Fifty , importance

Through the work of especially Goldfarb et al. but also of Buu-Hoi et al., Badger et al., and Wynberg et al., the Raney nickel desulfurization of thiophenes has been developed to an important tool for the synthesis of aliphatic compounds. During the last 5 years over fifty papers have appeared describing applications of this method. 

The raw materials needed to supply about ten million new automobiles a year do not impose a difficult problem except in the case of the noble metals. Present technology indicates that each car may need up to ten pounds of pellets, two pounds of monoliths, or two pounds of metal alloys. The refractory oxide support materials are usually a mixture of silica, alumina, magnesia, lithium oxide, and zirconium oxide. Fifty thousand tons of such materials a year do not raise serious problems (47). The base metal oxides requirement per car may be 0.1 to 1 lb per car, or up to five thousand tons a year. The current U.S. annual consumption of copper, manganese, and chromium is above a million tons per year, and the consumption of nickel and tungsten above a hundred thousand tons per year. The only important metals used at the low rate of five thousand tons per year are cobalt, vanadium, and the rare earths. 

This contribution to the broad field of organosilicon chemistry including molecules and materials, marks a very unusual anniversary, the existence of which effectively contradicts a historical statement by the famous organosilicon pioneer F. S. Kipping, who believed 80 years ago that organosilicon chemistry would never gain industrial and commercial importance. Fifty years after the invention of the Miiller-Rochow process, the silicon industry achieved an annual worldwide turnover of US 4.700.000.000. This proves impressively that the basic process - independently developed by R. Muller and E. G. Rochow in 1941/2 - can be considered to be the most important innovation for organosilicon research work in industry and university. 

You keep going back to that one meeting," I said to Minskoff. "I just don t understand why that meeting is so important, and why are those particular fifty doses of vaccine so important "... 

We were quite elated, and it appeared that it was a rich field. Now, fifty years later, I must say that it wasn t as rich as we thought. But we have over the years discovered half a dozen natural radioactive elements, and two of these, the samarium-147 with its decay to neodymium-143 and rhenium-187 with its decay to osmium-187, prove to be of use in Nuclear Dating. The importance of rhenium is that it is iron soluble while the other radioactivities are insoluble in metallic iron. In fact, the best half life we have for rhenium-187 was obtained by measuring the osmium-187 to rhenium-187 ratio in iron meteorites which had been dated by other methods. This work was started many years ago by Dr. Herr and others in Germany. The half life is 43,000,000,000 years. 

Another important development in the field was the discovery of the vapor-phase nitration in the 1930s by H. Hass and his students at Purdue University. It led in 1940 to the commercial production of lower molecular weight nitroalkanes [Cl to C4] at a pilot plant of the Commercial Solvents Corporation in Peoria, Illinois. In the organic nitro chemistry era of the fifties and early sixties, a great emphasis of the research was directed towards the synthesis of new compounds that would be useful as potential ingredients in explosives and propellants. 

In this lofty position, he has for nearly fifty years followed and often guided the research efforts of so many workers that his label, "everything to everybody" takes on real meaning. With his breadth of contacts and genuine interest in people and his ability to communicate with interested audiences of almost any level of knowledge, he has been and remains one of the most liked, visible, important leaders in science. 

No releases of 3,3 -diehlorobenzidine to the surface water were reported in 1996 (TR196 1998). Two hundred and fifty pounds (550 kilograms) were released to publiely owned treatment works (POTWs) (TR196 1998). These releases are summarized in Table 5-1. The TRl data should be used with eaution beeause only certain types of facilities are required to report information to the Toxies Release Inventory only if they employ more than 10 full-time employees, if their faeility is elassified under Standard Industrial Classification (SIC) codes 20 through 39, and if their faeility produees, imports, or proeesses 25,000 or more pounds of any TRl chemical or otherwise used more than 10,000 pounds of a TRl ehemical in a calendar year (EPA 1997). As a result of secondary treatment proeesses in POTWs, only a small percentage of any 3,3 -dichlorobenzidine that might enter POTWs is subsequently released into surface water. 

Fifty years after the introduction of catalytic hydrogenation into the methodology of organic chemistry another discovery of comparable importance was published synthesis [82] and applications [55] of lithium aluminum hydride and lithium and sodium borohydride. 

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