1,721,013 research outputs found
Neutronic Analysis of a Plutonium Burner PWR Partially Fed with Inert Matrix Fuel
Get PDFThe plutonium coming from dismantled warheads and that already stockpiled coming from spent fuel reprocessing have raised many concerns related to proliferation resistance, environmental safety and economy. The option of disposing of plutonium by fission has been discussed and many proposals for plutonium burning in a safe and economical manner have been put forward. The advantages of utilizing the pressurized water reactors (PWRs) for plutonium disposition are the well developed and reliable technology and their diffusion. The mixide-oxide (MOX) fuel form, that is used for plutonium recycling in power reactors, is well developed. Nevertheless, to eliminate the production of additional plutonium during irradiation, an improved design fuel was analysed, which replace the natural or depleted uranium with inert oxides.
This type of fuel offers the potential for annihilation of the major portion of the plutonium: commercial PWRs operating in a once-through cycle scheme could burn more than 98% of the loaded Pu-239 and more than 73% of the overall initially loaded reactor-grade plutonium. The plutonium still left in the spent fuel was quality-poor and then offered a better proliferation resistance. Power peaking problems could be faced with the adoption of burnable absorbers: zirconium diboride coating in the form of integral fuel burnable absorber (IFBA) appeared particularly suitable. In spite of a reduction of the overall plutonium loaded mass by a factor 3.7, there was not evidence of an increase of the Minor Actinides radiotoxicity after a time period of about 25 years
Biliary complications after liver transplantation: current perspectives and future strategies
No full textImportance: Liver transplantation (LT) is a life-saving therapy for patients with end-stage liver disease and with acute liver failure, and it is associated with excellent outcomes and survival rates at 1 and 5 years. The incidence of biliary complications (BCs) after LT is reported to range from 5% to 20%, most of them occurring in the first three months, although they can occur also several years after transplantation.Objective: The aim of this review is to summarize the available evidences on pathophysiology, risk factors, diagnosis and therapeutic management of BCs after LT.Evidence Review: a literature review was performed of papers on this topic focusing on risk factors, classifications, diagnosis and treatmentFindings: Principal risk factors include surgical techniques and donor's characteristics for biliary leakage and anastomotic biliary strictures and vascular alterations for nonanastomotic biliary strictures. MRCP is the gold standard both for intra- and extrahepatic BCs, while invasive cholangiography should be restricted for therapeutic uses or when MRCP is equivocal. About treatment, endoscopic techniques are the first line of treatment with success rates of 70-100%. The combined success rate of ERCP and PTBD overcome 90% of cases. Biliary leaks often resolve spontaneously, or with the positioning of a stent in ERCP for major bile leaksConclusions and Relevance: BCs influence morbidity and mortality after LT, therefore further evidences are needed to identify novel possible risk factors, to understand if an immunological status that could lead to their development exists and to compare the effectiveness of innovative surgical and machine perfusion techniques
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
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
- …
