1,720,961 research outputs found
Physical properties of four year old hybrid aspen kraft pulp
Get PDFThe demand for quality pulpwood in the paper industry is increasing rapidly while supplies from traditional sources are declining. Studies have shown that short-rotation forestry and species hybridization offer acceptable raw materials for pulp and paper production. Hybrid poplars are the most promising materials because of their fast growth rate and their suitability for pulp. The objectives of this study were to determine the kraft pulp properties of three new hybrid aspens and to compare them with other hybrid poplars. The three experimental hybrids were P. alba x P. tremula , P. alba x P. alba Bolleana, and P. alba x P. grandidentata. Debarked materials were pulped with 17.5% active alkali and 25% sulfidity with a 4:1 liquor to wood ratio at a maximum temperature 170 °C for 1.5 hours. The average specific gravity and fiber length also were determined. Results indicated that the P. alba x P. tremula hybrid had a specific gravity (0.366) comparable to other hybrid poplars. All three new hybrids had a significantly longer average fiber length than other poplar hybrids, ranging from 0.886 to 0.912 mm. Results also showed that the beaten pulp of the P. alba x P. tremula hybrid had superior tensile, burst, and tear strengths compared to those of the other two new hybrids as well as the kraft pulps of other juvenile hybrids. The P. alba x P. tremula hybrid had an average fiber length of 0.912 mm, 52.9% pulp yield, and the pulp could be readily beaten. It is concluded that P. alba x P. tremula is a promising hybrid for pulp production
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
NDE of lumber and natural fiber based products with air coupled ultrasound
Get PDFDue to the porous nature of wood and natural fiber based products, conventional fluid or gel coupled ultrasonic inspection is unsuitable. Air‐coupled ultrasonic transmission scanning, being non‐contact, is ideally suited for inspecting lumber, wood and natural fiber based products. We report here several successful applications of air‐coupled ultrasound for the inspection of wood. Air‐coupled ultrasonic scan at 120 kHz can easily detect “sinker‐stock” lumber in which bacterial damage of ray tissue cells had occurred during anaerobic pond storage. Channels in ash lumber board caused by insect bore were imaged in transmission scan. Delamination and material inhomogeneities were mapped out in manufactured wood and natural fiber products including medium density fiberboards, compression molded shredded waste wood with formaldehyde resin, and acoustic panels molded with kenaf fibers. The study has demonstrated some of the capabilities of air‐coupled ultrasound in the NDE of forest products.Copyright 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
This article appeared in AIP Conference Proceedings 1211 (2010): 1533–1540 and may be found at http://dx.doi.org/10.1063/1.3362250.</p
Utilization of Agriculture Fibers
Get PDFTo meet the enormous future demand for forest products due to anticipated global population growth, not only should we practice sustainable forestry and maximize raw material use and extend useful life of products by means of new technologies, we also need to maximize use of every available fiber resource.</p
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