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Letteratura scientifica selezionata sul tema "Silicates"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 9 giugno 2025

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Articoli di riviste sul tema "Silicates"

Wooden, Diane H. "Cometary Silicates: Interstellar and Nebular Materials." Highlights of Astronomy 13 (2005): 495–97. http://dx.doi.org/10.1017/s1539299600016403.

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AbstractEvidence for interstellar material in comets is deduced from IR spectra, in situ measurements of Comet Halley, and chondritic porous interplanetary dust particles (CP IDPs). IR spectra of comets reveal the spectrally active minerals: amorphous carbon, amorphous silicates, and (in some comets) crystalline silicates. Evidence suggests amorphous silicates are of interstellar origin while crystalline silicates are of nebular origin.10 μm spectra of comets and sub-micron amorphous silicate spherules in CP IDPs have shapes similar to absorption spectra through lines-of-sight in the ISM. Thermal emission models of cometary IR spectra require Fe-bearing amorphous silicates. Fe-bearing amorphous silicates may be Fe-bearing crystalline silicates formed in AGB outflows that are amorphized through He+ ion bombardment in supernova shocks in the ISM.Crystalline silicates in comets, as revealed by IR spectra, and their apparent absence in the ISM, argues for their nebular origin. The high temperatures (>1000 K) at which crystals form or are annealed occur in the inner nebula or in nebular shocks in the 5 – 10 AU region. Oxygen isotope studies of CP IDPs show only 1% by mass of the silicate crystals are of AGB origin. Together this suggests crystalline silicates in comets are probably primitive grains from the early solar nebula.

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Niciu, H., Dorel Radu, C. Onose, A. Ioncea, Daniela Niciu, H. Stroescu, and C. S. Onose. "The Permanently Bonded Glass Decor from Chemical Precursors." Advanced Materials Research 39-40 (April 2008): 579–82. http://dx.doi.org/10.4028/www.scientific.net/amr.39-40.579.

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Alkaline earth metal silicates as well as many polyvalent metals silicates can be obtained through aqueous solutions reactions between an alkaline silicate solution and the solutions of metal salts. The vitrifiation of the oxide compositions, established by the necessary molar ratios for the projected glass, is realised by calculating the concentration of chemical precursors, through their reaction directly on the substrate. The sodium silicate viscosity in aqueous solution and the viscosity of nitrogenated compounds or oxalates necessary in the silicates synthesis is compatible with the necessary viscosity for ink-jet cartridges. The necessary silicates forming reactions were studied directly on the deposition support, so that the functional characteristics of the multicompartment ink-jet cartridges were used. Compositions were realised, in which the colouring effect was obtained with ionic colorants. The vitrifiation and the quality of the obtained thin films were studied through Optical Microscopy and Scanning Electron Microscopy.

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Heckmann, W., F. Ramsteiner, and Ch Mehler. "Morphology of Poly Amide Nanocomposites Characterized by Transmission Electron Microscopy (TEM) and Electron Spectroscopic Imaging (ESI)." Microscopy and Microanalysis 7, S2 (August 2001): 502–3. http://dx.doi.org/10.1017/s1431927600028580.

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The introduction of organophilic layered silicates into a polyamide matrix significantly improves stiffness and strength [1,2]. Two methods are known to prepare such nanocomposites. For both methods cations such as sodium, potassium, magnesium or calcium, located in the interlayer galleries of the layered silicates must be exchanged by quaternary alkyl ammonium ions containing at least one alkyl chain and so rendering the originally hydrophilic into an organophilic silicate. in the insitu-method monomeric caprolactam is intercalated between the modified silicate interlayers and subsequently polycondensated to polyamide. By this method the silicates can be broken down into their nanoscale building blocks as can be shown by TEM and ESI (Fig. 1). Another more direct possibility to delaminate the silicates is melt mixing in an extruder. with both methods similar degrees of delamination can be achieved.This paper presents some of our morphological results on polyamide containing organically modified montmorillonite.

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Kemmitt, T., and NB Milestone. "The Ring Size Influence on 29Si N.M.R. Chemical Shifts of Some Spirocyclic Tetra- and Penta-coordinate Diolato Silicates." Australian Journal of Chemistry 48, no. 1 (1995): 93. http://dx.doi.org/10.1071/ch9950093.

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A series of tetracoordinate spirocyclic silicates has been prepared from the reaction of a range of diols with tetraethoxysilane, Si ( OEt )4. The silicates can be converted into anionic pentacoordinate silicates by reaction with KOBut/18-crown-6 in toluene. Alternatively, the pentacoordinate spirocycles can be prepared directly without prior preparation of a tetracoordinate spiro silicate. 29Si n.m.r. studies have demonstrated that the chemical shifts are sensitive to both coordination number and ring size. Ring contributions to the 29Si chemical shifts are apparent for the five- membered ring spiro silicates, those for the pentcoordinate species being less than those for the tetracoordinate species. Acyclic and six- membered ring spiro silicates are virtually indistinguishable by 29Si n.m.r. spectroscopy, which demonstrates that no ring contribution to the chemical shift is apparent for this ring size.

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Molster, F. J. "Astromineralogy: Crystalline silicates." Symposium - International Astronomical Union 209 (2003): 291–98. http://dx.doi.org/10.1017/s0074180900208796.

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Silicates are the most abundant dust component in our Universe. For a long time it was generally assumed that around evolved stars only amorphous silicates were present. The infrared space observatory (ISO; Kessler et al. 1996) discovered that the abundance of crystalline silicates can be quite significant. Thanks to ISO it is now for the first time possible to determine the exact chemical composition of the silicates, and in contrast to the amorphous silicates, the crystalline silicates turned out to be very Fe-poor (i.e. forsterite and enstatite). Careful investigations of the spectra of crystalline silicates in several conditions, both in laboratory and in space, have taken place. It was found that not only the abundance of the crystalline silicates is related to the spatial distribution of the circumstellar dust, but also the shape of the features differs between sources with and without a disk-like dust distribution. Because of the many spectral features of the crystalline silicates one can easily determine temperatures and mass ratios for enstatite and forsterite. But even single features contain interesting information. The position and FWHM of the 69.0 micron forsterite feature, might be used as a new diagnostic of characteristic temperatures of (crystalline) silicate dust, while the 33.6 micron forsterite feature bears evidence for its formation history.

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Lii, Kwang-Hwa. "High-T, High-P Hydrothermal Synthesis of Uranium Silicates and Germanates." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C759. http://dx.doi.org/10.1107/s2053273314092407.

