3,613 research outputs found

    Thermal energy storage material thermophysical property measurement and heat transfer impact

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    The thermophysical properties of salts having potential for thermal energy storage to provide peaking energy in conventional electric utility power plants were investigated. The power plants studied were the pressurized water reactor, boiling water reactor, supercritical steam reactor, and high temperature gas reactor. The salts considered were LiNO3, 63LiOH/37 LiCl eutectic, LiOH, and Na2B4O7. The thermal conductivity, specific heat (including latent heat of fusion), and density of each salt were measured for a temperature range of at least + or - 100 K of the measured melting point. Measurements were made with both reagent and commercial grades of each salt

    Anomalous hydrodynamics and "normal" fluids in rapidly rotating BECs

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    In rapidly rotating bose systems we show that there is a region of anomalous hydrodynamics whilst the system is still condensed, which coincides with the mean field quantum Hall regime. An immediate consequence is the absence of a normal fluid in any conventional sense. However, even the superfluid hydrodynamics is not described by conventional Bernoulli and continuity equations. We show there are kinematic constraints which connect spatial variations of density and phase, that the positions of vortices are not the simplest description of the dynamics of such a fluid (despite their utility in describing the instantaneous state of the condensate) and that the most compact description allows solution of some illuminating examples of motion. We demonstrate, inter alia, a very simple relation between vortices and surface waves. We show the surface waves can form a "normal fluid" which absorbs energy and angular momentum from vortex motion in the trap. The time scale of this process is sensitive to the initial configuration of the vortices, which can lead to long-lived vortex patches - perhaps related to those observed at JILA.Comment: 4 pages; 1 sentence and references modifie

    Settlement of larvae from four families of corals in response to a crustose coralline alga and its biochemical morphogens

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    Healthy benthic substrates that induce coral larvae to settle are necessary for coral recovery. Yet, the biochemical cues required to induce coral settlement have not been identified for many taxa. Here we tested the ability of the crustose coralline alga (CCA) Porolithon onkodes to induce attachment and metamorphosis, collectively termed settlement, of larvae from 15 ecologically important coral species from the families Acroporidae, Merulinidae, Poritidae, and Diploastreidae. Live CCA fragments, ethanol extracts, and hot aqueous extracts of P. onkodes induced settlement (>10%) for 11, 7, and 6 coral species, respectively. Live CCA fragments were the most effective inducer, achieving over 50% settlement for nine species. The strongest settlement responses were observed in Acropora spp.; the only non-acroporid species that settled over 50% were Diploastrea heliopora, Goniastrea retiformis, and Dipsastraea pallida. Larval settlement was reduced in treatments with chemical extracts compared with live CCA, although high settlement (>50%) was reported for six acroporid species in response to ethanol extracts of CCA. All experimental treatments failed (< 10%) to induce settlement in Montipora aequituberculata, Mycedium elephantotus, and Porites cylindrica. Individual species responded heterogeneously to all treatments, suggesting that none of the cues represent a universal settlement inducer. These results challenge the commonly-held notion that CCA ubiquitously induces coral settlement, and emphasize the critical need to assess additional cues to identify natural settlement inducers for a broad range of coral taxa

    What do you need? 2007-08 findings from a national survey of people with diagnosed HIV

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    Over the past twenty-five years, both the needs of people with diagnosed HIV and our understanding of them have changed dramatically. During this time there have been many assessments of need, usually within specific geographic boundaries (such as Primary Care Trusts) but no consistent approach to describing needs has been adopted. Most needs assessments have been shaped by a variety of local factors, including the profile of existing services. This study provides an insight into the needs of people with diagnosed HIV living in the UK, based on a final sample of 1777 people. The approach taken to measuring and describing need is the same as our previous national survey (Weatherburn et al. 2002). This approach was shaped by our earlier qualitative studies exploring the experience of people with diagnosed HIV in the early days of anti-HIV treatments (Anderson et al. 2000, Anderson & Weatherburn 1999, Anderson & Weatherburn 1998). While this study uses the same methods as our 2001-2002 survey we do not draw direct comparisons with our previous data or discuss change over time. The limitations of self-completion surveys using convenience samples make change comparisons hazardous. However, it is worth noting that in any comparison with our prior data (Weatherburn et al. 2002) current levels of need very rarely seem lower than we have previously reported. The range and extent of medical and social care, support and information needs we present here reveal significant challenges for service commissioners and providers. The first challenge is to avoid drawing quick conclusions about what the patterns of need mean for service commissioning and delivery. Needs have deliberately been separated from service use because the question of what services are ‘needed’ cannot be answered simply by identifying the extent of personal needs. The overall pattern of need is a useful starting point, but this pattern is complex

    Plus One: HIV diagnosis and disclosure

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    Plus One: HIV sero-discordant relationships among black African people in England (NAHIP) Duration: September 2010 - November 2011 Plus One involved in-depth, face-to-face interviews with black African people living in England who were in relationships where one person had diagnosed HIV and the other did not (ie. HIV serodiscordant)

    Plus One: Managing the relationship

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    Plus One: HIV sero-discordant relationships among black African people in England (NAHIP) Duration: September 2010 - November 2011 Plus One involved in-depth, face-to-face interviews with black African people living in England who were in relationships where one person had diagnosed HIV and the other did not (ie. HIV serodiscordant)

    Plus One: External Influences

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    Plus One: HIV sero-discordant relationships among black African people in England (NAHIP) Duration: September 2010 - November 2011 Plus One involved in-depth, face-to-face interviews with black African people living in England who were in relationships where one person had diagnosed HIV and the other did not (ie. HIV serodiscordant). Catherine Dodds, Peter , Annabel , Edith , John , Lawrence , Pamela , Kathie & Gary
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