Results 71 to 80 of about 61,474 (312)

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

Calcite-forming Bacillus licheniformis Thriving on Underwater Speleothems of a Hydrothermal Cave

, 2018
The underwater environment of Grotta Giusti (Monsummano Terme, Italy) is a suggestive setting with different types of speleothems including “leafy” and “cauliflower” concretions along the walls and roof, and conical pseudo-stalagmites on the floor.
Alessandro Buccolieri (5220857), Daniela Manno (448227), Luciano Tanini (5444210), Pietro Alifano (70214), Salvatore Maurizio Tredici (587992), Matteo Calcagnile (4902010)   +5 more
core   +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

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

Organic chemical signatures of New Zealand carbonate concretions and calcite fracture fills as potential fluid migration indicators

, 2006
Macroscopic calcite crystals are common in sedimenta¬ry strata, occurring both as tectonic veins and also filling one or more generations of septarian rupture or later brittle fractures in calcareous concretions.
Nelson, Campbell S., Pearson, Michael J.
core  

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

Electrochemical and biomimetic deposition of calcium phosphates on titanium alloys

Физико-химические аспекты изучения кластеров, наноструктур и наноматериалов
The presence of impurities of other metals in titanium alloys affects the composition of the oxide film after heat treatment: in addition to rutile, the VT 00 alloy contains Ti6O oxide, which in the VT 1-0 and VT 6 alloys is transformed into Ti3O oxide ...
A.E. Doroshenko, V.K. Krut’ko, O.N. Musskaya, A.I. Kulak   +3 more
doaj   +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

Investigation of the interaction of water with the calcite {1014} surface using ab-initio simulation

, 2009
Density functional theory calculations were employed to explore the interaction between water and the {1014} surface of calcite. In addition a defective {1014} surface and stepped surfaces in contact with water were investigated.
Lardge, J.S.
core  

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