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Most uranium minerals can be classified as oxidized species in which U is fully oxidized to U(VI), and reduced species, in which U occurs primarily as U(IV). Uranyl silicates are an important group of uranium(VI) minerals in the altered zones of many uranium deposits [1]. Uranyl silicates have also received attention because they form when spent nuclear fuel interacts with water containing silicon under oxidizing conditions. One naturally occurring uranium(IV) silicate exists, namely coffinite (USiO4), which is the most important ore mineral for uranium after uraninite. Numerous synthetic uranium(VI) silicates and germanates containing organic amines or alkali metals as countercations have also been reported [2]. In contrast to the uranium(VI) compounds, the chemistry of materials containing uranium(V) is considerably less developed owing to the tendency of U(V) to either oxidize to U(VI) or disproportionate to U(IV) and U(VI). We have synthesized a pentavalent-uranium silicate and a germanate by a high-temperature, high-pressure hydrothermal method in gold ampoules contained in a high-pressure reaction vessel at ca. 600 °C and 170 MPa [3a,b]. Following the synthesis of the U(V) compounds, a number of mixed-valence uranium silicates and germanates have been synthesized, for example, a mixed-valence uranium(IV,V) silicate, Cs2K(UO)2Si4O12 [3c], a uranium(IV,VI) germanate, Cs8U(UO2)3(Ge3O9)3·3H2O [3d], uranium(V,VI) silicates and germanates, A3(U2O4)Ge2O7 (A = Rb, Cs) and [Na9F2][(UO2)3(Si2O7)2] [3e,f], and a uranium(IV,V,VI) silicate, Na7UO2(UO)2(UO2)2Si4O16 [3g] in which three oxidation states of uranium co-exist in one compound. In addition, tetravalent-uranium compounds, Cs2USi6O15 and Cs4UGe8O20 [3h,i], were also synthesized. All members in the family of uranium silicates and germanates with the oxidation states of uranium from +4 to +6 have been observed. In this presentation the high-temperature, high-pressure hydrothermal synthesis, crystal structures, and XPS spectroscopy of these interesting compounds will be reported.

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Liang, Jian-Jie, Alexandra Navrotsky, Thomas Ludwig, Hans J. Seifert, and Fritz Aldinger. "Enthalpy of Formation of Rare-earth Silicates Y2SiO5 and Yb2SiO5 and N-containing Silicate Y10(SiO4)6N2." Journal of Materials Research 14, no. 4 (April 1999): 1181–85. http://dx.doi.org/10.1557/jmr.1999.0158.

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The enthalpies of formation of two rare-earth silicates (Y2SiO5 and Yb2SiO5) and a N-containing rare-earth silicate Y10(SiO4)6N2 have been determined using high-temperature drop solution calorimetry. Alkali borate (52 wt% LiBO2·48 wt% NaBO2) solvent was used at 800 °C, and oxygen gas was bubbled through the melt. The nitrogen-containing silicate was oxidized during dissolution. The standard enthalpies of formation are for Y2SiO5, Yb2SiO5, and Y10(SiO4)6N2, respectively, –22868.54 ± 5.34, –22774.75 ± 8.21, and –14145.20 ± 16.48 kJ/mol from elements, and –52.53 ± 4.83, –49.45 6 ± 8.35, and –94.53 ± 11.66 kJ/mol from oxides (Y2O3 or Yb2O3, SiO2) and nitride (Si3N4). The silicates and N-containing silicate are energetically stable with respect to binary oxides and Si3N4, but the N-containing silicate may be metastable with respect to assemblages containing Y2SiO5, Si3N4, and SiO2. A linear relationship was found between the enthalpy of formation of a series of M2SiO5 silicates from binary oxides and the ionic potential (z/r) of the metal cation.

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P. C. Bennett, J. R. Rogers, W. J. "Silicates, Silicate Weathering, and Microbial Ecology." Geomicrobiology Journal 18, no. 1 (January 2001): 3–19. http://dx.doi.org/10.1080/01490450151079734.

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Iliushchenko, V., L. Kalina, P. Hruby, V. Bilek Jr, J. Fladr, P. Bily, and J. Bojanovsky. "The treatment of cementitious surface by selected silicate sealers." Journal of Physics: Conference Series 2341, no. 1 (September 1, 2022): 012003. http://dx.doi.org/10.1088/1742-6596/2341/1/012003.

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Over the past decades, the efficiency of the silicate-based surface treatment agents, in other words, sealers, in concrete systems has been widely investigated. The surface treatment technology protects the cementitious systems against the penetration of undesirable substances. Nevertheless, understanding of the several aspects concerning silicate-based sealers is not entirely clear. This paper studies the action mechanism of selected silicates such as potassium, sodium, lithium water glasses, and colloidal silica. The effectiveness of used sealers in terms of water absorption reduction, the ability of silicates to heal pores, and the influence on the microstructure of the cement substrate were studied. Instrumental methods such as rheology, mercury intrusion porosimetry, or scanning electron microscopy were used to achieve satisfactory results. Nuances between the unique film-forming sealers were found. Colloidal silica showed a low sealing effect compared to alkali silicates.

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Jakobsen, U. H. "A hydrated barium silicate in unmetamorphosed sedimentary rocks of central North Greenland." Mineralogical Magazine 54, no. 374 (March 1990): 81–89. http://dx.doi.org/10.1180/minmag.1990.054.374.08.

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AbstractA new occurrence of barium silicates has been found in unmetamorphosed sedimentary rocks of central North Greenland. Two different barium minerals have been identified, the Ba-feldspar hyalophane, and an unknown and hitherto undescribed hydrated Ba-silicate with an anhydrous chemical composition identical to cymrite but with about 4 moles of water in the mineral structure. Both silicates are found in a black organic-rich chert sequence in close association with baryte. No replacement textures are observed between the three Ba-minerals.The hydrated Ba-silicate in the unmetamorphosed rock sequence of the Navarana Fjord area is considered to represent a member in a sequence of Ba-silicates from the unknown Ba-silicate with four H2O in the structure (BaAl2Si2O8·4H2O), through cymrite with one H2O (BaAl2Si2O2O8·H2O) to celsian with none (BaAl2Si2O8). This sequence might reflect the continuous release of water during prograde diagenesis and metamorphism. The association between chert and Ba minerals in the sedimentary rocks of the Navarana Fjord area is believed to reflect an addition of silica and barium by hydrothermal solutions.

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Più fonti

Tesi sul tema "Silicates"

Villanova, de Benavent Cristina. "Compositional and structural characterisation of Ni-phyllosilicates in hydrous silicate type Ni-laterite deposits." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/396616.

