scholarly journals Charge vibration behaviour in polyimide under the pulse voltage with different rise and fall times

High Voltage ◽  
2021 ◽  
Author(s):  
Tao Zhang ◽  
Dongxin He ◽  
Junyu Wei ◽  
Hongshun Liu ◽  
Qingquan Li ◽  
...  
Keyword(s):  
Pulse Voltage

Electrochemical reduction of NaBO2 into NaBH4 with pulse voltage using the Eu-Co-Ni-B coating electrode

2020 ◽  
pp. 1-10
Author(s):  
Shimin Zhang ◽  
Biqing Chen ◽  
Lixia Gao ◽  
Tongtong Xiong ◽  
Chan Du ◽  
...  
Keyword(s):  
Electrochemical Reduction ◽  
Pulse Voltage ◽  
Coating Electrode ◽  
The Eu

scholarly journals Block of squid axon K channels by internally and externally applied barium ions.

1982 ◽  
Vol 80 (5) ◽  
pp. 663-682 ◽  
Author(s):  
C M Armstrong ◽  
R P Swenson ◽  
S R Taylor
Keyword(s):  
Time Constant ◽  
Recovery Time ◽  
Pulse Voltage ◽  
Squid Axon ◽  
Barium Ions ◽  
K Channels ◽  
Voltage Dependent ◽  
One Step ◽  
Dissociation Constant Kd ◽  
The Way

We have studied the interactions of Ba ion with K channels. Ba2+ blocks these channels when applied either internally or externally in millimolar concentrations. Periodic depolarizations enhance block with internal Ba2+, but diminish the block caused by external Ba2+. At rest, dissociation of Ba2+ from blocked channels is very slow, as ascertained by infrequent test pulses applied after washing Ba2+ form either inside or outside. The time constant for recovery from internal and external Ba2+ is the same. Frequent pulsing greatly shortens recovery time constant after washing away both Ba2+in and Ba2+out. Block by Ba2+ applied internally or externally is voltage dependent. Internal Ba2+ block behaves like a one-step reaction governed by a dissociation constant (Kd) that decreases e-fold/12 mV increase of pulse voltage: block deepens with more positive pulse voltage. For external Ba2+, Kd decreases e-fold/18 mV as holding potential is made more negative: block deepens with increasing negativity. Millimolar external concentrations of some cations can either lessen (K+) or enhance (NH+4, Cs+) block by external Ba2+. NH+4 apparently enhances block by slowing exist of Ba ions from the channels. Rb+ and Cs+ also slow clearing of Ba ions from channels. We think that (a) internally applied Ba2+ moves all the way through the channels, entering only when activation gates are open; (b) externally applied Ba2+ moves two-thirds of the way in, entering predominantly when activation gates are closed; (c) at a given voltage, Ba2+ occupies the same position in the channels whether it entered from inside or outside.

Lightning protection of the object located on the slope

2021 ◽  
pp. 93-103
Author(s):  
A. A. Kosyakov ◽  
Keyword(s):  
Pulse Voltage ◽  
Lightning Protection ◽  
Engineering Practice ◽  
Protection Device ◽  
Lightning Strikes ◽  
Protection Zones ◽  
Pulse Voltage Generator ◽  
Voltage Generator ◽  
Protected Object

The article points out the drawback of all the current instructions for the lightning protection device: the lack of instructions for calculating the lightning protection zones of an object located on a slope. The methods of applying the current instructions for the lightning protection device when placing an object on a slope are given, based on the assumption that lightning strikes the lightning rods vertically and perpendicular to the slope. The features of the choice of lightning protection characteristics (calculated points of the protected object, calculated heights of lightning rods, methods of constructing lightning protection zones) are described. A method for calculating the lightning protection zones of an object located on a slope is proposed, based on the assumption that lightning strikes lightning rods perpendicular to the slope, in particular, the concept of the axis of a conditional lightning rod shifted on the object plan for calculating lightning protection zones is introduced. The consequences of the application in engineering practice of the methodology for calculating the lightning protection zones of an object located on a slope, based on the assumption that lightning strikes the lightning rods perpendicular to the slope, are indicated. Using a pulse voltage generator, tests were performed on a model of a lightning rod located on a slope in order to determine the direction of lightning strikes-vertical or perpendicular to the slope. It was determined experimentally that the proposed method for calculating the lightning protection zones of an object located on a slope, based on the assumption that lightning strikes lightning rods perpendicular to the slope, should be used in cases where the protected objects are located on slopes with an angle of more than 25°.

Temperature-dependence of L-type Ca(2+) channel current in atrial myocytes from rainbow trout

2000 ◽  
Vol 203 (18) ◽  
pp. 2771-2780 ◽  
Author(s):  
H.A. Shiels ◽  
M. Vornanen ◽  
A.P. Farrell
Keyword(s):  
Rainbow Trout ◽  
Temperature Dependence ◽  
Voltage Clamp ◽  
Pulse Voltage ◽  
Kinetic Properties ◽  
Temperature Dependency ◽  
Atrial Myocytes ◽  
Patch Clamp Technique ◽  
Channel Current ◽  
Series Of Experiments

Rainbow trout, Oncorhynchus mykiss, inhabit eurythermal environments and must therefore be able to cope with changes in environmental temperature. As ectotherms, their heart is required to maintain cardiac function over a range of ambient water temperatures. This raises important questions concerning the temperature-dependence of cardiac ion channel function in fish hearts, in particular, the channels involved in Ca(2+) transport. Thus, we studied the effects of acute, physiologically relevant temperature changes on the density and kinetics of the L-type Ca(2+) channel current (I(Ca)) in rainbow trout atrial myocytes using the whole-cell patch-clamp technique. Myocytes from fish acclimated to 14 degrees C were first tested at 14 degrees C, then at 21 degrees C and finally at 7 degrees C. Using a square-pulse voltage-clamp in the first series of experiments, the peak density of I(Ca) increased (Q(10)=1.9) as temperature was increased from 14 to 21 degrees C and decreased (Q(10)=2.1) as temperature was decreased from 14 to 7 degrees C. In contrast to current density, the charge carried by I(Ca) was inversely related to temperature as a result of changes in the kinetic properties of the channel; both the fast (tau(f)) and slow (tau(s)) components of inactivation were slower at 7 degrees C than at 14 and 21 degrees C. Action potentials were recorded at the three test temperatures and then used as voltage-clamp stimulus waveforms to reassess I(Ca) in a second series of experiments. While the temperature-dependency of I(Ca) was similar to that found with the square-pulse voltage-clamp, the charge carried by I(Ca) was temperature-independent. These results show that the temperature-dependency of I(Ca) in rainbow trout is in the lower range of that reported in mammals and, although this could have profound effects on Ca(2+) delivery to the myofilaments, the temperature-induced modifications in the action potential may help to maintain a fairly constant Ca(2+) delivery during an acute temperature change in rainbow trout.

scholarly journals Pulse voltage determination for electrostatic micro manipulation considering surface conductivity and adhesion of glass particle

AIP Advances ◽  
2015 ◽  
Vol 5 (5) ◽  
pp. 057126 ◽  
Author(s):  
Ryo Fujiwara ◽  
Pasomphone Hemthavy ◽  
Kunio Takahashi ◽  
Shigeki Saito
Keyword(s):  
Glass Particle ◽  
Surface Conductivity ◽  
Pulse Voltage
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