Gaseous Chromatography
Mostrando 13-24 de 43 artigos, teses e dissertações.
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13. Estudos de formação e remoção de subprodutos de desinfecção (SPDS) em aguas contendo acidos humicols quando sumetidas a dioxido de cloro / Studies of formation and remotion of disinfection by products (DBP), generated by the oxidation of solutions containing humic substances throught the use of chlorine dioxide
The objective of the present research was to analyze the formation of disinfection by products (DPB), generated by the oxidation of solutions containing humic substances with the addition of bromide ions through the use of chlorine dioxide, isolated or associated with free chlorine in different concentrations and reaction times. The technique of gaseous chro
Publicado em: 2007
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14. Café (Coffea arabica, L.) submetido a diferentes condições de torrefação: caracterização química e avaliação da atividade antioxidante e sensorial / Coffee (Coffea arabica, L.) submitted to different roasting conditions: chemical characterization and evaluation of sensorial and antioxidant activity
Evaluation of antioxidant activity of plant phenolic compounds has been studied as an alternative to the use of synthetic antioxidants, such as butil-hydroxy -toluene (BHT). In this paper we evaluated the in vitro antioxidant capacity of coffee extracts (ether, ethanol and aqueous) and fractions ( free, bound and unbound) roasted for different periods of tim
Publicado em: 2007
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15. Evaluation of effectiveness of the sanitization of a water purification system. Sterilization of medical devices, residual dissipation of ethylene oxide and the use of green fluorescent protein (GFP) as an indicator of process control / Avaliação de eficácia da sanitização de um sistema de purificação de água. Esterilização de artigos médicos, dissipação residual do óxido de etileno e uso da proteína verde fluorescente (GFP) como inidicador de controle do processo
The water exerts important paper in different phases of critical items manufacture in the health care units, pharmaceutical industries, hospitals and clinics, becoming necessary a rigorous control of the water purification systems, storage and distribution, in order to prevent biofilms formation and cross-contamination between devices and patients, who are s
Publicado em: 2007
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16. Effects of operating conditions on compositional characteristics and reaction kinetics of liquid derived by delayed coking of nigerian petroleum residue
The thermal upgrading of Nigerian petroleum residue was studied at relatively low pressure in a delayed coking reactor system. In this work, the intent was to investigate the effects of process variables such as reaction temperature (200(0)C to 600(0)C), reaction time (0 to 120min), additive concentration loading and additive-to-residue ratio on the amounts
Brazilian Journal of Chemical Engineering. Publicado em: 2006-09
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17. Mathematical modeling and experimental study of styrene - butadiene emulsion copolymerization. / Modelagem matemática e estudo experimental da copolimerização de estireno e butadieno em emulsão.
Neste trabalho, estudos da copolimerização em emulsão de estireno e butadieno foram realizados em duas etapas. A primeira etapa consistiu na obtenção de um modelo matemático que representasse os processos em batelada e em semicontínuo através das principais variáveis do processo. Na segunda etapa, o efeito de diversas variáveis importantes ao proce
Publicado em: 2006
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18. Trihalomethane formation and remotion in pre-oxidation water treatment processes using chlorine / Formação e remoção de trihalometanos em aguas de abastecimento tratadas, na pre-oxidação, com cloro livre
The present research evaluated, in laboratory scale, the formation of trihalomethanes (THM) produced in oxidation reactions, with free chlorine, of water samples with humic acids, in different concentrations and reaction time. This research also studied the presence of the bromide ion, to evaluate, qualitatively and quantitatively, the different species of T
Publicado em: 2005
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19. Oxidation-reduction catalysis with zeolitic metasilicates / Catalise de oxido-redução via metalossilicatos zeoliticos
About forty catalyst materials were prepared among MFI zeolitic chromiumsilicates type and silica grafted by zirconium oxides, and after serve as anchoring cromium species. These materials were named Cr-ZSM-5 and Cr-SSM and were characterized to drive at catalytic process to change carbon monoxide to carbon dioxide. The characterizations involved, Powder X-R
Publicado em: 2005
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20. Effect of drying air temperature on the yield of essential oil and content of 1,8-cineol presents in the leaves of Eucalyptus camaldulensis / Efeito da temperatura de secagem no rendimento do oleo essencial e teor de 1,8-cineol presente nas folhas de Eucalyptus camaldulensis
The drying of leaves of Eucalyptus camaldulensis, whose essential oil presents 1,8-cineol as main component, is the subject of this work. The 1,8-cineol, also known as cineol and eucaliptol, can be used, for example, in the treatment of respiratory diseases. The objective of this study is to analyze experimentally the influence of the drying air temperature
Publicado em: 2005
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21. GRAU DE SAPONIFICAÇÃO DE ÓLEOS VEGETAIS NA FLOTAÇÃO SELETIVA DE APATITA DE MINÉRIO CARBONATÍTICO
The fatty acids are the principal collectors used in the anionic flotation of apatite. Two samples denominated partially hydrogenated Hidrocol and without hydrogenation Hidrocol, a sample of refined babassu oil, besides a sample of oleic acid, were characterized chemically through wet methods, by gaseous chromatography and infrared spectrometry. The partiall
Publicado em: 2005
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22. Study abaout the determination of benzene and ammonia in air using quartz piezoeletric sensor. / Estudo sobre a determinação de benzeno e amônia no ar, utlizando sensor piezelétrico de quartzo
The objective of this work was to study, develop and evaluate coatings for detecting benzene and ammonia in atmospheric air, by using a piezoelectric quartz sensor. Nowadays, piezoelectric quartz sensors are very important in Analytical Chemistry due to their numerous aplications (in gaseous fase or in solution). This method is based on the fact that the qua
Publicado em: 2005
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23. Synthesis of carbon nanostructures by using thermal plasma torch
Some recent results concerning the synthesis of carbon nanostructures in a thermal plasma generating by a plasma torch are presented. Several tests were carried out in different operational conditions. The plasma was formed with argon and different gas mixtures of argon-acetylene or argon-methane to which some catalyst materials (ferrocene and cerium oxide)
Brazilian Journal of Physics. Publicado em: 2004-12
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24. USO DE ANÁLISE MULTIVARIADA PARA DETERMINAR A COMPOSIÇÃO DE GASOLINA A PARTIR DA ESPECTROSCOPIA FT-RAMAN E CROMATOGRAFIA GASOSA / USE OF MULTIVARIED ANALYSIS TO DETERMINE THE GASOLINE COMPOSITION FROM THE FT-RAMAN SPECTROSCOPY AND GASEOUS CHROMATOGRAPHY
The determination of the gasoline components, and the contribution of these in the quality and final performance, had in the past a great number of studies that can create routines for the monitoramento of this fuel. The objective of this work is to identify and to quantify the main groups of composites that compose the distributed commercial gasoline in par
Publicado em: 2004