Local Electric Field Strength in a Hollow Cathode Determined by Stark Splitting of the 2S Level of Hydrogen Isotopes by Optogalvanic Spectroscopy

2008 ◽  
Author(s):  
C. Pérez ◽  
M. I. de la Rosa ◽  
K. Grützmacher ◽  
A. B. Gonzalo ◽  
L. M. Fuentes ◽  
...  
2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yan Mi ◽  
Quan Liu ◽  
Pan Li ◽  
Jin Xu

Carbon nanotubes (CNTs) with large aspect ratios and excellent electrical properties can enhance the killing effect of nanosecond pulsed electric fields (nsPEFs) on tumor cells, which can improve the electrical safety of nsPEF during tumor treatment. To study the mechanism of the CNT-enhanced killing effect of a nsPEF on tumor cells, a spherical, single-cell, five-layer dielectric model containing randomly distributed CNTs was established using COMSOL and MATLAB, and then, the effects of the addition of CNTs on the electric field and the electroporation effect on the inner and outer membranes were analyzed. The results showed that CNTs can enhance the local electric field strength due to a lightning rod effect, and the closer the CNT tip was to the cell, the greater the electric field strength was around the cell. This increase in the local electric field strength near the cells enhanced the electroporation effects, including pore density, pore area, and pore flux. The simulation results presented in this paper provide theoretical guidance for subsequent development of nsPEF combined with CNTs for use in both cell and tissue experiments.


Inventions ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 2 ◽  
Author(s):  
Sanam Pudasaini ◽  
A. T. K. Perera ◽  
Syed. S. U. Ahmed ◽  
Yong Bing Chong ◽  
Sum Huan Ng ◽  
...  

This paper presents an electroporation device with high bacterial inactivation performance (~4.75 log removal). Inside the device, insulating silica microbeads are densely packed between two mesh electrodes that enable enhancement of the local electric field strength, allowing improved electroporation of bacterial cells. The inactivation performance of the device is evaluated using two model bacteria, including one Gram-positive bacterium (Enterococcus faecalis) and one Gram-negative bacterium (Escherichia coli) under various applied voltages. More than 4.5 log removal of bacteria is obtained for the applied electric field strength of 2 kV/cm at a flowrate of 4 mL/min. The effect of microbeads on the inactivation performance is assessed by comparing the performance of the microbead device with that of the device having no microbeads under same operating conditions. The comparison results show that only 0.57 log removal is achieved for the device having no microbeads—eightfold lower than for the device with microbeads.


2015 ◽  
Vol 37 ◽  
pp. 13-19 ◽  
Author(s):  
A Young Choi ◽  
Hyeon Jun Sim ◽  
Min Kyoon Shin ◽  
Seon Jeong Kim ◽  
Youn Tae Kim

We confirm piezoelectric performance of bottom electrospun PVDF-TrFE mat is higher than that of top mat and report the mechanism of additional poling process of electrospun nanofibers by local electric field which is originating from residual charges in far-field electrospinning process. Piezoelectric output measurement of poly (vinylidene fluoride-co-trifluoroethylene) electrospun nanofibers was performed by push test and output signals of bottom and top were compared. The local electric field strength calculated by simulation was higher than reported electric field strength of near-field electrospinning (10 MV/m). It can be concluded that the piezoelectric outputs of electrospun nanofibers tend to be improved by residual charge density and electrospinning condition.


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