Role of H2O in Oxidative Regeneration of ZnS Formed from High-Temperature Desulfurization ZnO Sorbent

2000 ◽  
Vol 39 (10) ◽  
pp. 3844-3848 ◽  
Author(s):  
Eiji Sasaoka ◽  
Makoto Hatori ◽  
Norimasa Sada ◽  
Md. Azhar Uddin
Keyword(s):  
High Temperature ◽  
Oxidative Regeneration

scholarly journals The Role of Chromium in Iron-based High-Temperature Water-Gas Shift Catalysts under Industrial Conditions

2021 ◽  
pp. 120465
Author(s):  
M.I. Ariëns ◽  
V. Chlan ◽  
P. Novák ◽  
L.G.A. van de Water ◽  
A.I. Dugulan ◽  
...  
Keyword(s):  
High Temperature ◽  
Water Gas Shift ◽  
High Temperature Water ◽  
Iron Based ◽  
Water Gas ◽  
Temperature Water

Microstructure of high-temperature (>73 °C) siliceous sinter deposited around hot springs and geysers, Yellowstone National Park: the role of biological and abiological processes in sedimentation

2003 ◽  
Vol 40 (11) ◽  
pp. 1611-1642 ◽  
Author(s):  
Donald R Lowe ◽  
Deena Braunstein
Keyword(s):  
High Temperature ◽  
Yellowstone National Park ◽  
National Park ◽  
Hot Springs ◽  
Strain Effect ◽  
Temperature Sinter ◽  
Architectural Features ◽  
Siliceous Sinter ◽  
High Temperature Sinter

Slightly alkaline hot springs and geysers in Yellowstone National Park exhibit distinctive assemblages of high-temperature (>73 °C) siliceous sinter reflecting local hydrodynamic conditions. The main depositional zones include subaqueous pool and channel bottoms and intermittently wetted subaerial splash, surge, and overflow areas. Subaqueous deposits include particulate siliceous sediment and dendritic and microbial silica framework. Silica framework forms thin, porous, microbe-rich films coating subaqueous surfaces. Spicules with intervening narrow crevices dominate in splash zones. Surge and overflow deposits include pool and channel rims, columns, and knobs. In thin section, subaerial sinter is composed of (i) dark brown, nearly opaque laminated sinter deposited on surfaces that evaporate to dryness; (ii) clear translucent silica deposited subaqueously through precipitation driven by supersaturation; (iii) heterogeneous silica representing silica-encrusted microbial filaments and detritus; and (iv) sinter debris. Brownish laminations form the framework of most sinter deposited in surge and overflow zones. Pits and cavities are common architectural features of subaerial sinter and show concave-upward pseudo-cross-laminations and micro-unconformities developed through migration. Marked birefringence of silica deposited on surfaces that evaporate to dryness is probably a strain effect. Repeated wetting and evaporation, often to dryness, and capillary effects control the deposition, morphology, and microstructure of most high-temperature sinter outside of the fully subaqueous zone. Microbial filaments are abundant on and within high-temperature sinter but do not provide the main controls on morphology or structuring except in biofilms developed on subaqueous surfaces. Millimetre-scale lamination cyclicity in much high-temperature sinter represents annual layering and regular seasonal fluctuations in silica sedimentation.

The role of π-bonding on the high temperature structure of the double perovskites Ba2CaUO6and BaSrCaUO6

2015 ◽  
Vol 44 (36) ◽  
pp. 16036-16044 ◽  
Author(s):  
Emily Reynolds ◽  
Gordon J. Thorogood ◽  
Maxim Avdeev ◽  
Helen E. A. Brand ◽  
Qinfen Gu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Neutron Diffraction ◽  
Temperature Structure ◽  
Double Perovskites ◽  
Phase Transition Behavior ◽  
X Ray ◽  
Progressive Loss ◽  
Octahedral Tilting

High temperature synchrotron X-ray and neutron diffraction powder diffraction studies of the uranium perovskites Ba2CaUO6and BaSrCaUO6reveal unusual phase transition behavior associated with the progressive loss of cooperative octahedral tilting.

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