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The identical two-degrees-of-freedom loudspeaker systems are discussed for synchronization of chaos in this paper. Two methods are used to synchronize two identical chaotic systems with different initial condition: the adaptive control and the Gerschgorin''s theorem. Finally we research the parameter identification for two identical two-degrees-of-freedom loudspeaker systems by adaptive control and random optimization method. [Copyright &y& Elsevier]

The chaos anti-control and synchronization of a two-degrees-of-freedom loudspeaker system are studied in this paper. Anti-control term is added to change state from regular to chaos. The anti-control methods such as addition of a constant force, of a periodic square wave, of a periodic saw tooth wave, of a periodic triangle wave, of a periodic rectified sinusoidal wave and of the x|x| term are used. The results are illustrated by numerical results, i.e. bifurcation diagram and Lyapunov exponents. Next, chaos synchronization of different order system is studied. Two methods are presented to achieve the synchronization: the addition of the coupling terms, the linearization of the error dynamics. The results are illustrated by phase diagram and time response. [Copyright &y& Elsevier]

Cake filtration experiments of suspensions of polystyrene particles, of uniform morphology, through Nuclepore membranes having uniform pores were carried out. The effects of particle properties (size and surface charge), suspension properties (particle concentration and ionic strength), and applied pressure were determined. The results were analyzed in terms of the conventional Darcy-Ruth filtration equation. Plots of resistance versus weight of solids in the cake revealed two distinct regions with a transition occurring early on in the filtration process at a cake thickness of the order of 1 mm. The initial portion has a lower average slope (specific resistance) than that of the second region. It is by only plotting this second region (i.e. ignoring the initial stages of the filtration process) that apparent negative values for the medium resistance are obtained.The specific cake resistance obtained from the slope of the second region, which spans at least 90% of the filtration time, was correlated with particle and dispersion properties. The specific filtration resistance was essentially independent of slurry concentration and of the total applied pressure. Specific cake resistance measured at constant pressure and slurry concentration showed an inverse dependence on ionic strength.

ABSTRACT

Compressibility of cakes is basic to separation of solids from slurries. Cake compression is caused by collapsing, particulate structures in which particles are forced into existing voids. Stresses causing the collapse arise from unbuoyed weight of solids in thickeners, radial acceleration in centrifuges, frictional pressure drop in filters, and mechanical forces in press belts and membrane actuated filters. Compressibility is a function of particle size and shape and the degree of aggregation.Flow through very compressible cakes produces a highly non-uniform structure with a tight skin of low porosity next to the supporting medium. This skin leads to adverse effects in which increasing filter pressure has little effect on flow rate or average porosity. Similarly increasing the squeezing pressure indefinitely in expression has little effect upon the rate of removal of liquid.

Zusammenfassung Wir berichteten über die Behandlung der Hyperthyreosen mit Dioxydiäthylstilben, wobei vor allem der Grundumsatz beachtet wurde. In der Hälfte aller Fälle konnte er günstig beeinflußt werden; in 3 Fällen wurde eine völlige Normalisierung erzielt. Auch andere subjektive und objektive Anzeichen der Besserung (z. B. Gewichtszunahme) konnten beobachtet werden.