Synthesis and polymerization of p-bromomethylstyrene and p-lodomethylstyrene

Summary Synthesis of p-bromomethylstyrene (3) and p-iodome-thylstyrene (4) is reported. 3 was obtained by the bromomethylation of 2-phenylethyl bromide followed by dehydrobromination of the resultant p-(2-bromoethyl) benzyl bromide (2) with t-BuOK, as well as by cleaving p-vinyl-benzyl methanosulfonate with LiBr in the presence of 18--crown-6. 4 was obtained from p-chloromethylstyrene (1) via the Finkelstein reaction. 3 was polymerized successfully in the presence of free-radical initiators, but 4 was found to be too unstable to give a well-defined polymer.     

Process of extrusion in the unit of special design

Extrusion of paste materials is a means of processing powder materials to a granulated form. A powder material is mixed with a liquid and transformed to the form of paste. The paste has to have the appropriate flow properties to be able to be extruded. This is very important especially in the area of reduction between the barrel and die. There is the place where the paste has to deform itself and to flow into the holes of die that have a smaller cross section than is in the barrel. It is the zone where the rheology properties of paste and its speed have the biggest influence on the extrusion pressure. It can even happen that the paste can be dewatered under the pressure gradient in this place. If the rotor with blades is situated in this zone it has a positive influence on the process of extrusion. This element has an influence on the rate of shear strain and decreasing of the apparent viscosity with a following drop in the extrusion pressure. This paper describes research of the process of extrusion in equipment with separated drives of the screw and a rotor that is placed in the input zone in the hole of matrix. First influence of the operating speeds of screw and rotor on extrusion pressure is studied here, then it is compared with the torque that is needed for the drive of the rotor. According to the results it is evident that the extrusion pressure increases with the accrual of the speed of flowing paste and decreases with the increase of the rotors operating speed. The influence of flowing paste on the torque is complicated. There is an interval where the torque goes up and then an interval in which the torque decreases. The results of experiments confirmed that the rotor has a positive influence on the process of extrusion.We would like to thank the Grant Agency of the Slovak Republic for supporting our research work performed in the frame of Grant Project No.1/8092/01.     

On Duality between Quantum Maps and Quantum States

We investigate the space of quantum operations, as well as the larger space of maps which are positive, but not completely positive. A constructive criterion for decomposability is presented. A certain class of unistochastic operations, determined by unitary matrices of extended dimensionality, is defined and analyzed. Using the concept of the dynamical matrix and the Jamiokowski isomorphism we explore the relation between the set of quantum operations (dynamics) and the set of density matrices acting on an extended Hilbert space (kinematics). An analogous relation is established between the classical maps and an extended space of the discrete probability distributions.     

Distributed OSGi built over message‐oriented middleware

This paper describes key aspects of remote service invocation in federations of OSGi containers. It refers to the OSGi Remote Service Admin specification and describes its efficient implementation over message‐oriented middleware. Scalability problems of several different approaches to implementation are identified, and a solution in a form of innovative Remote Service Admin model extension is proposed. The extension, named On‐demand Remote Service Admin, is analyzed and validated in the context of a motivating scenario. Validation includes performance and scalability evaluation, which confirms that all assumed requirements have been satisfied by the constructed prototype. Finally, the presented research is compared with related works. Copyright © 2011 John Wiley & Sons, Ltd.     

On decentralised control of non-linear interconnected systems

The asymptotic stabilisation problem of a class of large-scale interconnected systems is considered, where the non-linear interconnections between subsystems satisfy quadratic constraints that are functions of the whole system's state vector. A decentralised combined observer-controller compensator is proposed and analysed, where the subsystems’ state vectors are estimated using local sliding mode observers. The closed-loop system driven by the proposed decentralised compensator is guaranteed to be asymptotically stable subject to two conditions that are easily verifiable. Simulation results illustrate the effectiveness of the proposed decentralised combined observer-controller compensator.     

Determination of Thermal-Diffusivity Dependence on Temperature of Transparent Samples by Thermal Wave Method

The use of a typical measuring cryostat with a standard temperature controller was proposed for investigation of the temperature dependence of the thermal diffusivity of transparent samples. The basic idea is to use the cryostat heater to control the mean sample temperature and to generate the thermal wave in it, simultaneously. Because of the relatively high thermal inertia of the system, the measurements are carried out at frequencies not exceeding 50 mHz. The periodic temperature disturbance in the sample was detected optically by the use of the mirage effect. The proposed method was used for determination of the thermal diffusivity of yttrium aluminum garnet single crystals in a temperature range from 20 °C to 200 °C.     

Some Considerations on Branching Areas of Time

In this paper we show that properties of non-linear time structures have not been studied enough. Axioms forcing the existence of a branching point in a branching area of a structure are presented for various classes of structures. We show also that the classical Dedekind continuity axiom does not work well in non-linear structures and we suggest stronger versions. Finally, some interdependencies between the axioms presented are proved.     

On the modelling of heat conduction problem in laminated bodies

Summary The paper deals with the heat conduction modelling problem for micro-periodic composites. The models proposed there take into account certain micromorphic effects resulting from the fine periodic structure of the body. The governing equations describing heatfluxes and temperature distributions in these composites in the nonlinear as well as linear cases have been derived. Two examples of the application of the presented models are detailed.With 4 Figures