Thesis (M.S.)--Oregon State University, 1996. / Typescript (photocopy). Includes bibliographical references (leaves 162-166). Also available on the World Wide Web.

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Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xx, 211 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 208-211).

Abstract This thesis describes the application of Low Coherence Interferometry (LCI) and Optical Coherence Tomography (OCT) in paper measurements. The developed measurement system is a combination of a profilometer and a tomographic imaging device, which makes the construction versatile and applicable in several paper measurement applications. The developed system was first used to measure the surface structure of paper. Different grades of paper were selected to provide maximum variation in surface structure. The results show that the developed system is capable of measuring grades of paper from rough base paper to highly coated photo printing paper. To evaluate the developed system in surface characterization, the roughness parameters of five laboratory-made paper samples measured with the developed system and with a commercial optical profilometer were compared. A linear correlation was found with roughness parameters Ra and Rq. Next, the surface quality of paper was evaluated using LCI, a Diffractive Optical Element Based Glossmeter (DOG), and a commercial glossmeter. The results show linear correlation between Ra and gloss measured with the commercial glossmeter. The roughness Ra and averaged gloss measured with the DOG didn't give such a correlation, but a combination of these techniques provided local properties of gloss and surface structure, which can be used to evaluate the local surface properties of paper. In the next study, determination of the filler content of paper using OCT is discussed. The measurement results show clear correspondence of the slope of the averaged logarithmic fringe signal envelope and the filler content. The last studies focus on 2D and 3D imaging of paper using OCT and begin with imaging of a self-made wood fiber network. The visibility of the fibers was clear. Next, several refractive index matcing agents are studied by means of light transmittance and OCT measurements to find the best possible agent for enhancing the imaging depth of OCT in paper. Benzyl alcohol was found to have the best possible combination of optical, evaporation, and sorption characteristics, and it is applied in 2D and 3D visualizations of copy paper.

Medium density fiberboard (MDF) production uses thermomechanically refined fiber processed under shear with high pressure steam. The industry evaluates fiber quality with visual and tactile inspection, emphasizing fiber dimensions, morphology, and bulk density. Considering wood reactivity, the hypothesis is that a variety of chemical and physical changes must occur that are not apparent in visual/tactile inspection. An industry/university cooperation, this work studies effects of refining energy (adjusted by refiner-plate gap) on fiber: size, porosity, surface area, surface and bulk chemistry, fiber crystallinity and rheology, and fiber interaction with amino resins. The intention is to reveal novel aspects of fiber quality that might impact MDF properties or process control efficiency, specific to a single industrial facility. In cooperation with a North American MDF Douglas fir plant, two refining energies were used to produce resin and additive-free fibers. Refining reduced fiber dimensions and increased bulk density, more so at the highest energy. Thermoporosimetry showed increases in sub-micron scale porosity, greatest at the highest energy. Mercury intrusion porosimetry (MIP) revealed porosity changes on a higher dimensional scale. Brunauer-Emmett-Teller gas adsorption and MIP showed that refining increased specific surface area, more so at the highest energy. Inverse gas chromatography showed that the lowest refining energy produced surfaces dominated by lignin and/or extractives. The highest energy produced more fiber damage, revealing higher energy active sites. A novel rheological method was devised to study fiber compaction and densification; it did not distinguish fiber types, but valuable aspects of mechano-sorption and densification were observed. Refining caused substantial polysaccharide degradation, and other degradative effects that sometimes correlated with higher refining energy. Lignin acidolysis was detected using nitrobenzene oxidation, conductometric titration of free phenols, and formaldehyde determination. Formaldehyde was generated via the C2 lignin acidolysis pathway, but C3 cleavage was the dominant lignin reaction. Observations suggested that in-line formaldehyde monitoring might be useful for process control during biomass processing. According to rheological and thermogravimetric analysis, lignin acidolysis was not accompanied by repolymerization and crosslinking. Lignin repolymerization must have been prevented by the reaction of benzyl cations with non-lignin nucleophiles. This raises consideration of additives that compete for lignin benzyl cations, perhaps to promote lignin crosslinking and/or augment the lignin network with structures that impart useful properties. Fiber/amino resin interactions were studied with differential scanning calorimetry (DSC) and X-ray diffraction (XRD). All fiber types, refined and unrefined, caused only a slight increase in melamine-urea-formaldehyde (MUF) resin reactivity. Generally, all fiber types decreased the enthalpy of MUF cure, suggesting fiber absorption of small reactive species. But DSC did not reveal any dependency on fiber refining energy. According to XRD, all fiber types reduced crystallinity in cured MUF, more so with refined fiber, but independent of refining energy. The crystallinity in cured urea-formaldehyde resin was studied with one fiber type (highest refining energy); it caused a crystallinity decrease that was cure temperature dependent. This suggests that resin crystallinity could vary through the thickness of an MDF panel. / PHD / Medium density fiberboard (MDF) is a wood-based composite which is widely used for making kitchen cabinets and furniture. In the process of making MDF, wood particles are softened under steam pressure and under high temperature and pressure, inside a refiner, mechanically cut into wood fibers. Wood fibers are then mixed with adhesive and additives then hot-pressed and form the final board. In the MDF industry, wood fiber quality has significant effect on final board properties and is evaluated based on visual and tactile inspections. The research hypothesis is that, during the refining, a variety of chemical and physical changes must occur that are not apparent in visual/tactile inspection. An industry/university cooperation, this work studies effects of refining energy (adjusted by refiner-plate gap) on fiber: size, porosity, surface area, surface and bulk chemistry, fiber crystallinity and rheology, and fiber interaction with adhesive. The intention is to reveal novel aspects of fiber quality that might impact MDF properties or process control efficiency, specific to a single industrial facility. It was found that refining had significant effect on wood fiber properties: increased surface area, porosity, and changed the surface energy; and also on wood fiber chemistry: significant degradation in wood fiber main chemical components: poly saccharides and lignin. These changes also had effect on fiber/adhesive interaction. Therefore the hypothesis was confirmed that MDF fiber quality must involve more than a simple visual/tactile evaluation and the effect of refining can be detected on other fiber quality aspects. However more research needs to be conducted to test and find feasible new methods for fiber quality evaluation.

