Special Government Standard of unit alternating current within the 40?1�105-Hz frequency range

1976 ◽  
Vol 19 (3) ◽  
pp. 384-386
Author(s):  
O. P. Galakhova ◽  
E. K. Dranishnikova ◽  
M. S. Belyaeva
Keyword(s):  
Alternating Current ◽  
Frequency Range ◽  
Government Standard ◽  
Special Government Standard

Special Government Standard of unit alternating voltage within the 20?3�107-Hz frequency range

1976 ◽  
Vol 19 (3) ◽  
pp. 387-390 ◽  
Author(s):  
T. B. Rozhdestvenskaya ◽  
R. F. Aknaev ◽  
O. P. Galakhova
Keyword(s):  
Frequency Range ◽  
Government Standard ◽  
Special Government Standard ◽  
Alternating Voltage

Special Government Standard of unit electric field intensity within frequency range 30?1000 MHz

1976 ◽  
Vol 19 (3) ◽  
pp. 391-392
Author(s):  
G. M. Belyakova ◽  
V. S. Buzinov ◽  
M. E. Melekhov ◽  
V. A. Tishchenko ◽  
A. N. Filonov
Keyword(s):  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Frequency Range ◽  
Government Standard ◽  
Special Government Standard

scholarly journals ELECTRIC IMPEDANCE OF SINGLE MARINE EGGS

1938 ◽  
Vol 21 (5) ◽  
pp. 591-599 ◽  
Author(s):  
Kenneth S. Cole ◽  
Howard J. Curtis
Keyword(s):  
Preliminary Data ◽  
Sea Water ◽  
Membrane Conductance ◽  
Glass Tube ◽  
Alternating Current ◽  
Electric Impedance ◽  
Frequency Range ◽  
Impedance Measurements ◽  
Membrane Capacity ◽  
Thin Walled

Alternating current impedance measurements have been made on several single marine eggs over the frequency range from 1 to 2500 kilocycles per second. The eggs were placed in the center of a short capillary made by heating the end of a 2 mm. thin walled glass tube until it nearly closed, and electrodes were placed in the sea water on each side of the egg. When it is assumed that the membrane conductance is negligible, the membrane capacity and internal resistances of unfertilized and fertilized Arbacia eggs agree with the values obtained from suspensions. Preliminary data on centrifugally separated half Arbacia eggs, and whole Cumingia and Chaetopterus eggs are given.

ESTIMATION OF ERROR IN MEASURING THE DEPTH OF SURFACE CRACKS BY THE ELECTROPOTENTIAL METHOD ON AN ALTERNATING CURRENT

2020 ◽  
pp. 36-46
Author(s):  
P. N. Shkatov ◽  
I. G. Kuzub ◽  
A. A. Ermolaev
Keyword(s):  
Test Sample ◽  
Alternating Current ◽  
Electromagnetic Properties ◽  
Specific Electrical Conductivity ◽  
Measuring Error ◽  
Surface Cracks ◽  
Frequency Range ◽  
Estimation Of Error ◽  
The Difference ◽  
Free Area

The study carried out research on the error in measuring the depth of surface cracks by the electropotential method on an alternating current with a variation in the magnetic permeability and specific electrical conductivity of the metal. The measuring error appear from the difference between the electromagnetic properties of the metal of the sample used to obtain the calibration dependences and the properties of the metal of the tested object. The research conducted by the method of the finite element. The analysis of the dependences of the electropotential signal in the frequency range for the defect-free area and the area with a surface crack is carried out. The study of the error in measuring the depth h, that depends on the frequency of the transmitted current and the value of h. The comparison of the errors arising from various methods of choosing the calibration characteristics is performed, including the comparison of the equality of electropotential signals in the defect-free areas of the tested area and the test sample selected for calibration.

