Premature firing

Premature Firing of Rounds, or Premature Ignition of Propellants (In collaboration with N.D. Baron of ADED Picatinny Arsenal)... 

Uses Replacement for TATB, main component of thermally stable explosives, addictive with initiating compositions to protect against premature firing of blasting caps or detonators as a result of EMF s, and EMP bursts, and component in rocket propellants with HMX or RDX to increase thrust. ... 

Premature shutdown of fans/venti-lation system immediately following shutdown of heat input (prior to sufficient cooling) resulting in hot spots and flammable pockets (dryers, carbon beds, and thermal oxidizers). Possibility of subsequent ignition resulting in fire or explosion. 

Excessive temperature can lead to premature failure of an item of equipment at pressures below its design maximum working pressure. Such a failure can create a leak, potentially leading to fire or explosion if gas is leaked or to oil pollution if oil is leaked. This type of failure should be gradual, with warning as it develops, and thus does not require as higli a degree of protection as those previously mentioned. 

Wear of medical devices and biomaterials can affect quality of life. Wear of tooth fillings, artificial joints and heart valves can be inconvenient, costly (more frequent replacement) or even life-threateiiiiig (premature breakdowns). Wear of components can also cause accidents. Worn brakes and tires can cause automobile accidents, worn electrical cords can result in electrocution and fires and worn out seals can lead to radiation leaks at nuclear power plants. 

Figure 10.13. Vanadia wall deposits in a power plant firing Orimulsion fuel catalyze the premature oxidation of SO2 in heat exchangers. Note that potassium enhances the undesired conversion while a selective poison diminishes the effect to some extent.

This study demonstrate similar ranking of each material independent of test method used. At this stage it is premature to choose one test as a better small scale model of full scale fires. Each method needs further elaboration. 

However, the relatively low reported Ea of 8.14 kcal/mol (43) suggests that even moderately warm temperatures over several years, such as roof structures experience during the summer months, may be sufficient to form phosphoric acid. Ammonium sulfate, which can also thermally disassociate to form an acid (7,40), may cause even more degradation to lumber than ammonium phosphates (40,44). This thermal disassociation of ammonium salts may be the cause of the premature degradation recently observed in some fire retardant treated plywood roofing material. 

A car engine typically requires four cylinders, which fire in a carefully synchronized manner. Unfortunately, these explosions sometimes occur prematurely, before... 

The GPCR process was able to achieve 5X decontamination of carbon, PCP-spiked wood, DPE suit material, firing tubes, and HD mortar casings. However, the first run with DPE suit material was stopped prematurely because the reactor input line plugged. 

Fuzes contain safety devices that tend to prevent functioning until after the fuze has been subjected to centrifugal and setback forces, after the round is fired. In the so-called bore-safe fuzes, the path of the explosive train is interrupted so that, while the projectile is still in the bore of the weapon, premature expln is prevented should any of the more sensitive fuze elements (such as primer and/or detonator) start to function. Interruption is usually achieved by inserting out-of-line components or interrupter blocks or slides. Although this leaves the fuze in an unarmed position, it would not be considered safe in handling or shipping, unless the fuze was not provided with safety devices such as safety wires or cotter pins. These outside devices must be removed prior to inserting the fuzed round of ammunition into gun barrel, but the fuze will still be unarmed because some of its inside parts are not free to move to their proper positions so that the fuze may operate in its intended manner... 

Some American shells loaded with 50/50 Pentolite prematured and it was believed that the cause was exudation thru the closure at die base of the shell and that the exudate set up an explosive train which was subsequently ignited by the propellant when the gun was fired. When similar shells were later tested, it was shown that heating above... 

An AA projectile gave a bore premature which burst a gun killing most of the crew. About 6000 similar projectiles were carefully examined for defects but nothing suspicious could be found. About ten years later it was found that the base of some of these projectiles contained tiny perforations and it is possible that hoe propellant gases penetrated inside the shell when it was fired. 

When shells with artificially perforated bases were fired experimentally, prematures were obtained... 

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