Phosphate Glasses
Mostrando 13-20 de 20 artigos, teses e dissertações.
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13. Prototropic processes studies in vitreous systems / Estudos de processos prototrópicos em sistemas vítreos
H+ transfer processes in SiO2 glasses, from photoacids as piranine (POH), were assigned to the presence of residual water in the gel. In these experiments the effects due to the buffer basic species (HPO4=) were however not investigated. The understanding on how prototropic reactions are mediated in solid media and how the activity of Brönsted acid and base
Publicado em: 2006
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14. Estudo de vidros fosfatos dopados com terras raras para aplicação em fibras ópticas e guias de ondas planares / Estudo de vidros fosfatos dopados com terras raras para aplicação em fibras ópticas e guias de ondas planares
In this work, the thermal and optical properties is of the system P2O5 - ZnO - Al2O3 - AO - PbO - La2O3 (mol %) + XEr2O3 [A = Ba; Mg; X = 0; 1; 2; 3; 4; 5 (wt %)] was studied aiming at applications in optical fibres and planar waves-guides, as optical amplifiers. Such system is unknown and of low cost if compared with others, for example, those made with tel
Publicado em: 2006
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15. Properties and structural features of iron doped BABAL glasses
The chemical durability, density and structure of the BABAL glasses with batch compositions (100-x)(0.30BaO·0.50B2O3·0.20Al2O3)·xFe 2O3 (1 < x < 10 mol%), were investigated using Mössbauer spectroscopy, electron paramagnetic resonance (EPR), X-ray diffraction, Raman and differential thermal analysis (DTA). The chemical durability for the glass of composi
Materials Research. Publicado em: 2003-06
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16. Preparation and biocompatibility of poly (methyl methacrylate) reinforced with bioactive particles
Calcium phosphates and bioactive glasses have been used in many biomedical applications for more than 30 years due basically to their bioactive behavior. However, ceramics are too brittle for applications that require high levels of toughness and easy processability. In this work, a biphasic calcium phosphate (BCP) and a bioactive glass composition (BG) were
Materials Research. Publicado em: 2003-06
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17. Gelificação termorreversivel em soluções aquosas de polifosfato de aluminio
Admixture of aqueous sodium polyphosphate solutions and aluminum salts (nitrate, sulfate and chloride) lead to the formation of thermoreversible gels. Gels formed above roam temperature change back to clear solutions, upon cooling. For some compositions, gel formation happens at roam temperature. This behavior was observed in polymeric systems, but it has no
Publicado em: 1995
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18. Obtenção de novos materiais pelo processo sol-gel : oxidos e fosfatos de ferro
Thermal and hydrotermal transformations of non-crystalline iron (III) hydroxoacetate (HAF), hydroxophosphate (HPF) and metaphosphate (MPF) were followed using these methods: iron (II) and total-iron determinations; infrared spectrophotometry; surface area and density measurements; Mössbauer, (VIS-UV) photoacoustic and electron spin resonance spectroscopies;
Publicado em: 1990
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19. Structure and properties of strontium-doped phosphate-based glasses
Owing to similarity in both ionic size and polarity, strontium (Sr2+) is known to behave in a comparable way to calcium (Ca2+), and its role in bone metabolism has been well documented as both anti-resorptive and bone forming. In this study, novel quaternary strontium-doped phosphate-based glasses, containing 1, 3 and 5 mol% SrO, were synthesized and chara
The Royal Society.
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20. Conduction-band-edge ionization thresholds of DNA components in aqueous solution
Numerous investigations have focused on DNA damage induced by ionizing radiation; however, photoionization threshold energies of nucleic acid components in aqueous solution are not known. Herein, data from gas-phase photoelectron experiments have been combined with results from self-consistent field and post-self-consistent field molecular orbital calculatio
The National Academy of Sciences.