Poisons, in general

Inhalation is the most common means by which ethers enter the body. The effects of various ethers may include narcosis, irritation of the nose, throat, and mucous membranes, and chronic or acute poisoning. In general, ethers are central nervous system depressants, eg, ethyl ether and vinyl ether are used as general anesthetics. 

Philosophically, one must decide when to term Component C an adsorbing species and when to call it a poison. In general, a poison is seen as a case where a very small concentration of C has a large effect on the reaction rate otherwise, it is simply a competitively adsorbing species that is typical of all solid-catalyzed reactions. 

Other studies reveal similar results. They show that ammonia levels as low as 0.3 ppm in the hydrogen stream negatively affect the fuel cell over time [8]. Recovery seems possible in the case of ammonia poisoning. In general, performance increases when the fuel cell is switched to pure hydrogen feed streams. This is likely because ammonium ions have a mechanism to... 

The reaction uses a catalyst, typically an iron catalyst. Magnetite ( 6304) is used with other oxides such as alumina, calcium oxide, potassium oxide, magnesium oxide and silica. The magnetite is reduced in the process to the active iron catalyst [23]. Alumina acts as a structural stabilizer and gives improved surface area in the catalyst. Particle size must be balanced. Smaller particles are more effective catalysts but very small particles can cause pressure drops through the reactor. Certain substances may interfere with the catalyst. These are called poisons. In general, a catalyst that is resistant to poisons is desirable, but there must still be efforts to exclude poisons from the reactor feed. 

General Safety Aspects. Whereas cyanides have become infamous as poisons in part because of the use in prison execution chambers, Na2i death camps, and in over-the-counter dmg tampering cases, there is worldwide safe production of nearly one million t annually. 

Association of Industrial Activity and Poisonings in the General Environment... 

Dioscorine is bitter and poisonous it produces paralysis of the centra system, and, in general, behaves like picrotoxin. This action PPears to be correlated with the — 0—C = C- group, since on the... 

This tree occurs widely distributed in Africa and the bark is known under a variety of native names, e.g., sassy bark in West Africa, where it was formerly used as an ordeal poison in East and Central Africa it is said to have been an ingredient in arrow-poisons. The bark was first examined by GaUois and Hardy who isolated a toxic alkaloid, erythrophleine, which- was examined by Hamack and Zabrocki and later by Hamack, whose results differed from those of Gallois and Hardy and were generally confirmed by Power and Salway. Recently interest... 

In general, mercaptans are more malodorous than sulfides and hydrogen sulfide. The presence of significant amounts of sulfur can induce catalyst poisoning during the refining of crude oil. 

Deactivation of zeolite catalysts occurs due to coke formation and to poisoning by heavy metals. In general, there are two types of catalyst deactivation that occur in a FCC system, reversible and irreversible. Reversible deactivation occurs due to coke deposition. This is reversed by burning coke in the regenerator. Irreversible deactivation results as a combination of four separate but interrelated mechanisms zeolite dealu-mination, zeolite decomposition, matrix surface collapse, and contamination by metals such as vanadium and sodium. 

Ethylene glycol is common in automotive antifreeze mixtures. Because of its toxicity, it is sometimes replaced by propylene glycol, which is FDA approved for use in food, and is considered generally accepted as safe. Ethylene glycol has a sweet taste, and accidental poisoning in children is a danger. 

Some of the economic problems that confront the chemical industry and some practical problems of agriculture and society in general, resulting from the use of newer economic poisons, are discussed. Above all else, more facts are needed upon which to base both present procedures and future studies. 

Excellent cooperation has been received from the United States Department of Agriculture and state agricultural experiment stations in carrying out field tests with this material. Without such cooperation this important economic poison would not be in general tise at this time. 

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