Much of the stochastic groundwater literature is devoted to the analysis of flow and transport in Gaussian or multi-Gaussian log hydraulic conductivity (or transmissivity) fields, Ydx_5ln Kdx_ (x being a position vector), characterized by one or (less frequently) a multiplicity of spatial correlation scales. Yet Y and many other variables and their (spatial or temporal) increments, DY, are known to be generally non-Gaussian. One common manifestation of non-Gaussianity is that whereas frequency distributions of Y often exhibit mild peaks and light tails, those of increments DY are generally symmetric with peaks that grow sharper, and tails that become heavier, as separation scale or lag between pairs of Y values decreases. A statistical model that captures these disparate, scale-dependent distributions of Y and DY in a unified and consistent manner has been recently proposed by us. This new `` generalized sub-Gaussian (GSG)'' model has the form Ydx_5Udx_Gdx_ where Gdx_ is (generally, but not necessarily) a multiscale Gaussian random field and Udx_ is a nonnegative subordinator independent of G. The purpose of this paper is to explore analytically, in an elementary manner, lead-order effects that non-Gaussian heterogeneity described by the GSG model have on the stochastic description of flow and transport. Recognizing that perturbation expansion of hydraulic conductivity K5eY diverges when Y is sub-Gaussian, we render the expansion convergent by truncating Y's domain of definition. We then demonstrate theoretically and illustrate by way of numerical examples that, as the domain of truncation expands, (a) the variance of truncated Y (denoted by Yt) approaches that of Y and (b) the pdf (and thereby moments) of Yt increments approach those of Y increments and, as a consequence, the variogram of Yt approaches that of Y. This in turn guarantees that perturbing Kt5eYt to second order in rYt (the standard deviation of Yt) yields results which approach those we obtain upon perturbing K5eY to second order in rY even as the corresponding series diverges. Our analysis is rendered mathematically tractable by considering mean-uniform steady state flow in an unbounded, twodimensional domain of mildly heterogeneous Y with a single-scale function G having an isotropic exponential covariance. Results consist of expressions for (a) lead-order autocovariance and cross-covariance functions of hydraulic head, velocity, and advective particle displacement and (b) analogues of preasymptotic as well as asymptotic Fickian dispersion coefficients. We compare these theoretically and graphically with corresponding expressions developed in the literature for Gaussian Y. We find the former to differ from the latter by a factor k5hU2 i= hUi 2 (h i denoting ensemble expectation) and the GSG covariance of longitudinal velocity to contain an additional nugget term depending on this same factor. In the limit as Y becomes Gaussian, k reduces to one and the nugget term drops out. Plain Language Summary Much of the stochastic groundwater literature is devoted to the analysis of flow and transport in Gaussian or multi- Gaussian log hydraulic conductivity fields, Y(x), (x being a position vector). Yet Y, as well as many other variables and their increments DY, are known to be generally non- Gaussian. One common manifestation of non- Gaussianity is that whereas frequency distributions of Y often exhibit mild peaks and light tails, those of increments are generally symmetric with peaks that grow sharper, and tails that become heavier, as separation scale or lag between pairs of Y values decreases. A statistical model that captures these disparate, scale- dependent distributions of Y and DY in a unified and consistent manner has been recently proposed by us. This new generalized sub- Gaussian (GSG) model has the form Y(x) 5U(x) G(x) where G(x) is (generally, but not necessarily) a multi- scale Gaussian random field and U(x) is a non- negative subordinator independent of G. The purpose of this paper is to explore analytically lead-order effects that non-Gaussian heterogeneity described by the GSG model have on the stochastic description of flow and transport. Our analysis is rendered mathematically tractable by considering mean uniform steady state flow in an unbounded, two-dimensional domain of mildly heterogeneous Y.

