In the field of heterogeneous catalysis. it is convenient to distinguish. in a perfectly unjustified and over..simplified way. bet: leen metal catalysts. 2nd the other catalysts. The fj.J"st are easy to define: they are those in which a reduced metal is the active phase. It is thus easy to circumscribe. by exclusion, the other class namely the "non-metals." We have adopted this definition for the sake of our colleagues working on catalysis by metals, and to avoid a lengthy title like "sm' face pl"operties and catalysts by transi tion metal oxides. sulftdes, carbides, nitriles, etc. Defined in...

Proceedings of the NATO Advanced Study Institute, Dundee, Scotland, August 17-September 6, 1986

The optical studies of fossil organic matter in reflected light have made great progress in recent decades with the development of coal petrology, completed around the end of the 1970s by fluorescence examination. As they are complementary to the studies in transmitted light (palynology) and organic geochemistry developed for petroleum exploration purposes, they have become a much used tool in the recognition of sedimentary thermal transformations. For more than fifteen years within the Elf-Aquitaine Group, these studies have been applied in their various aspects to furnish a better...

Manganese nodules were first discovered on the ocean floor 160 miles south-west of the Canary Islands on February 18, 1803, during the first complex oceano logical cruise of the Challenger. They surprised researchers by their unusual shape and also by their unusual chemical composition; nevertheless for many years after wards, they were considered merely as one of Nature's exotic marine tricks. After the Secpnd World War, a comprehensive investigation of the World Ocean started, and new data were obtained on a wide distribution of manganese nodules and their polymetallic composition, that...

The monograph presented to foreign readers has been prepared by the famous Soviet investigators of processes of geochemistry and sedimentation in the Mediterranean Sea. For more than 20 years E.M. Emelyanov has examined the recent sedimentation of the Mediterranean Sea and K.M. Shimkus has studied the Quaternary and the earlier sedi mentation of the area. The authors, scientific workers from the P.P. Shirshov Institute of Oceanology, USSR Academy of Sciences (Atlantic and Southern Depart ments), took part not only in numerous cruises on oceanographic vessels of the USSR, but in the study of...