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Ni-bearing Mg-phyllosilicates (commonly known as garnierites) are significant ore minerals in many Ni-laterite deposits worldwide. However, the characterisation of these mineral phases is complex, as well as their classification and nomenclature, due to their fine-grained nature, low crystallinity and frequent occurrence as mixtures. The aim of this study is to shed some light to the nature of the Ni-bearing Mg-phyllosilicates occurring at the Falcondo Ni-laterite. In this deposit, these minerals are found within the saprolite horizon mainly as fracture-fillings, coatings on joints and as breccias. The Falcondo garnierites display easily distinguishable different shades of green and characteristic textures, which correspond to different mineral phases. Five garnierite types were defined by X-ray diffraction (XRD), optical and electron microscopy, and electron microprobe (EMP) analyses: I) Ni-Fe-bearing serpentine-like, II) Ni-(Al)-bearing serpentine-like with minor talc-like, III) Ni-rich mixture of serpentine- and talc-like, IV) talc-like and V) sepiolite-falcondoite. The characterisation was completed with differential thermal analysis and thermogravimetry (DTA-TG), transmission electron microscopy (TEM), Raman spectroscopy, microfocus X-ray absorption spectroscopy (i.tXAS) and dissolution experiments, in order to gain further insight on these mineral phases from different points of view. EMP oxide totals and DTA-TG indicate that talc-like contain higher H2O than talc sensu stricto (about 4.5% mass loss at 200°C, and up to 5% at 650°C), and therefore the names kerolite-pimelite [(Mg,Ni)3Si4010(OH)2• nH20] should be used instead of talc-willemseite [(Mg,1•103Si401o(OH)21. Compositional data showed continuous Mg-Ni solid solution along the joins lizardite-nepouite/chrysotile-pecoraite (serpentine-like), kerolite-pimelite (talc-like) and sepiolite-falcondoite. The phases with larger amounts of talc-like displayed the highest Ni contents (up to 2.2 apfu out of 3 octahedral atoms). In addition, EMP analyses of the mixed phases showed deviations from the stoichiometric Mg-Ni solid solutions of serpentine and talc. This is best explained by mixing at the nanoscale, which was confirmed by XRD and high resolution TEM imaging. Furthermore, a detailed textural study by means of EMP quantified X-ray element imaging was used to explain the relationships between textural position, sequence of crystallization and mineral composition of the studied Ni-phyllosilicates. These results indicate several stages of growth with variable Ni content, pointing to recurrent changes in the physical-chemical conditions during the precipitation of the different Ni-phyllosilicates. HRTEM and low magnification imaging enabled to measure the characteristic basal spacings of these phyllosilicates and to observe a wide variety of nanotextures, respectively: 15-sectored polygonal serpentine, chrysotile tubes, lizardite lamellae, kerolite-pimelite lamellae and sepiolite ribbons. In accordance with EMP results, chemical analyses by TEM showed that Ni is more concentrated in the kerolite-pimelite lamellae than in the serpentine particles. In addition, the HRTEM revealed that kerolite-pimelite lamellae replace the Ni-poor serpentine particles. These observations evidence the processes of progressive Ni-enrichment within some Ni-bearing Mg-phyllosilicates. Characteristic Raman bands were observed for serpentine-, talc- and sepiolite-like phases, and therefore this technique allowed discriminating the different garnierite types. The synchtrotron radiation-based µXAS analyses were conducted to investigate the speciation of Fe (by Fe K-edge X-ray absorption near edge structure, XANES) and the local environment of Ni (by Ni K-edge extended X-ray absorption fine structure, EXAFS). The XANES results indicate that Fe in the weathered saprolite and in the garnierites is mostly oxidised, whereas in the primary serpentine from the ultramafic protolith it is in the ferrous form. The EXAFS spectra indicate that Ni is homogeneously distributed in the unweathered rock, and is accumulated in discrete domains (clusters) in the weathered saprolite and in all the garnierite types. Finally, the dissolution experiments of a set of garnierites which cover a wide range of mineral compositions at acidic pH suggest that the dissolution rates are faster in serpentine- dominated garnierites than in talc (kerolite)-dominated garnierites or sepiolite-falcondoite, and that the dissolution is not congruent, being the serpentine component the first to dissolve in the garnierite mixtures of serpentine and talc (kerolite). In summary, the various analytical techniques applied to the garnierites of this study provide an accurate outlook of their complex mineralogy, structures, textures and chemistry at different scales that provides further details on the formation of these Ni-bearing Mg- phyllosilicates in a lateritic environment. Els fil- losilicats de níquel (comunament anomenats "garnierites") són importants menes en molts jaciments laterítics de Ni del món. La seva caracterització, classificació i nomenclatura és complexa, ja que normalment es troben en forma de mescles íntimes de diferents fil- losilicats de gra molt fi i baixa cristal• linitat. L'objectiu d' aquesta tesi és avançar en el coneixement de la mineralogia dels fil- losilicats de Ni del dipòsit de laterites niquelíferes de Falcondo, a la República Dominicana, per mitjà de l'ús d'un ampli espectre de tècniques analítiques: difracció de pols de raig X, anàlisi tèrmica diferencial i termogravimetria, microscòpia òptica, microscòpia electrònica de rastreig, microsonda electrònica, microscòpia electrònica de transmissió, espectroscòpia Raman, espectroscòpia d' absorció de raigs X (EXAFS i XANES, amb radiació sincrotró) i per mitjà d'experiments de dissolució. Les garnierites de Falcondo es localitzen a la part baixa de l'horitzó saprolftic en forma de rebliment de fractures i vetes, i ciments i clasts en bretxes. Els principals resultats indiquen que hi ha cinc tipus de garnierites, segons el seu color, la seva mineralogia i la química mineral. La majoria són barreges de serpentina i talc hidratat (kerolita-pimelita), tot i que també hi ha fases de la sèrie sepiolita-falcondoita. La fase que concentra més Ni és la kerolita-pimelita, mentre que a la serpentina el Ni és sistemàticament molt baix i a la sepiolita-falcondoita és molt variable. Les imatges d' alta resolució obtingudes amb microscopi electrònic de transmissió indiquen que els fil- losilicats que componen les garnierites formen una gran varietat de textures: serpentina poligonal, tubs de crisòtil, lamel• les de lizardita, lamel• les de talc hidratat i cintes de sepiolita. A més, s'ha observat que la kerolita-pimelita (rica en Ni) reemplaça sistemàticament la serpentina (pobra en Ni). L'espectroscòpia Raman permet distingir els cinc tipus descrits de garnierites i per tant, s'ofereix com una tècnica ràpida, senzilla i no destructiva per analitzar aquest tipus de minerals al camp. L' absorció de raigs X per mitjà de radiació sincrotró ha permès identificar que tot el Fe contingut en les garnierites i en les serpentines de la saprolita està en forma de Fe3+, i que tot el Ni es troba acumulat formant clusters, i no pas en forma de solució sòlida homogènia, a la capa octaèdrica. Finalment, els experiments de dissolució suggereixen que les velocitats de dissolució són més ràpides en les garnierites que contenen molta serpentina, i que la dissolució no és congruent, sent el Mg el primer element en ser posat en solució, seguit del Si i del Ni.

