scholarly journals Rate of Escape of the Mixer Chain

2009 ◽  
Vol 14 (0) ◽  
pp. 347-357
Author(s):  
Ariel Yadin
Keyword(s):  
1941 ◽  
Vol 25 (2) ◽  
pp. 247-261
Author(s):  
Eric Ponder

The acceleration of saponin hemolysis by benzene, indol, and nonyl alcohol has been investigated as a function of temperature, and it has been found that these accelerators have negative temperature coefficients. This points to their being concentrated at the cell surface, and to the surface being the seat of their accelerating action. It is shown that the accelerating power of indol (used as a typical accelerator) is constant so long as the lysin in the system is capable of producing lysis per se, but that the acceleration falls off when only sublytic concentrations are present. The relations are expressed in a series of equations, and explained in terms of the reactions among the accelerator, the lysin, and the membrane component, which breaks down in spots, rather than uniformly, when lysis occurs. The argument involves a consideration of the idea that a monolayer of lysin at the cell surface is necessary for hemolysis, of Abramson's hypothesis of "key spots" on the surface, of the rate of escape of hemoglobin from the hemolyzing cell, and of the results of electrophoretic and impedance measurements. The existing theory of the kinetics is extended by introducing the idea of a variation in resistance from point to point in the cell membrane; in this form it describes the situation so far as is at present known, and shows that the results of the various methods of investigation are consistent with each other. The only idea discussed which seems to have little foundation is that lysis is determined by the formation of a monolayer of lysin at the cell surface; when this occurs, it must do so only as a special case. Finally, a semi-quantitative description of the frequency distribution of the resistances in the membrane is derived from existing data. The variation in resistance which it is necessary to assume is quite small, as might be expected in the case of a membrane with a regular ultra-structure.


2016 ◽  
Vol 01 (02) ◽  
pp. 1650010 ◽  
Author(s):  
Vladimir I. Dubinko ◽  
Alexander S. Mazmanishvili ◽  
Denis V. Laptev ◽  
Juan F. R. Archilla

At sufficiently low temperatures, the reaction rates in solids are controlled by quantum rather than by thermal fluctuations. We solve the Schrödinger equation for a Gaussian wave packet in a non-stationary harmonic oscillator and derive simple analytical expressions for the increase of its mean energy with time induced by the time-periodic modulation. Applying these expressions to the modified Kramers theory, we demonstrate a strong increase of the rate of escape out of a potential well under the time-periodic driving, when the driving frequency of the well position equals its eigenfrequency, or when the driving frequency of the well width exceeds its eigenfrequency by a factor of [Formula: see text]. Such regimes can be realized near localized anharmonic vibrations (LAVs), in which the amplitude of atomic oscillations greatly exceeds that of harmonic oscillations (phonons) that determine the system temperature. LAVs can be excited either thermally or by external triggering, which can result in strong catalytic effects due to amplification of the Kramers rate.


2008 ◽  
Vol 45 (03) ◽  
pp. 689-702
Author(s):  
Francis Comets ◽  
François Simenhaus

We study a continuous-time random walk on thed-dimensional lattice, subject to a drift and an attraction to large clusters of a subcritical Bernoulli site percolation. We find two distinct regimes: a ballistic one, and a subballistic one taking place when the attraction is strong enough. We identify the speed in the former case, and the algebraic rate of escape in the latter case. Finally, we discuss the diffusive behavior in the case of zero drift and weak attraction.


1956 ◽  
Vol 93 (5) ◽  
pp. 353-368 ◽  
Author(s):  
G. H. Francis

AbstractAn examination of existing definitions of facies and subfacies boundaries in pelitic rocks suggests that some alteration is necessary to emphasize two important reactions:3 Staurolite + 2 Quartz ⇌ Almandine + 5 Al2SiO5 + 3 Water, andMuscovite + Quartz ⇌ Potash feldspar + Al2SiO5 + Water A generalized plot shows possible relations between the curves of these two reactions and the inversion, curves of the aluminosilicates within the P-T field of metamorphism. The curves of further reactions commonly used to define facies and subfacies boundaries have been schematically added to this plot, and trends of metamorphism in various areas are indicated thereon. P-T curves of dehydration reactions such as the above will vary according to the chemical potential of the water vapour in each particular case. Observations suggest, however, that the curves are not very differently placed from one regional metamorphic terrain to another. That is, the rate of escape of volatiles is broadly similar in the metamorphism of many of these terrains.


1989 ◽  
Vol 40 (10) ◽  
pp. 7295-7297 ◽  
Author(s):  
Ulrike Griff ◽  
Hermann Grabert ◽  
Peter Hänggi ◽  
Peter S. Riseborough

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