scholarly journals Влияние усиленной электрическим полем термической электронной эмиссии на температуру катода с тонкой диэлектрической пленкой в дуговом газовом разряде

2020 ◽  
Vol 90 (5) ◽  
pp. 862
Author(s):  
Г.Г. Бондаренко ◽  
М.С. Дубинина ◽  
В.И. Кристя
Keyword(s):  
Electric Field ◽  
Cathode Surface ◽  
Thermal Emission ◽  
Arc Discharge ◽  
Thermal Electron ◽  
Metal Insulator ◽  
Discharge Current Density ◽  
Metal Cathode ◽  
Cathode Substrate ◽  
Cathode Temperature

A model of thermal electron emission enhanced by the electric field (thermo-field emission) from the metal cathode substrate into a thin insulating film formed on its surface is developed. A system of equations for the cathode surface temperature in the arc discharge and the electric field strength in the film, providing the required discharge current density, is formulated. It is shown that existence of the dielectric film can result in a considerable reduction of the cathode temperature in the discharge due to lower potential barrier height at the metal-insulator boundary than at the metal-discharge boundary in case of the metal cathode without the film. It is found that due to an enhancement of thermal emission of electrons into the film by the electric field generated in it, an additional decrease of the cathode temperature by about 100 K takes place.

Thermal Conditions Favoring Buckytube Growth on the Anode

1994 ◽  
Vol 368 ◽  
Author(s):  
Nikola Koprinarov ◽  
Miko Marinov ◽  
George Pchelarov ◽  
Mariana Konstantinova ◽  
Radoslav Stefanov
Keyword(s):  
Temperature Difference ◽  
Thermal Emission ◽  
Arc Discharge ◽  
Thermal Conditions ◽  
High Ratio ◽  
Vapor Source ◽  
Regime Changes ◽  
Heating And Cooling ◽  
Cathode Temperature ◽  
Favorable Conditions

ABSTRACTThe most widespread methoid for buckytube synthesis is by arc discharge in an inert gas ambient. At arc discharge the major kind of charge carriers are the electrons generated from the cathode by thermal emission. For this reason up until now the deposit was always obtained on the cathode. By supplementary electrode heating and cooling we studied the effects of the anode-cathode temperature difference and found that it plays a major role in defining the quality and quantity of the deposit obtained. Given appropriate heat-up or cool-down of the electrodes, a state can be reached such that the temperature at the cathode is higher than the temperature at the anode. A deposit was obtained on the anode, observed by a TEM. In our view employing this method yields the most favorable conditions for buckytube growth. Our results show that except buckytubes with a high ratio of their length with respect to their width, a multitude of small size polyhedral carbon systems closed in by spatial carbon nets and thin flat interfering carbon plates were also obtained. When using electrodes of different cross-section, with the deposition of an ever thicker deposit on the anode, its temperature regime changes. The lower initial temperature at the anode begins to grow steadily with time tending towards the temperature at the cathode. Thus, buckytube growth proceeds at the lowest possible rate, at a small temperature difference between the vapor source and growing structure. In our view employing this method yields the most favorable conditions for buckytube growth.

scholarly journals Selective Arcing Electrostatically Eradicates Rice Weevils in Rice Grains

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 522
Author(s):  
Koji Kakutani ◽  
Yoshihiro Takikawa ◽  
Yoshinori Matsuda
Keyword(s):  
Electric Field ◽  
Arc Discharge ◽  
Rice Grains ◽  
Voltage Generator ◽  
Metal Plates

We developed an arc discharge exposer (ADE) that kills rice weevils nesting in dried rice. The ADE features multiple identical metal plates, half of these are linked to a voltage generator and the others are grounded. The plates were arrayed in parallel and an electric field formed between them. Any insect entering the field was arced from the negatively charged plate and killed. The ADE was placed on a vessel containing pest-infested rice grains; the insects were lured out of the grains by mechanically vibrating the vessel. When rice grains move, insects tend to climb upward, thus, the weevils were effectively removed. Our electrostatic apparatus is easy to construct and could be used to control pests in stored rice.

