ASCA


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ASCA

Fourth in the series of small (500 kg) Japanese space science satellites devoted to X-ray astronomy. It was launched into a 560-km, 31° inclination orbit in Feb. 1993, carrying a payload of four identical grazing incidence X-ray telescopes (conical foil). Two telescopes had gas scintillation proportional counters in the focal plane and two had X-ray-sensitive CCDs (provided by NASA). The mission's main strength was X-ray spectroscopy. Both types of detector gave much improved energy resolutions over ASCA's working range of 0.5–10 keV, compared with the widely used imaging proportional counter. Apart from a gradual deterioration in the energy resolution of the CCDs caused by in-orbit radiation damage, all instruments aboard ASCA continued to function up to the middle of 2000, by which time nearly 4000 separate observations had been carried out. Among many scientific advances were the detection of a population of partly obscured active galactic nuclei (see active galaxy), whose hard X-ray spectra suggested that they formed a major component of the X-ray background radiation; the first evidence for strong gravity in the form of a broad iron fluorescence line; and the measurement of metal-rich spectra in the ejecta of several supernova remnants. The mission ended in July 2000 when a geomagnetic storm caused by an unusually large solar flare irrevocably altered the orbital attitude of the satellite and the orientation of its solar panels, taking the panels away from the Sun and effectively destroying ASCA's power supply. ASCA re-entered the Earth's atmosphere in 2001. See also Astro-E2; Ginga.
References in periodicals archive ?
ASCA -Jordan continuously seeks to develop both accounting and management sciences as well as all related principles applicable to all or some professional services.
Our study sheds light on the mechanisms leading to ASCA generation, Leonardi said.
How ASCA enables different nations to conduct fire support missions.
With regard to the ASCA National Model (ASCA, 2012), 207 (52%) participants reported that implementation was started at their school and 103 (26%) reported that implementation was complete at their school.
ASCA (2004) career development competencies focus on awareness, readiness, the acquisition of information, goals, and the development of the knowledge and skills to achieve said goals.
Most recently, ASCA has begun a collaborative relationship with a program in Dumaguete that works with homeless and at risk youth including providing a shelter - gampanan- for young girls who have been rescued from human trafficking.
The ASCA National Model can serve as a contextual framework around which basic supervision skills and knowledge can be used.
Across these varied roles and responsibilities, school counselors are expected to always act in an ethical manner (ACA, 2005; ASCA, 2010); however, the school context presents distinctive complexities that, if not acknowledged and skillfully responded to, may interfere with ethical practice.
ASCA took part in organising this course in response to the request of the Economic Development Department in Abu Dhabi and the International Accounting Standards Board (IASB) following the success and the significant results achieved in the course held in cooperation with the Society last year.
Following the development of the National Standards, ASCA (2003, 2005) supported the creation of the ASCA National Model, which emphasizes the importance of a comprehensive school counseling program that has a mission, vision, and proactive belief system designed to ensure that every student benefits from the school counseling program.
Through the work of ASCA, the American Correctional Association and other correctional health-related organizations, it is possible to develop a national prisoner health surveillance system to provide important data for health disaster planning and management.
Additionally, he was president of APGA during my presidential tenure with ASCA.