Large-scale multimedia content delivery over optical networks for interactive TV services

iTVP is a system built for delivery of live TV programming, video-on-demand and audio-on-demand with interactive access over IP networks. It has a nationwide range and is designed to provide service to a high number of concurrent users. Hence, scalability is one of the most important issues. In this paper we described how scalability is achieved in a two-level hierarchical architecture of the delivery system. We present the principles of content caching mechanisms and the management of the resulting distributed content repository. The system is implemented and currently operates in a test installation. Although the range of the test system operations is limited, as far as the number of users and the size of the content repository is concerned, the experience gained with iTVP so far provides an insight into the expected prototype performance. We present a system performance evaluation and describe the experience gained during the iGrid demonstration.     

Estimation of complex multimodal motion: an approach based on robust statistics and Hough transform

An application of robust statistics in a Hough transform based motion estimation approach is presented. The algorithm is developed and experiments are performed, proving its superior performance in terms of estimate accuracy, convergence, robustness and better segmentation. Comparative results with standard methods are also included.     

Oxidant--nitric oxide signalling mechanisms in vascular tissue

Nitric oxide has several signalling mechanisms that can potentially control force generation by vascular smooth muscle. Some of these mechanisms include the stimulation of cGMP production by the soluble heme-containing form of guanylate cyclase (sGC), inhibition of mitochondrial respiration, and the modulation of vasoactive mediator release by the endothelium. Reactive O2 species (ROS) can also regulate force generation by vascular smooth muscle through mechanisms including the stimulation of production of vasoactive prostaglandins, the stimulation of sGC by catalase-mediated metabolism of H2O2 and inhibition of sGC activation by superoxide, the activation of protein kinase C, and the modulation of mediator release from the endothelium. Interactions between NO and ROS signalling mechanisms result in additional processes which modulate vascular force generation. For example, NO-elicited stimulation of sGC can be attenuated by superoxide, and this results in the formation of peroxynitrite (ONOO-). However, high levels of NO result in a ONOO- and thiol dependent formation of a species which regenerates NO in a time-dependent manner. It appears that NO inhibits catalase through an O2 and superoxide dependent process which results in inhibition of relaxation mediated by H2O2-elicited stimulation of sGC. Furthermore, evidence exists suggesting additional signalling mechanisms resulting from interactions between regulatory systems involving NO and ROS which appear to be important in control of vascular force generation in pathophysiological states.     

Application of Ozone in Textile Wastewater Treatment

Textile wastewaters are known to be highly resistant to biodegradation under both natural and wastewater treatment plant conditions. However, ozonation can be used to increase the biodegradability of the biologically resistant compounds. The combined method of ozonation and subsequent biodegradation of both synthetic and real textile wastes was explored in laboratory-scale studies. Two kinds of industrial wastes were simulated for effluents from dyehouse and washing machines. Upon determining the ozonation conditions of synthetic wastes, the real industrial wastes were investigated. The real textile wastewater was taken from textile factories, located in ód? , Poland, from subsequent stages of textile processing; dyeing, washing, rinsing and from an equalizer tank. Ozonation was carried out in a lab-scale bubble column sparged reactor, while the biological degradation proceeded in a trickle bed biofilter.     

Model of Desulphurization of Steel Melts in Ladles – Deoxidation and Slag Formers Calculation

The authors present their own model applicable for effective desulphurization of steel by ladle treatment. The model is based on a thermodynamic approach (equilibrium data) and technological data (correction factors). It consists of two parts. In the first part the authors present the formulae derived for estimation of the additions of deoxidation agents which ensure sufficiently low oxygen level prior to the desulphurization process, while the other part gives a qualitative and quantitative selection of slag formers to achieve low final levels of sulphur in steel. For the deoxidation process two variants were considered: (i) with Al only (for low silicon steels) or (ii) Al‐Si (for silicon steels) as deoxidizers. For the desulphurization process three variants were assumed as to ladle slag composition: (i) slag consisting of a fraction of furnace slag, lime addition and deoxidation products, (ii) slag made of synthetic CaO–Al₂O₃ and (iii) slag based on lime and fluorspar. The model formulae for desulphurization were derived using the sulphide capacity concept which relies on the optical basicity. In addition, rough estimates of the slag liquidus temperatures are given. A numeric example of the model application and the model algorithm (appendix) are enclosed.     

Integrated design of prestressed cast-iron pressure vessel and passive heat removal system for the reactor cell of a 200 MWth modular reactor

For a modular reactor of 200 MW thermal output an inactive after heat removal system has been designed. It consists of a prestressed cast iron pressure vessel with the surrounding reactor cell. Integrated in the cast iron profiles of the reactor cell is a redundant water cooling system based on natural convection. Air cooling towers are provided to cool the water down to ambient temperature. The cooling system covers a wide range of possible wall temperatures without significant changes in water temperature. The structures of the reactor pressure vessel and the cell, their assembly and some results of the engineering work done up to now are described in this paper.     

The electrochemical corrosion of amorphous Ni36Fe32Cr14P12B6 alloy (Metglass 2826A)

The resistance to electrochemical corrosion of alloy Meglas 2826A in the amorphous state and after crystallization was studied in non-aqueous and aqueous chloride solutions. The results were compared with the data obtained for alloy steels. Amorphous alloy Metglas 2826A was found to exhibit very high corrosion resistance, greatly exceeding that of high-alloy steels. After crystallization of this alloy, its corrosion resistance dropped to the level characteristic of alloy steels. The high stability of the passive film on the amorphous material was attributed to the homogeneity of alloy structure.     

Gamow-Teller matrix elements for two-neutrino double beta decay within a second quasi-random-phase approximation

The ascendency of the cerebral cortex in mammals naturally raises questions about the role of the archetypal subcortical centers we share in common with other phyla. Here we report a situation in which an ancient oculomotor control center, the nucleus of the optic tract, is not so much dominated by the cerebral cortex as served by it. We suggest that the organization of cortical output to subcortical centers may be helpful in understanding the function of the cerebral cortex.     

The influence of anode passivation on the quality and structure of cathode copper

The paper discusses periodic passivation and autodepassivation of anodes and the effect of these processes on the quality and structure of cathodic copper. Quality inspection of cathodic copper and the history of its formation by means of the anode etching method was described.