Evaluation of Wood Properties of Genetically Modified Trees

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dc.contributor.advisor Ilona Peszlen, Committee Co-Chair en_US
dc.contributor.advisor Myron W. Kelly, Committee Member en_US
dc.contributor.advisor Perry N. Peralta, Committee Co-Chair en_US
dc.contributor.advisor Tasnim Hassan, Committee Member en_US
dc.contributor.advisor Bohumil Kasal, Committee Member en_US
dc.contributor.author Saralde, Teofisto Cis Jr. en_US
dc.date.accessioned 2010-04-02T18:00:16Z
dc.date.available 2010-04-02T18:00:16Z
dc.date.issued 2007-03-14 en_US
dc.identifier.other etd-11092006-110837 en_US
dc.identifier.uri http://www.lib.ncsu.edu/resolver/1840.16/1043
dc.description.abstract Two related studies were conducted for the evaluation of wood properties of genetically modified loblolly pine (Pinus taeda): first in terms of mechanical properties and then for shrinkage properties. Another study focused on the development of methods for the evaluation of the mechanical properties of small young trees. In the first study, the effect associated with genetic modification of loblolly pine was evaluated by comparing the mechanical properties of lumber from trees deficient in cinnamyl alcohol dehydrogenase (CAD) enzyme with those from wild-type trees. Small clear wood specimens were tested in static bending, compression parallel and perpendicular to the grain, tension perpendicular to the grain, and shear parallel to the grain. Results indicated that there was no significant difference between the two genotypes for all mechanical properties measured. Consequently, partially CAD-deficient loblolly pine has no significantly altered mechanical properties. In the second study, partially CAD-deficient and wild-type loblolly pine were studied for shrinkage properties. Pie-shaped samples for the determination of radial and tangential shrinkages were cut from logs. The method allows for the measurement of shrinkage for different wood types and for correction due to the effect of growth ring curvature. Results showed that radial, tangential, and longitudinal shrinkages of juvenile wood were significantly different from the corresponding shrinkages of mature wood. In addition, no significant difference was observed in shrinkage properties between partially CAD-deficient and wild-type loblolly pine. The third study dealt with development of a method for evaluating mechanical properties of small young trees in static bending and compression parallel to the grain utilizing the full cross section of the tree. In the absence of an established test method, the approach was to start from ASTM standard test of small clear wood. The experiment was designed as a replicated 5-level Graeco-Latin square with tree, stem location, dimensional ratio of the test specimen, and test strain rate as factors. Span-to-depth ratio for bending, length-to-diameter ratio for compression, and strain rates were established as test variables based on the analysis of the result. Along the tree height, there was no significant difference in mechanical properties starting from the base to 0.45 of the total height of the tree. en_US
dc.rights I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. en_US
dc.subject loblolly pine en_US
dc.subject partially-CAD deficient en_US
dc.subject Pinus taeda en_US
dc.subject bending test en_US
dc.subject wood mechanical properties en_US
dc.subject shrinkage en_US
dc.subject Graeco-Latin square design en_US
dc.subject compression test en_US
dc.title Evaluation of Wood Properties of Genetically Modified Trees en_US
dc.degree.name MS en_US
dc.degree.level thesis en_US
dc.degree.discipline Wood and Paper Science en_US

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