402 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
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Investigating the Intelligibility of a Computer Vision System for Blind Users
Computer vision systems to help blind usersare becoming increasingly common yet often these systems are not intelligible. Our work investigates the intelligibility of a wearable computer vision system to help blind users locate and identify people in their vicinity. Providing a continuous stream of information, this system allows us to explore intelligibility through interaction and instructions, going beyond studies of intelligibility that focus on explaining a decision a computer vision system might make. In a study with 13 blind users, we explored whether varying instructions (either basic or enhanced) about how the system worked would change blind usersā experience of the system. We found offering a more detailed set of instructions did not affect how successful users were using the system nor their perceived workload. We did, however, find evidence of significant differences in what they knew about the system, and they employed different, and potentially more effective, use strategies. Our findings have important implications for researchers and designers of computer vision systemsfor blind users, as well more general implications for understanding what it means to make interactive computer vision systems intelligible
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
"On our own, we can't manage": experiences with infant feeding recommendations among Malawian mothers living with HIV
<p>Abstract</p> <p>Background</p> <p>Infant feeding in communities with a high prevalence of HIV and AIDS is a potential challenge for mothers who must ultimately decide how to feed their infants within contexts that constrain their choices.</p> <p>Methods</p> <p>We investigated how infant feeding policy recommendations translate into maternal infant feeding decisions and practices using ethnographic research conducted between August 2004 and June 2005 among women participating in a prevention of mother-to-child transmission (PMTCT) program in Lilongwe, Malawi.</p> <p>Results</p> <p>Qualitative findings are that maternal ability to adhere to recommendations to breastfeed exclusively for the first six months of infant life was constrained by expectations and psycho-social support. The most salient were women's pre-existing views on breastfeeding, their understanding of the medico-scientific information, and the quality of counselling received. In contrast, maternal decisions to wean were largely influenced by household economic factors and food insecurity.</p> <p>Conclusions</p> <p>We conclude that PMTCT programs delivered in ways which "download" the responsibility of adhering to recommendations to women in the absence of adequate psycho-social and livelihood supports contribute to substantial maternal psychosocial distress in this and, likely, similar settings.</p
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