Mixing J
Mostrando 1-12 de 188 artigos, teses e dissertações.
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1. Physical and mechanical properties of low, ultralow and no cement refractory castables containing MgO nanoparticles developed in situ by means of polymeric resins
Resumo A introdução de nanopartículas de MgO desenvolvidas in situ na matriz de concretos refratários de baixo teor de cimento, ultrabaixo e sem cimento foi feita por meio de uma resina polimérica aquosa de baixa viscosidade, produzida pelo método Pechini. A adição da resina líquida aos concretos desempenhou dois papéis: primeiro serviu como fornec
Cerâmica. Publicado em: 14/11/2019
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2. Fresh properties of HPSCC containing SRA and expansive admixtures
ABSTRACT Shrinkage-reducing admixture (SRA) and expansive admixture (EXA) were used in high performance self-compacting concrete (HPSCC) to mitigate autogenous shrinkage. In order to evaluate the fresh properties of concretes, the rheological parameters were determined in a ICAR rheometer at 10, 25, 40, 60 and 90 min. The flow behavior of the mixtures was de
Matéria (Rio J.). Publicado em: 18/10/2018
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3. Electrochemical Systems for Renewable Energy Conversion from Salinity and Proton Gradients
Ever-rising energy demand, fossil fuel dependence, and climate issues have harmful consequences to the society. Exploring clean and renewable energy to diversify the world energy matrix has become an urgent matter. Less explored or unexplored renewable energy sources like the salinity and proton gradient energy are an attractive alternative with great energy
J. Braz. Chem. Soc.. Publicado em: 2018-05
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4. Thermal Properties and Kinetics of Al/α-MnO2 Nanostructure Thermite
In this work, thermal properties and kinetics of Al-nanoparticles/α-MnO2 nanorods thermite were reported. The α-MnO2 nanorods were synthesized using a hydrothermal method and were characterized by X-ray powder diffraction (XRD) and X-ray photoelectron spectra (XPS), then combined with Al nanoparticles based on the ultrasonic mixing method to prepare the na
J. Braz. Chem. Soc.. Publicado em: 2018-02
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5. Natural membranes of Hevea brasiliensis latex as delivery system for Casearia sylvestris leaf components
ABSTRACT Natural latex from Hevea brasiliensis (Wild. ex A.Juss) Müll.Arg., Euphorbiaceae, showed angiogenic action and Casearia sylvestris Sw., Salicaceae, leaf derivatives presented anti-inflammatory and wound healing activities. Therefore, an association of these effects was interesting for wound healing applications. The aims of this study were the deve
Rev. bras. farmacogn.. Publicado em: 2018-01
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6. Evaluation of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental dental resin-based materials
ABSTRACT Objective To evaluate the influence of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental resin-based materials photoactivated using different light curing units (LCUs). Material and Methods Experimental resin-based materials with the same organic matrix (60:40 wt% BisGMA:TEGDMA) were mechanically blended using a
J. Appl. Oral Sci.. Publicado em: 2016-12
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7. CONSTITUINTES QUÍMICOS E ATIVIDADE ANTIOXIDANTE IN VIVO DE FLAVONOIDES ISOLADOS DE Clusia lanceolata (Clusiaceae)
The phytochemical investigation of Clusia lanceolata leaves yielded fourteen compounds including six flavones, vitexin, isovitexin, isovitexin-2"-O-α-L-rhamnopyranoside, vitexin-2"-O-α-L-rhamnopyranoside, orientin and isoorientin, two phaeophytins [132-hydroxy-(132-S-)-phaeophytin a and 132-hydroxy-(132-R)-phaeophytin a], two triterpenes, α- and β-amyrin
Quím. Nova. Publicado em: 2016-11
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8. DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
AbstractEnhanced heat transfer in tubes under laminar flow conditions can be found in coils or corrugated tubes or in the presence of high wall relative roughness, curves, pipe fittings or mechanical vibration. Modeling these cases can be complex because of the induced secondary flow. A modification of the Graetz problem for non-Newtonian power-law flow is p
Braz. J. Chem. Eng.. Publicado em: 2015-06
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9. Effect of internal recirculation velocity in an anaerobic sequencing batch reactor (ASBR)
This paper discusses the effect of different internal recirculation velocities on the mixture and shear stress on the flocs in an anaerobic sequencing batch reactor (ASBR). Thus, simulations are performed using a computational fluid dynamics (CFD) tool to evaluate this dependency. The analysis of velocities and turbulent kinetic energy indicates that the hig
Braz. J. Chem. Eng.. Publicado em: 2014-12
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10. Effect of process variables on the preparation of artificial bone cements
The present work concerns the preparation of bone cements based on poly(methyl methacrylate) (PMMA), used mainly for prosthesis fixation and cavity filling for correction of human bone failures. A typical bone cement recipe contains methyl methacrylate, which polymerizes in situ during cement application. An inherent problem of this reaction is the large amo
Braz. J. Chem. Eng.. Publicado em: 2013-12
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11. CONTRIBUIÇÃO AO ESTUDO DE CAMPO CRISTALINO E TRANSIÇÕES 4f-4f EM SISTEMAS CONTENDO LANTANÍDEOS. / CONTRIBUTION TO THE STUDY OF CRYSTAL AND FIELD 4F-4F TRANSITIONS IN SYSTEMS CONTAINING LANTHANIDES.
A theoretical study of the interactions between the 4f electrons in lanthanide ions (Ln3 +) with the chemical environment was made using crystal field theory. The main effects were studied: change in position of the berycentre of the energy levels of the free ion, maximum splitting of the J level and contribution to 5D0-7F0 transition of Eu3+ ion. Use of sec
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/09/2012
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12. Bending investigation on carbon fiber/epoxy composites nano-modified by graphene
An extreme conditions situation, e.g. pre-salt deep sea exploration, requires new materials with even better performance. Nanotechnology is the new paradigm that can lead to the development of these new super materials. The effect of graphene pileups dispersion into carbon fiber/epoxy composites was investigated experimentally. The dispersion process was bas
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012-09