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Abstract

At the turn of October 1985, the abundance of breeding Adelie penguins was estimated at the Hope Bay oasis on the Antarctic Peninsula and on Seymour Island. In the Hope Bay rookery, 123850 pairs of penguins were recorded, beginning their breeding at the end of October. Data so far obtained indicate a continuous increase in the number of birds sat this rookery. On the other hand, the Seymour Island colony consisted of 21954 pairs of Adélie penguins. Clear differences in the geomorphological structure of areas occupied by penguins in those two places are discussed. No gentoo penguins were detected in either of the colonies.
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Abstract

The axisymmetric problem of acoustic impedance of a vibrating annular piston embedded into a flat rigid baffle concentrically around a semi-infinite rigid cylindrical circular baffle has been undertaken in this study. The Helmholtz equation has been solved. The Green’s function valid for the zone considered has been used for this purpose. The influence of the semi-infinite cylindrical baffle on the piston’s acoustic impedance has been investigated. The acoustic impedance has been presented in both forms: integral and asymptotic, both valid for the steady harmonic vibrations. Additionally, the acoustic impedances of the piston with and without the cylindrical baffle have been compared to one another. In the case without the cylindrical baffle some earlier results have been used
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Abstract

Steady-state characteristics of a catalytic fluidised bed reactor and its dynamical consequences are analyzed. The occurrence of an untypical steady-state structure manifesting in a form of multiple isolas is described. A two-phase bubbling bed model is used for a quantitative description of the bed of catalyst. The influence of heat exchange intensity and a fluidisation ratio onto the generation of isolated solution branches is presented for two kinetic schemes. Dynamical consequences of the coexistence of such untypical branches of steady states are presented. The impact of linear growth of the fluidisation ratio and step change of the cooling medium temperature onto the desired product yield is analyzed. The results presented in this study confirm that the identification of a region of the occurrence of multiple isolas is important due to their strong impact both on the process start-up and its control.
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