1,720,983 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
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
PREPARATION OF TEMPERATURE-RESPONSIVE POLYMER BY GRAFTING OF N-<i>ISOPROPYLACRYLAMIDE</i> (NIPAAM) ONTO SOLID WASTE CASSAVA
Get PDFIn this study, cellulose prepared from solid waste of cassava industry was functionalized with N-isopropylacrylamide (NIPAAm) using grafting technique with the aid of cerium (IV) as initiator, to obtain temperature responsive polymer. In this research, several factors influencing the grafting process and the characteristics of the grafted polymer were investigated, including concentration of monomer and initiator, temperature, reaction time, and solvent used. The functionality of native and grafted cellulose was analyzed using FTIR spectroscopic technique and the response of grafted polymer toward temperature was evaluated with water absorption experiment. Increased concentration of both monomer and initiator was found to promote percentage of polymerization, and utilization of organic solvent was found to enhance the percentage of polymerization. From absorption experiment, it was found that the produced polymer was responsive toward temperature of its environment, as indicated by higher water adsorption at temperature of 5 °C compared to that adsorbed at temperature of 50 °C
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
CHARACTERISTICS OF RICE HUSK SILICA GRAFTED 4-VINYL PYRIDINE
Get PDFThis study was carried out to investigate the grafting of4-Vinyl Pyridine (4-VP) on silica prepared from rice husk, with the main aim to study wether the 4-VP grafted retains its characteristics. For this purpose, the grafted silica was analysed using FTIR spectroscopic method, followed by testing of the sample for solvent adsorption, Cu2+ adsorption from solution, and bacterial inhibitions, since 4-VP has been known to possess such properties. The FTIR analysis revealed that under the experimental conditions applied, the 4-PV was well grafted onto silica surface. The success of grafting was also supported by the results of solvent adsorption, which indicate the increase in adsorption capacity with increased percent of grafting and higher adsorption capacity toward polar solvent. The same supports are also provided by the ability of the sample to adsorp results of Cu2+ adsorption from solution, and the ability of the sample to inhibit the microorganism growth.
Keywords: Graft copolymerization, rice husk silica, 3-methacryloxypropyl trimethoxysilane, 4-vinyl pyridine, microorganism growth inhibitio
CHARACTERISTICS OF RICE HUSK SILICA GRAFTED 4-VINYL PYRIDINE Karakteristik Silika Sekam Padi Tergrafting 4-Vinil Piridin
Get PDFABSTRACT
This study was carried out to investigate the grafting of4-Vinyl Pyridine (4-VP) on silica prepared from rice
husk, with the main aim to study wether the 4-VP grafted retains its characteristics. For this purpose, the grafted
silica was analysed using FTIR spectroscopic method, followed by testing of the sample for solvent adsorption, Cu2+
adsorption from solution, and bacterial inhibitions, since 4-VP has been known to possess such properties. The
FTIR analysis revealed that under the experimental conditions applied, the 4-PV was well grafted onto silica surface.
The success of grafting was also supported by the results of solvent adsorption, which indicate the increase in
adsorption capacity with increased percent of grafting and higher adsorption capacity toward polar solvent. The
same supports are also provided by the ability of the sample to adsorp results of cif+ adsorption from solution, and
the ability of the sample to inhibit the microorganism growth. .
Keywords: Graft copolymerization, rice husk silica, 3-methacryloxypropyltrimethoxysilane, 4-vinyl pyridine,
microorganismgrowth inhibition
Transesterification of Coconut Oil Using Dimethyl Carbonate and TiO2/SiO2 Heterogeneous Catalyst
Get PDFIn this study, transesterification of coconut oil with dimethyl carbonate (DMC) for preparing biodiesel has been studied using TiO2/SiO2 as heterogeneous catalyst, with the main purpose to investigate the effect of molar ratio of DMC to oil. The product was analyzed by GC-MS to identify the fatty acid methyl esters (FAMEs) composting the biodiesel. The significant role of the DMC to oil ratio was observed in this study, in which the oil conversion was found to increase with increasing molar ratio of DMC : Oil, with the highest percent of conversion of 88.44%. The GC-MS analysis revealed the presence of methyl esters in accordance with the composition of coconut oil commonly reported. Formation of FAMEs was verified by 1H-NMR spectroscopic analysis, which also suggested that some of the fatty acids remain unconverted into biodiesel. The biodiesel produced was found to have kinematic viscosity of 2.4 mm2/S at 40 °C, flash point of 103 °C, and cetane number of 54.</jats:p
Transesterification of Coconut Oil Using Dimethyl Carbonate and TiO2/SiO2 Heterogeneous Catalyst
Get PDFIn this study, transesterification of coconut oil with dimethyl carbonate (DMC) for preparing biodiesel has been studied using TiO2/SiO2 as heterogeneous catalyst, with the main purpose to investigate the effect of molar ratio of DMC to oil. The product was analyzed by GC-MS to identify the fatty acid methyl esters (FAMEs) composting the biodiesel. The significant role of the DMC to oil ratio was observed in this study, in which the oil conversion was found to increase with increasing molar ratio of DMC : Oil, with the highest percent of conversion of 88.44%. The GC-MS analysis revealed the presence of methyl esters in accordance with the composition of coconut oil commonly reported. Formation of FAMEs was verified by 1H-NMR spectroscopic analysis, which also suggested that some of the fatty acids remain unconverted into biodiesel. The biodiesel produced was found to have kinematic viscosity of 2.4 mm2/S at 40 °C, flash point of 103 °C, and cetane number of 54
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
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