Results 51 to 60 of about 34,282 (303)

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

Deep 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, Zaobao Liu, Jing Xue, Bo Lu, Wei Zeng, Dengke Zhang   +5 more
wiley   +1 more source

The incrementally zoned Miocene Ayagaures ignimbrite (Gran Canaria, Canary Islands) [PDF]

, 2010
The 20–25 m thick trachyphonolitic Ayagaures ignimbrite cooling unit [(AY); 11.8 Ma] exposed over 250 km2 (onshore volume ca. 4.5 km3 DRE) is the uppermost and most voluminous cooling unit of the Middle Fataga Formation (MFF), part of the Fataga Group ...
Hans-Ulrich Schmincke, Schmincke, Hans-Ulrich, Jutzeler, Martin, Martin Jutzeler, Sumita, Mari, Mari Sumita   +5 more
core   +1 more source

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

Deep 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, Shuheng Du, Yuan Zhang, Jinghong Hu, Bo Zhou, Yun Wei   +5 more
wiley   +1 more source

Numerical and experimental study on P‐wave propagation across a rock joint with different orientations

Deep Underground Science and Engineering, EarlyView.
Joint orientation significantly affects P‐wave velocity, with the highest velocity at zero‐degree angles, decreasing to 30° as the angle increases. The velocity increases slightly from 30 to 45 degrees but sharply decreases from 45 to 90 degrees. Abstract Determination of the required parameters in different science contexts using the ultrasonic wave ...
Yaghoob Zarei, Mojtaba D. fallahi, Ali Uromeihy, Mohammad R. Nikoodel, Mohammad Fathollahy   +4 more
wiley   +1 more source

Concentration of K-feldspar from a pegmatitic feldspar ore by flotation

International Journal of Mineral Processing, 2006
Abstract Abundant reserves of Na-feldspar (albite) and K-feldspar (orthoclase or microcline) are found in granites, syenite, tracite and pegmatites. As both feldspar minerals have similar chemical structure and physicochemical properties, their separation is challenging. Flotation is known to be the only technique to enable their separation.
Karagüzel, Cengiz, Gülgönül, İlhan, Demir, Cengiz, Çınar, Mehmet Ulaş, Çelik, Mehmet S.   +4 more
openaire   +5 more sources

Hydrogen in Nominally Anhydrous Crustal Minerals [PDF]

, 2003
Systematic infrared and nuclear magnetic resonance investigations of common crustal minerals were undertaken to better understand the geologic significance of minor components of structural hydrous species within these nominally anhydrous minerals ...
Johnson, Elizabeth Ann
core   +1 more source

Fracture evolution of a thick soft protection layer and the water inrush mechanism in overburden under longwall mining

Deep Underground Science and Engineering, EarlyView.
Through shear–tensile creep tests and viscoelastic modeling, the fracture evolution of thick soft protective layers is clarified. Results show thickness‐dependent rheological failure modes that govern four types of roof water inrush, providing a mechanism‐based framework for hazard prediction and control. Abstract In the Jurassic coal‐bearing strata of
Mengnan Liu, Wei Qiao, Xianggang Cheng, Xiangsheng Meng, Peichao Feng   +4 more
wiley   +1 more source

Uso de diopsídio em massas cerâmicas para grés sanitários

Cerâmica
Resumo Atualmente, há uma severa escassez de jazimentos de feldspato de boa qualidade. Por outro lado, o diopsídio vem se mostrando um fundente alternativo para a indústria cerâmica, mas ainda pouco estudado.
R. H. L. Silva, G. A. Neves, H. C. Ferreira, L. N. L. Santana, A. C. V. Nóbrega, R. R. Menezes   +5 more
doaj   +1 more source

The role of heterotrophic bacteria in feldspar dissolution - an experimental approach

, 2003
\This paper presents the results of a laboratory study on the influence of heterotrophic bacteria on dissolution of a silicate mineral (K-feldspar) under a variety of growth conditions.
McLean, J., Gaze, W., Hutchens, E., Valsami-Jones, E., McEldowney, S.   +4 more
core   +1 more source

Anisotropy of magnetic susceptibility in alkali feldspar and plagioclase [PDF]

, 2016
Feldspars are the most abundant rock-forming minerals in the Earth’s crust, but their magnetic properties have not been rigorously studied. This work focuses on the intrinsic magnetic anisotropy of 31 feldspar samples with various chemical compositions ...
Angel, R. J., Pettke, Thomas, Hirt, A. M., Biedermann, Andrea R.   +3 more
core   +2 more sources