En réponse à une forte croissance démographique mondiale, et notamment africaine, il est nécessaire d’anticiper les besoins de la population en terme de bâtiment. Il s’agit alors de développer des matériaux alternatifs présentant des performances multi-physiques adéquates tout en ayant un faible impact sur l’environnement. Ce travail porte sur l’élaboration et la caractérisation de composites utilisables comme produits constructifs de partition (cloison, faux plafonds). La sélection des matières premières intègre des critères de développement durable, en considérant leur disponibilité locale mais également leur empreinte en terme d’épuisement des ressources (matériaux recyclés ou bio-sourcés). Les liants utilisés sont le plâtre, l’amidon de pomme de terre et l’amidon de manioc. Les charges sont la fibre de bois, la ouate de cellulose et les granules de papiers, pour une valorisation originale en matériau de construction. Les performances des composites développés sont évaluées d’un point de vue mécanique, hygrique, thermique et en terme de résistance au feu. Ces travaux ont montré la faisabilité et l’intérêt de tels composites. Ceux-ci peuvent notamment être utilisés pour leur qualité de régulateur hygrique et de correcteur thermique. / Due to strong global population growth, and particularly African, the population’s needs in terms of building have to be anticipated. The aim is to develop alternative materials with adequate multiphysical performances and low impact on the environment. This work investigates the elaboration and characterization of composites to be used as constructive partition products (partitions, false ceilings). The selection of raw materials takes into account sustainable development criteria, considering both the local availability of materials and their footprint in terms of resource depletion (recycled or bio-sourced materials). The binders used are plaster, potato starch and cassava starch. The loads are wood fiber, cellulose wadding and paper granules, for an original valorisation in building material. The performances of the developed composites are evaluated from a mechanical, hygric, thermal and fire resistance point of view. This work has shown the feasibility and the interest of such composites. These can in particular be used for their quality of hygric regulator and thermal corrector.

