[Part I] Desoxytigogenin was prepared by oxidation followed by Wolff-Kishner reduction of tigogenin. A number of methods were employed to open the side chain of desoxytigogenin to the corresponding dihydrodesoxytigogenin. Oxidation of dihydrodes-oxytigogenin yielded the corresponding C₂₆ aldehyde, which was isolated in pure form and characterised unambiguously. Bromination studies under varying conditions have been made on this aldehyde but the results have not been completed as yet. [Part II] The ground material from the bark of Diphlorynchus Mossambicensis was extracted with methanol, and methanol soluble concentrate was obtained. In addition a green gummy material, sparingly soluble in methanol, was obtained. The methanol concentrate was separated into acid, basic and neutral fractions and preliminary chemical investigations were made on these fractions. Two crystalline substances of empirical formulas C₃₀₋₃₅H₄₄₋₅₄O₂ and C₃₇₋₃₈H₅₂₋₅₆O₂ have been isolated, separated and purified from the green gummy material. Spectral and analytical data have been collected and a few chemical reactions have been made on these two compounds. / Science, Faculty of / Chemistry, Department of / Graduate

Because of difficulty experienced with visual observation of bleached, unstained softwood tracheids, a study was initiated to determine the best microscopic system, for observation of this type of material. A comparison was made between bright-field, dark-field, polarising, phase, electron, fluorescence and interference microscopic systems. In addition, the optical characteristics of each type of microscope were studied to determine the reasons for the differences in visual results. The study was expanded to include an evaluation of the interference microscope and its use in measuring refractive index of bleached wood pulp. The interference microscope was found to give visual images superior to those obtained with any of the other systems examined and thus constitutes an important, contribution to the practice of microscopy. Inconclusive results were obtained in the evaluation of the system of measurement of refractive index by means of the interference microscope. / Forestry, Faculty of / Graduate

A method is described for the preparation of an induced xylanase from Chaetomlum globosum. This soil micro-organism was first grown in synthetic liquid media containing xylan as the sole carbon source. After incubation at room temperature for a suitable time, the mycella were harvested, centrifuged and exposed to high frequency vibrations which ruptured the cell walls. The resulting clear enzyme solution was shown to be capable of hydrolysing xylan from wheat straw. The main end product of hydrolysis detected by means of paper chromatography was xylose. The action of this induced enzyme preparation on wood cellulose was studied. A considerable fraction of the xylan was removed without significantly changing the mannose or glucose content. In connection with the enzyme studies, a method is given for the quantitative determination of polysaccharides in wood-cellulose preparations. Direct photometric analyses of the wood hydrolysate spots on paper chromatograms were made with an adapted Beckman spectrophotometer. An analysis of selected commercial pulps is given together with a comparison of the method with conventional pentosan analyses. / Medicine, Faculty of / Biochemistry and Molecular Biology, Department of / Graduate

The hemicellulose isolated from apple wood (var. Golden Transparent) by alkaline extraction has been shown to contain a 4-0-methylglucuronoxylan. Hydrolysis of the hemicellulose yielded neutral sugars and uronic acids. Paper chromatographic examination of the neutral sugars showed D-xylose to be the major component with small amounts of other sugars corresponding to rhamnose, arabinose and galactose also being present. Two other sugars with Rf values greater than that of xylose were found but the identity of these components has not been established. An aldobiouronic acid was isolated and characterized as the crystalline acetate of 2-0-(4-0-methyl-⍺-D-glucopyranosyluronic acid)-D-xylose. In order to determine the mode of union of the component sugars the polysaccharide was methylated and then hydrolyzed to give 2,3,4-tri-O-methyl-D-xylose, 2,3 di-O-methy1-D-xylose, 2-0-(2,3-di-O-methyl-D-xylopyranosyl)-2,3-di-O-methyl-D-xylose, a dimethylated lyxose, 2-0- and 3-0-methyl-D-xylose, 2-0-(2,3,4-tri-O-methyl-D-glucopyranosyluronic acid)-D-xylose, and probably a trimethylated rhamnose. (The dimethylated lyxose isolated is not an integral constituent of the native polysaccharide since no lyxose was obtained in the acid hydrolyzate. It is thought to arise by epimerization of 2,3-di-0-methyl-D-xylose.) Quantitative analysis of the methylated hemicellulose has shown the tri-, di- and monomethyl pentose and 2,3,4-tri-O-methyl-D- ⍺- glucuronic acid to be present in the mole ratios of 1:97:21:19, respectively. The methyl ester of the methylated aldobiouronic acid was reduced with lithium aluminum hydride and the resulting neutral disaccharide hydrolyzed. The cleavage products were identified as 3-0-methyl-D-xylose and 2,3,4-tri-0-methyl -D-glucose indicating the uronic acid portion of the molecule to be linked through its reducing end to position 2 of a xylose moiety. Results obtained in this work show that the carbohydrate polymer isolated from apple wood consists of a backbone of approximately 119 anhydro-D-xylopyranose linked by 1,4-β-glycosidic bonds. The side chains are composed of single units of 4-0-methyl-D-glucuronic acid which occur at every sixth xylose residue. A rhamnose unit may perhaps be present as a side chain too, although it is not known whether this sugar is an integral constituent of the glucuronoxylan. The general features of the hemicellulose are very similar to glucuronoxylans isolated from other hardwoods and especially resemble white elm and cherry wood in its structure and high uronic acid content. We are grateful to Dr. C. T. Bishop who presented this work at the 43rd conference of The Chemical Institute of Canada, Ottawa, June I960. / Science, Faculty of / Chemistry, Department of / Graduate

