Thesis (doctoral)--Uppsala universitet, 1989. / Summary in English. Added t.p. with thesis statement inserted. Includes bibliographical references (p. 198-208).

Thesis (PhD)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 154-162).

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 136-143). Also available on the World Wide Web.

Thesis (M.A.I.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 214-224). Also available on the World Wide Web.

This thesis presents a numerical simulation study for the heat and mass transfer in- and out-side individual boards of a stack during kiln drying of wood and on the effect of side gaps between the boards. The objective is to optimize the drying process for efficiency and high quality products. A literature survey in the area is presented. The importance of the correct link between the transport processes in wood, and heat/mass transfer and fluid flow in the surrounding drying air is emphasized. Objectives, motivations and needs for the present study are also presented. This is followed by a detailed account of the governing equations, description of models, physical properties, and discretization and solution procedures used in the present study. A sample stack of planks has been used to evaluate the performance of various turbulence models and upwinding schemes of the CFX software developed for predicting the transport parameters in air. Given a typical stack set up for drying 105 x 105 mm western hemlock lumber, the effects of side gaps on surface coefficients are studied for different air velocities. An optimum gap size for maximum heat/mass transfer is suggested. The model developed for heat and mass transfer inside the wood is validated for a one dimensional case by comparing the numerical results with published results. The improved performance using a newly proposed relationship for the diffusivity of bound water has been demonstrated. Also a new relationship for the mass transfer boundary condition at the surfaces was proposed to incorporate the effect of the surface resistance. Relative effects of model unknowns in predicting the average moisture content and board center temperatures are discussed. A Fortran program was developed to solve the two-dimensional coupled heat and mass transfer equations inside the wood during the drying process. The model considers the changes in air temperature and humidity due to heat and mass transfer to and from the boards. The iterative SOR (Successive Over Relaxation) method was modified to increase accuracy and stability. Predictions for average and local moisture content are in good agreement with experiments. The effect of side gap on the drying process inside the wood was also examined. A plot of standard deviation of each board versus the board average moisture content is suggested for the judgement about the uniformity of the products. Results indicate that without using the extra gap size there exists a considerable difference between the maximum and minimum final average moisture content of the boards in each row. The first and last boards are usually over-dried. By using the previously suggested gap size the maximum difference of the final average moisture content is almost half the case without the extra gap. Average diffusion and surface coefficients are extracted from the experimental data of drying a stack without side gap. A software tool has been developed to solve the simple unsteady one-dimensional diffusion problem. Results are compared with experiments. The introduced method can be used to obtain the average diffusion and surface coefficients. / Graduate

Logging has traditionally been regarded as an occupation exceptionally prone to industrial conflict. This study analyses some of the forms which conflict takes, both between loggers and their employers and between loggers themselves, and suggests hypotheses to account for such conflict. A brief account of the early conditions in the industry is presented, with special emphasis on the hostility which existed between the men and their employers in the inter-war years as a result of the latter’s opposition to I.W.W. and unionizing activities. The argument is presented that the work ideology of the loggers which developed during this period was characterized by anti-authoritarian values and the concept of ‘freedom’ on the job. This ideology still survives today, though in somewhat diluted form. It is suggested that the increasing rationalization of the industry, and the imposition of strict work routines and increased discipline that this entails, runs directly counter to the loggers’ work expectations. The conflicts arising from this situation are documented by reference to material collected during a stay in a logging camp on Vancouver Island. A further source of conflict is seen to derive from the hazardous nature of logging operations. Because of the high fatality and injury rate in the occupation it is argued that the strict application of discipline demanded by the process of rationalization cannot be effectively imposed when those in positions of authority are held responsible for workers' safety. Evidence is also presented to show that the refusal to accept orders can be validated by reference to the moral priority of 'safety’ over the demands for productive efficiency. The dangers inherent in the job are also regarded as a ‘cost' which has to be offset by compensating 'rewards' of various kinds; the less acceptable the advantages are relative to disadvantages, the greater will be the loggers' propensity to reject authority. Because dangerous occupations have by definition heavy disadvantages for workers, it is suggested that they will thus be particularly prone to industrial conflict. / Graduate and Postdoctoral Studies / Graduate

