1,720,957 research outputs found
Mode I fracture of wood: a systematic review of experimental and numerical advances
No full textPurpose. This paper presents a systematic literature review on Mode I fracture of wood in order to identify the research trends, highlight existing gaps and guide future studies. Design/methodology/approach. The research methodology is designed in two steps: (1) bibliometric analysis and (2) publication overview. In the first step, two main databases were used to identify relevant publications and analyze research trends, historical chronology, citations and geographical distribution. While in the second step, selected studies were overviewed across different topics to determine advancements and gaps in the field.FindingsThe field is dominated by experimental research, with a growing use of mixed and numerical methods. The topics were categorized as follows: (1) established topics (wood species, test type, size effect, cracking system, growth ring effect, density and wood structure effect); (2) ongoing topics which need further investigation (heat treatment effect, moisture content effect, numerical modelling, advanced measurement methods such as digital image correlations (DIC) and acoustic emissions (AE) and (3) unestablished topics (loading rate). After identifying the gaps, it is suggested further simulations on heat treatment, the impacts of moisture, improving the application of DIC, AE and their combination, considering the fiber bridging phenomena in the simulations, developing more 3D models, performing experimental campaign for better understanding the loading rate effect and finally more experimental and/or numerical studies on cyclic loading under different testing conditions. Originality/value. The report provides previous findings on mode I fracture of wood and can be regarded as a comprehensive reference for guiding further experimentations and/or simulations to fill in the gaps
Numerical Simulation of the Heat Dissipation During the Fatigue Test
No full textFatigue is an irreversible process accompanied by the heat dissipation which is significant when the transition from anelastic to inelastic strains happens. In view of this, in the last years, the heat dissipation has been accepted as an appropriate damage indicator of the material.The estimation of the heat dissipation can be obtained by detecting the surface thermal footprint of the specimen by using thermography-based techniques. However, the energy dissipation as heat is highly sensitive to the environmental and test conditions and the microstructure status. Therefore, the experimental measurement is always associated with some inaccuracies and only provides an estimation of the heat dissipated during fatigue.This paper is mainly focused on the numerical modeling of the heat dissipation performed by COMSOL Multiphysics software in order to investigate the factors that can affect the estimation of the heat source by means of thermography. The obtained results have been compared with an analytical solution derived from the one-dimensional heat equation. This study can provide valuable insights about the shape of the heat sources produced during the cyclic loading and differences associated with thermographic measurements and actual values, which are the main goals of this work
Fatigue limit estimation of metals based on the thermographic methods: A comprehensive review
No full textInfrared thermography has been under review in the last 30 years due to its versatility and potential in the detection of the thermal signature associated with intrinsic energy phenomena due to dissipative processes, specifically those relying on mechanical fatigue. Nowadays, it is a well-established technique that can support mechanical and structural engineers to implement a damage-tolerant design, assess the residual life, and finally characterize the fatigue behavior of materials. The aim of this work is to review all thermography-based approaches and procedures for fatigue limit estimation by rapid tests, drawing considerations on the applicability of thermal methods in fatigue assessment of mechanical components, proposing the capabilities of different thermal indices in fatigue assessment, and discussing the pros and cons of each method as well as the open points. On one hand, this review intends to sum up what has already been done in the field; on the other hand, it provides a guideline to direct new researches toward issues that should be resolved or understood
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
No full textWe 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
No full textWe 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
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
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