The extractive free cherrywood on alkaline extraction gave, in 22.4 per cent yield, a hemicellulose composed of 106-ll4, 1-4 linked β-D-xylopyranose residues with side chains of 4-0--methyl-D-glucuronic acid attached to position 2 of every 7th anhydroxylose. The hemicellulose on hydrolysis yielded a neutral sugar, D-xylose, with traces of D-glucose and rhamnose. D-Xylose was characterized as the crystalline sugar, D-glucose was characterized as its p-nitroanilide, and rhamnose was characterized by electrophoresis and chromatography. An aldobiouronic acid was isolated from the acidic fragments and shown to be 2-0-(4-0-methyl-⍺-D-glucopyranosyluronic acid)-D-xylose by preparation of the crystalline acetate, methyl 2-0-[methyl (2,3-di-0-acetyl-4-0-methyl-⍺-D-glucopyranosyl) uronate ]-3,4-di-0-acetyl-D-xylopyranoside. The hemicellulose was methylated and the product fractionated to give three main fractions which were essentially homogeneous. Hydrolysis of one of the fractions yielded 2,3,4-tri-0-methyl-D-xylose (l mole) characterized by chromatography 2,3-di-0-methyl-D-xylose characterized as the crystalline sugar and anilide, and 2,3-di-0-methyl-D-lyxose characterized as the crystalline sugar and anilide (88 moles); and 2-0 and 3-0-methyl-D-xylose (l mole) characterized by electrophoresis. Traces of two disaccharides and an unknown monosaccharide were also found. A partially methylated aldobiouronic acid, 3-0-methyl-2-0- (2,3,4-tri-0-methyl-⍺-D-glucopyranosyluronic acid)-D-xylopyranose (l6 moles), was isolated and characterized as follows. The methyl ester methyl glycoside was prepared and then reduced to the disaccharlde. The disaccharide was hydrolysed to give 3-0-methyl-D-xylose and 2,3,-tri-0-methyl-D-glucose characterized as their crystalline anilides. Cherrywood hemicellulose resembles other glucuronoxylans isolated from hardwoods such as sugar maple and white birch but there is a higher uronic acid to xylose ratio than is usual for hardwood xylans. It resembles the xylan from white elm more closely in this respect. Recently apple-wood hemicellulose was isolated and shown to be similar to cherrywood hemicellulose. / Science, Faculty of / Chemistry, Department of / Graduate

The results of two hundred and fifty-eight static bending tests on young Douglas fir were obtained from the Vancouver Laboratory of the Forest Products Laboratories of Canada. Twenty-two trees had been sampled; seven of approximately sixty years of age from Port Moody, eight of about seventy years of age from Coombs (on Vancouver Island), and seven of approximately ninety years of age from Stave Lake. Stand site quality in each locality was similar and above average for second-growth fir from the coastal region of British Columbia. The laboratory's results were separated into two classes. Ninety-seven tests represented wood formed within the first five inches of radial growth in the tree. The remaining one hundred and sixty-one tests typified the older wood lying between the inner zone and the bark. Analyses of variance revealed highly significant differences in properties between zones. Wood from the inner zone had a faster growth rate, lower density (though wider bands of summerwood) and less strength and less stiffness in bending than wood from the outer zone. The influence of ring width, summerwood width and specific gravity on the moduli of elasticity and rupture was assessed for each zone by regression analyses. Ring width and summerwood width accounted for a significant amount of variation in modulus of elasticity and modulus of rupture in the two zones. Their influence on both moduli, however, was completely due to their association with specific gravity. Specific gravity, alone, accounted for almost twice as much of the variation in elasticity and bending strength as did ring width and summerwood width combined. The presence of compression wood in a few specimens from the outer growth zone weakened the relationship between modulus of elasticity and specific gravity in this zone but had no effect on the modulus of rupture — specific gravity relationship. In consequence, the influence of growth zone on modulus of elasticity could not be determined. The difference in average values of specific gravity between zones did not fully explain the similar difference between zones for average modulus of rupture values; an indication that radial growth zone in the tree had some influence on the bending strength independent to that exerted by density. / Forestry, Faculty of / Graduate

