Influence of carbon nano-tubes adding on electric conductivity and heating of elastomers under electric current flowing

2020 ◽  
pp. 67-78
Author(s):  
A. V. Shchegolkov ◽  
◽  
V. S. Yagubov ◽  
Yu. A. Khan ◽  
F. F. Komarov ◽  
...  
Keyword(s):  
Electric Conductivity ◽  
Electric Current ◽  
Carbon Nano Tubes

scholarly journals Electric Currents Connected With the Proton Flares of 7 July and 2 September, 1966

1971 ◽  
Vol 43 ◽  
pp. 417-421
Author(s):  
A. B. Severny
Keyword(s):  
Active Region ◽  
Field Strength ◽  
Magnetic Flux ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Conductivity ◽  
Electric Current ◽  
Current Density ◽  
High Energy ◽  
Electric Currents

It is observed that the change of the net magnetic flux associated with flares can exceed 1017 Mx/s, which corresponds according to Maxwell's equation to the e.m.f. ∼ 109 V which is specific for the high energy protons generated in flares. It is shown that this value of e.m.f. can hardly be compensated by e.m.f. of inductance which should appear due to the actually measured motions in a flare generating active region. The values of electric field strength thus found, together with measured values of electric current density (from rotH), leads to an electric conductivity which is 103 times smaller than usually adopted.

Convection experiments with electrolytically heated fluid layers

1971 ◽  
Vol 48 (4) ◽  
pp. 703-719 ◽  
Author(s):  
E. W. Schwiderski ◽  
H. J. A. Schwab
Keyword(s):  
Time Dependence ◽  
Temperature Dependence ◽  
Electric Conductivity ◽  
Electric Current ◽  
Convection Flow ◽  
Convection Pattern ◽  
Fluid Layers ◽  
Direction Dependence ◽  
Heated Fluid ◽  
Theory And Experiments

Convection experiments described by Tritton & Zarraga (1967) with electrolytically heated fluid layers were renewed in order to investigate the reported phenomena, which were hitherto unknown and which contradicted a corresponding theory of Roberts. While the apparatus was essentially unchanged, provisions were incorporated to study the possible influence of several flow and equipment parameters on the convection pattern. With the exception of the temperature dependence of the electric conductivity, the new experiments displayed no essential effects of the convection parameters. Experiments with shallow fluid layers revealed a clear co-orientation of the convection flows with the electric current and a strong time dependence of the hexagonal patterns. Experiments with deeper fluid layers exhibited a considerably diminished time and direction dependence of the convection flow, and a significant reduction of the dilation of the cells. Based on these observations, it is concluded that no drastic differences between theory and experiments, and between internal and external heating, exist, provided the heating is sufficiently uniform.

scholarly journals INFLUENCE OF FREQUENCY OF ELECTRIC CURRENT ON ELECTRIC CONDUCTIVITY OF THIN FILMS OF ELECTROLYTES

2018 ◽  
Vol 61 (2) ◽  
pp. 58
Author(s):  
Vladimir G. Nefedov ◽  
Vadim V. Matveev ◽  
Dmytriy G. Korolyanchuk
Keyword(s):  
Thin Films ◽  
Electric Conductivity ◽  
Electric Current ◽  
Bridge Circuit ◽  
Alternating Current ◽  
Specific Electric Conductivity ◽  
Ordered Structures ◽  
Electrode Cell ◽  
Conductivity Of Thin Films ◽  
High Electric Conductivity

