7,721 research outputs found

    Increasing security of supply by the use of a local power controller during large system disturbances

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    This paper describes intelligent ways in which distributed generation and local loads can be controlled during large system disturbances, using Local Power Controllers. When distributed generation is available, and a system disturbance is detected early enough, the generation can be dispatched, and its output power can be matched as closely as possible to local microgrid demand levels. Priority-based load shedding can be implemented to aid this process. In this state, the local microgrid supports the wider network by relieving the wider network of the micro-grid load. Should grid performance degrade further, the local microgrid can separate itself from the network and maintain power to the most important local loads, re-synchronising to the grid only after more normal performance is regained. Such an intelligent system would be a suitable for hospitals, data centres, or any other industrial facility where there are critical loads. The paper demonstrates the actions of such Local Power Controllers using laboratory experiments at the 10kVA scale

    New observations regarding deterministic, time reversible thermostats and Gauss's principle of least constraint

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    Deterministic thermostats are frequently employed in non-equilibrium molecular dynamics simulations in order to remove the heat produced irreversibly over the course of such simulations. The simplest thermostat is the Gaussian thermostat, which satisfies Gauss's principle of least constraint and fixes the peculiar kinetic energy. There are of course infinitely many ways to thermostat systems, e.g. by fixing āˆ‘iāˆ£piāˆ£Ī¼+1\sum\limits_i{|{p_i}|^{\mu + 1}}. In the present paper we provide, for the first time, convincing arguments as to why the conventional Gaussian isokinetic thermostat (Ī¼=1\mu=1) is unique in this class. We show that this thermostat minimizes the phase space compression and is the only thermostat for which the conjugate pairing rule (CPR) holds. Moreover it is shown that for finite sized systems in the absence of an applied dissipative field, all other thermostats (Ī¼=1\mu=1) perform work on the system in the same manner as a dissipative field while simultaneously removing the dissipative heat so generated. All other thermostats (Ī¼=1\mu=1) are thus auto-dissipative. Among all Ī¼\mu-thermostats, only the Ī¼=1\mu=1 Gaussian thermostat permits an equilibrium state.Comment: 27 pages including 10 figures; submitted for publication Journal of Chemical Physic

    Prosthesis coupling

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    A coupling for use in an apparatus for connecting a prosthesis to the bone of a stump of an amputated limb is described which permits a bio-compatible carbon sleeve forming a part of the prosthesis connector to float so as to prevent disturbing the skin seal around the carbon sleeve. The coupling includes a flexible member interposed between a socket that is inserted within an intermedullary cavity of the bone and the sleeve. A lock pin is carried by the prosthesis and has a stem portion which is adapted to be coaxially disposed and slideably within the tubular female socket for securing the prosthesis to the stump. The skin around the percutaneous carbon sleeve is able to move as a result of the flexing coupling so as to reduce stresses caused by changes in the stump shape and/or movement between the bone and the flesh portion of the stump

    LANDSAT/coastal processes

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    The author has identified the following significant results. Correlations between the satellite radiance values water color, Secchi disk visibility, turbidity, and attenuation coefficients were generally good. The residual was due to several factors including systematic errors in the remotely sensed data, errors, small time and space variations in the water quality measurements, and errors caused by experimental design. Satellite radiance values were closely correlated with the optical properties of the water

    Discourse and identity in a corpus of lesbian erotica

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    This article uses corpus linguistic methodologies to explore representations of lesbian desires and identities in a corpus of lesbian erotica from the 1980s and 1990s. We provide a critical examination of the ways in which ā€œlesbian gender,ā€ power, and desire are represented, (re-)produced, and enacted, often in ways that challenge hegemonic discourses of gender and sexuality. By examining word frequencies and collocations, we critically analyze some of the themes, processes, and patterns of representation in the texts. Although rooted in linguistics, we hope this article provides an accessible, interdisciplinary, and timely contribution toward developing understandings of discursive practices surrounding gender and sexuality

    Place Based Education as a Tool for Rural Career Development

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    Rural career development is rarely studied despite a large portion of American students attending school in a rural area. Rural career development is affected by factors such as student attachment to place, access to professional role models, local economic development, school funding, and geographic proximity to professional industries and higher education. A Critical Pedagogy of Place (Gruenewald, 2003) empowers students to critical explore the spacial and social constructs of their local area.Given that school counselors are in a unique position as career development and social justice advocates, this article explores the use of a Critical Pedagogy of Place as an approach to rural career development

    Z Force on the Ground: The Canadian Deployment to Iceland, 1940-41

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    The date of 10 May 1940 is well known for the start of the German blitzkrieg and the end of Neville Chamberlainā€™s tenure as British Prime Minister. That fateful day also opened a chapter in Canadaā€™s war story that, in the end, saw more than 2,600 Canadian servicemen deployed to far-away but strategic Iceland. The Canadian commitment to that remote island from June 1940 to April 1941 was a metaphoric stepping-stone in the long Allied struggle against the Axis powers in the North Atlantic, building what ultimately became a secure strategic bridge for the deployment of the forces that liberated Europe

    Rural Community Dynamics: Implications for School Counselors

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    Research shows that rural students face increasing challenges to academic, social-emotional, and career success. An understanding of student culture, background, and needs is required for a school counselor to advocate for all students. Research into the needs of rural students is lacking when compared to other populations. Research suggests that poverty, geographic isolation, cultural isolation, lack of school and community resources, and barriers to educational success as factors influencing the development and success of rural students. This article reviews the available literature and provides implications for rural school counseling practice and future research
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