Formation of the structure of gas-liquid, food dispersion non-equilibrium liquid systems in conditions of hydrodynamic and acoustic cavitation

The present article illustrates the principles of the transition from macro static equilibrium to the equilibrium of micro static volume of liquid dispersion systems under conditions of the combination of two types of cavitation actions. In the process of food dispersion systems production, a non-equilibrium state is created. Properties of disperse systems are explained on the example of invert syrup. In static conditions were determined the principles of formation of aggregates: from sucrose molecules at the stage of sugar dissolution to formation of voids and gas-phase bubbles. Conditions of creation of the dynamic non-equilibrium state of syrup by combining hydrodynamic and acoustic cavitation are taken into consideration. The character of bubble state transformation in conditions of geometry flow in gas-liquid systems and sound oscillations excitation in them is shown. After the collapse of bubbles in the gas phase the nature of the conversion of highly concentrated gas-liquid systems is also represented. That was the determining factor in the formation of materials of new types. The practical output of the present work was the production of products in the conditions of combined cavitation effects.

Behaviour of the western king prawn, Penaeus latisulcatus Kishinouye: effect of food dispersion and crowding

In aquacultural projects, crowding of prawns may adversely influence their growth and survival. In this paper, the behaviour of western king prawns, Penaeus latisulcatus, was investigated in tanks. Six forms of behaviour were identified. Prawns were exclusively nocturnal in their active behaviour. Males and females showed no significant difference in the mean time spent in various behaviours. Feeding efficiency increased as food became more dispersed over the tank floor. Behaviours leading to less efficient feeding increased with increased density, but less severely so if food was evenly dispersed than if food was presented at a point source.