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The impact of log storage time, log size and steaming time on the veneer quality of Pinus elliottii & Pinus taeda
Get PDFThesis (MScFor)--Stellenbosch University, 2024.ENGLISH ABSTRACT: Plywood producers in South Africa historically used P. patula for veneer production. More recently, however, it became impossible to plant P. patula at lower altitudes, because of the fungal pathogen Fusarium circinatum, which causes high mortality soon after planting. Hybrids between P. patula and P. tecunumanii are now planted in these areas, and until they come into commercial production, P. elliottii and P. taeda are used as alternatives. There are increasing volumes of these two species that need to be optimized for veneer production in the coming years, while waiting for the hybrids to reach rotation age. The main question is whether the wood from different species can be processed under similar conditions as P. patula, or if species-specific processing production protocols are required.
This study investigates how log storage time, steaming time and log size (diameter class) impact the veneer quality of P. elliottii and P. taeda. Twelve different treatments, varying the three factors (log storage time, steaming time and log size) were compared within and between species. The resultant veneer from each treatment was analysed to see how the three factors impact wet recovery, peeler waste components, dryer throughput and quality recovery.
The study revealed significant differences in wet recovery between the two pine species, primarily due to their taper properties, with larger logs demonstrating better wet recovery for both species. Extended log storage negatively impacted wet recovery as blue stains were often mistaken for wane, resulting in unnecessary rounding up of logs. Logs subjected to longer storage times resulted in lower veneer grades after drying compared to those processed four weeks after felling. Steaming improved peeling performance, enhancing veneer quality despite not directly affecting wet recovery. Increasing steaming time from 8 hours to 12 hours did not have a clear impact on wet recovery, but it significantly improved the quality of the recovered veneer after drying for both species in both fresh and older logs. Larger logs generally achieved better veneer grades due to less knots, while logs stored for longer periods experienced more downgrades caused by blue stain and splitting, likely due to moisture loss.AFRIKAANSE OPSOMMING: Laaghoutprodusente in Suid-Afrika het histories P. patula vir fineerproduksie gebruik. Meer onlangs
het dit egter onmoontlik geword om P. patula op laer hoogtes te plant, as gevolg van die
swampatogeen Fusarium circinatum, wat ‘n hoë mortaliteitsyfer veroorsaak, kort na aanplanting.
Basters tussen P. patula en P. tecunumanii word nou in hierdie gebiede geplant. Totdat hulle in
kommersiële produksie kom, word P. elliottii en P. taeda as ‘n alternatief gebruik. Toenemende
volumes van hierdie twee spesies moet geoptimaliseer word vir fineerproduksie, terwyl die baster
spesies nog nie produksieouderdom bereik het nie. Die hoofvraag is of die hout van verskillende
spesies onder soortgelyke toestande as P. patula verwerk kan word, en of spesiespesifieke
verwerkingsproduksieprotokolle vereis word.
Hierdie studie ondersoek hoe stoortyd, stoomtyd en stompgrootte (deursneeklas) die fineerkwaliteit
van P. elliottii en P. taeda beïnvloed. Twaalf verskillende behandelinge, wat die drie faktore
(houtstoortyd, stoomtyd en stompgrootte) wissel, is binne en tussen spesies vergelyk. Die
gevolglike fineer van elke behandeling is ontleed om te sien hoe die drie faktore, naamlik nat
volume behoud, skillerafvalkomponente, droërdeurset en kwaliteitbehoud beïnvloed.
Die studie het beduidende verskille in nat volume behoud tussen die twee dennespesies aan die lig
gebring, hoofsaaklik as gevolg van hul tapse eienskappe, met groter stompe wat beter nat volume
behoud vir beide spesies toon. Verlengde stompberging het nat volume behoud negatief beïnvloed,
aangesien blou vlekke dikwels verwar is met afneem, wat gelei het tot onnodige afronding van
stompe. Stompe wat aan langer bergtye onderwerp is, het gelei tot laer fineergrade na droging in
vergelyking met dié wat vier weke na afkap verwerk is. Stoombehandeling het afskilverrigting en
fineerkwaliteit verbeter, dit nie nat volume behoud direk beïnvloed het nie nie. Stoombehandeling
verlenging van 8 tot 12 ure het nie ‘n beduidende impak gehad op nat volume behoud nie, maar dit
het die kwaliteit van die fineer, na droog, vir beide spesies, in beide vars asook ouers stompe
verbeter. Groter stompe het oor die algemeen beter fineergrade behaal as gevolg van minder knope,
terwyl stompe wat vir langer tydperke gestoor is, meer afgraderings ervaar het as gevolg van blou
vlek en skeuring, waarskynlik as gevolg van vogverlies.Master
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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