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Hydrogenated carbon (CH x ) films were grown by reactive magnetron sputtering of graphite in an argon–hydrogen plasma. Pulsed d.c. bias was applied to both the carbon target and the substrate to maintain a stable process and reasonable deposition rate. The resulting films were smooth and stress-free. The influence of hydrogen concentration and relative humidity on friction properties of the films was investigated. At 5% relative humidity, the lowest friction coefficient of 0.01 was obtained at a sputter-gas composition containing 25% hydrogen. Excessive incorporation of hydrogen produces softening and degrades its friction performance at high contact stresses. Molecular dynamics simulation studies showed the reduction of friction coefficient with surface hydrogenation. These studies indicate that pulsed d.c. magnetron sputtering can produce hydrogenated carbon films with friction properties similar to those prepared by chemical vapor deposition methods.

Cultured human hepatocytes are a valuable in vitro system for evaluating new molecular entities as inducers of cytochrome P450 (P450) enzymes. The present study summarizes data obtained from 62 preparations of cultured human hepatocytes that were treated with vehicles (saline or dimethylsulfoxide, 0.1%), beta-naphthoflavone (33 microM), phenobarbital (100 or 250 microM), isoniazid (100 microM) and/or rifampin (20 or 50 microM), and examined for the expression of P450 enzymes based on microsomal activity toward marker substrates, or in the case of CYP2C8, the level of immunoreactive protein. The results show that CYP1A2 activity was markedly induced by beta-naphthoflavone (on average 13-fold, n = 28 preparations), and weakly induced by phenobarbital (1.9-fold, n = 25) and rifampin (2.3-fold, n = 22); CYP2A6 activity tended to be increased with phenobarbital (n = 7) and rifampin (n = 3) treatments, but the effects were not statistically significant; CYP2B6 was induced by phenobarbital (6.5-fold, n = 13) and rifampin (13-fold, n = 14); CYP2C8 was induced by phenobarbital (4.0-fold, n = 4) and rifampin (5.2-fold, n = 4); CYP2C9 was induced by phenobarbital (1.8-fold, n = 14) and rifampin (3.5-fold, n = 10); CYP2C19 was markedly induced by rifampin (37-fold, n = 10), but relatively modestly by phenobarbital (7-fold, n = 9); CYP2D6 was not significantly induced by phenobarbital (n = 5) or rifampin (n = 5); CYP2E1 was induced by phenobarbital (1.7-fold, n = 5), rifampin (2.2-fold, n = 5), and isoniazid (2.3-fold, n = 5); and, CYP3A4 was induced by phenobarbital (3.3-fold, n = 42) and rifampin (10-fold, n = 61), but not by beta-naphthoflavone. Based on these observations, we generalize that beta-naphthoflavone induces CYP1A2 and isoniazid induces CYP2E1, whereas rifampin and, to a lesser extent phenobarbital, tend to significantly and consistently induce enzymes of the CYP2A, CYP2B, CYP2C, CYP2E, and CYP3A subfamilies but not the 2D subfamily.

Electric power production from wind turbines has increased substantially during the past few years due to the growing emphasis on renewable energy sources and more efficient wind turbine technology. Although modern turbines are significantly quieter than early models, wind farms that are proposed near residential areas generate concern about potential noise issues. The present study consists of two parts: (1) the measurement of sound levels within a 2‐km radius of the existing Nine Canyons wind farm near Richland, WA, and (2) the application of an outdoor sound propagation model to predict noise levels, both at Nine Canyons and in the vicinity of a proposed farm near Ellensburg, WA. At most locations within the Nine Canyon site, recorded sound levels were less than predicted levels, with the exception of some downwind sites that were lower in elevation than the source. Noise levels were greatest downwind from the turbines, but never exceeded 50 dBA beyond 500 m from the nearest turbine. In many cases, wind noise at the microphone exceeded noise levels from the turbines.