High-resolution separation and accurate size determination in pulsed-field gel electrophoresis of DNA. 2. Effect of pulse time and electric field strength and implications for models of the separation process

Biochemistry ◽  
1988 ◽  
Vol 27 (26) ◽  
pp. 9210-9216 ◽  
Author(s):  
Mathew K. Mathew ◽  
Cassandra L. Smith ◽  
Charles R. Cantor
Keyword(s):  
High Resolution ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Separation Process ◽  
Size Determination ◽  
Pulse Time ◽  
Dna 2

scholarly journals Experimental Study on the Performance of a Novel Compact Electrostatic Coalescer with Helical Electrodes

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1733
Author(s):  
Yi Shi ◽  
Jiaqing Chen ◽  
Zehao Pan
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Water Content ◽  
Water Droplet ◽  
Separation Process ◽  
Water Droplets ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water

As most of the light and easy oil fields have been produced or are nearing their end-life, the emulsion stability is enhanced and water cut is increasing in produced fluid which have brought challenges to oil–water separation in onshore and offshore production trains. The conventional solution to these challenges includes a combination of higher chemical dosages, larger vessels and more separation stages, which often demands increased energy consumption, higher operating costs and larger space for the production facility. It is not always feasible to address the issues by conventional means, especially for the separation process on offshore platforms. Electrostatic coalescence is an effective method to achieve demulsification and accelerate the oil–water separation process. In this paper, a novel compact electrostatic coalescer with helical electrodes was developed and its performance on treatment of water-in-oil emulsions was investigated by experiments. Focused beam reflectance measurement (FBRM) was used to make real-time online measurements of water droplet sizes in the emulsion. The average water droplet diameters and number of droplets within a certain size range are set as indicators for evaluating the effect of coalescence. We investigated the effect of electric field strength, frequency, water content and fluid velocity on the performance of coalescence. The experimental results showed that increasing the electric field strength could obviously contribute to the growth of small water droplets and coalescence. The extreme value of electric field strength achieved in the high-frequency electric field was much higher than that in the power-frequency (50 Hz) electric field, which can better promote the growth of water droplets. The initial average diameters of water droplets increase with higher water content. The rate of increment in the electric field was also increased. Its performance was compared with that of the plate electrodes to further verify the advantages of enhancing electrostatic coalescence and demulsification with helical electrodes. The research results can provide guidance for the optimization and performance improvement of a compact electrocoalescer.

scholarly journals Об ускорении релятивистской частицы импульсом излучения

2019 ◽  
Vol 126 (2) ◽  
pp. 211
Author(s):  
Н.Н. Розанов
Keyword(s):  
Laser Radiation ◽  
Laser Pulse ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Laser Pulses ◽  
Pulse Time ◽  
Dominant Component ◽  
Wide Range ◽  
Mechanical Momentum

AbstractConcerning direct acceleration of charges by pulses of electromagnetic (laser) radiation with arbitrary shapes, we have found a relationship between the components of the mechanical momentum of a relativistic (but not ultrarelativistic) particle. In a wide range of conditions, the energy transferred by the radiation to a particle to be accelerated is determined by the electric area of the laser pulse, i.e., by the integral of the electric field strength over the pulse time. This indicates that it is promising to develop schemes for generation of quasi-unipolar radiation laser pulses, in which the strength of the dominant component of the electric field does not change its sign during the main pulse duration.

Sign in / Sign up

Export Citation Format

Share Document