scholarly journals Dynamic evolution of deformation microstructures in rocks. Microstructures and rheology in fault rocks. Frictional behavior and microstructures of quartz gouge at high-temperature hydrothermal conditions.

1996 ◽  
Vol 102 (3) ◽  
pp. 223-231 ◽  
Author(s):  
Kyuichi Kanagawa ◽  
Cox Stephen F.
Keyword(s):  
High Temperature ◽  
Dynamic Evolution ◽  
Hydrothermal Conditions ◽  
Fault Rocks ◽  
Frictional Behavior

scholarly journals Linking the Effect of Aggregate Interaction to the Compaction Theory for Asphalt Mixtures Using Image Processing

2018 ◽  
Vol 8 (11) ◽  
pp. 2045 ◽  
Author(s):  
Kyoungchul Kim ◽  
Myungook Kang
Keyword(s):  
Image Processing ◽  
High Temperature ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Energy Index ◽  
Optimum Temperature ◽  
Frictional Behavior ◽  
Viscosity Effect ◽  
Frictional Interaction ◽  
Compaction Energy

This study presents a modified compaction concept of asphalt mixtures based on aggregate frictional behavior using self-developed image processing for measuring the aggregate orientation. The compaction energy index was introduced to evaluate the aggregate orientation on different compaction temperatures. For the better rearrangement of aggregates, there was an optimum temperature at which a preferred orientation exists, providing lower compaction efforts. An excessively high temperature reduced the asphalt contents for lubrication and caused additional aggregate friction to require higher compaction efforts. This phenomenon can be found in the changes of the volume of the effective asphalt binder (Veac) and the absorbed asphalt binder (Pba). The mixture produced higher Veac, at which an optimum compaction temperature required lower compaction energy. Despite being higher than the optimum temperature for the PG62-28 mixture, the Veac decreased by 0.4%. An increase of 0.35% in the Pba was inferred to flow into the aggregates. Clearly, a reduction of lubricant in the mixture caused a higher frictional interaction between aggregates. Changes in the Veac and the Pba can eliminate the viscosity effect for the rearrangement of aggregates. Based on the aggregate orientation and change in mixture volumetrics, the aggregate interaction effect was introduced to the Mohr–Coulomb compaction theory to explain the additional friction.

HYDROTHERMAL MODELING OF SECONDARY RESERVOIR FORMATI ON IN SILICEOUS LIMESTONS (H2O–CO2 SYSTEM)

2020 ◽  
pp. 43-58
Author(s):  
M. Yu. Zubkov ◽  
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Amorphous Silica ◽  
Hydrothermal Fluid ◽  
West Siberia ◽  
Hydrothermal Conditions ◽  
Secondary Porosity ◽  
First Results ◽  
Siliceous Limestone ◽  
First Time

We have discussed the first results of hydrothermal modeling of the formation of secondary reservoirs (hydrothermal silicites) in siliceous limestones, which are widespread in the Pre-Jurassic complex of West Siberia, namely, in the H2O-CO2 system, in which the mole fraction of CO2 varied from 0.0 to 1.0, and the temperature from 215 to 410оС. It has been found that in this system there is a predominant dissolution of carbonates and, first of all, dolomite, as a result of which the surface of siliceous limestone is silicified and secondary porosity is formed in them. In some samples, quartz microcrystals with varying degrees of perfection of crystal faceting are shaped. It is found that pyrite is also unstable under these hydrothermal conditions and decomposes forming iron-containing carbonates at its sacrifice. Its transformation into pyrrhotite and copper and nickel sulfides is also observed. Biogenic quartz dissolved by a hydrothermal fluid is released from it either in the form of microcrystalline quartz, or in the form of quenching phases represented by cristobalite and/or amorphous silica. It is also found that at temperatures above 360°C, instead of iron-containing carbonates, chlorite is formed due to pyrite, while kaolinite also decomposes along with pyrite. It was experimentally established for the first time that at a high temperature (410°C), carbon dioxide acquires oxidizing properties and, as a result of its interaction with copper, oxide and red oxide of copper are formed. In addition, under these conditions, pyrite passes into iron-containing carbonates rather than chlorite. The main regularities of the formation of secondary reservoirs, i. e. hydrothermal silicites, in the Paleozoic siliceous limestone have been revealed.

Millimeter-sized sodalite single crystals grown under high-temperature, high-pressure hydrothermal conditions

2001 ◽  
Vol 42 (2-3) ◽  
pp. 229-234 ◽  
Author(s):  
Tsuyoshi Shiraki ◽  
Toru Wakihara ◽  
Masayoshi Sadakata ◽  
Masahiro Yoshimura ◽  
Tatsuya Okubo
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystals ◽  
Hydrothermal Conditions ◽  
High Temperature High Pressure

The Influence of the Hydrothermal Conditions on the Morphologies of β-Ni(OH)2

2012 ◽  
Vol 562-564 ◽  
pp. 494-497
Author(s):  
Xiao Ming Fu
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Reaction Time ◽  
Scanning Electron Microscope ◽  
Reaction Temperature ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Low Reaction Temperature ◽  
Scanning Electron

