Explosion , Impulse in

Impulse (or momentum), in the physical sense, may be defined as the product of force and the time during which it acts 

Dunkle (Ref 8) defines it as mass times velocity equals force times time and gives the following equation  

The term is sometimes loosely used to mean impact and shock as, for instance, in Ref 3, pp 161-62 (Thermal effects 

The so-called positive impulse in a shock wave is the area under the pressuretime curve Phases of a Shock Wave represented as shaded area in Fig 15, p 51 

Bron et al, New Method for Recording Explosion Impulse Effects on Solids , ASTM Bulletin, Feb 1957, 50(TP38) 

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Detonation (and Explosion), Impulse Specific in Jet Propulsion (lsp). See under Detonation (and Explosion), Impulse in... 

Explosion, Impulse in. See Vol 4, p D393-L R. Included is definition of Isp-specific impulse employed in jet propulsion... 

Though the oxidation potentials of potassium nitrate (KN KNO3) and sodium nitrate (SN NaN03) are high, both metal nitrates generate combustion products of high Mg, Thus, the specific impulse becomes low when KN or SN is used in a rocket propellant KN and SN are used as major ingredients of explosives and in pyrotechnics. KN is a weU-known material as a major component of black powder. 

Behavior of Explosives at Impulsively In-duced High Rates of Strain" was discussed by H.S. Napadensky et al at the 3rdONRSymp-Deton, Vol 2, pp 420-35(1960)... 

Detonation, Specific Impulse in. See Detonation (and Explosion) Impulse, Specific in... 

To gain some insight into these phenomena, without getting too involved in mathematical complexities, let us first examine some limiting cases of impulse delivered to a) a rigid wall b) air (for HE detonations there is very little difference in the final results in the explosive impulse delivered to air or to a vacuum)... 

Effects of Boundary Rarefaction on Impulse Delivered by Explosive Charges During Detonation (or Explosion). Described in the paper of Taylor listed in Vol 4, p D257-R... 

In these explosives, and in the ammonium nitrate permissible explosives which contain still less nitroglycerin, it is supposed that the nitroglycerin or the nitroglycerin jelly, which coats the particles of ammonium nitrate, carries the explosive impulse originating in the detonator, that this causes the ammonium nitrate to decompose explosively to produce nitrogen and water... 

In an explosive train, that component which, when detonated by the primer, in turn detonates a less sensitive but larger high explosive (usually the booster) or when containing its own primer initiates the detonation. The detonator can be activated by either an explosive impulse (primer) or a non-explosive impulse. When activated by a nonexplosive impulse, the detonator contains its own primer. Detonators are generally classified as percussion, stab, electric, or flash, according to the method of initiation. Explosive charge placed in certain equipment and set to destroy the equipment under certain conditions (-> Initiator). 

Haloperidol is a butyrophenone derivative with antipsychotic action similar to that of piperazine phenothiazines such as fluphenazine. Haloperidol (0.5 to 2 mg t.i.d.) is indicated in the management of psychotic disorders in Tourette s disorder for the control of tics and vocal utterances in severe behavioral problems of children with combative and explosive nature in hyperactive impulse disorder in children associated with aggression, low fmstration tolerance, and impulsive behavior, and in elderly subjects with senile dementia (see also Table 9). 

Storage Media Failure. Electronic records in a storage facility exist in the form of physical media that can be compromised. Fire, explosion, contamination, electronic impulses (in some cases), flooding (in some cases), or simple longterm signal degradation (more a problem in some cases than others) can render content unrecoverable. 

Like the explosion on the ground, explosion in water increases the pressure of water shock waves. For rigid water bottom, it equals two times of explosion power. In fact, the water bottom is not absolutely rigid, and it absorbs part of energy. Experiments indicate that in the water bottom with sandy soils, shock wave pressure increases up 16 % and impulse goes up 35 %. 

In general, full 3-D finite element analysis of the fluid domain (impulse, in the case of wind or explosions) or full impact analysis (impact, in the case of aircraft crash or tornado missiles) are not used in the design process for the derivation of a suitable load function. Very detailed research programmes have been carried out in the engineering community and in some cases simplified engineering approaches are now available for a reliable design process, on the basis of the interpretation of test data or data from numerical analysis. 

Characteristic Sachs dimension Re = [P/Pol was taken as a reference scale to neglect the shape of the explosive volume in determining the relative distance R =R/Re. That approach does not imply analysis of blast wave parameters at distances of 1 < P/Py < 3. In experiments described in [1], the radius of the cylinder filled with HAM was Py = 1.7 m. In mixtures with less than 28.7% H2 content the pressure and impulse values became lower. 

Pressure and impulse in the pressure wave determine the danger level resulting from an explosion of hydrogenous combustible mixtures. The main measurable blast wave parameters are presented in the diagram (Fig. 10.1). The blast wave pressure in a gas explosion is a function of the energy release rate and it reaches a maximum at the detonation mode of combustion [1 ]. 

A notable characteristic of the plane explosion in a duct is the lack of a negative pressure phase, if there is no water steam condensation, the same as it is for a H2 + O2 mixture explosion. The blast wave pressure impulse in a duct is practically constant throughout the length R/Rq 100 provided that there is no loss due to friction. In combination with moderate attenuation of the front there is evidence of compression phase expansion as the wave is moves though the duct. 

Propellants and Explosives. Hydrazine fuels include anhydrous hydrazine (AH), monomethyUiydrazine (MMH), and unsymmetrical dimethyUiydrazine (UDMH) for military and space programs. These compounds are used mainly as bipropeUant fuels, ie, with oxidizers, in rockets such as the Titan, MX missile, and the Ariane (UDA4H7X30. Using oxygen or fluorine as the oxidizer, hydrazine is exceeded only by hydrogen in specific impulse, ie, kilograms of thmst developed for each kilogram of fuel consumed per second (196). 

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