In this dissertation we report new theoretical results—both analytical and numerical—concerning a variety of polymeric systems. Applying path-integral and differentiable manifolds techniques, we have obtained original results concerning the statistics of a Gaussian polymer embedded on a sphere, a cylinder, a cone and a torus. Generally, we found that the curvature of the surfaces induces a geometrical localization area. Next we employ field theoretical (instanton calculus) and differential equations techniques (Darboux method) to obtain approximate and exact new results regarding the average size and the Green function of a Gaussian, one-dimensional polymer chain subjected to a multi-stable potential (the tunnel effect in polymer physics). Extending the multiple scattering formalism, we have investigated the steady-state dynamics of suspensions of spheres and Gaussian polymer chains without excluded volume interactions. We have calculated the self-diffusion and friction coefficients for probe objects (sphere and polymer chain) and the shear viscosity of the suspensions. At certain values of the concentration of the ambient medium, motion of probe objects freezes. Deviation from the Stokes-Einstein behavior is observed and interpreted. Next, we have calculated the diffusion coefficient and the change in the viscosity of a dilute solution of freely translating and rotating diblock, Gaussian copolymers. Regimes that lead to increasing the efficiency of separation processes have been identified. The parallel between Navier-Stokes and Lamé equations was exploited to extend the effective medium formalism to the computation of the effective shear and Young moduli and the Poisson ratio of a composite material containing rigid, monodispersed, penetrable spheres. Our approach deals efficiently with the high concentration regime of inclusions.

1a. Two model porous media and a precise drying protocol are employed in numerical simulation of fluid configurations in partially saturated porous media. Over a substantial range of partial saturation $N\sb{L},$ the liquid-vapor configurations are inhomogeneous on a length scale that is a sensitive function of $N\sb{L}.$ Several measures of the characteristics of fluid configurations are developed. Details of the fluid configurations are found in the study of $p(x;\ell,N\sb{L}),$ the probability density for a porous medium of partial saturation $N\sb{L}$ to contain a piece of material of size $\ell\sp{d}$ having partial saturation x. This probability density is a gauge of inhomogeneity and appears importantly in NMR studies of porous media. 1b. The equations governing magnetization evolution in fluid filled pore systems are developed. In pore systems with a range of pore sizes (and/or decay rates) the magnetization evolution is described exactly by a spectrum of decay rates, leading to multiple exponential decay. We study this spectrum of decay rates as a function of coupling strength between pores using perturbation theory, effective medium theory, and matrix diagonalization. The spectrum of decay rates evolves from the individual pore decay rate distribution, at zero coupling, to a delta function distribution, at infinite coupling. The effect of coupling between pores is important in NMR studies of temperature dependence of characteristic decay rates in porous media. 2. The equation of motion describing a borehole elastic system (BES) is studied in the form of a perturbation problem, i.e. as the sum of terms describing a model elastic system (MES) and terms describing the departure of the BES being studied from the MES. The MES is chosen such that the departure terms in the BES equation of motion are small. The Green tensor for an infinite, azimuthally symmetric borehole is developed. As an illustration of the perturbation technique, the consequences of a mudcake layer on the borehole wall are explored. Comparison of first order perturbation calculations confirms the perturbation method is a valid technique for probing small changes to a model elastic system.

Bose-Einstein Condensation is a macroscopic occupation of bosons in the lowest energy state. For atoms, extremely low temperatures are required to observe this phenomenon. For photons, condensation has been demonstrated at room temperature, requiring a large number of particles (N ∼ 77000) and very complicated setup. Here we study the possibility of observing BEC of light at room temperature with a much lower number of particles by leveraging disorder in a dielectric material. There is no constraint in the number of photons in the system like in the previous research. We investigate what happens to photons once they are put inside a cavity with a disorder. The analysis is carried out by using time-dependent quantum Langevin equations, complemented by a thermodynamic analysis on quantum photons. Both approaches give the same expression for the critical temperature of condensation. We demonstrate that photons in a disordered cavity with arbitrary initial statistical distribution reach thermal equilibrium and undergo a Bose-Einstein Condensation if the temperature is sufficiently reduced. In our model we demonstrate that the temperature is related to the losses of the system. At this state, photons follow Boltzmann distribution. It is demonstrated that by only varying the strength of disorder, it is possible to change the critical temperature of the phase transition, thus making condensation possible at room temperature. This work opens up the possibility to create new types of light condensate by using disorder.

The main task of this diploma thesis is a draft design low-regenerative feedwater heater. There is conducted thermal and hydraulic calculation of this device. After that there is detaily described the method for controlling the temperature of the outlet water. Conclusion includes calculations for sizing wall thickness of the main tires. Projection drawing is part of the work as a supplement.

