Polymorph
Mostrando 1-12 de 59 artigos, teses e dissertações.
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1. Síntese e caracterização das fases minerais C3S, C2S, C3A e C4AF para utilização em cimento tipo Portland
Resumo As principais fases contidas no cimento Portland são 3CaO.SiO2 (C3S), 2CaO.SiO2 (C2S), 3CaO.Al2O3 (C3A) e 4CaO.Al2O3.Fe2O3 (C4AF). No processo industrial estas apresentam incorporações de outros elementos que dependem das matérias-primas e dos combustíveis utilizados na queima. O uso das fases puras auxilia na compreensão dos fenômenos envolvid
Cerâmica. Publicado em: 2019-01
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2. Conducting Behavior of Crystalline α-PbO2 as Revealed by DFT Calculations
PbO2 is one material that has recently emerged as potential transparent conducting oxide for applications in the modern opto-electronic industry. In this work the electronic structure of the α-PbO2 polymorph has been investigated, aiming to contribute to the understanding of its high levels of conductivity. DFT calculations using B3LYP hybrid density functi
Mat. Res.. Publicado em: 18/12/2017
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3. Rietveld Method in the Analysis of Polymorphism in Mebendazole Tablets Acquired in Brazil’s Drugstores
Mebendazole (MBZ) is an anthelmintic medicine known to exhibit the polymorphs A, B and C, where polymorph C is the one indicated for tablets. Mebendazole commercial tablets (references, generics and similars) were analyzed in this work using X-ray powder diffraction data and the Rietveld method (RM) aiming at characterizing and quantifying crystal phases. Fo
J. Braz. Chem. Soc.. Publicado em: 2015-09
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4. Nacre Compared to Aragonite as a Bone Substitute: Evaluation of Bioactivity and Biocompatibility
Aragonite is a metastable polymorph of calcium carbonate found in mollusk’s shells, appearing in tiles and prismatic columns, cemented in a protein matrix - mainly proteins - that acts as a framework on which the aragonite is nucleated forming nacre, besides selecting the morphology of the nucleated cristaline phase. The presence of the mineralyzing organi
Mat. Res.. Publicado em: 2015-04
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5. Cristalização preferencial de polimorfo do ácido Lglutâmico : uma abordagem por controle ótimo / Preferential crystallization of L-glutamic acid polymorph : an optimal control approach
Crystal size distribution control is of great importance to high-end chemical industry, especially in applications to the production of pharmaceuticals and foods. In these industries, another crystal characteristic is equally important: polymorphism. Strict regulations often require that only an specific type of polymorph may be present in a determined produ
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/07/2012
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6. INFLUÊNCIA DA ARTRITE ENCEFALITE CAPRINA (CAE) NAS CARACTERÍSTICAS FÍSICO-QUÍMICA E MICROBIOLÓGICA DO LEITE E ANÁLISE HISTOLÓGICA DA GLÂNDULA MAMÁRIA / INFLUENCE caprine arthritis encephalitis (CAE) IN PHYSICAL-CHEMICAL AND MICROBIOLOGICAL ANALYSIS OF MILK AND histopathologic
The caprine arthritis encephalitis (CAE) is a disease of chronic and debilitating condition caused by a virus the family Retroviridae, subfamily lentivirus and Orthoretrovirinae gender. In transmission, the milk and colostrum from goats infected serving as an important means of virus carrier, but work on the changes in the milk of infected goats are scarce.
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/07/2011
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7. Os polimorfos de carbonato de cálcio: uma síntese fácil de aragonita
Aragonite is a metastable polymorph of calcium carbonate. The calcareous exoskeletons of some organisms like corals or molluscs consist essentially of aragonite. The questions of how, and why these organisms prefer the thermodynamically unstable aragonite for the construction of their hard shells are discussed. The importance of the biomineralization process
Química Nova. Publicado em: 2008
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8. Extração, estruturas e propriedades de alfa- e beta-quitina
The fact that alpha- and beta-chitin adopt different arrays in the solid state is explored to emphasize their different properties and distinct spectral characteristics and X ray diffraction patterns. The methods for their extraction from the biomass in view of the preservation of their native structures and aiming to fulfill the claims of purity and uniform
Química Nova. Publicado em: 2007-06
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9. Estudo termoanalítico e de compatibilidade fármaco-excipiente de rifampicina e alguns medicamentos utilizados na terapêutica da tuberculose / Thermoanalytical study and drug-excipient compatibility of rifampicin and some medicines utilized in tuberculosis terapeutics
This work was aimed at implementing the thermal analysis and other physico-chemical and analytical techniques in the development and quality control of drugs and medicines for the treatment of tuberculosis, especially rifampicin. The differential scanning calorimetry (DSC), thermogravimetry/derivative thermogravimetry(TG/DTG), elemental analysis, X-ray diffr
Publicado em: 2007
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10. Conformational polymorphism of modafinil investigated using DFT calculations and vibrational spectroscopy / Polimorfismo conformacional no modafinil investigado atravÃs de cÃlculos DFT e espectroscopia vibracional.
Polymorphism, defined as the ability of a molecule (or a set of molecules) to adopt several packing arrangements, became, in the last decades, a field of research on its own. Among other advantages of studying polymorphic systems, one can cite the study of the influence of molecular packing on solid-state properties, a better understanding of nucleation and
Publicado em: 2007
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11. Incorporação de enxofre no silicato dicálcico do clínquer de cimento Portland: influência na estabilidade de polimorfos e na reatividade hidráulica / Sulfur incorporation on dicalcium silicate of Portland cement clinker: influence on polymorphic stability and hydraulic reactivity
The present study regards the incorporation of sulfur in dicalcium silicate (Ca2SiO4), a crystalline phase that represents 20 to 40 wt. % of the common Portland cement clinker. In the cement industry this compound is known as C2S (2CaO.SiO2) or belite. It has five polymorphs, and the monoclinic high temperature ?-C2S has the highest reactivity with water. Th
Publicado em: 2007
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12. Termodecomposição, estudos de carbonização e silicificação da matéria orgânica e corpos silicosos em ecossistemas terrestres no Brasil e na Antártica / Thermodecomposition, organic matter carbonization silicification studies and silica bodies in terrestrial ecosystems in Brazil and Antarctica
Soil organic matter (SOM) is highly heterogeneous in composition, which consists of components as different from each other as labile carbohydrates and recalcitrant aliphatic compounds. Mean residence time (MRT) of the various compounds comprising soil organic matter may range from a few minutes to thousands of years. This wide range is partly due to the soi
Publicado em: 2007