A second-order modified rational harmonic balance method is used for approximately solve the nonlinear differential equation that governs the oscillations of a system typified as a mass attached to a stretched elastic wire for which the restoring force for this…

Activated carbon/polyaniline composites have been prepared using different electrochemical methods: single-step potentiostatic polymerization, multiple-step potentiostatic polymerization, and potentiodynamic polymerization with the anodic potential limits being fixed at either 0.75 or 1 V (vs Ag/AgCl). The prepared composite samples were characterized…

A major challenge in deploying robots into the real world is the design of an architectural framework which can provide extended, natural and effective interactions with people. Within this framework, key issues that need to be solved relate 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…

The purpose of this study was to describe the distribution of different swimsuits models used by male swimmers during all the finals at the 13th FINA World Championships, being held at Rome in 2009. Simultaneously, it was intended to verify…

The kinetics of the global thermal decomposition of a PET fibre cloth have been studied in three different atmospheres with nitrogen, 20 and 10% oxygen, using thermogravimetric analysis (TGA) between room temperature and 1050 K. Three different heating rates were…

Three numerical methods for calculating the point spread function for holographic optical elements in the presence of aberrations are analyzed. The starting point for the analytical formulation of the diffraction theory of aberrations for holographic optical elements is the Fresnel-Kirchhoff…

Phylogenetic relationships within Limonium (Plumbaginaceae) are evaluated using sequence data from three plastid regions (rbcL, the trnL intron, and the trnL-trnF intergenic spacer). Sixty-six species representing the major genera of Staticoideae, including representatives of all sections and genera formerly included…

This paper analyzes the effect on the optimal value of a given linear semi-infinite programming problem of the kind of
perturbations which more frequently arise in practical applications: those which affect the objective function and the right-hand-side coefficients of the…

A new analytical approximate expression for the period of the simple pendulum is obtained by using a heuristic but pedagogical derivation. This formula depends on two parameters obtained by comparing term-by-term the power-series expansions of the approximate and exact expressions…