Conceptual models of wood formation suggest that trees with large crowns produce low quality wood, but few studies have explicitly examined the relationship between crown size and wood quality. In this study, I examine how crown size influences the strength and stiffness of wood, as measured by Modulus of Elasticity (MOE) and Modulus of Rupture (MOR), using 42- and 72-old year plantation white spruce (Picea glauca) from Ontario, Canada. Mechanical properties were determined from 10x10x140 mm mini-clear samples (n=657), selected from a radial gradient at three heights within the stems. Non-linear mixed-effects models showed that strength and stiffness significantly decreased with crown size, and that MOE and MOR were best predicted by cambial age and crown ratio. The results suggest that the models could be used in conjunction with remotely sensed data to identify high quality timber prior to harvest.

Conceptual models of wood formation suggest that trees with large crowns produce low quality wood, but few studies have explicitly examined the relationship between crown size and wood quality. In this study, I examine how crown size influences the strength and stiffness of wood, as measured by Modulus of Elasticity (MOE) and Modulus of Rupture (MOR), using 42- and 72-old year plantation white spruce (Picea glauca) from Ontario, Canada. Mechanical properties were determined from 10x10x140 mm mini-clear samples (n=657), selected from a radial gradient at three heights within the stems. Non-linear mixed-effects models showed that strength and stiffness significantly decreased with crown size, and that MOE and MOR were best predicted by cambial age and crown ratio. The results suggest that the models could be used in conjunction with remotely sensed data to identify high quality timber prior to harvest.

In this paper. I analyze how political, economic, and administrative issues were major factors in the BC Liberal government's creation of a complex hybrid operating structure for BC Ferries. The model evolved as the result of a number of circumstances, including the former NDP government's "fast ferry" debacle and the Liberal government's decision to conduct a Core Services Review of all government services, including those provided by Crown corporations. BC Ferries' new structure has similarities to other administrative models that have been introduced as a result of New Public Management initiatives and other factors in a number of Westminster jurisdictions. The resulting operating entities are having significant impacts on the nature and scope of public accountabilities and on reporting structures.

Crown architecture affects tree growth through the control of leaf area and its display. Yet the linkages between crown structure, leaf traits, and productivity of elite selections of forest trees and responses to intensive silviculture are not fully understood. It was hypothesized that trees with crown and leaf traits governing efficient light capture and photosynthesis at the canopy scale would be the most productive. To this end, families of loblolly (Pinus taeda) and slash pine (Pinus elliottii) were grown at three experimental sites in the West Gulf Coastal Plain of Texas and Louisiana under two silvicultural treatments, including repeated fertilization with control of competing vegetation (HI), and a control (C) consisting of fertilization at planting. Families and species differed in crown traits and aboveground productivity, and genotype differences increased throughout the first 5 years of stand development. Crown shape was important for light interception and growth initially, but at the onset of canopy closure, crown size, stand leaf area and its distribution within crowns affected canopy light interception and tree growth. Among all families and treatments, aboveground biomass productivity was positively related to absorbed photosynthetically active radiation (APAR) and canopy photosynthesis. Light-use efficiency (ε) varied from 0.41 to 0.56 g MJ-1 among families and was lowest in slash pine. Variability in aboveground biomass growth was related more to stand leaf area and APAR than to differences in light-use efficiency in these young stands. Leaf physiological, chemical and morphological attributes changed within crowns in accordance with developing light availability gradients. Physiological attributes, such as net photosynthesis, were better predictors of family performance when integrated at the canopy level than leaf level in the examined pine species. Crown size, light absorption, and aboveground growth generally ranked higher in the HI treatment than in the control, although the effects of the intensive silvicultural treatments did not differ statistically. Family performance was independent of treatment. Crown and canopy attributes, such as high leaf area index and large crowns with low leaf area density per crown volume, may be useful in the selection of highly productive genotypes of loblolly and slash pine under intensive silviculture.

