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Showing 1 to 20 of 74 for “"microbubble"”.
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Microbubble cell actuator
… release them. The release mechanism uses a vapor microbubble as a means of volume expansion to create a jet of fluid that ejects a particle. The theory, design, and testing are described, and successful operation of the device is demonstrated. Applications and suggestions for future work are …
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Quantifying microbubble streaming and its applications
… method involves the use of acoustically excited microbubbles. For ease of manufacture and flow control, setups have largely focused on microbubbles of semi-cylindrical shape, attached to a wall of the microchannel. The application of an ultrasound field drives oscillations of the bubble …
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A numerical study on microbubble mixer
This text comprises a numerical study of the mixing performance on the micromixer, a device which actuates steady streaming by semi-cylindrical sessile bubble oscillations. The mixer's capability of producing chaotic mixing is confirmed and a numerical simulation that is in good agreement with the …
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Surface chemical aspects of microbubble flotation
In order to demonstrate the ability of microbubble flotation to superclean coal to ash levels of less than 2%, several Eastern U. S. coals have been tested. The results show that the process is capable of producing superclean coal with improved recovery as compared to the conventional flotation …
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Quantifying particle sorting in microbubble streaming flows
… by an ultrasonically driven semicylindrical microbubble can be combined with a Poiseuille flow to achieve tunable, high throughput, size-sensitive sorting and trapping of particles much smaller than the bubble itself. We propose a simple geometric mechanism, based on flow speeds and channel …
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The Microbubble Assisted Bioremediation of Chlorinated Ethenes
This work focused on using a microbubble dispersion to deliver hydrogen and carbon dioxide to anaerobic consortia to stimulate their ability to reductively dehalogenate tetrachloroethylene all the way to ethene and ethane. A continuous flow system, consisting of six anaerobic soil column …
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OpenFOAM Implementation of Microbubble Models for Ocean Applications
An investigation was carried out on the current state of the art in bubble modelling for computational fluid dynamics, and comparisons made between the different methods for both polydisperse and monodisperse multiphase flows. A multigroup method for polydisperse bubbly flows with the bubbles …
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Generation of microbubble foam using a packed column
A technique for generating microbubble foams from a dilute surfactant solution using a column packed with millimeter sized glass beads is examined. The investigation requires the fabrication of a test unit capable of producing microbubble foam at 40 L/min and design and fabrication of a packed bed …
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Parametric study and simulation of microbubble column flotation
… for advanced physical fine coal cleaning using microbubble column flotation. The dependent variables in these experiments were mass yield and product quality (ash, sulfur and btu), while the independent variables were feed solids content, collector dosage, frother dosage, feed rate, aeration …
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A Study of Rhamnolipid Microbubble Dispersion for Bioremediation Applications
This thesis presents a study on the production of microbubble dispersions from rhamnolipid biosurfactant and the mechanism and factors that impact upon the effectiveness of the dispersion for improving bioremediation efficiency, with a specific focus on the use of microbubble dispersion as a …
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Processing of high-sulfur coals using microbubble column flotation
… to the S02 problem. In this investigation, the microbubble column flotation process (MCF), developed at VPI&SU, was tested as a means of reducing the pyritic sulfur content of several high-sulfur coals targeted by the u.S. Department of Energy. A wide variety of pyrite rejection schemes were …
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A preliminary investigation of microbubble flotation of fine coal
… conducted on several Appalachian coals using microbubbles in a cylindro-conical flotation column. Results indicate that this technique shows improvements over the conventional technique using larger bubbles, when the coal is ultrafine. The improvement in recovery rate with the microbubbles is …
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Intensification of Gas Absorption in a Downward Flow Microbubble Bioreactor
… feedstock at ambient pressure into a downward microbubble flow. The performance of this device exceeds known technology in terms of volumetric gas transfer energy efficiency defined as reactor divided by reactor power density (achieving values near 0.34 s<sup>-1</sup> m<sup>3</sup> …
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Development & testing of ultrasound enhanced prodrug microbubble drug delivery system
Microbubble drug delivery systems vary widely in their design and. This work focused on the application of a novel microbubble system with ultrasound-mediated delivery enhancement via consumer equipment. The work involved the creation of a novel microbubble formulation using a prodrug of Bexarotene …
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Characterization and scale-up of microbubble generation in column flotation
… (or static) mixers can successfully produce microbubbles for column flotation. Unfortunately, few guidelines exist for selecting the proper size and type of motionless mixer for generating microbubbles. In the present work, the mean bubble size produced by various types of in-line motionless …
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Microbubble streaming flows for non-invasive particle manipulation and liquid mixing
… we study an emerging actuating mechanism -- microbubble steady streaming flows -- by emphasizing both fundamental understanding and the design and applications of bubble-based microfluidic devices. Under periodic acoustical driving, microbubbles with radius 20 -- 100µm absorbed or attached to …
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Microbubble fermentation of recombinant Pichia pastoris for human serum albumin production
… agitation rate and use of oxygen-enriched air. Microbubble fermentation however can supply adequate oxygen to the microorganisms at relatively low agitation rates because of improved mass transfer of the microbubbles used for the sparging. Conventionally sparged fermentations were conducted for …
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Increased oxygen transfer in a yeast fermentation using a microbubble dispersion
The use of a microbubble dispersion (MBD) for oxygen transport in a yeast fermentation was studied. No surfactants were added to the fermentations; the microbubbles were formed using only the surfactants naturally produced by the yeast. The growth rate of a Saccharomyces cerevisiae culture was …
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Microbubble localization using multivariate gaussian fitting for super-resolution ultrasound localization microscopy
… ultrasound localization microscopy, current microbubble localization methods need spatially isolated microbubble signal and overlapping microbubble signals are rejected or treated as single isolated microbubbles. Overlapping microbubbles would convey equally important information as isolated …
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Investigation of Microbubble-enhanced Mild Hyperthermia with Focused Ultrasound for Drug Delivery Enhancement
… size area. Prior work has shown that adding microbubbles during HIFU can enhance the heating. It was suggested that there exists an optimal microbubble concentration that varies with respect to acoustic pressure amplitude that results in enhanced heating and larger lesion formation for …
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