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The investigation of two poorly understood but technologically important physical properties of silicate glasses and related materials is described. The use of Electron Paramagnetic Resonance to investigate the nature of radiation-induced damage in glasses exposed to a variety of high-energy radiation sources is discussed first. Second, the measurement of the nonlinear index of refraction coefficient in a variety of optical materials related to the design of high-power laser systems is described. The radiation damage investigations rely heavily on the comparison of experimental results for different experimental situations. The comparison of EPR lineshapes, absolute spin densities and power saturation behavior is used to probe a variety of microscopic and macroscopic aspects of radiation damage in glasses. Comparison of radiation damage associated with exposure to gamma rays and fast neutrons (and combinations thereof) are interpreted in terms of the microscopic damage mechanisms which are expected to be associated with the specific radiations. Comparison of radiation damage behavior in different types of glasses is also interpreted in terms of the behavior expected for the specific materials. The body of data which is generated is found to be internally self-consistent and is also generally consistent with the radiation damage behavior expected for specific situations. …

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This thesis describes the design, selection and scale model test results of a contour design for a convectively-cooled, ground test nozzle extension which originates at an area ratio of 5:1 (termination point of main nozzle).

The inelastic interactions of negative pi mesons with protons at 374, 417, and 454 Mev incident pi kinetic energy are studied by measuring the differential distributions of finalstate neutrons. The pi source is an internal target of the Berkeley 184-inch synchrocyclotron. A magnetic beamtransport system momentum-anaiyzes and focuses the pi beam at a liquid hydrogen target located in an adjacent shielded experimental area. The time-of- flight distribution of neutral particles is measured at various laboratorysystem angles between 10 and 65 deg. Neutral particles are detected by observing the charged products of their interactions in plastic scintillator. The time-of- flight information is determined electronically by time-to-height conversion and pulse-height analysis. The time resolution of the total system is 1.0 nsec. Detected neutral particles accompanied by charged particles are separated by the electronic system from those not accompanied by charged particles. Analysis presuming the principal inelastic reactions to be pi /sup -/p yields pi /sup +/ pi /sup -/n and pi /sup -/p yields pi /sup 0/ pi /sup 0/n separates the time-of-flight spectra into gamma rays, neutrons from the reaction pi /sup -/p yields pi /sup 0/n, and inelastic neutrons. Calculated values of the neutron- detection efficiency are used in the …

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GPUs have emerged as a powerful tool for accelerating general-purpose applications. The availability of programming languages that makes writing general-purpose applications for running on GPUs tractable have consolidated GPUs as an alternative for accelerating generalpurpose applications. Among the areas that have bene#12;ted from GPU acceleration are: signal and image processing, computational uid dynamics, quantum chemistry, and, in general, the High Performance Computing (HPC) Industry. In order to continue to exploit higher levels of parallelism with GPUs, multi-GPU systems are gaining popularity. In this context, single-GPU applications are parallelized for running in multi-GPU systems. Furthermore, multi-GPU systems help to solve the GPU memory limitation for applications with large application memory footprint. Parallelizing single-GPU applications has been approached by libraries that distribute the workload at runtime, however, they impose execution overhead and are not portable. On the other hand, on traditional CPU systems, parallelization has been approached through application transformation at pre-compile time, which enhances the application to distribute the workload at application level and does not have the issues of library-based approaches. Hence, a parallelization scheme for GPU systems based on application transformation is needed. Like any computing engine of today, reliability is also a concern in GPUs. GPUs are vulnerable …