Investigation of Hydrodynamic Surface Waves with a Cylindrical Microwave Resonator. IV. Application of a Strong Electrostatic Field

1971 ◽  
Vol 49 (4) ◽  
pp. 458-466 ◽  
Author(s):  
F. L. Curzon ◽  
G. N. Ionides
Keyword(s):  
Electric Field ◽  
Surface Waves ◽  
Electrostatic Field ◽  
Oscillation Frequency ◽  
Wave Amplitude ◽  
Equations Of Motion ◽  
Experimental Results ◽  
Microwave Resonator ◽  
Uniform Field ◽  
Static Electric Field

The reduction of the oscillation frequency of surface waves caused by a static electric field normal to the surface has been investigated with a microwave resonator. The stationary deformation of the surface caused by the spatially non-uniform field has been used to verify that the detectable wave amplitude is of the order of 5 × 10−3 cm, which is much smaller than other scale lengths (> 1 cm) of the system. The results can therefore justifiably be compared with the predictions of the linearized equations of motion. The experimental results agree well with the theory, which takes into account the spatial non-uniformity of the electrostatic field.

Nonlinear Effects in Resonantly Driven Surface Waves on Fluids

1972 ◽  
Vol 50 (19) ◽  
pp. 2235-2243
Author(s):  
F. L. Curzon ◽  
G. N. Ionides
Keyword(s):  
Surface Waves ◽  
Electric Fields ◽  
Driving Force ◽  
Wave Amplitude ◽  
Nonlinear Effects ◽  
Microwave Resonator ◽  
Electrode Geometry ◽  
Fluid Surface ◽  
Electric Stress ◽  
Time Periodic

The results presented in this paper show that fluid surface waves, resonantly driven by spatially nonuniform, time periodic electric fields, exhibit nonlinear effects when the wave amplitude ξ exceeds a significant fraction of the distance D between the driver electrode and the fluid surface. The phase difference between the surface wave and the driving force, as well as the dependence of wave amplitude on the electric stress are computed and compared with experimental results. For ξ/D exceeding ~0.7 (dependent on electrode geometry) the surface waves excited are unstable (also confirmed experimentally). The experiments are performed on surface waves on mercury contained in a cylindrical microwave resonator. Shifts in the microwave resonant frequency (caused by the surface waves) monitor the displacement of the fluid surface.

scholarly journals Effect of high-voltage electrostatic field on cryopreservation of human epidermal melanocytes

2021 ◽  
Vol 233 ◽  
pp. 02039
Author(s):  
Xu Cai ◽  
Pengcheng Li ◽  
Benke Chen ◽  
Qian Li ◽  
Jintian Tang ◽  
...  
Keyword(s):  
Electric Field ◽  
High Voltage ◽  
Electrostatic Field ◽  
Physiological Activity ◽  
Proliferation Rate ◽  
Cell Deformation ◽  
Control Group ◽  
Freezing Damage ◽  
Static Electric Field ◽  
Supercooling Degree

The objective of this research was to evaluate the influence of high-voltage electrostatic field (HVEF) on the freezing of human epidermal melanocytes (HEM) with respect to the degree of cell deformation, survival and proliferation rate after cell resuscitation. As a result, the degree of supercooling is increased by enhancing the strength of the static electric field in the range of 15 kV/m, and the maximum supercooling degree is 7.83±0.05 °C at 15 kV/m. By contrast, the morphology of the electric field assisted freezing cell after resuscitation was significantly improved, and the best electric field strength for cryopreservation is 15 kV/m. The survival rate of human epidermal melanocytes recovered was 88.03%, which was higher than that of the control group. The proliferation rate at 24, 48 and 72 hours are 17%, 28% and 25%, respectively, which are higher than that of the control cells. These findings demonstrate that the freezing HVEF can protect the cell physiological activity, and reduce the freezing damage. Therefore, the optimal HVEF cryopreservation technology be of great significance for the research of tissue engineering in repairing wounds, infections, and promote the development of food, medicine and other fields.

Mechanism of Slug Formation in Horizontal Two-Phase Flow

1970 ◽  
Vol 92 (4) ◽  
pp. 857-864 ◽  
Author(s):  
E. S. Kordyban ◽  
T. Ranov
Keyword(s):  
Theoretical Prediction ◽  
Surface Waves ◽  
Flow Pattern ◽  
Slug Flow ◽  
Wave Amplitude ◽  
Experimental Results ◽  
Phase Flow ◽  
Helmholtz Instability ◽  
Two Phase ◽  
Good Agreement

It is proposed in this work that the transition to slug flow occurs due to Kelvin-Helmholtz instability, which, in this case, is enhanced by the proximity of the upper wall and becomes wave-amplitude dependent. Since the surface waves possess a limiting amplitude, the transition can be predicted by examining whether the highest possible waves are unstable. The theoretical prediction is in good agreement with the authors’ experimental results. It also agrees reasonably well with Baker’s and Schicht’s flow pattern charts for strictly horizontal channels, but it exhibits large differences when the channels deviate somewhat from the horizontal.

Resolution in photoelectron microscopy

1991 ◽  
Vol 49 ◽  
pp. 458-459
Author(s):  
G. F. Rempfer
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Ultraviolet Light ◽  
Uniform Field ◽  
Virtual Image ◽  
Lens System ◽  
Photoemission Electron Microscopy ◽  
Planar Electrode ◽  
Electron Lens ◽  
Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

Transient Response of Electrostatic Field due to Collision ESD between Spherical Electrodes by using Bare-chip Optical Electric Field Sensor

2020 ◽  
Vol 140 (12) ◽  
pp. 599-600
Author(s):  
Kento Kato ◽  
Ken Kawamata ◽  
Shinobu Ishigami ◽  
Ryuji Osawa ◽  
Takeshi Ishida ◽  
...  
Keyword(s):  
Electric Field ◽  
Transient Response ◽  
Electrostatic Field ◽  
Electric Field Sensor ◽  
Field Sensor

Behaviors of NaCl Ions Intruding into Methane Hydrate under a Static Electric Field

2021 ◽  
Vol 125 (33) ◽  
pp. 18483-18493
Author(s):  
Kehan Li ◽  
Bingbing Chen ◽  
Mingjun Yang ◽  
Yongchen Song ◽  
Lanlan Jiang
Keyword(s):  
Electric Field ◽  
Methane Hydrate ◽  
Static Electric Field
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