The global climate situation today is strained, leading to both the need and the interest for the use of non-polluting materials to increase in the building sector. In Sweden, this sector accounts for about 18% of the country’s total domestic emissions of greenhouse gases, of which 55% occurs from heat losses in buildings. The need for increasing energy efficiency and using well-insulating and environmentally friendly materials can therefore be considered necessary. Bio-based materials such as wood fiber insulation are becoming increasingly more available on the market. These materials have an environmental advantage compared to mineral wool but are still being used on a smaller scale. The purpose of this study is to analyze and examine technical differences and other reasons why wood fiber insulation is being used to a lesser extent compared to mineral wool. Both a literature and an interview study were conducted to identify these reasons. The results showed differences in thermal conductivity and fire resistance between wood fiber insulation and mineral wool. Both types of mineral wools performed better in both categories. Several other factors besides technical differences were discovered to affect the use of wood fiber insulation. Respondents described the building sector as conservative, and slow in the process of implementing new materials. Concerns were raised about performance regarding fire and the durability of the wood fiber insulation over time. Price, low or non-existing interest amongst customers were two other factors highlighted in the interview study. All respondents viewed wood fiber insulation as an untested material and expressed a need for better documentation and guidelines to feel safe using or recommending the product. It was found in this study that the awareness and knowledge about the material amongst the interviewers was quite diverse. This may be due to low interest, low demand, or lack of marketing regarding wood fiber insulation. / Klimatsituationen i världen idag är ansträngd, och både intresset och behovet av att utveckla och använda miljövänliga material och produkter inom byggsektorn ökar. I Sverige står denna sektor för cirka 18% av landets totala inhemska utsläpp av växthusgaser och av dessa utgör omkring 55% uppvärmning för byggnader. Den största mängden energi går förlorad genom otillräckligt isolerade byggnader, vilket understryker behovet av att åtgärda dessa brister. Idag används huvudsakligen mineralullsisolering i Sverige för byggnation. Produktmarknaden erbjuder däremot också biobaserad isolering, där träfiberisolering är ett exempel. Träfiberisoleringen har fler miljömässiga fördelar jämfört med mineralull, men nyttjas i mindre skala. Denna studie syftar därför till att skapa förståelse och undersöka varför träfiberisolering används i mindre utsträckning. Målet är att identifiera samt redovisa tekniska och andra skäl till att användningen är begränsad. Två metoder tillämpades i studien för att kunna nå dess syfte och mål. Den ena var en litteraturstudie där skillnader mellan träfiberisolering och mineralull jämfördes på en teknisk nivå. Den andra var en intervjustudie med åtta nyckelaktörer i byggbranschen, som genomfördes för att erhålla en uppfattning om vilka faktorer som påverkade valet av isolering. Den tekniska jämförelsen utgick ifrån kategorierna värmeisolerande förmåga, samt brand-, fukt- och ljudisolerande aspekter. Fyra olika isoleringsprodukter från fyra olika tillverkare studerades, varav två var träfiberisolering och två var oorganiska mineralullstyper, i form av stenull och glasull.   Studiens tekniska jämförelse visade att träfiberisoleringen presterade sämre än mineralullen både gällande värmekonduktivitet och värmemotstånd. Den brandtekniska klassen för mineralull var klass A1, vilket är den högsta, medan träfiberisoleringen hade den lägsta klassificeringen med en E-klass. För fuktegenskapen ånggenomsläpplighet visade båda typer av mineralull samma värde, medan träfiberisoleringen hade lägre värden. Vattenabsorptionen för korttid och långtid, samt den ljudisolerande förmågan, kunde inte jämföras eftersom ingen prestanda var deklarerad i dessa kategorier för någon av produkterna. Utöver jämförelsen av teknisk prestanda undersöktes även skäl till att byggbranschens aktörer ofta väljer att använda mineralull hellre än träfiberisolering. Det konstaterades att flera faktorer än de tekniska skillnaderna påverkar i frågan. Flera aktörer påpekade att branschen var konservativ och det var en långsam process att implementera nya material. En annan faktor som lyftes av aktörerna var oro kring brandförmågan och hur den tekniska prestandan håller över tid. Prisskillnaden, samt att intresset för träfiberisolering hos beställare var lågt eller obefintligt, var två ytterligare anledningar som identifierades. Samtliga aktörer uttryckte också uppfattningen om träfiberisoleringen som ett obeprövat material med för låg dokumentationsgrad för att känna trygghet i att använda produkten. Fler anledningar kring träfiberisoleringens användning upptäcktes än de som från början fanns hypoteser kring. En av de större orsakerna var osäkerhetsfaktorer kring dokumentation och tekniska egenskaper för träfiberisolering. Andra skäl var branschens konservatism och långsamma utveckling, behov av trygghet i prestanda av garantiskäl, och viss misstro gällande tillverkares uttalanden om produkten. Generellt visade aktörerna spridd medvetenhet och kunskap kring materialet, vilket kan bero på lågt intresse, låg efterfrågan eller bristande marknadsföring av träfiberisolering.

