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1	Measuring Tree Growth by Modeling Multi-Temporal LiDAR Frew, Michael S 17 August 2013 (has links) Crown volume is defined as the geometric space occupied by the crown. Crown volume and the change (growth) of crown volume over time can be an important part of multi-temporal forest analyses but is expensive and time consuming to obtain through conventional forest survey methods for large, remote areas. LiDAR-derived crown volume growth was compared to an expected amount of crown volume growth for 220 Douglasir trees in the Panther Creek, Oregon watershed. A paired t-test between expected crown volume growth and the LiDAR-derived crown volume growth resulted in a p-value of 0.85. Regression procedures between expected crown volume and LiDAR-derived crown volume in 2008 and 2012 resulted in R2 values of 0.45 and 0.53, respectively. LiDAR measured change in crown volume over time was not significantly different than the expected amount of change. With further research, multi-temporal LiDAR could become a viable tool for forest analyses. crown volume remote sensing Douglasir
2	The Effects of Species, Adhesive Type, and Cure Temperature on the Strength and Durability of a Structural Finger Joint Vrazel, Matthew Eric 03 August 2002 (has links) This research project was conducted to evaluate the effects of adhesive type, wood species, and cure temperature on the strength and durability properties of a finger joint. The adhesives were a resorcinolormaldehyde(RF),polyurethane/aqueous emulsion polymer (PU/AEP), and a resorcinolormaldehyde/soy-isolate honeymoon system. The species of wood were keruing (Dipterocarpus spp.), southern pine (Pinus spp.), and Douglasir (Pseudotsuga menziesii). The cure temperatures of the adhesives were ambient (26-35° C, 78-95° F) and elevated (43-49° C, 110-120° F). Joints were subjected to three test procedures; a tension test, a bending test, and a bending test following an accelerated aging procedure. The response variables measured for each of the bending tests included modulus of rupture, modulus of elasticity, and percent wood failure. The response variables measured for the tension tests were tensile strength and percent wood failure. The RF adhesive performed the best in flexural and tensile strength of the three adhesives studied. However in most cases, the PU/AEP adhesive could be considered a comparable system. Given adequate adhesive performance, strength and stiffness of the joints studied were dependent on density of the wood species, with keruing having the greatest density. finger joint end joint structural wood adhesives keruing southern pine Douglasir resorcinolormaldehyde polyurethane soy hydrolyzate aqueous emulsion polymer
3	Bolstering Pine Lumber Value Through Statistical Analysis And Nondestructive Testing Owens, Frank Charles, IV 11 August 2017 (has links) In or around 2010, a nationwide reevaluation of the allowable properties for southern pine dimension lumber was initiated. This led to a 2013 reduction in the design values of visually graded southern pine dimension lumber and a resulting decrease in its commercial and utility value. This change compelled researchers and industry professionals to ponder what could be done to shore up the value of solid-sawn southern pine products going forward and potentially increase design values if appropriate. In pursuit of this question, this dissertation looks closely at three areas: 1) the possibility this reduction in mechanical performance is not merely limited to southern pine structural lumber but can also be observed in other solid-sawn softwood products and species, 2) flaws that might exist in commonly utilized statistical models for estimating allowable properties in lumber, and 3) the feasibility of using existing technologies to begin to compensate for the economic and/or utility losses attributed to the recent reduction in design values. This work is comprised of an introduction, a conclusion, and three independent content chapters utilizing a variety of statistical techniques to investigate whether strength and stiffness reduction might also be occurring in southern pine (and Douglasir) utility crossarms, evaluate the propriety of using a Weibull distribution model for estimating allowable properties in dimension lumber, and gauge the suitability of nondestructive testing methods for potentially identifying high-value premium grades in solid-sawn softwood products. bivariate Gaussian-Weibull distribution mixed bivariate normal distribution skew normal distribution 3-parameter beta distribution 2-parameter Weibull distribution mixed normal distribution normal distribution grading nondestructive Douglasir southern pine modulus of rupture modulus of elasticity bending stiffness mill run strength lumber Crossarms pseudo-truncated Weibull distribution lumber property distribution

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