Evaluating the water chemistry in the primary circuit and the effect of chemical decontamination of the heat exchanger tubes performed by the AP-CITROX procedure at Paks NPP (Hungary), a project dealing with the comprehensive investigation of the general corrosion state of the steam generators (SGs) has been initiated. Owing to the fact that there is no investigation method available for the in-situ monitoring of the inner surfaces of heat exchanger tubes, a research program based on sampling as well as on ex-situ electrochemical and surface analytical measurements were developed and elaborated. In the time period of 2000-2008 - within the frame of the above project - 45 stainless steel specimens, cut out from various locations of the steam generators of the Paks NPP were investigated. Besides to the corrosion characteristics (corrosion rate, thickness and chemical composition of the protective oxide-layer) surface properties (morphology, chemical and phase compositions) of the passive layer formed on the inner surface of above heat exchanger tubes were studied, too. The passivity of the inside surface of the stainless steel specimens was measured by voltammetry, the morphology, chemical and phase compositions of the oxide layer formed on the surface were analyzed by SEM-EDX, XRD and CEMS methods. The great number of experimental results allowed us to develop an electronic database which involves the results of the above corrosion experiments, and also some special characteristics of the tubes (e.g. location in the SGs, surface pretreatment by decontamination, if any, etc). Evaluating the main relations among these parameters may contribute to the identification of important processes affecting the corrosion state of steam generators, and highly decisive concerning a life time prolongation project of VVER-type nuclear reactors. In the present work we provide a brief overview on these experiments, some characteristic results, the database developed, as well as some novel findings.

Molecular beam epitaxially grown fullerene layers are investigated with the help of image processing. The layered structures are studied in morphological respect. The individual layer morphologies are derived from the atomic force microscopy picture of the surface. The pattern morphology of the certain layers is analysed by box counting method. The surface morphology shows fractal behaviour. The pattern of each layer shows different dimension. The actual dimension depends on the actual distance of the layer from the substrate. The change of the dimension is attributed to the change of the binding behaviour. The topology of the surface is also studied using participation ratio and structural entropy calculations. © 2009 IEEE.

Modeling of the deformational force and absorbed energy plays a very important role in different fields of vehicle engineering. The usually applied FEM based methods give good approximations, but they have extremely large computational complexity. On the other hand there exist simple force models, but they not approximate well in details the real data. The aim of this paper is to introduce a force model for vehicle deformation, which is able to describe the real process and have acceptable complexity. ©2009IEEE.

This paper deals with the numerical analysis of the Problem No. 32 of the TEAM Workshops. This is a three-limbed ferromagnetic core with pick up coils, which is a test bench for validation of numerical analysis with hysteresis. The numerical procedure is based on the magnetic field computation taking the hysteresis into account. The scalar Preisach model is integrated into a finite element analysis. The hysteretic nonlinearity is handled by the fixed point iterative technique. The results are validated by comparison with the experiments.

Several optimalization algorithms have been proposed for the solution of the basic network flow algorithms, such as the minimal and the multiterminal minimal path of a network having cost (distance) function, maximal flow of a capacitated network. In this paper we present these algorithms in a special network in which on the edges a gain function is given. On the edge (x,y) of the network a t(x,y) transportation cost is defined. In the course of the transportation on the edge (x,y) the goods loose a part of there weight. If one unit of goods is transported from point x to point y then k(x,y) unite of goods arrive at point y, where 0 Show more

Open Access: Yes

DOI: 10.1007/978-3-642-03737-5_32