The starting point of this project was the sparsely built housing areas, dominated by tall towerblocks, from the Million-program era, to me exemplified by Bredäng, in southwestern Stockholm. Here, there are eight floors high towerblocks placed at an even distance of 50 meters from each other. The initial idea was look at ways to condensate by exploiting empty space in-between tall residential houses, generally.   The project was to change direction, however. What I had labeled as a generic Million-program area, is in fact very much a specific site. Time has passed since Bredäng were built, for 50 years, the site, that already in its cradle were unusually nature-oriented, has grown, and developed an identity. My strategy formed into being taking care of the features I found to be the obvious qualities, and translate them into new buildings on the site. Bredäng is not inner city, and doesn’t need city-oriented additions, but the green areas, on the other hand, is worth preserving, as is the drama in the tall thin houses framing the views, and the contrasts between the shrubby, small-scaled ground level and the grand open spaces.   If I was to state a conclusion it would be that I think that a general strategy for condensation in sparsely planned residential areas is to see each area as its own, and to start with looking at what is already there. / Utgångspunkten för projektet var Miljonprogrammets glesbebyggda höghusområden, som för mig har kommit att exemplifieras av Bredäng, i sydvästra Stockholm. Här är åtta våningar höga skivhus är utplacerade med jämna mellanrum på ca 50 meter.  Tanken var att titta på hur man kan förtäta genom att utrymmen mellan höga skivhus exploateras, generellt.   Projektet kom dock tidigt att ta en annan riktning. Det jag rubricerat som ett typexempel är en specifik plats. Lång tid har passerat sedan Bredäng byggdes, i 50 år har platsen som redan när den byggdes var ovanligt naturpräglad och speciell, vuxit, utvecklats och fått sin identitet. Min strategi blev att använda det jag tyckte var de mest framträdande kvaliteterna i området och försöka omsätta dem i tillägg på platsen. Bredäng är inte innerstad och behöver inte stadsmässiga tillägg, grönområdena, däremot, är värda att ta tillvara, liksom det dramatiska i de stora, höga husen som ramar in vyerna, och kontrasterna mellan det snåriga, småskaliga på marknivå, och det storslagna, öppna ytorna.   Om jag skulle formulera en slutsats är det att jag tror att en generell strategi för att förtäta glesbebyggda områden är att betrakta varje enskilt område som specifikt och utgå från vad som redan finns där.

The plant pigments constitute a fascinating group of compounds whose constitution has only recently been partially clarified. Roughly speaking, there are two main groups of pigment: the plastids, associated with the protoplasmic structure of plants, and the anthocyanins, generally found in solution in the cell sap. The term “anthocyanin” is derived from the Greek, “antho” signifying flower and “cyan” meaning blue, and was introduced by the botanist Marquart in 1835 to designate the blue pigments of flowers. It has since been extended to include all of the pigments of this group, the anthocyanin pigments being responsible for the innumerable shades of blue, red, violet, mauve, and magenta that are found in nature.

Three existing condensation heat transfer models are validated using 544 experimental data points for pure refrigerants and refrigerant mixtures. The Cavallini et al. (1999) model predicts well with the pure-refrigerant data sets. However, the Cavallini et al. (1999) model fails to predict the refrigerant-mixture data sets. The Yu and Koyama (1998) model, which is applicable for the pure refrigerants only, fails to predict most of the R22 data sets. The Kedzierski and Goncalves (1999) model, which is applicable for both pure refrigerants and refrigerant mixtures, yields relatively high mean absolute deviations for most of the pure-refrigerant data sets. The Kedzierski and Goncalves (1999) model does not account for the mass transfer thermal resistance in refrigerant mixtures. A new pure-refrigerant model and a new refrigerant-mixture semi-empirical model have been developed. Both the new models successfully predict the experimental data for pure refrigerant and for refrigerant mixtures.

No description available.

This theoretical study has been undertaken in order to provide insights into the steady two-dimensional laminar film condensation heat transfer on an isothermal vertical flat wall and a cylindrical surface. Condensation is given to both the pure water vapor and water vapor-air mixture. Only the saturated state of the bulk vapor is considered. The effects of liquid-vapor resistance, gas-solubility in the condensate, thermal diffusion and diffusion thermo are neglected. The presence of air as non-condensing gas has been fully accounted for in this study. The physical properties of the condensate liquid are taken to be those of saturated water at the appropriate temperature. The properties of the vapor region are considered to be constant except for the density of the mixture. The method of solution is based on the numerical techniques of laminar boundary layer theory. By using liquid-vapor interface matching, an approximate integral solution is obtained. In this study, it was found that the presence of a small amount of air as a non-condensing gas in the water vapor-air mixture plays a decisive role in decreasing the condensation heat transfer. The decrease is more pronounced at lower bulk temperature, TV, and higher values of (TV-TW). As the mass fraction of air in the bulk, W∞, increases, the heat transfer decreases monotonically.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24090号 / 医博第4866号 / 新制||医||1059(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 岩田 想, 教授 林 康紀, 教授 松田 道行 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM