The explosive power of nitroglycerin derives from detonation: energy from the initial decomposition causes a strong pressure wave that detonates the surrounding fuel. This is a self-sustained shock wave that propagates through the explosive medium at 30 times the speed of sound as a near-instantaneous pressure-induced decomposition of the fuel into a white-hot gas. Detonation of nitroglycerin generates gases that would occupy more than 1,200 times the original volume at ordinary room temperature and pressure. The heat liberated raises the temperature to about 5,000 °C (9,000 °F). This is entirely different from deflagration, which depends solely upon available fuel regardless of pressure or shock. The decomposition results in a much higher ratio of energy to gas moles released compared to other explosives, making it one of the hottest detonating high explosives. Manufacturing
Nitroglycerin can be produced by acid-catalyzed nitration of glycerol (glycerin). The industrial manufacturing process often reacts glycerol with a nearly 1:1 mixture of concentrated sulfuric acid and concentrated nitric acid. This can be produced by mixing white fuming nitric acid—a quite expensive pure nitric acid in which the oxides of nitrogen have been removed, as opposed to red fuming nitric acid, which contains nitrogen oxides—and concentrated sulfuric acid. More often, this mixture is attained by the cheaper method of mixing fuming sulfuric acid, also known as oleum—sulfuric acid containing excess sulfur trioxide—and azeotropic nitric acid (consisting of about 70% nitric acid, with the rest being water). The sulfuric acid produces protonated nitric acid species, which are attacked by glycerols nucleophilic oxygen atoms.
Combined immunodeficiencies (or combined immunity deficiency) are immunodeficiency disorders that involve multiple components of the immune system, including both humoral immunity and cell-mediated immunity. This category includes conditions such as bare lymphocyte syndrome, as well as severe combined immunodeficiency. Combined immunodeficiencies are commonly distinguished from SCID by low but not absent T-cell function.ICD-9 divides immune deficiencies into three categories: humoral (279.0), cell-mediated (279.1), and combined (279.2). However, ICD-10 does not include a category for cell-mediated immune dysfunction (antibody is D80, and combined is D81), thus grouping T-cell mediated conditions with combined conditions. References


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