Crystallization
Mostrando 1-12 de 942 artigos, teses e dissertações.
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1. Biphasic 0.8BaTiO3/0.2Ni(1-x)CoxFe2O4 nanopowders by in situ sol-gel synthesis
Abstract Nanopowders of the 0.8BaTiO3/0.2Ni(1-x)CoxFe2O4 (x=0, 0.25, 0.5, 0.75, and 1) were synthesized by the in situ sol-gel method using poly(acrylic acid) (PAA1800) as a chelating agent. The synthesis developed using PAA1800 ensured the simultaneous crystallization of two phases. The results provided a reliable method for producing biphasic nanopowders i
Cerâmica. Publicado em: 2022
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2. Simultaneous Quantification of Amorphous and Crystalline Valsartan in Tablets Using Raman Spectroscopy and Chemometrics Tools
Valsartan is an antihypertensive active pharmaceutical ingredient (API), it is used in the amorphous state in the commercial products. As amorphous materials are metastable, amorphous valsartan can crystallize to valsartan E, promoting changes in the dissolution and bioavailability of the drug. Tablets containing metastable forms of APIs need special conditi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Preparation of Silicon Oxycarbide (SiCO) Ceramics from Different Polymer Architectures and Assessment on the Performance as Electrodic Materials for Voltammetric Sensing of Antioxidant Phenolic Compounds
Silicon oxycarbide (SiCO) ceramics obtained from polymer pyrolysis and with varied carbon contents were prepared and evaluated as new electrodic materials for sensing of tert butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) antioxidants. Three polymers were synthesized varying molecular architecture and aromatic carbon groups, followed by pyrolysi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Study of Crystallization and Composition on Silicon Oxycarbide (SiOC) and Silicon Boron Oxycarbide (SiBOC) Ceramics Obtained from Alkoxysilanes Precursors
This work deals on the preparation of silicon oxycarbide (SiOC) and silicon boron oxycarbide (SiBOC) ceramics from pyrolysis involving alkoxysilanes with different organic groups. Boron content, organic substituent and annealing time were evaluated on crystallization and composition of resulting ceramics. B-free precursors composed of methyltriethoxysilane (
J. Braz. Chem. Soc.. Publicado em: 2021-06
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5. Unified comprehension of the kinetics of isothermal ceramic processes under field-free and resonant wave-field conditions
Abstract This paper proposes a unified comprehension of the isothermal ceramic process kinetics stemming from mesoscopic irreversible thermodynamics. Accordingly, a unified process kinetic equation (UPKE) is derived, which predicts that the global isothermal process rate of any ceramic process is, in general, nonlinearly related both to its activation energy
Cerâmica. Publicado em: 2021-03
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6. Comparative analysis of butter thermal behavior in combination with bovine tallow
Abstract Assessment of butter authenticity in combination with animal fat is a major challenge. Changing the butter composition can affect crystallization and polymorphism properties. The purpose of this study was to evaluate the thermal behavior of butter combined with (0-15% w/w) bovine tallow using Digital Calorimetric Scanning, and to determine fatty aci
Food Sci. Technol. Publicado em: 2020-12
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7. MÉTODO MANUAL PARA DEPOSIÇÃO DE TINTAS FOTOLUMINESCENTES BASEADAS EM LOFS MISTAS APLICADO A CODIFICAÇÃO DE DOCUMENTOS
In this work, the process of synthesis of Metal-Organic Frameworks containing lanthanide ions (LOFs), accelerated via a precipitating agent, capable of accelerating the process of nucleation of MOF crystals, in order to explore the optical properties of this precursor solution (SP_Gd/EU-MOF), as a quick-response photoluminescent material in the coding of off
Quím. Nova. Publicado em: 2020-12
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8. Fatty acid profile and physicochemical, optical and thermal characteristics of Campomanesia adamantium (Cambess.) O. Berg seed oil
Abstract The aim of this study was to characterize the oil obtained from seeds of Campomanesia adamantium by physicochemical quality parameters, oxidative stability, antioxidant activity, quality indexes, optical and thermal stability and its fatty acid profile. These seeds were a relevant source of oil (83 mg g-1) with high potential antioxidant activity (I
Food Sci. Technol. Publicado em: 2020-12
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9. Ediacaran emerald mineralization in Northeastern Brazil: the case of the Fazenda Bonfim Deposit
Abstract The Fazenda Bonfim emerald deposit lies within the Seridó Belt. It is a classic example of deposit formed through metasomatic interactions between Be-rich granite intrusions and Cr(± V)-rich mafic-ultramafic rocks. The setting of the emerald mineralization was built under strong strike-slip dynamics, which produced serpentinization and talcificati
Braz. J. Geol.. Publicado em: 13/01/2020
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10. Glass Formation of Null-Matrix Cu-Hf-(Zr, Ti) Alloys
An approach following the null-matrix, Ti/Zr ratio of 2.08, for neutron diffraction was used to calculate the glass formation in Cu-Ti-(Hf,Zr) alloys. The Cu55Zr14.6Ti30.4, Cu61.48Hf18.52Zr6.48Ti13.52, Cu58.1Hf16.9Zr8.1Ti16.9 and Cu52.46Hf14.2Zr10.8Ti22.54 compositions (at. %), were calculated and prepared by argon arc melting. Copper die suction casting was
Mat. Res.. Publicado em: 13/01/2020
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11. SUCROSE CRYSTALLIZATION: MODELING AND EVALUATION OF PRODUCTION RESPONSES TO TYPICAL PROCESS FLUCTUATIONS
Abstract This work describes a phenomenological model of the two-massecuite system for sucrose crystallization, developed using EMSO software. In most Brazilian sugarcane industries, sucrose crystallization is performed using this system. This process is considered to be a fundamental step in obtaining sugar of the desired quality and accounts for a substant
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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12. Glass-ceramic produced with recycled glass
ABSTRACT The objective of this work is the production and characterization of glass-ceramic with recycled glass powder and 4% (w/w) of cerium dioxide. Eleven groups were defined with conformation pressure of 11.6 and 25.8 MPa, and cerium dioxide addition. The sintering temperatures of 650, 675, 700 and 750 °C were used. The raw material was formed into a mo
Matéria (Rio J.). Publicado em: 25/11/2019