21,977 research outputs found

    Thermal performance of a naturally ventilated building using a combined algorithm of probabilistic occupant behaviour and deterministic heat and mass balance models

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    This study explores the role of occupant behaviour in relation to natural ventilation and its effects on summer thermal performance of naturally ventillated buildings. We develop a behavioural algorithm (the Yun algorithm) representing probablistic occupant behaviour and implement this within a dynamic energy simulation tool. A core of this algorithm is the use of Markov chain and Monte Carlo methods in order to integrate probablistic window use models into dynamic energy simulation procedures. The comparison between predicted and monitored window use patterns shows good agreement. Performance of the Yn algorithm is demonstrated for active, medium and passive window users and a range of office constructions. Results indicate, for example, that in some cases, the temperature of an office occupied by the active window user in summer is up to 2.6ÂşC lower than that for the passive window user. A comparison is made with results from an alernative bahavioural algorithm developed by Humphreys [H.B. Rijal, P. Tuohy, M.A. Humphreys, J.F. Nicol, A. Samual, J. Clarke, Using results from field surveys to predict the effect of open windows on thermal comfort and energy use in buildings, Energy and Buildings 39(7)(2007) 823-836.]. In general, the two algorithms lead to similar predictions, but the results suggest that the Yun algorithm better reflects the observed time of day effects on window use (i.e. the increased probability of action on arrival)

    Synthesis and Reactivity of Tricarbonyl(1-ethoxy-carbonyl-2-methylpentadienyl)iron(1+) Cation

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    The title cation was prepared in two steps from the known (ethyl 3-methyl-6-oxo-2,4-hexadienoate)Fe(CO)3. Reation of the cation with NaBH3CN, methyl cuprate, phthalimide, water, PPh3, or malonate anions gave predominantly the products from nucleophilic attack at the C5 pentadienyl carbon

    Reply to [arXiv:1105.5147] "Are GRB 090423 and Similar Bursts due to Superconducting Cosmic Strings?"

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    The GRB outflow driven by superconducting cosmic strings is likely to be an arc rather than a usually-considered spherical cap. In such a case, the afterglows of the cosmic string GRBs could be basically consistent with the observation of the high-redshift GRBs.Comment: 2 pages, 1 figure, to appear in Phys. Rev. Let

    The F@ Framework of Designing Awareness Mechanisms in Instant Messaging

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    This paper presents our research on awareness support in Instant Messaging (IM). The paper starts with a brief overview of empirical study of IM, using an online survey and face-to-face interviews to identify user needs for awareness support. The study identified a need for supporting four aspects of awareness, awareness of multiple concurrent conversations, conversational awareness, presence awareness of a group conversation, and visibility of moment-to-moment listeners and viewers. Based on the empirical study and existing research on awareness, we have developed the F@ (read as fat) framework of awareness. F@ comprises of the abstract level and the concrete level. The former includes an in-depth description of various awareness aspects in IM, whilst the latter utilises temporal logic to formalise fundamental time-related awareness aspects. F@ helps developers gain a better understanding of awareness and thereby design usable mechanisms to support awareness. Applying F@, we have designed several mechanisms to support various aspect of awareness in IM

    Collision Integrals for the Transport Properties of Dissociating Air at High Temperatures

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    Collision integrals for the transport properties of dissociating air at high temperature
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