308 research outputs found
Apparatus for measuring electric field strength on the surface of a model vehicle Patent
Space environment simulation system for measuring spacecraft electric field strength in plasma sheat
Interaction Between Ion Beams and Plasmas
Interaction between low energy cesium ion beam and thermal cesium plasm
Interaction Between Ion Beams and Plasmas
Stability limits for ion acoustic waves due to interaction between low energy cesium ion beam and thermal cesium plasm
Surge current and electron swarm tunnel tests of thermal blanket and ground strap materials
The results are described of a series of current conduction tests with a thermal control blanket to which grounding straps have been attached. The material and the ground strap attachment procedure are described. The current conduction tests consisted of a surge current examination of the ground strap and a dilute flow, energetic electron deposition and transport through the bulk of the insulating film of this thermal blanket material. Both of these test procedures were used previously with thermal control blanket materials
Operation of solar cell arrays in dilute streaming plasmas
Operation of solar cell arrays in dilute streaming plasma
Ion beam plume and efflux characterization flight experiment study
A flight experiment and flight experiment package for a shuttle-borne flight test of an 8-cm mercury ion thruster was designed to obtain charged particle and neutral particle material transport data that cannot be obtained in conventional ground based laboratory testing facilities. By the use of both ground and space testing of ion thrusters, the flight worthiness of these ion thrusters, for other spacecraft applications, may be demonstrated. The flight experiment definition for the ion thruster initially defined a broadly ranging series of flight experiments and flight test sensors. From this larger test series and sensor list, an initial flight test configuration was selected with measurements in charged particle material transport, condensible neutral material transport, thruster internal erosion, ion beam neutralization, and ion thrust beam/space plasma electrical equilibration. These measurement areas may all be examined for a seven day shuttle sortie mission and for available test time in the 50 - 100 hour period
Investigation of ion beam diagnostics final report
Ion beam diagnostics - plasma wind tunnel stream generation and characteristics, mercury optical resonance probe, environment effects on ion stream neutralization, and electric field meter
Computing a largest empty anchored cylinder, and related problems
Let be a set of points in , and let each point of have a positive weight . We consider the problem of computing a ray emanating from the origin (resp.\ a line through the origin) such that (resp. ) is maximal. If all weights are one, this corresponds to computing a silo emanating from the origin (resp.\ a cylinder whose axis contains the origin) that does not contain any point of and whose radius is maximal. For , we show how to solve these problems in time, which is optimal in the algebraic computation tree model. For , we give algorithms that are based on the parametric search technique and run in time. The previous best known algorithms for these three-dimensional problems had almost quadratic running time. In the final part of the paper, we consider some related problem
HCI 2020: Looking Back to the Future
In March, 2007, a forum entitled HCI 2020: Human Values in a Digital Age, was held in Sanlúcar la Mayor, Spain, just outside Seville. Its purpose was to gather luminaries in computing, design, social sciences, and scientific philosophy to discuss, debate and help formulate an agenda for human-computer interaction (HCI) over the next decade and beyond. This resulted in a detailed report, released in April 2008, in the form of a book called Being Human: Human-Computer Interaction in the Year 20201, authored by 45 members of the wider HCI community. In this panel, we shall build from four core questions. How successfully did the HCI 2020 forum and report recognize trends and shape HCI? What major trends or issues did they fail to anticipate? How valuable to the HCI community, to the participants, and to the sponsoring organizations was the forum and the report? And finally, what does this history suggest about both the process and the ultimate value to HCI, to computing in general, and to the world, of creating a HCI 2035 vison?
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