1,720,954 research outputs found
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
Preparo, caracterização e aplicação de materiais sorventes para microextração organica
No full textOrientador : Fabio AugustoTese (doutorado) - Universidade Estadual de Campinas, Instituto de QuimicaDoutorad
Mobility of disulfoton, its degradation products and of triadimenol in Red-Yellow Latosol
No full textO objetivo deste trabalho foi avaliar a movimentação do dissulfoton, de seus produtos de degradação e do triadimenol, estudando-se a percolação desses compostos em amostras de solo da região de Viçosa, MG. No estudo da percolação, foram preparadas 10 séries de colunas de tubo de PVC empacotadas com solo, onde foi aplicada uma dosagem equivalente a 70 kg/ha do produto comercial contendo os princípios ativos dissulfoton e triadimenol. Sobre as colunas, foram feitas simulações de chuva equivalente a 35 mm de precipitação pluviométrica durante 90 dias, em intervalos de 10 dias. A avaliação da mobilidade desses compostos foi feita pela análise dos seus resíduos no solo e na água percolada. Inicialmente, foram realizados testes para avaliar a eficiência da técnica de extração do dissulfoton, de seus produtos de oxidação e do triadimenol em amostras de solo e de água. Os compostos foram extraídos das amostras de solo com acetona e das amostras de água com diclorometano, permitindo analisar, simultaneamente, todos os compostos com rendimentos satisfatórios. A quantificação dos resíduos presentes nos extratos das amostras foi feita em um cromatógrafo a gás com detector por ionização em chama. Os resultados indicaram que os princípios ativos dissulfoton e triadimenol não foram lixiviados abaixo dos 5 cm da coluna de solo. O dissulfoton rapidamente foi oxidado para dissulfoton sulfóxido e dissulfoton sulfona e, após 60 dias, para análogo oxigenado do dissulfoton sulfona. O dissulfoton sulfona percolou os 15 cm da coluna de solo, sendo detectado na água de percolação após 40 dias de experimento, mas os teores encontrados na água ficaram em torno de 1%. O análogo oxigenado do dissulfoton sulfona foi detectado após 60 dias ao longo da coluna de solo em quantidades variando entre 11 e 18% da dosagem de dissulfoton aplicada, mas não o foi na água percolada.The purpose of this study was to evaluate the motion of disulfoton, its degradation products and triadimenol, investigating the percolation of these compounds in soil samples from the region of Viçosa, State of Minas Gerais, Brazil. In the percolation investigation, 10 series of PVC columns were packed with soil, to which were applied a dosage equivalent to 70 kg/ha of the commercial product, containing the active principles of disulfoton and triadimenol. Over the columns rain simulations were carried out equivalent to a rainfall of 35 mm, during 90 days, at 10 days intervals. The evaluation of the mobility of these compounds was done by the analysis of their residues in the soil and in the percolated water. Initially, essays to evaluate the efficiency of the extraction techniques for disulfoton, its oxidation products, and triadimenol, in soil and water samples, were carried out. The compounds were extracted from the soil samples with acetone and from the water samples with diclorometane, allowing simultaneous analysis of all compounds with satisfactory yields. The quantification of the residues present in the sample extracts was carried out with a gas chromatograph with a flame ionization detector. The results indicated that the active principles of disulfoton and triadimenol were not leached below 5 cm of the soil column. The disulfoton was rapidly oxidized to disulfoton sulfoxide and disulfoton sulfone and, after 60 days, to the oxygenated analog of disulfoton sulfone. The disulfoton sulfone percolated the 15 cm of the soil column, being detected in the percolation water after 40 days into the experiment, but the contents found in the water were around 1%. The oxygenated analog of disulfoton sulfone was detected after 60 days along the soil column in quantities varying from 11 to 18% of the applied dose, but was not detected in the percolation water.Conselho Nacional de Desenvolvimento Científico e Tecnológic
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
