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Einstein s laws

Figure 4 demonstrates the results of several investigations. It can be seen that both methods lead to a linear dependence between c and Mw but differ by a factor of ten. The reason is seen in the fact that c ] depends on a model (Einstein s law), whereas c LS gives absolute results. In both cases the geometric shape of the polymer coils are assumed to be spherical but, in accordance with the findings of Kuhn, we know that the most probable form can be best represented as a bean-like (irregularly ellipsoidal) structure. [Pg.13]

Abnormally high quantum yields may occur in photochemical reactions. Einstein s law of photochemical equivalence is the principle that light is absorbed by molecules in discrete amounts as an individual molecular process (i.e., one molecule absorbs one photon at a time). From optical measurements it is possible to determine quantitatively the number of photons absorbed in the course of a reaction and, from analyses of the product mixture, it is possible to determine the number of molecules that have reacted. The quantum yield is defined as the ratio of the number of molecules reacting to the number of photons absorbed. If this quantity exceeds unity, it provides unambiguous evidence for the existence of secondary processes and thus indicates the presence of unstable intermediates. [Pg.96]

Eimco High-Capacity thickener, 22 66 Einsteinium (Es), 1 463-491, 464t electronic configuration, l 474t ion type and color, l 477t metal properties of, l 482t Einstein relation, 22 238. See also Einstein s viscosity equation filled networks and, 22 571, 572 Einstein s coefficient, 14 662 Einstein s equation, 7 280 21 716 23 99 Einstein s law, 19 108 Einstein s viscosity equation, 22 54. [Pg.299]

Einstein s laws of absorption and emission describe the operation of lasers. The luminescence of minerals, considered in this book, is a spontaneous emission where the luminescence is independent of incident radiation. In a stimulated emission the relaxation is accomplished by interaction with a photon of the same energy as the relaxation energy. Thus the quantum state of the excited species and the incident photon are intimately coupled. As a result the incident and the emitted photons will have the same phase and propagation direction. The emitted light of stimulated emission is therefore coherent as opposed to the... [Pg.35]

FIG. 4.9 Experimental verification of Einstein s law of viscosity for spherical particles of several different sizes (Squares are yeast particles, Rs = 2.5 71m circles are fungus spores, Rs = 4.0 /xm triangles are glass spheres, R, = 80 /xm). Open symbols represent measurements in concentric-cylinder viscometers, and closed symbols represent measurements in capillary viscometers. (Data from F. Eirich, M. Bunzl, and H. Margaretha, Kolloid Z., 74, 276 (1936).)... [Pg.164]

In simple instances, therefore, we should expect to find one molecule transformed for each quantum of light absorbed, provided that the light is active at all. This is Einstein s law of photochemical equivalence. [Pg.73]

Deviations from Einstein s law can occur in true photochemical reactions owing to the degradation of the absorbed light energy into thermal energy as a result of collisions with other molecules which the activated molecules suffer before they have a chance to react. This makes the number of quanta absorbed greater than the number of molecules transformed. [Pg.75]

The rate of production of bromine atoms by light is estimated on the basis of Einstein s law, which requires one molecule of bromine to be dissociated for each quantum of light absorbed. In the stationary state the number of bromine atoms recombining thermally in unit time is equal to this rate of photochemical formation. Thus the number of bromine atoms which recombine per second at a known atomic concentration is found. In this way Bodenstein and Liitkemeyer find that about one collision in a thousand between bromine atoms results in combination. This number is of the right order of magnitude only, since the estimation of the number of light quanta absorbed was not very certain, and a value based only on analogy had to be assumed for the diameter of the bromine atom. [Pg.87]

The most direct evidence that negative catalysis sometimes works in this way in ordinary thermal reactions, and, therefore, incidentally that the chain mechanism can operate in such reactions, has been found by Backstrom. In the photochemical oxidation of benzaldehyde, heptalde-hyde, and of solutions of sodium sulphite, there are very large numbers of molecules transformed for each quantum of light absorbed, amounting respectively to 10,000,15,000, and 50,000 for the three reactions. Such deviations from Einstein s law show that the light probably sets up chain reactions. These photochemical changes are markedly subject to the action of inhibitors, which presumably cut short the chains. Backstrom establishes the important... [Pg.170]

NATURE OF NUCLEAR FISSION REACTIONS The energy of a nuclear fission reaction can be computed from the change in mass between reactants and products according to Einstein s law ... [Pg.1101]

As already discussed at the end of Section 2.2.3, we derived a universal superposition principle from a complex symmetric ansatz arriving at a Klein-Gordon-like equation relevant for the theory of special relativity. This approach, which posits a secular-like operator equation in terms of energy and momenta, was adjoined with a conjugate formal operator representation in terms of time and position. As it will be seen, this provides a viable extension to the general theory [7, 82]. We will hence recover Einstein s laws of relativity as construed from the overall global superposition, demonstrating in addition the independent choice of a classical and/or a quantum representation. In this way, decoherence to classical reality seems always possible provided that appropriate operator realizations are made. [Pg.78]

Equation (105) follows Einstein s law of light deflection, i.e., photons are deflected twice than that of Newtonian gravity. [Pg.82]

The diffusion coefficient of a suspended material is related to the frictional coefficient of the particles by Einstein s law of diffusion ... [Pg.25]

Walter Noddack (1893-1960) began studying chemistry, physics and mathematics at the University of Berlin in 1912. Having volunteered during World War I, he received his doctorate in 1920 only, under the direction of Nernst on Einstein s law of photochemical equivalence. He became di-... [Pg.142]

Being able to determine [r ] as a function of elution volume, one can now compare the hydrodynamic volumes Vh for different polymers. The hydrodynamic volume is, through Einstein s viscosity law, related to intrinsic viscosity and molar mass by Vh=[r ]M/2.5. Einstein s law is, strictly speaking, valid only for impenetrable spheres at infinitely low volume fractions of the solute (equivalent to concentration at very low values). However, it can be extended to particles of other shapes, defining the particle radius then as the radius of a hydrody-namically equivalent sphere. In this case Vjj is defined as the molar volume of impenetrable spheres which would have the same frictional properties or enhance viscosity to the same degree as the actual polymer in solution. [Pg.18]

The theoretical efficiency of a separation - as high as one million plates/metre in a column of length L - can be calculated from its effective length I and from the diffusion coefficient D (cm /s). This latest parameter is linked to the dispersion a and to the migration time via Einstein s law (cr = 2D Expression 8.9... [Pg.158]


See other pages where Einstein s laws is mentioned: [Pg.149]    [Pg.149]    [Pg.353]    [Pg.388]    [Pg.164]    [Pg.153]    [Pg.154]    [Pg.266]    [Pg.270]    [Pg.166]    [Pg.142]    [Pg.353]    [Pg.33]    [Pg.78]    [Pg.5]    [Pg.293]    [Pg.4]    [Pg.331]    [Pg.153]    [Pg.154]    [Pg.106]    [Pg.248]    [Pg.388]    [Pg.7]    [Pg.41]    [Pg.60]    [Pg.5]    [Pg.26]   
See also in sourсe #XX -- [ Pg.73 ]

See also in sourсe #XX -- [ Pg.386 ]




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Einsteins Law

Einstein’s diffusion laws

Einstein’s law of photochemical

Einstein’s law of photochemical equivalence

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