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Mostrando ítems 331-340 de 598
Hidróxido de calcio químicamente puro y su relación clínica con diferentes tipos de solventes
(Universidad de Guayaquil. Facultad Piloto de Odontología, 2014-07)
El hidróxido de calcio o cal hidratada (otros sinónimos: hidrato de cal, cal apagada, cal muerta, cal aérea apagada, cal de construcción, cal química, cal fina, cal de albañilería, flor de cal, cal Viena) con fórmula ...
Promoted ceria catalysts for alkyne semi-hydrogenation
(Elsevier, 2015-01)
CeO2 is a highly selective catalyst for the partial hydrogenation of alkynes. However, due to its limited H2 splitting ability, a high operating temperature is required for the reaction, hampering the practical exploitation ...
Effect of catalyst preparation on the yield of carbon nanotube growth
(Elsevier Science, 2009-10)
Multi-wall carbon nanotubes (MWCNTs) were synthesized by catalytic chemical vapor deposition (CVD) on catalytic iron nanoparticles dispersed in a silica matrix, prepared by sol gel method. In this contribution, variation ...
Effect of the fluorination of DLC film on the corrosion protection of aluminum alloy (AA 5052)
(Elsevier B.V. Sa, 2010-06-25)
It is presented a study conducted on the physical and electrochemical properties of fluorinated a-C:H films deposited onto a commercial aluminum alloy (AA 5052). The coatings were deposited from mixtures of 91% of acetylene ...
Nitrous oxide production and potential denitrification in soils from riparian buffer strips: Influence of earthworms and plant litter
(Elsevier B.V., 2011-01-01)
Vegetated riparian buffer strips have been established in Southern Quebec (Canada) in order to intercept nutrients such as nitrate (NO(3)(-)) and protect water quality near agricultural fields. Buffer strips may also favour ...
Procedimentos para a determinação de cádmio para análise de amostras sólidas por espectrometria de absorção atômica com chama (SSA-FAAS)
(Universidade Federal de Santa MariaBrasilQuímicaUFSMPrograma de Pós-Graduação em QuímicaCentro de Ciências Naturais e Exatas, 2004-02-12)
The purpose of this study was to develop a system for solid sampling
analysis by flame atomic absorption spectrometry (SSA-FAAS), which would allow
the use of higher sample mass when compared to other devices reported ...
Utilização do sinal de fundo e calibração multivariada como um procedimento para acessar a concentração total de concomitantes em espectrometria de absorção atômica com forno tubular na chama e aerossol térmico (TS-FF-AAS)
(Universidade Federal de São CarlosUFSCarPrograma de Pós-Graduação em Química - PPGQCâmpus São Carlos, 2009-02-19)
TS-FF-AAS employs a metal tube atomizer above an air/acetylene flame and in this case, the atoms residence time is longer than that observed in FAAS (Flame AAS). As a result, elevated background signals are obtained. For ...
Espectrometria de absorção atômica com tubo aquecido na chama e amostragem direta de sólidos para determinação de manganês e níquel em coque de petróleo
(Universidade Federal de Santa MariaBRQuímicaUFSMPrograma de Pós-Graduação em Química, 2009-07-28)
A solid sampling flame furnace atomic absorption spectrometry (SS-FF-AAS)
system was developed in this work for Mn and Ni determination in petroleum coke.
The proposed solid sampling system was made in quartz, with two ...
Cyclopalladated compounds as chemotherapeutic agents: Antitumor activity against a murine melanoma cell line
(Wiley-Blackwell, 2003-11-10)
Palladacycle compounds obtained from N, N-dimethyl- I phenethylamine (dmpa), phenyl-2-pyridinyl-acetylene and 1-phenyl-3-N, N-dimethylamine-propine, respectively, were complexed to 1, 2 ethanebis (diphenylphosphine) (dppe) ...