1,720,984 research outputs found
Thermal performance of two innovative materials applied to historic walls: aerogel insulation and radiation selective coating
No full textDefinition of an experimental procedure with the hot box method for the thermal performance evaluation of inhomogeneous walls
No full textResearch and development of high thermal insulation materials for the construction sector requires an accurate characterization of the wall's performance, since that is the main causes of thermal exchanges between the internal and external boundaries. This paper presents a test procedure developed within the EU Project EFFESUS for evaluating the steady-state thermal performance of a masonry wall. A large-scale mock-up of the inhomogeneous wall was tested in a guarded hot box (GHB) apparatus before and after the application of an aerogel-based material. The methodology proposed in this paper is structured in the following steps: (i) definition of the wall geometry and the percentage of stone and mortar, using walls' photographic records and geometrical surveys; (ii) precise thermal characterization of the material used; (iii) hygrothermal assessment procedure based on infrared technology (IRT) survey, gravimetric test, and monitoring of the internal relative humidity (RH); (iv) steady-state and dynamic thermal simulation; and (v) detailed set-up of the test using the data retrieved from the thermal surveys and simulations. According to the results of IRT surveys and the dynamic simulations, the mock-up was divided into thermal homogeneous parts, verifying the uniformity of the surface temperature and the heat flux in an isothermal area. This approach was validated both for low and high energy performance walls. Results show that the thermal flux was reduced to one third after the application of the aerogel. (C) 2018 Elsevier B.V. All rights reserved
Economic assessment of the internal insulation of historic buildings using the “cost optimality” approach
No full textEconomic Assessment of the Internalinsulation of Historic Buildings Using the "Cost Optimality" Approach
No full textThe Directive 2010/31 UE (EBPD) introduces the Nearly Zero Energy Buildings
linked to cost optimality, where energy benefits are closely linked to economic
benefits. This methodology is applicable both to new and existing buildings, but
although it has been largely applied to existing buildings, there are only few
examples on historic buildings. Contrariwise, it would be appropriate to develop a
specific methodology for the economic valorization of heritage buildings,
considering also the preservation of their historic values. On the other hand, it
could develop shared information and examples of historic “reference
buildings”(i.e. on discount rate, type of proper methodology between financial or
macro-economic schemes). For this reason, the case studies become an important
starting point to create common typological and repeatable models for applying
this methodology. This research aims at evaluating the economic benefits of energy
retrofit of a traditional historic masonry, using the "Cost Optimality” methodology.
The research is structured into the following parts: (i) assessment of the heritage
value; (ii) definition of the type of masonry; (iii) selection of the insulation
systems; (iv) assessment of the energy benefits related to the insertion of various
insulation materials; (v) evaluation of the Life Cycle Costing; (vi) evaluation of the
optimal insulation performance and cost-effectiveness; and (vii) comparison of
energy consumption and Life Cycle Cost to define the most appropriate
interventions for the historic wall
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
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