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Rogers, Jennifer Roberts. "Nutrient-driven colonization and weathering of silicates /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004368.

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Claireaux, Corinne. "Mobilité atomique dans les silicates vitreux et fondus." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066401/document.

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Cette thèse traite de la diffusion couplée dans un système verrier industriel contenant quatre oxydes (SiO2, Al2O3, CaO, Na2O). La gamme de températures considérée s’étend de la transition vitreuse (650°C) au liquidus (1200°C). Les premiers résultats concernent la nature macroscopique de la diffusion. La matrice des coefficients de diffusion permet de quantifier la mobilité des composants et met en évidence de nombreuses interactions entre eux. D’autres informations sont obtenues à l’échelle microscopique. Les équations d’échanges synthétisent les principaux chemins de diffusion suivis au sein du système sous la forme de réactions. L’ensemble des données de la littérature est traité et semble converger vers des chemins de diffusion préférentiels. Des hypothèses sur les mécanismes de la diffusion des espèces sont proposées. Les résultats obtenus à basse température permettent de discuter les liens entre propriétés de transport et diffusion. L’étude de la structure du matériau s’est appuyée sur la spectroscopie Raman. Les expériences de diffusion donnent accès à un grand nombre de compositions verrières, permettant ainsi de développer un outil statistique de traitement des spectres. Les composantes spectrales ainsi obtenues sont discutées à la lumière des nombreuses observations décrites dans la littérature. Cette démarche permet également d’interpréter les composantes au travers des corrélations entre leurs intensités relatives et la composition du matériau ainsi qu’en étudiant leur évolution le long des profils de diffusion. La possibilité de faire de la spectroscopie Raman une technique de quantification des espèces est discutée This manuscript deals with the coupled diffusion in an industrial glass system containing four oxides (SiO2, Al2O3, CaO, Na2O). The temperature range extends from the glass transition temperature (650°C) to the liquidus (1200°C). The first results concern the macroscopic nature of diffusion. The matrix containing the diffusion coefficients quantifies the mobility of the components and highlights many interactions between them. Other information can be obtained at the microscopic scale. The exchange equations summarize the main diffusion paths followed by the system in reactions form. All the data from the literature are processed and they seem to converge towards preferential diffusion paths. Hypothesis about the mechanisms of diffusion of the species are proposed. The results obtained at low temperatures open a discussion of the relationship between transport properties and diffusion. The study of the structure of the material was based on Raman spectroscopy. Diffusion experiments provide a large number of glass compositions, which allowed us to develop a statistical tool for handling spectra. The spectral components thus obtained are discussed in the light of the many observations described in the literature. This approach allowed us to interpret the components through correlations between their relative intensities and the composition of the material and by studying their evolution along the diffusion profiles. The possibility of a Raman spectroscopy technique for quantifying species is discussed

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Claireaux, Corinne. "Mobilité atomique dans les silicates vitreux et fondus." Electronic Thesis or Diss., Paris 6, 2014. http://www.theses.fr/2014PA066401.

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Azenha, Marcelo Rodrigues [UNESP]. "Reparação óssea em alvéolos de ratas ovarectomizadas após implante com biovidro: análise histomorfométrica e imunoistoquímica." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/123378.

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Made available in DSpace on 2015-05-14T16:53:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-09-09Bitstream added on 2015-05-14T16:58:45Z : No. of bitstreams: 1 000821898.pdf: 1301763 bytes, checksum: d28b4fd5d34abcdbe6e39a7e3297aee3 (MD5) Objetivos: Avaliar o processo de reparo alveolar em ratas ovarectomizadas após implante com Biosilicato cristalino. Materiais e Métodos: Sessenta ratas foram divididas em quatro grupos (n = 15) de acordo com o tratamento: Grupo 1- ratas submetidas à cirurgia sham com alvéolos preenchidos com coágulo; Grupo 2-ratas submetidas à cirurgia sham com alvéolos preenchidos com Biosilicato cristalino; Grupo 3-ratas ovarectomizadas com alvéolos preenchidos com coágulo; e Grupo 4- ratas ovarectomizadas com alvéolos preenchidos com Biosilicato cristalino. Após 7, 14 e 28 dias os animais foram sacrificados e análises histomorfométricas (histologia e histometria) e imunoistoquímicas (Osteopontina e Osteocalcina) foram realizadas. A comparação dos resultados foi realizada utilizando o programa estatístico Assistat 2013 para Windows através da Análise de Variância e teste de Mann-Whitney, com resultados significantes sendo encontrados quando p≤0.05. Resultados: No período de 7 dias, os Grupos 1 e 3 apresentaram resultados superiores e estatisticamente maiores do que os Grupos 2 e 4 (p<0.05) quanto à formação óssea. Após o período de 14 dias as diferenças estatísticas mantiveram-se, com os Grupos 1 e 3 apresentando diferença estatisticamente significante maiores aos Grupos 2 e 4 (p<0.05). Aos 28 dias, a diferença estatística significativa permaneceu entre os mesmo Grupos estudados, sendo que nos grupos implantados com o Biosilicato cerca de 60% do alvéolo já havia sido preenchido por osso novo. A imunoistoquímica revelou expressão das proteínas Osteocalcina e Osteopontina, principalmente nos animais submetidos à cirurgia de ovarectomia. Conclusões: Os Grupos 1 e 3 foram os que apresentaram os melhores resultados durante todo o estudo, com o Biosilicato cristalino apresentando resultado favorável na reparação... Objectives: To evaluate the process of alveolar repair in ovariectomized rats after implantation with Biosilicate. Materials and Methods: Sixty rats were divided into four groups (n = 15) according to treatment: Group 1 - rats underwent sham surgery with alveoli filled with blood clot; Group 2 - rats underwent sham surgery with alveoli filled with crystalline Biosilicate; Group 3 - ovariectomized rats with alveoli filled with blood clot; Group 4 - ovariectomized rats with alveoli filled with crystalline Biosilicate. After 7, 14 and 28 days the animals were sacrificed and histomorphometric analysis (histology and histometric) and immunohistochemical (Osteopontin and Osteocalcin) were measured . The comparison of the results was performed using the statistical program Assistat 2013 for Windows by Analysis of Variance and Mann-Whitney tests, with significant results being found when p ≤ 0:05 . Results: During the 7- day period, Groups 1 and 3 showed better and significantly higher results in bone formation than Groups 2 and 4 (p<0.05). After 14 days the statistical differences remained between Groups 1 and 3 and Groups 2 and 4 (p<0,05). At 28 days, the statically difference remained significant between the same Groups, while the groups implanted with Biosilicate presented about 60% of the socket filled by new bone. Immunohistochemistry revealed expression of proteins osteocalcin and osteopontin, especially in animals subjected to ovariectomy surgery. Conclusions: Groups 1 and 3 were those with the best results throughout the study, with the crystalline Biosilicate presenting favorable result in bone repair without bioglass resorption. The immunohistochemical analysis showed that animals subjected to ovariectomy had a higher signaling in Ostecalcina and Osteopontin proteins

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Azenha, Marcelo Rodrigues. "Reparação óssea em alvéolos de ratas ovarectomizadas após implante com biovidro : análise histomorfométrica e imunoistoquímica /." Araçatuba, 2013. http://hdl.handle.net/11449/123378.