Flower-like β-Ni(OH)2 and nanoflakes have been successfully synthesized with nickel nitrate as nickel source and stronger ammonia water as precipitant via the hydrothermal method. The phase and the morphologies of the samples have been characterized and analyzed by XRD (X-ray diffraction) and SEM (Scanning electron microscope), respectively. XRD shows that the phase of the samples is β-Ni(OH)2. SEM confirms that The low reaction temperature is propitious to the synthesis of flower-like β-Ni(OH)2, and with the increase of the reaction time the nanoflakes of flower-like β-Ni(OH)2 become much thinner. However, The high temperature is in favor of the synthesis of β-Ni(OH)2 nanosflakes, and with the further increase of the reaction temperature.

Ultra-long VO2 (A) nanorods using the high-temperature mixing method under hydrothermal conditions: synthesis, evolution and thermochromic properties

CrystEngComm ◽  
2013 ◽  
Vol 15 (14) ◽  
pp. 2753 ◽  
Author(s):  
Pengcheng Liu ◽  
Kongjun Zhu ◽  
Yanfeng Gao ◽  
Qingliu Wu ◽  
Jinsong Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrothermal Conditions ◽  
Thermochromic Properties ◽  
Mixing Method

scholarly journals Caracterização da Alteração Hidrotermal Micácea do Tipo Greisen e dos Reequilíbrios de Baixa Temperatura em Áreas Graníticas: o Exemplo do Distrito Estanífero de Encruzilhada do Sul, RS

2007 ◽  
Vol 34 (2) ◽  
pp. 75
Author(s):  
ROBERTO DOS SANTOS TEIXEIRA ◽  
JOSÉ CARLOS FRANTZ ◽  
ANDRÉ SAMPAIO MEXIAS ◽  
JULIANA CHARÃO MARQUES ◽  
JORGE ALBERTO COSTA
Keyword(s):  
High Temperature ◽  
White Mica ◽  
Hydrothermal Fluids ◽  
Hydrothermal Conditions ◽  
Quartz Veins ◽  
Upper Limit ◽  
Argillic Alteration ◽  
Granitic Intrusions ◽  
Homogenization Temperatures ◽  
Phyllic Alteration

The hydrothermal alteration associated with the tin mineralization in the Encruzilhada do Sul Tin District is characterized by zones with different compositions. The most important of these hydrothermal zones are the phyllic and the argillic. The first one is composed mainly by white mica and quartz with tourmaline. The argillic alteration is composed by kaolinite. The phyllic zones represent associations with greisens and disseminated pervasive white mica on the granitic wall rocks. The argillic zones are constrained to the top zones of some granitic intrusions associated with greisens and quartz-veins in the stockworks. The hydrothermal fluids associated with the alteration show homogenization temperatures ranging from about 450˚C to 120˚C. The first temperature is the upper limit for the hydrothermal system, related with the white mica high temperature alteration. The second temperature is the lower limit of the argillic alteration under the hydrothermal conditions. The white mica related with the phyllic alteration range from phengite to muscovite. The argillic alteration has the presence of halloysite, probably as a weathering product.

Chelating agents in high temperature aqueous chemistry. 2. The thermal decomposition of some transition metal complexes of nitrilotriacetate (NTA)

1977 ◽  
Vol 55 (10) ◽  
pp. 1770-1776 ◽  
Author(s):  
Meindert Booy ◽  
Thomas Wilson Swaddle
Keyword(s):  
Thermal Decomposition ◽  
High Temperature ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Half Life ◽  
Chelating Agents ◽  
Nuclear Reactors ◽  
Hydrothermal Conditions ◽  
Mechanism Of Decomposition

The kinetics and mechanism of decomposition of NTA complexes of FeIII, FeII, CoII, NiII, and CuII under hydrothermal conditions (425–573 K) have been examined. The relative rates at 573 K are CoIINTA− < NTA3−[Formula: see text] < NiIINTA− < FeIIINTA0 < H3NTA0 < CuIINTA− < H4NTA+. Aqueous CoIINTA− and FeIINTA−, like NTA3−, decomposed at 573 K by decarboxylation, precipitating Co(OH)2 and Fe3O4 respectively; NiIINTA− precipitated Ni(OH)2 initially but subsequently Ni metal. At 530 K, FeIIINTA0 solutions precipitated FeII3(NTA)2•H2O, but at higher temperatures Fe3O4 formed, the NTA ligand being reduced to HCHO and iminodiacetate (IDA) rather than decarboxylated. Similarly, CuIINTA−gave IDA and HCHO at temperatures as low as 425 K, forming first CuI (which precipitated as CuCl in the presence of Cl−) and then metallic Cu. The applicability of NTA to corrosion control in boilers and to 60Co removal from water-cooled nuclear reactors is briefly considered. The half-life of FeIIINTA in the hydrosphere is estimated at 80 years (cf. 8 × 106 years for free NTA), in the absence of photolysis or biodégradation.

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