24,674 research outputs found

    Assessing electron heat flux dropouts as signatures of magnetic field line disconnection from the Sun

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    Suprathermal electrons focused along magnetic field lines, called the strahl, carry heat flux away from the Sun. Various factors can cause heat flux dropouts (HFDs), including times when the strahl almost vanishes. HFDs are a necessary but insufficient condition for detecting magnetic flux disconnected from the Sun. To quantitatively assess the fraction of HFDs which might be due to disconnected fields, we use four years of suprathermal electron data from the Wind spacecraft to perform a comprehensive survey of heat flux dropouts with durations greater than an hour. Eliminating periods within interplanetary coronal mass ejections or containing counterstreaming electrons, we find that only ∼10% of HFDs have signatures consistent with disconnected flux

    Device for measuring the temperature of liquid and gaseous hydrogen Final report

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    Fabrication and test data cryogenic temperature transducer extremely fast in response to temperature changes - device for measuring temperature of liquid and gaseous hydroge

    How can the concepts of habitus and field help us to understand the engagement of educational workers in higher Education?

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    In ‘Making a European area of lifelong learning a reality’, the EU stressed the role of universities in relation to lifelong learning, a role that entails a need for widening access to universities, particularly for those not coming through the traditional direct route of upper secondary education. As teachers play a significant role in the quality of the lifelong learning as well as in motivating future generations to take part in lifelong learning, education and training for teachers becomes important; not only in relation to initial teacher education, but also in relation to a continuous development of knowledge and skills. This paper represents the first stage of a larger comparative project intended to examine and compare educational workers’ (i.e. professionals involved in teaching in the class room) participation in higher education in England and Denmark, their access and interest. In particular, the paper relates participation and engagement to national and international educational policies and frames this work within an examination of the social background of the professional groups. The key research questions at this stage of the work are methodological and can be summed up by the overarching question, “How can the concepts of habitus and field help us to understand levels of engagement of educational workers in Higher Education”? The paper reports the results of our review of current policies and our efforts to identify the structural relations within the educational professional fields in each country. To do so we are developing a theoretical model using the relational analytical approach advocated by Bourdieu. As such, our work is an early stage attempt at operationalising Bourdieu’s observations regarding the dynamics of field. This seems to us to provide an important conceptual approach to understanding the habitus of educational workers in the context of the dynamics of a fast changing policy arena and the complexities of the backgrounds of individuals working in the educational field. The model attempts to build in the reflexivity that Bourdieu demands for a ‘science’ that is not weakened by over-emphasis on either the objective structural relations or the subjective phenomenology of experience. Thus, the paper presents a preliminary contextual analysis of the factors that enable an understanding of engagement or lack of engagement in higher level learning among school-based education workers in the two EU countries and is related to a larger research project that explores habitus (both individual and collective) among these groups of education workers

    Mean velocity, turbulence intensity and turbulence convection velocity measurements for a convergent nozzle in a free jet wind tunnel

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    The effect of light on the mean flow and turbulence properties of a 0.056 m circular jet were determined in a free jet wind tunnel. The nozzle exit velocity was 122 m/sec, and the wind tunnel velocity was set at 0, 12, 37, and 61 m/sec. Measurements of flow properties including mean velocity, turbulence intensity and spectra, and eddy convection velocity were carried out using two linearized hot wire anemometers. Normalization factors were determined for the mean velocity and turbulence convection velocity

    CO2 laser waveguiding in proton implanted GaAs

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    Surface layers capable of supporting optical modes at 10.6 microns have been produced in n-type GaAs wafers through 300 keV proton implantation. The dominant mechanism for this effect appears to be free carrier compensation. Characterization of the implanted layers by analysis of infrared reflectivity spectra and synchronous coupling at 10.6 microns produced results in good agreement with elementary models. These results of sample characterization by infrared reflectivity and by CO2 laser waveguiding as implanted are presented and evaluated

    PRODUCTION RISK REVISITED IN A STOCHASTIC FRONTIER FRAMEWORK: EVALUATING NOISE AND INEFFICIENCY IN COVER CROP SYSTEMS

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    This paper investigates both risk and technical inefficiency in a general stochastic frontier framework that is consistent with the Just-Pope framework. After applying the model to two separate cash crop-cover crop systems, the more general stochastic frontier model is found to reorder the noisiness of alternative cover crop regimes.Crop Production/Industries, Risk and Uncertainty,
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