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Orientador: Osvaldo Magro Filho Banca: Celso Kooji Sonoda Banca: Sonia Regina Panzarini Barioni Banca: Luiz Guilherme Brentegani Banca: Osny Ferreira Júnior Resumo: Objetivos: Avaliar o processo de reparo alveolar em ratas ovarectomizadas após implante com Biosilicato cristalino. Materiais e Métodos: Sessenta ratas foram divididas em quatro grupos (n = 15) de acordo com o tratamento: Grupo 1- ratas submetidas à cirurgia sham com alvéolos preenchidos com coágulo; Grupo 2-ratas submetidas à cirurgia sham com alvéolos preenchidos com Biosilicato cristalino; Grupo 3-ratas ovarectomizadas com alvéolos preenchidos com coágulo; e Grupo 4- ratas ovarectomizadas com alvéolos preenchidos com Biosilicato cristalino. Após 7, 14 e 28 dias os animais foram sacrificados e análises histomorfométricas (histologia e histometria) e imunoistoquímicas (Osteopontina e Osteocalcina) foram realizadas. A comparação dos resultados foi realizada utilizando o programa estatístico Assistat 2013 para Windows através da Análise de Variância e teste de Mann-Whitney, com resultados significantes sendo encontrados quando p≤0.05. Resultados: No período de 7 dias, os Grupos 1 e 3 apresentaram resultados superiores e estatisticamente maiores do que os Grupos 2 e 4 (p<0.05) quanto à formação óssea. Após o período de 14 dias as diferenças estatísticas mantiveram-se, com os Grupos 1 e 3 apresentando diferença estatisticamente significante maiores aos Grupos 2 e 4 (p<0.05). Aos 28 dias, a diferença estatística significativa permaneceu entre os mesmo Grupos estudados, sendo que nos grupos implantados com o Biosilicato cerca de 60% do alvéolo já havia sido preenchido por osso novo. A imunoistoquímica revelou expressão das proteínas Osteocalcina e Osteopontina, principalmente nos animais submetidos à cirurgia de ovarectomia. Conclusões: Os Grupos 1 e 3 foram os que apresentaram os melhores resultados durante todo o estudo, com o Biosilicato cristalino apresentando resultado favorável na reparação... Abstract: Objectives: To evaluate the process of alveolar repair in ovariectomized rats after implantation with Biosilicate. Materials and Methods: Sixty rats were divided into four groups (n = 15) according to treatment: Group 1 - rats underwent sham surgery with alveoli filled with blood clot; Group 2 - rats underwent sham surgery with alveoli filled with crystalline Biosilicate; Group 3 - ovariectomized rats with alveoli filled with blood clot; Group 4 - ovariectomized rats with alveoli filled with crystalline Biosilicate. After 7, 14 and 28 days the animals were sacrificed and histomorphometric analysis (histology and histometric) and immunohistochemical (Osteopontin and Osteocalcin) were measured . The comparison of the results was performed using the statistical program Assistat 2013 for Windows by Analysis of Variance and Mann-Whitney tests, with significant results being found when p ≤ 0:05 . Results: During the 7- day period, Groups 1 and 3 showed better and significantly higher results in bone formation than Groups 2 and 4 (p<0.05). After 14 days the statistical differences remained between Groups 1 and 3 and Groups 2 and 4 (p<0,05). At 28 days, the statically difference remained significant between the same Groups, while the groups implanted with Biosilicate presented about 60% of the socket filled by new bone. Immunohistochemistry revealed expression of proteins osteocalcin and osteopontin, especially in animals subjected to ovariectomy surgery. Conclusions: Groups 1 and 3 were those with the best results throughout the study, with the crystalline Biosilicate presenting favorable result in bone repair without bioglass resorption. The immunohistochemical analysis showed that animals subjected to ovariectomy had a higher signaling in Ostecalcina and Osteopontin proteins Doutor

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Boulliung, Julien. "Solubilité, spéciation et diffusion de l'azote dans les verres et silicates fondus." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0254.

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L'azote (N) fait parti des éléments volatils (comme l'hydrogène et le carbone) essentiels à la vie sur Terre. Le comportement de cet élément lors des processus géologiques à haute température comme par exemple durant les processus magmatiques reste aujourd'hui très parcellaire. Cette thèse est centrée sur la solubilité, la spéciation et la diffusion de N dans les verres et silicates fondus dans le but de mieux comprendre comment cet élément se comporte lors de ces processus. La solubilité de N dans les silicates fondus a été étudiée pour différentes compositions et pour une large gamme de fO₂ (IW –8 à IW +4.1) à 1425°C et 1 atm. Les résultats montrent un effet majeur de la fO₂ et du degré de polymérisation des silicates fondus sur la solubilité de N. Ces nouvelles données suggèrent qu'un océan magmatique mafique à ultra-mafique aurait pu incorporer autant voir plus de N que ce qui est présent dans la Terre silicatée actuelle, supposant qu'une partie de N se soit échappée vers l'atmosphère ou que celle-ci est stockée dans la Terre profonde (i.e., manteau profond, noyau). Pour l'étude de la diffusion de N dans les verres et liquides silicatés, un développement expérimental et analytique a été nécessaire. Le premier coefficient de diffusion de N (sous la forme N³⁻) dans les silicates fondus, à partir de diffusion uni-axiale, a été mis en évidence pour un liquide de type basalte à andésite (i.e., 4.2 × 10⁻⁸ cm².s⁻¹). Cette étude a aussi permis de mettre en évidence l'effet de la composition du liquide sur la vitesse de diffusion de N³⁻ dans les silicates fondus. Cette dépendance à la composition des silicates fondus est plus importante pour N³⁻ que pour l'argon (Ar). Cela implique que le rapport N/Ar peut alors être fractionné lors de processus magmatiques en conditions réductrices (e.g., durant l'océan magmatique terrestre) Nitrogen (N) belongs to the volatile elements (like hydrogen and carbon) that are essential for life on Earth. The behavior of N during high temperature geological processes, such as during magmatic processes, remains poorly understood. This study focuses on N solubility, speciation, and diffusion in silicate glasses and melts to better understand the N behavior during these processes. N solubility in silicate melts was studied for different melt compositions and for a wide range of fO₂ (IW –8 to IW +4.1) at 1425°C and 1 atm. The data obtained highlight the fundamental control of fO₂ and the degree of polymerization of the silicate melt on N solubility. These new data suggest that a mafic to ultra-mafic magma ocean could have incorporated a similar or higher amount of N compared to the actual bulk silicate Earth, suggesting that N may have been to the atmosphere and/or stored in Earth's deep interior (i.e., deep mantle, core). For the study of N diffusion in silicate glasses and melts, experimental and analytical developments were necessary. The first diffusion coefficient of N (as N³⁻) in silicate melts was determined from uni-axial diffusion experiments in a basaltic andesitic melt (4.2 × 10⁻⁸ cm².s⁻¹). The data highlight that N³⁻ diffusivity depends on melt composition. This dependence on the melt composition is more important than that of argon (Ar). Furthermore, N³⁻ diffusion is significantly slower than that of Ar in similar silicate melts, implying that N/Ar ratios can be fractionated during reducing magmatic processes (e.g., during Earth's magma ocean stage)

