scholarly journals Directional transport and random motion of particles in ALF ultrasonic cavitation structure

2021 ◽  
Vol 72 ◽  
pp. 105439
Author(s):  
Yuhang Ma ◽  
Zhijie Zeng ◽  
Weilin Xu ◽  
Lixin Bai
Keyword(s):  
Random Motion ◽  
Ultrasonic Cavitation ◽  
Directional Transport

Micromachined Linear Brownian Motor: A Nanosystem Exploting Brownian Motion of Nanobeads for Uni-directional Transport

2008 ◽  
Vol 1096 ◽  
Author(s):  
Ersin Altintas ◽  
Edin Sarajlic ◽  
Karl F. Bohringer ◽  
Hiroyuki Fujita
Keyword(s):  
Brownian Motion ◽  
Three Dimensional ◽  
Thermal Fluctuations ◽  
Random Motion ◽  
Microfluidic Channels ◽  
Switching Sequence ◽  
Brownian Motor ◽  
Speed Performance ◽  
Random Fluctuations ◽  
Directional Transport

AbstractNanosystems operating in liquid media may suffer from random thermal fluctuations. Some natural nanosystems, e.g. biomolecular motors, which survive in an environment where the energy required for bio-processes is comparable to thermal energy, exploit these random fluctuations to generate a controllable unidirectional movement. Inspired by the nature, a transportation system of nanobeads achieved by exploiting Brownian motion were proposed and realized. This decreases energy consumption and saves the energy compared to ordinal pure electric or magnetic drive. In this paper we present a linear Brownian motor with a 3-phase electrostatic rectification aimed for unidirectional transport of nanobeads in microfluidic channels. The transport of the beads is performed in 1 μm deep, 2 μm wide PDMS microchannels, which constrain three-dimensional random motion of nanobeads into 1D fluctuation, so-called tamed Brownian motion. We have experimentally traced the rectified motion of nanobeads and observed the shift in the beam distribution as a function of applied voltage. The detailed computational analysis on the importance of switching sequence on the speed performance of motor is performed and compared with the experimental results showing a good agreement.

Platelet Aggregation Induced in Vitro by Therapeutic Ultrasound

1977 ◽  
Vol 38 (03) ◽  
pp. 0640-0651 ◽  
Author(s):  
B. V Chater ◽  
A. R Williams
Keyword(s):  
Platelet Aggregation ◽  
Direct Action ◽  
Adenosine Diphosphate ◽  
Ultrasonic Cavitation ◽  
Related Phenomenon ◽  
Release Reaction ◽  
Physical Conditions ◽  
Platelet Aggregates ◽  
Active Substances

SummaryPlatelets were found to aggregate spontaneously when exposed to ultrasound generated by a commercial therapeutic device. At a given frequency, aggregation was found to be a dose-related phenomenon, increasing intensities of ultrasound inducing more extensive and more rapid aggregation. At any single intensity, the extent aggregation was increased as the frequency of the applied ultrasound was decreased (from 3.0 to 0.75 MHz).Ultrasound-induced platelet aggregation was found to be related to overall platelet sensitivity to adenosine diphosphate. More sensitive platelets were found to aggregate spontaneously at lower intensities of sound, and also the maximum extent of aggregation was found to be greater. Examination of ultrasound-induced platelet aggregates by electron microscopy demonstrated that the platelets had undergone the release reaction.The observation that haemoglobin was released from erythrocytes in whole blood irradiated under identical physical conditions suggests that the platelets are being distrupted by ultrasonic cavitation (violent gas/bubble oscillation).It is postulated that overall platelet aggregation is the result of two distinct effects. Firstly, the direct action of ultrasonic cavitation disrupts a small proportion of the platelet population, resulting in the liberation of active substances. These substances produce aggregation, both directly and indirectly by inducing the physiological release reaction in adjacent undamaged platelets.

Treatment of ulcer-necrotic manifestations of diabetic foot using ultrasonic cavitation

2014 ◽  
Author(s):  
Maksym Prystupiuk ◽  
Iuliia Onofriichuk ◽  
Liudmyla Naumova ◽  
Lev Prystupiuk ◽  
Marianna Naumova ◽  
...  
Keyword(s):  
Diabetic Foot ◽  
Ultrasonic Cavitation

Visualization of ultrasonic cavitation in visible and IR spectra

2010 ◽  
Author(s):  
A. Osterman ◽  
O. Coutier-Delgosha ◽  
M. Hocevar ◽  
B. Sirok
Keyword(s):  
Ir Spectra ◽  
Ultrasonic Cavitation

scholarly journals Efficient Sequestration of Hexavalent Chromium by Graphene-Based Nanoscale Zero-Valent Iron Composite Coupled with Ultrasonic Pretreatment

