitutes an outstanding platform to investigate optical and electronic properties due to charge transfer. The applied aspects of such systems introduce new options for electronics, photovoltaics, detectors, catalysis, and biosensing. Here in this dissertation, we study the charge transfer interaction between Au nanoparticals and MoS2 flakes and its …
Nano And Nanostructured Materials For Optical Applications,
2015
University of Central Florida
Nano And Nanostructured Materials For Optical Applications, Panit Chantharasupawong
Electronic Theses and Dissertations
Nano and nanostructured materials offer unique physical and chemical properties that differ considerably from their bulk counterparts. For decades, due to their fascinating properties, they have been extensively explored and found to be beneficial in numerous applications. These materials are key components in many cutting-edge optic and photonic technologies, including photovoltaics, waveguides and sensors. In this dissertation, the uses of nano and nanostructured materials for optical applications are investigated in the context of optical limiting, three dimensional displays, and optical sensing. Nanomaterials with nonlinear optical responses are promising candidates for self-activating optical limiters. In the first part of this study, …
Low Absorption Liquid Crystal Materials For Midwave Infrared,
2015
University of Central Florida
Low Absorption Liquid Crystal Materials For Midwave Infrared, Amy Creekmore
Electronic Theses and Dissertations
Liquid crystal is an amazing class of soft matters with applications spanning from visible, infrared, millimeter wave, to terahertz. In addition to direct-view displays and projection displays, liquid crystal is also widely used in adaptive optics, tunable-focus lens, and laser beam steering. Although the visible region has well developed materials and mixtures for the vast variety of applications, the midwave infrared (MWIR) region of the electromagnetic spectrum invites much development as only a few materials have been developed with these applications in mind. Unlike visible region, the major challenge for mid-wave infrared liquid crystal is inherently large absorption loss. To …
Atmospheric Pressure Chemical Vapor Deposition Of Functional Oxide Materials For Crystalline Silicon Solar Cells,
2015
University of Central Florida
Atmospheric Pressure Chemical Vapor Deposition Of Functional Oxide Materials For Crystalline Silicon Solar Cells, Kristopher Davis
Electronic Theses and Dissertations
Functional oxides are versatile materials that can simultaneously enable efficiency gains and cost reductions in crystalline silicon (c-Si) solar cells. In this work, the deposition of functional oxide materials using atmospheric pressure chemical vapor deposition (APCVD) and the integration of these materials into c-Si solar cells are explored. Specifically, thin oxide films and multi-layer film stacks are utilized for the following purposes: (1) to minimize front surface reflectance without increasing parasitic absorption within the anti-reflection coating(s); (2) to maximize internal back reflectance of rear passivated cells, thereby increasing optical absorption of weakly absorbed long wavelength photons (? > 900 nm); (3) …
Two-Photon Absorption In Bulk Semiconductors And Quantum Well Structures And Its Applications,
2015
University of Central Florida
Two-Photon Absorption In Bulk Semiconductors And Quantum Well Structures And Its Applications, Himansu Pattanaik
Electronic Theses and Dissertations
The purpose of this dissertation is to provide a study and possible applications of two-photon absorption (2PA), in direct-gap semiconductors and quantum-well (QW) semiconductor structures. One application uses extremely nondegenerate (END) 2PA, for mid-infrared (mid-IR) detection in uncooled semiconductors. The use of END, where the two photons have very different energies gives strong enhancement comapared to degenerate 2PA. This END-2PA enhanced detection is also applied to mid-IR imaging and light detection and ranging (LIDAR) in uncooled direct-gap photodiodes. A theoretical study of degenerate 2PA (D-2PA) in quantum wells, QWs, is presented, along with a new theory of ND 2PA in …
Spectral Study Of Asteroids And Laboratory Simulation Of Asteroid Organics,
2015
University of Central Florida
Spectral Study Of Asteroids And Laboratory Simulation Of Asteroid Organics, Kelsey Hargrove
Electronic Theses and Dissertations
We investigate the spectra of asteroids at near- and mid-infrared wavelengths. In 2010 and 2011 we reported the detection of 3 ?m and 3.2-3.6 ?m signatures on (24) Themis and (65) Cybele indicative of water-ice and complex organics [1] [2] [3]. We further probed other primitive asteroids in the Cybele dynamical group and Themis family, finding diversity in the shape of their 3 ?m [4] [5] [6] and 10 ?m spectral features [4]. These differences indicated mineralogical and compositional variations within these asteroid populations. Also in the mid-infrared region we studied a larger population of asteroids belonging to the Bus …
Theoretical Study Of Laser Beam Quality And Pulse Shaping By Volume Bragg Gratings,
2015
University of Central Florida
Theoretical Study Of Laser Beam Quality And Pulse Shaping By Volume Bragg Gratings, Sergiy Kaim
Electronic Theses and Dissertations
