Without elasticity of dimensions, it is also without known counterpart.
But their most characteristic, though not perhaps their most general, property is that they combine in themselves the apparently incompatible properties of elasticity and rigidity on the one hand and plasticity on the other.
When caoutchouc is heated slightly above the temperature of boiling water it becomes softer and loses much of its elasticity, which, however, it recoveres on cooling.
It thus appears that if the amplitude of vibration could be as much as 1 o_2 of the wave-length, the aether would be an excessively rare medium with very slight elasticity; and yet it would be capable of transmitting the supply of solar energy on which all terrestrial activity depends.
The Latin Church, which, by combining the tradition of the Roman centralized organization with a great elasticity in practice and in the interpretation of doctrine, had hitherto been the moulding force of civilization in the West, is henceforth more or less in antagonism to that civilization, which advances in all its branches - in science, in literature, in art - to a greater or less degree outside of and in spite of her, until in its ultimate and most characteristic developments it falls under the formal condemnation of the pope, formulated in the famous Syllabus of 1864.
Its physical properties, permeability by water, extensibility and elasticity, receive their interpretation in the needs of the latter.
For example, the physicist determines the density, elasticity, hardness, electrical and thermal conductivity, thermal expansion, &c.; the chemist, on the other hand, investigates changes in composition, such as may be effected by an electric current, by heat, or when two or more substances are mixed.
For the subjects of this general heading see the articles Mechanics; Dynamics, Analytical; Gyroscope; Harmonic Analysis; Wave; HYDROMechanics; Elasticity; Motion, Laws Of; Energy; Energetics; Astronomy (Celestial Mechanics); Tide.
The development of the rubber industry has now reached a stage at which more exact methods of determining the chemical composition and physical properties (strength and elasticity) of rubber are required.
- The micas are characterized by a very easy cleavage in a single direction and by the high degree of flexibility, elasticity and toughness of the extremely thin cleavage flakes.
Miscellaneous Effects of Magnetization: Electric Conductivity - Hall Effect - Electro-Thermal Relations - Thermoelectric Quality - Elasticity - Chemical and Voltaic Effects.
The dimensions of a piece of iron, for example, its elasticity, its thermo-electric power and its electric conductivity are all changed under the influence of magnetism.
An experiment by Ewing showed that by the operation of stretching an annealed iron wire beyond the limits of elasticity the permeability under a magnetizing force of about 3 units was reduced by as much as 75%.
The width of the gap may be diminished until it is no greater than the distance between two neighbouring molecules, when it will cease to be distinguishable, but, assuming the molecular theory of magnetism to be true, the above statement will still hold good for the intermolecular gap. The same pressure P will be exerted across any imaginary section of a magnetized rod, the stress being sustained by the intermolecular springs, whatever their physical nature may be, to which the elasticity of the metal is due.
Changes of elasticity are in all cases dependent, not only upon the field, but also upon the tension applied; and, owing to hysteresis, the results are not in general the same when the magnetization follows as when it precedes the application of stress; the latter is held to be the right order.
This condition manifests itself, for example, in mine pillars which are subjected to a weight beyond the limit of elasticity of the mineral of which they are composed.
Per metre, which, for practical purposes, Wertheim takes as giving the limit of elasticity; column 4 gives the breaking strain.
Such an alloy can be cast like ordinary bronze, but excels the latter in hardness, elasticity, toughness and tensile strength.
Most metals when molten are capable of dissolving at least small proportions of carbon, which, in general, leads to a deterioration in metallicity, except in the case of iron, which by the addition of small percentages of carbon gains in elasticity and tensile strength with little loss of plasticity.
On another physical assumption of constant cubical elasticity A, dp = Ad p /P, (p - po)IA= lo g (P/Po), (18) dp _ A dp (I 1 zd p dz - P ' A Po-p -z, I - p -k, A kPo ' (19) (3) P dx Pdy Pdz -., (I) When the density p is f un dp/ iform, this becomes, as before in (2) § 9 P pp ==Pzz++pao constant.
