Effect of Transverse Magnetization on the Resistance of Nickel at High Temperatures

1906 ◽  
Vol 25 (1) ◽  
pp. 292-294
Author(s):  
C. G. Knott
Keyword(s):  
Transverse Magnetization ◽  
Nickel Wire ◽  
Great Care ◽  
Final Temperature ◽  
Longitudinal Magnetization ◽  
Resistance Change ◽  
Considerable Difficulty ◽  
Magnetic Action ◽  
Remarkable Result ◽  
The Wire

AbstractIn a previous communication it was pointed out that the effect of transverse magnetization on the resistance of nickel wire was inappreciable in fields below 500 C.G.S. units, thereby differing from the case of longitudinal magnetization, in which the effect was easily measurable in fields below 20. The reason of this is no doubt to be referred to the thinness of the wire in the direction of the magetizing force. To measure the effect of transverse magnetization it was necessary to form a fiat coil and insert it between the poles of a powerful electro-magnet. Considerable difficulty was experienced in winding this coil with interwound asbestos insulation, for great care had to be taken that no part of the wire cut the lines of force obliquely, otherwise there would be a resolved component of longitudinal effect, which in certain cases might altogether mask the effect looked for. The coil used in the final experiments was suitable in all respects. It was coiled between glass plates, the successive coils being separated by threads of asbestos. Round the coil another coil (of Beacon wire) was wound anti-inductively, so that any current passing through it would have no magnetic action upon the nickel wire inside. By varying the current in this external coil I was able to heat the nickel to any desired temperature up to 400° C. In any one experiment the final temperature came to a steady state, and not till this state was reached was it possible to begin the observations on the resistance change. This was measured in the manner already described in my paper on the effect of longitudinal magnetization, and it will suffice meanwhile to call attention to a remarkable result obtained when the temperature approached that at which nickel ceases to be strongly magnetic.

Note on Resistance Change accompanying Transverse Magnetization in Nickel Wire

1904 ◽  
Vol 24 ◽  
pp. 501-504 ◽  
Author(s):  
C. G. Knott ◽  
Peter Ross
Keyword(s):  
Magnetic Field ◽  
Short Note ◽  
Transverse Magnetic ◽  
Transverse Magnetization ◽  
Nickel Wire ◽  
Longitudinal Field ◽  
Similar Form ◽  
Longitudinal Magnetization ◽  
Resistance Change ◽  
Set Up

The following result, which forms a part of a prolonged investigation into the relations existing among the quantities, magnetization, resistance, and temperature of the magnetic metals, seems sufficiently novel to merit a short note. The results for longitudinal magnetization were communicated to the Society on May 4, 1903; and a somewhat similar form of apparatus was set up in order to study the effect of high temperatures upon the connection between transverse magnetization and resistance in nickel wire. The smallness of the effect of resistance in nickel due to a transverse magnetic field, as compared with the effect of a longitudinal field, rendered all attempts to measure it with this form of apparatus quite nugatory. We were compelled to fall back upon the method employed by Kelvin, Goldhammer, and others, and use the air-gap of a fairly powerful electromagnet as the field.

scholarly journals XIX.—Magnetization and Resistance of Nickel Wire at High Temperatures. Part II.

1907 ◽  
Vol 45 (3) ◽  
pp. 547-554
Author(s):  
C. G. Knott
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Electrical Resistance ◽  
British Association ◽  
Nickel Wire ◽  
Present Communication ◽  
Association Meeting ◽  
The Subject ◽  
The Wire

The experiments which form the subject of the present communication were carried out two years ago, and supplement results already published. A brief note of some of the results was read before the Society in June 1904, and was also read before the British Association Meeting at Cambridge in August of the same year.The previous paper discussed the effect of high temperature on the relation between electrical resistance and magnetization when the wire was magnetized longitudinally, that is, in the direction in which the resistance was measured.The present results have to do with the effect of high temperature on the relation between resistance and magnetization when the magnetization was transverse to the direction along which the resistance was measured.

scholarly journals XI. Magnetic qualities of nickel

1888 ◽  
Vol 179 ◽  
pp. 325-332 ◽  
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Permeability ◽  
Nickel Wire ◽  
Longitudinal Stress ◽  
Iron And Steel ◽  
Dissipation Of Energy ◽  
Direct Bearing ◽  
Early Results ◽  
Cyclic Processes ◽  
The Wire

