Thesis (Ph.D.)--North Carolina State University, 2004. / Includes vita. Includes bibliographical references (p. 173-177). Also available online via the North Carolina State University Library website (http://www.lib.ncsu.edu/).

Hamburg, Universiẗat, Diss., 2001. / Dateiformat: zip, Dateien in unterschiedlichen Formaten.

Aim of this thesis is to examine the specific influences on the business development of cash flows for each year. Is important to assess the impact of credit obtained in 2006 to build a grinding lines on the cash flows of the enterprise.

The turbulent flow of air through the annular gap between two tubes was studied experimentally, both with the tubes concentric and with the inner tube at eccentricities of 50% and 100%. Air velocities were measured using small traversable impact tubes. The shear stresses on the boundaries were studied both by measuring the pressure gradient and by means of a calibrated shear probe attached to the inner tube. For all three annuli complete nondimensional velocity profiles were obtained at Reynolds numbers around 55,000 and the variation of average friction factor with Reynolds number was studied in the Reynolds number range 20,000 -55,000. The variation of local shear stress around the surface of the inner tube was obtained for the eccentric annuli. The results for the concentric annulus agree well with previous investigations. For the eccentric annuli the results are compared qualitatively with Deissler and Taylor's semi-theoretical investigation. The agreement is not good and this is thought 'to show that the Deissler-Taylor method is not applicable to annuli. It is concluded that the study of velocity profiles in non-symmetrical ducts is of little help in obtaining quantitative heat transfer data. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

Numerical solutions of the velocity profiles for laminar, stratified flow of two immiscible, Newtonian liquids in a circular pipe were determined for viscosity ratios of 1, 10, 100 and 1000 at various interface positions. These results were used to calculate the theoretical volumetric flow rate enhancement factors, power reduction factors and hold-up ratios, which for laminar flow depend only upon the viscosity ratio and the interface position. The maximum volumetric flow rate enhancement factors and maximum power reduction factors, and the corresponding input volume ratios, were determined. Dimensionless quantities were used, making the results applicable to any pipe diameter, any liquid viscosities and any pressure gradient, providing laminar flow of both phases prevails. The theoretical results were compared to the experimental results of Russell, Hodgson and Govier for horizontal cocurrent flow of a mineral oil and water in a circular pipe. As expected, the two sets of results differed considerably in the region of turbulent water flow. As turbulence decreased however, the difference decreased, until in the laminar region very good agreement between the theoretical and experimental results was obtained. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Numerical solution of the Navier-Stokes equation was successfully accomplished, using an adaptation of the relaxation technique of Jenson, for axisymmetric flow past single oblate and prolate spheroids at particle Reynolds numbers up to 100. The aspect ratio of the spheroids varied between 0.999 (nearly perfect sphere) and 0.2. For low aspect ratios the surface pressure and vorticity distributions showed a marked difference from those of a sphere. The appearance of the wake bubble behind a spheroid was found to be a strong function of the particle shape. Numerical solutions were also obtained for two-dimensional symmetric flow past elliptical cylinders, with the flow parallel to the major axis for aspect ratios of 0.995 to 0.2 at Reynolds numbers up to 90, and with the flow parallel to the minor axis for an aspect ratio of 0.2 at Reynolds numbers up to 40. The numerical solution was found to be less stable than the corresponding three-dimensional axisymmetric case. The variation of the total drag coefficient with Reynolds number for the spheroids and the elliptical cylinders of various aspect ratios was not much different from that of a sphere and a circular cylinder, respectively. The results for both the spheroids and the elliptical cylinders showed a steady trend with Reynolds number from Stokes and/or Oseen flow to boundary layer flow. Happel's free surface cell model and Kuwabara's zero vorticity cell model were employed for the study of creeping flow past swarms of aligned spheroids and clusters of aligned elliptical cylinders. Large deviations of the Kozeny constant from its commonly assumed value of 5 for packed beds were found by both models for particles which deviate significantly in shape from a sphere or a circular cylinder. In general, Happel's free surface model predicted lower total drag coefficients than did Kuwabara's zero vorticity model for both the swarms of spheroids and the clusters of elliptical cylinders. Contours of the streamlines, equi-vorticity lines and equi-velocity lines are presented. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

