A cavitation device and method for using the same is useful for cavitationally treating fluids by generation of hydrodynamic cavitation in the fluid followed by the subsequent collapse of cavitation bubbles. The passage of fluid through slot openings in a cylindrical insert mounted in a housing provides fluid jets in an annular cavity to induce hydrodynamic cavitation of the fluid. Fluid is discharged from the annular cavity into a downstream portion of the housing to collapse cavitation bubbles under static pressure.

The present invention generally relates to the manipulation of fluids using acoustic waves such as surface acoustic waves. In some aspects, one fluid may be introduced into another fluid via application of suitable acoustic waves. For example, a fluid may be added or injected into another fluid by applying acoustic waves where, in the absence of the acoustic waves, the fluid cannot be added or injected, e.g., due to the interface or surface tension between the fluids. Thus, for example, a fluid may be injected into a droplet of another fluid. Other embodiments of the invention are generally directed to systems and methods for making or using such systems, kits involving such systems, or the like.

A method for producing a resin particle dispersion includes: obtaining a phase-inverted emulsion by adding a neutralizer to a resin solution prepared by dissolving a resin having an acid value in an organic solvent to thereby neutralize the resin and then adding an aqueous medium to the resulting resin solution to subject the resin to phase inversion emulsification; and removing the organic solvent from the phase-inverted emulsion. In the course of obtaining the phase-inverted emulsion, a maximum agitation power per unit mass (kg) of the resin when the resin solution containing the aqueous medium added thereto is agitated to perform the phase inversion emulsification is from 0.4 W to 20 W inclusive.

A method is provided for monitoring a flow behavior of mixed components without requiring additional instrumentation or sampling. The method is carried out by determining ratios of the power required to rotate a mixing impeller at different rotational speeds and then comparing the ratios. Characteristics about the mixed components are determined based on differences between the ratios.

The invention relates to a stirred tank reactor for gas-liquid mass transfer in a slurry. The reactor includes a reactor tank (1) having a first volume (V.sub.1), a drive shaft (2) that extends vertically in the reactor tank, a motor (3) for rotating the drive shaft (2), a main impeller (4) which is a downward pumping axial flow impeller attached to the drive shaft (2) to create a main flow pattern in the reactor tank, and a gas inlet (5) arranged to supply gas into the reactor tank (1) to be dispersed to the liquid. The reactor includes a mechanical gas sparging apparatus (6) comprising a dispersion chamber (7) having a second volume (V.sub.2) which is substantially smaller than the first volume (V.sub.1) of the reactor tank (1), the dispersion chamber being arranged coaxial with the drive shaft (2), and the gas inlet (5) being arranged to feed gas into the dispersion chamber (7), and mixing means (8, 9, 10, 11, 12) arranged within the dispersion chamber (7) for mixing the gas into liquid by dispersing the gas to fine bubbles before the bubbles enter the main flow pattern. The mixing power per unit volume inside the dispersion chamber (7) is significantly larger than the mixing power elsewhere in the reactor.

A method is provided for monitoring a flow behavior of mixed components without requiring additional instrumentation or sampling. The method is carried out by determining ratios of the power required to rotate a mixing impeller at different rotational speeds and then comparing the ratios. Characteristics about the mixed components are determined based on differences between the ratios.

A cavitation device and method for using the same is useful for cavitationally treating fluids by generation of hydrodynamic cavitation in the fluid followed by the subsequent collapse of cavitation bubbles. The passage of fluid through slot openings in a cylindrical insert mounted in a housing provides fluid jets in an annular cavity to induce hydrodynamic cavitation of the fluid. Fluid is discharged from the annular cavity into a downstream portion of the housing to collapse cavitation bubbles under static pressure.

A method is provided for monitoring a flow behavior of mixed components without requiring additional instrumentation or sampling. The method is carried out by determining ratios of the power required to rotate a mixing impeller at different rotational speeds and then comparing the ratios. Characteristics about the mixed components are determined based on differences between the ratios.

The present invention generally relates to the manipulation of fluids using acoustic waves such as surface acoustic waves. In some aspects, one fluid may be introduced into another fluid via application of suitable acoustic waves. For example, a fluid may be added or injected into another fluid by applying acoustic waves where, in the absence of the acoustic waves, the fluid cannot be added or injected, e.g., due to the interface or surface tension between the fluids. Thus, for example, a fluid may be injected into a droplet of another fluid. Other embodiments of the invention are generally directed to systems and methods for making or using such systems, kits involving such systems, or the like.

Bioreactors are provided that include a vessel and a jet mixer disposed in the vessel. Methods that utilize the bioreactors are provided, involving placing a microorganism or cells and a fluid medium in the bioreactor.