The theory of stretching and compressing of short light pulses by the chirped volume Bragg gratings (CBG) is reviewed based on spectral decomposition of short pulses and on the wavelength-dependent coupled wave equations. The analytic theory of diffraction efficiency of a CBG with constant chirp and approximate theory of time delay dispersion are presented. Based on those, we performed comparison of the approximate analytic results with the exact numeric coupled-wave modeling. We also study theoretically various definitions of laser beam width in a given cross-section. Quality of the beam is characterized by the dimensionless beam propagation products (?x???_x)?? , which …
Characterizing Exoplanet Atmospheres: From Light-Curve Observations To Radiative-Transfer Modeling,
2015
University of Central Florida
Characterizing Exoplanet Atmospheres: From Light-Curve Observations To Radiative-Transfer Modeling, Patricio Cubillos Vallejos
Electronic Theses and Dissertations
Multi-wavelength transit and secondary-eclipse light-curve observations are some of the most powerful techniques to probe the thermo-chemical properties of exoplanets. Although the large planet-to-star brightness contrast and few available spectral bands produce data with low signal-to-noise ratios, a Bayesian approach can robustly reveal what constraints we can set, without over-interpreting the data. Here I performed an end-to-end analysis of transiting exoplanet data. I analyzed space-telescope data for three planets to characterize their atmospheres and refine their orbits, investigated correlated noise estimators, and contributed to the development of the respective data-analysis pipelines. Chapters 2 and 3 describe the Photometry for Orbits, …
Microscopic Theory Of The Knight Shift,
2015
University of Central Florida
Microscopic Theory Of The Knight Shift, Bianca Hall
Electronic Theses and Dissertations
This dissertation is the beginning of the development of a microscopic theory of the Knight shift. The Knight shift experiment has been used in superconductivity research throughout history, however, a complete understanding of the Knight shift in conventional as well as unconventional superconductors does not yet exist. Motivated by the results of a literature review, which discusses Knight shift anomalies in multiple superconducting materials, this research studies a new model of the Knight shift, which involves the processes involved in nuclear magnetic resonance measurements in metals. The result of this study is a microscopic model of nuclear magnetic resonance in …
A Theoretical And Experimental Investigation Of The Physical And Chemical Properties Of Solid Nanoscale Interfaces,
2015
University of Central Florida
A Theoretical And Experimental Investigation Of The Physical And Chemical Properties Of Solid Nanoscale Interfaces, Jeronimo Matos
Electronic Theses and Dissertations
With the emerging interest in nanoscale materials, the fascinating field of surface science is rapidly growing and presenting challenges to the design of both experimental and theoretical studies. The primary aim of this dissertation is to shed some light on the physical and chemical properties of selected nanoscale materials at the interface. Furthermore, we will discuss the effective application of cutting edge theoretical and experimental techniques that are invaluable tools for understanding the systems at hand. To this effect, we use density functional theory (DFT) with the inclusion of van der Waals (vdW) interactions to study the effect of long-range …
Transverse Mode Selection And Brightness Enhancement In Laser Resonators By Means Of Volume Bragg Gratings,
2015
University of Central Florida
Transverse Mode Selection And Brightness Enhancement In Laser Resonators By Means Of Volume Bragg Gratings, Brian Anderson
Electronic Theses and Dissertations
The design of high power lasers requires large mode areas to overcome various intensity driven nonlinear effects. Increasing the aperture size within the laser can overcome these effects, but typically result in multi-transverse mode output and reduced beam quality, limiting the brightness of the system. As one possible solution, the angular selectivity of a diffractive optical element is proposed as a spatial filter, allowing for the design of compact high brightness sources not possible with conventional methods of transverse mode selection. This thesis explores the angular selectivity of volume Bragg gratings (VBGs) and their use as spatial transverse mode filters …
Resistive Pulse Study Of Vesicles And Liposomes,
2015
University of Central Florida
Resistive Pulse Study Of Vesicles And Liposomes, Yuqing Lin
Electronic Theses and Dissertations
In this work, the properties of the liposomes, the artificially created vesicles by various methods, are explored by a resistive pulse method using micropipettes. The fact that vesicles are fundamental in the wide range of functionalities they fulfill as organelles strengthen the desire of understanding the properties of them. The motivation of this work comes from the significant roles that liposomes play in the development of targeted drug delivery systems. Among other significant variables, the size of liposomes is found to be one of the dominating parameters in liposome based drug delivery, and the correlation between liposome size and delivery …
