No description available.

No description available.

No description available.

Although several enzymes presumed to be part of the delignification/kraft pulp biobleaching system of the white-rot basidiomycete Trametes versicolor have been studied, characterized, and even exploited as pulp treatments, the complete system remains poorly understood. Little is known about which enzymes are essential for delignification, how they are regulated, or whether there remain unknown enzymes essential to wood decay in this system. Auxotrophic mutants of T. versicolor 52J were developed and characterized. Plasmid pUC18 was complemented with the T. versicolor 52J genome to create a gene library. Transformation with this plasmid-gene library converted argB and ade2 auxotrophs of T. versicolor 52J to prototrophy. Attempts to rescue the plasmids responsible were unsuccessful. Several different pre-existing plasmid constructs were examined for their potential as selectable markers on the fungus. One of these, pGPhT, worked well at conferring phleomycin resistance. Given that there are now available partial or complete sequences for four T. versicolor laccases, the single cellobiose dehydrogenase, and a lignin peroxidase isozyme, these genetic tools should be very useful in dissecting the mechanisms of white-rot delignification.

In the early 1990s polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) contamination of fish was widely associated with bleached kraft pulp mills. Regulations were put into place in Canada and elsewhere to reduce or eliminate the presence of these chemicals in pulp mill effluents. The industry quickly introduced treatment and process changes such as elemental (ECF) and total chlorine free (TCF) bleaching, which resulted in dramatically reduced PCDD/F concentrations in pulp mill effluents. However, PCDD/Fs may remain a concern for the receiving environment near bleached kraft pulp mills due to their tendency to persist in sediments and bioaccumulate in aquatic biota. Several studies conducted in the early 1990s reported significantly elevated levels of PCDD/Fs in white sucker (Catostomus commersoni) exposed to bleached kraft mill effluent (BKME). Particularly high concentrations were observed in the receiving environment of two mills in northern Ontario. The first mill, located in the town of Terrace Bay, discharges effluent into Jackfish Bay, Lake Superior. The second mill is located in Smooth Rock Falls, Ontario and discharges effluent into the Mattagami River where effects have been observed in fish collected downstream of the pulp mill. Over time, both mills have undergone a number of process upgrades, including a transition to 100% chlorine dioxide (ClO2) substitution. In 2006 the Tembec Smooth Rock Falls Pulp and Paper Mill closed permanently, while the mill in Terrace Bay has gone through a number of temporary shutdowns and is currently in the process of transitioning to a dissolving pulp process. Temporal changes in PCDD/F contamination was examined in white sucker historically exposed to BKME in Jackfish Bay and the Mattagami River, following mill process changes and closures. Historical data was summarized from studies conducted in the 1990s and analyzed along with liver tissue of male white sucker collected from each location in 2011 and 2012. The body burden of each fish was analysed using Toxic Equivalency (TEQ) calculations to account for concentration and relative toxicity of 2,3,7,8??? substituted PCDD/F congeners. At Jackfish Bay, concentrations of PCDD/Fs in surface sediment and dated sediment cores were used to document the spatial and temporal pattern of PCDD/F contamination in relation to historical process upgrades and operational changes at the mill. PCDD/Fs measured in white sucker liver samples collected from Jackfish Bay during gonadal recrudescence in the fall illustrate a decrease in mean TEQ from 74.2 ?? 20.9 pg???g-1 in 1991 to 3.34 ?? 2.05 pg???g-1 in 2012. These values were slightly elevated compared to the remote reference location at Mountain Bay, Lake Superior, which exhibited a mean TEQ of 1.88 ?? 0.45 pg???g-1 and 1.06 ?? 0.69 pg???g-1 in white sucker collected in fall 2011 and 2012, respectively. Although below consumption guidelines, trace levels of PCDD/Fs persist in fish collected from Jackfish Bay and these concentrations are suspected to reflect sediment contamination in Moberly Bay (part of Jackfish Bay). A unique PCDD/F contaminant profile, dominated by 2,3,7,8??? tetrachlorodibenzo???p???dioxin (TCDD) and dibenzofuran (TCDF), was observed in white sucker and sediment collected from Jackfish Bay. Analysis of surface sediment collected throughout Jackfish Bay revealed elevated PCDD/F concentrations, compared to reference areas in Lake Superior. TEQ values measured in surface sediment from the depositional areas of Moberly Bay exceeded the Canadian Council of Ministers of the Environment (CCME) guidelines. In 1991 PCDD/F contamination, reported as mean TEQ, of white sucker collected downstream of the pulp mill outfall in Smooth Rock Falls reached levels of 111 ?? 86.2 pg???g-1. At the time, the mill utilized molecular chlorine (Cl2) in the bleaching sequence and employed primary effluent treatment. A dramatic decline was observed in PCDD/F concentrations of fish collected in 1993 and 1995, corresponding to implementation of 100% ClO2 substitution in the bleaching process. PCDD/F contamination in white sucker collected from the Mattagami River in 2011 and 2012 were similar upstream (0.53???1.49 pg TEQ???g-1) and downstream (0.75???2.87 pg TEQ???g-1) of the historical pulp mill outfall at Smooth Rock Falls, suggesting a return to background condition following the 2006 mill closure. Levels of 2,3,7,8???TCDD and 2,3,7,8???TCDF in liver tissue of fish collected downstream declined drastically compared to concentrations measured in 1991. The PCDD/F congener profile observed in white sucker downstream in 2011 and 2012 was more similar to fish collected from the reference site upstream than exposed fish collected in 1991. No sediment depositional areas suitable for taking a core sample were found on the river downstream of Smooth Rock Falls due to the nature of the system. This study supports the conclusion that particulate (POM) and dissolved organic matter (DOM) from continuous inputs of effluent were likely the primary source of PCDD/Fs to fish in these receiving environments, with only a small contribution from surface sediment. Results indicate a decreasing trend in PCDD/F contamination of white sucker historically exposed to bleached kraft pulp mill effluent in the receiving environments of Jackfish Bay and the Mattagami River, consistent with mill process upgrades to eliminate the use of elemental chlorine from the bleaching sequence. Current levels of PCDD/Fs measured in white sucker collected from these locations suggest a return to background condition.

