The heartwood of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) is known to be relatively resistant to attack by wood-destroying fungi. Previous investigations on other species has established various heartwood extractives as the primary deterrents to decay. Several extraneous fractions from Douglas fir were isolated and evaluated for fungicidal activity in order to determine the precise factor influencing the durability of this species. An acetone, ether and water extraction of Douglas fir heartwood meal provided five separate components, namely: a dihydroquercetin, free acid, neutral, phlobatannin and carbohydrate fraction. A bioassay of these materials was made using Fomes annosus (Fr.) Cke., Lentinus lepideus Fr. and Poria incrassata (B.&C.) Curt. as the test fungi. Both a cellulosic and a non-cellulosic substrate were employed. Small wood blocks from which certain extractives had been removed were used for the cellulosic substrates, whereas malt agar impregnated with varying concentrations of the extraneous materials represented the non-cellulosic media. The degree of effectiveness of each component as a fungicide was expressed numerically. Dihydroquercetin was found to be the most potent fungicide, completely inhibiting growth of the most sensitive fungus at a concentration of slightly less than 0.5 per cent. This value compares favorably with experimental results previously reported with phenolic extractives of the genus Pinus. On the basis of these data, timber selected for its high dihydroquercetin content could be expected to have an extended service life when used under conditions favoring decay. The possibility of breeding highly resistant genetic types is also discussed briefly. / Forestry, Faculty of / Graduate

This study examines the hypothesis that coniferous wood fibre origin is maintained even when purified pulps are subjected to severe mechanical (beating) and chemical (decrystallizing) treatments. Four to five intra-incremental sulphate pulps obtained from each of three species, eastern larch (Larix lariaina (Duroi) K. Koch), Douglas fir (Pseudotsuga menziessii (Mirb.) Franco) and balsam fir (Abies balsamea (L.) Mill), were purified and machined to one or three levels EL (170 ± 45 ml Csf), DF (615 + 90 ml Csf; 328 + 43 ml Csf; 168 ± 62 ml Csf) and BF (190 + 30 ml Csf). Thereafter, cellulose supermolecular structures were altered by monoethylamine swelling, with changes (48 ± 2% vs. 68 ± 2%) quantified as fibre crystallinity index measured by X-ray diffractometry. Paper sheet apparent densities and tensile parameters (maximum strength, "stretch," modulus of elasticity and rupture energy) were determined. Fibre surface areas and sheet bonded states were estimated by light scattering coefficient measurements. The effects of wood origin on paper sheet physical-mechanical properties reported by other researchers were reaffirmed in this study, with all factors decreasing progressively across growth increments. The differences of wood intra-incremental, as well as species origins, were not removed by conventional pulping and papermaking processes, or additional treatments such as severe beating or major alteration of the basic cellulose structures as practiced in the study. Paper sheet tensile properties were related directly to sheet apparent density. Correlation coefficients as high as 0.979 and 0.989 were obtained for 00% and 82% monoethylamine decrystallized fibre sheets, respectively. Sheet density was inversely related to wood specific gravity and was found to be independent of wood species, degree of beating and decrystallization treatments. It is shown that fibre bonding potential is not the only factor influencing paper sheet strength. Intrafibre characteristics, such as cellulose supermolecular structures, have a highly significant effect on paper sheet strength as well. In addition, specific energy of "bond failure" (irreversible energy consumed per unit sheet surface formed as result of tensile straining) was higher for earlywood than for latewood sheets. This energy quantity depends on beating degree and differs according to species, as well as intra-incremental origin. The paper sheet light scattering coefficient (L.S.C.)-density relationship also depended on wood fibre origin. Earlywood sheet L.S.C. decreased with increased beating and sheet density, but latewood sheet L.S.C. remained almost unaffected. This observation explains why whole-wood fibre sheet L.S.C.-density relationships vary with pulp types as recorded in the literature. / Forestry, Faculty of / Graduate

