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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

The resistance of Douglas-fir to sulfite pulping

Hoge, William Henry 01 January 1954 (has links)
No description available.
42

The effect of the neutral sulfite semichemical cook on the hemicelluloses of aspenwood

Lea, David Chester 01 January 1953 (has links)
No description available.
43

Anaerobic alkaline degradation of D-glucose, cellobiose, and derivatives

MacLeod, J. Martin (James Martin) 01 January 1975 (has links)
No description available.
44

The design, preparation, characterization, and preliminary reactions of an insoluble lignin model

Apfeld, Patrick B. 01 January 1986 (has links)
No description available.
45

Measurement of delignification diversity within kraft pulping processes

Boyer, Brian S. 05 1900 (has links)
Institute of Paper Science and Technology / Thesis (Ph. D) -- Institute of Paper Science and Technology, 1998.
46

Kinetics and mass transfer in the chlorination of draft pulp fibers.

Pugliese, Sebastian C., III 05 1900 (has links)
No description available.
47

Displacement washing of wood pulp

Poirier, Nicole A. January 1986 (has links)
No description available.
48

Kinetics of alkaline delignification of black spruce wood

Rivers, J. A. (John Abbot) January 1982 (has links)
A previously proposed kinetics equation describing the delignification of wood in soda-anthraquinone (AQ) liquors was shown to be valid under isothermal conditions, and was extended to describe variation in initial alkali charge. Kinetics expressions were derived for soda-amine, kraft (soda-hydrosulfide ion) and soda-ethanol delignification under isothermal conditions over various ranges of additive charge. In each case, the total delignification observed after a given time of pulping could be described as the sum or two contributions: (i) that due to the sodium hydroxide alone, and (ii) that due to the additive (AQ, amine, hydrosulfide ion or ethanol). Rate constants were determined at various temperatures and apparent Arrhenius activation energies were calculated for soda-AQ, soda-amine and kraft delignification. Although the calculated activation energies were found to be similar, the forms of kinetic expressions obtained suggested that the role of AQ in alkaline delignification may differ from that of an amine or hydrosulfide ion. The effects of various combinations of additive pairs on delignification were investigated and the results suggested that interactions occur. Under certain conditions, delignification in soda-AQ-amine and kraft-AQ liquors, respectively, could be described as the sum of the effects of the sodium hydroxide alone, the amine or hydrosulfide ion, and a term dependent upon the anthraquinone.
49

Reduction of sulfur release through indigester oxidation in kraft pulping

Bakke, Bruce W. 05 1900 (has links)
No description available.
50

The leaching of lignin and carbohydrate from high yield pulp fibres suspended in water /

Willis, Jocelyn M. January 1984 (has links)
When high yield chemimechanical sulphite pulp fibres were suspended in water, both lignin and carbohydrate were leached out of the pulp. The rate of leaching fitted a theory developed previously for the diffusion of macromolecules through the water-swollen fibre wall. The average intrafibre diffusion coefficients for lignin and carbohydrate were several orders of magnitude lower than the free diffusion of these macromolecules in solution. Leaching over a long period indicated a polydispersity of diffusion coefficients. This was related to an increase with time in the molecular weights of macromolecules removed from the fibre. Although the rate of leaching increased markedly with temperature, the diffusion coefficient of lignin decreased, while that of carbohydrate increased by a factor higher than that predicted by the Stokes-Einstein equation. These contrasting results were interpreted in terms of the molecular weights of the diffusing species and hydrogen bonding of carbohydrate to the fibre wall. The rate of leaching decreased with an increase in pulp yield, increasing cationic strength and pH of the wash water, decreasing refining energy, pretreatment of pulp with formaldehyde, and the use of polyethyleneoxide/alum retention aid in the wash water. Decreasing pH of the cooking liquor and the use of anthraquinone in the pulping increased the leaching of lignin but did not affect the leaching of carbohydrate. The effects observed could be related either to swelling or degradation of the fibre wall.

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