3. Note on the Rate of Decrease of Electric Conductivity with Increase of Temperature

1875 ◽  
Vol 8 ◽  
pp. 33-34
Author(s):  
D. H. Marshall
Keyword(s):  
Electric Conductivity ◽  
Boiling Point ◽  
Pure Metal ◽  
Absolute Temperature ◽  
Electric Resistance ◽  
Rate Of Increase

These experiments were undertaken in order to determine how closely the hypothesis “that the electric resistance in a pure metal is directly as its absolute temperature” holds for various metals at two easily ascertained temperatures,—that of the air in the room, and the boiling point of water. The apparatus used was a Wheatstone's bridge; one coil of wire kept in a vessel of water at the temperature of the air in the room being put against another, which could be heated up to 100° C. The experiments showed that the rate of increase of resistance with temperature was different for hard and soft specimens of the same metal, being always less in the hard.

A Study on Thermal and Electrical Conductivities of Ethylene-Butene Copolymer Composites with Carbon Fibers

2021 ◽  
Vol 36 (4) ◽  
pp. 417-422
Author(s):  
Y. Hamid ◽  
P. Svoboda
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Carbon Fiber ◽  
Electric Conductivity ◽  
Carbon Fibers ◽  
Mechanical Strain ◽  
Electric Resistance ◽  
Resistance Change ◽  
Electrical Conductivities ◽  
Fiber Sample

Abstract Ethylene-butene copolymer (EBC)/carbon-fiber (CF) composites can be utilized as an electromechanical material due to their ability to change electric resistance with mechanical strain. The electro-mechanical properties and thermal conductivity of ethylene butene copolymer (EBC) composites with carbon fibers were studied. Carbon fibers were introduced to EBC with various concentrations (5 to 25 wt%). The results showed that carbon fibers’ addition to EBC improves the electric conductivity up to 10 times. Increasing the load up to 2.9 MPa will raise the electric resistance change by 4 500% for a 25% fiber sample. It is also noted that the EBC/CF composites’ electric resistance underwent a dramatic increase in raising the strain. For example, the resistance change was around 13 times higher at 15% strain compared to 5% strain. The thermal conductivity tests showed that the addition of carbon fibers increases the thermal conductivity by 40%, from 0.19 to 0.27 Wm–1K–1.

scholarly journals Bakerian lecture.—The nadir of temperature, and allied problems. 1. Physical properties of liquid and solid hydrogen. 2. Separation of free hydrogen and other gases from air. 3. Electric resistance thermometry at the boiling point of hydrogen. 4. Experiments on the liquefaction of helium at the melting point of hydrogen. 5. Pyro-electricity, phosphorescence, &c

1901 ◽  
Vol 68 (442-450) ◽  
pp. 360-366 ◽  
Keyword(s):  
Melting Point ◽  
Physical Properties ◽  
Boiling Point ◽  
Solid Hydrogen ◽  
Hydrogen Gas ◽  
Electric Resistance ◽  
Free Hydrogen ◽  
Resistance Thermometry

Details are given in this paper which have led to the following results:— The helium thermometer which records 20º·5 absolute as the boiling point of hydrogen, gives as the melting point 16° absolute. This value does not differ greatly from the value previously deduced from the use of hydrogen gas thermometers, viz., 16º·7.

scholarly journals 5. On Saturated Vapours

1866 ◽  
Vol 5 ◽  
pp. 449-451
Author(s):  
W. J. Macquorn Rankine
Keyword(s):  
Boiling Point ◽  
Absolute Temperature ◽  
Absolute Zero ◽  
Read Aloud ◽  
Saturated Vapour ◽  
Image Position

As this paper consists almost wholly of formulæ, calculations, and tables, it is not suited for being read to a meeting; and therefore the following short abstract of its contents is alone offered for the purpose of being read aloud :—In the “Edinburgh Philosophical Journal” for July 1849, the author proposed the following formula forthe pressure of saturated vapour corresponding to a given boiling point:—where t is the absolute temperature, reckoned from the absolute zero; and A, B, and C are three specific constants, to be determined from at least three experiments on each substance; and he showed that the results of that formula agreed better with experiment than those of any other formula containing three constants only.

