Regularities of non-stationary diffusion growth of overcritical gas bubbles and kinetics of bubble distribution in presence of capillary and viscous forces

2021 ◽  
Vol 154 (14) ◽  
pp. 144101
Author(s):  
Anatoly E. Kuchma ◽  
Alexander K. Shchekin
Keyword(s):  
Gas Bubbles ◽  
Diffusion Growth ◽  
Viscous Forces ◽  
Bubble Distribution ◽  
Stationary Diffusion ◽  
Kinetics Of

Kinematics and Kinetics of Flagellar Locomotion in Chlamydomonas Reinhardtii

2011 ◽  
Author(s):  
P. V. Bayly ◽  
B. L. Lewis ◽  
E. C. Ranz ◽  
R. J. Okamoto ◽  
R. B. Pless ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Video Data ◽  
Wild Type ◽  
Viscous Forces ◽  
Sorting Algorithms ◽  
Theoretical Predictions ◽  
Dynein Arms ◽  
Kinetics Of ◽  
Kinematics And Kinetics ◽  
Surrounding Fluid

The forces exerted on the flagellum of the swimming alga Chlamydomonas reinhardtii by surrounding fluid are estimated from video data. “Wild-type” cells, as well as cells lacking inner dynein arms (ida3) and cells lacking outer dynein arms (oda2) were imaged (350 fps; 125 nm). Digital image registration and sorting algorithms provide high-resolution descriptions of the kinematics of the cell body and flagellum. The swimming cell is then modeled as an ellipsoid in Stokes flow, propelled by viscous forces that depend linearly on the velocity of the flagellum. The coefficients (CN and CT) that related normal and tangent forces on the flagellum to corresponding velocity components are estimated from equilibrium requirements. Their values are consistent among all three genotypes and similar to theoretical predictions.

Viscous forces on acoustically levitated gas bubbles

2005 ◽  
Vol 63 (5-7) ◽  
pp. e1517-e1527 ◽  
Author(s):  
Darren L. Hitt ◽  
Andrea Prosperetti
Keyword(s):  
Gas Bubbles ◽  
Viscous Forces

scholarly journals Ultrasonic Transmission Tomography Sensor Design for Bubble Identification in Gas-Liquid Bubble Column Reactors

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4256 ◽  
Author(s):  
Nan Li ◽  
Mingchen Cao ◽  
Kun Xu ◽  
Jiabin Jia ◽  
Hangben Du
Keyword(s):  
Bubble Column ◽  
Excitation Frequency ◽  
Gas Bubbles ◽  
Gas Bubble ◽  
Transmission Tomography ◽  
Bubble Distribution ◽  
Bubble Column Reactors ◽  
Imaging Results ◽  
Liquid Bubble ◽  
And Diffusion

Scientists require methods to monitor the distribution of gas bubbles in gas-liquid bubble column reactors. One non-destructive method that can potential satisfy this requirement in industrial situations is ultrasonic transmission tomography (UTT). In this paper, an ultrasonic transmission tomography sensor is designed for measuring bubble distribution in a reactor. Factors that influence the transducer design include transmission energy loss, the resonance characteristics and vibration modes of the transducer, and diffusion angles of the transducers, which are discussed. For practical application, it was found that an excitation frequency of 300 kHz could identify the location and size of gas bubbles. The vibration mode and diffusion also directly affect the quality of the imaging. The geometric parameters of the transducer (a cylinder transducer with a 10 mm diameter and 6.7 mm thickness) are designed to achieve the performance requirements. A UTT system, based on these parameters, was built in order to verify the effectiveness of the designed ultrasonic transducer array. A Sector-diffusion-matrix based Linear Back Projection (SLBP) was used to reconstruct the gas/liquid two-phase flow from the obtained measurements. Two other image processing methods, based on SLBP algorithm named SLBP-HR (SLBP-Hybrid Reconstruction) and SLBP-ATF (SLBP-Adaptive Threshold Filtering), were introduced, and the imaging results are presented. The imaging results indicate that a gas bubble with a 3 mm radius can be identified from reconstructed images, and that three different flow patterns, namely, single gas bubble, double gas bubble with different diameters, and eccentric flow, can be identified from reconstructed images. This demonstrates that the designed UTT sensor can effectively measure bubble distribution in gas-liquid bubble column reactors.

Kinetics of diffusion growth of silicides in silicon–thin‐metal‐film systems

1992 ◽  
Vol 72 (4) ◽  
pp. 1356-1361 ◽  
Author(s):  
A. I. Barg ◽  
B. S. Bokstein ◽  
L. M. Klinger
Keyword(s):  
Metal Film ◽  
Thin Metal Film ◽  
Thin Metal ◽  
Diffusion Growth ◽  
Kinetics Of
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