26,391 research outputs found

    Improvement of an integral equation method in plane elasticity through modification of source density representation

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    Integral equation method with continuous functions for calculating boundary stress components in plane elasticit

    Systems and methods for determining radio frequency interference

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    The presence, frequency and amplitude of radio frequency interference superimposed on communication links originating from a terrestrial region and including a relay in a geostationary spacecraft are determined by pointing a narrow beam antenna on the satellite at the terrestrial region. The level of noise radiated from the region to the antenna is measured at a terrestrial station that is usually remote from the region. Calibrating radio signals having a plurality of predetermined EIRP's (Effective Isotropic Radiated Power) and frequencies in the spectrum are transmitted from the region through the spacecraft narrow beam antenna back to the station. At the station, the levels of the received calibrating signals are separately measured for each of the frequency bands and EIRP's

    Community development, higher education institutions and the Big Society: opportunities or opportunism?

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    In his Prison Notebooks, written between 1929-35, Gramsci claimed that 'all men are intellectuals: but not all men have in society the function of intellectuals.' He used this term 'organic intellectuals' to illustrate that those working at grassroots level who have significant knowledge(s) about the way communities of all types work, are as important to the development of society as academic intellectuals. This article explores the current idea of a 'Big Society' as a hegemonic idea. This exploration is undertaken in relation to the current economic, social and political situation and with reference to the practice of community development, lifelong learning and the role of the Higher Education Institutions (HEIs) in supporting this field of activity. In this article we use the term 'community development' as Tett defines in Morgan-Klein and Osborne (2007:104). She claims it means to 'increase the capacity of particular communities through targeted resources for particular areas'. We specifically explore the following areas: <p> ā€¢ challenging the hegemonic ideas and policies ā€¢ practising within the restrictions of cuts and limited resources ā€¢ setting up supportive networks which will sustain workers ā€¢ making meaningful international links abroad and using international examples of good practice ā€¢ turning the ideology of the Big Society into an opportunity</p> We will pose the critical questions that we think need to be addressed and which we hope will help us to find direction and an understanding of the way forward at a deeper level. We hope to create both useful and innovative knowledge which will be a valid contribution to the field of community development

    The Impact of Early Positive Results on a Mathematics and Science Partnership: The Experience of the Institute for Chemistry Literacy Through Computational Science

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    After one year of implementation, the Institute for Chemistry Literacy through Computational Science, an NSF Mathematics and Science Partnership Institute Project led by the University of Illinois at Urbana-Champaignā€™s Department of Chemistry, College of Medicine, and National Center for Supercomputing Applications, experienced statistically signiļ¬cant gains in chemistry content knowledge among students of the rural high school teachers participating in its intensive, year-round professional development course, compared to a control group. The project utilizes a two-cohort, delayed-treatment, random control trial, quasi-experimental research design with the second cohort entering treatment one year following the ļ¬rst. The three-year treatment includes intensive two-week summer institutes, occasional school year workshops and year-round, on-line collaborative lesson development, resource sharing, and expert support. The means of student pre-test scores for Cohort I (Ī·=963) and Cohort II (Ī·=862) teachers were not signiļ¬cantly different. The mean gain (difference between pre-test and post-test scores) after seven months in the classroom for Cohort I was 9.8 percentage points, compared to 6.7 percentage points for Cohort II. This statistically signiļ¬cant difference (p\u3c.001) represented an effect size of .25 standard deviation units, and indicated unusually early conļ¬rmation of treatment effects. When post-tests were compared, Cohort I students scored signiļ¬cantly higher than Cohort II and supported the gain score differences. The impact of these results on treatment and research plans is discussed. concentrating on the effect of lessening rural teachersā€™ isolation and increasing access to tools to facilitate learning

    ELSA: An Integrated, Semi-Automated Nebular Abundance Package

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    We present ELSA, a new modular software package, written in C, to analyze and manage spectroscopic data from emission-line objects. In addition to calculating plasma diagnostics and abundances from nebular emission lines, the software provides a number of convenient features including the ability to ingest logs produced by IRAF's splot task, to semi-automatically merge spectra in different wavelength ranges, and to automatically generate various data tables in machine-readable or LaTeX format. ELSA features a highly sophisticated interstellar reddening correction scheme that takes into account temperature and density effects as well as He II contamination of the hydrogen Balmer lines. Abundance calculations are performed using a 5-level atom approximation with recent atomic data, based on R. Henry's ABUN program. Improvements planned in the near future include use of a three-region ionization model, similar to IRAF's nebular package, error propagation, and the addition of ultraviolet and infrared line analysis capability. Detailed documentation for all aspects of ELSA are available at http://www.williams.edu/Astronomy/research/PN .Comment: 2 pages, contributed paper, IAU Symp. 234, Planetary Nebulae in Our Galaxy and Beyon

    Regional variation in digital cushion pressure in the forefeet of horses and elephants

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    In this study, we seek to understand how the digital cushion morphologies evident in horse and elephant feet influence internal and external foot pressures. Our novel use of invasive blood pressure monitoring equipment, combined with a pressure pad and force plate, enabled measurements of (ex vivo) digital cushion pressure under increasing axial loads in seven horse and six elephant forefeet. Linear mixed effects models (LMER) revealed that internal digital cushion pressures increase under load and differ depending on region; elephant feet experienced higher magnitudes of medial digital cushion pressure, whereas horse feet experienced higher magnitudes of centralised digital cushion pressure. Direct comparison of digital cushion pressure magnitudes in both species, at equivalent loads relative to body weight, revealed that medial and lateral pressures increased more rapidly with load in elephant limbs. Within the same approximate region, internal pressures exceeded external, palmar pressures (on the sole of the foot), supporting previous Finite Element (FE) predictions. High pressures and large variations in pressure may relate to the development of foot pathology, which is a major concern in horses and elephants in a captive/domestic environment

    The prevalence of dust on the exoplanet HD 189733b from Hubble and Spitzer observations

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    The hot Jupiter HD189733b is the most extensively observed exoplanet. Its atmosphere has been detected and characterised in transmission and eclipse spectroscopy, and its phase curve measured at several wavelengths. This paper brings together results of our campaign to obtain the complete transmission spectrum of the atmosphere of this planet from UV to IR with HST, using STIS, ACS and WFC3. We provide a new tabulation of the transmission spectrum across the entire visible and IR range. The radius ratio in each wavelength band was rederived to ensure a consistent treatment of the bulk transit parameters and stellar limb-darkening. Special care was taken to correct for, and derive realistic estimates of the uncertainties due to, both occulted and unocculted star spots. The combined spectrum is very different from the predictions of cloud-free models: it is dominated by Rayleigh scattering over the whole visible and near infrared range, the only detected features being narrow Na and K lines. We interpret this as the signature of a haze of condensate grains extending over at least 5 scale heights. We show that a dust-dominated atmosphere could also explain several puzzling features of the emission spectrum and phase curves, including the large amplitude of the phase curve at 3.6um, the small hot-spot longitude shift and the hot mid-infrared emission spectrum. We discuss possible compositions and derive some first-order estimates for the properties of the putative condensate haze/clouds. We finish by speculating that the dichotomy between the two observationally defined classes of hot Jupiter atmospheres, of which HD189733b and HD209458b are the prototypes, might not be whether they possess a temperature inversion, but whether they are clear or dusty. We also consider the possibility of a continuum of cloud properties between hot Jupiters, young Jupiters and L-type brown dwarfs.Comment: Accepted for publication in MNRAS. 31 pages, 19 figures, 8 table

    Study in optimization of microcircuit design Final report

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    Optimization of microcircuit reliabilit
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