A high extractive-content temperate conifer wood (Pinus elliottii) was examined as a pulpwood source by organosolv pulping. Particularly, the behavior of the resin- and fatty acids during the lignin solvolysis process was studied in detail. For this purpose the resin-and fatty acids were characterized in the wood, and after pulping trials in order to reveal their fate during pulping, using catalyzed 80% aqueous alcohol (methanol) as solvent. Wood extractives were removed by both methanolic cold maceration and Soxhlet extraction techniques. The resin-and fatty acid fractions thus collected were saponified and/or methylated and characterized by gas liquid chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). No significant differences were found in regard to extraction efficiencies between the two types of cold extractions. Furthermore, there was no significant difference between these two types of cold extractions in comparison with the procedure described by TAPPI standard T 204 os-76. Pulping experiments were performed at 205°C for periods of 5, 20, 40, and 60 min. Lignins, which precipitated on cooling of the black liquor (Lignin fraction I), were set aside for further extractions and chemical analyses. The molecular weight distribution of these lignins was determined by size exclusion chromatography on an HPLC and their quantity was determined either gravimetrically or volumetrically. Precipitated Lignin Fraction I, suspected of containing some adsorbed extractives and some fiber fragments, was transferred to a tared crucible. The lignin and extractives were sequentially dissolved by using tetrahydrofuran (THF), acetone and methanol. This solution was evaporated, the residue redissolved in methanol-water (80:20) and the solution liquid-liquid extracted with diethyl ether in a separatory funnel followed by methylation prior to GC and GC-MS analysis. Quantification of the resin- and fatty acids in the wood and those recovered after organosolv pulping was performed using an internal standard (methyl heptadecanoate) added prior to the extraction steps. The extractives dissolved in the black liquor were isolated by a ternary liquid-liquid extraction scheme using diethyl ether, methylated with fresh diazomethane, and the resin- and fatty acids methyl esters characterized by GC and GC-MS. The extractives present in the pulp were isolated (removed) by a Soxhlet extraction procedure with methanol and" the resin- and fatty acids fractions characterized as above. Resin- and fatty acids surviving the high-temperature pulping process, were found mainly in the black liquor. After the 60 min cook, the black liquor contained 78.1% and 71.6% of resin- and fatty acids, respectively, while the pulp retained 11.7% and 8.2%, respectively of the extractives originally present in wood. "Lignin fraction I" adsorbed 10.2% and 20.2% of the resin- and fatty acids, respectively. Contrarily, if all of the lignin is precipitated (Lignin fraction II). prior to liquid/liquid extraction of the black liquor with diethyl ether, 98% and 60.4% of the resin- and fatty acids co-precipitate with the lignin and 2.0% and 39.6%, respectively, remain dissolved in the aqueous filtrate. Industrial organosolv lignin isolated after solvent pulping of pine was thus shown to contain most (98%) of the resin acids and 39.6% of the fatty acids normally found in pines. Although not tested, it is supposed that lignins isolated by precipitation from the black liquor after organosolv pulping of other species cannot be considered as "pristine lignins" as described hitherto in the technical literature, since such lignins are heavily contaminated by the extractives of the wood species. In light of these findings all data on chemical and physical characterization of organosolv lignins and their reactivity will have to be reexamined and reassessed to remove the effect of the extractives as contaminants. / Forestry, Faculty of / Graduate