2021 ◽  
Vol 18 (11) ◽  
pp. 5921
Author(s):  
Haiyan Song ◽  
Wei Liu ◽  
Fansheng Meng ◽  
Qi Yang ◽  
Niandong Guo
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Inhibitory Effect ◽  
Ultrasonic Cavitation ◽  
Zero Valent Iron ◽  
Ultrasonic Pretreatment ◽  
Nanoscale Zero Valent Iron ◽  
Passivation Layers ◽  
Initial Ph ◽  
Two Phases

Nanoscale zero-valent iron (nZVI) has attracted considerable attention for its potential to sequestrate and immobilize heavy metals such as Cr(VI) from an aqueous solution. However, nZVI can be easily oxidized and agglomerate, which strongly affects the removal efficiency. In this study, graphene-based nZVI (nZVI/rGO) composites coupled with ultrasonic (US) pretreatment were studied to solve the above problems and conduct the experiments of Cr(VI) removal from an aqueous solution. SEM-EDS, BET, XRD, and XPS were performed to analyze the morphology and structures of the composites. The findings showed that the removal efficiency of Cr(VI) in 30 min was increased from 45.84% on nZVI to 78.01% on nZVI/rGO and the removal process performed coupled with ultrasonic pretreatment could greatly shorten the reaction time to 15 min. Influencing factors such as the initial pH, temperature, initial Cr(VI) concentration, and co-existing anions were studied. The results showed that the initial pH was a principal factor. The presence of HPO42−, NO3−, and Cl− had a strong inhibitory effect on this process, while the presence of SO42− promoted the reactivity of nZVI/rGO. Combined with the above results, the process of Cr(VI) removal in US-nZVI/rGO system consisted of two phases: (1) The initial stage is dominated by solution reaction. Cr(VI) was reduced in the solution by Fe2+ caused by ultrasonic cavitation. (2) In the following processes, adsorption, reduction, and coprecipitation coexisted. The addition of rGO enhanced electron transportability weakened the influence of passivation layers and improved the dispersion of nZVI particles. Ultrasonic cavitation caused pores and corrosion at the passivation layers and fresh Fe0 core was exposed, which improved the reactivity of the composites.

Ultrasonic cavitation driven fabrication of organic solvent free lignin/prochloraz nano capsules to promote resistance to photolysis and rain wash, and provide extended release performance

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jingtian Chen ◽  
Miao Wang ◽  
Yong Qian ◽  
Shanyuan Tan ◽  
Huan Wang ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Uv Irradiation ◽  
Encapsulation Efficiency ◽  
Extended Release ◽  
Ultrasonic Cavitation ◽  
Solvent Free ◽  
Loading Capacity ◽  
One Pot ◽  
Continuous Release ◽  
Mango Leaves

Abstract Lignin is a natural macromolecular sun blocker and provides an ideal protection material for pesticides that have poor photostability. In this study, alkali lignin/prochloraz capsules (AL-P) were prepared via one-pot ultrasonic cavitation. The results demonstrated that the produced AL-P were uniform spheres with sizes of 170–375 nm. The prochloraz encapsulation efficiency (EE) and loading capacity (LC) reached as high as 91.8 and 98.5%, respectively. Adding a small of surfactant reduced the size of the capsules, but both EE and LC were decreased. AL-P exhibited excellent extended release performance. The cumulative release of AL-P in the first 45 h was 76.1% and continuous release was maintained after 96 h. The resulting AL-P have improved photostability under UV irradiation radiation. Finally, AL-P capsules were sprayed on the mango leaves and bananas to act as preservatives, AL-P capsules had stronger rain wash resistance and were better preserved demonstrating their industrial applicability. Together, organic solvent free AL-P capsules demonstrate a method to improve the efficiency of photosensitive pesticides.

Initial-Position-Driven Opposite Directional Transport of Water Droplet on Wedge-Shaped Groove

Nanoscale ◽  
2021 ◽  
Author(s):  
Shaoqian Hao ◽  
Xie Zhang ◽  
Zheng Li ◽  
Jianlong Kou ◽  
Fengmin Wu
Keyword(s):  
Water Droplet ◽  
Initial Position ◽  
Water Droplets ◽  
Transport Direction ◽  
Directional Transport ◽  
Prevailing View ◽  
Functionalized Surface

Transport direction of water droplets on a functionalized surface is of great significance due to its wide applications in microfluidics technology. The prevailing view is that a water droplet on...

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