Physico-chemical studies of polymeric carriers

Summary Fractionation procedure on copolymer of N-vinylpyrrolidone and maleic anhydride has been elaborated using water/acetone solvent/nonsolvent system. Viscosity and molecular weight measurements of the fractions were carried out in acidic aqueous medium at 25 °C. The relationship between the intrinsic viscosity and the molecular mass []_c = K·M was obtained at pH = 2.1.     

Did Frege Believe Frege's Principle?

In this essay I will consider two theses that are associated with Frege,and will investigate the extent to which Frege really believed them.Much of what I have to say will come as no surprise to scholars of thehistorical Frege. But Frege is not only a historical figure; he alsooccupies a site on the philosophical landscape that has allowed hisdoctrines to seep into the subconscious water table. And scholars in a widevariety of different scholarly establishments then sip from thesedoctrines. I believe that some Frege-interested philosophers at various ofthese establishments might find my conclusions surprising.Some of these philosophical establishments have arisen from an educationalmilieu in which Frege is associated with some specific doctrine at theexpense of not even being aware of other milieux where other specificdoctrines are given sole prominence. The two theses which I will discussillustrate this point. Each of them is called Frege's Principle, but byphilosophers from different milieux. By calling them milieux I do not want to convey the idea that they are each located at some specificsocio-politico-geographico-temporal location. Rather, it is a matter oftheir each being located at different places on the intellectuallandscape. For this reason one might (and I sometimes will) call them(interpretative) traditions.     

Verification of RANS solvers with manufactured solutions

This paper discusses code verification of Reynolds-Averaged Navier Stokes (RANS) solvers with the method of manufactured solutions (MMS). Examples of manufactured solutions (MSs) for a two-dimensional, steady, wall-bounded, incompressible, turbulent flow are presented including the specification of the turbulence quantities incorporated in several popular eddy-viscosity turbulence models. A wall-function approach for the MMS is also described. The flexiblity and usefulness of the MS is illustrated with calculations performed in three different exercises: the calculation of the flow field using the manufactured eddy-viscosity; the calculation of the eddy-viscosity using the manufactured velocity field; the calculation of the complete flow field coupling flow and turbulence variables. The results show that the numerical performance of the flow solvers is model dependent and that the solution of the complete problem may exhibit different orders of accuracy than in the exercises with no coupling between the flow and turbulence variables.     

AN APPROACH TOWARD CONSISTENCY DEGREES OF FUZZY THEORIES

In fuzzy logic-in wider, but also in narrow sense-the problem of consistency has been discussed more or less occasionally from different points of view. Up to now, however, it has usually not been taken as really important. This may be partly caused by a rather restricted understanding of what is to be meant by consistency or inconsistency in fuzzy logic in the wider sense-e.g. in fuzzy control as one of the main applicational fields of fuzzy logic.

In this paper we deal with fuzzy theories in the realm of the fuzzy logic in narrow sense. Based on the fact that usually an "interactive", r-norm based conjunction is considered together with the min-based conjunction one has in a natural way two different consistency condition. We look here at the weaker one.     

Knowledge base specification to automate the fluid critical point of fluids

In this paper an analytical procedure implemented to structure the knowledge required by an expert system applied for controlling a chemical process is described. The analytical approach is based on L ifecycle of Systems and on Task Model approaches. It was validated with an experimental procedure related to the determination of the critical point of pure fluids (CO₂, N₂O, SF₆) and mixtures of low concentration (CO₂-limonene). For the implementation of the control system an expert system shell (CHRONOS?) was used.     

Double-loop-iterative-tracking-algorithm-based direct coordination for hierarchical steady-state control of interconnected systems

An alternative hierarchical optimization algorithm obtained by combining a double-loop iterative strategy with an efficient coordination task is proposed. The new algorithm derived from the tracking method (Sidaoui et al. 1989, 1991) is applicable to non-convex problems and has the advantage of giving a better rate of convergence. Simulation results are given and compared with the original algorithm, indicating the superiority of the new approach for the example considered.