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Hazm, Jamal Eddine. "Silicates et aluminosilicates microporeux obtenus en milieu fluoré avec, comme structurants, le 1,4-diazabicyclo [2,2,2] octane (DABCO) ou le 1-azabicyclo [2,2,2] octane (quinuclidine)." Mulhouse, 1992. http://www.theses.fr/1992MULH0238.

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Ce travail s'inscrit dans le cadre de l'exploration d'une nouvelle voie de synthèse hydrothermale des zéolithes. L'ion mobilisateur hydroxyde habituellement utilisé est ici remplacé par l'ion fluorure, avec pour corollaire l'emploi de milieux de synthèse de pH typiquement compris entre environ 7 et 10. L'utilisation de 2 structurants organiques différents, le 1,4-diazabicyclo [2,2,2] octane (« DABCO » ou le 1-azabicyclo [2,2,2] octane (« quinuclidine ») - combiné à des rapports molaires Si/Al variables - a permis respectivement la préparation des zéolithes bêta et de type MTW d'une part, ainsi que de la zéolithe de type LEV et d'un clathrasil inédit appelé octadécasil d'autre part. Les domaines respectifs de synthèse de ces 4 phases sont précisés puis celles-ci sont caractérisées par diverses techniques telles que la diffraction des rayons X, la microscopie électronique, les analyses thermiques, la RMN du solide. . . D'après la RMN 13C RAM, la molécule occluse dans la charpente des zéolithes bêta et de type MTW est essentiellement le polyéthylènepiperazine issu de la polymérisation du « DABCO » ; la charpente de la zéolithe de type LEV contient aussi, dans certaines conditions de synthèse, des espèces organiques dérivées de la molécule de quinuclidine initialement présente. Par ailleurs, dans le cas de l'octadécasil l'ion fluorure joue en plus de son rôle habituel de mobilisateur, un véritable rôle de structurant dans la mesure ou cet ion F- est incorporé dans la charpente silicique à l'intérieur des doubles cycles à 4 tétraèdres ; ceci constitue une des originalités marquantes de ce produit

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Bartelmehs, Kurt Lane. "Modeling the properties of silicates." Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-05042006-164529/.

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McCollam, Bridget E. "Thermochemistry of a synthetic Na-Mg rich triple-chain silicate determination of thermodynamic variables and geological applications /." Diss., Online access via UMI:, 2007.

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Libri sul tema "Silicates"

Mysen, B. O. Structure and properties of silicate melts. Amsterdam: Elsevier, 1988.

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Babushkin, V. I., G. M. Matveyev, and O. P. Mchedlov-Petrossyan. Thermodynamics of Silicates. Edited by O. P. Mchedlov-Petrossyan. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-69320-5.

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M, Matveev G., and Mchedlov-Petrosi͡a︡n O. P, eds. Thermodynamics of silicates. Berlin: Springer-Verlag, 1985.

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Webb, Sharon L. Silicate melts: With 33 figures. Berlin: Springer, 1997.

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Tagiev, D. B. Kristallicheskie ali͡u︡mosilikaty v katalize. Baku: Ėlm, 1989.

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L, Perchuk L., Kushiro I. 1934-, and Baker Donald R. 1927-, eds. Physical chemistry of magmas. New York: Springer-Verlag, 1991.

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Liebau, Friedrich. Structural Chemistry of Silicates. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-50076-3.

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International Agency for Research on Cancer., ed. Silica and some silicates. Lyon, France: International Agency for Research on Cancer, 1987.

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Akaogi, Masaki. High-Pressure Silicates and Oxides. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6363-6.

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Mossotti, V. G. Short-range physicochemical structure of amorphous aluminosilicates. [Denver, Colo.?]: Dept. of the Interior, U.S. Geological Survey, 1987.

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Capitoli di libri sul tema "Silicates"

Okrusch, Martin, and Hartwig E. Frimmel. "Silicates." In Springer Textbooks in Earth Sciences, Geography and Environment, 157–239. Berlin, Heidelberg: Springer Berlin Heidelberg, 2020. http://dx.doi.org/10.1007/978-3-662-57316-7_11.

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Castroviejo, Ricardo. "Silicates." In A Practical Guide to Ore Microscopy—Volume 1, 819–44. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-12654-3_135.

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Edler, Karen J. "Mesoporous Silicates." In Porous Materials, 69–145. Chichester, UK: John Wiley & Sons, Ltd, 2010. http://dx.doi.org/10.1002/9780470711385.ch2.

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Falcone, J. S., and J. G. Blumberg. "Anthropogenic Silicates." In Detergents, 367–82. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-540-47108-0_14.

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Verma, Pramod K. "Non-silicates." In Optical Mineralogy, 337–60. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-40765-9_16.

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Liebau, Friedrich. "Nomenclature and Structural Formulae of Silicate Anions and Silicates." In Structural Chemistry of Silicates, 69–75. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-50076-3_5.

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Babushkin, V. I., G. M. Matveyev, and O. P. Mchedlov-Petrossyan. "The Basic Concepts and Laws of Thermodynamics." In Thermodynamics of Silicates, 1–54. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-69320-5_1.

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Babushkin, V. I., G. M. Matveyev, and O. P. Mchedlov-Petrossyan. "Pyrosilicate Reactions." In Thermodynamics of Silicates, 55–249. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-69320-5_2.

