Gaseous Diffusion
Mostrando 1-12 de 25 artigos, teses e dissertações.
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1. Dynamics of gas bubble growth in oil-refrigerant mixtures under isothermal depressurization
This paper proposes a numerical model to predict the growth of gaseous refrigerant bubbles in oil-refrigerant mixtures with high contents of oil subjected to isothermal depressurization. The model considers an Elementary Cell (EC) in which a spherical bubble is surrounded by a concentric and spherical liquid layer containing a finite amount of dissolved liqu
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2012-06
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2. Set of miniaturized structure used for manipulation of mixture. / Conjunto de estruturas miniaturizadas para manipulação de misturas.
Nowadays, mainly due to products miniaturization, engineering faces new horizons, which can be easily exemplified by the enhancement on nanotechnology development. Furthermore, not only environmental contamination but also environmental monitoring must be addressed in order to produce a systemic knowledge. Therefore, the aim of this work was to determine how
Publicado em: 2010
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3. Employment of cathodes of diffusion of oxygen in eletrotrolise of brine to produce chlorine / Emprego de catodos de difusão de oxigenio na eletrolise da salmoura para a produção de cloro
This work is investigating the performance of electrodes modified with gaseous diffusion of particles of Cu, for reduction of oxygen in the production of chlorine during the electrolysis of brine. Initially, the reaction was studied on the anodic oxidation of chloride ion. Using a single cell compartment, with the type DSA anode with an area of 1.5 cm2 as wo
Publicado em: 2009
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4. Autoamostrador de baixo custo para análise por injeção em fluxo
This paper describes a homemade autosampler for flow injection analysis (FIA), constructed with two step motors from old floppy disk drives (5¼-inch). The autosampler was connected to a computer through the parallel port and the sampling process was controlled by software in Quick Basic. The performance of the system was assessed by the determination of amm
Química Nova. Publicado em: 2009
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5. Estudos da deposição de filmes de diamante CVD sobre carbeto de tungstênio, com interface controlada de boreto / Studies of the deposition of diamond CVD films on tungsten carbide, boride with interface control
The objective of this work was to obtain adherent diamond films on WC-Co substrate through the hot filament assisted CVD technique, using a boriding process to form an intermediate layer and avoid the diffusion of the cobalt to the substrate surface. The boriding process consists of a reactive thermo diffusion treatment, in which boron atoms are spread in th
Publicado em: 2009
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6. VOLTAMMETRIC DETERMINATION OF LOW MOLECULAR WEIGHT SULFUR COMPOUNDS IN ASPHALT SAMPLES / DETERMINAÇÃO VOLTAMÉTRICA DE COMPOSTOS DE ENXOFRE DE BAIXO PESO MOLECULAR EM AMOSTRAS DE ASFALTO.
O teor de compostos de enxofre em asfalto tem relação com parâmetros de qualidade como reatividade, corrosibilidade, toxicidade e potencial poluidor. Neste trabalho, um método para a determinação simultânea de compostos de enxofre inorgânico e orgânicos de baixo peso molecular foi desenvolvido. A separação dos analitos das amostras asfálticas foi
Publicado em: 2008
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7. Estudo da degradação de ranitidina via H IND. 2 O IND. 2 eletrogerado/fenton em um reator eletroquimico com eletrodos de difusão / Studyof the degradation eletrochemical of ranitidine it saw H IND. 2 O IND. 2 eletrogerado/fenton in an eletrochemical reactor with electrodes of gaseous diffusion
The study of the electrochemical degradation of the ranitidine, a drug used in the therapy of gastric ulcers was development in two steps. In the first step was studied the electrochemical behavior of the ranitidine on platinum (Pt) and glassy carbon (CV) electrodes, using cyclic voltammetry in aqueous (K2SO4 0.1 M) and non-aqueous (NaClO4 0.1 M in DMF) elec
Publicado em: 2007
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8. Eletrocatálise das reações de oxidação de hidrogênio e de redução de oxigênio
This work discusses the electrocatalytic processes taking place in the polymer electrolyte fuel cell electrodes, specifically the hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR), because these are clear examples of electrochemical reactions favored by the use of electrocatalysts. Since the gaseous reactants are very little soluble i
Química Nova. Publicado em: 2005-08
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9. Modelo computacional bidimensional para escoamentos gasosos com transferência de calor em um reator tipo CVD / Computational model 2D for gaseous flow with heat transfer for a reactor type CVD
In this work was made the elaboration of an prototype for the computational numerical simulation of the gaseous ow, with transfer heat, applied to the reactor type CVD, existing in the Laboratorio Associado de Sensores e Materiais (LAS) of the Instituto Nacional de Pesquisas Espaciais (INPE). Initially, we intention was to dene which the best type of mesh to
Publicado em: 2005
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10. Concepção e estudo de um biofiltro para tratamento de compostos orgânicos voláteis COVs
In the last decade, biological purification of gaseous waste has become an important alternative to many conventional methods of exhaust air treatment. More recently, biofiltration has proved to be an effective and inexpensive method for the treatment of air contaminated with volatile organic compounds (VOCs). A biofilter consists in a reactor packed with a
Publicado em: 2005
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11. Efectos de la exposición a vacío y aire de películas de SnO2 con distinto espesor
Gas sensors based in semiconductor oxides show a change in the resistance when they are exposed to certain gaseous atmospheres. In this paper, the influence on the sensor electrical resistance with the film thickness in vacuum and air are studied. The conduction process is analyzed considering the existence of Schottky potential barriers at the grain boundar
Materials Research. Publicado em: 2003-12
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12. Construção de um sistema para mapeamento resolvido no tempo da emissão de chamas explosivas : estudo de misturas de vapor e etanol e oxigenio
The objective of this work was mapping the luminescent species in explosion flames. A system was construct to attained these objective and it was composed by a metallic tube where explosions are produced and a detection system to analyze the light emission of the explosion flames, through a quartz window on the tube. The system allows to control the temperat
Publicado em: 1995