Thesis (PhD) - Swinburne University of Technology, Faculty of Engineering and Industrial Sciences, 2007. / A thesis submitted for the degree of Doctor of Philosophy, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, 2007. Typescript. Includes bibliographical references.

Thesis (MScFor)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: Unextracted (control) and PHWe Eucalyptus grandis wood chips were pulped at 15% active alkali (AA) and 1% antraquinone (AQ). Another batch of wood chips were then inoculated with fungal co-cultures of Aspergillus flavipes and Pycnoporus sanguineus. FCCi wood chips were incubated for four weeks; one PHWe inoculated experimental treatment was incubated for three weeks. The full pulping cycle (160 min) was used to digest the experimental treatments with the exception of one lot of PHWe wood chips that were pulped for 150 minutes. A further experimental treatment of PHWe wood chips was cooked at a reduced AA charge of 14% and 1% AQ. Analysis of variance (ANOVA) of the data from all the experimental treatments was conducted and the differences within the experimental treatments were determined using Statistica (v7, 1984–2006). The F-value (Fischer distribution) and the p-value as well as a non-parametric test known as the Mann-Whitney procedure was tested at the 95% confidence limit. For a further enhancement of the 95% confidence limit the screened yield data was tested by the Bootstrap method. Scanning electron micrographs clearly demonstrated the changed structure and appearance of the chip cross-sectional area after the different pretreatments. Although the mean average results of all the screened pulp yields showed no significant statistical difference (p> 0.05), differences in screened yield of up to 2.5% were obtained. All the weighted means of the rejects showed a significant difference (p < 0.05). Other pulp properties like shive content, chemical consumption, Kappa number, handsheet brightness and strength tests showed mixed results i.e. rejected or accepted the hypothesis (p> or =or < 0.05). The hypothesis that the combined PHWE and FCCI of wood chips would further increase the pulp yield had to be rejected. It is however anticipated that the combination of PHWE with successive co-culture fungal pretreatment would be very beneficial in obtaining higher pulp yields for fully bleached chemical pulp. Further research would be required to test this assumption. This investigation confirmed the expected beneficial effects of combined PHWE and FCCI pretreatments of wood chips on the strength properties. In addition the combined treatment also improved the initial bonding strength potential of the unbeaten fibres. / AFRIKAANSE OPSOMMING: Onbehandelde en met onder druk, warm water uitgeloogde Eucalyptus grandis houtspaanders is respektiefwelik met 15% aktiewe alkali (AA) en 1% antrakinoon (AQ) verpulp. Hierdie is dan met swamkokulture van Aspergillus flavipes en Pycnoporus sanguineus inokuleer en respektiewelik vir drie en vier weke inkubeer. Onder druk uitgeloogde houtspaanders is ook vir 150 minute verpulp by 15% AA 1% AQ en by ‘n verminderde AA van 14%. Pulpevaluasies is uitgevoer op alle eksperimentele behandelinge. Alle onder druk uitgeloogde en met swamkokultuur inokuleerde houtspaanders het ‘n laer pulpopbrengs, uitskot, skilferinhoud, Kappanommer en ‘n hoër RAA en helderheid opgelewer in vergelyking met die vars houtspaanders. Die vars en warm water uitgeloogde houtspaanders het soortgelyke pulpopbrengs opgelewer. ‘n Variansieanalise (ANOVA) van die data van alle eskperimentele behandelings is uitgevoer gebruikmakende van Statistica (V7, 1984 – 2006). Die F-waarde (Fischer-verspreiding) an die p-waarde so wel as ‘n parametriese toets (Mann-Whitney prosedure) is getoets by ‘n 95% betroubaarheidsgrens. Vir ‘n verdere verhoging van die 95% betroubaarheidsgrens van die pulpopbrengs, is die beskikbare data weer getoets met die Bootstrap-metode. Alle gemiddelde pulpopbrengswaardes het geen beduidende statistiese verkil opgelewer nie (p>0.05), alhoewel verskille van tot 2.5% in pulpopbrengs verkry is. Alle gemiddelde uitskotwaardes het ‘n beduidende verskil getoon (p<0.05). Die ander pulpeienskappe soos skilferinhoud, verbruik aan chemikalieë, Kappagetal, handvel helderheid en sterktewaardes het gemengde resultate opgelewer maw verwerping of aanvaarding van die hipotese p> or =or < 0.05. Die hipotese dat die gekombineerde PHWE en FCCI van die houtspaanders die pulpopbrengs verder sou verhoog moes verwerp word. Daar word egter verwag dat die kombinasie van PHWE met opeenvolgende swamkokultuur behandeling baie voordelig sou wees op die pulpopbrengs van ‘n ten volle gebleikte chemiese pulp. Verdere navorsing is nodig om hierdie veronderstelling te toets. Die ondersoek het die verwagte woordelige effek van die gekombineerde PHWE en FCCI voorbehandelings van die houtspaanders op die papierstrkte-eienskappe bevestig. Bo en behalve dit, het die gekombineerde behandeling ook die aavanklikte bindsterkte potensiaal van die ongeklopte vessels verbeter.

