Results 41 to 50 of about 83,496 (259)

The Effect of Demineralization on Coal Functional Group Pyrolysis: Rank‐Dependent Dual Mechanisms of Structural Reorganization and Mineral Catalysis

open access: yesAsia-Pacific Journal of Chemical Engineering, EarlyView.
ABSTRACT Coal pyrolysis, as a key thermochemical conversion process, is significantly influenced by inherent minerals, yet their role across different coal ranks remains inadequately understood. This study investigates the effect of acid‐washing (demineralization) on the thermal decomposition of six functional groups (aliphatic C–H, aromatic C–H/C=C, C=
Zhiyuan Niu   +4 more
wiley   +1 more source

Selenium and tellurium concentrations of Carboniferous British coals [PDF]

open access: yes, 2019
The authors wish to thank Kier Group, the British Coal Utilisation Research Association (BCURA) and Uniper (E.On) for kindly providing coal samples.
Armstrong, Joseph   +7 more
core   +1 more source

Histology and fossil diagenesis of a pterosaur tooth from the Crato Formation (Lower Cretaceous of Brazil)

open access: yesThe Anatomical Record, EarlyView.
Abstract Pterosaur dental biology remains poorly understood despite its importance for comprehending feeding strategies and flight adaptations. Here, we present the first comprehensive histological analysis of an ornithocheiriform pterosaur tooth from the Lower Cretaceous Crato Formation (Santana Group, Northeast Brazil).
Tito Aureliano   +3 more
wiley   +1 more source

Sunflower structure of pyrite in Lignite of Western Kachchh, Gujarat (India): Insights on its origin and mechanism

open access: yesInternational Journal of Coal Science & Technology
Textural analysis of pyrite has been carried out in the lignites of Kachchh Basin to decipher its micro-morphological character. The study entails the intermediate stage and authigenic sunflower structured pyrite.
Ashish Kumar Singh   +3 more
doaj   +1 more source

Study on Water Wettability Mechanism of Pyrite and Coal Surfaces Based on Density Functional Theory

open access: yesKuangchan zonghe liyong, 2022
Flotation is based on the difference of wettability of mineral surfaces. In order to study the water wettability mechanism of pyrite and coal surfaces, pyrite and perfect coal surface models were constructed. The adsorptions of water and oxygen molecules
Chengyong Wang   +3 more
doaj   +1 more source

Geological and geotechnical challenges on the Great Dyke of Zimbabwe and their impact on hardrock pillar design

open access: yesDeep Underground Science and Engineering, EarlyView.
The Great Dyke of Zimbabwe is notable for its rich platinum group metal deposits but poses significant geological and geotechnical challenges due to its complex rock types and structural features. Traditional pillar design methods are insufficient for addressing these complexities; the study suggests incorporating advanced techniques such as machine ...
Tawanda Zvarivadza   +3 more
wiley   +1 more source

Microscopic characteristics and geological significance of pyrite in shales of the Wufeng-Longmaxi formations, southeastern Chongqing, China

open access: yesEnergy Geoscience
Shales of the Wufeng-Longmaxi formations in the basin-margin transition zone of southeastern Chongqing, China are characterized by high organic matter content and a significant presence of pyrite development.
Xiao Cai   +8 more
doaj   +1 more source

A rock brittleness index based on the postpeak energy release rate and damage surface characteristics for brittle hard rock

open access: yesDeep Underground Science and Engineering, EarlyView.
This study examines energy evolution in rock rupture via triaxial direct shear tests, exploring the impact of confining pressure and temperature on fracture surface randomness. A novel energy‐based brittleness index is proposed, validated experimentally, and compared with existing methods for reliability and accuracy.
Biao Wang   +5 more
wiley   +1 more source

A feasibility study towards ultra-thin PV solar cell devices by MOCDV based on a p-i-n structure incorporating pyrite [PDF]

open access: yes, 2010
FeSx layers were deposited onto aluminosilicate glass substrates over a temperature range of 180°C to 500°C using a horizontal AP-MOCVD reactor. Fe(CO)5 was used as the Fe source in combination with t-Bu2S2 or t-BuSH as S precursor to control the rate of
Barrioz, Vincent   +5 more
core  

Surface hydration‐induced damage in tight oil‐bearing sandy conglomerate reservoirs

open access: yesDeep Underground Science and Engineering, EarlyView.
A series of techniques such as X‐ray diffraction, scanning electron microscopy, energy‐dispersive spectroscopy, conductivity tests, and infrared thermal imaging were used. The key findings are the identification of a two‐stage surface hydration process and the elucidation of the effects of various minerals and elements on the hydration process ...
Anbang Zhao   +5 more
wiley   +1 more source

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