This dissertation examines the wealth effects of bank mergers on bidder, target, and combined firm shareholders for a sample of 785 mergers during the period 1980-2000. The dissertation employs two unique bank event study methodologies to calculate abnormal returns for bidder, target and combined firms. The first methodology is a modified market model that controls for shocks common to the banking industry. The second is an EGARCH (1,1) model that adjusts for the violated regression assumptions of the traditional market model event study. Namely, it controls for the linearity assumption, heteroskedasticity, and the correlation in the error term. The results of both methodologies reveal that target shareholders enjoy significantly positive abnormal returns, whereas the bidder shareholders experience significantly negative abnormal returns. Overall, announcements of bank mergers generate positive wealth effects for the combined shareholders. However, the evidence presented in this dissertation, to some extent, underscores the importance of the choice of models describing stock returns in examining the impact of bank mergers. In addition, when mergers are analyzed to determine the effects of relative size and relative book-to-market values, we find evidence that the relative size significantly affects the target, bidder and combined firm return; method of payment is also found to be significant in abnormal returns. Moreover, we find that the number of bidders affects only the bidder returns, while book-tomarket values are irrelevant factors. Availability Restricted: Release the entire work for campu

Ridership in the New Orleans region is down, and transit agencies are challenged to increase transit performance. Transit professionals expect many benefits from cooperation between transit systems in the region including an increase in efficiency and effectiveness. The question is "do these cooperative initiatives between transit agencies improve transit performance?" To answer this question a survey has been held to collect data regarding regional initiatives implemented by transit agencies. In addition data were collected from the transit agencies websites. The analysis focused on the comparison between agencies that implemented regional initiatives versus agencies that did not implement any regional initiative. From the analysis it appears that although agencies have implemented cooperative initiatives they are not very convinced that it had a significant impact on transit performance. Further, results show that cooperation might have some positive impact on transit performance, but are not as convincing as literature and transit professionals expect

Disinfection is the final and very important step of wastewater treatment to maintain healthy ecosystems. Although chlorination is the most prevalent wastewater disinfection method, there are serious safety concerns and ecological problems associated with its use. The purpose of this study was to test the feasibility of using a HydroFLOW 60i unit for wastewater disinfection, as an alternative to chlorination. The study was performed using two different reactors, namely, a bench-scale laboratory batch reactor, and a continuous flow, pilot unit. Using the batch reactor, it was found out that the HydroFLOW 60i unit is effective to kill bacteria; however, modifications to this mode of operation would be required in order to increase the disinfection efficiency and to decrease the detention time. When the continuous flow system was run using a hydraulic detention time of 10 minutes and a single pass through the HydroFLOW unit, the E. coli removal efficiency was negligible. Further research is needed to determine the most economical and efficient reactor configuration in order to make the HydroFLOW unit competitive with conventional wastewater chlorination.

This thesis is a part of the major EU project EE-Highrise which is a part of the European 7th Framework Research Program (FP7-ENERGY). In order to demonstrate and test new technologies and concepts, a demo building has been constructed in Ljubljana, the capital of Slovenia. The approach during the development of the building has been to consider all its elements with the purpose to increase the energy efficiency and sustainability of the building. Umeå University’s objective is to develop regional specific models of the demo high-rise building. The objective of this thesis is to evaluate whether a simplified model of the high rise building, Eco Silver House, can meet the passive house classifications in four selected cities; Ljubljana, Sibenik, Umeå and Dubai and then to suggest improvements of the models for the different regions. Drawings of the building were provided along with an IFC file for construction of the model in PHPP. The simulation tool used for simulations, PHPP, contained all necessary tools for designing a properly functioning Passive House. By preparing an energy balance, the annual energy demand of the building was calculated based on input related to building characteristics. Results from the simulations have then been compared to the requirements for the German Passive House classification. The performance of the building in Umeå has also be compared to the Swedish passive house standards. Improvements to the climate shell and the ventilation system were after that examined depending on the results. It was shown that it is possible to construct regional specific models that fulfill the passive house requirements in three of four regions. The model achieved passive house standard without any additional energy efficiency measures in Ljubljana and Šibenik while a combination of measures was needed to fulfill all the criteria’s in Umeå. The Swedish requirements used for evaluation of the model in Sweden were easier to fulfill since they have been developed for the cold climate present in Umeå. Since no regional passive house classification was used to evaluate the performance of the model in Dubai the cooling and primary energy demand exceeded the limiting criteria’s. The energy efficiency measure with reduced window area had the greatest impact on heating and cooling demand in all climates. This measure should be included in all future models which also is suggested by parallel studies on similar models of the same building. The only climate where an increased U-value of the external envelope resulted in improved performance of the model was in Šibenik. For all the other climates where a lowered U-value was implemented did the overall performance improve. / EE-Highrise (European 7th Framework Research Program.