In many species of birds, males have complex song repertoires, which are used in the context of breeding. The succinct rationale of the research done in this thesis is the following paradox; assuming that song repertoires are costly to produce and store, why do males have repertoires of songs rather than a single song? A possible reason is that, if only males of good quality or in good condition are able to produce these repertoires, good quality males would outweigh the costs of the repertoire by increased benefits in mating success. I studied this issue in a population of willow warblers (Pbylloscopus trocbilus). I found some evidence that repertoire size was correlated with male quality. Male age was found to correlate with repertoire size, and there was a positive correlation between repertoire size and survival. The probability of a male having an offspring recruiting into the population was also correlated with repertoire size. Number of fledglings was positively correlated with repertoire size, even when the effect of arrival date was taken into account. However, female choice bore no relation to repertoire size. Females patted first with early arriving males. Females did not use repertoire size either when choosing extra-pair partners. Another characteristic, song length, seemed to be behind this choice, and males with short songs were more likely to be cuckolded. The effects of song repertoires in male-male competition were examined by means of a playback experiment. The results did not provide conclusive evidence of an effect of repertoire in male-male competition. Taken together, the evidence gathered in this thesis suggests that, although repertoire size correlates with several measures of male quality in this species, the maintenance of this trait does not seem to be based on a disproportionally higher mating benefit.

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Orientador: Mauro Augusto Demarzo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-21T13:52:31Z (GMT). No. of bitstreams: 1 Santos_SoniaRoseCostaAraujodos_M.pdf: 5172089 bytes, checksum: bd3d1a4e9a708a64ccb8763971508ae2 (MD5) Previous issue date: 2012 / Resumo: A variabilidade natural, a trabalhabilidade, as propriedades físicas e mecânicas, bem como características de utilidades estéticas e ambientais da madeira, encantam até hoje os pesquisadores no mundo. Ao longo dos séculos, a arte de secar a madeira em fornos foi sendo desenvolvida junto com as descobertas científicas e tecnológicas, com a associação de conhecimento elétrico e mecânico, chegando-se ao que temos hoje em dia. As razões fundamentais para secagem da madeira são: melhorar a estabilidade dimensional; redução de peso; possibilitar o processamento secundário; assegurar um melhor desempenho em uso de seus produtos. O objetivo deste trabalho é descrever a evolução dos equipamentos de secagem de madeira, considerando suas vantagens e desvantagens, por intermédio de visitas a empresas que possuem secadores, e entrevistar especialistas na área de secagem de madeira (nacionais e internacionais). Concluiu-se que os operadores são peças fundamentais para conduzir eficientemente o programa de secagem e interagir as variáveis do processo conseguindo um produto de qualidade para o uso estrutural ou manufaturado. E que, as propriedades físico-mecânicas da madeira devem ser consideradas para que seja alcançado um melhor desempenho do produto em uso / Abstract: The natural variability, the workability, the physical and mechanical properties as well as aesthetic characteristics and environmental utilities of the timber, enchant up today the researchers in the world. Over the centuries, the art of dry wood in stoves was being developed with the scientific and technological discoveries, with the combination of electrical and mechanical knowledge, reaching up to what we have today. The fundamental reasons for drying wood are: improved stability, weight reduction, enabling secondary processing; ensure better performance in use of its products. The objective of this paper is to describe the evolution of wood drying equipment considering its advantages and disadvantages, through visits to companies that have dryers, and interviewed experts in the field of wood drying (national and international). It was concluded that operators are fundamental to efficiently conduct the drying program and interacting process variables getting a quality product for structural use or manufactured. And that the physical and mechanical properties of the wood, should be considered, order to reach a better performance of the product in use / Mestrado / Estruturas / Mestre em Engenharia Civil

