643 research outputs found

    Monthly average daily global and diffuse solar radiation based on sunshine duration and clearness index for Brasov, Romania

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    The main objective of this study is to develop single location appropriate models for the estimation of the monthly average daily global and diffuse horizontal solar radiation for Brasov, Romania. The study focuses particularly on models based on the sunshine duration and clearness index. The data used for the calibration of the models were collected during a period of 4 yr, between November 2008 and October 2012, at the Transilvania University of Brasov. The testing and validation of the models was carried out using data from the online SoDa database for Brasov for the year 2005. Different statistical error tests were applied to evaluate the accuracy of the models. The predicted values are also compared with values from three other known models concerning the global and diffuse solar radiation. A new mixed model was developed for the estimation of monthly average daily global horizontal solar radiation. The data processing was performed by means of a real-time interface developed with LabVIEW graphical programming language. The parameters taken into account were the relative sunshine, the clearness index, the extraterrestrial radiation, the latitude and the longitude. The methodology is simple and effective and may be applied for any region. Its effectiveness was proven through comparison with global models

    The Stargazin-Related Protein {gamma}7 Interacts with the mRNA-Binding Protein Heterogeneous Nuclear Ribonucleoprotein A2 and Regulates the Stability of Specific mRNAs, Including CaV2.2

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    The role(s) of the novel stargazin-like {gamma}-subunit proteins remain controversial. We have shown previously that the neuron-specific {gamma}7 suppresses the expression of certain calcium channels, particularly CaV2.2, and is therefore unlikely to operate as a calcium channel subunit. We now show that the effect of {gamma}7 on CaV2.2 expression is via an increase in the degradation rate of CaV2.2 mRNA and hence a reduction of CaV2.2 protein level. Furthermore, exogenous expression of {gamma}7 in PC12 cells also decreased the endogenous CaV2.2 mRNA level. Conversely, knockdown of endogenous {gamma}7 with short-hairpin RNAs produced a reciprocal enhancement of CaV2.2 mRNA stability and an increase in endogenous calcium currents in PC12 cells. Moreover, both endogenous and expressed {gamma}7 are present on intracellular membranes, rather than the plasma membrane. The cytoplasmic C terminus of {gamma}7 is essential for all its effects, and we show that {gamma}7 binds directly via its C terminus to a heterogeneous nuclear ribonucleoprotein (hnRNP A2), which also binds to a motif in CaV2.2 mRNA, and is associated with native CaV2.2 mRNA in PC12 cells. The expression of hnRNP A2 enhances CaV2.2 IBa, and this enhancement is prevented by a concentration of {gamma}7 that alone has no effect on IBa. The effect of {gamma}7 is selective for certain mRNAs because it had no effect on {alpha}2{delta}-2 mRNA stability, but it decreased the mRNA stability for the potassium-chloride cotransporter, KCC1, which contains a similar hnRNP A2 binding motif to that in CaV2.2 mRNA. Our results indicate that {gamma}7 plays a role in stabilizing CaV2.2 mRNA

    THE EVOLUTION OF THE DESIGN AND CONSTRUCTION OF MASONRY BUILDINGS IN AUSTRALIA

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    Masonry is a construction material which is widely used in Australia in a number of forms (fired clay, concrete, calcium silicate, natural stone, autoclaved aerated concrete) and in a wide range of both loadbearing and non-loadbearing applications. As such, it serves as the primary structural element in structures such as 3-4 story “walk up” apartment buildings or low rise commercial structures, or as a veneer or infill in housing or high rise framed construction. Despite its current widespread use, for masonry to remain a viable construction material in the future, design and construction practices need to be flexible, able to adapt to change and be receptive to innovation. This applies not only to advances in materials technology and the development of new products and building systems, but also an effective response to changes in the regulatory framework which have an increasing emphasis on thermal and acoustic performance, seismic resistance and sustainable practices. In this context, an overview of the Australian past, present and possible future masonry scene is given

    THE EVOLUTION OF THE DESIGN AND CONSTRUCTION OF MASONRY BUILDINGS IN AUSTRALIA

    Get PDF
    Masonry is a construction material which is widely used in Australia in a number of forms (fired clay, concrete, calcium silicate, natural stone, autoclaved aerated concrete) and in a wide range of both loadbearing and non-loadbearing applications. As such, it serves as the primary structural element in structures such as 3-4 story “walk up” apartment buildings or low rise commercial structures, or as a veneer or infill in housing or high rise framed construction. Despite its current widespread use, for masonry to remain a viable construction material in the future, design and construction practices need to be flexible, able to adapt to change and be receptive to innovation. This applies not only to advances in materials technology and the development of new products and building systems, but also an effective response to changes in the regulatory framework which have an increasing emphasis on thermal and acoustic performance, seismic resistance and sustainable practices. In this context, an overview of the Australian past, present and possible future masonry scene is given

