Encontrados 44 documentos, a visualizar página 1 de 5

Lab Classes in Chemistry Learning - An Artificial Intelligence View

The teaching methodology used in lab classes in Chemistry Learning was studied for a cohort of 702 students in the 10th grade of Portuguese Secondary Schools. The k-Means Clustering Method, with k values ranging between 2 (two) and 4 (four), was used in order to segment the data. Decision Trees were used for the development of explanatory models of the segmentation. The results obtained showed that the majority...

Electrocatalitic activity of platinum deposited on carbon functionalized with s...

Results are presented for Pt deposited on 4-aminobenzenesulphonic acid-functionalized carbon, Pt/C_ABSA. Vulcan XC-72R was functionalized in order to influence catalyst dispersion and decrease the resistance of three phase boundary, by introducing sulphonic groups and lessening the amount of Nafion® added to the catalyst layers. Electrochemical characterization of the supported catalyst was done in a 0.5 M H2SO...

Electrochemical behaviour of ionic liquid functionalized carbon supported Pt-Ru...

Ionic liquid (IL) functionalized carbon supported nanocatalysts, including platinum-ruthenium catalysts, have been under investigation to achieve better catalytic performance on polymer electrolyte membrane fuel cells. Ionic liquids have particular physical properties, which usually improve the stabillity and dispersion of metal nanosized particles, providing an increase of the electrochemical active surface ar...

Enhancing Pt electrocatalytic activity by surface functionalization of carbon s...

Preliminary results are presented for Pt deposited on 4-aminobenzenesulphonic acid-functionalized carbon, Pt/C_ABSA. Vulcan XC-72R was functionalized with the objective of influencing the dispersion of catalyst nanoparticles and to decrease the resistance of three phase boundaries, by introducing sulphonic groups. Electrochemical characterization of the supported catalyst was done in a 0.5 M sulphuric acid solu...

Caracterização do Trabalho Experimental Realizado no Ensino Secundário e Estudo...

A Química, enquanto disciplina individual ou integrada na disciplina de Ciências Físico- Químicas, atravessa tempos difíceis. Considerada pelos alunos uma disciplina difícil, ela é, muitas vezes, preterida em relação a outras onde conseguem obter melhores resultados. Contudo, a Química dispõe de um recurso com potencialidades enormes no que se refere à motivação dos alunos: o Trabalho experimental. Nos currícul...

Progress in the catalysed hydrolysis of sodium borohydride as a gydrogen source...

Polyaniline coated conducting fabrics : chemical and electrochemical character...

Polyaniline coated conducting fabrics have been obtained by chemical oxidation of aniline by potassium peroxydisulfate on polyester fabrics. Two different acids have been employed to carry out the synthesis (HCl and H2SO4), obtaining the best results of conductivity with the latter one. The conducting fabrics have been characterized chemically by means of Fourier transform infrared spectroscopy with attenuated ...

A tripodal hydroxypyriminone-based compund and aluminium decorporation

Synthesis and complexation properties of a new 2-aminoalkylamino-4,5-dihydroxyp...

Organic resins functionalized with chiral salen complexes as heterogeneous cata...