1,721,588 research outputs found
Modelling Of The Thermal Behavior Of Walls And Floors In Contact With The Ground
Get PDFOne of the most complex configuration to model in detail, both in the dynamic simulation of buildings and in the analytical quasi steady-state calculations, is the thermal dispersion through the walls and the floor in contact with the ground. The problem consists in determining the boundary conditions of the external wall surface directly exposed to the soil, whose temperature cannot be considered undisturbed. Different studies, both experimental and numerical, have been carried out in the last decades in order to determine the ground boundary conditions, some of which have been used to elaborate the technical standard EN ISO 13370. This standard gives some indications about the conditions to be considered in the use of quasi steady-state methods and within the dynamic simulation. The evaluation of the simulation software in the specific context of the ground heat transmission, has also driven the IEA to define a specific series of validation cases, the BESTEST In-depth ground coupled heat transfer tests. The present research aim is to test implement reliable calculation procedures for the thermal dispersion through the building envelope towards the ground, in dynamic simulation modelling systems. In this work, a test case of the EN ISO 13370 standard has been modelled with FEM codes, both in steady-state conditions and also in periodic external conditions. Different types of floor have been considered, with different thickness and position of the insulation layer. The results have been compared with those calculated following the prescriptions of the standard EN ISO 13370
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Simplifield calculations of heat losses from building via the ground in accordance with PN-EN ISO 13370
No full textZnajomość strumienia strat ciepła przez grunt jest potrzebna do obliczania szczytowej mocy cieplnej i sezonowego zapotrzebowania na ciepło. Podczas gdy przenikanie ciepła przez przegrody pełne w kontakcie z powietrzem zewnętrznym można rozpatrywać jako ustalone, jednowymiarowe przewodzenie ciepła, z uwzględnieniem - w formie dodatkowych członów - wpływu mostków cieplnych punktowych i liniowych, to w przypadku kontaktu z gruntem problem przenoszenia ciepła staje się bardziej skomplikowany. Obliczenia zgodnie z PN-EN ISO 13370 Przenoszenie ciepła przez grunt. Metody obliczania są bardzo pracochłonne. W artykule podano metodę uproszczonych obliczeń strat ciepła z budynku przez grunt dającą wyniki zgodne z PN-EN ISO 13370 i dogodną do ręcznego kalkulatora. Wyprowadzono użyteczne wzory dla podłogi typu "płyta na gruncie", podłogi podwieszonej i podłogi nieogrzewanego podziemia.The knowledge of heat transfer through the ground is necessary for calculation of heat peak power and of seasonal space heating requirements. Heat transfer through building opaque elements in contact with external air can be considered as stationary, one dimensional heat flow, with giving consideration to the influence of thermal bridges (point and linear one). However, in case of contact with the ground, the problem of heat transfer becomes more complicated. The calculations according to PN-EN ISO 13370:2001 Heat transfer via the ground - Calculation methods are very laborious. The paper deals with the method of simplified calculations of heat losses from building via the ground giving the results in conformity with PN-EN ISO 13370 and suitable for manual calculator. The useful formulae are derived for slab on the ground floor, raised floor and floor of unheated basement
Variations on the Author
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Similar temperature responses suggest future climate warming will not alter partitioning between denitrification and anammox in temperate marine sediments
Get PDFAuthor Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Global Change Biology 23 (2017): 331-340, doi:10.1111/gcb.13370.Removal of biologically available nitrogen (N) by the microbially mediated processes
denitrification and anaerobic ammonium oxidation (anammox) affects ecosystem N availability.
Although few studies have examined temperature responses of denitrification and anammox,
previous work suggests that denitrification could become more important than anammox in
response to climate warming. To test this hypothesis, we determined whether temperature
responses of denitrification and anammox differed in shelf and estuarine sediments from coastal
Rhode Island over a seasonal cycle. The influence of temperature and organic C availability was
further assessed in a 12-week laboratory microcosm experiment. Temperature responses, as
characterized by thermal optima (Topt) and apparent activation energy (Ea), were determined by
measuring potential rates of denitrification and anammox at 31 discrete temperatures ranging
from 3 to 59°C. With a few exceptions, Topt and Ea of denitrification and anammox did not differ
in Rhode Island sediments over the seasonal cycle. In microcosm sediments, Ea was
somewhat lower for anammox compared to denitrification across all treatments. However,
Topt did not differ between processes, and neither Ea nor Topt changed with warming or carbon
addition. Thus, the two processes behaved similarly in terms of temperature response, and this
response was not influenced by warming. This led us to reject the hypothesis that anammox is
more cold-adapted than denitrification in our study system. Overall, our study suggests that
temperature responses of both processes can be accurately modeled for temperate regions in the
future using a single set of parameters, which are likely not to change over the next century as a
result of predicted climate warming. We further conclude that climate warming will not directly
alter the partitioning of N flow through anammox and denitrification.This material is based upon work supported by the National Science Foundation
under Grant No. OCE-0852289 to JJR and OCE-0852263, OCE-0927400 and OCE1238212 to
AEG, and Rhode Island Sea Grant to JJR.2017-05-2
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