production de calcite

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Production of Calcite (Calcium Carbonate) Crystals by Soil ... - Nature
1973.12.21 CERTAIN bacteria form crystals from the solutes in their aqueous environment, and some authors have associated this activity with the extensive deposits
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Pelagic calcium carbonate production and shallow
2023.2.20 We show that pelagic CaCO 3 production is higher than the sinking flux of CaCO 3 at 150 and 200 m at ocean stations ALOHA and PAPA, implying that a large
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Production of Calcite (Calcium Carbonate) Crystals by Soil ...
McCallum and Guhathakurta 9 observed calcium carbonate deposition by marine bacteria isolated from Bahama Island sediments and when these were cultured in different media
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Formations of calcium carbonate minerals by bacteria and its
2016.3.1 Biomineralization is a naturally occurring process in living organisms. In this review, we discuss microbially induced calcium carbonate precipitation (MICP) in detail.
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Calcite - an overview ScienceDirect Topics
Calcite crystals act as sites of further secondary calcite precipitation when the hyphae decompose. Through these processes, fungal activity is important in lithification
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An Overview of Calcite Recovery by Flotation - Springer
2020.9.23 Calcite ores typically contain metal sulphide, silicate, or other calcium-containing impurity minerals, which can be removed by flotation. A tremendous amount
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Calcium carbonate dissolution patterns in the ocean - Nature
2021.5.10 In the open surface ocean, coccolithophores, foraminifera and pteropods are common planktonic groups producing calcium carbonate (CaCO 3) shells or skeletons.
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Calcite - an overview ScienceDirect Topics
Calcite, crystallizing in the rhombohedral crystal system is the thermodynamically stable phase of calcium carbonate. Aragonite, calcite's orthorhombic polymorph, is about 1.5
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Bacterial Carbonatogenesis and Applications to Preservation
The scientific background is first presented, as far as aerobiotic metabolic pathways, biological processes and solid products are concerned. The process which consists in
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Aragonite dissolution protects calcite at the seafloor Nature ...
2022.3.1 In the open ocean, calcium carbonates are mainly found in two mineral forms. Calcite, the least soluble, is widespread at the seafloor, while aragonite, the more soluble, is rarely preserved in ...
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Production of Calcite (Calcium Carbonate) Crystals by Soil ... - Nature
1973.12.21 McCallum and Guhathakurta9 observed calcium carbonate deposition by marine bacteria isolated from Bahama Island sediments, and when these were cultured in different media aragonite crystals formed ...
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Calcite - Université du Québec à Chicoutimi
2021.5.7 augmente les coûts de production. GCC : La sélection des technologies de broyage et de pulvérisation de la calcite nécessite des technologies d’avant-garde afin de produire une qualité élevée, à un meilleur coût et avec une meilleure efficacité énergétique. Chaux : La technique actuelle de production de
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Définition Profondeur de compensation des carbonates
2023.5.9 Souvent abrégée en CCD (de l’anglais Carbonate Compensation Depth), la profondeur de compensation des carbonates est un niveau, ou un seuil, sous lequel le carbonate de calcium (ou calcite ...
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Le potentiel du stockage géologique du CO 2 par
2024.6.17 L’efficacité de ces méthodes repose sur une soustraction durable du CO. 2. au cycle du carbone grâce à un stockage sûr et permanent. Une des méthodes les plus sûres sur le long terme est la minéralisation de ce CO. 2. sous forme de minéraux carbonatés, comme la calcite (CaCO.
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Diel cycles in calcite production and dissolution in a
2010.2.9 1 Comisión Nacional de Energía Atómica, Buenos Aires, 1429 ArgentinaSearch for more papers by this author. Arthur J. Stewart, ... Calcite production is understood largely as a longer—term phenomenon (e.g., seasonal whitings) that can occur in hardwater lakes, and is significant ecologically because it can slow the rate of
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Bio-béton : la construction écologique de demain
2023.8.1 Le bio-béton est un matériau de construction innovant produit à l’aide de bactéries. Ces micro-organismes sont capables de produire de la calcite, un minéral qui peut être utilisé pour fabriquer du béton. Le bio-béton a le potentiel d’être plus respectueux de l’environnement que le béton traditionnel, car sa production peut ...