The Influence of Storage Conditions on the Electric Conductivity of Concrete

2019 ◽  
Vol 968 ◽  
pp. 50-60
Author(s):  
Andrii A. Plugin ◽  
Oleksii Pluhin ◽  
Olga Borziak ◽  
Olena Kaliuzhna
Keyword(s):  
Reinforced Concrete ◽  
Electric Conductivity ◽  
Storage Conditions ◽  
Research Data ◽  
Experimental Investigations ◽  
Electric Resistance ◽  
Objective Information ◽  
Moisture Treatment ◽  
Specific Electric Resistance

Theoretical and experimental investigations of the influence of concrete moisture, its age, holding conditions after its thermal moisture treatment and other factors on the specific electric resistance of the concrete of a C32/40 grade used for reinforced concrete sleepers have been carried out. The obtained research data allowed us to specify holding modes and the duration of them and these enable the generation of objective information on the specific electric resistance of the concrete used for the sleepers during their operation.

III. On the effect of the presence of metals and metalloids upon the electric conductivity of pure copper

1860 ◽  
Vol 10 ◽  
pp. 460-460
Keyword(s):  
Electric Conductivity ◽  
Pure Copper ◽  
Pure Metal ◽  
Metals And Metalloids ◽  
Better Than

After studying the effect of suboxide of copper, phosphorus, arsenic, sulphur, carbon, tin, zinc, iron, lead, silver, gold, &c., on the conducting power of pure copper, we have come to the conclusion that there is no alloy of copper which conducts electricity better than the pure metal .

scholarly journals On the Measurement of Electric Resistance of Liquid Electrolytes of Accumulator Battery

2018 ◽  
Vol 61 (6) ◽  
pp. 494-507 ◽  
Author(s):  
N. N. Grinchik ◽  
K. V. Dobrego ◽  
M. A. Chumachenko
Keyword(s):  
Electric Conductivity ◽  
Low Frequency ◽  
Electric Resistance ◽  
Specific Electric Conductivity ◽  
Measuring Device ◽  
Liquid Electrolytes ◽  
Electrochemical Technology ◽  
Accumulator Battery ◽  
Control Of Parameters ◽  
Physical And Chemical

Operational control of parameters of electrolytes (first of all–of specific electric conductivity), is an important electrochemical technology. The methods of measurement of electric conductivity of electrolytes is a subject of permanent discussions because of complexity of physical-and-chemical processes accompanying ion transport and of electrolyte polarization near surfaces of electrodes and of electrochemical processes on the electrodes surfaces. Actual highand low-frequency conductometric methods require relatively expensive equipment and are not free of methodological flaws. In this paper a new method of electric resistance of liquid electrolytes is described and substantiated. It is based on automatic performance of a series of measurements of electrolyte resistance at DC, data processing and extrapolation of an appropriate dependence to threshold voltage at measurement cell plates. The character of functions approximating resistance-applied voltage dependence and method of resistance determination are substantiated. The measurements of specific resistance of some electrolytes were performed. The advantages of the proposed method and measuring device are their simplicity, cheapness, reliability and, consequently, wider possibility to utilize it at technological lines and processes, even at such sites of production processes where such a control was impractical earlier. The method can be widely used for express-diagnostics of electrolytes in such areas as electrochemical energy storage, medicine, agriculture, chemical industry, food production.

3. On the Connection between Temperature and Electrical Resistance in the simple Metals

1862 ◽  
Vol 4 ◽  
pp. 168-170
Author(s):  
Balfour Stewart
Keyword(s):  
Electrical Resistance ◽  
Constant Pressure ◽  
Absolute Temperature ◽  
Philosophical Magazine ◽  
Remarkable Similarity ◽  
Rate Of Increase

About a fortnight since I mentioned to Professor Forbes that the resistances of the simple metals to the passage of electricity seemed to be very nearly in proportion to their absolute temperature, this relation being especially manifest for those values of the resistances determined by M. Arndtsen.Professor Forbes informed me that this coincidence had already been observed by Professor Clausius, and that an abstract of his paper was given in the Philosophical Magazine for November last. On referring to Professor Clausius's original paper, it would seem that the coincidence had suggested itself to him as a remarkable similarity occurring between the rate of increase (due to temperature) of the electrical resistance of those metals, and that of the volume of a gas under constant pressure.

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