    Quantum corrections to critical phenomena in gravitational collapse

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    We investigate conformally coupled quantum matter fields on spherically symmetric, continuously self-similar backgrounds. By exploiting the symmetry associated with the self-similarity the general structure of the renormalized quantum stress-energy tensor can be derived. As an immediate application we consider a combination of classical, and quantum perturbations about exactly critical collapse. Generalizing the standard argument which explains the scaling law for black hole mass, MηηβM \propto |\eta-\eta^*|^\beta, we demonstrate the existence of a quantum mass gap when the classical critical exponent satisfies β0.5\beta \geq 0.5. When β<0.5\beta < 0.5 our argument is inconclusive; the semi-classical approximation breaks down in the spacetime region of interest.Comment: RevTeX, 6 pages, 3 figures included using psfi

    Should Canadian Medical Schools Implement a Widespread 3 Year Medical Curriculum?

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    Background: This paper addresses the potential costs and benefits of implementing a widespread 3 year medical curriculum across the country.Methods: We compared differences in curriculum, costs, workforce production, competency, exposure to experiences, timing of career choices, and maturity of students and physicians between 3 and 4 year programs.  We accessed this information from 5 school’s online course outlines and by performing a broad search of the literature.Results- Three and four year medical programs have very similar curricular content.  The most significant cost savings in a 3 year medical program are due to these students entering the workforce a year earlier.   A 3 year program would add more physicians to our workforce initially; however, more doctors are produced over the long term by expanding class sizes.  Test scores of graduates from 3 year programs in Canada and the US are similar to graduates from 4 year medical programs.  A shorter program could limit the exposure of students to extra curriculars and force them to make earlier career decisions; however, time spent in electives appears to be similar.Conclusions: We do not find enough compelling evidence to advocate switching all medical schools in Canada to a 3 year medical program. 

    One-loop Quantum Gravity in Schwarzschild Spacetime

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    The quantum theory of linearized perturbations of the gravitational field of a Schwarzschild black hole is presented. The fundamental operators are seen to be the perturbed Weyl scalars Ψ˙0\dot\Psi_0 and Ψ˙4\dot\Psi_4 associated with the Newman-Penrose description of the classical theory. Formulae are obtained for the expectation values of the modulus squared of these operators in the Boulware, Unruh and Hartle-Hawking quantum states. Differences between the renormalized expectation values of both Ψ˙02\bigl| \dot\Psi_0 \bigr|^2 and Ψ˙42\bigl| \dot\Psi_4 \bigr|^2 in the three quantum states are evaluated numerically.Comment: 39 pages, 11 Postscript figures, using revte

    Using the NOAA Advanced Very High Resolution Radiometer to characterise temporal and spatial trends in water temperature of large European lakes

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    Lakes are major repositories of biodiversity, provide multiple ecosystem services and are widely recognised as key indicators of environmental change. However, studies of lake response to drivers of change at a pan-European scale are exceptionally rare. The need for such studies has been given renewed impetus by concerns over environmental change and because of international policies, such as the EU Water Framework Directive (WFD), which impose legal obligations to monitor the condition of European lakes towards sustainable systems with good ecological status. This has highlighted the need for methods that can be widely applied across large spatial and temporal scales and produce comparable results. Remote sensing promises much in terms of information provision, but the spatial transferability and temporal repeatability of methods and relationships observed at individual or regional case studies remains unproven at the continental scale. This study demonstrates that NOAA Advanced Very High Resolution Radiometer (AVHRR) thermal data are capable of producing highly accurate (R2 &gt; 0.9) lake surface temperature (LST) estimates in lakes with variable hydromorphological characteristics and contrasting thermal regimes. Validation of the approach using archived AVHRR thermal data for Lake Geneva produced observations that were consistent with field data for equivalent time periods. This approach provides the basis for generalizing temporal and spatial trends in European lake surface temperature over several decades and confirms the potential of the full 30 year NOAA AVHRR archive to can provide AVHRR-derived LST estimates to help inform European policies on lake water quality.</p
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