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Babushkin, V. I., G. M. Matveyev, and O. P. Mchedlov-Petrossyan. "Hydration Reactions." In Thermodynamics of Silicates, 251–335. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-69320-5_3.

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Babushkin, V. I., G. M. Matveyev, and O. P. Mchedlov-Petrossyan. "Corrosion Reactions." In Thermodynamics of Silicates, 337–53. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-69320-5_4.

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Atti di convegni sul tema "Silicates"

Katsanis, E. P., W. B. Esmonde, and R. W. Spencer. "Soluble Silicates as Corrosion Inhibitors in Water Systems." In CORROSION 1985, 1–15. NACE International, 1985. https://doi.org/10.5006/c1985-85369.

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Abstract Sodium silicates, used alone or in combination with other chemical inhibitors, are a safe and reliable means of protecting water pipes from corrosion. Silicates have been used successfully to inhibit corrosion in water systems in homes and large buildings and in municipal and industrial water distribution systems. The silicates protect pipes by creating a thin protective film on pipe surfaces. In some cases, the silicates have also displaced or removed rust accumulations. Silicate treatment has proven equally effective with ferrous metals, lead, copper and alloys including brass. They also protect aluminum and other soft metals and alloys. This paper discusses the chemistry, conditions for use, time and aging effects and recommended dosage treatments for sodium silicate as a corrosion inhibitor. Sodium silicate is one of three treatments recommended in a report on corrosion contracted by the US Environmental Protection Agency. Some writers recommend silicates over other inhibitors when economic, toxicity and environmental factors are taken into consideration. Sodium silicate is low in cost and does not contribute to algal growth or to the eutrophication of fresh waters.

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Hock, Vincent F., Sean W. Morefield, Donna C. Day, Charles A. Weiss, Philip G. Malone, and Cullen L. Hackler. "The Use of Vitreous Enamel Coatings to Improve Bonding and Reduce Corrosion in Concrete Reinforcing Steel." In CORROSION 2008, 1–9. NACE International, 2008. https://doi.org/10.5006/c2008-08220.

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Abstract A series of vitreous enamel coatings that contain hydraulically reactive calcium silicates have been developed to improve the performance and service life of steel used as reinforcement in concrete structures. The new series of enamel coatings combine a layer of alkaline-resistant basecoat glass enamel with an outer coating of glass enamel that incorporates dicalcium silicate and tricalcium silicate. The basecoat protects the steel while the calcium silicates in the outer layer hydrate when placed in fresh concrete and bond tightly to the surrounding concrete paste. The bond strength between the concrete and steel is increased two to three times that developed with uncoated steel. The enamel over the steel produces durable corrosion protection. The new coating can be of value in increasing the performance and the service life of defense-critical infrastructure.

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Montes, E., H. H. Kline, and R. E. Foscante. "Designing VOC Compliant Silicates." In CORROSION 1990, 1–13. NACE International, 1990. https://doi.org/10.5006/c1990-90477.

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Abstract Development of VOC compliant solvent-based inorganic zinc silicate coatings involves consideration of the chemical reactions which form the binder, the test method used to measure VOC, and the increased film thickness which occurs on application of higher solids materials. The influence on product design of environmental conditions occurring during application and cure are reviewed for both solvent and water-based inorganic zinc silicate coatings.

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Pedersen, Lars Thorslund, Claus Weinell, Pascal Verbiest, and Jeroen Van Den Bosch. "Advancements in High Performance Zinc Epoxy Coatings." In CORROSION 2009, 1–10. NACE International, 2009. https://doi.org/10.5006/c2009-09012.

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Abstract The present work investigates the use of alloyed zinc powders in zinc epoxy and zinc silicate coatings. It is found that small amounts bismuth have a dramatic effect on rust creep resistance while nickel and magnesium was not found to have any effect in the tested range. 0.5% bismuth in the zinc reduces rust creep by up to 80% after cyclic exposure according to ISO20340. With the alloyed zinc it is possible to formulate zinc epoxy coatings with rust creep below 1 mm in the test, thus achieving performance similar to what is know from zinc silicates.

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Semmler, J., and P. J. Leinonen. "Characterization and Dissolution Studies of Bruce Unit 3 Steam Generator Secondary Side Deposits." In CORROSION 1998, 1–13. NACE International, 1998. https://doi.org/10.5006/c1998-98324.

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Abstract The physical and chemical properties of secondary side steam generator deposits in the form of powder and flake obtained from Bruce Nuclear Generating Station A (BNGS A) Unit 3 were studied. The chemical phases present in both types of deposits, collected prior to the 1994 chemical cleaning during the pre-clean water lancing compaign, were magnetite (Fe3O4), metallic copper (Cu), hematite (Fe2O3) and cuprous oxide (Cu2O). The major difference between the chemical composition of the powder and the flake was the presence of zinc silicate (Zn2SiO4) and several unidentified silicate phases containing Ca, Al, Mn, and Mg in the flake. The flake deposit had high hardness values, high electrical resistivity, low porosity and a lower dissolution rate in the EPRI-SGOG (Electric Power Research Institute-Steam Generator Owner’s Group) chemical cleaning solvents compared to the powder deposit. Differences in the deposit properties after chemical cleaning of the Unit 3 steam generators and after laboratory cleaning were noted. The presence of silicates in the deposit inhibit magnetite dissolution.

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Morefield, Sean W., Charles A. Weiss, Philip G. Malone, and Mike Koenigstein. "Reactive Silicate Coatings for Protecting and Bonding Reinforcing Steel in Cement-Based Composites." In CORROSION 2009, 1–13. NACE International, 2009. https://doi.org/10.5006/c2009-09492.

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Abstract Engineered glass-ceramic coatings that contain hydraulically reactive calcium silicates have been shown to be remarkably effective in increasing the bond strength between reinforcing steel and the surrounding concrete or mortar. The coatings are a mixture of portland cement and alkaline-resistant basecoat glass enamel. X-ray diffraction patterns indicate that all of the major reactive compounds, such as dicalcium silicate and tricalcium silicate and the ferrites and even gypsum survived the firing of the frit-cement mixture onto steel. When exposed to water the cement grains in contact with water hydrated to form gel products similar to those produced in hydrating normal cement paste. The hydration of the layer of cement appears to remove the “wall effect” and the bond strength between the concrete and steel is increased up to four times that developed with uncoated steel. The enamel over the steel isolates the metal and produces durable corrosion protection. A SEM study of cracks purposely produced in the enamel indicates the embedded cement grains will hydrate when moisture contacts them and produce hydration products that can fill fractures and raise the pH at the steel surface.

