Log breakdown by sawing can be viewed as a multi-phase process that converts logs into boards by a series of cutting operations. In the primary phase, logs are sawn into s labs of wood known as flitches or cants. These are further processed by secondary operations, that resaw, edge (cut lengthwise) and trim (cut widthwise) the raw material, resulting in the manufacture of the board product whose value is influenced by its composite dimensions and quality (as indicated by a grade). Board grade is in turn determined by the number, type, size, and location of defects. Owing to its biological origins, each log, and subsequent board, is unique. Furthermore, as each sawmill, and processing centre within the mill, has a unique configuration, the problem of determining how each log entering a mill should be sawn is very complex. Effective computer simulation of log breakdown processes must therefore entail detailed descriptions of both geometry and quality of individual logs. Appropriate strategies at each breakdown phase are also required. In this thesis models for emulating log breakdown are developed in conjunction with an existing sawing simulation system which requires, as input, detailed three-dimensional descriptions of both internal and external log characteristics. Models based on heuristic and enumerative procedures, and those based upon the principles of dynamic programming (DP) are formulated, encoded, and compared. Log breakdown phases are considered both independently and in a combined integrated approach-working backwards from the board product through to the primary log breakdown phase. This approach permits methodology developed for the later processes to be embedded within the primary phase thus permitting the determination of a global rather than local solution to the log breakdown problem whose objective is to seek the highest possible solution quality within the minimum possible time. Simulation results indicate that solution quality and processing speeds are influenced by both solution methodology and degree of data complexity. When the structure of either factor is simplified, solutions are generated more rapidly-but with an accompanying reduction in solution quality. A promising compromise that combines DP techniques with mathematical functions based on a subset of the original data is presented. / Subscription resource available via Digital Dissertations only.

Log breakdown by sawing can be viewed as a multi-phase process that converts logs into boards by a series of cutting operations. In the primary phase, logs are sawn into s labs of wood known as flitches or cants. These are further processed by secondary operations, that resaw, edge (cut lengthwise) and trim (cut widthwise) the raw material, resulting in the manufacture of the board product whose value is influenced by its composite dimensions and quality (as indicated by a grade). Board grade is in turn determined by the number, type, size, and location of defects. Owing to its biological origins, each log, and subsequent board, is unique. Furthermore, as each sawmill, and processing centre within the mill, has a unique configuration, the problem of determining how each log entering a mill should be sawn is very complex. Effective computer simulation of log breakdown processes must therefore entail detailed descriptions of both geometry and quality of individual logs. Appropriate strategies at each breakdown phase are also required. In this thesis models for emulating log breakdown are developed in conjunction with an existing sawing simulation system which requires, as input, detailed three-dimensional descriptions of both internal and external log characteristics. Models based on heuristic and enumerative procedures, and those based upon the principles of dynamic programming (DP) are formulated, encoded, and compared. Log breakdown phases are considered both independently and in a combined integrated approach-working backwards from the board product through to the primary log breakdown phase. This approach permits methodology developed for the later processes to be embedded within the primary phase thus permitting the determination of a global rather than local solution to the log breakdown problem whose objective is to seek the highest possible solution quality within the minimum possible time. Simulation results indicate that solution quality and processing speeds are influenced by both solution methodology and degree of data complexity. When the structure of either factor is simplified, solutions are generated more rapidly-but with an accompanying reduction in solution quality. A promising compromise that combines DP techniques with mathematical functions based on a subset of the original data is presented. / Subscription resource available via Digital Dissertations only.

