This thesis includes three studies. The first study examined how reductions in light availability and changes in soil chemistry that occur as conifers establish in aspen stands, differentially affects the regeneration success of aspen and conifers. We found that aspen were more sensitive to changes in light and soil then subalpine fir. For aspen, reduced light and conifer influenced soils significantly reduced height, biomass, photosynthesis and the production of secondary defense compounds. Subalpine fir seedlings were significantly reduced in photosynthesis, biomass and R:S under lower light conditions but showed no differences in physiology or growth when grown on the contrasting soil types. Subalpine fir seedlings were significantly reduced in photosynthesis, biomass and root:shoot ratio under lower light conditions but showed no differences in physiology or growth when grown on the contrasting soil types. Results from this study suggest that reduction in light and changes in soil chemistry associated with conifer succession place constraints on aspen growth and defense capacity, which may contribute to losses in aspen cover under longer disturbance return intervals. The second study looked at regeneration dynamics of aspen and conifers as forest stands transition from canopy gaps to aspen dominated canopies to conifer dominated canopies. We found that as overstory conifer density increases, aspen decrease in density, basal area, and seedling establishment. Conifers were shown to establish closer to aspen as the canopy increased in conifer density. As this proximity relationship extended into the canopy there is increased mortality in both aspen and subalpine fir, suggesting both facilitation and competition. Our third study looked at the physiological effects of smoke exposure on growth and primary and secondary metabolic responses of deciduous and conifer tree species. Twenty minutes of smoke exposure resulted in a greater than 50% reduction in photosynthetic capacity in five of the six species we examined. Impairment of photosynthesis in response to smoke was a function of reductions in stomatal conductance and biochemical limitations. In general, deciduous species showed greater sensitivity than conifer species. Smoke had no significant affect on growth or secondary defense compound production in any of the tree species examined.

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Thesis (M.S. - Renewable Natural Resources)--University of Arizona, 1980. / Includes bibliographical references.

Thesis (MS)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Clayton B. Marlow. Includes bibliographical references (leaves 44-53).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (PH. D.)--University of Minnesota, 1931. / Cover title. Vita. "Reprinted from Ecological monographs, 8 ... April, 1938." "Literature cited": p. 243-246.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 83-92).

Yes / In this work, the process of ethane recovery plant was simulated for the purpose of Front End Engineering Design. The main objective is to carry out a series of simulation using Aspen HYSYS to compare recovery of ethane from Joule Thomson (JT) Valve, Turbo-Expander and Twister Technology. Twister technology offers high efficiency, more ethane recovery and lower temperature than JT valve and turbo-expander process. It lies somewhere between isenthalpic and isentropic process due to its mechanical configuration. Three processes were compared in terms of recovery of ethane. To conduct the simulations, a real gas plant composition and design data were utilized to perform the study for comparison among chosen technologies which are available for ethane recovery. The same parameters were used for the comparisons. Effect of operating conditions including pressure, temperature, and flow rate as well as carbon dioxide on the recovery of ethane was examined.