1,720,954 research outputs found
Flekkbarking av furu (Pinus sylvestris L.) : effekter på vedens kjemiske forsvar og råteresistens
No full textFlekkbarking av furu (Pinus sylvestris) utløser en reaksjon i treet som gjør at yteveden blir mer holdbar mot nedbrytere. Observasjoner av flekker på tømmervegger tyder på at flere av Norges eldre bygninger er bygget av trær som har vært flekkbarket, og disse bygningene ser ut til å ha tålt tidens tann ekstra godt. Med forventet fuktigere klima i fremtiden, en økende interesse for naturlig holdbare materialer og et ønske om å minske bruken av biocider, kan flekkbarking kanskje bli en del av fremtidens «impregnering». Den tekniske årsaken til den økte holdbarheten er fortsatt uklar, men det er flere studier som tyder på at stilbenene pinosylvin (PS) og pinosylvinmonometyleter (PSM) spiller en viktig rolle. I dette studiet ble kjemisk forsvar, med fokus på PS og PSM, analysert på flekkbarkede trær og ubehandlede kontrolltrær. Trærne kom fra to forsøksfelter, ett på Dovre og ett i Romedal, og prøvene ble hentet ut ett år etter flekkbarking. Den kjemiske analysen ble gjort med HPLC og vedens soppresistens ble analysert med en modifisert EN-113 test.
Det var få signifikante forskjeller mellom flekkbarkede trær og kontrolltrær i den kjemiske analysen. Den eneste signifikante endringen var en økning av PSM i yteveden i trær fra Dovre. Råtetesten gav få signifikante forskjeller før og etter flekkbarking. Trærne fra Dovre viste tendens til høyere innhold av stilbener i yteveden enn trærne fra Romedal, men prøvene fra Romedal viste likevel bedre motstand mot soppen. Kjernevedprøvene fra Romedal viste også en tendens til bedre soppresistens enn de fra Dovre, tross relativt likt innhold av stilbenene. Dette kan tyde på at det er andre forskjeller enn de vi har testet i dette studiet som er viktigere for soppresistensen i furuved
Systematic debarking of Scots pine (Pinus sylvestris L.) : effects on chemical defence and rot resistance of the wood
Full text linkFlekkbarking av furu (Pinus sylvestris) utløser en reaksjon i treet som gjør at yteveden blir mer holdbar mot nedbrytere. Observasjoner av flekker på tømmervegger tyder på at flere av Norges eldre bygninger er bygget av trær som har vært flekkbarket, og disse bygningene ser ut til å ha tålt tidens tann ekstra godt. Med forventet fuktigere klima i fremtiden, en økende interesse for naturlig holdbare materialer og et ønske om å minske bruken av biocider, kan flekkbarking kanskje bli en del av fremtidens «impregnering». Den tekniske årsaken til den økte holdbarheten er fortsatt uklar, men det er flere studier som tyder på at stilbenene pinosylvin (PS) og pinosylvinmonometyleter (PSM) spiller en viktig rolle. I dette studiet ble kjemisk forsvar, med fokus på PS og PSM, analysert på flekkbarkede trær og ubehandlede kontrolltrær. Trærne kom fra to forsøksfelter, ett på Dovre og ett i Romedal, og prøvene ble hentet ut ett år etter flekkbarking. Den kjemiske analysen ble gjort med HPLC og vedens soppresistens ble analysert med en modifisert EN-113 test.
Det var få signifikante forskjeller mellom flekkbarkede trær og kontrolltrær i den kjemiske analysen. Den eneste signifikante endringen var en økning av PSM i yteveden i trær fra Dovre. Råtetesten gav få signifikante forskjeller før og etter flekkbarking. Trærne fra Dovre viste tendens til høyere innhold av stilbener i yteveden enn trærne fra Romedal, men prøvene fra Romedal viste likevel bedre motstand mot soppen. Kjernevedprøvene fra Romedal viste også en tendens til bedre soppresistens enn de fra Dovre, tross relativt likt innhold av stilbenene. Dette kan tyde på at det er andre forskjeller enn de vi har testet i dette studiet som er viktigere for soppresistensen i furuved.Systematic debarking of Scots pine (Pinus sylvestris) induces defensive reactions in the tree, which gives the sapwood properties comparable to the well-known durable heartwood. This wood is often called “lightwood”. Traces of wounds like these are found on several old wooden buildings in Norway, and these buildings seem to withstand the everchanging climate. Global warming is predicted to change the Norwegian climate to the wetter, and durable building materials will be essential in the future. Regulations on use of biocides are constantly narrowing, and awareness of carbon footprint of materials are increasing worldwide. The interest in wooden materials are therefore increasing, and development of new environmentally friendly techniques for increasing durability has become a subject of attention. Maybe systematic wounding and formation of “lightwood” is the new technique? The technical reason for the observed increased durability is not ascertained, but a few studies imply that the stilbenes pinosylvin (PS) and pinosylvinmonomethylether (PSM) play an important role. In this study we analysed the chemical defence (PS and PSM) and rot resistance in trees that had been systematically wounded and compared them to untreated control trees. The trees were from two sites in Norway, one at Dovre and one in Romedal, and samples were gathered one year after the wounding. The chemical analysis was done with HPLC and the rot-test was done by a modified EN-113 test.
In the chemical analysis, there were few differences between the wounded trees and control. The only significant difference was an increase in PSM in the sapwood in trees from Dovre. There were also few differences in decay resistance in the rot-test. Sapwood samples from Dovre had slightly higher concentrations of the stilbenes than those from Romedal, but the samples from Romedal demonstrated slightly better decay resistance. The heartwood samples from Romedal also demonstrated better decay resistance than those from Dovre, although they had similar concentrations of the stilbenes. The results imply that there are other differences than the ones tested in this study that is of greater importance in decay resistance of Scots pine wood.Riksantikvaren - Direktoratet for kulturminneforvaltningM-S
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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