1,721,044 research outputs found
Characterising the creation of defects in large scale vacuum assisted resin infusions in the marine industry
No full textUtilisation of the Vacuum Assisted Resin Infusion (VARI) process has increased in recent years for the manufacture of large scale components for the transport industry. Quality control and repeatability are two key areas where the VARI process requires greater understanding due to the scale of the infusions. The marine industry has a history of being at the cutting edge of large scale composite manufacturing. This research focusses on utilising the processes and knowledge at Princess Yachts International (PYI) to monitor and analyse the process variability and uncertainty for large scale VARIs. A detailed process review was conducted at PYI to evaluate the level of process monitoring and variability as well as the defect controls that are used in industry. Core samples were extracted from infusions where surface visible defects had been recorded. The core samples were analysed using Micro Computed Tomography (µ-CT) to generate a three-dimensional reconstruction of the defects. The location and structure of the defects indicated matrix failure towards the mould surface of the component, an area which is not monitored during the VARI process. Having identified a requirement to monitor the manufacturing process, a review of available sensors was conducted identifying Fibre Bragg Grating (FBG) fibre optics as the most suitable monitoring method. The sensors measured the residual stress development during resin curing as well as the high loads exerted on the component during demoulding which were five times larger than during the infusion and resin curing process. The measured strains were lower than the failure strain of the resin suggesting the presence of defects that result in premature matrix failure. A novel approach to monitoring resin flow was then developed to analyse the through thickness resin flow progress using µ-CT. Both monolithic and sandwich laminates were analysed both in-situ and exsitu to evaluate the effect of variable laminate layup. The results further identified the high degree of variability during the infusion caused by changes in laminate schedule and the transition from sandwich to monolithic sections
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
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
Spectral Broadening of 25 fs Laser Pulses via Self-Phase Modulation in a Neon filled Hollow Core Fibre
No full textThe goal of this work was the realisation of a setup for spectral broadening andsubsequent compression of 25 fs laser pulses provided by a commercial Ti:Sapphire basedCPA laser system by means of the hollow core ?bre chirped mirror compressor technique.For the spectral broadening a vessel containing the hollow waveguide ?lled with a noble gasserving as the nonlinear medium was set up and an alignment procedure was developed.Neon was chosen as the nonlinear medium for the self-phase modulation of the pulses.With this setup spectral broadening, su?cient for supporting sub 5 fs pulses, was observed.The spectra at di?erent input energies and neon gas pressures were measured and thestability of these and their respective Fourier transform-limited pulses determined in orderto ?nd an operating point. For the compression of the self-phase modulated pulses achirped mirror compressor was designed and set up, but not tested yet. The layoutofasingle-shot intensity autocorrelator capable of estimating the pulse duration of sub 10 fspulses was given
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
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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