In the past few decades, chemosynthetic ecosystems at deep-sea hydrothermal vents have received attention as plausible analogues to the early ecosystems of Earth, as well as to extraterrestrial ecosystems. These ecosystems are sustained by chemical energy obtained from inorganic redox substances (e.g., H2S, CO2, H2, CH4, and O2) in hydrothermal fluids and ambient seawater. The chemical and isot...

A hydrothermal method for preparation of nano-size zirconia has been studied to optimize the effective parameters (precursor concentration, temperature and time) using response surface methodology (RSM). The synthesized zirconia samples were characterized through X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) analyses to identify mean nano...

To evaluate possible compositional changes in archaeal communities at a deep-sea hydrothermal vent field scale, we examined five different samples obtained after deploying in situ collectors for different times on three spatially separated venting sulphide structures on the East Pacific Rise (13 ∞ N). Direct cell counts and whole-cell hybridizations with fluorescently labelled 16S rRNA-based ol...

The Lost City Hydrothermal Field, an ultramafic-hosted system located 15 km west of the Mid-Atlantic Ridge, has experienced at least 30,000 years of hydrothermal activity. Previous studies have shown that its carbonate chimneys form by mixing of approximately 90 degrees C, pH 9-11 hydrothermal fluids and cold seawater. Flow of methane and hydrogen-rich hydrothermal fluids in the porous interior...

Shea, M. and Foland, K.A., 1986. The Marysvale Natural Analog Study: Preliminary oxygen isotope relations. In: N.A. Chapman and J.A.T. Smellie (Guest-Editors), Natural Analogues to the Conditions around a Final Repository for High-level Radioactive Waste. Chem. Geol., 55: 281--295. Rocks of and around the Marysvale mining area in central Utah, U.S.A., have experienced massive, subsolidus hydrot...

BACKGROUND Hydrothermal pretreatment of lignocellulosic biomass such as rice straw can dissolve part of the lignin and hemicellulose into a liquid fraction, thus facilitating enzyme accessibility to cellulose in bioethanol production process. Lignin is awaited to be recovered after hydrothermal pretreatment for utilization as value-added chemical, and lignin recovery also means removal of ferme...

UNLABELLED BACKGROUND The impact of hydrothermal flowthrough (FT) pretreatment severity on pretreatment and solubilization performance metrics was evaluated for three milled feedstocks (corn stover, bagasse, and poplar) and two conversion systems (simultaneous saccharification and fermentation using yeast and fungal cellulase, and fermentation by Clostridium thermocellum). RESULTS Compared...

Amygdaloidal, cavity- and fracture-filling zeolites in Eocene volcanic rocks from the Kuh-e-Aradeh of southern Kahrizak, in the northernmost part of Central Iran have been studied in some detail by optical, chemical analysis, SEM, and XRD techniques. The zeolites identified, in order of their relative time of formation from early to late, are tetranatrolite, analcime, natrolite, mesolite, stilb...

An in situ time-resolved X-ray diffraction (XRD) system for hydrothermal reaction has been developed in order to investigate the phase evolution during autoclave process in autoclaved aerated concrete (AAC) formation. The system includes a novel autoclave cell for transmission XRD with thin beryllium windows, a two-dimensional photon-counting pixel array detector, and uses high energy X-rays fr...