Pressure explosives

High pressure explosive loading was carried out on both z- and y-cut crystals at pressures between about 25 and 60 GPa ([83S01, 77S01]). The z-cut crystals responded in the plus-x orientation with current pulse wave shapes as predicted by the three-zone model. Nevertheless, limited experiments in the minus-z orientation of lithium niobate do not show the positive currents expected from the three-zone model. 

B02 E.K. Beauchamp and M.J. Carr, in High Pressure Explosive Processing of Ceramics, edited by R.A. Graham and A.B. Sawaoka (Transtech, 1987), pp. 175-206. 

Nuclear installations are provided with a pressure explosion suppression and containment shell as an accommodation system against any sudden energy release resulting from an uncontrolled nuclear fission reaction. The internal air pressure is maintained at a level lower than the external atmosphere. 

Dining evaporation of an alkaline aqueous solution of the nitrate, decomposition led to gas evolution and a pressure explosion occurred. This was attributed to the use of recovered alkali containing high levels of lead and iron, which were found to catalyse the thermal decomposition of the nitrate. Precautions to prevent recurrence are detailed. 

A year-old bottled sample, containing syrupy phosphoric acid as stabiliser and which already showed signs of tar formation, exploded in storage. The pressure explosion appeared to be due to polymerisation, after occlusion of inhibitor in the tar, in a container in which the stopper had become cemented by polymer [1], A similar pressure explosion occurred when dry redistilled nitrile, stabilised with ethanol [2], polymerised after 13 days [3], The spontaneous and violent decomposition of the nitrile on standing for more than a week is usually preceded by formation of a red polymer [4],... 

Two violent pressure-explosions occurred during preparations of dimethylsulfinyl anion on 3-4 g mol scale by reaction of sodium hydride with excess solvent. In each case, the explosion occurred soon after separation of a solid. The first reaction involved addition of 4.5 g mol of hydride to 18.4 g mol of sulfoxide, heated to 70°C [1], and the second 3.27 and 19.5 g mol respectively, heated to 50°C [2], A smaller scale reaction at the original lower hydride concentration [3], did not... 

Decomposition and a pressure explosion occurred while a 10 kl tanker with steamheating coils was being unloaded. 

I7Ian Swift and Mike Epstein, Performance of Low Pressure Explosion Vents, Plant/Operations Progress (April 1987), 6(2). 

Explosions or ruptures of vessels or process equipment from internal deflagrations, runaway reactions or pressure explosions with possible damaging shock wave and missile ejection. 

Figure 10-8 Explosion limits of the H2 + O2 reaction, At low pressures explosion is determined by the quenching of chain branching of radicals at the walls of the vessel, while at high pressures the larger rate of heat generation leads to a thermal explosion,...

Highways and Byways in Combustion. Title of a paper by D.T.A. Townsend, JlnstFuel 27, 534-44 (1954) CA 49, 2057 (1955). In this paper investigations of high-pressure explosions, flame propagation and combustion of higher-mol-wt hydrocarbons are reviewed... 

Low Detonation Pressure Explosives. Most expl materials in wide use today may be characterized by deton pressures ranging from approx 150—350 kilobars. Propint materials, on the other hand, exhibit comparatively low press typical of deflgrn reactions. The difference in pressures exhibited by these two classes of materials leaves an interesting gap, the exploration of which may yield valuable information on the propagation and kinetic limitations of detong materials... 

The Dow Chemical Company High Pressure Explosive Compositions and Method Using Hollow Glass Spheres... 

Two violent pressure-explosions occurred during preparations of dimethylsulfinyl anion on 3—4 g mol scale by reaction of sodium hydride with excess solvent. In each case, the explosion occurred soon after separation of a solid. The first reaction involved addition of 4.5 g mol of hydride to 18.4 g mol of sulfoxide, heated to 70°C [1], and the second 3.27 and 19.5 g mol respectively, heated to 50°C [2]. A smaller scale reaction at the original lower hydride concentration [3], did not explode, but methylation was incomplete. Explosions and fire occurred when the reaction mixture was overheated (above 70°C) [4]. Reaction of 1 g mol of hydride with 0.5 1 of sulfoxide at 80°C led to an exotherm to 90°C with explosive decomposition [5]. These and similar incidents are explicable in terms of exothermic polymerisation of formaldehyde produced from sulfoxide by reaction with the hydride base [6]. The heat of reaction was calculated and determined experimentally. Thermal decomposition of the solution of hydride is not very violent, but begins at low temperatures, with gas evolution [7]. 

DMNB was determined not to be an odorant by the majority of the canine population tested. On three separate field trials, there was not one alert to the DMNB source involving different canine teams and different amounts of DMNB ranging from 100 xg to 5 mg. Although this was not observed to be an odorant, it is recommended that DMNB be included in a training aid selection because of its sole application in the tagging of low-vapor-pressure explosives. 

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