Although determinations of the magnetic permeability of nickel have been made by Rowland and others, there appears to be no published investigation of the effect of cyclic magnetising processes. The study of such processes is interesting not only in its direct bearing on the relation of magnetisation to magnetising force, but indirectly as yielding data from which one may calculate the dissipation of energy that occurs in reversal or other variation of magnetism, in consequence of hysteresis in the relation of magnetisation to magnetising force. Cyclic processes have been very fully examined for various kinds of iron and steel, and one object of the following experiments was to obtain information of the same kind with regard to nickel. Another object was to examine the effects of longitudinal stress on the magnetisation of this metal in the same manner as they had been examined in iron by one of the writers. Sir William Thomson’s early results in this subject had shown that, when subjected to longitudinal pull, nickel undergoes much change of magnetism, of a kind opposite to that which ordinarily occurs in iron, and it seemed that a fuller investigation of the effects of stress might be useful. The experiments, with the exception of one group described at the end of this paper, were made with specimens of nickel wire supplied by Messrs. Johnson and Matthey. The wire was 0.068 cm. in diameter, and was supplied in what appeared to be a hard-drawn state, in which its magnetic susceptibility was decidedly less than when the wire was annealed. Its magnetic quality was examined both when in this hard-drawn state and after annealing. The direct magnetometric method was employed, in the same manner as in the experiments on iron referred to above.

IX.—On Some Relations between Magnetism and Twist in Iron and Nickel. Part I

1890 ◽  
Vol 35 (2) ◽  
pp. 377-390 ◽  
Author(s):  
Cargill G. Knott
Keyword(s):  
Electric Current ◽  
Nickel Wire ◽  
Ceteris Paribus ◽  
Iron Wire ◽  
Left Handed ◽  
The Wire

In a former paper I described certain experiments on the relations of magnetism and twist in iron and nickel, the chief results of which it may be well to give briefly here. When an iron or nickel wire is under the influence of longitudinal and circular magnetisations, it twists in a direction which is definitely related to the direction of the magnetising forces. This effect in iron was discovered by Wiedemann, and for convenience I shall call it the Wiedemann Effect. It was pointed out by Clerk Maxwell that the Wiedemann effect might be explained as a consequence of the earlier discovery made by Joule, that iron lengthens in the direction of magnetisation, and contracts at right angles thereto. Led by a consideration of Barrett's discovery of the shortening of nickel wire in the direction of magnetisation, I determined to test nickel in the same way in which Wiedemann had tested iron. It was quite obvious that, if Maxwell's explanation of the Wiedemann effect were the true one, nickel wire should, ceteris paribus, twist in a sense opposite to that in which iron twists. The experiment when made completely fulfilled the expectation. Thus, when an iron wire, with one end fixed, is traversed by an electric current in the direction in which it is at the same time longitudinally magnetised, the wire is twisted so that the free end rotates right-handedly with reference to the traversing current, or the longitudinal magnetisation. In nickel, on the contrary, the corresponding rotation is left-handed. This was the chief conclusion arrived at in my earlier paper; and a little consideration will show how very readily the Wiedemann effect, whether in iron or in nickel, is explained in terms of the simpler strains studied by Joule and Barrett.

scholarly journals I. On the influence of temperature on the electric conducting power of metals

1862 ◽  
Vol 152 ◽  
pp. 1-27 ◽  
Keyword(s):  
Pure Metal ◽  
Great Accuracy ◽  
Great Care ◽  
Influence Of Temperature ◽  
Electric Conducting ◽  
Influence Of Temperature On ◽  
Pure Metals ◽  
The Wire ◽  
First Time

The results obtained by different observers in their researches on the influence of temperature on the electric conducting power of metals do not agree at all together. The differences in their results may be partly owing to their not having tested pure metals, and partly to their not having taken into consideration the fact that, when a wire of a pure metal is heated for the first time to 100°C., an alteration in the conducting power of the wire is observed on its again being cooled; in fact, it is necessary to keep the wire for several days at 100° before its conducting power, on again being cooled, becomes constant. In the experiments we are about to detail we have taken great care to employ only pure metals, as well as a method and a disposition of the apparatus with which great accuracy could be obtained.

Synthesis of Cubic Ni Nanoparticles by Electric Current Heating Method Using Ni Wire

2012 ◽  
Vol 512-515 ◽  
pp. 132-135
Author(s):  
Ikuhisa Tada ◽  
Tomoichiro Okamoto ◽  
Yuichiro Kuroki ◽  
Takumi Hagizawa ◽  
Keiichiro Oh-Ishi ◽  
...  
Keyword(s):  
Thin Films ◽  
Electric Current ◽  
Glass Substrate ◽  
Oxygen Atmosphere ◽  
Starting Material ◽  
Nickel Wire ◽  
Ni Nanoparticles ◽  
Heating Method ◽  
Peak Intensity ◽  
The Wire

Nickel wire was used as a starting material to fabricate Ni nanoparticles. A glass substrate was placed above the wire to deposit the particles. The wire was heated by applying a d. c. voltage in the range of 2.2 ~ 4.0 V in oxygen atmosphere until the wire broke. White deposits were observed on the substrate after the heating. The TEM observation revealed that the deposits consisted of cubic nanoparticles with the edge lengths of 2 ~ 200 nm. The size of the particle tended to decrease with decreasing voltage. The particles were covered with films of approximately 4 nm in thickness. After reducing in hydrogen at 250°C for 30 min, the thickness of the films on the cubic particles decreased and the XRD peak intensity attributed to NiO decreased. Consequently the particles were found to be cubic Ni nanoparticles covered with NiO thin films.

