Thesis (Ph. D.)--University of Wisconsin, 1964. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves [357]-365.

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The purpose of this thesis was to analyse the supply of pulp and paper products in the three major producing provinces of Canada, namely British Columbia, Ontario and Quebec. A translog restricted profit function and its first partial derivatives were estimated using the iterative seemingly unrelated regressions procedure. Derived demand equations for energy, fibre, labour and supply equations for net market pulp, newsprint and 'other paper and paperboard", (net market pulp and 'all paper and paperboard' for British Columbia) were obtained with net supplies as a function of each input and output price. The success of the model in representing the industry was mixed. Derived demand own price elasticities were, in almost all cases, negative as expected a priori. Negative own price elasticities were also found in many end product supply functions suggesting a misspecification of the supply relationship. The unexpected supply function results bring up questions about the degree of competitiveness in pulp and paper markets, and thus the validity of using the perfectly competitive market assumption in empirical studies. Finally the model was evaluated in the context of using the results in a spatial equilibrium model of the North American pulp and paper sector. / Forestry, Faculty of / Graduate

Submitted in complete fulfilment for Masters Degree in Technology: Biotechnology, Durban University of Technology, 2013. / A comparative thermostability analysis of different partially purified xylanases from Rhodothermus marinus, Bacillus halodurans, Thermomyces lanuginosus and Pulpzyme HC was studied using differential scanning fluorometry (DSF), fluorescence spectroscopy and circular dichroism (CD). The R. marinus xylanase was found to have an optimum temperature and pH of 90oC and 6 respectively while the B. halodurans xylanase was optimally active at 70oC and a broad range of alkaline pH of 8 - 10. The commercially available xylanase from T. lanuginosus showed optimal activity at 50oC and pH 7 while the Novozyme xylanase Pulpzyme HC showed optimal activity at 60oC and pH 7. Fluorescence spectroscopy monitored the microenvironment and fluorescence emission of Trp residues. In their native folded state, Trp are generally located in the core of the protein but during unfolding they become exposed. The fluorescence changes as the enzyme undergoes denaturation due to conformational changes and exposure of Trp residues. Differential scanning fluorometry (DSF) monitors thermal unfolding of proteins in the presence of a fluorescent dye such as Spyro Orange. A wide range of buffers were tested for their ability to increase the xylanase stability. T. lanuginosus had the greatest increase in melting temperature with 0.73M Bis Tris pH 6.5 and peaked highest at 78°C. The B. halodurans xylanase exhibited high pH stability (pH 4-10) and exhibited very little change in melting temperature, from 74°C-77°C over the twenty four different conditions. The R. marinus xylanase had no increase in melting temperature showing a maximum melting temperature of 90oC. Circular dichroism (CD) measures unequal absorption of right- and left-handed circularly polarized light by the molecule. The xylanase from R. marinus exhibited the lowest ΔG of 34.71kJ at 90°C as was expected. The B. halodurans xylanase showed a much higher ΔG of -52.71 at its optimum temperature of 70°C when compared with the xylanases from R. marinus and T. lanuginosus. When comparing the three xylanases activities at 70°C, it can be seen that the B. halodurans xylanase exhibited a lower relative activity then both R. marinus and T. lanuginosus xylanases. All three techniques offered different information on the structure and function relationship. Fluorescence spectroscopy, the change in conformation due to fluorescence emission as a result of increased temperature and salt concentrations. DSF, optimal conditions for increased stability and activity at higher temperatures and CD, conformational changes, the fraction of folded protein and change in Gibbs free energy over a range of temperature. / National Research Foundation

Combustion properties of kraft black liquor solids were studied using a laminar entrained flow reactor. The tendency of black liquors to release fume (compounds containing Na⁺, K⁺, Cl⁻, SO₄²⁻, SO₃²⁻, S₂0₃²⁻ and C0₃²⁻) during combustion were observed at 1000°C. Black liquor solids with a size fraction of 63 to 100 μm were burned in a mixture of 4% 0₂ and 96% N₂ at a residence time of 0.67 seconds. Combustion properties of one black liquor (liquor #3) were studied by varying the solids feed rate from 0.47 to 1.08 g/min (liquor feed rate study). Combustion properties of five North American and Finnish black liquors were studied at a target solids feed rate of 0.73 g/min (liquor to liquor study). Black liquor fuming was observed to be a decreasing function of solids feed rate and an increasing function of excess oxygen. The appearance of char residues varied from black and porous at high solids feed rates to white and dense at low solids feed rates. Combustion may have been enhanced at low solids feed rates by liquor swelling due to a combination of heat and mass transfer effects and limited at high solids feed rates by inter-particle and bulk gas mass transfer limitations. For the liquor to liquor study, black liquors were observed to release fume differently. Chars produced during this study varied in appearance, indicating that the black liquors had unique combustion properties. Variations in temperature and mass transfer effects resulting from liquor swelling properties were likely responsible for the variability in liquor fuming behavior. The liquors that contained the most NaCl and had the highest anionic equivalents as C0₃²⁻ (or other chemical species) produced the most fume. Sodium vaporization varied from 25.2% to 33.7%: Liquors #2 and #5 vaporized the most sodium and also had the lowest concentrations of measured anions in their char residues. Potassium and chloride enrichment factors for the five liquors were slightly lower than those of common industrial boilers. Liquor #3 had a concentration of Cl⁻ that was (roughly) an order of magnitude higher than the other liquors studied; however, it also had the lowest chloride enrichment factor. / Graduation date: 2002

Graduation date: 1996

This project explored the feasibility of using fungi in a constructed wetland for the treatment of pulp mill effluent. The effluent is high in dissolved lignins (some of which are chlorinated), which have proven very difficult to degrade biologically. Mindful of work done with the (terrestrial) white rot fungi, especially Phanerochaete chtysosporium, the question is asked, Is there a fungus which can tolerate submerged conditions while degrading a significant amount of dissolved lignins? Two fungal species with lignin-degrading capability were isolated from submerged films in a log pond. These fungi have been evaluated for decolorization potential under different environmental conditions. Results of laboratory experiments show that one of these fungi, identified as Acremonium sp., was capable of 44% decolorization of pulp mill effluent under sterile, submerged, room temperature conditions. The fungal decolorization was evaluated both in floating cultures and as a film inoculated on wood chips. In addition, bench-scale examination of the potential of this fungus to decolorize pulp mill effluent in non-sterile conditions was completed. / Graduation date: 1994

Graduation date: 1994