Fire, chemistry solids

As broad as the coverage of this symposium appears, there is much propellant chemistry which has not been included. The experimental determination of thermodynamic properties such as heats of formation and equilibrium constants as well as the calculations of theoretical performance have been presented at other symposia. The applied chemistry related to modifying polymers, and hence mechanical and burning properties of solids, have other forums. The actual firing of solid motors and determination of thrust and efficiency have been omitted while the research into combustion instability and the transition from deflagration to detonation are only alluded to. 

This symposium addressed several important issues in bromine chemistry. A major part has been devoted to stereochemistry and mechanism of electrophilic bromination of olefins. Other topics included new selective methods of bromination and oxybromination, brominations in presence of solid supports and catalysts, organobromine compounds as synthons, recent developments in brominated fire retardants and toxicological and environmental aspects of brominated compounds. 

The importance of chemistry to the nuclear power industry is now well recognized. Chemical control in water circuits is an accepted part of the operating requirements of nuclear generating stations, as it is for modern fossil-fired stations. While there have been major advances in knowledge of the chemistry of aqueous systems at temperatures above lOQoC, there is still a need for further work. As we improve our understanding of thermodynamics and kinetics of solid-aqueous reactions and the effect of radiation on them, we can expect further advances in controlling radiation fields in reactor circuits and in minimizing iron deposition in GS plants. 

THE USE OF FIRE TO transform CLAY PASTE into solid ceramic vessels may have been one of the earliest efforts at chemistry. Since the earliest times, pottery has been made by using clays formed by the weathering of rocks. Sedimentary deposits containing clay minerals also contain fragments of other minerals that are broken from the source rocks as they weather. The chemical composition of the sediments used as a clay source determined some of the characteristics of the pottery that was produced. 

Potassium sulfide, K2S, is a binary salt. It is a red or yeUow-red crystalline mass or fused solid. It is deliquescent in air, which means it absorbs water from the air, and it is also soluble in water. Potassium sulfide is a dangerous fire risk and may ignite spontaneously. It is explosive in the form of dust and powder. It decomposes at 1562°F and melts at 1674°F. The specific gravity is 1.74, which is heavier than air. The four-digit UN identification number is 1382. The NFPA 704 designation is health 3, flammability 1, and reactivity 0. Potassium sulfide is used primarily in analytical chemistry and medicine. 

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