Lack of a selective holocellulose isolation procedure and the problem of limited material have long frustrated the attempts of wood scientists to accurately measure and describe carbohydrate yields within coniferous growth zones. A new method has been devised for micro-cellulose determination, Alpha-(formula omitted) cellulose yield maybe quantitatively estimated as the corrected yield of nitrated wood meal. Three - O.1 g wood meal samples provide a statistically reliable determination. A major limitation of the new technique, however, is that it cannot be applied to all woods. Sixty positions within ten increments representing five Canadian coniferous woods of different genera were examined and intra-incremental patterns were constructed. Anova and Duncan's test showed latewood (formula omitted) -cellulose yield to be greater than that of earlywood by a highly significant degree. Alpha-cellulose content throughout mature growth zones was estimated reliably by linear correlation or, more accurately, by logarithmic transformation used in a recent mathematical model. The successful application of the latter is its first reported use describing the non-linear behaviour of a wood chemical property across a coniferous increment. These patterns showed relationship of the long-chain carbohydrate fraction to seasonal development within coniferous growth zones. In addition, six of the ten patterns demonstrated new chemical evidence pertaining to a physiologically significant phenomenon in earlywood. Therein, minimum (formula omitted) -cellulose yield occurs at considerable cellular depth following cambial reactivation in the growing season. First-formed earlywood appears to retain some similarity at the chemical level of organization to last-formed tissues of the preceding season. Later-formed earlywood (i. e. , from the present year) does not appear to retain such similarity. From earlier work of this laboratory, lignification patterns were described for the same materials, using ultraviolet measurements on acetyl bromide-acetic acid digestion products of two wood meal samples. Examination of (formula omitted) -cellulose and lignification patterns provided evidence for their mutually exclusive behaviour. For the ten increments studied, the (formula omitted) -cellulose estimate (x̅ = 45.9 + 2.0%) was the exact complement of lignification (x̅ = 27. 4±1. 9%) at all positions but one. The linear regression for data from all increments was highly significant ( r = - 0.785). In addition, micro (formula omitted) -cellulose and micro lignin values, when combined, showed a definite tendency to cluster about a central value (x̅ = 73. 4 ± 1. 2%) suggesting that certain species require a common, critical measure of high molecular weight material. Dispersion about combined lignin and (formula omitted) -cellulose estimates was significantly less than about either of their individual means. This suggests much closer physiological control over the combination of these chemical entities, indicating that tree physiology is oriented more towards the finished bio synthetic product than towards the individual components involved in such a system. As a means of measuring successful nitrocellulose preparation, intrinsic viscosity (formula omitted) was used to indicate presence or absence of extensive degradation. Because of the highly variable at each position tested, no consistent trends in chain length were found across growth zones. However, in four increments, significant differences in (formula omitted) throughout the earlywood provided further evidence of two earlywood types. / Forestry, Faculty of / Graduate

Tensile and compression strength properties of six coniferous woods were studied at the tissue level. Relationships of these properties to specific gravity variations in three adjacent growth increments of each species were explored. Pacific yew was excluded from tensile strength analyses, since the material available did not lend itself to micro-tensile testing. The main purpose of the investigation was to examine, at the tissue level, in what manner specific gravity influences tension parallel and compression perpendicular to grain strengths. Wood strength—specific gravity relationships for gross wood based on earlier studied, were compared to tissue relationships. Distributions of specific gravity and stresses within growth increments of woods having gradual transition from earlywood to latewood, as represented by western white pine, and of woods having abrupt transition, as Douglas fir, were also compared. Feasibility of radial micro-compression test methods established previously for Douglas fir were re-examined and extended to all six species. Experimental material, from freshly felled trees was never dried before physical testing, except western red cedar. Specimens for tensile and compression tests were cut from each increment studied. Micro-specific gravity determinations, based on green volume and oven-dry weight, were performed on broken tensile test specimens after extraction with standard solvents. Physical tests were carried out by established techniques. Regression analysis was employed to establish equations and curves best describing relationships of maximum micro-tensile and