In the work the investigations of the effect of abnormally high electric conductivity of surface of the air-electrolyte interface during electrolytic decomposition of water were continued. Experiments were carried out both at alternating current via the bridge circuit and at direct current in the four-electrode cell. Previously, it was shown that in thin air-bordering electrolyte layers specific conductivity measured in the four-electrode cell during electrolysis of water exceeds the corresponding value measured with the bridge circuit for solutions of sodium hydroxide by 1.5 times, for solutions of sulfuric acid by 1.25 times and for solutions of sodium sulfate by 2.5 times. When replacing the gas-liquid interface by the liquid-solid phase one the effect disappears. It was shown that the abnormally high electric conductivity of thin air-bordering electrolyte layers depends on temperature (at 4 °С electric conductivity of 1 mm thick solution layer increases 8-12 times), ion composition, pH (maximum 5 times increase of electric conductivity corresponds to pH of isoelectric point). This allowed suggesting that such effect is caused by tunneling of charge (without mass transfer) through ordered structures on the surface of water - giant heterophase clusters. This mechanism has been called croquet. To check the influence of surface the experiments in 1 mm and 0.1 mm thick layers of electrolyte were conducted. Thin electrolyte films were stabilized by the DC-10 surfactant and the thickness was measured by interferometric methods. It has been shown that specific electric conductivity of thin films increases by 150-250 times in comparison with conductivity of the original electrolyte. This confirmed our assumptions on the nature of the effect of abnormally high electric conductivity of the gas-electrolyte interface during electrochemical generation of uncompensated H+ and/or OH- ions. Surprisingly, it appears that specific electric conductivity of the electrolyte film of thickness below 50 μm as measured at the 10 kHz alternating current is also higher than conductivity measured with the same method in the initial electrolyte volume. The values of electric conductivity of thin electrolyte films measured by different methods were almost identical. It has been suggested that this phenomenon is related to the changed conditions of charging of the double electric layer. To test the hypothesis, the values of specific electric conductivity of 1 mm thick electrolyte layer were measured at changing from 10 kHz to 0.1 Hz frequencies of alternating current. It was shown that the effect of increase in the electric conductivity begins to occur at frequencies up to 1 kHz. Calculations showed that at these frequencies the quantity of electricity transferred to the electrodes is sufficient for charging the double layer and initiation of the Faraday process. Thus, another confirmation that the croquet mechanism of electric conductivity occurs at the two conditions – the electrolytic generation of H+ or OH- ions and the transfer of charges through ordered structures on the surface of water – was found.Forcitation:Nefedov V.G., Matveev V.V., Korolyanchuk D.G. Influence of frequency of electric current on electric conductivity of thin films of electrolytes. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 2. P. 58-64

scholarly journals Electric Conductivity Probes to Study Change in Degree of Saturation - Bench Top Laboratory Tests

2020 ◽  
Vol 195 ◽  
pp. 03016
Author(s):  
Hadi Kazemiroodsari ◽  
Mishac K. Yegian ◽  
Akram N. Alshawabkeh ◽  
Seda Gokyer
Keyword(s):  
Electrical Conductivity ◽  
Electric Conductivity ◽  
Electric Current ◽  
Degree Of Saturation ◽  
Partial Saturation ◽  
Ottawa Sand ◽  
Initial Concentration ◽  
Archie’S Law ◽  
Sodium Percarbonate ◽  
Liquefaction Susceptibility

Sand characteristics such as liquefaction susceptibility can be affected as a result of change in degree of saturation of sand. New liquefaction mitigation technique by inducing partial saturation in sands is introduced by Yegian et al in 2007[1]. This technique requires to monitor changes in degree of saturation of sand. By nature, changes in degree of saturation of sand can lead in changes in its electric conductivity. Electric conductivity is the property of a material that represents its ability to conduct electric current. Fully saturated sand can conduct electric current better than sand with lower degree of saturation. Therefore, the change in measured electric conductivity can be used to calculate the change in degree of saturation of sand. In 1942, Gus Archie [2] expressed that the electric conductivity of soil is a function of its porosity, degree of saturation, tortuosity and electric conductivity of pore fluid. Using Archie’s law electrical conductivity can be related to the degree of saturation in sands. Typically, electric conductivity probes and meters are instruments which are used to measure electric conductivity. Using electrical conductivity probes, sets of bench top tests were conducted on Ottawa sand to study the relation between degree of saturation and electric conductivity in sand. Partial saturation in sands were created by pouring dry sand into sodium percarbonate solution with a known initial concentration. By nature, sodium percarbonate in water, generates oxygen gas bubbles in time. The changes in electric conductivity in the specimen were measured using electric conductivity meters and probes. In addition, changes in degree of saturation of the specimen were measured using soil phase relations equations. Measured electric conductivity data and calculated degree of saturations were correlated to explore relation between electric conductivity and degree of saturation. This paper presents results of bench top tests, and suggests a relationship between, final degree of saturation of sand and initial concentration of sodium percarbonate solution

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