Self-acceleration influence

Reactivity (instability) information Acceleration rate calorimetry Differential thermal analysis (DTA) Impact test Thermal stability Lead block test Explosion propagation with detonation Drop weight test Thermal decomposition test Influence test Self-acceleration temperature Card gap test (under confinement) JANAE Critical diameter Pyrophoricity... 

Since the early days of using PVC separators in stationary batteries, there has been a discussion about the generation of harmful substances caused by elevated temperatures or other catalytic influences, a release of chloride ions could occur which, oxidized to perchlorate ions, form soluble lead salts resulting in enhanced positive grid corrosion. Since this effect proceeds by self-acceleration, the surrounding conditions such as temperature and the proneness of alloys to corrosion as well as the quality of the PVC have to be taken carefully into account. 

The constant K in this equation, as in some other cases discussed above, denotes the initial reaction rate. Its temperature dependence is described by the standard Arrhenius equation with activation energy U. The constant co characterizing the self-acceleration does not depend on temperature but does depend on the composition of the reactive medium in particular, such factors as the chemical structure and concentration of the curing agent, and the concentration of the catalyst and other components influence the value of co. 

An identical mathematical description of the kinetics of curing of reactants different in chemical nature and that obtained on the basis of fundamentally different experimental methods allows us to assume that this apparent selfacceleration course of some rheokinetic parameters is common to the processes of formation of materials with a crosslinked structure. It should be emphasized once more that the self-acceleration" effect must not be identified with the self-catalysis of the reaction of interaction between epoxy monomers and diamines which is studied in detail on model compounds [116, 117]. For each particular curing process the self-acceleration effect is influenced by the mechanism of network formatic, namely, chemical self catalysis [118], the appearance of local inhomogeneities [120], the manifestation of gel eff t [78], parallel course of catalytic and noncatalytic reactions [68]. It is probably true that the phenomena listed above may in one form or another show up in specific processes and make their contribution into self-acceleration of a curing reaction. 

The interplay of those influences which inhibit adhesion and those which promote it must be recognized in interpreting two commonly encountered aspects of rubbing contact smooth, regular, controlled wear on the one hand, and destructive, self-accelerating catastrophe on the other. Figure 12-25 shows the appearance of two locations on a disk of hardened steel used in a pin-and-disk wear experiment at a contact pressure of 1069 MPa (10,900 kg/cm ) and a rubbing speed of 0.508 m/s with... 

In the branching chain reactions the effect of the inhibitor in the framework of analytical approach usually is estimated by its influence on the parameter of self-acceleration factor [16], which defines the propagation rate of a chain process (see Chapter 1). 

One of the features of this sort of cyclic coupling of causes and effects is that self-accelerating as well as self-saturating processes result. In the normal case the feedback between individuals and the collective field leads to a sustained quasi-stable or evolutionary phase, i.e. a self-consistent collective structure of society. In this case there exists a certain predictability of further development because the space of mutually influencing relevant macrovariables (taken from the socio-political and economic situation) is known and these macrovariables obey a quasi-closed subdynamics. 

The carbon purity is one of the key properties, which must be maintained during all the production process as it will influence the potential window in which the DLC is stable during its use. The presence of impurities and possible oxidation-reduction reactions result in a pressure build up in the DLC cell. Excessive pressure may lead to the opening of the cell with the consequence of electrolyte leakage. The presence of impurities will also accelerate the self-discharge and the aging of the component. A corresponding capacitance decrease and a series resistance increase are also observed. 

The stepwise migration of ions under the influence of an electric field is an important feature of capillary isotachophoresis. Should an ion diffuse out of its zone, it will experience the electric field, which is driving the zone into which it has diffused. This will cause it to either accelerate or decelerate back into its own zone, depending on the magnitude of the electric field. This effect produces a self-sharpened zone, which serves to maintain sharp zone boundaries. 

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