a  facile  effective  stirring  aging  at  room  temperature  prior  to  conventional  hydrothermal treatment was employed in the template-free synthesis of micro- and nano-crystalline sodalites with  two  different  initial  gel  compositions.  the  effect  of  initial  si/al  molar  ratio,  naoh concentration and stirring aging time were investigated on the morphology and particle size of the...

The effect of stirring in an inhomogeneous oscillatory medium is investigated. We show that the stirring rate can control the macroscopic behavior of the system producing collective oscillations (synchronization) or complete quenching of the oscillations (oscillator death). We interpret the homogenization rate due to mixing as a measure of global coupling and compare the phase diagrams of stirr...

Stirring largely eliminated the greater effectiveness of Carbowax 6000 compared to mannitol in reducing cucumber (Cucumis sativus L.) hypocotyl section elongation. Stirring increased elongation in water but reduced elongation in growth regulator solution. Shrinkage of cells without plasmolysis in hypertonic Carbowax solutions indicates that Carbowax 6000 did not penetrate cell walls. Sections p...

In this paper a particle-base model is used to visualize results of the magnetohydrodynamics (MHD) phenomena related to electromagnetic levitation (EML) and magnetic stirring. Using the theoretical model presented in Part I, a numerical algorithm for fluid flow simulation has been described. To struggle out the local dynamics, the position and velocity of each particle is visualized and the int...

We prove the existence of invariant curves for a T – periodic Hamiltonian system which models a fluid stirring in a cylindrical tank, when T is small and the assigned stirring protocol is piecewise constant. Furthermore, using the Numerical Analysis of the Fundamental Frequency of Laskar, we investigate numerically the break down of invariant curves as T increases and we give a quantitative est...

We stir with a focused laser beam a Bose-Einstein condensate of 87 Rb atoms confined in a magnetic trap. We observe the formation of a single vortex for a stirring frequency exceeding a critical value. At larger rotation frequencies we produce states of the condensate for which up to eleven vortices are simultaneously present. We present measurements of the decay of a vortex array once the stir...

This paper presents a microfluidic mixer that uses acoustic stirring created by ultrasonic waves. The ultrasound is introduced into the channel by integrated piezoelectric transducers. The transducers are made of a zinc oxide thin film, which is deposited on the bottom surface of a quartz substrate. The poly(dimethylsiloxane) channel is aligned to the transducers on the top surface of the subst...

The main objective of this study was to evaluate the influence of the formulation and process parameters on PLGA microparticles containing a practically insoluble model drug (ibuprofen) prepared by the o/w solvent evaporation method. Multivariate data analysis was used. The effects of altered stirring speed of a mechanical stirrer (600, 1000 rpm), emulsifier concentrations (PVA concentration 0....

We performed the biotransformation of ferulic acid to vanillin using Bacillus subtilis (B. subtilis) in the stirring packed-bed reactors filled with carbon fiber textiles (CFT). Scanning electron microscope (SEM), HPLC, qRT-PCR and ATP assay indicated that vanillin biotransformation is tightly related to cell growth, cellar activity and the extent of biofilm formation. The biotransformation was...

Simultaneous application of UV light and ultrasonic irradiation to a reaction mixture containing 1-iodocyclohexene is reported. The irradiation of 1-iodocyclohexene in methanol was carried out with or without addition of zinc. The effect of ultrasound or mechanical stirring on this solid-liquid system was also compared. The irradiation of 1-iodocyclohexene in methanol in the presence of zinc in...