Log breakdown by sawing can be viewed as a multi-phase process that converts logs into boards by a series of cutting operations. In the primary phase, logs are sawn into s labs of wood known as flitches or cants. These are further processed by secondary operations, that resaw, edge (cut lengthwise) and trim (cut widthwise) the raw material, resulting in the manufacture of the board product whose value is influenced by its composite dimensions and quality (as indicated by a grade). Board grade is in turn determined by the number, type, size, and location of defects. Owing to its biological origins, each log, and subsequent board, is unique. Furthermore, as each sawmill, and processing centre within the mill, has a unique configuration, the problem of determining how each log entering a mill should be sawn is very complex. Effective computer simulation of log breakdown processes must therefore entail detailed descriptions of both geometry and quality of individual logs. Appropriate strategies at each breakdown phase are also required. In this thesis models for emulating log breakdown are developed in conjunction with an existing sawing simulation system which requires, as input, detailed three-dimensional descriptions of both internal and external log characteristics. Models based on heuristic and enumerative procedures, and those based upon the principles of dynamic programming (DP) are formulated, encoded, and compared. Log breakdown phases are considered both independently and in a combined integrated approach-working backwards from the board product through to the primary log breakdown phase. This approach permits methodology developed for the later processes to be embedded within the primary phase thus permitting the determination of a global rather than local solution to the log breakdown problem whose objective is to seek the highest possible solution quality within the minimum possible time. Simulation results indicate that solution quality and processing speeds are influenced by both solution methodology and degree of data complexity. When the structure of either factor is simplified, solutions are generated more rapidly-but with an accompanying reduction in solution quality. A promising compromise that combines DP techniques with mathematical functions based on a subset of the original data is presented. / Subscription resource available via Digital Dissertations only.

Log breakdown by sawing can be viewed as a multi-phase process that converts logs into boards by a series of cutting operations. In the primary phase, logs are sawn into s labs of wood known as flitches or cants. These are further processed by secondary operations, that resaw, edge (cut lengthwise) and trim (cut widthwise) the raw material, resulting in the manufacture of the board product whose value is influenced by its composite dimensions and quality (as indicated by a grade). Board grade is in turn determined by the number, type, size, and location of defects. Owing to its biological origins, each log, and subsequent board, is unique. Furthermore, as each sawmill, and processing centre within the mill, has a unique configuration, the problem of determining how each log entering a mill should be sawn is very complex. Effective computer simulation of log breakdown processes must therefore entail detailed descriptions of both geometry and quality of individual logs. Appropriate strategies at each breakdown phase are also required. In this thesis models for emulating log breakdown are developed in conjunction with an existing sawing simulation system which requires, as input, detailed three-dimensional descriptions of both internal and external log characteristics. Models based on heuristic and enumerative procedures, and those based upon the principles of dynamic programming (DP) are formulated, encoded, and compared. Log breakdown phases are considered both independently and in a combined integrated approach-working backwards from the board product through to the primary log breakdown phase. This approach permits methodology developed for the later processes to be embedded within the primary phase thus permitting the determination of a global rather than local solution to the log breakdown problem whose objective is to seek the highest possible solution quality within the minimum possible time. Simulation results indicate that solution quality and processing speeds are influenced by both solution methodology and degree of data complexity. When the structure of either factor is simplified, solutions are generated more rapidly-but with an accompanying reduction in solution quality. A promising compromise that combines DP techniques with mathematical functions based on a subset of the original data is presented. / Subscription resource available via Digital Dissertations only.

The use of fossil derived products and the environmental and economic problems associated with them have made a shift to abundant renewable resources such as forest biomass more attractive. However before forest biomass can be used as a resource, its properties must be known. This study determined the physical properties of heterogeneous biomass residues produced during harvesting on two operational forest sites within the Great Lakes-St Lawrence forest of south-eastern Ontario. Properties measured were moisture content, size distribution, bulk density, and wood-to-bark ratio; also thermo-chemical properties including elemental composition, thermal reactivity and energy content were measured. The effects of forest site and harvest type, storage and position in storage pile, on the properties of biomass were also investigated. Results of the study showed that the various heterogeneous forest harvest residues differed more physically than thermo-chemically for the different variables, and this affected biomass procurement more than the potential utilization options.

The use of fossil derived products and the environmental and economic problems associated with them have made a shift to abundant renewable resources such as forest biomass more attractive. However before forest biomass can be used as a resource, its properties must be known. This study determined the physical properties of heterogeneous biomass residues produced during harvesting on two operational forest sites within the Great Lakes-St Lawrence forest of south-eastern Ontario. Properties measured were moisture content, size distribution, bulk density, and wood-to-bark ratio; also thermo-chemical properties including elemental composition, thermal reactivity and energy content were measured. The effects of forest site and harvest type, storage and position in storage pile, on the properties of biomass were also investigated. Results of the study showed that the various heterogeneous forest harvest residues differed more physically than thermo-chemically for the different variables, and this affected biomass procurement more than the potential utilization options.

Master of Science / Apparel, Textiles, and Interior Design / Sherry J. Haar / This study compared the colorfastness of potassium aluminum sulfate (PAS) mordanted and nonmordanted 30/2 wool yarn, dyed with black walnut (Juglans Nigra), Osage orange (Maclura pomifera), and eastern redcedar (Juniperus virginiana) sawdust. Information from this study is intended to inform natural dye artisans and to increase the profitability of sawdust for farmers, ranchers, and mill owners who would otherwise find little use for this byproduct of timber manufacturing. Pre-testing ensured dyeings of visually comparable color depth and dye concentrations were pre-tested to find a standard depth of shade between the same dye on PAS mordanted and nonmordanted wool yarns. Tests for colorfastness to light, laundering and staining were performed in accordance to AATCC test methods. Resulting colors for exposed and unexposed specimens were rated using CIE L* a* b* values and AATCC gray scale for color change. GLM Anovas and two-sample t-tests were used to statistically analyze CIE L* a* b* values. As expected, findings indicated that dye absorption was improved with the use of a PAS mordant, especially for black walnut and eastern redcedar. For yarns premordanted with PAS the dyewoods became yellower. A PAS mordant slightly improved colorfastness to light for black walnut and eastern redcedar, but did not influence Osage orange which had an unexpected color change from bright yellow to warm brown after exposure to light. Colorfastness to laundering was slightly improved with PAS for Osage orange, while black walnut and eastern red cedar had slightly less color change without the mordant. This research was supported by the Agricultural Research Experiment Station and Kansas State University.

Mechanisms of adsorption of alkaline copper quat (ACQ) components in wood were investigated with emphasis on: copper chemisorption, copper physisorption, and quat adsorption. Various factors were investigated that could affect the adsorption of individual ACQ components in red pine wood. Copper chemisorption in wood was affected by ligand types coordinating with Cu and the stability of the Cu-ligand complexes in solution. For Cu-monoethanolamine (Cu-Mea) system, the prevailing active solvent species at the solution pH, [Cu(Mea)2-H]+ complexes with wood acid sites and loses one Mea molecule through a ligand exchange reaction. The amount of adsorbed Cu was closely related to the cation exchange capacity of wood. An increase in Mea/Cu ratio increased the proportion of the uncharged Cu-Mea complex and resulted in decreased Cu chemisorption in wood. Copper precipitation is also an important Cu fixation mechanisms of Cu-amine treated wood. X-ray diffraction analysis revealed that in vitro precipitated Cu was a mixture of copper carbonates (azurite and malachite) and possibly Cu2O. Higher concentration Cu-amine solutions retarded the Cu precipitation to a lower pH because of higher free amine in the preservative-wood system. The changes in zeta potential of wood in relationship to the quaternary ammonium (alkyldimethylbenzylammonium chloride: ADBAC) adsorption isotherm showed two different adsorption mechanisms for quat in wood: ion exchange reaction at low concentration and additional aggregation form of adsorption by hydrophobic interaction at high concentration. Because of the aggregation effect, when wood was treated with ACQ, high amounts of ADBAC were concentrated near the surface creating a steep gradient with depth. This aggregated ADBAC was easily leached out while the ion exchanged ADBAC had high leaching resistance. Free Mea and Cu of ACQ components appeared to compete with ADBAC for the same bonding sites in wood.