The conversion of timber reserves into lumber is the largest industrial enterprise in British Columbia. The importance of this activity to the economy depends on a large provincial resource base and the ability to sell the processed goods to domestic and world markets. The objective of this study is to examine the dynamic nature of the, distribution and trends in Coast and Interior lumber trade (1947-1957) as they relate to the inter and intra-action or physical and human conditions in the source areas and markets. Even though Coast extraction of wood exceeds the allowable annual cut at the present level of exploitation and the Interior forests are being undercut, Crown control has been insufficient to effectively regulate the distribution of logging. Therefore, it was the, relative physical and economic accessibility of Interior timber, private cognizance of the limited size of Coast reserves, and Coast interest in the production of more highly processed wood commodities that resulted in the faster expansion of Interior sawmilling. In the future this trend will probably continue, since the full level of allowable annual, exploitation permits a much larger volume of extraction in the Interior. The distribution of sawmilling and their size are related to: (1) type and availability of transportation facilities, (2.) amenities available from service centers, and (3) duration of lumber processing. Provincial trade expanded fairly steadily to a peak in 1956 with the growth of world population and economic recovery after World War II, but this trend was modified by conditions in specific markets and by maritime freight rates. Interior shipments experienced this same increase as they became a more important, but not the major, source of British Columbia lumber. In contrast Coast shipments tended to fluctuate markedly. The major markets for provincial lumber were, respectively Canada, the United States, the United Kingdom, and Other countries (primarily the Union of South Africa and Australia). The Coast sawmills have a large water-borne trade with overseas markets and the United States' Atlantic ports, whereas the Interior, which depends on rail transport, sells almost exclusively to North America. British Columbia had difficulty in selling to the United Kingdom because of the direct competition for most lumber specifications with the closer sources in Sweden, Finland, and the Soviet Union. The volume of provincial shipments fluctuated with the level of British housing construction, import restrictions, and the release of stockpiled lumber. The major exporter to the Union of South Africa and Australia was British Columbia, but the United States and the Scandinavian countries, with the addition of New Zealand in the Australian market only, were also important suppliers. In both consuming areas the province has an advantage as the result of the type and size of lumber it can provide. The ability of South Africa and Australia to undertake a forestation program, with the expectation of a high degree of success, constitutes the greatest future threat to the British Columbia sawmills. If the consumers in Australia Increasingly accept the inferior grade of lumber domestically produced from radiata pine, a larger demand may also develop for the import of this commodity from New Zealand. Both of these changes would reduce the demand for British Columbia lumber. The Coast contributed the largest volume to the increased trade with the United States (1947-1957), but sales from this source have not expanded as rapidly or as steadily as those from the Interior. For both source areas the United States markets, in order of decreasing importance, are the Interior, the Atlantic ports, and the Pacific ports. The Coast Is the major supplier of all but the interior United States market where, because of its shorter rail connections, Interior British Columbia became the main source. The relative importance to British Columbia producers of these three market areas, and also the Canadian provincial markets, can be partially explained in terms of their alternate sources of supply, proximity, population, timber reserves, and lumber production. With its pronounced expansion of sales to Western Canada, the Interior became the major provincial shipper to the domestic market. Coast manufacturers have lost in relative importance, because they cannot compete on the unstable lumber market which has been created by Interior marketing practices. The clears and high quality, large dimensional British Columbia lumber sold domestically come mainly from the Coast, whereas common lumber comes primarily from the Interior. The relative size of the Canadian markets in decreasing order, British Columbia, Ontario, Alberta, Manitoba, Saskatchewan, Quebec, the Atlantic Provinces and the Territories. The Importance of consumer proximity to the source of production is clearly pointed out in Canada where the lumber output of each province provides the major source of competition to outside sources of supply. The trends and distribution of British Columbia lumber trade were not static, because the evaluation of supply and demand by both producers and consumers is continually changing. / Arts, Faculty of / Geography, Department of / Graduate

