1,052 research outputs found
Satellite Capabilities Mapping - Utilizing Small Satellites
The cost and schedule advantages small satellites have over larger legacy systems have been studied, but there has been very little experimentation performed to determine whether small satellites can actually deliver the capabilities of larger spacecraft. To date, a desired operational capability has not been fully realized by a scalable satellite design. Advances in sensor technology have led to significant reductions in size, weight, and power (SWaP) presenting an opportunity to exploit the evolution of space operations by using small satellites to perform specific missions. This paper describes a methodology that maps a specific set of large space vehicle capabilities to CubeSats. The process examines the utility of advanced sensors. Space weather has been identified as an excellent mission area to exploit the potential of small satellites. Advances in micro-electronics have produced sensors with reduced SWaP, making them viable test subjects. Mapping capabilities to a single or constellation of small satellites, could provide solutions and affordable options to the adverse challenges facing space operations. The methodology developed here selects sensor of the National Polar-Orbiting Environmental Satellite System (NPOESS) Space Environmental Sensor Suite (SESS) and maps them to a CubeSat illustrating a small satellite can perform an operational mission
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Development Of Third Harmonic Generation As A Short Pulse Probe Of Shock Heated Material
We are studying high-pressure laser produced shock waves in silicon (100). To examine the material dynamics, we are performing pump-probe style experiments utilizing 600 ps and 40 fs laser pulses from a Ti:sapphire laser. Two-dimensional interferometry reveals information about the shock breakout, while third harmonic light generated at the rear surface is used to infer the crystalline state of the material as a function of time. Sustained third harmonic generation (THG) during a similar to 100 kbar shock breakout indicate that the rear surface remains crystalline for at least 3 ns. However, a decrease in THG during a similar to 300 kbar shock breakout suggests a different behavior, which could include a change in crystalline structure.Mechanical Engineerin
Studies on the Role of Solar Ultraviolet Radiation in Natural Water Purification by Aquatic Ecosystems
The possibility that pollution might deplete the stratospheric ozone layer and intensify solar UV at the earth\u27s surface focuses attention on the role of solar UV in the various ecosystems at the earth\u27s surface. Previous studies suggested that solar UV might contribute to bacterial die off in wastewater and the studies reported here were directed toward elucidating the action of solar UV in natural waters.
It has been assumed that solar UV action on aquatic ecosystems can be evaluated (using proper models) on the basis of the following four independently measurable quantities: I) the intensity of solar UV at the water surface, 2) the attenuation of the UV in the water column, 3) the position of the critical organisms in the water, and 4) the sensitivity of the individual organisms to solar UV exposure. These four factors have been investigated on a continuing basis and the results of measurements have been utilized along with special field and laboratory experiments to assess UV-B actions.
Field work has focused on the succession of organisms, their locations in the water column, a,d under more controlled conditions, the killing of E. coli by natural sunlight. Laboratory work has included studies of UV-B lethality, its ability to stimulate positioning responses, and its depression of the photosynthetic activity of algae. Laboratory and field observations have been interpreted through models and our results are consistent with the hypothesis that solar UV is a significant agent for the aquatic microorganisms we have tested
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Secondary Natural Gas Recovery: Targeted Technology Applications for Infield Reserve Growth in Deltaifc Sand-Rich Low to Conventional Permeability Reservoirs in the Wilcox Group, Lake Creek Field, Texas
The potential for secondary incremental recovery of natural gas exists in complex fluvial-deltaic reservoirs of the Texas Gulf Coast. Four deltaic parasequences were identified using well logs calibrated to cores in the G sandstone. Engineering evaluations of production performance and pressures are compared with reservoir facies; these evaluations demonstrate the importance of identifying reservoir facies in maximizing recovery of natural gas. A well-log-based model to predict the free-water level and effective gas permeabilities was tested and calibrated using Wilcox gas reservoirs. Key reservoir parameters of porosity, water saturation, permeability, and capillary pressure are related in a single equation. Analysis of natural gas reservoirs from the Wilcox Deltaic sandstones in the Houston Embayment (WX-1) in East Texas indicates that reserve growth potential of approximately 60 percent over the current estimate of ultimate recovery is possible in deltaic sandstone reservoirs in the Lake Creek Unit. Detailed geologic, engineering, and petrophysical evaluation of the G sandstone reservoir in the Lake Creek Unit indicates that the maximum additional incremental gas opportunities exist in the flank region adjacent to the area currently developed in the Lake Creek field. The location, number, and economic feasibility of additional wells required to convert this resource to producible reserves were not evaluated.Bureau of Economic Geolog
Intensity modulated radiation therapy for squamous cell carcinoma of the vulva: Treatment technique and outcomes
Sustaining and Realizing the Promise of Telemedicine
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140277/1/tmj.2012.0282.pd
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