The objective of the study is to improve the interfacial adhesion between the wood fibers and thermoplastic matrix. Efforts were also directed towards improving manufacturing processes so as to realize the full potential of wood fibers as reinforcing fillers. Chemical coupling plays an important role in improving interfacial bonding strength in wood-polymer composites. A novel compatibilizer with isocyanate functional group was synthesized by grafting m-Isopropenyl –α –α –dimethylbenzyl-isocyanate (m-TMI) onto isotactic polypropylene using reactive extrusion process. The compatibilizer was characterized with respect to its nature, concentration and location of functional group, and molecular weight. There are two main process issues when blending polymers with incompatible filler: (1) creating and maintaining the target morphology, and (2) doing so with minimum degradation of fillers. A 28mm co-rotating intermeshing twin screw extrusion system was custom built and the design optimized for (1) blending biological fibers with thermoplastics, and (2) for melt phase fictionalization of thermoplastics by reactive extrusion. To assess the effect of inclusion of wood fibers in polypropylene composites, a series of polypropylene wood fiber/wood flour filled composite materials having 10 to 50 wt % of wood content were prepared using the co-rotating twin screw extrusion system. m-TMI-g-PP and MAPP were used as coupling agents. Addition of wood fibers, at all levels, resulted in more rigid and tenacious composites. The continuous improvement in properties of the composites with the increasing wood filler is attributed to the effective reinforcement of low modulus polypropylene matrix with the high modulus wood filler. Studies on were also undertaken to understand effect of particle morphology, type and concentration of coupling agent, and effect of process additives on mechanical properties. Composites prepared with m-TMI-grafted-PP were much superior to the composites prepared with conventionally used maleated polypropylene in all the cases. Non-destructive evaluation of dynamic modulus of elasticity (MoE) and shear modulus of wood filled polypropylene composite at various filler contents was carried out from the vibration frequencies of disc shaped specimens. The vibration damping behaviour of the composite material was evaluated. MoE and shear modulus were found to increase whereas damping coefficient decreased with the increasing filler content. Knowledge of moisture uptake and transport properties is useful in estimating moisture related effects such as fungal attack and loss of mechanical strength. Hence, a study was undertaken to asses the moisture absorption by wood filled polypropylene composites. Composites prepared with coupling agents absorbed at least 30% less moisture than composites without compatibilizer. Thermo-gravimetric measurements were also carried out to evaluate the thermal stability and to evaluate kinetic parameters associated with thermal degradation of wood fiber and wood flour filled polypropylene composites. The moisture absorption and thermal behaviour are described based on analytical models. High efficiency filler-anchored catalyst system was prepared by substituting of hydroxyl groups present on the cellulosic filler. The process involves immobilizing the cocatalyst onto the cellulosic filler surface followed by addition of metallocene catalyst and then polymerization of ethylene using this filler supported catalyst. The polymerization and composite formation takes place simultaneously. All the polymerization reactions were carried out in a high-pressure stirred autoclave. Effect of temperature, ethylene pressure, and cocatalyst to catalyst ratios (Al/TM ratios) were also studied. Studies on kinetics of polymerization showed that, higher Al/Zr ratio and higher temperature lead to higher polymerization rates but lower the molecular weight. A model incorporating effect of reaction parameter on polymerization rates has been developed.

Pine tree substrate (PTS) produced from freshly harvested loblolly pine (Pinus taeda L.) trees has potential for replacing or reducing the use of aged pine bark (PB) and peat moss as container substrates for horticulture crop production. The objective of this work was to determine the factors influencing nutrient availability in PTS compared to PB or peat substrates. Chapter two reports data on the response of japanese holly and azalea to fertilizer rate when grown in PTS and PB. This study demonstrated that an additional 2.4 kg·m-3 of Osmocote Plus (15N-3.9P-10K) controlled release fertilizer is required for both species when grown in PTS compared to PB. Data are reported in chapter three on the effects of fertilizer rate, substrate particle size, and peat amendment on growth and floral quality, and on post-production time-to-wilting of poinsettias. Data from this work show that PTS requires an additional 100 mg·L-1 N to grow poinsettias comparable to plants grown in peat unless the particle size of PTS was decreased or 25% peat was added, in which case no additional fertilizer was needed. Results also indicated that PTS shrinkage was similar to that of peat, and that post-production time-to-wilting in PTS plants was similar as plants grown in peat. Data in chapter four compares nitrogen (N) immobilization rates, substrate carbon dioxide (CO₂) efflux levels, and nutrient leaching in peat, PB, and PTS over time. Data from these studies indicated that more N immobilization occurs in PTS than in PB or peat and that the substrate CO₂ efflux levels (estimate of microbial activity) corresponds to N immobilization in all substrates. Nutrient availability, changes in physical and chemical properties, substrate shrinkage, and microbial activity in PTS compared to PB during long-term nursery production are reported in chapter five. Results showed that substrate nutrient levels remain lower in PTS and that pH levels of PTS decrease considerably over two growing seasons compared to PB. Results also indicate that PTS does decompose over time in containers, but substrate shrinkage of PTS is similar to that of PL and PB during crop production. / Ph. D.

The aim of my master's thesis is a project of a new apartment building on a sloped site at a level of the documentation for the structure realization. The building is partly basement with four above-ground floor. Individual floors up recede and are roofed with flat roofs. The structural system of the basement part is made up of permanent shuttering and the above-ground part is made up wall of cross laminated timber construction panels KLH. The project of the building is in accordance with the development plan of Kopřivnice and with the current street built. The work puts great emphasis on layout including security of the construction in terms of statics, architecture, energy savings and safety at utilizing the structure.