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Comparative Evaluation Of Exact Extreme Value Stochastic Flood Model For Mixed Populations., Senarath T. B Ekanayake
Comparative Evaluation Of Exact Extreme Value Stochastic Flood Model For Mixed Populations., Senarath T. B Ekanayake
LSU Historical Dissertations and Theses
Two alternative formulations of the exact extreme value stochastic flood model are presented in explaining the behaviour of observed flood series resulting from mixed climatological processes. As a marginal distribution for flood exceedances, a more flexible Weibull distribution is introduced in the place of the traditional exponential distribution. The asymptotic predictive performances of both the exponential and Weibull model formulations are evaluated in terms of relative bias (BIAS) and relative root mean square error (RMSE) of quantile estimation. The model with Weibull marginal performs well over the exponential for population conditions shown to exist in most of the observed flood …
On Bubble Columns. (Volumes I And Ii)., Nicholas William Geary
On Bubble Columns. (Volumes I And Ii)., Nicholas William Geary
LSU Historical Dissertations and Theses
There exists a narrow operating window in bubble columns where the motion is so gentle that the normally dominating forces of coalescence and breakup no longer define column conditions. This behavior is synonymous with operation in the bubbly flow regime. During experimentation, two distinct hydrodynamic regions were observed; close to the sparger, the liquid was well mixed, whilst in the remainder of the column a dispersive flow model was determined to be appropriate. In the entrance zone, the isotropic turbulence theories of Kolmogoroff adequately represented transport behavior. This finding implies that a churn-turbulent environment, wherein bubbles are continuously reformed, will …
Feedback Linearization Of Nonlinear Systems: Robustness And Adaptive Control., Weon Ho Kim
Feedback Linearization Of Nonlinear Systems: Robustness And Adaptive Control., Weon Ho Kim
LSU Historical Dissertations and Theses
Feedback linearization provides an effective means of designing nonlinear control systems. This method permits one to have an exactly equivalent linear system by using a coordinate transformation and state feedback. Once the nonlinear system is transformed to a linear system, one can proceed with well developed control technologies for linear systems. Feedback linearization is based on a model of the real system. If there is mismatch between the model and the real plant, feedback linearization does not yield an exactly linear system. The question of robustness then arises: will a controller based on the model be stable when applied to …
A Study On The Effects Of Additives On Selective Hydrogenation Of Trace Acetylene Over Palladium Catalysts., Yeung Ho Park
A Study On The Effects Of Additives On Selective Hydrogenation Of Trace Acetylene Over Palladium Catalysts., Yeung Ho Park
LSU Historical Dissertations and Theses
The effects of both carbon monoxide (as a gas phase additive) and potassium (as a catalyst additive) on the selective hydrogenation of acetylene over Pd/Al$\sb2$O$\sb3$ was studied by deuterium tracer experiments combined with Kemball's steady-state treatment and temperature programmed reaction (TPR). The TPR of acetylene and ethylene in hydrogen, which was attempted in this study for the first time, enabled the investigation of the behavior of the adsorbed species on Pd. CO addition to the reaction mixture significantly increased the probability of ethylene desorption during ethylene deuteration while minor effects due to CO displacement of hydrogen were observed for acetylene …
Interfacial Adhesion In Rayon/Nylon Sheath/Core Composite Fibers., Weiying Tao
Interfacial Adhesion In Rayon/Nylon Sheath/Core Composite Fibers., Weiying Tao
LSU Historical Dissertations and Theses
Rayon/nylon sheath/core composite fibers with enhanced adhesion were produced using a wire coating type process. One objective of this research was to determine an effective coupling agent and the most appropriate application conditions for maximum interfacial adhesion in the rayon/nylon bicomponent fibers. The second objective was to characterize the interfacial adhesion between the core fiber and the rayon skin. It was found that fumaric acid (FA) was an effective adhesion promotor for rayon/nylon composite fibers since it has difunctionality and steric hinderance necessary to form covalent bonds to both layers. After removal of the spin finish by water washing the …
Low-Pressure Phase Equilibria Of Heavy Aromatic Compounds., Ajay Gupta
Low-Pressure Phase Equilibria Of Heavy Aromatic Compounds., Ajay Gupta
LSU Historical Dissertations and Theses
Phase equilibrium diagrams for systems containing compounds found in coal liquids and heavy crude oil are useful in designing separation processes and also in testing and developing of thermodynamic models. Solid-liquid equilibrium (SLE) data are easy to obtain compared with vapor-liquid equilibrium (VLE) data for systems that are solid near room temperature, because the solids melt to liquids and have relatively high boiling points. It may be possible to extrapolate activity coefficients derived from SLE data to higher temperatures and thus predict vapor-liquid equilibrium. This dissertation presents new SLE and VLE data for compounds related to coal liquids. The problem …
Specific Cell Adhesion And Its Application In Mixed Culture Fermentations., Yeou-Fu Hwang
Specific Cell Adhesion And Its Application In Mixed Culture Fermentations., Yeou-Fu Hwang
LSU Historical Dissertations and Theses
Cell adhesion mediated by bonds between receptors in the cell membrane and ligands on a solid support is referred to as specific cell adhesion. This work focused on the application of specific cell adhesion in control of mixed culture fermentations and on the development of solution methods of mathematical models for cell adhesion. Through various experimental techniques, a model two-strain mixed culture system was obtained. This system was used to explore the possibility of mixed culture control through selective adhesion of particular subpopulations. It was found that through a proper reactor design and operating procedure, the coexistence of the mixed …
Three-Dimensional Modeling Of Reaction Injection Molding., Yu-Wen Lo
Three-Dimensional Modeling Of Reaction Injection Molding., Yu-Wen Lo
LSU Historical Dissertations and Theses
Since increasing more complex RIM molds are being used in industry, the goal of this research is to develop a model which can be used to predict the dynamic filling front, hot spots, and air entrapment in molds. In this research a method to simulate the RIM process by considering both the filling and curing stages in variously shaped molds for unsteady state three dimensional state cases was developed. This model can be used to predict not only the temperature and conversion changes with time but also the front position changing as a function time. Using given physical and chemical …