Intensity effect from shock heated

Historically, thermal and mechanical mechanisms for the initiation of fast reactions have been closely linked because, while it is common experience that explosions can be thermally initiated, it is also common to assume that the energy of any mechanical stimulus applied to an azide is first converted to heat before an explosion results (Chapter 8). Alternative mechanisms whereby the mechanical energy is absorbed as strain energy or in the fracture of crystals have not been given extensive consideration, although such possibilities have been proposed by Taylor and Weale [45], Ubbelohde [46,47], and others from the 1930s onward. The question of whether localized plastic flow or adiabatic shear can lead to the initiation of explosives under the action of low-intensity shocks has recently been given renewed attention [48]. Such considerations draw further attention to the lack of data on the mechanical properties of azides and explosives upon which to base quantitative assessments. Mechanical stimuli can also produce electric effects, and some of the possible consequences are discussed in the next section. 

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