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An Overview of Calcite Recovery by Flotation - Springer
2020.9.23 Calcite is a valuable industrial mineral used in the production of value-added products such as paper, polymers, steel, and paint. The calcite quality requirements for these industries are presented below. The Paper Industry. Precipitated or beneficiated calcium carbonate is widely used as a filler and coating material in the manufacture of
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Modification of calcite by hydration–dehydration method for ...
2010.8.1 The crystallinity of all the samples was probed by powder XRD. The diffraction pattern for commercially available CaO (CaO C) was also presented for comparison purposes. Fig. 1 A shows the XRD patterns for fresh calcite, CaO S, and CaO W.The parent material showed major diffraction peaks at 29.4°, 36.2°, and 47.5°, which
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Bio-cement production using microbially induced calcite
2021.7.20 The production of bio-concrete in large scale using MICP process could expect to contaminate 100 km 3 of air and 4.5 × 10 6 m 3 of drinking water. ... Calcite amount precipitated was highly decreased in enzymatic option at a temperature above 30 °C than the bacteria option
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Comment la production de calcite intracellulaire chez les algues de ...
2024.5.27 Figure 1 : A) Micrographe électronique à balayage de la coque de coccolithes qui entoure l'algue Emiliania huxleyi. B) Concept de l'expérience d'analyse pulse-chase à base de Sr. Les cellules ont été cultivées dans des conditions qui bloquent la formation de coccolithes et produisent des cellules exemptes de coccolithes (calcite).
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Calcite production by the calcifying green alga Phacotus
The pores in the shells showed two variations. Wider pore canals penetrated the whole shell wall, whereas small, elongated pores were located along the interspaces between calcite crystals with tabular habit. The approximate average dimensions of these calcite plates were 1.0×1.6×0.2 μm.
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Directing polymorph specific calcium carbonate formation with de
2023.12.14 a The presence of a template reduces the free energy barrier of nucleation and the critical radius of the nuclei.b Coordination of calcium (top) by carbonate ions within a unit cell of calcite ...
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Calcite - an overview ScienceDirect Topics
Microcrystalline calcite in Isla de Mona carbonates is nonluminescent. Bladed calcite cements are often found in the Lirio Limestone. Nonluminescent, bladed (96 μm) calcite cement is found lining interparticle and moldic porosity on coralgal packstones and grainstones of both forereef and reef-flat facies.
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Pelagic calcium carbonate production and shallow
2023.2.20 Our foraminiferal calcite production estimate at Station 5 is 9 mg m-2 day-1, ... Ziveri, P., de Bernardi, B., Baumann, K.-H., Stoll, H. M. Mortyn, P. G. Sinking of coccolith carbonate and ...
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R ., M.), J., - Nature
2023.11.17 Physiqu e de la Vie dans /es ux (Masson et Cie, Paris, 1891) . 3 ZoBell , C. E ., in High P ressure Effects ... Production of Calcite (Calcium Carbonate) Crystals by Soil Bacteria is a General ...
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Production of Calcite (Calcium Carbonate) Crystals by Soil ...
Production of Calcite (Calcium Carbonate) Crystals by Soil Bacteria is a General Phenomenon. CERTAIN bacteria form crystals from the solutes in their aqueous environment and some authors have associated this activity with the extensive deposits of CaCO 3 in such places as the Grand Bahama, in spite of the belief that physicochemical
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Microbially induced calcite precipitation for production of
2020.1.20 The production of bio-bricks was usually conducted under a fully saturated condition via either surface percolation [2] or submergence [18]. However, according to Cheng et al. [ 8 ], the adequate bonding of precipitated calcite crystals that contribute to strength development of MICP treated soils are strongly affected by the degree of
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BG - Individual and interacting effects of pCO2 and
Laboratoire d'Océanographie Chimique et Géochimie des Eaux, Université Libre de Bruxelles (ULB), Bruxelles, Belgium ... No interacting effects of pCO 2 and temperature were observed on calcite production, coccolith morphology or on coccosphere size. Finally, our results suggest that ocean acidification might have a larger adverse impact on ...
