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Showing 1 to 16 of 16 for “"Fluorapatite"”.
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Electron paramagnetic resonance spectroscopic study of two gadolinium centres at calcium sites in synthetic fluorapatite
Gd-doped fluorapatite, synthesized from CaF₂-rich melts, has been investigated as single crystals and powder samples by using X-band (9.5 GHz) and W-band (95 GHz) electron paramagnetic resonance (EPR) spectroscopy. Gd₂O₃ with natural abundances of isotopes and ¹⁵⁷Gd-enriched Gd₂O₃ were used in the …
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Halogen-element (F, Cl, and Br) behaviour in apatites, scapolite, and sodalite : an experimental investigation with field applications
… Twenty-nine partitioning experiments between fluorapatite (FAP) /chlorapatite (ClAP) and coexisting melts were conducted in the system of CaO-P2O5-CaF2-CaCl2–NaBr at 1120 degree C to 1400 degree C and atmospheric pressure. The partition coefficients (D) with errors of 1 sigma in parentheses …
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Production of phosphorus alloys through thermal reactions and electrochemical reduction of molten apatite
A process for extracting phosphorus from fluorapatite through high temperature electrochemical means. Theoretical modelling and calculations show that P-alloys can be manufactured directly from decomposed molten fluorapatite. Nickel-phosphide is chosen as an examplary alloy both for its incredible …
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Obtaining 1D dynamics in a quasi-1D NMR spin system
… coherences in a quasi-iD crystal lattice, Fluorapatite (FAp), through the use of NMR. In particular I focused on the system with chains aligned with the magnetic field axis, and with the so-called "magic angle" of 54.7°. In addition, I created a new method of rotation and long RF pulses for …
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The development and application of microanalytical (U-Th)/He thermochronology
… existing de facto (U-Th)/He age standard, the fluorapatite of Cerro de Mercado (Durango, Mexico), does not yield reproducible dates, an observation confirmed at several laboratories. A series of experiments combining analytical and numerical techniques suggests that variations in U and Th …
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ΘΕΡΜΙΚΗ ΣΥΜΠΕΡΙΦΟΡΑ ΤΟΥ ΣΥΣΤΗΜΑΤΟΣ CAHP04.2H20-CA(H2P04)2.H20-SI02 ΚΑΙ ΟΞΙΝΟΘΕΡΜΙΚΗ ΕΠΕΞΕΡΓΑΣΙΑ ΤΩΝ ΦΤΩΧΩΝ ΦΩΣΦΟΡΙΤΩΝ (ΗΠΕΙΡΟΥ)
… IS A POOR PHOSPHORITES WITH MAIN USEFUL ORE THE FLUORAPATITE AND MAIN IMPURITIES QUARTZ, WHICH CAN NOT BE BENEFICIATED SATISFACTORILY FOR FURTHER WET PROCESS TREATMENT. THE UTILIZATION OF THE PHOSPHATE ROCK FOR THE PRODUCTION OF POLYPHOSPHATE FERTILIZERS, BY THE ACID-THERMAL TREATMENT, AND THE …
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The sedimentology and palaeoecology of the Coralline Crag (Pliocene) of Suffolk
… techniques and found to be francolite (carbonate fluorapatite). The phosphorite is overlain by a bioturbated, bioclastic silty sand facies deposited in shallow marine conditions at an early stage during the transgression. This facies is succeeded laterally and is overstepped by a sandwave facies …
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The petrography and major element geochemistry of the phosphorite nodule deposits on the Agulhas Bank, South Africa
… mineral present is francolite, a carbonate fluorapatite, while optically this mineral has been identified as cellophane. An X-Ray diffraction peak-pair technique has indicated an average 5.5% CO₂ concentration in the apatite phase of the phosphorites. Studies on the major element …
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Effect of zinc substitution on the structure of calcium Fluoro-Alumino-Silicate glasses and glass-ceramics
… calcium base glass composition crystallized to Fluorapatite and mullite, zinc substitution led to the formation to a gahnite (ZnAl\(_2\)O\(_4\)) and calcium zinc phosphate (CaZn\(_2\)(PO\(_4\))\(_2\)) phases. ESEM and EDX analysis showed changes in the morphology of glass ceramics with zinc …
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Theory and Utility of the Three Isotope Fractionation Relationship
… for pairs of quartz, calcite, dolomite, fluorapatite, hematite, magnetite and liquid water. The results presented here compare well with previous studies on 18O/16O fractionation where data is available. Of the models given here, pairs of quartz, calcite, dolomite and fluorapatite with …
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Les iguanodons de Bernissart: leur évolution diagénétique et les processus de dégradation
… was replaced by well crystallized carbonated fluorapatite currently present in the Iguanodon bones. Whereas some minerals infiltrated in the bone during cavity filling by the sediment (“mainly” quartz, “argillaceous” phyllosilicates), others are authigenic and precipitated in the cavities …
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Probing structure-property relationships of calcium hydroxyapatite defluoridation to enhance performance
… Consistent with the fact that the a parameter of fluorapatite (FAP, Ca5(PO4)3X, where X=F) is significantly smaller than that of HAP, the a parameter of fluoridated HAP samples decreased with increased F- uptake, providing strong physical evidence of F- internalization. Time-resolved quantitative …
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Stratigraphy, genesis, and economic potential of the southern part of the Florida land-pebble phosphate field
… and the enrichment of the contained carbonate fluorapatite by replacement processes.</p> <p>Very gentle scarps, representing Pleistocene sea standstills, divide the land-pebble field into several physiographic subdivisions. The physiographic provinces of the land-pebble field and the origin of …
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Sedimentological study of the western zone of the Lady Annie phosphate deposit, Queensland, Australia
… almost entirely of finely crystalline carbonate fluorapatite. X-ray diffraction revealed that silica is the dominant gangue mineral in all phosphorites, clays are minor and micas and dolomite are very minor. Comparisons are made between the facies observed in the study area and similar facies …
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Sedimentological study of the western zone of the Lady Annie phosphate deposit, Queensland, Australia
… almost entirely of finely crystalline carbonate fluorapatite. X-ray diffraction revealed that silica is the dominant gangue mineral in all phosphorites, clays are minor and micas and dolomite are very minor. Comparisons are made between the facies observed in the study area and similar facies …
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Neue Untersuchungen zu Wachstum und Struktur von Fluorapatit-Gelatine-Nanokompositen
Die vorliegende Dissertation beschäftigt sich mit Wachstum und Aufbau von Fluorapatit-Gelatine-Nanokompositaggregaten. Diese Aggregate werden im sogenannten Doppeldiffusionsversuch biomimetisch erzeugt und ihre äußere Form bzw. Formentwicklung lässt sich anhand eines fraktalen Modells bis ins …