micro-compression stresses to specific gravity. Test results revealed highly significant relationship between maximum micro-tensile stress and specific gravity, and between maximum micro-compression stress and specific gravity. The latter relationship is curvilinear, expressed by an exponential curve fitting five of the six species studied. Pacific yew, also significantly correlated to specific gravity at 95 per cent probability, was described by the same basic equation applied to the grouping of the other five woods, but with different constants. This suggests that specific gravity influences maximum micro-compression stress variations in species of greatly different physical and anatomical, characteristics in varying degrees. Comparing tensile and compression stress—specific gravity variations of gross wood with those of wood tissue, it was found that in both properties specific gravity caused greater stress increase of gross wood than of tissue, as illustrated by respective regression lines. No definite trend of specific micro-compression stress within growth increments was found. Specific micro-tensile stress distributions showed a peak-value close to or at the initiation of latewood. Specific gravity, maximum micro-tensile stress and maximum micro-compression stress in woods having gradual transition from earlywood to latewood vary gradually across the increment, suggesting trends of a second degree parabola. In woods where transition is abrupt, the increase of these properties is abrupt at or close to the initiation of latewood. If in such woods the latewood zone is wide the distribution curve is sigmoid. Methods for testing wood tissue in radial compression, as well as theories related to the analysis of stress-deformation curves, have been verified. Ultimate load is recorded at the inflection point on the curve, beyond the proportional limit. At this phase of compression ultimate compressibility of the tracheids is achieved. / Forestry, Faculty of / Graduate

The Honourable Mr. Ralph Loffmark, British Columbia's Minister of Trade and Commerce, has taken the position that demand for woodpulp will greatly exceed the supply during the next five years. On the other hand, leaders of British Columbia's pulp and paper industry fear that a large surplus of pulp is inevitable. In this thesis, the difference of opinion was examined by forecasting demand for paper and paperboard for the period of 1965 to 1975. From this estimate was derived the expected requirements for chemical pulp and bleached sulphate market pulp for the same period. The demand for bleached sulphate was then compared with the potential supply, leading to the judgement that a surplus condition will exist. Finally, the principal factors which would affect the financial outcome for an independent bleached sulphate pulp mill were analyzed. The conclusion was reached that an independent firm would be profitable in spite of the anticipated surplus. / Business, Sauder School of / Graduate

Because of an interaction between the load history and the material's properties a reduction in the serviceability of safety of a structure may be seen as the result of a random process of damage accumulation with time. A damage model is proposed and verified to deal with this type of problem in general, and specifically with duration-of-load effects in timber structures. Through comparisons with and discussion of other damage accumulation models, the proposed model is found to be both suitable to represent experimental results and relatively easy to use. A reliability analysis for a single structural member with a service life of 30 years is studied for different snow loading conditions of three Canadian cities,using the damage model in combination with Rackwitz-Fissler's algorithm. A simplified analysis method is proposed and compared with a large-scale Monte-Carlo simulation. The results of the reliability analysis are found to be satisfactory. Finally, the implementation of the reliability analysis in a simple design guideline for load duration effects is discussed. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Thujaplicins are the major components in the steam-volatile fraction of western redcedar (Thuja plicata Donn.) (WRC) heartwood extractives. They are consided to be highly toxic to fungi and are chiefly responsible for WRC heartwood decay resistance. This study proves that this traditional concept of toxicity is not completely correct. Thujaplicins are toxic to common decay fungi isolated from decayed WRC wood in living trees or wood in service, such as Poria albipelIucida Baxter. On the other hand, when a fungus such as Sporothrix sp. invades sound heartwood of living WRC, thujaplicins do not provide resistance but instead are altered by that fungus, so that their toxicity to decay fungi is destroyed. Evidence obtained in this study indicates that the mechanism of thujaplicin toxicity