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Formations of calcium carbonate minerals by bacteria and its
2016.3.1 Microbially induced calcite precipitation (MICP) refers to the formation of calcium carbonate from a supersaturated solution due to the presence of their microbial cells and biochemical activities (Bosak 2011).During MICP, organisms are able to secrete one or more metabolic products (CO 3 2−) that react with ions (Ca 2+) in the environment
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Calcite : Propriétés, Vertus, Signification de la
Elle renforce et confirme la force d’esprit de son porteur. C’est une pierre à utiliser comme support de méditation. La calcite bleue apaise les tensions psychiques et émotionnelles, elle permet de relativiser et encourage la
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Value added industrial minerals production from calcite-rich ...
2019.1.1 As a result of this study, the wollastonite concentrate which contains 0.44% Fe 2 O 3 , 52.71% SiO 2 , 87.85% wollastonite with 0.60% loss on ignition (using 1500 g/t potassium oleate) was ...
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Cosmogenic Chlorine-36 Production in Calcite by Muons
1998.2.1 The 36 Cl yield from muon capture by Ca in pure calcite is 0.012 ± 0.002 atom per stopped negative muon. The surface production rate of 36 Cl by muon capture on Ca in calcite is, therefore, 2.1 ± 0.4 atom g −1 a −1 at sea level and high latitude, approximately 11% of the production rate by Ca spallation.
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Calcite Production by Bacillus amyloliquefaciens CMB01
2003.12.1 An investigation of the conditions for calcite production by an alkalophilic Bacillus amyloliquefaciens CMB01 strain was made. Optimal calcite precipitation occurred when the bacterium was ...
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Dolostone (Dolomite) : Propriétés, Formation, Occurrence,
2023.11.20 La dolomite est un minéral et un minéral formant des roches composé de carbonate de calcium et de magnésium (CaMg(CO3)2). Il porte le nom du minéralogiste français Déodat Gratet de Dolomieu, qui a décrit pour la première fois ses propriétés à la fin du XVIIIe siècle. La dolomite se trouve souvent dans les formations rocheuses
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Comment la production de calcite intracellulaire chez les algues de ...
2024.7.15 Figure 1 : A) Micrographe électronique à balayage de la coque de coccolithes qui entoure l'algue Emiliania huxleyi. B) Concept de l'expérience d'analyse pulse-chase à base de Sr. Les cellules ont été cultivées dans des conditions qui bloquent la formation de coccolithes et produisent des cellules exemptes de coccolithes (calcite).
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Calcite production by coccolithophores in the south east
Calcite production by coccolithophores in the south east Pacific Ocean. Abstract. BIOSOPE cruise covered an oceanographic transect through the centre of the South Pacific Gyre (SPG) from the Marquesas archipelago to the Peru-Chile upwelling (PCU). Water samples from 6 depths in the euphotic zone were collected at 20 stations.
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Hydration of cement pastes with calcium carbonate
2023.11.1 For calcite and aragonite production, 221 g of CaCl 2 and 276 g of K 2 CO 3 were solubilized in two separate two-liter beakers of deionized water. To synthesize calcite, the calcium solution was slowly added to the potassium solution, and it was aged and mixed well for 16 h at 600 RPM. ... K. De Weerdt, M. Ben Haha, G. Le Saout, K.O.
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Equatorial Pacific Calcite Preservation Cycles: Production or ...
Higher rates of calcite and organic carbon rain to the sediment in the equatorial region would have depressed the calcite lysocline and increased the calcite accumulation rate, as observed. A twofold increase in glacial production appears to be adequate to explain the observations, but a precise determination is prevented by uncertainties in ...
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Strain improvement of Sporosarcina pasteurii for enhanced
2009.5.2 Phenotypic mutants of Sporosarcina pasteurii (previously known as Bacillus pasteurii) (MTCC 1761) were developed by UV irradiation to test their ability to enhance urease activity and calcite production. Among the mutants, Bp M-3 was found to be more efficient compared to other mutants and wild-type strain. It produced the highest urease
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