ACPEL devices were fabricated onto various paper substrates. The dielectric and phosphor layers were mask printed, a PEDOT:PSS/SWCNT ink was inkjet-printed for the cathode and a translucent conductor was applied with a paintbrush for the anode resulting in a maximum luminance of 8.05 cd/m2 at 300 VAC and 60 Hz. It was found that the conductivity of the PEDOT:PSS/SWCNT ink on the various paper types was affected by the coating and paper thickness. Novel ACPEL devices were also fabricated by incorporating paper as the dielectric layer of the device. The maximum luminance achieved was 7.24 cd/m2 at 300 VAC and 60 Hz. It is shown that the dielectric constant of the paper and hence the performance of the resulting EL device may be enhanced by filling the sheet with BaTiO3 and by the surface treatment of the sheet.

ACPEL devices were fabricated onto various paper substrates. The dielectric and phosphor layers were mask printed, a PEDOT:PSS/SWCNT ink was inkjet-printed for the cathode and a translucent conductor was applied with a paintbrush for the anode resulting in a maximum luminance of 8.05 cd/m2 at 300 VAC and 60 Hz. It was found that the conductivity of the PEDOT:PSS/SWCNT ink on the various paper types was affected by the coating and paper thickness. Novel ACPEL devices were also fabricated by incorporating paper as the dielectric layer of the device. The maximum luminance achieved was 7.24 cd/m2 at 300 VAC and 60 Hz. It is shown that the dielectric constant of the paper and hence the performance of the resulting EL device may be enhanced by filling the sheet with BaTiO3 and by the surface treatment of the sheet.

No description available.

North America is the world’s largest pulp and paper producing region as well as the largest consuming region. An understanding of market integration is critical for designing relevant policies since it is important to improve national welfare and ensure long-run competitive market equilibrium. In addition, it is crucial for the Canadian industry to maintain the competitiveness for its pulp and paper products in the world market, because any deterioration in the performance of the Canadian pulp and paper industry will have negative social and economic impact on the well-being of Canada and affect Canadian balance of payment. This thesis contains three essays that investigate the market integration of the combined markets of Canada and the US, and the competitive position of Canadian pulp and paper products in the US market. The first essay presents an econometric analysis of spatial integration of the US and Canada newsprint markets as reflected in newsprint prices. It applies the Johansen multivariate cointegration procedure to test the law of one price for five regional markets (British Columbia, Ontario, Quebec, US east, US west) of newsprint using monthly data for the 1988 to 2004 period. Preliminary data analysis shows that all price series are non-stationary I(1) processes. The hypothesis that the Law of One Price (LOP) holds for all five regional newsprint markets simultaneously was not supported by the Johansen multivariate test. The LOP was also tested for national markets, and it was found to hold between US west and US east newsprint prices. The results suggest that there is a single newsprint market in the US, whereas there are several distinct newsprint markets in Canada. The second essay examines the degree of market integration among US import markets for three pulp and paper products, and further analyses the dynamic interaction between US domestic and US import markets. Persistence profile results show that long-run equilibrium exists in the US import markets for three pulp and paper products of interest; moreover, given a system-wide shock, a new equilibrium could be reached in a relatively short period. Forecast error variance decomposition suggests that US markets are critical since shocks to domestic US prices for relevant pulp and paper products explain a substantial amount of movements in import prices. The third essay studies substitution between main categories of imported pulp and paper products and between imported and domestic pulp and paper products in the US market. A restricted translog subcost function approach was employed to derive the elasticity of substitution. The results suggest that Canadian pulp and paper products are still competitive and have maintained their competitiveness in the US market. However the consecutive demand decline for pulp and paper in the US has brought hard times to Canada. It seems that if Canadian pulp and paper industry wants to retain a dominant position in the world market place, it will have to create global reach and develop new markets.

With increasing energy costs and competitive pressures, interest has increased in surveying installed pumps for potential energy savings. Field pump efficiency tests are required to assess pumping performance and help to identify improvement opportunities. This work concerns the on-site measurements of pulp-suspension pumping efficiency. This involves the measurement of pump head, flow rate and power consumption. Provided that consistent flow measurements are available, it is possible to reliably and non-invasively measure actual pump system efficiencies in pulp suspension flow, with a minimum process disturbance. As part of a most appropriate measurement-procedure study, four portable nonintrusive flow meters were evaluated on site for pulp suspension flow. The Fast Fourier Transform Doppler was found to be the most suitable for a pulp mill pump survey. Efficiency measurements were performed on six pump systems with motors between 100 and 700 HP. It is shown that as-installed pump efficiency can be used to help predict the degradation of the pump and also its effect on the pumping system’s operation. A system approach analysis was performed in each case, which can be effective in assessing system performance and finding potential enhancements. The use of variable speed drives allows the operating point to move along the system curve, requiring less energy to drive the pump. VSD of larger motors are expensive and their profitability compared to other modification alternatives should always be carefully checked by calculations based on accurate on site measurements and life cycle costs. Finally, in this survey of six pump systems, significant potential savings of around 30% of present power consumption were found.