نتایج جستجو برای: hydrothermal
تعداد نتایج: 16947 فیلتر نتایج به سال:
Biosorption using agricultural wastes has been proven as a low cost and efficient way for wastewater treatment. Herein, grape peel treated by microwave- and conventional-hydrothermal processes was used as low cost biosorbent to remove methylene blue (MB) from aqueous solutions. The adsorption parameters including the initial pH value, dosage of biosorbents, contact time, and initial MB concentr...
The Upper Jurassic Mantos Blancos copper deposit (500 Mt at 1.0% Cu), located in the Coastal Range of northern Chile, displays two superimposed hydrothermal events. An older phyllic alteration probably related to felsic magmatic–hydrothermal brecciation at ∼155 Ma, and younger (141–142 Ma) potassic, propylitic, and sodic alterations, coeval with dioritic and granodioritic stocks and sills, and ...
the study area covers the northern part of the baft geological map (scale of 1:100 000 ). several porphyry and vein-type mineralization are reported from this area. a topic that is discussed in the mineral exploration community is the use of remote sensing and airborne geophysics for porphyry type mineralization. which one is more reliable and efficient in hydrothermal alteration mapping? airbo...
In analogy with hydrothermal processes on Earth’s seafloor, Martian hydrothermal systems may provide a mechanism for transporting water, chemicals, and energy to the surface. We model magmatic dike driven hydrothermal systems in which we consider changes to the surrounding permeability resulting from the emplacement of the dike (Craft, 2010) and calculate water fluxes to the surface. When compa...
The Loihi hydrothermal plume provides an opportunity to investigate iron (Fe) oxidation and microbial processes in a system that is truly Fe dominated and distinct from mid-ocean ridge spreading centers. The lack of hydrogen sulfide within the Loihi hydrothermal fluids and the presence of an oxygen minimum zone at this submarine volcano’s summit, results in a prolonged presence of reduced Fe wi...
Spectacular black smokers along the mid-ocean-ridge crest represent a small fraction of total hydrothermal heat loss from ocean lithosphere. Previous models of measured heat flow suggest that 40%–50% of oceanic hydrothermal heat and fluid flux is from young seafloor (0.1–5 Ma) on mid-ocean-ridge flanks. Despite evidence that ridge-flank hydrothermal flux affects crustal properties, ocean chemis...
Observations and models of Ceres suggest that its evolution was shaped by interactions between liquid water and silicate rock. Hydrothermal processes in a heated core require both fractured rock and liquid. Using a new core cracking model coupled to a thermal evolution code, we find volumes of fractured rock always large enough for significant interaction to occur. Therefore, liquid persistence...
The shallow marine hydrothermal vents near Ambitle Island in eastern Papua New Guinea discharge hot, slightly acidic, As-rich, chemically reduced fluid into cool, slightly alkaline, oxygenated seawater. Gradients in temperature, pH, and total As (As), among others, are established as the two aqueous phases mix. The hydrothermal fluid contained !900 lg/L As, almost exclusively present as the red...
Hydrothermal zinc oxide (ZnO) thick films were successfully grown on the chemical vapor deposition (CVD)-grown thick ZnO seed layers on a-plane sapphire substrates using the aqueous solution of zinc nitrate dehydrate (Zn(NO3)2). The use of the CVD ZnO seed layers with the flat surfaces seems to be a key technique for obtaining thick films instead of vertically aligned nanostructures as reported...
The vestimentiferan tubeworm Riftia pachyptila (Polychaeta: Sibloglinidae) often dominates early succession stages and high productivity habitats at low-temperature hydrothermal vents on the East Pacific Rise. We collected 8 aggregations of R. pachyptila and the associated epifaunal community at 2 discrete sites of diffuse hydrothermal activity, in December 2001 and December 2002. Because of th...
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