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 decreasing costs and increasing availability of electronic products of all kinds, including mobile phones, audio and video equipment, and personal computers and their accessories, coupled with advances in technology that rapidly make these products obsolete, foretell a growing disposal…

A wide kinetic study has been carried out under different conditions in TG and TG–MS for each material, at different operating conditions. Runs were carried out at three different atmospheres: N2, N2:O2 4:1 and N2:O2 9:1. In addition to the…

A kinetic study of the thermal decomposition of tomato plant has been carried out under different conditions by TG and TG–MS. A total of 24 experiments were performed in a nitrogen atmosphere (pyrolysis runs) and also in an oxidative atmosphere…

Los sonetos de Luis de Sandoval Zapata han sido escasamente estudiados hasta el momento. En este ensayo se analizan varios sonetos desde el punto de vista de la tradición emblemática y se comenta cómo el significado e interpretación de los…

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…

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…

The electrocatalytic oxidation of ferrocene (Fc) at neutral pH in aqueous solution has been studied over thin films of electroactive sulfonated polyaniline (SPAN) by cyclic voltammetry. Strong adsorption of the oxidised species (ferrocenium ion) on the polymer arises as the…