The commercial rotary dryers used to dry wood wafers (of approximate dimensions 0.63 mm thick, 50 mm wide and 76+ mm long) for the production of panelboard are modified versions of agricultural dryers and have not been designed for the optimal drying of wood wafers. The lack of available information on wafer drying necessitated that the first goal of this research was the characterization of wafer drying behaviour. After the important parameters of wafer drying were identified, the applicability of fluidized bed technology to wafer drying was assessed and an industrial size dryer was designed. The proposed fluidized bed wafer dryer was then compared to a commercial rotary dryer in terms of energy efficiency. Wafer drying behaviour was investigated in two factorial experiments. Three lengths of wafers (25 mm, 44 mm and 63 mm) were individually dried in a 0.15 m draft tube at temperatures of 90°C, 120°C and 150°C. The statistical analysis of the resultant drying rate curves showed that the drying behaviour of aspen wafers was influenced by the effect of wafer length on the external heat and mass transfer rates to the wafer surface, and on the length of internal pathways for bulk flow and diffusion of water. The external drying conditions had a decreasing effect on drying rate until about 10% moisture content at which time drying became limited by internal heat and mass transport. The initial assessment of fluidized bed technology for wafer drying used a 0.15 m semi-cylindrical column for the determination of wafer drying rate curves and wafer behaviour in a fluidized bed of inert particulate solids at excess superficial velocities of 0.25 to 1.0 m/s. Wafer drying times in a bed of 0.5 mm sand at 150°C were about 40% of the drying times for wafers dried by forced convection of air at the same temperature and twice the superficial velocity (~ 1 m/s). Wafer movement in the fluidized bed followed the circulation patterns of the emulsion phase and was thus dependent on the bubbling behaviour of the bed. A minimum excess superficial velocity of 0.25 m/s (depending on distributor design) was required to prevent permanent settling of the wafers to the distributor. Preliminary experimentation on a 2-compartment bed showed that wafers could be circulated through the two compartments in near plug flow. However, the application of this technique to a 4-compartment continuous fluidized bed wafer dryer was unsuccessful because of the separation of sand and wafers caused by slugging beds in two of the compartments. A preliminary design was prepared for an industrial size, 5-compartment fluidized bed wafer dryer to approximate plug flow of wafers by a series of well-mixed fluidized beds in series. The design calculations showed that this dryer was more efficient in terms of energy and plant space than a conventional triple pass rotary dryer. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Passage of fibres suspended in water through apertures of dimensions greater than a fibre length and less than a fibre diameter has been examined at flow conditions approximating those in a pulp screen (large velocity parallel to the wall upstream of the aperture compared to the flow velocity within the aperture). Fibre behaviour was characterized in terms of three components: penetration of the leading tip into the aperture, rotation of the fibres on the downstream edge of the aperture, and fibre bending. Dimensionless numbers for each of these factors were derived from simple mass and force balances of fibres at an aperture entry. Experimental measurements of the magnitude of fibre passage were made on a single aperture located in a flow channel and in multiple apertures in a device simulating a commercial pulp screen in cross-section. For stiff fibres, it was found that fibre passage changed greatly with the ratio of fibre length to aperture width (L/W). When L/W was less than 2, the relationship between fibre passage and aperture velocity was approximately an exponential curve. The passage data correlated well with the penetration parameter. On the other hand, when L/W > 2, up to measured values of L/W = 6, the relationship between fibre passage and aperture velocity corresponded to a cumulative probability distribution curve. This latter behaviour, and the absence of a correlation with penetration and rotation parameters, was ascribed to contact between the tip of the rotating fibre and the upstream wall of the aperture. This was confirmed by experimental observations. Flexible long (L/W > 2) fibres showed behaviour between the two cases described above. The above observations were found to hold qualitatively for elevated concentrations up to a crowding factor of 4, multiple apertures, and the presence of pulses induced by a rotor of the type found in pulp screens. Accordingly, it appears that the findings are likely to hold in pulp pressure screens. An implication of this finding is that long stiff fibres may be best separated from short ones by choosing an aperture size such that L/W > 2 for the long fibre fraction and < 2 for the short fibre fraction. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Longitudinal air permeability measurements of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] outer sapwood from three trees of different seed sources and growth locations were determined on microsections about 500-700 microns thick, dried by air-seasoning and solvent-seasoning. The specimens were successively reduced in length from 3.6 to 0.4 cm. Darcy's law was found to be invalid with respect to specimen length. Sapwood earlywood longitudinal air permeability was found to be a sensitive barometer of seasoning effect on pit aspiration. The objective was to determine where the variations in margo porosity were significant, and hence applicable to problem of Douglas-fir permeability. The diameters of earlywood margo openings were measured directly from electron micrographs of un-aspirated (solvent-seasoned) pits. The margo measurement was assumed to represent one plane instead of the actual three dimensional structure, and the pores observed were the ones that controlled the rate of flow. Samples from the most, intermediately and least permeable specimens were selected and prepared for the evaluation of anatomical parameters of bordered pit membranes (margo area and margo porosity) as related to permeability. The effects of pit aspiration, tracheid length, total number of pits per tracheid, number of tracheids per square millimeter, and specific gravity on permeability were also assessed. Pit partial aspiration was found as the most important variable correlated with permeability. In an order of decreasing importance, pit partial aspiration, margo porosity and specific gravity together accounted for 94 per cent of total variability in permeability of solvent-seasoned earlywood. No statistical evaluations were made to compare the three trees with respect to their permeability and the measured parameters. / Forestry, Faculty of / Graduate