Nonperturbative Results For Yang-Mills Theories,
2010
CP3-Origins
Nonperturbative Results For Yang-Mills Theories, Francesco Sannino, Joseph Schechter
Physics - All Scholarship
Some non perturbative aspects of the pure SU(3) Yang-Mills theory are investigated assuming a specific form of the beta function, based on a recent modification by Ryttov and Sannino of the known one for supersymmetric gauge theories. The characteristic feature is a pole at a particular value of the coupling constant, g. First it is noted, using dimensional analysis, that physical quantities behave smoothly as one travels from one side of the pole to the other. Then it is argued that the form of the integrated beta function g(m), where m is the mass scale, determines the mass gap of …
Discreteness And The Transmission Of Light From Distant Sources,
2010
Imperial College, London
Discreteness And The Transmission Of Light From Distant Sources, Fay Dowker, Joe Henson, Rafael Sorkin
Physics - All Scholarship
We model the classical transmission of a massless scalar field from a source to a detector on a background causal set. The predictions do not differ significantly from those of the continuum. Thus, introducing an intrinsic inexactitude to lengths and durations - or more specifically, replacing the Lorentzian manifold with an underlying discrete structure - need not disrupt the usual dynamics of propagation.
Plasmonic Light-Trapping And Quantum Efficiency Measurements On Nanocrystalline Silicon Solar Cells And Silicon-On-Insulator Devices,
2010
Syracuse University
Plasmonic Light-Trapping And Quantum Efficiency Measurements On Nanocrystalline Silicon Solar Cells And Silicon-On-Insulator Devices, Eric A. Schiff, Hui Zhao, Birol Ozturk, Baojie Yan, Jeff Yang
Physics - All Scholarship
Quantum efficiency measurements in nanocrystalline silicon (nc-Si:H)solar cells deposited onto textured substrates indicate that these cells are close to the "stochastic lighttrapping limit" proposed by Yablonovitch in the 1980s. An interesting alternative to texturing is "plasmonic" light-trapping based on non-textured cells and using an overlayer of metallic nanoparticles to produce light-trapping. While this type of light-trapping has not yet been demonstrated for nc-Si:H solar cells, significant photocurrent enhancements have been reported on silicon-on-insulator devices with similar optical properties to nc-Si:H. Here we report our measurements of quantum efficiencies in nc-Si:H solar cells and normalized photoconductance spectra in SOI photodetectors with …
Characterization And Correction Of Dark Current In Compact Consumer Cameras,
2010
Portland State University
Characterization And Correction Of Dark Current In Compact Consumer Cameras, Justin Charles Dunlap, Erik Bodegom, Ralf Widenhorn
Physics Faculty Publications and Presentations
A study of dark current in digital imagers within consumer grade digital cameras is presented. Dark current is shown to vary with temperature, exposure time, and ISO setting. Further, dark current is shown to increase in successive images during a series of images. Consumer cameras are often designed to be as compact as possible and therefore the digital imagers within the camera frame are prone to heat generated by nearby elements within the camera body. It is the scope of this work to characterize the dark current in such cameras and to show that the dark current, in part due …
The Case For A Directional Dark Matter Detector And The Status Of Current Experimental Efforts,
2010
Bryn Mawr College
The Case For A Directional Dark Matter Detector And The Status Of Current Experimental Efforts, S. Ahlen, N. Afshordi, James B. R. Battat, J. Billard, N. Bozorgnia, S. Burgos, T. Caldwell, J. M. Carmona, S. Cebrian, P. Colas, T. Dafni, E. Daw, D. Dujmic, A. Dushkin, W. Fedus, E. Ferrer, D. Finkbeiner, P. H. Fisher, J. Forbes, T. Fusayasu, J. Galan, T. Gamble, C. Ghag, I. Giomataris, M. Gold, H. Gomez, M. E. Gomez, P. Gondolo, A. Green, C. Grignon, O. Guillaudin, C. Hagemann, K. Hattori, S. Henderson, N. Higashi, C. Ida, F. J. Iguaz, A. Inglis, I. G. Irastorza, S. Iwaki, A. Kaboth, S. Kabuki, J. Kadyk, N. Kallivayalil, H. Kubo, S. Kurosawa, V. A. Kudryavtsev, T. Lamy, R. Lanza, T. B. Lawson, A. Lee, E. R. Lee, T. Lin, D. Loomba, J. Lopez, G. Luzon, T. Manobu, J. Martoff, F. Mayet, B. Mccluskey, E. Miller, K. Miuchi, J. Monroe, B. Morgan, D. Muna, A. St. J. Murphy, T. Naka, K. Nakamura, M. Nakamura, T. Nakano, G. G. Nicklin, H. Nishimura, K. Niwa, S. M. Paling, J. Parker, A. Petkov, M. Pipe, K. Pushkin, M. Robinson, A. Rodriguez, J. Rodriguez-Quintero, T. Sahin, R. Sanderson, N. Sanghi, D. Santos, O. Sato, T. Sawano, G. Sciolla, H. Sekiya, T. R. Slatyer, D. P. Snowden-Ifft, N. J. C. Spooner, A. Sugiyama, A. Takada, M. Takahashi, A. Takeda, T. Tanimori, K. Taniue, A. Tomas, H. Tomita, K. Tsuchiya, J. Turk, E. Tziaferi, K. Ueno, S. Vahsen, R. Vanderspek, J. Vergados, J. A. Villar, H. Wellenstein, I. Wolfe, R. K. Yamamoto, H. Yegoryan
Physics Faculty Research and Scholarship
We present the case for a dark matter detector with directional sensitivity. This document was developed at the 2009 CYGNUS workshop on directional dark matter detection, and contains contributions from theorists and experimental groups in the field. We describe the need for a dark matter detector with directional sensitivity; each directional dark matter experiment presents their project's status; and we close with a feasibility study for scaling up to a one ton directional detector, which would cost around $150M.
