The condensed polynuclear aromatic clusters of coal are believed to be linked principally by straight-chain aliphatic bridges varying from 0 to 4 carbon atoms in length and the cleavage of these linkages is expected to be an important step in the coal liquefaction process. This study focuses on the means by which Lewis acid catalysts, specifically AlCl/sub 3/ and ZnCl/sub 2/, promote the cleavage of these linkages. To facilitate product identification and interpretation of reaction mechanisms, organic compounds which model the aliphatic bridges were used on substrates. All experiments were performed in a magnetically stirred autoclave under either an H/sub 2/ or N/sub 2/ atmosphere at elevated pressure to determine the role of H/sub 2/. Reaction temperatures ranging from 200 to 350/sup 0/C were used to avoid the complication of pyrolysis reactions. Reaction products were identified with the aid of gas chromatography/mass spectrometry, and quantitative product yields were determined by gas chromatography. Experiments with AlCl/sub 3/ and the substrates containing two phenyl rings linked by 0 to 4 carbon atoms showed that AlCl/sub 3/ catalyzed cleavage of all the aliphatic bridges. ZnCl/sub 2/ was totally inactive in cleaving the alkyl bridges in these compounds. Substitution of a phenyl group by …

The purpose of this paper is to illustrate the use of the computer in solving complex real time scheduling problems. This problem involves the airline industry and is concerned with the local scheduling of security personnel to the gate areas for outgoing flights from one terminal at Dallas-Fort Worth airport. The purpose of this type of program is to enhance personnel efficiency and management control over a large group of people while cutting the cost of lower management.

The scientific subroutine package is one of the most important parts of the software for the scientific industry. By now, most big computers have scientific packages, but applying such a software package in microprocessors requires consideration of the microprocessor's facilities, such as limited main memory, slow execution time, and only a few small registers. In any scientific package, the trigonometric functions are the ones more widely used. This paper discusses a method for implementing several trigonometric function programs in a scientific package in microprocessors. These programs will contain routines for computing sin, cos, tan, and cot of any angle within the range of (-360°,+360°).