scholarly journals Design of a Liquid-Crystal-Tunable Terahertz Demultiplexer Based on a Metal-Insulator-Metal Waveguide

2019 ◽  
Vol 9 (4) ◽  
pp. 644
Author(s):  
Xue-Shi Li ◽  
Naixing Feng ◽  
Yuan-Mei Xu ◽  
Liang-Lun Cheng ◽  
Qing Liu
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Metal Insulator ◽  
Resonance Modes ◽  
External Bias ◽  
Bias Electric Field ◽  
Metal Waveguide ◽  
Metal Insulator Metal ◽  
Fabry Perot ◽  
Mim Waveguide

A tunable demultiplexer with three output channels infiltrated by liquid crystal (LC) is presented, which is based on a metal-insulator-metal (MIM) waveguide. The operating frequencies of the three output channels can be tuned simultaneously at will by changing the external bias electric field applied to the LC. By analyzing the Fabry-Pérot (FP) resonance modes of the finite-length MIM waveguide both theoretically and numerically, the locations of the three channels are delicately determined to achieve the best demultiplexing effects. Terahertz (THz) signals input from the main channel can be demultiplexed by channels 1, 2 and 3 at 0.7135 THz, 1.068 THz and 1.429 THz, respectively. By applying an external electric field to alter the tilt angle of the infiltrating LC material, the operating frequencies of channels 1, 2 and 3 can be relatively shifted up to 12.3%, 9.6% and 9.7%, respectively. The designed demultiplexer can not only provide a flexible means to demultiplex signals but also tune operating bands of output channels at the same time.

Molecular Dynamics Studies of Nanotube Growth in a Carbon ARC

1994 ◽  
Vol 359 ◽  
Author(s):  
C. J. Brabec ◽  
A. Maiti ◽  
C. Roland ◽  
J. Bernholc
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Electric Fields ◽  
Arc Discharge ◽  
Critical Diameter ◽  
Critical Factor ◽  
Carbon Arc ◽  
Dynamics Simulations ◽  
Nanotube Growth ◽  
Brenner Potential

ABSTRACTIt has been shown experimentally that the growth of carbon nanotubes in an arc discharge is open-ended. This is surprising, because dangling bonds at the end of open tubes make the closed tube geometry more favorable energetically. Recently, it has been proposed that the large electric fields present at the tip of tube is the critical factor that keeps the tube open. We have studied the effects of the electric field on the growth of the nanotubes via ab initio molecular dynamics simulations. Surprisingly, it is found that the electric field cannot play a significant role in keeping the tubes open, implying that some other mechanism must be important. Extensive studies of the energetics and simulations of the growth of tubes were performed using a threebody Tersoff-Brenner potential. Our results show that there exists a critical diameter of ∼ 3 nm above which a defect-free growth of a straight tubule is possible. Narrower tubes stabilize configurations with adjacent pentagons that lead to tube-closure and termination of the growth. This explains the absence of tube narrower than 2.2 nm in arc discharge experiments.

Large-screen displays using metal—insulator—metal cathode arrays

2010 ◽  
Vol 18 (12) ◽  
pp. 1127 ◽  
Author(s):  
Toshiaki Kusunoki ◽  
Masakazu Sagawa ◽  
Mutsumi Suzuki ◽  
Etsuko Nishimura ◽  
Mitsuharu Ikeda ◽  
...  
Keyword(s):  
Metal Insulator ◽  
Large Screen ◽  
Metal Insulator Metal ◽  
Metal Cathode

Suppression of Metal-Insulator Transition in VO2 by Electric Field-Induced Oxygen Vacancy Formation

Science ◽  
2013 ◽  
Vol 339 (6126) ◽  
pp. 1402-1405 ◽  
Author(s):  
J. Jeong ◽  
N. Aetukuri ◽  
T. Graf ◽  
T. D. Schladt ◽  
M. G. Samant ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Electric Field ◽  
Insulator Transition ◽  
Vacancy Formation ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Oxygen Vacancy Formation
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