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Amjad, Z., and R. W. Zuhl. "The Role of Water Chemistry on Preventing Silica Fouling in Industrial Water Systems." In CORROSION 2010, 1–14. NACE International, 2010. https://doi.org/10.5006/c2010-10048.

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Abstract Deposition of silica and silicate based foulants in industrial water systems (e.g., cooling, desalination, geothermal) and in reverse osmosis systems continues to be one of most difficult challenges for water technologists. The complexity of controlling silica stems from the limited solubility of both amorphous (polymerized) silica and metal silicates in the feed waters. Once formed, silica scale is extremely difficult to remove and often requires the use of mechanical and/or chemical methods; fluoride-based chemicals which present environmental and safety concerns. Therefore, industrial water systems using silica fouling prone feed waters typically employ conservative operating criteria; e.g., cooling systems limit cycles of concentration and desalination systems limit recovery. This paper and results presented herein: Compare the performance of polymeric additives as silica polymerization inhibitors.Show the impact of impurities (i.e., inorganic and organic coagulant/flocculant) on the performance of silica inhibitors.Illustrate the effect of water chemistry (type and concentration of cations) on the performance of silica inhibitors.Characterize the composition of silica precipitates formed during the experiments.

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Neufuss, K., J. Ilavsky, J. Dubsky, B. Kolman, and P. Chraska. "Plasma Spraying of Silicates II." In ITSC 1999, edited by E. Lugscheider and P. A. Kammer. Verlag für Schweißen und verwandte Verfahren DVS-Verlag GmbH, 1999. http://dx.doi.org/10.31399/asm.cp.itsc1999p0636.

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Abstract Silicates represent a broad group of industrially important ceramic materials. The only silicate that is widely used for plasma spraying is zirconium silicate. Other silicates are generally not used, although they can offer interesting application properties. This paper presents results with other silicates: synthetic wollastonite, stoichiometric mullite, cordierite, and steatite. The input materials were produced in selected sizes from ceramic in industrial quality and applied with the water-stabilized plasma spray system PAL160 to form free-standing panels. The morphology of the microstructure, the thermal expansion, the bulk and filling densities, the open and closed porosity, the phase, and the chemical changes were evaluated. Paper includes a German-language abstract.

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Chráska, P., K. Neufuss, B. Kolman, and J. Dubsky. "Plasma Spraying of Silicates." In ITSC 1997, edited by C. C. Berndt. ASM International, 1997. http://dx.doi.org/10.31399/asm.cp.itsc1997p0477.

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Abstract A search for cheap spraying materials offering interesting properties is conducted in connection with utilization of the high throughput water stabilized plasma. In this regard very promising materials are silicates. WSP PAL 160 was used for spraying garnets in their natural form and fused and crushed basalt. Chemical composition of both these materials is based generally on the same components but their contents are different. Paper reports on the spraying parameters used and then describes the structure and phase composition of deposits as well as their selected properties. Garnet of almandine type can be sprayed very well at a wide variety of parameters while pyrope type spraying is more difficult. Very interesting coatings were made of basalt.

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Ctibor, P., J. Sedláček, K. Neufuss, J. Dubský, and P. Chráska. "Study of Dielectric Properties of Plasma Sprayed Silicates at Low Voltage." In ITSC2002, edited by C. C. Berndt and E. Lugscheider. Verlag für Schweißen und verwandte Verfahren DVS-Verlag GmbH, 2002. http://dx.doi.org/10.31399/asm.cp.itsc2002p0617.

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Abstract This paper examines the dielectric properties of silicate coatings including mullite (3Al2O3-2SiO2), steatite (MgSiO3), spodumene (Li2O-Al2O3-4SiO2), and olivine with near-forsterite (Mg2SiO4) composition. The materials were sprayed using a water-stabilized plasma gun and the deposits were removed from the substrate, polished, and sputtered with aluminum on both sides. Electrical tests consisting of voltage, resistance, and capacitance measurements showed that the relative conductivity of plasma-sprayed silicates is stable between 200 Hz and 1 MHz, which is suitable for many insulation applications. Paper includes a German-language abstract.

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Rapporti di organizzazioni sul tema "Silicates"

Shen, Andy Anda. Analyzing Silicates in Los Alamos’s Water Supply. Office of Scientific and Technical Information (OSTI), July 2019. http://dx.doi.org/10.2172/1557154.

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Wereszczak, Andrew A., Kathryn J. Ham, Yogesh K. Vohra, Georgiy Tsoi, Brian A. Oistad, Brett S. Kuwik, Emily F. Steiner, Osama Jadaan, and Benjamin L. Hackett. High-Pressure Mechanical Response of Two Vitreous Silicates. Office of Scientific and Technical Information (OSTI), November 2018. http://dx.doi.org/10.2172/1482450.

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Michael G. Nelson. CARBON DIOXIDE SEQUESTRATION BY MECHANOCHEMICAL CARBONATION OF MINERAL SILICATES. Office of Scientific and Technical Information (OSTI), April 2004. http://dx.doi.org/10.2172/826304.

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Belt, R. F., and J. A. Catalano. Investigation of Single Crystal Silicates for Blue Tunable Lasers. Fort Belvoir, VA: Defense Technical Information Center, June 1986. http://dx.doi.org/10.21236/ada171823.

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OJI, LN. Conditions Conducive to Forming Crystalline Uranyl Silicates in SRS Evaporators. Office of Scientific and Technical Information (OSTI), April 2004. http://dx.doi.org/10.2172/823370.

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William B. White, Michael R. Silsbee, and B. Joe Kearns. REACTION MECHANISMS OF MAGNESIUM SILICATES WITH CARBON DIOXIDE IN MICROWAVE FIELDS. Office of Scientific and Technical Information (OSTI), February 2004. http://dx.doi.org/10.2172/826203.

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Fripiat, J. J. Aluminum coordination and active sites on aluminas, Y zeolites and pillared silicates. Office of Scientific and Technical Information (OSTI), January 1992. http://dx.doi.org/10.2172/6923291.

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Schneider, E. Applications of high resolution NMR to geochemistry: crystalline, glass, and molten silicates. Office of Scientific and Technical Information (OSTI), November 1985. http://dx.doi.org/10.2172/6246018.

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OJI, LAWRENCE. Conditions Conducive to Forming Crystalline Uranyl Silicates in High Caustic Nuclear Waste Evaporators. Office of Scientific and Technical Information (OSTI), November 2004. http://dx.doi.org/10.2172/835626.

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Fripiat, J. J. Aluminum coordination and active sites on aluminas, Y zeolites and pillared layered silicates. Office of Scientific and Technical Information (OSTI), January 1991. http://dx.doi.org/10.2172/5874814.

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