Physical decay

Kramish, A. Spontaneous fission versus alpha decay. Physic. Rev. 88, 1201... 

Hudson, Experimental Test of Parity Conservation in Beta Decay, Physical Review 103, 1413-1414 (1957). 

In this note we summarize the applications of the entropy rate admissibility criterion to the above fluids, discussed in [6], [7], [8], and extend the results in [6], [7]. This criterion, which has been proposed by Dafermos [10], [11] originally for hyperbolic systems of conservation laws, roughly says that the entropy decays (physically increases) with the highest rate for the admissible solution. As mentioned above, the systems we discuss are of hyperbolic-elliptic mixed type. We... 

R. Battiston, D. Cocolicchio, G.L. Fogli, N. Paver. Status and perspectives of K decay physics... 

The adsorption of nonelectrolytes at the solid-solution interface may be viewed in terms of two somewhat different physical pictures. In the first, the adsorption is confined to a monolayer next to the surface, with the implication that succeeding layers are virtually normal bulk solution. The picture is similar to that for the chemisorption of gases (see Chapter XVIII) and arises under the assumption that solute-solid interactions decay very rapidly with distance. Unlike the chemisorption of gases, however, the heat of adsorption from solution is usually small it is more comparable with heats of solution than with chemical bond energies. 

In the second picture, an interfacial layer or region persists over several molecular diameters due to a more slowly decaying interaction potential with the solid (note Section X-7C). This situation would then be more like the physical adsorption of vapors (see Chapter XVII), which become multilayer near the saturation vapor pressure (e.g.. Fig. X-15). Adsorption from solution, from this point of view, corresponds to a partition between bulk and interfacial phases here the Polanyi potential concept may be used (see Sections X-7C, XI-1 A, and XVII-7). 

The difference compared to equation B 1.13.2 or equation B 1.13.3 is the occurrence of the expectation value of the operator (the two-spin order), characterized by its own decay rate pjg and coupled to the one-spin longitudinal operators by the tenus 8j aud 5. We shall come back to the physical origin of these tenus below. 

Figure 7.11 from Alder B J and T E Wainwright 1970. Decay of the Velocity Autocorrelation Function. Physical Review A 1 18-21. 

The slow decay of the velocity autocorrelation function towards zero can be explained in terms of the of a hydrodynamic vortex. (Figure adapted from Alder B J and T E Wainwright 1970. Decay of the Velocity tation Function. Physical Review A 1 18-21.)... 

The various chemical and physical processes that play a role ia the deterioration of art objects are not restricted to the present, even though the contemporary environment has contributed significantly to the rate of decay. Revered masterpieces have lost splendor throughout the ages. Indeed, from textual evidence, it is known how artists ia the Renaissance restored works of art from Classical times. These restorers of past centuries attempted to return the object to its original appearance. The fallacy of that idea Hes ia the fact that they could not know the exact original appearance of the work, ie, immediately after its creation therefore, they restored the object according to their subjective opinions. 

In almost all cases X is unaffected by any changes in the physical and chemical conditions of the radionucHde. However, there are special conditions that can influence X. An example is the decay of Be that occurs by the capture of an atomic electron by the nucleus. Chemical compounds are formed by interactions between the outer electrons of the atoms in the compound, and different compounds have different electron wave functions for these outer electrons. Because Be has only four electrons, the wave functions of the electrons involved in the electron-capture process are influenced by the chemical bonding. The change in the Be decay constant for different compounds has been measured, and the maximum observed change is about 0.2%. 

In spite of these special cases, in all appHed uses the decay constants and half-Hves can be considered to be independent of the physical and chemical environment. 

Because of the presence of an extended polyene chain, the chemical and physical properties of the retinoids and carotenoids are dominated by this feature. Vitamin A and related substances are yellow compounds which are unstable in the presence of oxygen and light. This decay can be accelerated by heat and trace metals. Retinol is stable to base but is subject to acid-cataly2ed dehydration in the presence of dilute acids to yield anhydrovitamin A [1224-18-8] (16). Retro-vitamin A [16729-22-9] (17) is obtained by treatment of retinol in the presence of concentrated hydrobromic acid. In the case of retinoic acid and retinal, reisomerization is possible after conversion to appropriate derivatives such as the acid chloride or the hydroquinone adduct. Table 1 Hsts the physical properties of -carotene [7235-40-7] and vitamin A. 

Adsorption of Radionuclides. Other appHcations that depend on physical adsorption include the control of krypton and xenon radionuchdes from nuclear power plants (92). The gases are not captured entirely, but their passage is delayed long enough to allow radioactive decay of the short-hved species. Highly rnicroporous coconut-based activated carbon is used for this service. 

Einfall, m. falling in, fall, decay, inroad, idea (Physics) incidence. 

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