http://hdl.handle.net/1957/7864 Collection contains scholarly output of student majors in the Oregon State University College of Forestry. Search the Channel search http://ir.library.oregonstate.edu/jspui/simple-search http://hdl.handle.net/1957/12529 Title: Weibull diameter distribution models for managed stands of Douglas-fir in Washington and Oregon<br/><br/>Authors: Eng, Helge<br/><br/>Abstract: The two-parameter Weibull function was used topredict forest stand diameter distributions and growth.Diameter distribution models were developed for even-agedDouglas-fir stands, 20 to 40 years old, in Oregon andWashington.In order to test if the two-parameter Weibullfunction can adequately describe the diameterdistributions of such stands, maximum likelihoodestimated parameters of the two parameter Weibullfunction were compared with observeddiameterdistributions.Two sets of models were developed. The first setof models predicted the diameter distributions ofunthinned forest stands from stand variables. Models were developed to predict each of the two parameters of the Weibullfunction from stand variables. The Weibullfunction with the two estimated parameters became thediameter distribution model for the stand. The second setof models predicted the growth of a stand of trees afterthinning. A Weibull diameter distribution model wasdeveloped for a forest stand after a growth period. Theparameters of the Weibull function were estimated fromstand variables at the beginning of the growth period andthe length of the growth period.Results showed that the two-parameter Weibullfunction can describe the diameter distributions of even-agedstands of Douglas-fir, 20 to 40 years old, in Oregonand Washington. The diameter distribution model forunthinned stands predicted the observed diameterdistributions in an independent data set quite well. Thediameter distribution model for a thinned stand after agrowth period gave a satisfactory prediction for 93percent of the observed diameter distributions in theindependent data set.The two-parameter Weibull function in this studygave at least as good results as that which has beenobtained with the three-parameter Weibull function inprevious studies.<br/><br/>Description: Graduation date: 1986 Fri, 28 Aug 2009 16:38:13 GMT http://hdl.handle.net/1957/11989 Title: Lead-user research in the wood window value chain<br/><br/>Authors: Kamke, Kathryn Jean<br/><br/>Abstract: Lead-user research is a relatively new marketing research technique, and it has not seen much use in the forest sector. Lead-user research is designed to capture not just the needs of the customer in their own voice but also to involve actual users of goods and/or services in their development. Lead-users are those individuals who are on the leading-edge in adopting new products and services and who expect to realize the most benefit from these new products and services. This expectation is what drives lead-users to innovate. The qualitative study described here identifies and explores the perspectives of lead-users in the wood window industry. These users identified what they liked or did not like about existing products and services as well as desirable new products and services. Qualitative measures were used to document and summarize the results. Findings from this study outline various opportunities and challenges for the introduction of regionally targeted and green/environmental products, processes and services, thereby demonstrating the value of applying to lead-users for product development concepts. However, this study also highlights the challenges in using the lead-user method, including the varying definitions of a lead-user and the subjective nature of categorizing someone as a lead-user. These findings show that while there are multiple opportunities for window manufacturers to innovate and, in so doing, create superior customer value, there is also a need for greater familiarity with the lead-user method so that it can be effectively applied.<br/><br/>Description: Graduation date: 2010 Wed, 08 Jul 2009 22:26:47 GMT http://hdl.handle.net/1957/11816 Title: Functional decreases in hydraulic and mechanical properties of field-grown transgenic poplar trees caused by modification of the lignin synthesis pathway through downregulation of the 4-coumarate:coenzyme A ligase gene<br/><br/>Authors: Voelker, Steven L.