This paper deals with the non-linear oscillation of a simple pendulum and presents an approach for solving the non-linear differential equation that governs its movement by using the harmonic balance method. With this technique it is possible to easily obtain…

The harmonic balance method is used to construct approximate frequency–amplitude relations and periodic solutions to the relativistic oscillator. By combining linearization of the governing equation with the harmonic balance method, we construct analytical approximations to the oscillation frequencies and periodic…

In this paper we present the study of the electrochemical properties of the following conducting polymers: poly(o-anisidine),
polyaniline and copolymers of aniline and o-anisidine obtained by a new synthetic method. The polymers are synthesized
in free-of-acid conditions, using an activated…

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Data Warehouses manage historical information for the decision making process, and this information could be discovered by unauthorized users if security constraints are not established. It is therefore highly important for OLAP tools to consider the security rules defined at…

Numerical calculation of Fresnel patterns through fast Fourier transforms usually requires an extremely large number of samples in order to fulfil the Nyquist sampling condition. In many applications, the cut-off frequency of the system is much below the limit fixed…

Objectives: The fall of the Wall in 1989 can be seen as a natural experiment in the epidemiological sense to further examine the relation between democracy and health. Design and setting: Ecological study in the 23 post-communist countries, during the…

In this work we study the effect of the glass substrate on the efficiencies of the different orders that propagate inside a transmission sinusoidal diffraction grating. Holographic optical elements are usually recorded on a photosensitive medium deposited on to a…

Choline, the precursor and the metabolite of acetylcholine, is reputed as a selective α7 nicotinic receptor agonist. In this study, however, we
have seen that choline exerted a dual effect on bovine nicotinic receptors expressed in Xenopus oocytes. On the…

A review of all known descriptions of immature stages of the species of the genera Scaeva Fabricius, 1805, Ischiodon Sack, 1913 and Simosyrphus Bigot, 1882 is presented using SEM illustrations. The third instar larval and/or pupal morphology of Scaeva dignota…