ABSTRACT
Diffusion processes are among the most important technical operations in various industries, especially chemical, pharmaceutical, and food production. In the diffusion model, it is assumed that viscous forces and permeability barriers within the microstructure of the biological material prevent coherent velocity ªow of water, whose moisture movement occurs by random molecular diffusive motion. Cellular material approximates to the diffusive model because the cell membranes and cell walls act as permeability barriers, preventing coherent ªuid ªow. The complicated system of tissue, cell and its components, and substructural division into cell parts results from the evolution of cellular organisms. Cells are able to exchange nutrients and molecules with their environment through the cell membrane, which encloses
4.1 Introduction .................................................................................................. 123 4.2 Diffusion .......................................................................................................124 4.3 Properties of Ultrasounds ............................................................................. 126 4.4 Ultrasound and Cavitation ............................................................................ 128 4.5 Applications of Ultrasounds ......................................................................... 129
4.5.1 Extraction .......................................................................................... 129 4.5.1.1 Oil Extraction ..................................................................... 130 4.5.1.2 Sugar Extraction ................................................................ 131 4.5.1.3 Extraction of Different Organic Compounds .................... 131
4.5.2 Crystallization and Dissolution ........................................................ 134 4.5.3 Salting and Curing ............................................................................ 134 4.5.4 Drying ............................................................................................... 135 4.5.5 Membrane Processes ........................................................................ 136 4.5.6 Other Mass Transfer Processes ......................................................... 137
4.6 Ultrasonic Equipment ................................................................................... 137 4.7 Safety of Ultrasound Applications................................................................ 139 4.8 Conclusion .................................................................................................... 140 References .............................................................................................................. 141
cell materials. The process rate is determined by the physical properties and chemical composition of the system (Brennan 2006; Sun 2006).
