733 research outputs found

    On the effect of pressure coefficient source on the energy demand of an isolated cross-ventilated building

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    Natural ventilation is a simple and effective measure to both reduce the cooling demand of buildings and improve the indoor air quality. In the prediction of heating and cooling demands by means of building energy simulations (BES), the use of pressure coefficients (Cp) from databases as input for the airflow network model is the common approach. Cp values for the same building typology may differ according to the adopted database and are generally unavailable for buildings with complex geometry. Employed Cp values may lead to differences in BES results. This manuscript presents a comparison, for different wind directions, between the Cp distributions and mean values on the facades of a detached building obtained with full-scale CFD – Reynolds-averaged Navier-Stokes (RANS) and large eddy simulation (LES) – simulations, from a database and from wind-tunnel experiments. The obtained pressure coefficients are used in the BES of a naturally ventilated building and the energy demand difference between the four approaches is quantified. Four climate zones (tropical, dry/desertic, temperate, continental) are considered. Although, in terms of accuracy of Cp prediction, LES outperforms RANS for all the wind directions considered, annual cooling energy demand is found to be relatively insensitive to the source of Cp for the current case study, while predicted peak cooling values differ up to 10.8%. On the other hand, the prediction of annual heating energy demand in cold climates varies up to 3% depending on the Cp source employed for BES simulations.</p

    The Student Journey Project: Findings so far

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    This paper reports on the ‘Student Journey Project’, a 3 year £48,000 cyclical project running from 2012-2015. The Student Journey Project is a qualitative, longitudinal project which utilises a small number of student case studies to try to understand what the ‘real’ student journey is like at MMU, covering the learning, living and social & community experiences (including what areas and topics are of particular importance to our students). It is envisaged that information from the project will be used to help highlight, prioritise and target improvement works. The project is jointly run by the Student’s Union and Business Improvement Team. Young et al (2007) argue that institutional practice in the UK has been slow to reflect the ‘Adaptation Perspective’ (Zepke and Leach, 2005) popularised in pedagogic literature, which encourages institutions to move towards adapting to the needs of students, with course content, teaching methods and assessment reflecting the diverse demands of the students. The Student Journey Project is designed with this approach in mind, with the action research methodology designed to capture and respond to the student voice. We argue that student engagement and success is crucial to discussions of quality assurance in higher education as outlined in the QAA strategy 2011-14

    Taxi

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    The semantic differential is a widely applied measurement technique in the information systems field. As we demonstrate in this study, however, there is evidence that many of the applications of the semantic differential seem to be subject to common shortcomings. In this study, we address these shortcomings by creating awareness of the requirements underlying semantic differentiation. We discuss the requirements of semantic differentiation and use them as a foundation to introduce a framework to assist researchers in applying the semantic differential more adequately. The framework puts renewed emphasis on bipolar scale selection and dimensionality testing, introduces semantic bipolarity as new criterion, and proposes distinct stages for the testing of wording and contextual contamination. We exemplify the framework using an illustration exercise, which centers on the assessment of the meaning of the concept “electronic marketplace quality”. Using a mixture of qualitative and quantitative methods, the illustration exercise clarifies the prerequisites for semantic differentiation and provides suggestions for researchers. The paper concludes with a discussion of several methodological implications

    Mental Health in the Australian Defence Force - 2010 ADF Mental Health Prevalence and Wellbeing Study: Executive Report

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    S. E. Hodson, A. C. McFarlane, M. Van Hooff and C. Davie

    Morphological variants of silent bared-teeth displays have different social interaction outcomes in crested macaques (Macaca nigra)

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    Objectives: While it has been demonstrated that even subtle variation in human facial expressions can lead to significant changes in the meaning and function of expressions, relatively few studies have examined primate facial expressions using similarly objective and rigorous analysis. Construction of primate facial expression repertoires may, therefore, be oversimplified, with expressions often arbitrarily pooled and/or split into subjective pigeonholes. Our objective is to assess whether subtle variation in primate facial expressions is linked to variation in function, and hence to inform future attempts to quantify complexity of facial communication. Materials and Methods: We used Macaque Facial Action Coding System, an anatomically based and hence more objective tool, to quantify “silent bared‐teeth” (SBT) expressions produced by wild crested macaques engaging in spontaneous behavior, and utilized discriminant analysis and bootstrapping analysis to look for morphological differences between SBT produced in four different contexts, defined by the outcome of interactions: Affiliation, Copulation, Play, and Submission. Results: We found that SBT produced in these contexts could be distinguished at significantly above‐chance rates, indicating that the expressions produced in these four contexts differ morphologically. We identified the specific facial movements that were typically used in each context, and found that the variability and intensity of facial movements also varied between contexts. Discussion: These results indicate that nonhuman primate facial expressions share the human characteristic of exhibiting meaningful subtle differences. Complexity of facial communication may not be accurately represented simply by building repertoires of distinct expressions, so further work should attempt to take this subtle variability into account

    Nematoden als indicator voor de waterkwaliteit

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    Het beoordelen van de waterkwaliteit is een lastige zaak. Vaak wordt de chemische kwaliteit bepaald, maar eigenlijk willen we weten welke effecten die heeft op de biologische kwaliteit. Veld- en microscopisch onderzoek aan biologische indicatoren is bewerkelijk en bovendien zijn de resultaten niet eenduidig. Met de ontwikkeling van DNA-analysetechnieken is het mogelijk geworden nematoden in de waterbodem snel en accuraat te analyseren. Nematoden zijn kleine aaltjes (lengte 0,3 tot 1,0 mm) die in grote aantallen en met een aanzienlijke diversiteit in de waterbodem aanwezig zijn. De combinatie van hoge dichtheden en grote verscheidenheid maakt de nematodengemeenschap tot potentiële bio-indicator voor de waterkwaliteit. Een pilot liet zien dat DNA-analyse van nematoden in de waterbodem duidelijke signalen van eutrofiëring aangaf en daarmee inzicht gaf in de waterkwaliteit

    Modeling transient particle transport in transient indoor airflow by fast fluid dynamics with the Markov chain method

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    It is crucial to accurately and efficiently predict transient particle transport in indoor environments to improve air distribution design and reduce health risks. For steady-state indoor airflow, fast fluid dynamics (FFD) + Markov chain model increased the calculation speed by around seven times compared to computational fluid dynamics (CFD) + Eulerian model and CFD + Lagrangian model, while achieving the same level of accuracy. However, the indoor airflow could be transient, if there were human behaviors involved like coughing or sneezing and air was supplied periodically. Therefore, this study developed an FFD + Markov chain model solver for predicting transient particle transport in transient indoor airflow. This investigation used two cases, transient particle transport in a ventilated two-zone chamber and a chamber with periodic air supplies, for validation. Case 1 had experimental data for validation and the results showed that the predicted particle concentration by FFD + Markov chain model matched well with the experimental data. Besides, it had similar accuracy as the CFD + Eulerian model. In the second case, the prediction by large eddy simulation (LES) was used for validating the FFD. The simulated particle concentrations by the Markov chain model and the Eulerian model were similar. The simulated particle concentrations by the Markov chain model and the Eulerian model were similar. The computational time of the FFD + Markov chain model was 7.8 times less than that of the CFD + Eulerian model
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