Cosolvent Influences on Organic Solute Retardation Factors     

Charles A. Staples  Stephanie J. Geiselmann 《Ground water》1988,26(2):192-198

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Radon Distribution in Domestic Water of Texas   总被引：1，自引：0，他引：1  

Irina Cech  Charles Kreitler  Howard Prichard  Alfonso Holguin  Mengistu Lemma 《Ground water》1988,26(5):561-569

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DISCUSSION OF PAPERS     

Charles B. Davis 《Ground water》1988,26(5):649-650

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Prediction of indoor radon by aeroradioactivity     

Douglas G. Mose  Charles Chrosniak  Stephen W. Kline  George W. Mushrush 《Pure and Applied Geophysics》1990,133(2):213-227

Attempts to predict which geographic areas should be associated with a high percentage of homes with unusually high indoor radon levels in Virginia and Maryland have been based on estimates of soil radon and soil permeability for geological units. This method is found to be less successful and probably less cost-effective than the use of total-gamma aeroradioactivity maps.  相似文献   

TOMS measurement of the sulfur dioxide emitted during the 1985 Nevado del Ruiz eruptions     

Arlin J. Krueger  Louis S. Walter  Charles C. Schnetzler  Scott D. Doiron 《Journal of Volcanology and Geothermal Research》1990,41(1-4)

The eruptions of Nevado del Ruiz in 1985 were unusually rich in sulfur dioxide. These eruptions were observed with the Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) which can quantitatively map volcanic sulfur dioxide plumes on a global scale. A small eruption, originally believed to be of phreatic origin, took place on September 11, 1985. However, substantial amounts of sulfur dioxide from this eruption were detected with TOMS on the following day. The total mass of SO₂, approximately 9 ± 3 × 10⁴ metric tons, was deposited in two clouds, one in the upper troposphere, the other possibly at 15 km near the stratosphere.The devastating November 13 eruptions were first observed with TOMS at 1150 EST on November 14. Large amounts of sulfur dioxide were found in an arc extending 1100 km from south of Ruiz northeastward to the Gulf of Venezuela and as an isolated cloud centered at 7°N on the Colombia-Venezuela border. On November 15 the plume extended over 2700 km from the Pacific Ocean off the Colombia coast to Barbados, while the isolated mass was located over the Brazil-Guyana border, approximately 1600 km due east of the volcano. Based on wind data from Panama, most of the sulfur dioxide was located at 10–16 km in the troposphere and a small amount was quite likely deposited in the stratosphere at an altitude above 24 km.The total mass of sulfur dioxide in the eruption clouds was approximately 6.6 ± 1.9 × 10⁵ metric tons on November 14. When combined with quiescent sulfur dioxide emissions during this period, the ratio of sulfur dioxide to erupted magma from Ruiz was an order of magnitude greater than in the 1982 eruption of El Chichon or the 1980 eruption of Mount St. Helens.  相似文献   

Diffusive crystal dissolution     

Youxue Zhang  David Walker  Charles E. Lesher 《Contributions to Mineralogy and Petrology》1989,102(4):492-513

Crystal dissolution may include three component processes: interface reaction, diffusion and complications due to convection. We report here a theoretical and experimental study of crystal dissolution in silicate melt without convection. A reaction-diffusion equation is developed and numerically solved. The results show that during non-convective crystal dissolution in silicate melt, the interface melt composition reaches a constant or stationary saturation composition in less than a second, hence interface reaction is not the rate-determining step and crystal dissolution in silicate melt is usually diffusion-controlled. Crystal dissolution experiments (designed to suppress convection) show that the concentration profiles of all components propagate into the melt according to the square root of run duration, and that the dissolution distance is also proportional to the square root of run duration. Thus our experiments confirm that the dissolution is diffusion controlled, which is consistent with our numerical calculations. For some principal equilibrium-determining components, concentration profiles conform approximately to the analytical solution of the diffusion equation with a constant effective binary diffusion coefficient. Diffusive dissolution rates (which are inversely proportional to square root of time) can thus be predicted from the phase equilibria and the effective binary diffusion coefficients. To predict steady-state convective dissolution rates, the thickness of the boundary layer must be known. If the convective compositional boundary layer thickness around a dissolving crystal aggregate or near the wall of a magma chamber during convection is about 2 cm or larger, then convective dissolution would rarely result in any significant alteration of original melt. Our dissolution experiments also illustrate the complexity of the diffusion process. Uphill diffusion is common, especially during olivine dissolution into andesitic melt where a majority of the components show the effect of diffusion up their own concentration gradients. Uphill diffusion has implications to the understanding of crystal zoning, and suggests caution is required in applying least squares mass balance analysis to magmatic rocks affected by processes involving diffusion.  相似文献   

Journal-isms     

Charles Sheppard 《Marine pollution bulletin》1994,28(12):712-713

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Well Discharge Optimization Using Analytic Elements     

Charles R. Fitts 《Ground water》1994,32(4):547-550

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Effect of sinusoidal interfaces on teleseismic P-wave receiver functions     

Robert H. Clouser  Charles A. Langston 《Geophysical Journal International》1995,123(2):541-558

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Lead and strontium isotopic evidence for crustal interaction and compositional zonation in the source regions of Pleistocene basaltic and rhyolitic magmas of the Coso volcanic field,California     

Charles R. Bacon  Hajime Kurasawa  Maryse H. Delevaux  Ronald W. Kistler  Bruce R. Doe 《Contributions to Mineralogy and Petrology》1984,85(4):366-375

The isotopic compositions of Pb and Sr in Pleistocene basalt, high-silica rhyolite, and andesitic inclusions in rhyolite of the Coso volcanic field indicate that these rocks were derived from different levels of compositionally zoned magmatic systems. The 2 earliest rhyolites probably were tapped from short-lived silicic reservoirs, in contrast to the other 36 rhyolite domes and lava flows which the isotopic data suggest may have been leaked from the top of a single, long-lived magmatic system. Most Coso basalts show isotopic, geochemical, and mineralogic evidence of interaction with crustal rocks, but one analyzed flow has isotopic ratios that may represent mantle values (⁸⁷Sr/⁸⁶Sr=0.7036,²⁰⁶Pb/²⁰⁴Pb=19.05,²⁰⁷Pb/²⁰⁴Pb=15.62,²⁰⁸Pb/²⁰⁴Pb= 38.63). The (initial) isotopic composition of typical rhyolite (⁸⁷Sr/⁸⁶Sr=0.7053,²⁰⁶Pb/²⁰⁴Pb=19.29,²⁰⁷Pb/²⁰⁴Pb= 15.68,²⁰⁸Pb/²⁰⁴Pb=39.00) is representative of the middle or upper crust. Andesitic inclusions in the rhyolites are evidently samples of hybrid magmas from the silicic/mafic interface in vertically zoned magma reservoirs. Silicic end-member compositions inferred for these mixed magmas, however, are not those of erupted rhyolite but reflect the zonation within the silicic part of the magma reservoir. The compositional contrast at the interface between mafic and silicic parts of these systems apparently was greater for the earlier, smaller reservoirs.  相似文献