Wright-Patterson Air Force Base

About: Wright-Patterson Air Force Base is a other organization based out in Wright-Patterson AFB, Ohio, United States. It is known for research contribution in the topics: Laser & Microstructure. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

Volume holographic image storage and electro-optical readout in a polymer-dispersed liquid-crystal film.

Abstract: We report storage and electrical switching of holographic image data in an economical polymer-dispersed liquidcrystal material. The hologram is recorded in a fast, single-step process and can be reversibly erased and restored repeatedly by the application of fields of approximately 10-15 V/ microm, with a response time of 22 micros and a relaxation time of 42 micros. Simple (quasi-sinusoidal) holographic transmission gratings also are studied with switching fields of <5 V/ microm and with response and relaxation times of 25 and 44 micros, respectively.

Phase Relations in the System Boron Oxide–Silica

Abstract: The suggested phase diagrams for the system B2O3-SiO2 as drawn from the findings of previous investigators are presented. These diagrams show the wide controversy regarding this system. The principal difficulties in obtaining reliable equilibrium data are the volatilization of B2O3, the hydration of B2O3-rich glasses, and the great viscosity of B2OrSiOz melts. In this investigation firings were made in sealed platinum capsules. Where necessary, they were opened and studied under xylene to eliminate hydration. Phases were identified by optical and X-ray methods. The liquidus was obtained by determination of the temperatures at which the stable phases of SiO2 completely dissolved in the borosilicate melts. The criteria used for equilibrium are discussed.

Cerebral Hemodynamics and Vigilance Performance

Abstract: Five studies are described using transcranial Doppler sonography (TCD) and near-infrared spectroscopy (NIRS) to examine brain systems in vigilance. The results indicate that the vigilance decrement, the temporal decline that typifies vigilance performance, is paralleled by a decline in cerebral blood flow velocity as indexed by TCD. In addition, both measures showed greater activity in the right than in the left cerebral hemisphere in response to a variety of psychophysical challenges, indicating a right hemispheric system in control of vigilance performance. The TCD measure was also found to be potentially useful in selecting observers for vigilance assignments.

Application of Large-Eddy Simulation to Supersonic Compression Ramps

Abstract: Large-eddy simulations of supersonic compression-ramp flowfields were performed by a high-order numerical method, utilizing the Smagorinsky dynamic subgrid-scale model to account for spatially underresolved stresses. Computations were carried out at a freestream Mach number of 3.0 for ramp angles of 8, 16, 20, and 24 deg. Extensive comparisons are made between the respective solutions and available experimental data that were collected at higher Reynolds numbers. These include surface pressure, skin friction, and both mean and fluctuating velocity profiles. For the 24-deg case, a number of experimentally measured statistical quantities are compared to the simulation