The present work investigates the acoustical absorption and scattering cross-sections of spherical bubble clouds subject to harmonic far field pressure excitation. Bubble dynamics effects and energy dissipation due to viscosity, heat transfer, liquid compressibility and relative motion of the two phases are included. The equations of motion for the average flow and for the bubble radius are lin...

Microfluidic technology offers capabilities for the precise handling of small fluid volumes dispersed as droplets. To fully exploit this potential requires simultaneous generation of multiple size droplets. We demonstrate two methods for passively breaking larger drops into precisely controlled daughter drops using pressure-driven flow in simple microfluidic configurations: (i) a T junction and...

the purpose of this study was to prepare and characterize nimodipine loaded microspheres using ethyl cellulose (ec) as a carrier polymer through an emulsion solvent evaporation method. these evaluations characterized the pattern of drug release from prepared microspheres. nimodipin loaded microspheres were prepared using an emulsification solvent evaporation method. the effect of process variab...

Holdup was measured at various frequencies, amplitudes, continuous and dispersed phase flow rates for binary systems in a pulsed plate column capable of providing samples at various heights. The binary systems was so selected as to cover a wide spectrum of interfacial tensions. Dispersed phase holdup was found to increase with height in a logarithmic fashion at conditions away from the flooding...

Conventional modeling of two-phase dilute suspensions is achieved with the Euler equations for the gas phase and gas dynamics pressureless equations for the dispersed phase, the two systems being coupled by various relaxation terms. The gas phase equations form a hyperbolic system but the particle phase corresponds to a hyperbolic degenerated one. Numerical difficulties are thus present when de...

A Rotary Disc Contactor with inner diameter of 9.1cm and maximum operating height of 40cm has been used to investigate break up phenomenon. Water-Toluene, Water as continuous phase and Toluene as dispersed phase, was selected as chemical system in the experiments. The mentioned chemical system has high interfacial tension so it was possible to form big drops which permit accurate investigation ...

We demonstrate that polyelectrolyte (PE) multilayer thin films deposited on patterned posts with incredibly large numbers of bilayers, which would not be possible with the conventional Layer-by-Layer (LbL) deposition methods, can be obtained in a short process time using alternating polyelectrolyte droplets generated in a microfluidic channel, representing a significant advantage over the conve...

Control of fluid dynamics at the micrometer scale is essential to emulsion science and materials design, which is ubiquitous in everyday life and is frequently encountered in industrial applications. Most studies on multiphase flow focus on oil-water systems with substantial interfacial tension. Advances in microfluidics have enabled the study of multiphase flow with more complex dynamics. Here...

This paper reports a technique for temperature-induced merging of droplets in a microchannel. The multiphase system consists of water droplet and oil as the dispersed phase and the carrying continuous phase. A resistive heater provides heating in a rectangular merging chamber. The temperature of the chamber is controlled by the voltage applied to the heater. The merging process of two neighbori...