6,302 research outputs found
Vibration isolation and pressure compensation apparatus for sensitive instrumentation
A system for attenuating the inherent vibration associated with a mechanical refrigeration unit employed to cryogenically cool sensitive instruments used in measuring chemical constituents of the atmosphere is described. A modular system including an instrument housing and a reaction bracket with a refrigerator unit floated there between comprise the instrumentation system. A pair of evacuated bellows that "float' refrigerator unit and provide pressure compensation at all levels of pressure from seal level to the vacuum of space. Vibration isolators and when needed provide additional vibration damping for the refrigerator unit. A flexible thermal strap (20 K) serves to provide essentially vibration free thermal contact between cold tip of the refrigerator unit and the instrument component mounted on the IDL mount. Another flexible strap (77 K) serves to provide vibration free thermal contact between the TDL mount thermal shroud and a thermal shroud disposed about the thermal shaft
Thomas and Sosin\u27s Therapeutic Expedition: Equipping the Christian Counselor for the Journey (Book Review)
Research for counselling practice
In many professional fields, including counselling and education, there have been significant efforts to bring practice and research closer together. However, for each situation and each new practice problem and responsive research question, there is bridging to be done. This paper takes the form of an autoethnographic essay: it tells a story of the first author’s engagement in a small research project that offered opportunities to negotiate her way toward collaboration and respect as a researcher in her own community. As a school counsellor, she held concerns for the positioning of a small group of Pasifika students in the school. This research aimed to consider how the school might do better in serving the educational interests of these students and their families. The article focuses on the shaping effects of the research for the first author’s professional and personal life. Its argument is that her experiences as researcher have profoundly shaped the counsellor it is possible for her to be
Crisp, Porter, and Elshof\u27s Christian Scholarship in the Twenty-First Century: Prospects and Perils (Book Review)
Fritz\u27s Freedom: Battle strategies for conquering temptation (Book Review)
A review of Fritz, E. (2015). Freedom: Battle strategies for conquering temptation. San Francisco, CA: Ignatious Press. 203 pp. $ 14.95. ISBN 978162164069
Kostenberger and Croteau\u27s Which Bible Translation Should I Use?: A Comparison of 4 Major Recent Versions (Book Review)
Thermoelectric temperature control system for the pushbroom microwave radiometer (PBMR)
A closed loop thermoelectric temperature control system is developed for stabilizing sensitive RF integrated circuits within a microwave radiometer to an accuracy of + or - 0.1 C over a range of ambient conditions from -20 C to +45 C. The dual mode (heating and cooling) control concept utilizes partial thermal isolation of the RF units from an instrument deck which is thermally controlled by thermoelectric coolers and thin film heaters. The temperature control concept is simulated with a thermal analyzer program (MITAS) which consists of 37 nodes and 61 conductors. A full scale thermal mockup is tested in the laboratory at temperatures of 0 C, 21 C, and 45 C to confirm the validity of the control concept. A flight radiometer and temperature control system is successfully flight tested on the NASA Skyvan aircraft
Conceptual design and structural analysis of the spectroscopy of the atmosphere using far infrared emission (SAFIRE) instrument
The conceptual design and structural analysis for the Spectroscopy of the Atmosphere using Far Infrared Emission (SAFIRE) Instrument are provided. SAFIRE, which is an international effort, is proposed for the Earth Observing Systems (EOS) program for atmospheric ozone studies. A concept was developed which meets mission requirements and is the product of numerous parametric studies and design/analysis iterations. Stiffness, thermal stability, and weight constraints led to a graphite/epoxy composite design for the optical bench and supporting struts. The structural configuration was determined by considering various mounting arrangements of the optical, cryo, and electronic components. Quasi-static, thermal, modal, and dynamic response analyses were performed, and the results are presented for the selected configuration
Impact of the Redheaded Pine Sawfly (Hymenoptera: Diprionidae) on Young Red Pine Plantations
The ecology of the redheaded pine sawfly was studied relative to its impact on red pine plantations. An ecological model, which formed the basis for socioeconomic analysis, was constructed. Because the sawfly prefers trees under moisture stress, damage is most severe in stands growing on sand blows, where there is competition for moisture from bracken fern and hardwoods, and where soils are too moist, too shallow, or too compacted. Outbreaks also appear to be related to dry years. The sawfly has a variable impact on multiple-use values. Because it injures the least productive trees in a stand, timber is only indirectly affected. Small openings created by tree mortality after an outbreak may provide edge \u27Wildlife habitat. The sawfly has both negative and positive effects on recreationists, depending upon the type of recreation; it may be a nuisance to campers, but may positively influence hunting. Preventive sawfly management involves proper site selection for red pine
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