Results of tests on the indicator of external noise of electric locomotives in the standing time

2017 ◽  
Vol 76 (5) ◽  
pp. 301-305 ◽  
Author(s):  
M. Yu. Noskov ◽  
M. M. Ginshparg ◽  
N. S. Nesterov
Keyword(s):  
Spectral Composition ◽  
Sound Field ◽  
Alternating Current ◽  
External Noise ◽  
Stationary Mode ◽  
Frequency Range ◽  
Electric Locomotive ◽  
Standing Time ◽  
Test Loop ◽  
Absorbing Material

The authors of the Test Loop of the JSC “VNIIZhT” had conducted tests of mainline electric locomotives intended for handling freight trains on sections of the road electrified with alternating current at a voltage of 25 kV (electric locomotives of an alternating current). Tests were conducted in terms of the level of external noise at the standing time. The results of tests of AC electric locomotive, which was in a stationary mode, are presented in terms of the external noise index, and a methodology for performing these tests is described. As a result of the conducted researches, the article establish the main sources of external noise in the operation of AC electric locomotives (fans intended for cooling electrical equipment and traction motors, air compressors, traction transformers, etc.), its actual values, as well as the nature of the sound field around electric locomotives. The analysis of the obtained sound field made it possible to identify the points where the excess of the standard noise values (more than 65 dBA) is observed. It is proposed to bring the technical condition of the equipment, such as traction transformer, converter and cooling module of the traction engine of the power compartment of an electric locomotive in accordance with the normative documentation. The repeated measurements of the external noise level after technical completion did not reveal the excess of its normative values in accordance with the regulatory documentation. In order to provide a normative margin in terms of the external noise of an electric locomotive, it is proposed to use sound-absorbing material in the construction of its body. It is recommended to perform an experimental study of the spectral composition of the noise of the equipment of an electric locomotive operating at the standing time and the resulting external noise at points located outside and around the locomotive in order to calculate the acoustic characteristics of sound-absorbing materials. Sound absorbing material is expedient to be selected depending on the frequency range in which the greatest excess is observed above the maximum permissible values using known empirical and semi-empirical dependences, on the basis of which it is possible to preliminary determine its sound-absorbing properties in the frequency range established by regulatory documents. After equipping the power compartment of the locomotive with soundproof materials, tests on the evaluation of the external noise of an electric locomotive at standing should be repeated.

scholarly journals TRANSVERSE ELECTRIC IMPEDANCE OF NITELLA

1937 ◽  
Vol 21 (2) ◽  
pp. 189-201 ◽  
Author(s):  
Howard J. Curtis ◽  
Kenneth S. Cole
Keyword(s):  
Cell Membrane ◽  
Phase Angle ◽  
Current Flow ◽  
Transverse Electric ◽  
Specific Resistance ◽  
Alternating Current ◽  
Living Cells ◽  
Electric Impedance ◽  
Frequency Range ◽  
Mature Cell

Alternating current measurements have been taken on single Nitella cells over a frequency range from 30 to 2,500,000 cycles per second with the current flow perpendicular to the axis of the cell. The measuring cells were so constructed that electrolytes of any desired concentration could be circulated during the course of the measurements. The cellulose wall which surrounds the cell is found to play an important part in the interpretation of the results obtained. In a mature cell, this cellulose has a specific resistance of about 1000 ohm cm. which is independent of the medium in which the cell is suspended. The thickness of the wall is computed to be about 10 µ. The cell membrane is found to be virtually non-conducting, and to have a capacity of 0.94 µf./cm.2 ± 10 per cent and a phase angle of 80° ± 4°. The specific resistances of the sap were difficult to compute from data on living cells and were unsatisfactory because they were very much dependent upon the medium, while measurements on extracted sap gave 58 ohm cm. ± 8 per cent which was independent of the medium. There are indications that the chloroplasts have impedance properties similar to those of living cells.

Special Government Standard of unit magnetic induction over the 2.0?10-T range

1976 ◽  
Vol 19 (3) ◽  
pp. 401-403 ◽  
Author(s):  
G. K. Yagola ◽  
Yu. I. Kazantsev ◽  
V. M. Simonov ◽  
D. I. Cheburkov
Keyword(s):  
Magnetic Induction ◽  
Government Standard ◽  
Special Government Standard
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