Thesis (M.Ed.)--University of Delaware, 2006. / Principal faculty advisor: Eric Eslinger, School of Education. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 111-116).

Thesis (Ph. D.)--University of Washington, 1983. / Vita. Bibliography: leaves [115]-123.

M.S. / Applied Physics / The theory of stimulated Rayleigh-wing scattering in anisotropic molecular liquids is discussed. This theory is extended to include liquid mixtures. When binary mixtures are considered, a singularity is found in the threshold condition in certain circumstances. This leads to the possibility of measuring the anisotropic polarizability difference for one of the liquids. In addition, the appearance of the singularity suggests a method of determining whether saturation plays an important role in stimulated Rayleigh-wing scattering.

Nichia Corporation announced blue Light Emitting Diodes (LED) by 1993. They were widely used in markets by 1996 after combining blue LED with yellow phosphors to emit white lights. There¡¦re two keys to utilize LED as replacement light energy; one is to increase the chipset brightness, while another is to use LED arrays instead of single LED. Around 15 to 20% of LED illuminant will be transformed to visible light, while up to 85% of the LED illuminant will be transformed to heat. Therefore, before there¡¦s obvious breakthrough on LED constructions to heat, thermal management of LED is relatively important. The purpose of this research is to do value simulation by slightly change the construction of low power LED and increase its power (150, 350mA), to investigate the differences of high power LED in thermal transmission by single LED and LED arrays under different parameters, and learn if the emitted heat can be tolerated by its key materials. This research can be used as the reference to design LED products for engineers. According to the analysis result, under environment temperature of 25 to 80 Celsius Degree, the temperatures of a 0.5W LED chipset, mounted board and packing materials will increase around 3 to 4 Celsius Degrees when the environment temperature will increase one Celsius Degree. If we increase the LED chipset power to be 1W, the temperature increase for chipset and mounted board is around 3 to 4 Celsius Degrees while the temperature increase for packing materials is 3 to 9 Celsius Degrees. Regarding high power LED arrays, according to the analysis result, when the distance between two LEDs is too small, the temperature will increase dramatically; when the P value (see report content) is over 5mm, per 1mm distance increase, the chipset temperature decrease will become 1 to 2.5 Celsius Degrees from initially 3 to 5 Celsius Degrees. If we further increase the two LEDs distance, there¡¦ll be no significant effect from chipset itself but only the mounted board.

The interaction of light with small designed particles and structures gives rise to an increasing number of phenomena of potentially dramatic technological importance, such as metamaterials, superlens focusing, and enhanced spectroscopy. Metallic nanostructures with their geometry-dependent optical resonances are a topic of intense current interest due to their ability to manipulate light in ways not possible with conventional optical materials. A particularly fascinating aspect of these systems is the recently realized possibility of creating optical frequency “magnetic plasmon” responses of comparable magnitude to the “electric plasmon” response. Au nanocups at their magnetoinductive resonance have the unique ability to redirect scattered light in a direction dependent on cup orientation, as a true three-dimensional nanoantenna. As optical frequency nanoantennas, reduced-symmetry plasmonic nanoparticles have light-scattering properties that depend strongly on geometry, orientation, and variations in dielectric environment. Here we investigate how these factors influence the spectral and angular dependence of light scattered by Au nanocups. A simple dielectric substrate causes the axial, electric dipole mode of the nanocup to deviate substantially from its characteristic cos square free space scattering profile, while the transverse, magnetic dipole mode remains remarkably insensitive to the presence of the substrate. Nanoscale irregularities of the nanocup rim and the local substrate permittivity have a surprisingly large effect on the spectral- and angle-dependent light-scattering properties of these structures. The different angular scattering and wavelength response from the axial and transverse nanocup modes make the nanocup an interesting particle for the nanoscale manipulation of light in three dimensions. The sensitivity of this system to geometric and environmental factors may present opportunities for active, substrate-mediated control of light scattering.

