Self-organized nanostructures of poly(4-vinylpyridine), polyaniline and polyamides due to metal complexation

Comb-shaped supramolecules are constructed using flexible polymers and semi-rigid conjugated undoped or doped conjugated polymers upon complexing Zinc dodecyl benzene sulphonate, Zn(DBS)₂. Selforganized nanostructures are formed in the bulk due to competing attractive interactions (coordination or water mediated hydrogen bonding) and repulsive polar/nonpolar interactions, showing characteristic long periods of ca. 30 Å.     

An existence result for superparabolic functions

We study superparabolic functions related to nonlinear parabolic equations. They are defined by means of a parabolic comparison principle with respect to solutions. We show that every superparabolic function satisfies the equation with a positive Radon measure on the right-hand side, and conversely, for every finite positive Radon measure there exists a superparabolic function which is solution to the corresponding equation with measure data.     

The BV-capacity in metric spaces

We study basic properties of the BV-capacity and Sobolev capacity of order one in a complete metric space equipped with a doubling measure and supporting a weak Poincaré inequality. In particular, we show that the BV-capacity is a Choquet capacity and the Sobolev 1-capacity is not. However, these quantities are equivalent by two sided estimates and they have the same null sets as the Hausdorff measure of codimension one. The theory of functions of bounded variation plays an essential role in our arguments. The main tool is a modified version of the boxing inequality.     

A risk approach by credibility theory

This paper attempts to treat some topics of risk theory by means of credibility theory. We study the risk aversion of an agent faced with a situation of uncertainty represented by a discrete fuzzy variable, the relationship between stochastic dominance and credibilistic dominance, and an index of riskiness of discrete credibilistic gambles. In the framework of an optimal saving credibilistic model, the way the presence of risk modifies the level of optimal saving is studied. The main tool of our investigation is an operator defined by B. Liu and Y. K. Liu by which to a discrete fuzzy variable one associates a discrete random variable with the same expected value as the former.     

Sobolev space properties of superharmonic functions on metric spaces

Our objective is to study regularity of superharmonic functions of a nonlinear potential theory on metric measure spaces. In particular, we are interested in the local integrability properties of a superharmonic function and its derivative. We show that every superharmonic function has a weak upper gradient and provide sharp local integrability estimates. In addition, we study absolute continuity of a superharmonic function.     

Local behaviour of solutions to doubly nonlinear parabolic equations

We give a relatively simple and transparent proof for Harnack’s inequality for certain degenerate doubly nonlinear parabolic equations. We consider the case where the Lebesgue measure is replaced with a doubling Borel measure which supports a Poincaré inequality.     

Harnack’s principle for quasiminimizers

Abstract We study Harnack type properties of quasiminimizers of the -Dirichlet integral on metric measure spaces equipped with a doubling measure and supporting a Poincaré inequality. We show that an increasing sequence of quasiminimizers converges locally uniformly to a quasiminimizer, provided the limit function is finite at some point, even if the quasiminimizing constant and the boundary values are allowed to vary in a bounded way. If the quasiminimizing constants converge to one, then the limit function is the unique minimizer of the -Dirichlet integral. In the Euclidean case with the Lebesgue measure we obtain convergence also in the Sobolev norm. Keywords: Metric space, doubling measure, Poincaré inequality, Newtonian space, Harnack inequality, Harnack convergence theorem Mathematics Subject Classification (2000): 49J52, 35J60, 49J27     

Glucose-induced changes in the optical properties of Intralipid

Photoacoustic and optical measurement techniques were used in this paper to study glucose-induced changes in Intralipid suspensions. Optical energy was provided by a Nd:YAG laser at 1064 and 532 nm and a picosecond laser module at 906 nm. As detectors, the setup employed a photoacoustic detector, PIN diode, and streak camera. Increasing the glucose content of the suspensions increased the refractive indices of the studied media. This served to decrease the refractive index mismatch between the background and the scattering particles and led consequently to decreased scattering, which then affected both the peak-to-peak value of the photoacoustic signals and the transmitted optical pulses. At 1064 nm, glucose changed the peak-to-peak value of the photoacoustic signal more in 1% than in 2% Intralipid. In addition, the glucose-induced change in the transmitted pulse amplitude was less noticeable at 532 than at 1064 nm in 1% Intralipid. The text was submitted by the authors in English.     

In situ and ex situ characterisation of oxide films formed on strained stainless steel surfaces in high-temperature water

A possible approach in describing the role of the environment in the phenomena behind initiation and propagation of a stress corrosion crack is to assume that the transport of matter and charge through the oxide film on the material is one of the rate-controlling factors. Straining of the bulk material may affect the transport rates of ionic defects, such as vacancies and interstitials, through the oxide film. The aim of the present work has been to verify the applicability of combined slow strain rate tests (SSRT) and contact electric resistance (CER) measurements to assess the influence of strain on the electric properties of oxide films on AISI 316L stainless steel with or without prior cold work in simulated boiling water reactor (BWR) coolant conditions. The SSRT-CER measurements have been combined with ex situ characterisation of the oxide films after experiments using electron spectroscopy for chemical analysis (ESCA) and scanning electron microscopy (SEM). The results suggest that the effect of strain on the resistance of the oxide films seems to correlate with the effect of the same parameter on the Cr(III) concentration in the inner layer of the oxide. In addition, important differences between the concentration of Ni and Fe in the outer layer formed on stressed and unstressed surface have been observed. Based on the mixed-conduction model for oxide films, an attempt is made to evaluate the effect of straining on the electric properties of the oxide films and to correlate these effects with the changes in film composition and structure.