The effects of ACQ solution parameters such as copper to quat ratio, pH and copper to ligand ratio on distribution of copper complexes in solution and insoluble precipitates, and on fixation and leaching of copper in treated wood were evaluated. The distribution of ionic complexes, predicted by equilibrium speciation model (MINTEQA2), was related to laboratory fixation and leaching results at controlled ACQ solution parameters. A decrease in the relative proportion of copper in the ACQ formulation from a copper oxide (CuO) to didecyldimethylammonium carbonate (DDACb) ratio of 2:1 to 1:1 and 1:2 resulted in lower copper retention in the treated samples and substantially decreased the amount of copper leached per unit area. For monoethanolamine (Mea) based ACQ, solution parameters which favour a higher proportion of monovalent cationic complex, which consume one reactive site in wood, and the presence of insoluble carbonate precipitate of copper in wood during preservative treatment resulted in higher leach resistance compared to the neutral copper complex present at higher pH. Ammonia (NH3) based ACQ can fix more copper at high pH as there is no chelated neutral complex as in Mea based ACQ; however divalent copper-NH3 complexes may consume two sites to fix in wood. Addition of NH3 in Mea based ACQ at Cu:Mea:NH3 ratio of 1:4:6 at pH 10.6 significantly reduced copper leaching compared to 1:4:0 (without ammonia) at pH 9 due to increased divalent copper-ammonia complexes and decreased neutral copper amine complex at elevated pH. Ammonia addition with a lower proportion of Mea (1:2.5:4 at pH 10.5-10.7), significantly reduced copper leaching compared to 1:4:0 at pH 9; no reduction was observed for ammonia addition in ACQ with a higher proportion of Mea (1:4:4 at pH 10.45). The lower copper leaching from 1:2.5:4 resulted from the higher amount of divalent copper-NH3 complexes at higher pH without compromising the amount of copper precipitated at lower pH. The higher percent copper leached from tetramethylethylenediamine (Tmed) based ACQ compared to Mea and NH3 based ACQ suggested that highly stable complexes tend to stay in solution and do not result in leach resistant copper in the wood.

A number of fungi produce spalted wood, which is characterized by accumulation of black pigment in fine demarcation lines, often accompanied by discoloration or staining on the wood fibers. Specific spalting fungi were identified by molecular analysis. From a total of 19 isolates and 140 clones studied, 11 fungal species were identified. The two Chlorociboria species from North America were investigated and their anamorphs were unambiguously identified for the first time. Fungal pigment formation under the influence of moisture content and pH variation was investigated in sugar maple, American beech and agar inoculated with spalting fungi. Maximum pigment production occurred at treatment with pH 4.5 for sugar maple and beech inoculated with Trametes versicolor. Xylaria polymorpha produced external pigmentation in beech treated with buffer at pH 5 and sugar maple at pH 4.5. Fungal pigmentation by Trametes versicolor and Xylaria polymorpha was stimulated at low moisture content in both wood species tested. Melanin production by Inonotus hispidus and Polyporus squamosus was stimulated above 22-28% and 34-38% moisture content in beech and in sugar maple respectively. Fomes fomentarius and Polyporus brumalis produced maximum pigmentation in beech at 26 - 41% and in sugar maple at 59 - 96% moisture content. The variation of the moisture content and pH values of wood substrates can stimulate the intensity of pigmentation of specific fungi in wood. To investigate melanin synthesis from a variety of melanin precursors, experimental research on three spalting fungi tested their reaction to catechol and L-Dopa melanin precursors in wood and agar substrate. The results indicate multiple biosynthesis pathways for melanin assembly in Trametes versicolor, Xylaria polymorha and Inonotus hispidus, and catechol produced most pigmentation in all spalting fungi investigated. Microscopic analysis by light, fluorescence, electron and confocal microscopy also indicates a bi- or multi-modal activity of melanin production and assembly by several spalting fungi. Possible variations of melanin assembly were identified based on fungal and wood species. Immunofluorescence and immunogold labelling with Mab 6D2 melanin antibody confirmed the melanin nature of the pigments produced by Oxyporus populinus, Trametes versicolor, Xylaria polymorpha, Fomes fomentarius, and Inonotus hispidus.