The common discotic mesogen molecules are known to have a flat structure, comprising a rigid core, e.g., polynuclear aromatic structure, and a ring of four to nine flexible aliphatic side chains. We take the electron deficient heterocyclic hexaazatriphenylene (HAT) as our central core and readily synthesized by the condensation of hexaketocyclohexane with the respective 1,2-bis-alkoxy-4,5-diaminobenzene. The new molecules with electron deficient discotic liquid crystal properties are successfully.

This thesis contains two parts of materials characterization. Part I is a poly(butylene succinate) copolymer with minor amount of 2-methyl-propylene succinate. In the second part, six kinds of implant crowns made from five dental casting alloys and one Zircoina ceramic are studied. Copolyester was synthesized and characterized as having 89.0 mol% butylene succinate units and 11.0 mol% 2-methyl-propylene succinate units in a random sequence, revealed by NMR. Isothermal crystallization kinetics was studied in the temperature range (Tc) from 75 to 91 ¢XC using differential scanning calorimeter (DSC). The melting behavior after isothermal crystallization was studied by using DSC by varying the Tc, the crystallization time and the scanning rate. DSC curves showed triple melting peaks. Multiple melting behaviors indicate that the upper melting peaks are associated with the primary and the recrystallized crystals, or the crystals with different lamellar thickness. As the Tc increases, the contribution of recrystallization slowly decreases and finally disappears. A Hoffman-Weeks linear plot gives an equilibrium melting temperature of 118.4 ¢XC. The spherulitic growth rates of this copolyester were measured at Tc between 69 and 91 ¢XC using an optical microscope equipped with a CCD camera. The kinetic analysis of the growth rates gave a regime II-III transition temperature at about 77.2 ¢XC. Rectangular specimens of 10 ¡Ñ 9 ¡Ñ 4 mm were made of five kinds of casting alloys, separately. They were treated in the same procedures as crowns did. Their surfaces after oxidation were analyzed using x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Rectangular specimens after applying porcelains were ~5.5 mm thick. The cross-section areas were studied by electron probe micro analyzer (EPMA). Standardized maxillary premolar crowns were fabricated with five different alloys and one Zircoina ceramic. The crown specimens were positioned in a custom testing apparatus and vertically loaded on the middle of the occlusal surface with a universal testing machine at a crosshead speed of 0.5 mm/min until fracture. Mean values of load at fracture were calculated in each alloy and compared with a one-way analysis of variance and Tukey test (£\=0.05). The fracture surfaces were examined using SEM. The results of XPS, SEM and EPMA indicate that on the surface there was an oxidation layer (or interface between metal and ceramic) of indium (or/and tin, zinc, etc.). The concentration of oxide metal increased, whereas that of precious metal decreased, from bulk to interface. The fracture strength and the fracture path of the crowns were correlated with the metal-ceramic interface of the rectangular specimens that was characterized using XPS, SEM and EPMA.

No description available.

Revised; Originally Published 2002 / 4 pp. / Pine bark beetles in Arizona are generally of the genus Ips or Dendroctonus. Fading foliage in the tree is often the first sign of a beetle attack. Prevention is best practiced since control is not possible once the beetles have successfully colonized the tree. Colonization is dependent upon trees being in a vulnerable condition caused by stress from various agents and site conditions.

No description available.

In this paper. I analyze how political, economic, and administrative issues were major factors in the BC Liberal government's creation of a complex hybrid operating structure for BC Ferries. The model evolved as the result of a number of circumstances, including the former NDP government's "fast ferry" debacle and the Liberal government's decision to conduct a Core Services Review of all government services, including those provided by Crown corporations. BC Ferries' new structure has similarities to other administrative models that have been introduced as a result of New Public Management initiatives and other factors in a number of Westminster jurisdictions. The resulting operating entities are having significant impacts on the nature and scope of public accountabilities and on reporting structures.