The electrochemical reduction of perchloroethylene (PCE) in water has been analyzed through voltammetric studies with a
rotating disc electrode and controlled potential bulk electrolysis. The influence of the mass transport conditions and initial concentration on lead, copper and carbon electrodes…

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An approximation scheme to obtain the period for large amplitude oscillations of a simple pendulum is analysed and discussed. The analytical approximate formula for the period is the same as that suggested by Hite (2005 Phys. Teach. 43 290), but…

3,3'-Bis(dialkylaminomethyl)-1,1'-binaphth-2-ols (Binolams) have emerged during the last five years as very efficient chiral ligands in many enantioselective processes. Enantiomerically pure Binolams are easily accessible by means of a variety of methods, the most widely used being the so-called chiral Binol…

Dans ce mémoire, nous proposons l’étude des représentations sociales du politique dans la presse quotidienne. Notre objet d’étude est le sens de la nation au Québec dans une période historique où la notion idéologique de nation s’avère un cadre de…

Evaluations are provided of 21 descriptors of Posidonia oceanica meadows along the coast of Valencia, Spain, with a view to using these in implementing the European Water Framework Directive (WFD). The descriptors selected are known to respond to a variety…

The bibliographic impact factor (BIF) of Thomson Scientific is sometimes not a valid scientometric indicator for a number of reasons. One major reason is the strong influence of the number of “source items” or “articles” for each journal that the…

We studied the phylogeny and systematics of the tribe Paragini (Diptera: Syrphidae) using morphological and molecular data. The paper presents separate parsimony analyses of both adult morphological characters and partial DNA sequence data from mitochondrial cytochrome c oxidase I and…

An analytical approximate technique for conservative nonlinear oscillators is proposed. This method is a modification of the generalized harmonic balance method in which analytical approximate solutions have rational form. This approach gives us not only a truly periodic solution but…

The second-order harmonic balance method is used to construct three approximate frequency-amplitude relations for a conservative nonlinear singular oscillator in which the restoring force is inversely proportional to the dependent variable. Two procedures are used to solve the nonlinear differential…