It is primarily produced by combining water and propene in a hydration reaction or by hydrogenating acetone. In 1994, 1.5 million tonnes of isopropyl alcohol were produced in the United States, Europe, and Japan. Isopropyl alcohol was oxidized to acetone for the preparation of cordite, a smokeless, low explosive propellant. In 1920, Standard Oil first produced isopropyl alcohol by hydrating propene. The reaction with aluminium is initiated by a trace of mercury to give aluminium isopropoxide. This and similar reactions are often conducted in the presence of base. With titanium tetrachloride, isopropyl alcohol reacts to give titanium isopropoxide: Like most alcohols, isopropyl alcohol reacts with active metals such as potassium to form alkoxides that are called isopropoxides. Isopropyl alcohol may be converted to 2-bromopropane using phosphorus tribromide, or dehydrated to propene by heating with sulfuric acid.
Isopropyl alcohol is often used as both solvent and hydride source in the Meerwein-Ponndorf-Verley reduction and other transfer hydrogenation reactions. This can be achieved using oxidizing agents such as chromic acid, or by dehydrogenation of isopropyl alcohol over a heated copper catalyst: Isopropyl alcohol can be oxidized to acetone, which is the corresponding ketone. Isopropyl alcohol has a maximal absorbance at 205 nm in an ultraviolet- visible spectrum. Isopropyl alcohol becomes increasingly viscous with decreasing temperature and freezes at −89 ☌ (−128 ☏). It has a slightly bitter taste, and is not safe to drink. Alcohol mixtures have depressed melting points. Isopropyl alcohol forms an azeotrope with water, which gives a boiling point of 80.37 ☌ (176.67 ☏) and a composition of 87.7% by mass (91% by volume) isopropyl alcohol. The process is colloquially called salting out, and causes concentrated isopropyl alcohol to separate into a distinct layer. Unlike ethanol or methanol, isopropyl alcohol is not miscible with salt solutions and can be separated from aqueous solutions by adding a salt such as sodium chloride. It dissolves ethyl cellulose, polyvinyl butyral, many oils, alkaloids, and natural resins. Expert systems that do not make use of fuzzy theory are the main current, but of the almost 2000 expert systems reported, only about 2% are actually being used.Isopropyl alcohol is miscible in water, ethanol, and chloroform as, like these compounds, isopropyl is a polar molecule. There are few examples of fuzzy expert systems outside of control, but there are reports of fault analysis systems for locomotives and restaurant menu selection systems.
The manner in which experts think can be said to be thinking that involves collection and management of knowledge for the solving of specific problems but can be seen as a miniature of human thinking and humans in general. The ways that experts do things involves the manner in which they bring together knowledge and their way of thinking, and this in its turn is nothing other than the way human beings think. Expert systems are systems that imitate the ways that the knowledge of such systems is expressed and used methods for effectively constructing expert systems must accurately incorporate the ways in which experts perform. These systems can be thought of as one of the fields of application of artificial intelligence. This chapter describes the elements and applications of expert systems.
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