Thermal Desorption
Mostrando 13-24 de 51 artigos, teses e dissertações.
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13. Screening of By-Products of Esfenvalerate in Aqueous Medium Using SBSE Probe Desorption GC-IT-MS Technique
The pyrethroids, their metabolites and by-products have been recognized as toxic to environment and human health. Despite several studies about esfenvalerate toxicity and its detection in water and sediments, information about its degradation products is still scanty. In this work, esfenvalerate degradation products were obtained by chemical oxidation with h
J. Braz. Chem. Soc.. Publicado em: 2015-09
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14. MCM-41 for Meloxicam Dissolution Improvement:
in vitro Release and in vivo Bioavailability StudiesIn this study, MCM-41 was prepared as a carrier for poorly water soluble drugs. Meloxicam (MLX) was selected as model compound. Textural and chemical characterizations were carried out by thermal gravimetric analysis (TGA), scanning electron microscope (SEM), nitrogen adsorption/desorption, X-ray diffraction (XRD) and Fourier transform infrared (FTIR). Th
J. Braz. Chem. Soc.. Publicado em: 2015-07
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15. TUNGSTOPHOSPHORIC ACID HETEROGENIZED ONTO NH4ZSM5 AS AN EFFICIENT AND RECYCLABLE CATALYST FOR THE PHOTOCATALYTIC DEGRADATION OF DYES
Materials based on tungstophosphoric acid (TPA) immobilized on NH4ZSM5 zeolite were prepared by wet impregnation of the zeolite matrix with TPA aqueous solutions. Their concentration was varied in order to obtain TPA contents of 5%, 10%, 20%, and 30% w/w in the solid. The materials were characterized by N2 adsorption-desorption isotherms, XRD, FT-IR, 31P MAS
Quím. Nova. Publicado em: 2015-05
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16. DESENVOLVIMENTO DE MATERIAIS HÍBRIDOS MICRO-MESOPOROSOS DO TIPO ZSM-12/MCM-41
Micro-mesoporous hybrid materials of ZSM-12/MCM-41 type with different micro- and mesoporosity contributions were prepared by a procedure that uses the desilication of the zeolite in an alkaline medium, followed by recrystallization onto the mesostructure, where the zeolite is used as the silica source in the formation of mesoporous phase. The materials were
Quím. Nova. Publicado em: 2015-03
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17. Immobilization of Beauveria bassiana Lipase on Silica Gel by Physical Adsorption
Extracellular lipase from Beauveria bassianastrain CG481 was immobilized by using thirteen different immobilization protocols. Silica gel was chosen as the most suitable adsorbent with 94.8% of activity yield. The adsorption on silica gel did not change the optimum pH (8.5) and temperature (45ºC) values of the free lipase (FL) for lipolytic activity, and it
Braz. arch. biol. technol.. Publicado em: 2014-12
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18. Synthesis of zinc aluminate (ZnAl2O4) spinel and its application as photocatalyst
ZnAl2O4 spinel was synthesized by co-precipitation using ammonia as precipitating agent, followed by thermal treatment at 750 ºC. The structural properties of particles were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), differential thermal analysis (DTA), and N2 adsorption/desorption isotherms (BET) techniques. The photocatalytic
Mat. Res.. Publicado em: 30/05/2014
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19. Synthesis and characterization of novel ZrO2-SiO2 mixed oxides
In this study the mixed oxides ZrO2-SiO2, were synthesized by the sol-gel method with a molar ratio of 95:5 (Si/metal) and characterized by X-ray diffraction, absorption-desorption of N2, Fourier transform infrared spectroscopy, thermal gravimetric analysis, temperature-programmed desorption of ammonia, and acidity test by titration. The synthesized material
Mat. Res.. Publicado em: 15/04/2014
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20. Hydrogen absorption study of ti-based alloys performed by melt-spinning
The hydrogen absorption and desorption of Ti53Zr27Ni20 icosahedral quasicrystal (ICQ) and Ti50Ni50 shape memory alloy (SMA) melt-spun ribbons was studied. Samples were exposed to hydrogen gas at 623 K and 4 MPa for 1000 minutes. The total capacity of hydrogen obtained for Ti53Zr27Ni20 and Ti50Ni50 was 3.2 and 2.4 wt. % respectively. The Thermal Desorption Sp
Mat. Res.. Publicado em: 02/04/2013
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21. Biossorventes â biomassa de aguapà e esferas de alginato/goma do cajueiro â para adsorÃÃo de azul de metileno. / BIOSORBENTS - WATER HYACINTH BIOMASS AND SPHERES ALGINATE / CASHEW GUM - FOR ADSORPTION OF METHYLENE BLUE
In this work was carried out an extensive investigation of the adsorption properties of synthetic dyes on different parts (rhizome, root, stolon and petiole) of Eichhornia crassipes (water hyacinth) and a comparison with the adsorption capacity of the biopolymer alginate beads doped with water hyacinth biomass. The biomasses and spheres were structurally cha
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/02/2012
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22. Emission of isoprene by eucalyptus and its influence in the formation of tropospheric ozone / Emissão de isopreno por plantações de eucalipto e sua influência na formação de ozônio troposférico
Este é o primeiro estudo de medida de compostos orgânicos voláteis leves (C$_2$-C$_6$) realizado em uma plantação comercial de eucalipto do Vale do Paraíba. As coletas foram efetuadas numa área pertencente à empresa Fibria, localizada na cidade de Caçapava. Com o objetivo principal de estudar a influência do isopreno na formação de ozônio tropos
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/10/2011
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23. Produção de monoéster via etanólise por hidrotalcitas termoativadas : síntese e caracterização
Among biofuels of the 1st generation, biodiesel stands out for its equivalent features to those of mineral diesel, however less polluting. It can be obtained by transesterification of triglyceride fats or vegetable oils by (m)ethanolysis. Aiming at improving the chemical process, different types of catalysis have been studied: i) homogeneous (acid e.g. H2SO4
Publicado em: 2011
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24. Dynamic behavior of hydrogen desorption from pure iron and inconel 625 during elastic and plastic deformations
Dynamic behavior of hydrogen desorption from pure iron with a body-centered-cubic lattice and Inconel 625 with a face-centered-cubic lattice was examined during tensile deformation using a quadrupole mass spectrometer in a vacuum chamber integrated with a tensile testing machine. Hydrogen desorption from hydrogen-charged specimens was detected under various
Matéria (Rio de Janeiro). Publicado em: 2010