The main aspect of this study -was to analyze the changes which occurred in the British market between 1935 and the present. Changes have been manifold and have caused noteworthy fluctuations in the lumber export-import trade between British Columbia and the United Kingdom. The period under review was divided into five parts: pre-war (1936-1939), war (1940-1945), post-war (1946-1949), period after the devaluation of the pound sterling (1950-1952) and the present (1953-1954). Two additional chapters were included, one dealing with the future export trends, and the other treating briefly the historical growth of the lumber industry and its part in the provincial economy. A comparison was included of the mechanical and physical properties of Douglas fir, western hemlock, western red cedar and Sitka spruce and those of European whitewood and redwood. Housing activity in the United Kingdom was treated in detail throughout the thesis. The housing problem has been acute and will remain so in the next decade. Large quantities of softwood lumber are consumed in housing. Although the amount of lumber used per dwelling-unit decreased from 10-1/2 cubic metres to 7-1/2 cubic metres during the war, under the control system, it is expected to reach its former level on the anticipation that larger houses are to be built. During the pre-war period lumber exports from British Columbia increased remarkably, being larger by eightfold in 1936 than in 1931, and by twelvefold in 1939 than in 1931. The substantial housing program, preferential tariffs, trade promotion work and European Timber Exporters1 quota system, as well as British Columbia's lumber prices, contributed to the increased lumber exports to the United Kingdoms. During the war British Columbia's lumber played an important role in Great Britain. Total imports dropped to 25 percent of the prewar level and British Columbia supplied over fifty percent of them. The home production of softwood lumber increased about five times over pre-war level, reaching a peak in 1942 (344,000 standards). Timber control reduced consumption and controlled imports. The post-war reconstruction program in the United Kingdom caused heavy buying in British Columbia. In 1947, 31 percent of total British softwood lumber imports originated in this province. The dollar shortage in 1948 and 1949 forced the United Kingdom to decrease imports from British Columbia. The devaluation of the pound sterling made British Columbia's lumber expensive when comparing it with Russian and Scandinavian lumber. Increased prices and the inability to get lumber from Sweden and Finland after the outbreak of the Korean war, however, caused larger buying (about 400,000 standards) in British Columbia during 1951 and 1952. The present situation has been influenced by the decontrol of softwood lumber consumption in the United Kingdom which took place in November, 1953. The consumption is estimated to reach about 1,400,000 standards in 1954. An amount of 350,000 standards would be a fair share to be shipped from this province annually to the United Kingdom. A notable feature of the present is the willingness of Russia to export lumber (250,000 standards in 1954) to the United Kingdom. The import requirements of Great Britain are estimated to be 1,200,000 standards in I960 representing little more, than half of the pre-war level. They will have to be imported from outside Europe, mainly from Russia and British Columbia. Although this province is a source of high quality lumber, it is recommended that the British market be developed mainly for lower quality lumber by means of reasonable prices, and care in production and shipping. United Kingdom imports from British Columbia will depend upon its dollar purchasing power. This could be increased by two-way trade between Great Britain and Canada. During the period under review proportionally more and more western hemlock was shipped to Great Britain. The ratio between Douglas fir and western hemlock dropped from 1 to 7 of pre-war, to 1 to 4 in wartime and 1 to 2 in 1952. Since there is more mature western hemlock timber than Douglas fir on the coast from where the future exports are expected such a change in favour of western hemlock is an important achievement. / Forestry, Faculty of / Graduate

The application of high velocity liquid jets for corrugated board cutting was investigated as a possible new method of slitting operations. Eleven types of corrugated board ranging from 91 pounds per 1,000 square feet board weight (125 psi - nominal burst test) to 297 pounds per 1,000 square feet (350 psi - burst test) were selected for the study. Plain water or water with polymer additive were used as the cutting fluids. The conditions under which cutting of corrugated boards was carried out were as follows: nozzle diameters 0.0082 and 0.0102 in., pressure levels 20,000, 30,000 and 40,000 psi; feed rates 300, 500 and 700 fpm. The obtained results indicate that slitting speeds with high velocity liquid jets are well above those achievable by the existing conventional methods. It has also been shown that the use of a low concentration of polyethylene oxide (Polyox WSR - 301) resulted in a marked increase in cutting efficiency as compared with plain water. Measurements of liquid retention after cutting.-have shown that wetting of corrugated boards during the cutting operation is insignificant and as such can be neglected. It has been demonstrated that the edgewise compression strength of corrugated board, cut with the liquid jet, is almost twice that cut with the typical conventional slitter. Based on the analysis of scanning electron micrographs it has been observed that the principal failure mechanism during cutting with high velocity liquid jet involves breaking of the interfibre bond with resulting separation of fibres. Corrugated board cutting with high velocity liquid jets has been found to eliminate crushing and tearing of the board as well as dust generation. The concept provides a means to reduce trim waste and particle contamination. Jet cutting is ideally suited for numerically controlled systems and appears to lend itself for adaptation to commercial application. / Forestry, Faculty of / Graduate