This thesis investigates two new approaches to the use of multiple antibody labels in flow cytometry. On the experimental side, we develop the Multiplex Labelling method, which allows the number of simultaneous antibody labels to exceed the number of fluorochromes, thus overcoming the technical limitations imposed by the number of available fluorochromes and fluorescence measuring channels. On the theoretical side, we construct a dynamic interpretation of immunofluorescent flow cytometry data, which allows information on the kinetics of cell division and differentiation to be extracted. The first part of the thesis discusses multiplex labelling. Chapter 1.1 presents the theory of this method, a reconstruction formula on which the algorithm for multiplex labelling data processing can be based, and a case study illustrating the use of this method in the triple labelling analysis of murine thymocytes. A murine thymocyte subset not previously described by flow cytometry is observed in this study for the first time. Chapter 1.2 describes the Immunofluorescence Tomograph, a microcomputer-controlled device for the preparation of multiplex labelling solutions. This device makes possible the routine use of multiplex triple labelling, by carrying out a complicated and time consuming part of the experimental protocol. The second part of this thesis deals with the dynamic interpretation of the data. Chapter 2.1 describes the theory of skeletal analysis, which is a coarse topological analysis of immunofluorescent flow cytometry data, concerned with the outlines of regions where the distribution is significantly different' from zero. Chapter 2.2 investigates the finer topological details of the distributions resulting from division and/or differentiation. We show that, under certain reasonable conditions, these distributions acquire simple forms, which can be easily analyzed and compared to actual data. Chapter 2.3 presents murine thymocyte triple labelling data obtained by multiplex analysis. These include data on the embryonic thymus (from day 15 to day 20 of embryonic development), as well as the neonate and adult thymus. The methods developed in chapters 2.1 and 2.2 are applied, and two partial thymocyte lineages are defined. One of these lineages has not been previously reported. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The objective of this study is to develop guidelines for the design of sampling programs to predict groundwater discharge. A method for choosing a preferred sampling strategy from a set of alternatives is presented. A framework is outlined, in the form of an objective function, that incorporates both the cost of collecting data and the worth of data. A monetary value is assigned to the worth of hydraulic conductivity data by examining the economic losses associated with the uncertainty in predictions of groundwater discharge. The method is applied to the problem of designing a sampling program that measures hydraulic conductivity for predicting discharge from a rapid infiltration pond. Hydraulic conductivity data are generated for hypothetical hill slopes using a stochastic finite element model. A set of sampling strategies are selected. For each sampling strategy, the value and location of measurements and the uncertainty in the spatial variation of hydraulic conductivity are incorporated using conditional simulations. Estimates of pond discharge are calculated from the stream function solution and compared to the actual value of pond discharge for the hypothetical site. The root mean square error is used to quantify the uncertainty in discharge predictions. A set of alternative sampling strategies are compared using the objective function. Prediction uncertainty, measured by the root mean square error, is sensitive to both the structure of the heterogeneities and the location of measurements. Sampling schemes that lead to good estimates of the ensemble mean and standard deviation will not necessarily lead to good predictions of discharge. The goal of sampling schemes should be to collect data in key locations of the flow domain and to identify the spatial variation in hydraulic conductivity in a cost effective manner. For predicting discharge from a rapid infiltration pond, locating one or two initial boreholes below the pond is the preferred strategy for a majority of the cases tested. When the measurements are spaced evenly throughout the flow domain, important shallow layers may be missed that have a large influence on pond discharge. Increasing the number of boreholes does not necessarily lead to more certain predictions of pond discharge or to lower values of the objective function. Considerable uncertainty in discharge predictions can exist even with a relatively large number of measurements. While an optimal strategy exists, there is potential for significant variation in prediction uncertainty at individual sites. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

When building process-intensive web applications, developers typically spend considerable effort on the exchange of specific data entities between specific web pages and operations under specific condi- tions, as called for by business requirements. Since the WWW infrastructure provides only very coarse data exchange mechanisms, we introduce a notation for the design of fine-grained conditional data flows between user interface components. These specifications can be interpreted by a data flow controller that automatically provides the data entities to the specified receivers at run-time, relieving developers of the need to implement user interface data flows manually.

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