نتایج جستجو برای: hydrothermal alterations

تعداد نتایج: 127690  

Journal: :زمین شناسی اقتصادی 0
محمد ابراهیمی حسین کوهستانی احسان شهیدی

introduction mesgar iron occurrence is located in northwestern part of the central iran, 115 km south of zanjan. although there is a sequence of volcanic-pyroclastic rocks accompanied by iron mineralization, no detailed works had been conducted in the area. the present paper provides an overview of the geological framework, the mineralization characteristics, and the results of geochemical stud...

2016
James D Flynn Hisako Hirayama Yasuyoshi Sakai Peter F Dunfield Martin G Klotz Claudia Knief Huub J M Op den Camp Mike S M Jetten Valentina N Khmelenina Yuri A Trotsenko J Colin Murrell Jeremy D Semrau Mette M Svenning Lisa Y Stein Nikos Kyrpides Nicole Shapiro Tanja Woyke Françoise Bringel Stéphane Vuilleumier Alan A DiSpirito Marina G Kalyuzhnaya

The genome sequences of Methylobacter marinus A45, Methylobacter sp. strain BBA5.1, and Methylomarinum vadi IT-4 were obtained. These aerobic methanotrophs are typical members of coastal and hydrothermal vent marine ecosystems.

Hydrothermal and non-hydrothermal spherical TiO2 nanoporous with crystalline framework were prepared by sol-gel method. The Crystalline structures, morphologies and surface texturing of materials were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 adsorption-desorption isotherms. The Hydrothermal spherical TiO2 nanoporous was found to have a narrow and strong p...

Journal: :Journal of bacteriology 2011
Xingna Wang Zhaoming Gao Xun Xu Lingwei Ruan

Thermococcus sp. strain 4557 is a hyperthermophilic anaerobic archaeon isolated from the deep-sea hydrothermal vent Guaymas Basin site in the Gulf of California at a depth of 2,000 m. Here, we present the complete genome sequence of Thermococcus sp. 4557, which consists of a single circular chromosome of 2,011,320 bp with a G+C content of 56.08%.

Journal: :Applied and environmental microbiology 2003
Mausmi P Mehta David A Butterfield John A Baross

The subseafloor microbial habitat associated with typical unsedimented mid-ocean-ridge hydrothermal vent ecosystems may be limited by the availability of fixed nitrogen, inferred by the low ammonium and nitrate concentrations measured in diffuse hydrothermal fluid. Dissolved N2 gas, the largest reservoir of nitrogen in the ocean, is abundant in deep-sea and hydrothermal vent fluid. In order to ...

2014
Shaoni Sun Xuefei Cao Shaolong Sun Feng Xu Xianliang Song Run-Cang Sun Gwynn Lloyd Jones

BACKGROUND The recalcitrance of lignocellulosic biomass is a major limitation for its conversion into biofuels by enzymatic hydrolysis. The use of a pretreatment technology is an essential step to diminish biomass recalcitrance for bioethanol production. In this study, a two-step pretreatment using hydrothermal pretreatment at various temperatures and alkali fractionation was performed on eucal...

Journal: :پژوهش های تولید گیاهی 0
ابوالفضل درخشان جاوید قرخلو

the hydrothermal time models have been widely applied to describe the germination responses of seeds to temperature and water potential. in this study, three hydrothermal time models developed on the basis of different statistical distributions (normal, weibull and gumbel) were compared to describe the phalaris minor seed germination. results showed that gumbel (aicc=-762.8) and weibull (aicc=-...

2000
M. Sharma

We present Os data for axial high-temperature and off-axial low-temperature hydrothermal solutions from the Juan de Fuca Ridge. The high-temperature, H2S-bearing axial fluids have unradiogenic Os isotopes pointing to a nearly complete domination of osmium isotopes from the basalts during hydrothermal circulation. The ridge axis fluids typically do not show large enrichment in osmium concentrati...

2006
Giora Proskurowski Marvin D. Lilley Deborah S. Kelley Eric J. Olson

Although commonly utilized in continental geothermal work, the water–hydrogen and methane–hydrogen isotope geothermometers have been neglected in hydrothermal studies. Here we report δD-CH4 and δD-H2 values from high-temperature, black smoker-type hydrothermal vents and low-temperature carbonate-hosted samples from the recently discovered Lost City Hydrothermal Field. Methane deuterium content ...

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