to common decay fungi involves the reactive keto-enolic group. As example, thujaplicin toxicity disappears if this reactive group is blocked by laboratory methylation. In living trees detoxification by Sporothrix sp. is demonstrated to involve a process of oxidative dimerization and isomerization of the thujaplicins to a new lactone compound. This compound is proven to have no toxicity to decay fungi, such as Poria albipelIucida Baxter. The dimerization and isomerization destroy the reactivity of the keto-enolic group and thus thujaplicin toxicity. Isolation, purification, and determination of the chemical structure of the new lactone compound produced from thujaplicins during Sporothrix sp. infection was carried out by chemical, chromatographic and spectroscopic methods. This naturally occurring compound has not been isolated previously and there are no previous reports in the literature about a compound with this structure. Following IUPAC rules, the compound is named as 3,3,4,7,7,8-hexamethyl-2,6-dioxa-1,5-anthracene-dione, and given the trivial name 'Thujin'. Biological experiments carried out in this study clearly show that in living WRC trees, fungal attack involves a succession of microorganisms. Three early stage attacking fungi were consistantly isolated from discolored WRC heartwood. They are identified as Sporothrix sp. KirschsteinieIIa thujina (Peck) Pomerleau & Etheridge and Phialophora sp. Biological roles of these fungi are demonstrated based upon the results of wood block bioassays and chemical analysis of wood blocks treated with the three fungal isolates. / Forestry, Faculty of / Graduate

Foam separation has been successfully developed on a 4-1 laboratory column, an 80-1 field column installation and a 6000 gal pilot plant trough type system as a novel process for detoxifying bleached kraft mill effluents. Toxic surface active materials such as resin and unsaturated fatty acids collect at the gas-liquid interface of rising air bubbles and concentrate in the foam. The highly toxic collapsed foam represents 1-2% by volume of the influent and is subsequently detoxified by biological treatment. Process parameters controlling detoxification efficiency are pH, gas-liquid interfacial area, initial toxicity level and mode of operation. The gas-liquid interfacial area and pH are of utmost importance. For a typical effluent with MST of 3-4 hr, approximately 20-2 30 m²/l of interfacial area given to an effluent at pH > 7.0 are required for detoxification. Foam separation is universally applicable and reliable for detoxifying kraft whole mill effluent. Over 80% of 205 samples from 10 Canadian mills were detoxified. A 1 gal/min, one and two stage continuous flow systems detoxified over 90% of samples at pH 8 and 1-2 hr retention time over 80 days of operation period. Study of detoxification mechanism indicated that foam fractionation accounts for 77.5% of detoxification, volatization for 5.4% and unidentified mechanisms for 17.1%. Depending on the mode of operation, up to 5% of effluent volume was discharged as foam. The foam volume could be reduced to < 2% by increasing foam retention time and enhancing internal reflux. Collapsed foam was readily detoxified by a biodisc or aerated lagoon process. In addition to detoxification, foam separation removed 20-60% of suspended solids, 66% resin acids, 12% B0D5 (10% TOC), 8% color and 80% foaming tendency. Suspended solids removal could be increased to 88% if an expensive dissolved air system were used for bubble generation. Commercially available equipment for foam generation and foam breaking was reviewed. Jet aerators and turbine systems were assessed as most suitable for commercial application. Pilot plant evaluation of this equipment indicated that reliable and consistent operation could be obtained. The results were used to establish empirical formulae for use in process scale up. During a 4 month continuous flow study, approximately 5-7 m²/l of gas-liquid interfacial area was provided to detoxify 80-100 gal/min of mill A effluent with MST of 6-10 hr. The detoxification success rate of a large number of samples increased from 50 to 86 and to 100% as the operation changed from 1 to 2 to 3 stages. The foam produced by the pilot plant was collapsed by a 12" diameter turbine at 100% efficiency all the time. Costs of foam separation were examined for a projected 3 stage foam separation process, treating 25 M gal/day of bleached kraft whole mill effluent. Capital costs for pH control, foam generation, foam breaking and foam treatment were estimated at $2.26 M. Operating costs were estimated at $2.35/ton of pulp. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

