Processing ultrasound / ultrasonic

Schlaberg, H.I., Yang, M., and Hoyle, B.S. (1997) Ultrasound reflection tomography for industrial processes. 17th Ultrasonics International Conference (U1 97), 1997, Delft. 

There are at present only a few commercial applications of ultrasound in the plastics industry. The best knovm is probably the welding of thermoplastics, a process which now lends itself readily to automation. In common with the welding of metals, the ultrasonic welding of plastics is primarily a hot stage. In the process ultrasound is applied to two layers of plastic, heat is generated at the interface causing the material... 

The colloidal properties of emulsions are responsible for the quality of many foods. Ultrasound is sensitive to most of the properties of interest and can be used as both a research and a process-control tool by food scientists. As a research tool, ultrasonic measurements are particularly powerfid as they can be used to generate information not readily available by other methods - importantly, physical state, particle size, concentration, and flocculation in concentrated and optically opaque emulsions. In a process environment, ultrasonic measurements can be effected noninvasively in process lines and are therefore compatible with the stringent hygiene and cleaning requirements of food production. 

Recently, a novel continuous process has been developed for devulcanization of rubbers as a suitable way to recycle used tires and waste rubbers [83-119]. This technology is based on the use of high-power ultrasounds. The ultrasonic waves of certain levels, in the presence of pressure and heat, can quickly break up the three-dimensional network in crosslinked rubber. The process of ultrasonic devulcanization is very fast, simple, efficient, and solvent and chemical free. Devulcanization occurs at the order of a second and may... 

Fuente-Blanco, S., Riera-Franco de Sarabia, E., Acosta-Aparicio, V. M., Blanco-Bianco, A., Gallego-Juarez, J. A., 2006. Food drying process by power ultrasound. Ultrasonics 44 e523-e527. 

Gallego-Juarez, J.A. Some applications of air-borne power ultrasound to food processing, in Ultrasonics in Food Processing (Povey, M.J.W., Mason, T.J., eds.), Thomson Science, London, 1998, p 127. 

Flocculation can also be detected directly using ultrasonic methods. During the flocculation process the ultrasonic properties change significantly and are not consistent with theory for spherical drop scattering. This is because a network has been formed, and at present there is no suitable theory to describe the propagation of ultrasound through such a structure. 

The weld depths penetration for gold-nickel alloy and tantalum cylinders have been well controlled by an entirely contactless ultrasound method. Nevertheless, the development of signal and image processing will allow to increase the resolution of the ultrasonic images. Moreover, in order to be able to size quite well the lacks of weld penetration, the simulation of the interaction beam-defect is presently developed in our laboratory. 

Unlike vibration monitoring, ultrasonics monitors the higher frequencies, i.e. ultrasound, produced by unique dynamics in process systems or machines. The normal monitoring range for vibration analysis is from less than 1 Hertz to 20,000 Hertz. Ultrasonics techniques monitor the frequency range between 20,000 and 100 kHz. 

Yang, M. et al. (1999) Real-time ultrasound process tomography for two-phase flow imaging using a reduced number of transducers. IEEE Trans. Ultrason. Ferroelectr. Freq. 

Some of the reports are as follows. Mizukoshi et al. [31] reported ultrasound assisted reduction processes of Pt(IV) ions in the presence of anionic, cationic and non-ionic surfactant. They found that radicals formed from the reaction of the surfactants with primary radicals sonolysis of water and direct thermal decomposition of surfactants during collapsing of cavities contribute to reduction of metal ions. Fujimoto et al. [32] reported metal and alloy nanoparticles of Au, Pd and ft, and Mn02 prepared by reduction method in presence of surfactant and sonication environment. They found that surfactant shows stabilization of metal particles and has impact on narrow particle size distribution during sonication process. Abbas et al. [33] carried out the effects of different operational parameters in sodium chloride sonocrystallisation, namely temperature, ultrasonic power and concentration sodium. They found that the sonocrystallization is effective method for preparation of small NaCl crystals for pharmaceutical aerosol preparation. The crystal growth then occurs in supersaturated solution. Mersmann et al. (2001) [21] and Guo et al. [34] reported that the relative supersaturation in reactive crystallization is decisive for the crystal size and depends on the following factors. 

Breitbach M, Bathen D (2001) Influence of ultrasound on adsorption processes. Ultrason Sonochem 8(3) 277-283... 

Ultrasonic irradiation has been shown in laboratory studies [73] to increase dye exhaustion, enabling salt levels to be reduced. However, it seems doubtful whether the higher effectiveness is sufficient to merit development to overcome the problems involved in scaling-up the ultrasonic equipment to bulk-scale processing. For example, in one experiment using 5% salt at 65 °C, ultrasound treatment increased the dye exhaustion from 77% to 82%. 

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