<br/><br/>Abstract: Society uses massive quantities of wood fiber in production of paper, and demand for fiber is projected to increase further as production of biofuels from fermentation of plant cellulosic materials increases. Because these end uses generally require the costly step of removing of lignin, wood with reduced or more easily extracted lignin has long been a goal of plant biotechnologists. However, there is little information on how reduction of lignin affects wood properties, tree development, and survival, especially in field environments. We studied a gene that had been previously reported to substantially reduce lignin content and improve biomass production in poplar. An antisense, xylem expressed version of the Pt4CL1 gene that encodes 4-coumarate:coenzyme A ligase (4CL) was inserted into hybrid poplar (Populus tremula x alba, INRA 717-1B4) and the growth and physiology of 14 transgenic lines (i.e., independent gene insertion events) was assessed over two growing seasons. Transgenic lines had 30-70% reductions in 4CL RNA expression in young shoots. This corresponded to 5-45% reduction in lignin as indicated by total monomer release through thioacidolysis and/or nitrobenzene oxidation. Only three transgenic lines with modest (>10%) reductions in lignin content sustained adequate growth and had normal tree form. Trees from five lines with severely reduced lignin formed up 24-60% of the stem cross-sectional area in brown colored wood that was essentially non-conductive to water, presumably due to the ectopic deposition of non-lignin phenolics and associated tyloses that occluded vessels. Across all genotypes, the transgenic lines had up to a three-fold increase in tensionwood, 40% lower modulus of elasticity, 25% lower modulus of rupture, 45% reduced resistance to xylem embolism (P₅₀), and a 60% increase in stem taper. Comparable patterns in wood density in lines that were lower in lignin by up to 9% by mass was compensated for by a 3% increase in polysaccharide content associated with tensionwood and a 6% increase in the deposition of extractives. Taken together, these data suggest that extensive field testing, ecophysiology, and wood quality evaluations are critical components of research and development on lignin-modified tree crops.<br/><br/>Description: Graduation date: 2009 Thu, 21 May 2009 22:58:59 GMT http://hdl.handle.net/1957/11580 Title: Non-destructive evaluation of veneer using optical scanning and ultrasonic stress wave analysis systems<br/><br/>Authors: DeVallance, David B.<br/><br/>Abstract: Non-destructive commercial ultrasonic grading provides laminated veneer lumber (LVL) manufacturers a means for sorting veneer based on average ultrasonic propagation time (UPT) and/or average dynamic modulus of elasticity (MOEd). While this may provide reliable estimations of modulus of elasticity (MOE), little is known about the influence of veneer defects on strength properties of veneer and LVL. It was hypothesized that inclusion of veneer defect and growth ring pattern measures, obtained via optical scanning, would improve veneer and LVL static tensile MOE and strength (Ft) property predictions. Non-destructive and destructive testing on Douglas-fir (Pseudotsuga menziesii) veneer and LVL was performed to evaluate improvements in veneer and LVL tensile MOE and Ft property predictions. Various models based solely on density, optical, and ultrasonic system measures, as well as various combinations of systems measures, were developed for individual veneer and LVL property predictions. The integration of optical and ultrasonic measures (i.e., combined system model) best explained the variation in veneer static tensile MOE and Ft. The combined system model best predicted average LVL static tensile MOE. LVL static Ft was best predicted by using overall average veneer measures comprising the entire LVL material, rather than the average of individually predicted veneer Ft used in assembling the LVL. Specifically, the combined system model, which included various specific average defect, growth ring pattern, and MOEd measures comprising the LVL material, best explained the variation in LVL static Ft values (R2 = 0.65) as compared to all other models. Results from this study suggest improved veneer and LVL Ft predictions can be achieved by integrating the existing ultrasonic and optical systems already existing in many manufacturing facilities. Additionally, the optical model which included average defect, growth ring, and density measurements within the LVL material better explained the variation in LVL static Ft values (R2 = 0.58), as compared to the MOEd (R2 = 0.52) and UPT (R2 = 0.31) models. As a result, the developed optical system showed promise as a suitable veneer grading system. A need was identified for future research on optically grading full-size veneer sheets and manufacturing and testing full-size LVL billets.<br/><br/>Description: Graduation date: 2009 Thu, 23 Apr 2009 22:58:59 GMT