The interaction of light with small designed particles and structures gives rise to an increasing number of phenomena of potentially dramatic technological importance, such as metamaterials, superlens focusing, and enhanced spectroscopy. Metallic nanostructures with their geometry-dependent optical resonances are a topic of intense current interest due to their ability to manipulate light in ways not possible with conventional optical materials. A particularly fascinating aspect of these systems is the recently realized possibility of creating optical frequency “magnetic plasmon” responses of comparable magnitude to the “electric plasmon” response. Au nanocups at their magnetoinductive resonance have the unique ability to redirect scattered light in a direction dependent on cup orientation, as a true three-dimensional nanoantenna. As optical frequency nanoantennas, reduced-symmetry plasmonic nanoparticles have light-scattering properties that depend strongly on geometry, orientation, and variations in dielectric environment. Here we investigate how these factors influence the spectral and angular dependence of light scattered by Au nanocups. A simple dielectric substrate causes the axial, electric dipole mode of the nanocup to deviate substantially from its characteristic cos square free space scattering profile, while the transverse, magnetic dipole mode remains remarkably insensitive to the presence of the substrate. Nanoscale irregularities of the nanocup rim and the local substrate permittivity have a surprisingly large effect on the spectral- and angle-dependent light-scattering properties of these structures. The different angular scattering and wavelength response from the axial and transverse nanocup modes make the nanocup an interesting particle for the nanoscale manipulation of light in three dimensions. The sensitivity of this system to geometric and environmental factors may present opportunities for active, substrate-mediated control of light scattering.

A structure property relationship relating photostability with the axial and peripheral substituents of Boronsubphthalocyanine (BsubPc) derivatives has been outlined: peripherally halogenating BsubPc has been determined to be the best way to increase the photostability, while axial substituents are found to have little effect. A solid state photostability test using BsubPc doped polymer films has been developed and was used to form this structure property relationship. The polymer in which BsubPc is tested is found to have an effect on the photostability and should be further explored. In addition to the structure property relationship, processes to make new BsubPc precursors, HO-BsubPc and Br-BsubPc, have been developed in order to further expand the derivatives available for study.

A structure property relationship relating photostability with the axial and peripheral substituents of Boronsubphthalocyanine (BsubPc) derivatives has been outlined: peripherally halogenating BsubPc has been determined to be the best way to increase the photostability, while axial substituents are found to have little effect. A solid state photostability test using BsubPc doped polymer films has been developed and was used to form this structure property relationship. The polymer in which BsubPc is tested is found to have an effect on the photostability and should be further explored. In addition to the structure property relationship, processes to make new BsubPc precursors, HO-BsubPc and Br-BsubPc, have been developed in order to further expand the derivatives available for study.

Blowfish is a highly segmented neutron detector array consisting of 88 cells filled with BC-505 liquid scintillator. <p>The cells make up a spherical shape that covers approximately one quarter of the total solid angle of 4 pi steradians.<p> A high-priority measurement for Blowfish is the low energy contribution to the Gerasimov-Drell-Hearn (GDH) sum rule on the deuteron, which uses circularly polarized gamma rays. <p>The experimental data that needs to be collected are the absolute cross-sections when the gamma ray helicity and target polarization are parallel and anti-parallel. To extract absolute cross-sections from the data, it will be necessary to have characterized the efficiency of the detector.<p>Another measurement that would benefit from the efficiency calibration is the photodistegration of deuterium, which has already been performed. This measurement used linearly-polarized gamma rays at energies of 2.6, 3.5, 4.0 and 6.0 MeV. The relative cross-sections from this measurement provide much useful information, but to extract the absolute cross-sections the Blowfish efficiency calibration is needed. This thesis presents this efficiency calibration. <p> The efficiency calibration was done using a 252Cf source in a parallel plate ionization chamber over the energy range of 0 to 6 MeV. <p>To determine the absolute scale of the extracted efficiency curves, an efficiency analysis and simulation of a previously characterized BC-519 liquid scintillator cell needed to be performed along with a simulation of the Blowfish detector array. <p>The measured efficiencies were consistent with those predicted by the simulation over the desired energy range.