Nitrate history

The development of theoretical organic chemistry was intimately entwined with the development of that particular aspect of it concerned with aromatic substitution the history of this twin growth has been authoritatively traced. Only the main developments, particularly as they affect nitration, will be noted here. 

To establish the required causal effect of production rate on nitrates a year s history was investigated. For various production rate ranges the percentage of nitrate contents of various magnitudes was tabulated as follows ... 

Tliere is another type of application where the damping effect of plastic structures can be used to advantage. It has a long although not obvious history. The early airplanes used doped fabric as the covering for wings and other aerodynamic surfaces. The dope was cellulose nitrate and later cellulose acetate that is a damping type of plastic. Conse-... 

Indeed it can be stated that the history of modern expls begins with the discoveries of nitroglycerin (NG) and nitrocellulose (or more correctly cellulose nitrate or NC) nearly 125 years ago, and their application to military and commercial usage. An excellent review of the early history of NC is given by. T.L. Davis (Ref 29, pp 244—56). The early histories of NG and EGDN (discovered in 1870) are summarized, respectively, in Vol 6, G99-R to G100-R and E259-R, and in the Naoum reference cited above... 

Atmospheric aerosols have a direct impact on earth s radiation balance, fog formation and cloud physics, and visibility degradation as well as human health effect[l]. Both natural and anthropogenic sources contribute to the formation of ambient aerosol, which are composed mostly of sulfates, nitrates and ammoniums in either pure or mixed forms[2]. These inorganic salt aerosols are hygroscopic by nature and exhibit the properties of deliquescence and efflorescence in humid air. That is, relative humidity(RH) history and chemical composition determine whether atmospheric aerosols are liquid or solid. Aerosol physical state affects climate and environmental phenomena such as radiative transfer, visibility, and heterogeneous chemistry. Here we present a mathematical model that considers the relative humidity history and chemical composition dependence of deliquescence and efflorescence for describing the dynamic and transport behavior of ambient aerosols[3]. 

Influence of the mode of operation on process performance. The mode of operation of stirred-tank reactors can also significantly affect reactor performance. The history of concentrations will be changed by the time policy of reactant(s) addition to the reaction mixture. In view of our very limited possibility of controlling of temperature in stirred-tank reactors, the temperature-time dependencies for different policies of dosing will also be different. For example, the result of nitration depends upon the method of addition of nitric acid to aromatics, and the choice which phase is dispersed and which is continuous. Consequently, if the reaction is concentration- or temperature-sensitive the result will be dependent on the mode of operation (see Example 5.3.1.5). 

Before nitrates and particularly ammonium nitrate were readily available commercially, explosives were developed based on chlorates and perchlorates. These also are still used in some countries. In general perchlorates are considered less dangerous than chlorates and therefore preferred. They are easily sensitised, so that in addition to explosives of this type based on nitroglycerine, others have been based on various organic liquids, particularly nitrobodies. History shows that chlorates and perchlorates must be regarded as temperamental substances, liable in bulk to lead to inexplicable accidents. Particularly when mixtures of chlorates and oxidising materials are allowed to become wet and then dry out, conditions can arise in which there is an appreciable sensitiveness to friction and impact. Explosives of this type have an unfortunate record of accidents. They are used, therefore, to a limited extent only, now that safer compositions are available. 

Silver and mercury salts have a long history of use as antibacterial agents.241-243 The use of mercurochrome ((40), Figure 18) as a topical disinfectant is now discouraged. Silver sulfadiazene (38) finds use for treatment of severe burns the polymeric material slowly releases the antibacterial Ag+ ion. Silver nitrate is still used in many countries to prevent ophthalmic disease in newborn children.244 The mechanism of action of Ag and Hg is through slow release of the active metal ion—inhibition of thiol function in bacterial cell walls gives a rationale for the specificity of bacteriocidal action. 

As mentioned earlier, there are many nitrogen compounds that are either explosives or propellants. That is one reason why nitrates and nitric acid have been so important throughout several centuries of history. 

Over a century ago, empirical observation was made that organic nitrates, including glyceryl trinitrate (GTN), alleviate angina. Since then, GTN has been a mainstay therapy for angina and cardiac failure, even with the possible loss of effectiveness (tolerance) over extended dosing [55] and the risk of platelet hyperactivity in GTN-tolerant patients [54]. Despite this venerable therapeutic history, the mechanism of GTN bioactivation to NO is speculative at best [38]. In 1967, some 15 years before identification of NO as a biological entity, GTN was the first nitrovasodilator shown... 

The most important nitrolysis reaction to date is the formation of RDX (3) and HMX (4) from the caged methylenediamine known as hexamine (104). These important military explosives were first mass manufactured by this route towards the end of the Second World War and they are still prepared by this route today. The process uses a mixture of acetic anhydride, ammonium nitrate and nitric acid. The nitrolysis of hexamine is one of the most widely studied reactions in the history of explosives. Many other cyclic and linear polynitramines have been isolated from these reactions and this rich chemistry is discussed in more detail in Section 5.15. 

Black powder is the oldest explosive in history, dating back to the eighth century. Its chemical composition is well-known as a mixture of potassium nitrate, sulfur, and charcoal. The mixture ratio is varied according to the purpose for which it is to be used, with the ranges kno3(0-58-0.79), (0.08-0.20), and ( (0.10-0.20). Black powder composed of particles less than 0.1 mm in diameter is used for shell burst of fireworks and fuses. The grade with diameter 0.4—1.2 mm is used for the launch of spherical shells of fireworks, while that with diameter 3-7 mm is used in stone mines. Since black powder is sensitive to sparks caused by mechanical impact, friction, and static electricity, black powder containers should be made of brass or aluminum alloys rather than iron or steel. When Cl and Ca or Mg are present as impurities, CaClj or MgClj is formed and the thermal performance of KN is reduced. Contamination with NaCl also needs to be avoided for the same reason. 

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