Supersaturation
Mostrando 1-12 de 42 artigos, teses e dissertações.
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1. SOLUBILITY OF A NEW ANTIRETROVIRAL DRUG (CRS 74) IN AQUEOUS ETHANOL MIXTURES
Abstract This study concerns a new antiretroviral drug named CRS 74, which has a limited bioavailability because of its low aqueous solubility and dissolution rate. To improve these properties, CRS 74 can be recrystallized by using Liquid Anti-Solvent (LAS) crystallization. Ethanol is chosen as the solvent under study for the molecule and water as the anti-s
Braz. J. Chem. Eng.. Publicado em: 2016-12
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2. A FORMAÇÃO DA CAMADA PROTETORA DE FeCO3 E O CONTROLE DA CORROSÃO POR CO2 EM CONDIÇOES DE FLUXO TURBULENTO
The formation of a protective layer of iron carbonate (FeCO3) can reduce the rates of corrosion and prolong the useful life of carbon steel. However, turbulent flow conditions in this layer can easily be damaged and thus compromise the protection of the steel. In this work, will be presented a methodology based on the chemical aspects of the mechanism of for
Quím. Nova. Publicado em: 2016-11
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3. EVALUATION OF SODIUM CHLORIDE CRYSTALLIZATION IN MEMBRANE DISTILLATION CRYSTALLIZATION APPLIED TO WATER DESALINATION
Abstract Crystallization in a Direct Contact Membrane Distillation (DCMD) process was studied both theoretically and experimentally. A mathematical model was proposed in order to predict the transmembrane flux in DCMD. The model fitted well experimental data for the system NaCl-H2O from undersaturated to supersaturated conditions in a specially designed crys
Braz. J. Chem. Eng.. Publicado em: 2016-09
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4. Antilithiatic Activity of phlorotannin rich extract of
Sarghassum Wightii on Calcium Oxalate Urolithiais –In Vitro andIn Vivo EvaluationABSTRACT Purpose: Urolithiasis is a common urological disorder responsible for serious human affliction and cost to the society with a high recurrence rate. The aim of the present study was to systematically evaluate the phlorotannin rich extract of
Sargassum wightii using suitable in vitro and in vivo modInt. braz j urol.. Publicado em: 2015-06
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5. Proposta e comparação de um modelo fenomenológico com base em alto transporte de massa e supersaturação para torre de resfriamento de água. / Presentation and comparison of a model based in high mass transfer and supersaturation in a cooling water tower.
Cooling towers are equipment widely used in industrial plants, where these operate under severe conditions such as cooling water inlet temperatures above 50oC. Under this condition, there are high evaporation of water and high mass transfer, generally not considered in performance analysis of a cooling tower. This work presents and analyzes the differences b
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/12/2011
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6. Aerossóis Atmosféricos: Medidas de Concentração sobre o Estado do Ceará. / Atmospheric Aerosols: Measurements of Concentration on the state of Ceara.
This work is a dissertation that aims to get standards in scientific measurements of the concentration of aerosols in the atmosphere over the State of Ceará and estimate empirical relationships between cloud condensation nuclei and nuclei of condensation on the basis of a set of supersaturation and the altitude. Data were used: the concentration of aerosols
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/03/2011
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7. Sistemas de análises químicas em fluxo explorando mecanismos de re-alimentação, calibração multivariada e outras abordagens para melhoria em desempenho / Flow systems exploiting feed-back mechanisms, multivariate calibration and other strategies for improving the analytical performance
Studies focusing on performance of intelligent analytical flow systems, association with multivariate calibration or use of nanocrystals as sensitizers were carried out. Moreover, improvements related to modifications in flow pattern were evaluated with emphasis to in-line dialysis. To this end, a strategy for implementing simultaneous determinations of iron
Publicado em: 2010
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8. Cristalização de insulina suina com dioxido de carbono como agente acidificante / Crystallization of porcine insulin with carbon dioxide as acidifying agent
Crystallization is a separation and purification technique used in the production of chemical, pharmaceutical and food products. The majority of the solid products is obtained by crystallization/precipitation processes that probably are the second most important separation technology in terms of capacity, behind only distillation processes. Studies on the us
Publicado em: 2009
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9. Fluxos de óxido nitroso na interface ar-mar na Baía de Guanabara
In Surface water concentrations of N2O were measured at 37 stations in Guanabara Bay and fluxes estimated across the air-sea interface. Concentrations averaged 8.2 ± 2.2 nmol L-1 and 90% of the stations showed supersaturation averaging 33%. N2O fluxes were estimated using a two-film model which is given by the product of the concentration difference across
Química Nova. Publicado em: 2008
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10. Cristalização de ácido cítrico : otimização operacional
In this work the crystallization of citric acid using Tahiti lemon juice was studied. The experiments were carried out in a batch crystallizer, with agitation and temperature control. The influences of three variables according to a composite experimental design on the production of citric acid were analyzed: super saturation, crystal number (seeding) and sp
Publicado em: 2007
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11. Modeling and simulation of rapid expansion of supercritical solutions
Rapid expansion of supercritical solution (RESS) is a promising technique for microparticle production. The literature points out that the RESS technique can be applied to process a wide range of materials including ceramics, polymers, biopolymers, pharmaceutics, and organic compounds. In order to achieve an adequate understanding of the RESS process, it is
Brazilian Journal of Chemical Engineering. Publicado em: 2006-09
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12. Effect of biomass-burning emitted aerosols on cloud droplets formation and rainwater chemistry in the Amazon Basin / "Os efeitos de aerossóis emitidos por queimadas na formação de gotas de nuvens e na composição da precipitação na Amazônia"
The main objective of this study was to investigate the relationship between anthropogenic emissions in the Amazon basin and the indirect aerosol effect on climate. A detailed study of physical and chemical properties of natural and biomass burning aerosols was conducted, in order to understand how these completely different aerosols behave as Cloud Condensa
Publicado em: 2005