Cyclic classification of micropowders in a variable electric field

1979 ◽  
Vol 18 (3) ◽  
pp. 200-203 ◽  
Author(s):  
N. K. Naremskii
2000 ◽  
Vol 104 (18) ◽  
pp. 4167-4173 ◽  
Author(s):  
Jason C. Kirkwood ◽  
Darin J. Ulness ◽  
Albrecht

2019 ◽  
Vol 213 ◽  
pp. 02053
Author(s):  
Frantisek Lizal ◽  
Milan Maly ◽  
Jakub Elcner ◽  
Arpad Farkas ◽  
Ondrej Pech ◽  
...  

Particles exposed to an electric field experience forces that influence their movement. This effect can be used for filtration of air, or for size classification of aerosols. The motion of charged particles in a non-uniform electric field is called electrophoresis. Two processes are involved in this phenomenon: 1) charging of particles and 2) electrical mobility separation. If fibres are exposed to electrophoresis, they are separated on the basis of two parameters: diameter and length. Regrettably, as naturally occurring fibres are polydisperse both in diameter and length, the electrophoresis is not very efficient in length classification. In contrast, dielectrophoresis is the motion of electrically neutral particles in a non-uniform electric field due to the induced charge separation within the particles. As deposition velocity of fibres induced by dielectrophoretic force strongly depends on length and only weakly on diameter, it can be used for efficient length classification. Principles of length classification of conducting and non-conducting fibres are presented together with design of a fibre classifier. Lastly, images of motion of fibres recorded by high-speed camera are depicted.


2020 ◽  
Vol 10 (12) ◽  
pp. 4244
Author(s):  
Paulius Butkus ◽  
Arūnas Murauskas ◽  
Sonata Tolvaišienė ◽  
Vitalij Novickij

Electroporation is a pulsed electric field triggered phenomenon of cell permeabilization, which is extensively used in biomedical and biotechnological context. There is a growing scientific demand for high-voltage and/or high-frequency pulse generators for electropermeabilization of cells (electroporators). In the scope of this article we have reviewed the basic topologies of nanosecond pulsed electric field (nsPEF) generators for electroporation and the parametric capabilities of various in-house built devices, which were introduced in the last two decades. Classification of more than 60 various nsPEF generators was performed and pulse forming characteristics (pulse shape, voltage, duration and repetition frequency) were listed and compared. Lastly, the trends in the development of the electroporation technology were discussed.


2006 ◽  
Vol 63 (1) ◽  
pp. 218-233 ◽  
Author(s):  
Robbie E. Hood ◽  
Daniel J. Cecil ◽  
Frank J. LaFontaine ◽  
Richard J. Blakeslee ◽  
Douglas M. Mach ◽  
...  

Abstract During the 1998 and 2001 hurricane seasons of the western Atlantic Ocean and Gulf of Mexico, the Advanced Microwave Precipitation Radiometer (AMPR), the ER-2 Doppler (EDOP) radar, and the Lightning Instrument Package (LIP) were flown aboard the NASA ER-2 high-altitude aircraft as part of the Third Convection and Moisture Experiment (CAMEX-3) and the Fourth Convection and Moisture Experiment (CAMEX-4). Several hurricanes, tropical storms, and other precipitation systems were sampled during these experiments. An oceanic rainfall screening technique has been developed using AMPR passive microwave observations of these systems collected at frequencies of 10.7, 19.35, 37.1, and 85.5 GHz. This technique combines the information content of the four AMPR frequencies regarding the gross vertical structure of hydrometeors into an intuitive and easily executable precipitation mapping format. The results have been verified using vertical profiles of EDOP reflectivity and lower-altitude horizontal reflectivity scans collected by the NOAA WP-3D Orion radar. Matching the rainfall classification results with coincident electric field information collected by the LIP readily identifies convective rain regions within the precipitation fields. This technique shows promise as a real-time research and analysis tool for monitoring vertical updraft strength and convective intensity from airborne platforms such as remotely operated or uninhabited aerial vehicles. The technique is analyzed and discussed for a wide variety of precipitation types using the 26 August 1998 observations of Hurricane Bonnie near landfall.


1975 ◽  
Vol 14 (8) ◽  
pp. 614-616 ◽  
Author(s):  
N. K. Naremskii ◽  
V. Ya. Gomelich ◽  
A. N. Shabaev

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