21,949 research outputs found

    After the SKA - Radio Astronomy in 2049

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    The concept of a Square Kilometre Array was developed to ensure that progress in Radio Astronomy in the early 21st Century continued at the same impressive pace as was achieved during the first 50 years. The SKA telescope is designed to pave that road to greater and greater sensitivity. So what technical challenges does the project face and what key innovations will drive the success of the SKA? What will the next Radio Astronomy mega-science project look like? In this article the author discusses the likely avenues of progress in the coming decades and comments on the status of radio astronomy in 2049 - the author's 70th (and presumably her retirement) year.Comment: Conference Proceedings PoS(RTS2012), 8 pages, 1 figur

    High Spatial Resolution KAO Far-Infrared Observations of the Central Regions of Infrared-Bright Galaxies

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    We present new high spatial resolution Kuiper Airborne Observatory 50 micron and/or 100 micron data for 11 infrared-bright galaxies. We also tabulate previously published KAO data for 11 other galaxies, along with the IRAS data for the bulges of M 31 and M 81. We find that L(FIR)/L(B) and L(FIR)/L(H) correlate with CO (1 - 0) intensity and tau(100). Galaxies with optical or near-infrared signatures of OB stars in their central regions have higher values of I(CO) and tau(100), as well as higher far-infrared surface brightnesses and L(FIR)/L(B) and L(FIR)/L(H) ratios. L(FIR)/L(H(alpha)) does not correlate strongly with CO and tau(100). These results support a scenario in which OB stars dominate dust heating in the more active galaxies and older stars are important in quiescent bulges.Comment: 45 pages, to appear in Ap.J. vol. 468 (Sept. 1996). 17 postscript figures and 10 postscript tables available at ftp://ipac.caltech.edu/science/bsmith/ka

    Middle and elementary school students’ changes in self-determined motivation in a basketball unit taught using the Tactical Games Model

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    Studies examining student motivation levels suggest that this is a significant factor in students’ engagement in physical education and may be positively affected when teachers employ alternative pedagogical models such as game-centered approaches (GCAs). The aim of this study was to investigate changes in self-determined motivation of students as they participated in a GCA-basketball unit taught using the Tactical Games Model (TGM). Participants were 173 students (84 girls), 79 middle school (45 girls) and 94 (39 girls) elementary school students from four seventh and five fourth/fifth grade co-educational classes. Two teachers taught 32 (middle) and 33 (elementary) level one TGM basketball lessons. Need satisfaction and self-determined motivation data were collected using a previously validated instrument, while lesson context and teacher behavior data were recorded using systematic observation instruments. Repeated measures MANOVAs were employed to examine pre-posttest differences. Results revealed a significant main effect for time in need satisfaction for both middle (relatedness increased) and elementary school students (autonomy decreased) and a significant main effect in self-determined motivation for middle school students only (introjected regulation, external regulation, and amotivation all increased). Approximately 48%/42% (middle/elementary) of lesson time was game play, 22%/22% skill practice, 17%/17% management, and 13%/19% knowledge. The primary teacher behaviors used were instruction, management, specific observation, corrective feedback and modelling. Results indicate that it is important for future research to pay greater attention to the contextual factors associated with the application of the TGM, such as the students’ previous exposure to TGM lessons, and the teachers’ training and experience in utilizing the TGM. Indeed, results of the present study demonstrate that a longer-term commitment to the TGM is necessary to reduce controlling teacher behaviors, which will lead to positive changes in students’ need satisfaction and self-determined motivation. Future research is therefore needed to embrace this challenge to provide an increased evidence-base for GCAs such as the TGM

    Getting to Know Peasants: Local Population Records and Rural Society in Nineteenth-Century France

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    Inconsistent terminology and under-reporting of agricultural occupations in the French manuscript census schedules from the nineteenth century has proved to be a serious problem for historians. Drawing on the literature that discusses these matters, this article presents evidence from a sample commune to propose a solution: creating linked population files to construct a set oflongitudinal analytical class groups into which specific occupations can be assigned in a variable way, depending on standard criteria, from one census to the next. Several tests of social data from local records using the analytical classifications are presented to demonstrate their usefulness for social history.Une terminologie flottante et le sous-dénombrement des professions agricoles dans les listes nominatives de recensement françaises du XIXe siècle ont considérablement gêné les historiens dans leur travail. S'inspirant de la documentation sur le sujet, le présent article en arrive à proposer une solution après étude d'une commune échantillon: créer des fichiers de population enchaînés pour bâtir un ensemble de catégories longitudinales et analytiques auxquelles on puisse assigner des professions particulières de façon variable, suivant des critères standards, d'un recensement à l'autre. Plusieurs tests de données sociales tirées de registres locaux faits au moyen des classifications analytiques sont présentés afin de démontrer leur utilité pour l'histoire sociale

