37,241 research outputs found
Investigation of a 1/4-scale model of the Republic F-105 airplane in the Langley 19-foot pressure tunnel. Lateral control and directional stability and control characteristics of model equipped with drooped, supersonic-type, elliptical wing-root inlet
Modification of NASA Langley 8 foot high temperature tunnel to provide a unique national research facility for hypersonic air-breathing propulsion systems
A planned modification of the NASA Langley 8-Foot High Temperature Tunnel to make it a unique national research facility for hypersonic air-breathing propulsion systems is described, and some of the ongoing supporting research for that modification is discussed. The modification involves: (1) the addition of an oxygen-enrichment system which will allow the methane-air combustion-heated test stream to simulate air for propulsion testing; and (2) supplemental nozzles to expand the test simulation capability from the current nominal Mach number to 7.0 include Mach numbers 3.0, 4.5, and 5.0. Detailed design of the modifications is currently underway and the modified facility is scheduled to be available for tests of large scale propulsion systems by mid 1988
A Critical Review of the Magnetoplasmadynamic /MPD/ Thrustor for Space Applications
Magnetoplasmadynamic thrustor for space application
Investigation of the D and E regions of the ionosphere
Details of an experimental program that investigates the ionosphere using sounding rockets are presented. The investigation is part of a continuing program to gather data on the D and E regions of the ionosphere during periods of recurring natural phenomena that influence these regions. To achieve these ends, four vehicles were launched during the eclipse of the sun on March 7, 1970. Other vehicles totalling 10 in all were launched to investigate transient phenomena such as the sporadic E layer
Clinical supervision in CBT training: what do participants view as effective?
Literature pertaining to cognitive behavioural therapy (CBT) supervision is limited, particularly about CBT supervision during training. This exploratory study outlines the thoughts of supervisors and supervisees in a training context about which elements make supervision effective. Four supervisees and four experienced CBT supervisors (all from a CBT training programme and independent of one another) were interviewed and asked to consider what makes CBT supervision during training effective. Their responses were evaluated using thematic analysis (TA) and key themes identified. The fit with existing literature was considered via the use of an adapted Delphi poll. Two main themes, containing seven subthemes, were identified from the thematic analysis: ‘supervision as structured learning’ and ‘supervisory relations and process’. The adapted Delphi poll was divided into six categories denoting important characteristics of CBT supervision: (1) the supervisory relationship, (2) ethical factors, (3) generic supervisory skills, (4) mirroring the CBT approach, (5) the supervisor’s knowledge and (6) addressing difficulties. There was a good fit between the TA themes and the Delphi categories. For those engaging in CBT supervision, establishing a structure that mirrors a CBT session, alongside a supportive supervisory alliance, may promote effective CBT supervision during training
Use of implicit graph for recommending relevant videos: a simulated evaluation
In this paper, we propose a model for exploiting community based usage information for video retrieval. Implicit usage information from a pool of past users could be a valuable source to address the difficulties caused due to the semantic gap problem. We propose a graph-based implicit feedback model in which all the usage information can be represented. A number of recommendation algorithms were suggested and experimented. A simulated user evaluation is conducted on the TREC VID collection and the results are presented. Analyzing the results we found some common characteristics on the best performing algorithms, which could indicate the best way of exploiting this type of usage information
Shell tile thermal protection system
A reusable, externally applied thermal protection system for use on aerospace vehicles subject to high thermal and mechanical stresses utilizes a shell tile structure which effectively separates its primary functions as an insulator and load absorber. The tile consists of structurally strong upper and lower metallic shells manufactured from materials meeting the thermal and structural requirements incident to tile placement on the spacecraft. A lightweight, high temperature package of insulation is utilized in the upper shell while a lightweight, low temperature insulation is utilized in the lower shell. Assembly of the tile which is facilitated by a self-locking mechanism, may occur subsequent to installation of the lower shell on the spacecraft structural skin
Electron density and temperature measurements in the exhaust of a mpd source
Electron density and temperature profiles measured in exhaust of magnetoplasma-dynamic sourc
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