It has been indicated through a review of the literature that wood by-products have a potential as a dietary source of energy for the ruminant animal. However, lignin constitutes a barrier to the proper utilization of cellulose. Generally, any treatment to remove or alter lignin makes the cellulose within lignocellulose materials more susceptible to the activity of the cellulolytic enzymes. Therefore, an efficient biological treatment would require a system to solubilize or to remove lignin from the lignin-carbohydrate complex. Cellulose within ruminant feeds forms an effective substrate for eventual conversion to body protein. There are several methods available for delignification. This study was carried out using the thermophilic aerobic oxidation method for which swine manure was used both as the source inocula and initial culture media. In the process of degradation, a part of the energy produced was utilized by the bacteria for cell function and multiplication. The remainder of the available energy was released as heat energy. In this method the heat necessary to maintain the temperature in the thermophilic range was derived from both mechanical and from microbial activity. Thermophilic activity is considered to reduce the time required for organic waste digestion over that experienced by mesophilic digestion. The rate of the destruction of pathogenic bacteria, virus and other organisms is increased as a result of the high temperatures fermentation. Batch studies conducted to delignify alder sawdust by the use of the aerobic thermophilic oxidation method demonstrated that the lignin content of sawdust can be reduced by as much as 74%, and crude bacterial protein was generated by approximately 17%. Constant supply of small amounts of swine manure ensures high temperature maintenance. Periodical addition of 2 kg sawdust within thermophilic temperature range results in better delignification. / Land and Food Systems, Faculty of / Graduate

The work presented in this thesis is divided into four chapters. Chapter I describes the control of the crystallization behavior of syndiotactic polystyrene (sPS) by chemical modification of sPS using sulfonation. In Chapter II, preparation of wood-ceramic composites through sol-gel processes is described. Chapter III describes the end-functionalization of poly(ethylene oxide)s (PEOs), and the interfacial properties of the functionalized PEOs. Finally, the distribution of chain conformation of PEO in the liquid state is discussed in Chapter IV. Direct sulfonation of highly stereoregular syndiotactic polystyrene (sPS) has been accomplished in chloroform. The degree of sulfonation can be effectively controlled. The crystallization behavior of sulfonated sPS is considerably different than the unmodified polymer. The crystallinity and the crystallization kinetics of sPS decrease with increasing extent of modification. Wood-ceramic composites were prepared by introducing a ceramic component into pine, a softwood, through sol-gel processes. Several ceramic precursors, including SiCl$\sb4$, Si(OCH$\sb3)\sb4$, and CH$\sb3$SiCl$\sb3$, were used. The ceramic content introduced into the wood structure can be controlled by varying the reaction time and the moisture content of wood. The modification of wood by CH$\sb3$SiCl$\sb3$ in supercritical CO$\sb2$ penetrated the entire wood structure, generating a macroscopically uniform distribution of the ceramic component in wood. Samples with one or both ends of monodisperse PEO functionalized with perfluorodecanoyl groups (PEO$\sp{\rm F}$ or PEO$\sp{\rm F2}$) were synthesized and blends of these end-capped PEOs with PEOs of the same molecular weight (M$\sb{\rm n}$$\sim$2000 - $\sim$16000) were prepared as cast films. Due to the lower surface energy of the fluorocarbon end groups, the modified PEOs preferentially adsorb to the free polymer surface. The surface concentration of the perfluoroalkyl end groups was measured by XPS which indicates that perfluoroalkyl chain ends adsorb to the polymer surface in a reasonably close-packed fashion (at all molecular weights) and leave a zone depleted of fluorine immediately beneath the highly fluorinated surface region. There is only a slight effect of molecular weight on surface fluorine content indicating a "stretched brush" conformation for the higher molecular weight samples. The adsorption of these polymers at the air-water interface was studied as well. The packing density and the orientation angle of the fluorinated chain end segregated at the interface were assessed by external reflectance IR. Isotropic Raman spectra of PEO in aqueous solution and in the melt were simulated by superposing calculated spectra resulting from a series of normal coordinate calculations performed for an ensemble of conformers, and compared with the corresponding experimental results. The conformational distribution for poly(ethylene oxide) in the molten state favors the tgg' conformer, and the aqueous solution of poly(ethylene oxide) contains mostly tgt conformers. The results for PEO were supported by measurements and computations made using 1,2-dimethoxyethane as a model.