The first part of this thesis deals with recognition of wood fingerprints extracted from timber surfaces. It presents different methods to track sawn wood products through an industrial process using cameras. The possibility of identifying individual wood products comes from the biological variation of trees, where the genetic code, environment, and breakdown process means that every board has a unique appearance. Wood fingerprint recognition experiences many of the same challenges as found in human biometrics applications.  The vision for the future is to be able to utilize existing imaging sensors in the production line to track individual products through a disordered and diverging product flow. The flow speed in wood industries is usually very high, 2-15 meters per second, with a high degree of automation. Wood fingerprints combined with automated inspection makes it possible to tailor subsequent processing steps for each product and can be used to deliver customized products. Wood tracking can also give the machine operators vital feedback on the process parameters.  The motivation for recognition comes from the need for the wood industry to keep track of products without using invasive methods, such as bar code stickers or painted labels. In the project Hol-i-Wood Patching Robot, an automatic scanner- and robot system was developed. In this project, there was a wish to keep track of the shuttering panels that were going to be repaired by the automatic robots.  In this thesis, three different strategies to recognize previously scanned sawn wood products are presented. The first approach uses feature detectors to find matching features between two images. This approach proved to be robust, even when subjected to moderate geometric- and radiometric image distortions. The recognition accuracy reached 100% when using high quality scans of Scots pine boards that had more than 20 knots.  The second approach uses local knot neighborhood geometry to find point matches between images. The recognition accuracy reached above 99% when matching simulated Scots pine panels with realistically added noise to the knot positions, given the assumption that 85% of the knots could be detected. The third approach uses template matching to match a small part of a board against a large set of full-length boards. Cropping and heavy downsampling was implemented in this study. The intensity normalized algorithms using cross-correlation (CC-N) and correlation coefficient (CCF-N) obtained the highest recognition accuracy and had very similar overall performance. For instance, the matching accuracy for the CCF-N method reached above 99% for query images of length 1 m when the pixel density was above 0.08 pixels/mm. The last part of this thesis deals with the detection of thin cracks on oak flooring lamellae using ultrasound-excited thermography and machine learning. Today, many people manually grade and detect defects on wooden lamellae in the parquet flooring industry. The last appended paper investigates the possibility to use ensemble methods random forests and boosting to automate the process. When friction occurs in thin cracks they become warm and thus visible for a thermographic camera. Several image processing techniques were used to suppress noise and enhance likely cracks in the images. The best ensemble methods reached an average classification accuracy of 0.8, which was very close to the authors own manual attempt at separating the images (0.83).

<p> The southern pine species group is the main softwood resource used in the U.S, and the majority of southern pine is used in lumber production. The use of lumber in structural purpose requires feasible strength and stiffness grading method ensuring characteristics allowable stress values. The stiffness and strength of most of southern pine lumber is assessed using visual grading system. The objective of this study was to evaluate a production weighted sample of 2 &times; 4, 2 &times; 6, 2 &times; 8, and 2 &times; 10 No. 2 grade southern pine lumber collected across its geographic range. The results of this research show a snapshot of the material commercially sold in the southern U.S. region. Over one third of the specimens contained pith, and had an average mean value of 4.6 for number of rings per inch (RPI) and 43.8% for latewood (LW). The overall specific gravity (SG), modulus of elasticity (MOE) and modulus of rupture (MOR) were 0.54, 10.1 GPa, and 41.7 MPa, respectively. The allowable design bending strength (F_b) for 2 &times; 4, 2 &times; 6, 2 &times; 8, and 2 &times; 10 was 11.2, 9.2, 8.1, and 7.1 MPa, respectively. Specimens containing no pith, RPI higher or equal then 4.0, and LW higher or equal then 33.0% were greater in MOE and MOR. The effect of grading controlling characteristics of the material was also studied. The presence of knots had the most significant impact on mechanical properties. Specimens with wane and shake had greater SG, MOE, MOR, F_b values than specimens with others grading controlling characteristics. The mean values found for RPI, LW, and SG met the requirements recommended for southern pine No. 2 lumber. The MOE and F_b values found therein met the previous and the new allowable design value. The results of this research can be used to identify and to select the best variables to improve the prediction of bending properties of visually graded lumber.</p><p>

<p> Although incipient fungal decay of wood may be difficult to detect early, it causes a significant decrease in wood strength. Developing a reliable method of decay identification to overcome wood replacement costs by non-destructive methods is necessary. This study investigates a possibility of identifying fungal volatile organic compounds (VOCs) as means of fungal detection using solid phase micro-extraction (SPME) coupled with gas chromatography&ndash;mass spectrometry (GC-MS). </p><p> Volatile emissions from two brown rot (<i>Gloeophyllum trabeum</i> and <i>Postia placenta</i>) and two white rot (<i>Trametes versicolor</i> and <i>Irpex lacteus</i>) fungi on pine and aspen and their profiles related to wood mechanical strength and mass loss were investigated over 12 weeks. Principal component analysis of VOCs spectra differentiated volatiles from decayed and sound wood. Volatiles from two fungal species revealed distinct patterns of early and late degradation stages. SPME combined with GC-MS showed promissing results for non-destructive identification of incipient decay in wood structures.</p><p>

My work has a strong formal quality and a deep relation to minimalism without ever buying into it. Through tension and inserting my personal experience into the making of the work, but not always within the meaning of the work, I leave the viewer to draw their own conclusions.