1,721,035 research outputs found
Chloride Ion Penetration into Cracked UHPFRC During Wetting-drying Cycles
No full textThe subject of this paper is the extent to which, during wetting–drying cycles, chloride ions can penetrate Ultra-high-Performance Fibre Reinforced Cementitious Composites (UHPFRC) specimens subjected to combined mechanical and environmental load. Pre-cracking was obtained by subjecting prismatic specimens (40 × 40 × 60mm3) to four-point bending until a predefined crack opening displacement (COD) is reached, using a dedicated test setup. Three target CODs were studied: 300, 350 and 400 µm. Exposure to a concentrated chloride solution (3.5% NaCl) was used as an environmental load. Specimens we subjected to wetting–drying cycles for one year. After this exposure period, the chloride penetration was characterised both qualitatively (by colourimetric analysis with silver nitrate) and quantitatively (by determining the chloride profile). The effect of damage level on chloride penetration and its impact on structures durability is discussed in the current paper.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Materials and Environmen
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
Development of new solutions for steel and concrete lightweight slabs
No full textDissertação de mestrado integrado em Engenharia Civil (área de especialização em Perfil de Estruturas e Geotecnia)Visando a construção económica de edifícios que utilizam pavimentos mistos em aço e betão,
a presente dissertação tem como principal objetivo estudar o comportamento desse sistema de
pavimentos, tirando o máximo partido dos dois materiais.
Esse sistema de viga mista congrega uma laje mista que é composta por uma chapa perfilada
sobre a qual se betona a camada de betão, uma viga metálica formada por dois perfis “C”
enformados a frio, e um conector metálico, que tem como principal função garantir a conexão
entre a viga metálica e laje mista. A presença dos elementos de conexão tem por objetivo
transmitir esforços de corte longitudinal que se desenvolvem entre a viga metálica e a laje e
reduzir ou limitar o movimento relativo entre estes dois elementos.
O conector metálico aqui estudado será de dois tipos, um realizado com uma chapa nervurada
do tipo Xadrez e outro realizado com uma chapa lisa recortada ou indentada. Após a betonagem
da laje, a ligação entre os dois materiais, aço e betão, será garantida por um destes dois tipos de
conectores.
Para estudar o comportamento do sistema misto sujeito à flexão foi inicialmente desenvolvida
uma Ferramenta de Cálculo no software Microsoft Excel, que permitiu a realização de uma
análise paramétrica às dimensões da viga metálica, do conector e da laje de betão e ainda uma
análise paramétrica ao caso de um sistema idêntico com laje maciça. Esta ferramenta de cálculo
foi validada tendo em conta cálculos realizados manualmente e também cálculos automáticos
realizados a partir da própria Ferramenta, considerando a variação sucessiva das posições do
eixo neutro.
Posteriormente, recorreu-se ao software Atena 3D onde foram construídos modelos numéricos
representativos das vigas mistas com os dois tipos de conectores. Após a construção destes
modelos, realizou-se uma análise de sensibilidade, através da variação de diversos parâmetros.
Essa análise permitiu perceber a influência de parâmetros relevantes no comportamento dos
modelos testados e tirar conclusões quanto ao comportamento esperado durante a realização
dos ensaios experimentais.
Por fim, modelou-se os provetes das vigas mistas com os dois tipos de conectores, para futuros
ensaios à flexão e para ensaios do tipo push-out, utilizando para o efeito o software Tekla
Structures. Os modelos desenvolvidos no software Teckla Structures têm por objetivo servir de
apoio ao fabrico das peças metálicas, à colocação de armaduras, ao fabrico e colocação de
cofragens, à betonagem e ainda à montagem do setup dos ensaios e realização dos mesmos.This dissertation aims to study the behaviour of a steel and concrete composite flooring system
that takes full advantage of both materials and provides an economic construction system.
This composite beam system gathers a composite slab, a metallic beam formed by two coldformed
"C" profiles and a steel connector, which has the main function of connecting the steel
beam and the composite slab. The composite slab includes a profiled deck on which the concrete
layer is concreted and steel reinforcement. The presence of the connecting elements guarantees
the transmission of longitudinal shear forces that are developed between the steel beam and slab
and reduces or limits slip between these two elements.
The metal connectors in study are of two types. The first one is made with a ribbed flat plate
and another with an indented flat plate. After concreting the slab, the connection between the
two materials, steel and concrete, is ensured by one of these two types of connectors.
A calculation tool was initially developed in the Microsoft Excel software, in order to study the
proposed composite system when subjected to bending behaviour. The use of the calculation
tool allowed for a parametric analysis on the dimensions of the steel beam, of the steel connector
and of the composite slab. An identical parametric analysis was also developed on a similar
system with a slab of constant thickness. This tool was validated by taking into account
calculations performed manually and also automatic calculations performed with the tool itself,
by considering the successive variation of the neutral axis position.
Later, the author used the Athena 3D software to build representative numerical models of
composite beams with two types of connectors. After the construction of these models, a
sensitivity analysis was developed, by varying several parameters. This sensitivity analysis
provided data to understand the influence of relevant parameters on the behaviour of the tested
models and to draw conclusions about the expected behaviour during the performance of
experimental tests.
Finally, the composite beams specimens were modelled with two types of connectors for future
bending tests and push-out tests, using the Tekla Structures software for this purpose. The
models developed in Tekla Structures software were designed to provide support to the
manufacture of metal parts, placing of reinforcement, the manufacture and placement of
scaffolding, the concreting and also the assembly and setup of tests
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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