Nitroglycerine, initiation

Safety has been greatly increased by use of the continuous nitration processes. The quantity of nitroglycerin in process at any one time is greatly reduced, and emulsification of nitroglycerin with water decreases the likelihood of detonation. Process sensors (qv) and automatic controls minimize the likelihood of mnaway reactions. Detonation traps may be used to decrease the likelihood of propagation of an accidental initiation eg, a tank of water into which the nitrated product flows and settles on the bottom. 

Continuous infusions of nitroglycerin should be initiated at a dose of 5 to 10 mcg/minute and increased every 5 to 10 minutes until symptomatic or hemodynamic improvement. Effective doses range from 35 to 200 mcg/minute. The most common adverse events reported are headache, dose-related hypotension, and tachycardia. A limitation to nitroglycerin s use is the development of tachyphylaxis, or tolerance to its effects,... 

Oral Nitroglycerin extended- 2.5 mg 3 times daily initially, with... 

Nitroglycerine and other high explosives of this type are difficult to initiate into detonation simply by the use of a flame. Mercury fulminate, discovered by Howard, is an explosive of relatively low power which can, however, always be relied on to detonate when ignited by a flame. Explosives like mercury fulminate are known as initiating explosives. 

By adiabatic compression of gas. This is particularly noticeable in liquid explosives such as nitroglycerine, where eveq the moderate compression of small gas bubbles can readily lead to initiation of the explosive. 

Paste. In double base propellant manufacture, the initial mixture of guncotton and nitroglycerine. 

Nitroglycerin should be initiated at 5 to 10 mcg/min (0.1 mcg/kg/min) and increased every 5 to 10 minutes as necessary and tolerated. Maintenance doses usually range from 35 to 200 mcg/min (0.5 to 3 mcg/kg/min). Hypotension and an excessive decrease in PAOP are important dose-limiting side effects. Some tolerance develops in most patients over 12 to 72 hours of continuous administration. 

Secondary explosives (also known as high explosives) are different from primary explosives in that they cannot be detonated readily by heat or shock and are generally more powerful. Secondary explosives can be initiated to detonation only by a shock produced by the explosion of a primary explosive. Widely used secondary explosives include trinitrotoluene (TNT), tetryl, picric acid, nitrocellulose, nitroglycerine, nitroguanidine, cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranit-... 

When ethyl nitrate is rapidly heated, for example in a flame, it decomposes explosively it belongs to the same class of substances as nitroglycerine. Precautions should therefore be taken. Under the conditions employed ethyl alcohol is not oxidised by pure nitric acid but merely esterified. Oxidation sets in immediately if traces of nitrous acid are present. Since the nitric oxide which is thus produced from the nitrous acid is at once oxidised to NOz by the nitric acid, the oxidation, which is initially slight, becomes progressively greater, its velocity... 

Thus, nitroglycerin s explosive properties are caused by three factors the energy that is given off by its decomposition, the rate at which the reaction occurs, and the small amount of energy that is needed to initiate the reaction. In this unit, you will learn about the energy and rates of various chemical reactions. 

Nitroglycerin will be effective for on-going chest pain relief. Ca channel antagonists and long-acting Nitrates can be used when jS-blockers are contraindicated. These drugs may be also used for the initial therapy, additional to -blockers or when jS-blockers treatment failed. However, for the effectiveness of vasodilatation itself is relatively weaker evidence. 

Heat of nitration of glycerin. Suppose we wish to estimate the heat evolved in nitrating 1 mole of glycerin with mixed acid. To simplify this illustrative example we will assume initial mixture — 1 mole glycerin/3 moles 100% nitric acid/6 moles 100% sulfuric acid final mixture -1 mole nitroglycerin completely separated from the spent acid which is now diluted by 3 moles of water the entire heat of dilution is due to 3 moles water dissolving in 6 moles of 100% sulfuric acid. Thus... 

More in line with the predictive use of hazards analysis, however, is the experimental and theoretical assessment that the viscosity of the liquid significantly affects this mode of initiation. Such information allows redesign of the process to eliminate handling of low viscosity liquid explosives, and quantitative measurement of the sensitivity of the system to mild shocks as a function of viscosity may allow the optimum level to be selected. This is not necessarily a new concept, only quantified in a different manner. Thirty years ago transporters of neat nitroglycerine in the oil fields were paid 25 a day. The stipend for transporting jellied nitroglycerine was seven dollars, a practical comment on the understood difference in hazard. 

The initial dissolution is now usually carried out in copper tubs with a water jacket which maintains a temperature of 45-50°C in the tub. The tubs contain 100 kg of a mixture of nitroglycerine and nitrocellulose. Their contents are stirred with wooden paddles and then allowed to stand for 20-30 min. This is sufficient time for complete dissolution of nitrocellulose at this temperature. 

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