Ultrasound homogenizer

Ultrasound homogenizer (e.g., Bandelin sonoplus GM 70, Bandelin, Berlin, Germany). 

Before enzyme measurements, approximately 300-500 pi of demineralized water is added and the mixture is sonicated for 10 s on ice. Depending on the ultrasound homogenizer, the time required may vary slightly. Protein is determined according to Lowry et al. [43]. The final protein content for enzyme measurements is adjusted to approximately 5 mg/ml with demineralized water. 

Ultrasonic treatment can also disrupt milk fat globules, probably through cavitation and other shear and shock effects (Villamiel, 1999). Wu et al. (2001) reported that high amplitude ultrasound homogenization of milk for yogurt manufacture achieved similar effects as conventional homogenization. 

Any system involving a homogeneous liquid in which bubbles are produced is strictly not homogeneous in sonochemistry, however, it is not unusual to deem systems under ultrasound homogeneous. Sonochemical effects generally occur inside the collapsing bubble, where extreme conditions are produced, or at the interface between the cavity and the bulk liquid, where the conditions are far less extreme, or in the bulk liquid immediately surrounding the bubble, where the dominant effects are mechanical in nature. 

Traditional methods of emulsification include high-pressure homogenizers, rotor-stator systems, and ultrasound homogenizers [110, 111], The first two examples employ high mechanical shear rates to produce small droplets of the... 

Homogeneous sonochemistry typically is not a very energy efficient process (although it can be mote efficient than photochemistry), whereas heterogeneous sonochemistry is several orders of magnitude better. Unlike photochemistry, whose energy inefficiency is inherent in the production of photons, ultrasound can be produced with neatly perfect efficiency from electric power. A primary limitation of sonochemistry remains the small fraction... 

Homogeneous Sonochemistry Bond Breaking and Radical Formation. The chemical effect of ultrasound on aqueous solutions have been studied for many years. The primary products are H2O2 there is strong evidence for various high-energy intermediates, including HO2,... 

Figure 2 schematically presents a synthetic strategy for the preparation of the structured catalyst with ME-derived palladium nanoparticles. After the particles formation in a reverse ME [23], the hydrocarbon is evaporated and methanol is added to dissolve a surfactant and flocculate nanoparticles, which are subsequently isolated by centrifugation. Flocculated nanoparticles are redispersed in water by ultrasound giving macroscopically homogeneous solution. This can be used for the incipient wetness impregnation of the support. By varying a water-to-surfactant ratio in the initial ME, catalysts with size-controlled monodispersed nanoparticles may be obtained. 

In 1981, the first report on the sonochemistry of discrete organometallic complexes demonstrated the effect of ultrasound on iron carbonyls in alkane solutions (174). The transition metal carbonyls were chosen for these initial studies because their thermal and photochemical reactivities have been well characterized. The comparison among the thermal, photochemical, and sonochemical reactions of Fe(CO)5 provides an excellent example of the unique chemistry which homogeneous cavitation can... 

Having demonstrated that ultrasound can induce ligand dissociation, the initiation of homogeneous catalysis by ultrasound becomes practical. The... 

Liposphere formulations are prepared by solvent or melt processes. In the melt method, the active agent is dissolved or dispersed in the melted solid carrier (i.e., tristearin or polycaprolactone) and a hot buffer solution is added at once, along with the phospholipid powder. The hot mixture is homogenized for about 2 to 5 min, using a homogenizer or ultrasound probe, after which a uniform emulsion is obtained. The milky formulation is then rapidly cooled down to about 20°C by immersing the formulation flask in a dry ice-acetone bath, while homogenization is continued to yield a uniform dispersion of lipospheres. 

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