Results 71 to 80 of about 78,343 (295)

Morphological characteristic and causes of color for the crystals of calcite from Liboje

Geologija, 2014
The crystals of calcite from the quarry Liboje were investigated and compared with calcite crystals from other quarries in the surrounding area of Celje.
Maja Plaskan, Sabina Kramar, Miha Jeršek   +2 more
doaj   +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

Influence of Selected Saccharides on the Precipitation of Calcium-Vaterite Mixtures by the CO₂ Bubbling Method

Crystals, 2019
Calcium carbonate is a compound existing in living organisms and produced for many biomedical applications. In this work, calcium carbonate was synthesized by a CO2 bubbling method using ammonia as a CO2 absorption promotor.
Donata Konopacka-Łyskawa, Natalia Czaplicka, Barbara Kościelska, Marcin Łapiński, Jacek Gębicki   +4 more
doaj   +1 more source

Strength, stability, and microstructure of simulated calcite faults sheared under laboratory conditions spanning the brittle-plastic transition [PDF]

, 2015
Destructive earthquakes are commonplace in tectonically-active carbonate-bearing terrains, often leading to severe economic damage and major loss of life (e.g. the Apennines, Italy).
ISES: Frictional behaviour of calcite-rich fault rocks & implications for seismicity in carbonate terrains, Verberne, B.A., Experimental rock deformation   +2 more
core  

Geochemical and stable isotope patterns of calcite cementation in the Upper Cretaceous Chalk, Uk: Direct evidence from calcite-filled vugs in brachiopods [PDF]

Hu, X-F, Jeans, C.V. and Dickson, J.A.D. 2012. Geochemical and stable isotope patterns of calcite cementation in the Upper Cretaceous Chalk, UK: Direct evidence from calcite-filled vugs in brachiopods. Acta GeologicaPolonica, 62 (2), 143-172.
Dickson, Tony, Jeans, Christopher, Hu, Xiufang   +2 more
core   +1 more source

Evaluating the utility of B/Ca ratios in planktic foraminifera as a proxy for the carbonate system : a case study of Globigerinoides ruber [PDF]

, 2015
This research was funded by NERC, Grant Number: NE/D00876X/2.B/Ca ratios in foraminifera have attracted considerable scientific attention as a proxy for past ocean carbonate system.
Prentice, K.C., Wilson, P.A., Rae, J.W.B., Erez, J., Foster, G.L., Bostock, H.C., Henehan, M.J., Marshall, B.J.   +7 more
core   +1 more source

Advancing mine pillar design: Evaluating traditional methods and integrating AI for enhanced stability of pillars in the Great Dyke, Zimbabwe

Deep Underground Science and Engineering, EarlyView.
B1 is bord width 1, B2 is bord width 2, L is the pillar length, W is the pillar width, red color and letter A represent the pillars, and white color and number 1 represent excavated areas. Pstress is the average pillar stress; σv is the vertical component of the virgin stress, MPa; and e is the areal extraction ratio. e = B o B o + B P ${\rm{e}}=\frac{{
Tawanda Zvarivadza, Hendrik Grobler, Peter Apata Olubambi, Moshood Onifade, Manoj Khandelwal   +4 more
wiley   +1 more source

Effects of temperature, pressure, and hydration on the microstructural characteristics and mechanical properties of calcite

Frontiers in Chemistry
Geotechnical geological disasters occur frequently in China. Especially under complex environmental conditions, the failure mode of rock and the change mechanism of its mechanical properties are not clear.
Xiaoyi Zhou, Qiuqi Chen, Xin Tang, Xin Tang, Ruiyu He, Zhangping Yan, Junjie Xiong, Yuhang Zhou, Linyan Li   +8 more
doaj   +1 more source

Mechanistic insights across curing regimes for enzymatic and biopolymer‐optimized reinforcement in rock masses

Deep Underground Science and Engineering, EarlyView.
This study examines the effects of curing temperature on the mechanical behavior of underground rock masses treated with enzyme‐induced calcite precipitation (EICP) and an innovative biopolymer‐modified EICP (BP‐EICP). Abstract Biocementation is an innovative and sustainable technique for reinforcing weak and weathered rock masses in natural and ...
Mary C. Ngoma, Oladoyin Kolawole
wiley   +1 more source