Field-Induced Quantum Phase Transitions In The Spin-1/2 Triangular-Lattice Antiferromagnet Cs2cubr4,
2010
Smith College
Field-Induced Quantum Phase Transitions In The Spin-1/2 Triangular-Lattice Antiferromagnet Cs2cubr4, Nathanael Alexander Fortune, Scott T. Hannahs, Y. Takano, Y. Yoshida, T. Sherline, A. A. Wilson-Muenchow, T. Ono, H. Tanaka
Physics: Faculty Publications
In classical magnetic spin systems, geometric frustration leads to a large number of states of identical energy. We report here evidence from magnetocaloric and related measurements that in Cs2CuBr4 — a geometrically frustrated Heisenberg S= 1/2 triangular antiferromagnet — quantum fluctuations stabilize a series of gapped collinear spin states bounded by first-order transitions at simple increasing fractions of the saturation magnetization for fields directed along the c axis. Only the first of these quantum phase transitions has been theoretically predicted, suggesting that quantum effects continue to dominate at fields much higher than previously considered.
Experimental Comparison Of Acr And Icamrl Magnetic Resonance Imaging Accreditation Protocols,
2010
Wright State University
Experimental Comparison Of Acr And Icamrl Magnetic Resonance Imaging Accreditation Protocols, Brock Andrew Prater
Browse all Theses and Dissertations
Two primary accrediting bodies exist for magnetic resonance imaging systems: the American College of Radiology (ACR) and the Intersocietal Commission for the Accreditation of Magnetic Resonance Laboratories (ICAMRL), each of which defines specific standards for specific image quality criteria at which MRI images must be produced. An MRI clinic that wishes to show a commitment to image quality may do so by becoming accredited by one of these organizations of their choosing. The limits of these image criteria were compared to demonstrate the standards of each accrediting body. Images were produced that fell well within the standards of both accrediting …
Development Of Optical Coherence Tomography For Tissue Diagnostics,
2010
University of Central Florida
Development Of Optical Coherence Tomography For Tissue Diagnostics, Panomsak Meemon
Electronic Theses and Dissertations
Microvasculature can be found in almost every part of the human body, including the internal organs. Importantly, abnormal changes in microvasculature are usually related to pathological development of the tissue cells. Monitoring of changes in blood flow properties in microvasculature, therefore, provides useful diagnostic information about pathological conditions in biological tissues as exemplified in glaucoma, diabetes, age related macular degeneration, port wine stains, burn-depth, and potentially skin cancer. However, the capillary network is typically only one cell in wall thickness with 5 to 10 microns in diameter and located in the dermis region of skin. Therefore, a non-invasive flow imaging …
Parameters Of Reform And Unifification In Modern Japanese,
2010
Bucknell University
Parameters Of Reform And Unifification In Modern Japanese, R. Holzlöhner, S. M. Rochester, D. Bonaccini Calia, D. Budker, James M. Higbie, W. Hackenberg
Faculty Journal Articles
No abstract provided.
