Poison gases definition

Much of the initial development of Gaussian modeling and definition of dispersion paramenters was done during and after World War I in addressing the problem of poison gas dispersal. These studies involved the definition of risk factors, such as exposure and dose. The next intensive development effort came during and after World War II with the nuclear weapons program. 

The DOT definition of poison gas is a material that is a gas at 68°F or less at 14.7 psi and is so toxic to humans as to pose a hazard to health during transportation, or in the absence of adequate data on human toxicity, is presumed to be toxic to humans because when tested on laboratory animals it has an LC50 value of not more than 5000 ml/m. These materials are considered so toxic that, when transported, the vehicle must be placarded regardless of the quantity. The potential exists for 2.3 materials to affect large populations by creating toxic gas clouds, hi order to understand the... 

Unable to provide definitive answers to most of these questions, chemical warfare specialists continued to repeat what we have already heard that a single whiff of a nerve gas such as sarin, or a single drop of a liquid nerve agent such as VX can be fatal. They incorrectly warn us that an enemy can pack enough such poison into a single missile warhead to annihilate thousands of people, perhaps the population of an entire city. They note that even the skin can be penetrated, but then tell us it is even more important to possess an airtight mask. 

Sinee water was shown to be a poison for Cu-ZSM-5, it is espeeially important to examine the effeet of water vapor on the activity of Cu-Al-MCM-41 in NO-SCR. A full study is currently undertaken in our laboratory. Figm-e 35 shows the dynamie effeet of introdueing 10% H2O in the feed, on eatalytic activity at 400 °C. The deerease in NO eonversion was sensible but still not very high and by sequential suppression of the water in the gas feed the effect was found to be reversible. The low and reversible deactivation by water vapor during NO-SCR is also signifieant for potential commereial application of these new eatalysts. The surface chemistry of the support, its hydrophilieity, will require investigations before any definitive conclusion can be made. 

The oxidation of CO on the surface of hopcalite is a reaction of zero order. Both a stoichiometric process resulting in the reduction of the oxide surface and a catalytic process with oxygen of the gas phase have been observed. The heat of activation for the catalytic process varies for different samples of hopcalite within the limits of 5 to 7 kcal. (64). Poisoning of the hopcalite surface by adsorption of water vapor is independent of the temperature. The catalytic reaction takes place on a definite and constant part of the surface and no additional active sections of surface are brought in to play if the temperature is increased. From a determination of the heats of wetting of water on hopcalite, it is apparent that the surface can be subdivided into two types with different heats of wetting (64). 

Within the Fischer-Tropsch research ECN Biomass concentrates on the definition of the gas cleaning with respect to the typical B R in urities, like NHj, HCl, HCN, H]S, COS, tars (heavy organic molecules), soot, and alkali metals, Traces (< ppm) of these compounds can already be a poison for the Fischer-Tropsch catalysts. For the implementation of B R and Fischer-Tropsch ECN its strategy is on the demonstration of integrated systems to reduce the time necessary to realise a first full-scale installation for conversion of biomass and residue, gas cleaning, and Fischer-Tropsch synthesis. To achieve this ECN focuses on two lines of development ... 

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