Vacuum Gripper System Based on Bistable SMA Actuation

2018 ◽  
Author(s):  
Felix Welsch ◽  
Susanne-Marie Kirsch ◽  
Paul Motzki ◽  
Marvin Schmidt ◽  
Stefan Seelecke
Keyword(s):  
Energy Efficient ◽  
Supply Voltage ◽  
Integrated Design ◽  
Electrical Energy ◽  
Actual State ◽  
Additional Energy ◽  
Resistance Change ◽  
Vacuum Suction ◽  
Suction Cup ◽  
The Wire

This paper presents the design and the realization of an innovative SMA actuated bistable vacuum suction cup. The sealed, compact and fully integrated design enables the positioning and transport of inherent stable components in mobile and stationary applications. The bistable actuator mechanism based on SMA wires combined with a bistable spring represent an energy-efficient, noiseless gripping system without the need for compressed air. Additionally, the self-sensing effect of the SMA enables a sensorless condition-monitoring and energy-efficient control. The mechanics consists of antagonistic SMA wires, which are laterally arranged and connected to the bistable spring via levers. The membrane is directly connected to the bistable spring. The actuation of the wires leads to a rotational movement of the levers thus changes the state of the bistable spring, which directly deforms the membrane. When the membrane is sealed connected to the workpiece, the deformation of the membrane generates a vacuum. The integrated microcontroller electronics manages the joule heating of the wires by measuring the transmitted electrical energy. By applying an electrical energy to the pre-strained SMA wire, the wire heats up and contracts due to the phase transformation from martensite to austenite. The contraction of the wire is accompanied by a significant change in electrical resistance, which enables a resistance based strain feedback. The integrated electronics is able to correlate this resistance change to the actual state of the bistable spring, which leads to a position feedback of the membrane. This allows an adequate electrical energy deposition in the SMA wire by turning-off the heating directly after the position toggle of the membrane. Thereby, a successful position toggle is ensured independent from the ambient temperature and the real supply voltage. The new position of the membrane is then held by the bistable spring without the use of additional energy. This concept leads to a reliable gripping system with fast actuation times.

VII.—The Axial Inclination of Curves of Thermoelectric Force: a Case from the Thermoelectrics of Strained Wires

1914 ◽  
Vol 34 ◽  
pp. 64-68
Author(s):  
John McWhan
Keyword(s):  
Thermoelectric Properties ◽  
Small Angle ◽  
Royal Society ◽  
Pure Metal ◽  
The Other ◽  
Great Care ◽  
Remarkable Result ◽  
Longitudinal Tension ◽  
Metal Wires

In a communication to the Royal Society of Edinburgh, Mr J. D. Hamilton Dickson has examined with great care the valuable results of Professors Dewar and Fleming on the thermoelectromotive forces of various couples, and has come to the conclusion that the curve representing the thermo E.M.F. is in every case a parabola whose axis is, not vertical as had always been assumed, but inclined a definite though very small angle to the E.M.F.-axis.This remarkable result has led me to go back to some experiments which I made a few years ago on the thermoelectric properties of longitudinally strained metal wires, to see if by any chance the same phenomenon might be detected there, and in one instance (only) I have been able to establish its existence unmistakably. The experiments in question, which I have described elsewhere,† were made on couples consisting each entirely of one and the same pure metal; but one wire of the couple might be subjected to any desired longitudinal tension while the other remained unstrained. The temperatures of the junctions were the same in all the experiments, one junction being steam-heated, the other water-cooled.

Microstructural Development in Nb-Ti Multifilamentary Superconductors During Processing

1985 ◽  
Vol 43 ◽  
pp. 190-191
Author(s):  
A. W. West
Keyword(s):  
Heat Treatment ◽  
Critical Current Density ◽  
Copper Matrix ◽  
Wire Drawing ◽  
Heat Treatments ◽  
Microstructural Development ◽  
Final Size ◽  
Density Values ◽  
The Wire ◽  
Multifilamentary Superconductors

The influence of the filament microstructure on the critical current density values, Jc, of Nb-Ti multifilamentary superconducting composites has been well documented. However the development of these microstructures during composite processing is still under investigation.During manufacture, the multifilamentary composite is given several heat treatments interspersed in the wire-drawing schedule. Typically, these heat treatments are for 5 to 80 hours at temperatures between 523 and 573K. A short heat treatment of approximately 3 hours at 573K is usually given to the wire at final size. Originally this heat treatment was given to soften the copper matrix, but recent work has shown that it can markedly change both the Jc value and microstructure of the composite.

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