Supported Mono And Bimetallic Platinum And Iron Nanoparticles Electronic, Structural, Catalytic, And Vibrational Properties,
2010
University of Central Florida
Supported Mono And Bimetallic Platinum And Iron Nanoparticles Electronic, Structural, Catalytic, And Vibrational Properties, Jason Robert Croy
Electronic Theses and Dissertations
Catalysis technologies are among the most important in the modern world. They are instrumental in the realization of a variety of products and processes including chemicals, polymers, foods, pharmaceuticals, fuels, and fuel cells. As such, interest in the catalysts that drive these processes is ongoing, and basic research has led to significant advances in the field, including the production of more environmentally friendly catalysts that can be tuned at the molecular/atomic level. However, there are many factors which influence the performance of a catalyst and many unanswered questions still remain. The first part of this work is concerned with the …
Plasmon Enhanced Near-Field Interactions In Surface Coupled Nanoparticle Arrays For Integrated Nanophotonic Devices,
2010
University of Central Florida
Plasmon Enhanced Near-Field Interactions In Surface Coupled Nanoparticle Arrays For Integrated Nanophotonic Devices, Amitabh Ghoshal
Electronic Theses and Dissertations
The current thrust towards developing silicon compatible integrated nanophotonic devices is driven by need to overcome critical challenges in electronic circuit technology related to information bandwidth and thermal management. Surface plasmon nanophotonics represents a hybrid technology at the interface of optics and electronics that could address several of the existing challenges. Surface plasmons are electronic charge density waves that can occur at a metal-dielectric interface at optical and infrared frequencies. Numerous plasmon based integrated optical devices such as waveguides, splitters, resonators and multimode interference devices have been developed, however no standard integrated device for coupling light into nanoscale optical circuits …
New Laser Technologies Analysis Of Quantum Dot And Lithographic Laser Diodes,
2010
University of Central Florida
New Laser Technologies Analysis Of Quantum Dot And Lithographic Laser Diodes, Abdullah Demir
Electronic Theses and Dissertations
The first part of this dissertation presents a comprehensive study of quantum dot (QD) lasers threshold characteristics. The threshold temperature dependence of a QD laser diode is studied in different limits of p-doping, hole level spacing and inhomogeneous broadening. Theoretical analysis shows that the threshold current of a QD laser in the limit of uniform QDs is not temperature independent and actually more temperature sensitive than the quantum well laser. The results also explain the experimental trends of negative characteristic temperature observed in QD lasers and clarify how the carrier distribution mechanisms inside and among the QDs affect the threshold …
Application Of Antenna Synthesis And Digital Signal Processing Techniques For Active Millimeter-Wave Imaging Systems,
2010
University of Central Florida
Application Of Antenna Synthesis And Digital Signal Processing Techniques For Active Millimeter-Wave Imaging Systems, Wilson Ariel Caba
Electronic Theses and Dissertations
Millimeter-wave imaging has gathered attention in recent years for its ability to penetrate clothing, thin layers of soils, and certain construction materials. However, image quality remains a challenge that needs to be addressed. One way of improving image quality is by increasing the dimensions of the collecting aperture. A sparse array can be used to synthesize a larger aperture with a limited set of relatively small detectors. In this research we design, build, and test a test-bed having an active source at 94 GHz and an array of coherent detectors, mounted on arms that extend radially on a rotary table. …
Symmetry In The Dissociative Recombination Of Polyatomic Ions And In Ultra-Cold Few Body Collisions,
2010
University of Central Florida
Symmetry In The Dissociative Recombination Of Polyatomic Ions And In Ultra-Cold Few Body Collisions, Nicolas Douguet
Electronic Theses and Dissertations
We discuss the role of symmetries in the dissociative recombinations (DR) of three polyatomic ions, namely the linear HCO+ (formyl) ion and the two highly symmetric H+3 and H3O+ (hydronium) molecular ions. Regarding the HCO+ ion, we apply a quantum mechanical treatment using the Multi-channel Quantum Defect Theory (MQDT) formalism to describe the ion-electron scattering process. Our study takes into account the Renner-Teller effect in order to model the non Born-Oppenheimer vibronic coupling in linear polyatomic ions. The coupling has shown to represent the main mechanism responsible for electronic capturing in highly excited Rydberg states associated with excited vibrational levels …
Experimental And Theoretical Study Of The Optical Properties Of Semiconductor Quantum Dots,
2010
University of Central Florida
Experimental And Theoretical Study Of The Optical Properties Of Semiconductor Quantum Dots, Gero Nootz
Electronic Theses and Dissertations