Other tests show variability in burning quality, elasticity of leaf, texture, taste, &c. The United States Department of Agriculture has closely investigated this important question and the results attained are brought together by Messrs H.
The timber is specially valued for furniture and cabinet work and for gunstocks, the beauty of its markings rendering it desirable for the first-named purpose, while its strength and elasticity fit it for the second.
If we write K for the adiabatic elasticity, and k for the isothermal elasticity, we obtain S/s = ECÃ†F = K/k.
The isothermal elasticity - v(dp/dv) is equal to the pressure p. The adiabatic elasticity is equal to y p, where -y is the ratio S/s of the specific heats.
For concrete the coefficient of elasticity E varies with the amount of stress and diminishes as the ratio of sand and stone to cement increases.
On being relieved from picket duty Rostov had managed to get a few hours' sleep before morning and felt cheerful, bold, and resolute, with elasticity of movement, faith in his good fortune, and generally in that state of mind which makes everything seem possible, pleasant, and easy.
In the dead animal, and for its great elasticity and power of muscular contraction while living.
But experience soon proved the superiority of the spider web; its perfection of shape, its lightness and elasticity, have led to its universal adoption.
The following branches have especially felt his influence: - chemical physics, capillarity and viscosity, theory of gases, flow of liquids, photography, optics, colour vision, wave theory, electric and magnetic problems, electrical measurements, elasticity, sound and hydrodynamics.
One of the great evils of Italian agricultural taxation is its lack of elasticity and of adaptation to local conditions.
The remark may conveniently find its place here that plants which have reached a high degree of adaptive specialization have come to the end of their tether: a too complicated adjustment has deprived them of the elasticity which would enable them to adapt themselves to any further change in their surroundings, and they would pass away with conditions with which they are too inextricably bound up. Vast floras have doubtless thus found their grave in geologic change.
The foregoing experiments indeed, in some measure, decided this point, as much the greatest part of air let up into the tube lost its elasticity; yet, as some remained unabsorbed, it did not appear for certain whether that was of the same nature as the rest or not.
Light is therefore an influence propagated as wave-motion, and moreover by transverse undulations, for the reasons brought out by Thomas Young and Augustin Fresnel; so that the aether is a medium which possesses elasticity of a type analogous to rigidity.
Let E be the effective elasticity of the aether; then E = pc t, where p is its density, and c the velocity of light which is 3 X 10 10 cm./sec. If = A cos" (t - x/c) is the linear vibration, the stress is E dE/dx; and the total energy, which is twice the kinetic energy Zp(d/dt) 2 dx, is 2pn2A2 per cm., which is thus equal to 1.8 ergs as above.
The idea of MacCullagh's aether, and its property of purely rotational elasticity which had been expounded objectively by W.
The energy of this fork with a given amplitude of vibration could be calculated from its dimensions and elasticity, and the amplitude was observed by measuring with a microscope the line into which the image of a starch grain on the prong was drawn by the vibration.
If y is the displacement at A, and if E is the elasticity, substituting for w and u from (2) and (3) we get X - Ed x d +pU2 But since the volume dx with density po has become volume dx+dy with density p p (d = po.
It may be noted that the elasticity E is only constant for small volume changes or for small values of dy/dx.
When a wave of sound travelling through one medium meets a second medium of a different kind, the vibrations of its own particles are communicated to the particles of the new medium, so that a wave is excited in the latter, and is propagated through it with a velocity dependent on the density and elasticity of the second medium, and therefore differing in general from the previous velocity.
An unfinished work, The History of the Theory of Elasticity, was edited and published posthumously in 1886 by Karl Pearson.
In thiscase the ratio of the specific heats is constant as well as the difference, and the adiabatic equation takes the simple form, pv v = constant, which is at once obtained by integrating the equation for the adiabatic elasticity, - v(dp/dv) =yp.
Strains exceeding the "limit of elasticity" result in permanent deformation or (if sufficiently great) in rupture.