1,720,989 research outputs found

    Thermal dynamic transfer properties of the opaque envelope: Analytical and numerical tools for the assessment of the response to summer outdoor conditions

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    The reliable estimation of buildings energy needs for cooling is a crucial issue in the implementation of the EPB Directive 2010/31/EU (formerly 2002/91/EC), especially in central and southern Europe climates. On this purpose one of the main topics is to predict the behavior of the opaque envelope subjected to variable boundary conditions. The EN ISO 13786:2007 technical standard assumes sinusoidal boundary conditions and introduces dynamic thermal characteristics. The aim of this paper is to assess the deviation arising by the use of different approaches for the calculation of the dynamic thermal characteristics of an opaque envelope element under periodic non sinusoidal boundary conditions. The EN ISO 13786 procedure has been firstly applied by decomposing the external forcing temperature by means of the Fast Fourier Transform (FFT) analysis. A comparison with different approaches, such as Finite Difference Methods (FDM) and Transfer Function Methods (TFM), has been carried out. The predictions of the EN ISO 13786 with a sinusoidal forcing temperature (i.e., standard approach) have also been assessed, comparing the results to the ones obtained through the FFT analysis. Furthermore, corrections to the periodic thermal transmittance and to the time shift have been proposed, in order to improve the explicative worth of those parameters

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Analysis of the influence of installation thermal bridges on windows performance: The case of clay block walls

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    The building’s energy performance is the result not only of material and component performances, but also of the way the components are interconnected. Concerning windows, their energy performance, which is usually evaluated by using the glass and frame heat transfer coefficients and the linear heat transfer coefficients of the glazing spacer, depends also on the frame installation. In this paper the entity of thermal losses due to the frame installation has been evaluated in terms of linear thermal transmittance calculated in accordance with the standard EN ISO 10211:2007 using THERM 5.2. The analysis of thermal bridges between a wooden frame window installed into two different kinds of external clay block walls has been carried out. The linear thermal transmittances have been calculated for three cases regarding the position (external, internal, and intermediate) and three concerning the insulation of the hole perimeter (non insulated, insulated and with insulation over fixed frame). The impact of the window installation on thermal losses has been estimated and its dependence on different sizes has been evaluated. A new graphical representation has been suggested. The frame position and the configuration of the window hole insulation result to have a relevant impact on the overall thermal performance of the considered window

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Insufficienza Celiaco Mesenterica

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    L’insufficienza celiaco-mesenterica (ICM) è una sindrome clinica in cui il sintomo cardine è rappresentato dal dolore addominale che insorge nella fase post-prandiale, e che è provocata dall’inadeguata vascolarizzazione di uno o più settori dell’apparato digerente. Essa insorge per la presenza di lesioni ostruttive a carico delle tre principali arterie splancniche: il tripode celiaco (TC), l’arteria mesenterica superiore (AMS) e quella inferiore (AMI). Esistono due forme di ICM, una acuta e una cronica, che differiscono dal punto di vista fisiopatologico, oltre che per eziologia e clinica, sottolineando peraltro la possibile evoluzione improvvisa da cronica in acuta, fino all’evoluzione in infarto intestinale più o meno esteso. Circa il 17,5% degli ultrasessantacinquenni presenta una patologia ostruttiva con interessamento significativo di almeno una delle tre arterie splancniche.1 Inoltre, studi autoptici hanno dimostrato che la prevalenza della malattia aterosclerotica a carico delle arterie mesenteriche si attesta attorno al 6-10%, con l’occlusione completa di almeno uno dei tre vasi nel 3% dei soggetti.2 Grazie alla notevole collateralità fisiologicamente presente sia all’interno del circolo splancnico, che tra questo e i distretti adiacenti, la maggior parte dei soggetti affetti da malattia occlusiva mesenterica rimane asintomatica, così che l’incidenza precisa della ICM cronica rimane sconosciuta: negli USA, essa è responsabile di poco meno di 1 ricovero ogni 100,000,3 mentre la forma acuta risulta relativamente più frequente, quasi 1 ricovero ogni 1000.4 Per entrambe le forme, l’incidenza è tre volte superiore nel sesso femminile rispetto al maschile
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