The aim of this dissertation is to gain a better understanding of the unique electronic structure of lead salt quantum dots (QDs) and its influences on the nonlinear optical (NLO) properties as well as the time dynamics of the photogenerated charge carriers. A variety of optical techniques such as Z-scan, two-photon excited fluorescence and time-resolved pump probe spectroscopy are used to measure these properties. The one-photon as well as the degenerate and nondegenerate two-photon absorption (2PA) spectra are measured and the electronic wave functions from a four-band envelope function formalism are used to model the results. We observe local maxima …
Modeling And Design Of A Photonic Crystal Chip Hosting A Quantum Network Made Of Single Spins In Quantum Dots That Interact Via Single Photons,
2010
University of Central Florida
Modeling And Design Of A Photonic Crystal Chip Hosting A Quantum Network Made Of Single Spins In Quantum Dots That Interact Via Single Photons, Hubert P. Seigneur
Electronic Theses and Dissertations
In this dissertation, the prospect of a quantum technology based on a photonic crystal chip hosting a quantum network made of quantum dot spins interacting via single photons is investigated. The mathematical procedure to deal with the Liouville-Von Neumann equation, which describes the time-evolution of the density matrix, was derived for an arbitrary system, giving general equations. Using this theoretical groundwork, a numerical model was then developed to study the spatiotemporal dynamics of entanglement between various qubits produced in a controlled way over the entire quantum network. As a result, an efficient quantum interface was engineered allowing for storage qubits …
Tracking Stellar Activity Enhancements Due To A Close-In Giant Planet In The Hd 179949 System,
2010
University of Texas at Arlington
Tracking Stellar Activity Enhancements Due To A Close-In Giant Planet In The Hd 179949 System, Levent Gurdemir
Physics Theses - Archive
We monitored CaII H and K lines (3933Å and 3968Å) of the HD 179949 system to study Planet Induced Emission (PIE) as an effect of star-planet interaction. We obtained high resolution spectra (R > 50,000) with high signal-to-noise ratio (S/N > 50 in the Ca II H and K cores) during 10 nights of observation at the McDonald Observatory. Wide band Echelle spectra covering full optical bandwidth (3,400-10,900Å) were obtained using 2.7 m Harlan J. Smith Telescope located at Mt. Locke. Detailed statistical analyses performed both for H and K cores of calcium to reveal the nature of the fluctuation in the …
The Local Structure Of Transition Metal Doped Semiconducting Boron Carbides,
2010
University of Nebraska-Lincoln
The Local Structure Of Transition Metal Doped Semiconducting Boron Carbides, Jing Liu, Guangfu Luo, Wai-Ning Mei, Orhan Kizilkaya, Eric D. Shepherd, J. I. Brand, Peter A. Dowben
Physics Faculty Publications
Transition metal doped boron carbides produced by plasma enhanced chemical vapour deposition of orthocarborane (closo-1,2-C2B10H12) and 3d metal metallocenes were investigated by performing K-edge extended x-ray absorption fine structure and x-ray absorption near edge structure measurements. The 3d transition metal atom occupies one of the icosahedral boron or carbon atomic sites within the icosahedral cage. Good agreement was obtained between experiment and models for Mn, Fe and Co doping, based on the model structures of two adjoined vertex sharing carborane cages, each containing a transition metal. The local spin configurations of all …
Role Of Quadrupole Deformation In Proton Emitting Nuclei In The Medium Mass Region,
2010
TÜBİTAK
Role Of Quadrupole Deformation In Proton Emitting Nuclei In The Medium Mass Region, Chandrasekaran Anu Radha, Velayudham Ramasubramanian, Emmanuel James Jebaseelan Samuel
Turkish Journal of Physics
Nuclear structural studies at and beyond the proton drip line is done with the help of proton radioactivity. It is found that nuclei are not necessarily always spherical. The aim of the present work is to study the role of quadrupole deformation in proton rich nuclei, particularly with respect to odd Z nuclei within the region 50 < Z < 80 near the proton drip line. The deformation is studied using triaxially deformed cranked Nilsson Strutinsky method with tuning. Some of the nuclei in the medium mass region are found to be proton emitters from the ground state with appreciable deformation. Nuclei with 62 < Z < 67 shows considerable deformation that kindled the probability of instability within the nuclei. Significant ground state deformed shapes are observed in the 67 < Z < 73 region.
Physics Of Luminescence Nanomaterials,
2010
University of Texas at Arlington
Physics Of Luminescence Nanomaterials, Boon Kuan Woo
Physics Dissertations - Archive
Luminescence oxide nanoparticles have tremendous potential in revolutionizing many interesting applications in today's emerging cutting-edge optical technology such as solid state lighting, biomedical labeling, imaging, photodynamic activation and radiation detection. In the early parts of this thesis, we synthesized two types of luminescence oxide nanoparticles, namely zinc oxide and gadolinium oxide in the hope of investigating their optical properties and to gain a deeper understanding in determining the relationship in between the ZnO's surface defect emission and its excitonic emission. We also investigated the luminescence properties of rare-earth dopants such as Ce³⁺ and Eu³⁺ doped into the host gadolinium oxide …
