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Amorphous hydrogenated carbon films (a‐C : H) containing different amounts of Ti or V were produced by combined plasma‐activated chemical vapour deposition and d.c. magnetron sputtering. New bioactive materials resulted from the combination of the excellent tribological and biological properties of the a‐C : H matrix with the biological response to the incorporated metals. By adding Ti to the a‐C : H matrix, an enhanced differentiation of osteoblast‐ and reduced osteoclast‐like cell activity was achieved, leading to a coating that is valuable for bone implants: enhancing bone ingrowth through increased osteoblast activity and reducing bone resorption through osteoclast‐like cell inhibition. The a‐C : H/V films reduced lysosomal activity as well as neutral red uptake in bone marrow cell cultures, thus being an interesting coating for short‐term implants where reduced cell attachment is required. Prior to cell culture tests, the surfaces of the metal‐containing a‐C : H films were investigated by x‐ray photoelectron spectroscopy. The relation between chemical surface composition and cellular response is discussed. Copyright © 1999 John Wiley & Sons, Ltd.

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A new oil-soluble, filming amine corrosion inhibitor has been developed specifically to treat both sweet and sour corrosion in downhole applications. Its structure contains no amide groups and, thus, is more chemically and thermally stable than the amidoamine and imidazoline-based products widely used in downhole corrosion treating. The new inhibitor has been evaluated both in the laboratory using wheel test screening methods and in the field. The field trial comprised an entire battery of 39 sour producers at the McElroy Field near Crane, Texas, and was conducted over a 14-month period. Laboratory data indicate superior film persistence of formulations of the new amine at lower concentrations, longer times, and higher temperatures than a commercial corrosion inhibitor currently in wide use throughout the Permian Basin and elsewhere. The average batterywide corrosion rate decreased from 2.5 mpy for the commercial inhibitor to 1.6 mpy for the Chevron Amine-based product. In addition, electrochemical Pair probe measurements on batch-treated wells clearly show the improved film persistence of the new material.

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