Propagation of chemical change

The propagation of flame and explosion is one of the most spectacular manifestations of chemical change. It differs from the examples hitherto considered in that the temperature of the system is not uniform. 

Weigert and Kellermann obtained direct evidence of the propagation of chains in mixtures of hydrogen and chlorine. By photographic methods they were able to show that when the mixture was illuminated momentarily the chemical change, as rendered visible by the changes in refractive index caused by the heat of reaction, did not... 

At this point we have described nuclear transitions and reactions that produce various forms of nuclear rad iation. The radiation propagates out from the originating nucleus and interacts with other matter along its path. These interactions with external matter allow us to observe the radiation, and its effects, and to determine the nature of the transition inside the nucleus. The interaction of radiation with matter is also the cause of chemical, physical, and biological changes that concern the public at large. We will specifically address the operating principles of radiation detectors in the next chapter, but first we will consider the fundamental interactions of nuclear radiation with matter. 

The ratio (10) that we obtain is so small that there is no need to attempt to establish more exactly the relation between the heat transfer and heat of reaction in the various theories of normal combustion [3, 4, 15-18], or the accuracy of the temperature differences in the detonation wave, or to undertake other similar operations which can in no way change the basic results the smallness of the heat flux in the direction of propagation of detonation the adiabatic character (which holds with great accuracy as long as we do not consider heat losses to the walls of the tube) of the chemical reaction in the detonation wave the impossibility of any noticeable role of heat transfer from the heated combustion products in ignition of the fresh, unreacted gas. 

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