9,728 research outputs found

    The use of the principle of superposition in measuring and predicting the thermal characteristics of an electronic equipment operated in a space environment

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    The advantages and possible pitfalls of using a generalized method of measuring and, based on these measurements, predicting the transient or steady-state thermal response characteristics of an electronic equipment designed to operate in a space environment are reviewed. The method requires generation of a set of thermal influence coefficients by test measurement in vacuo. A implified thermal mockup isused in this test. Once this data set is measured, temperatures resulting from arbitrary steady-state or time varying power profiles can be economically calculated with the aid of a digital computer

    Holomorphic geometric models for representations of C∗C^*-algebras

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    Representations of C∗C^*-algebras are realized on section spaces of holomorphic homogeneous vector bundles. The corresponding section spaces are investigated by means of a new notion of reproducing kernel, suitable for dealing with involutive diffeomorphisms defined on the base spaces of the bundles. Applications of this technique to dilation theory of completely positive maps are explored and the critical role of complexified homogeneous spaces in connection with the Stinespring dilations is pointed out. The general results are further illustrated by a discussion of several specific topics, including similarity orbits of representations of amenable Banach algebras, similarity orbits of conditional expectations, geometric models of representations of Cuntz algebras, the relationship to endomorphisms of B(H){\mathcal B}({\mathcal H}), and non-commutative stochastic analysis.Comment: 45 page

    Molecular dynamics simulations of the interactions of potential foulant molecules and a reverse osmosis membrane

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    Reverse osmosis (RO) is increasingly one of the most common technologies for desalination worldwide. However, fouling of the membranes used in the RO process remains one of the main challenges. In order to better understand the molecular basis of fouling the interactions of a fully atomistic model of a polyamide membrane with three different foulant molecules, oxygen gas, glucose and phenol, are investigated using molecular dynamics simulations. In addition to unbiased simulations, umbrella sampling methods have been used to calculate the free energy profiles of the membrane-foulant interactions. The results show that each of the three foulants interacts with the membrane in a different manner.It is found that a build up of the two organic foulants, glucose and phenol, occurs at the membrane-saline solution, due to the favourable nature of the interaction in this region, and that the presence of these foulants reduces the rate of flow of water molecules over the membrane-solution interface. However, analysis of the hydrogen bonding shows that the origin of attraction of the foulant for the membrane differs. In the case of oxygen gas the simulations show that a build up of gas within the membrane is likely, although, no deterioration in the membrane performance was observed

    Profiling Consumer Trend-setters in the Canadian Healthy-foods Market

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    The agri-food industry faces new challenges as consumer demand for new, healthier foods increases. Media headlines frequently mention health benefits from certain foods and food components, and consumers are more health conscious because they are aging. They realize their food choices can reduce their risk of developing chronic illnesses such as cancer and heart disease. The competitive advantages for firms who are the first to bring their food innovations to market will depend in part on the efficacy of their marketing strategies. Firms that can identify and target those consumers who are most interested in trying new foods with enhanced functional health properties will likely be the most successful. This paper identifies attitudinal and sociodemographic characteristics that influence a consumer’s desire to be among the first to try innovative functional foods.Consumer/Household Economics, Health Economics and Policy, Marketing,

    The polar temperature of Venus

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    Interferometric and polarization measurements of polar regions of Venu

    On the choice of colliding beams to study deformation effects in relativistic heavy ion collisions

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    It has been suggested that collisions between deformed shapes will lead to interesting effects on various observables such as K production and elliptic flow. Simple formulae can be written down which show how to choose the colliding beams which will maximise the effects of deformation.Comment: 2 pages, this version supersedes the previous on

    The influence of process gas type on the enamel surface condition of a high power diode laser generated single-stage ceramic tile grout seal

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    Almost all laser materials processing operations require the simultaneous use of an process or assist gas. This paper examines the use of O2, Ar, N2 and He as process gasses during the firing of a vitreous enamel to form a single-stage ceramic tile grout seal with a high power diode laser (HPDL) and the effects thereof on the surface condition of the glaze. The findings revealed marked differences in the surface condition of the HPDL generated enamel glaze depending upon the process gas used. The use of O2 as the process gas was seen to result in glazes with far fewer microcracks and porosities than those generated with any of the other three gasses, particularly He. Such differences were found to be due to the ability of the smaller O2 gas molecules to dissolve molecularly into the open structure of the HPDL generated enamel glaze and also, the inherent reactiveness of O2 which consequently effects exothermic reactions when it is used as a process gas. Both occurrences were seen, in turn, to affect the cooling rate and therefore the tendency of the molten glaze to generate microcracks when cooled
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