    Electric field enhancement of efficiency in autoradiographic exposures

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    An external electric field was applied during autoradiographic exposures in an attempt to influence the path length and trajectory of image forming beta particles. Various techniques were employed to maximize the electric field applied. No evidence was found for increases in efficiency of image formation within the receiving emulsion, up to a field strength of 7 x 10 volts/cm

    Gender and school-level differences in students' moderate and vigorous physical activity levels when taught basketball through the tactical games model

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    The Tactical Games Model (TGM) prefaces the cognitive components of physical education (PE), which has implications for physical activity (PA) accumulation. PA recommendations suggest students reach 50% moderate-vigorous physical activity (MVPA). However, this criterion does not indicate the contribution from vigorous physical activity (VPA). Consequently, this study investigated: a) the effects of TGM delivery on MVPA/VPA and, b) gender/school level differences. Participants were 78 seventh and 96 fourth/fifth grade coeducational PE students from two different schools. Two teachers taught 24 (middle) and 30 (elementary) level one TGM basketball lessons. Students wore Actigraph GT3Ă— triaxial accelerometers. Data were analyzed using four one-way ANOVAs. Middle school boys had significantly higher MVPA/VPA (34.04/22.37%) than girls (25.14/15.47%). Elementary school boys had significantly higher MVPA/VPA (29.73/18.33%) than girls (23.03/14.33%). While TGM lessons provide a context where students can accumulate VPA consistent with national PA recommendations, teachers need to modify lesson activities to enable equitable PA participation

    Music Among Friends

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    Program listing performers and works performe

    Promoting equity in STEM classrooms

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    This keynote, delivered by Professor Lisa Harvey-Smith, will outline the current state of play for women and girls’ participation in STEM, and consider how staff in universities can contribute to achieving greater equity in STEM subjects. Professor Harvey-Smith is the Australian Government’s Women in STEM Ambassador and a Professor of Practice at the University of New South Wales. In her role, Lisa and her team work to cultivate the conditions in which all Australians can pursue successful and rewarding careers in STEM. The work of the Ambassador’s Office includes: providing expert advice to policy makers, peak bodies, and other stakeholders; education and outreach through the Future You national awareness raising initiative; as well as contributing to current research into equitable STEM participation and evidence-based practices to improve participation, engagement and outcomes for diverse students

    One year of monitoring the Vela pulsar using a Phased Array Feed

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    We have observed the Vela pulsar for one year using a Phased Array Feed (PAF) receiver on the 12-metre antenna of the Parkes Test-Bed Facility. These observations have allowed us to investigate the stability of the PAF beam-weights over time, to demonstrate that pulsars can be timed over long periods using PAF technology and to detect and study the most recent glitch event that occurred on 12 December 2016. The beam-weights are shown to be stable to 1% on time scales on the order of three weeks. We discuss the implications of this for monitoring pulsars using PAFs on single dish telescopes.Comment: 6 pages, 4 figures, 2 tables. Accepted for publication in PAS

    Seasoning of Aspen

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    Aspen is nor; the major forest type in the Lake States, and extensive stands are reaching maturity. Increasing quantities are being cut, and much is nor; being put to new and more exacting uses that require better air - seasoning and kiln-drying practices. The recent favorable market for green aspen lumber appears to be falling off, and the time may soon come when operators are no longer able to move green aspen. Such a change can be met by manufacturing better-quality aspen lumber and by carefully seasoning it to the desired moisture content to make it more acceptable. This report describes the principles of air seasoning and kiln drying as developed from research at the Forest Products Laboratory, with specific recommendations for the seasoning of aspen lumber, flitches, and shook stock. More detailed information may be obtained from the publications listed at the end of this report, most of which are available at the Forest Products Laboratory
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