Wheat (Triticum aestivum L. cv Minaret) was grown long-term under CO₂ partial pressures of 36 and 70 or 100 Pa with various N applications (4 to 23 g m-2 N), to test hypotheses of N re-allocation: 1) a decrease in N from leaves to other organs, 2) a relative decrease in N from Rubisco to other photosynthetic components. Elevated CO₂ did not affect phenology, main stem leaf appearance, the pattern of N allocation throughout the plant, or the fraction of crop N in grain at harvest, but 1) stimulated biomass and yield by 5 to 20% over the N range used, and 2) caused a faster loss of N and components from flag leaves during grain-fill. Responses of photosynthesis to varying pCi were fitted, and rates of maximal carboxylation and non-photorespiratory respiration estimated. The former, was proportional to Rubisco content, and light-saturated photosynthetic rate at 70 Pa CO₂ was proportional to A TP-synthase. Potential photosynthetic rates at 70 Pa CO₂ were calculated, compared with observed, and used to estimate excess investment in Rubisco. The excess was greater in high N treatments than low, declining as leaves senesced. The fraction of Rubisco estimated to be in excess, was strongly dependent on leaf N content, increasing from - 5% in leaves with 1 g N m-2 to -40% in leaves with 2 g N m-2. Growth at elevated CO₂ usually decreased the excess somewhat, but only as a consequence of a general decrease in leaf N, given that relationships of components to leaf N content were independent of CO₂ and N treatment, demonstrating that no direct CO₂ effect on N allocation within leaves had occurred. It is concluded that there is scope for improving the N-use efficiency of C₃ crop plants in elevated CO₂ conditions, by genetic manipulation to decrease the amount of Rubisco.

Small and Medium size Wind Turbines (SMWTs) can be used for the production of electricity in residential areas, or integrated into hybrid systems, which makes them more attractive in remote areas with difficult access to electricity from the grid. However, many of the SMWTs are installed in locations with low wind speeds, reducing remarkably their annual energy output. Furthermore, SMWTs are typically operated in sub-optimal conditions because they are not completely understood in the real environment. In a design stage, typically a wind tunnel is used to determine the aerodynamic efficiency, but latest research suggests that a turbine in the field behaves differently, especially when the wind is unsteady. Therefore, the aerodynamic performance of a wind turbine tends to be different in the field. Unfortunately, field testing is expensive, and requires long term measurements, especially for small turbine manufacturers. This thesis investigates four topics that could greatly impact the performance of a wind turbine: 1. the wind resource, and how by the spectral modelling of its unsteadiness it is possible to design better turbines and control systems, to adequately react in gusty wind conditions in order to maximise energy harvesting; 2. resource assessment using short-term measurements of wind, to reduce the uncertainty in annual energy production; 3. loss modelling in the generator and power converter to optimise overall efficiency of a wind energy conversion system; and 4. aerodynamic performance identification based on field measurements. On each of these fields, new methods are proposed and validated to improve the existing knowledge. Regarding loss modelling and optimisation, an algorithm to find the global optimum in a system with losses is proposed and tested in an 800 W vertical-axis wind turbine owned by Airborne- Energy Ltd. The experimental data collected in the field, confirms the validity of the approach and its ability to find the optimum despite the high inertia of the turbine, and the unsteadiness of the wind. It is shown that a control algorithm that seeks a global optimum, can increase the overall efficiency of the system, and reduces internal stress on the shaft and power electronics. Finally, as the optimisation algorithm developed in this thesis features the estimation of parameters for a turbine, the processed information can have two positive impacts for further study: detection of system faults and diagnostic of the health-state of the system; and, design specifications, as the manufacturer can have direct inputs of the performance of the turbine to make further improvements for new designs.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript. / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries