Nanostructured cobalt oxide (Co3O4) electrodes were prepared by two different methods. The first one involved the synthesis of Co3O4 nanoparticles through a nanocasting route using commercial silica gel as a sacrificial template, and in the second one, the Co3O4 electrodes…

A linearization method of the nonlinear differential equation for conservative nonlinear oscillators is analyzed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force which allows us to obtain a frequency-amplitude relation which is valid…

Holographic data storage is a new optical technology, which allows an important number of bits to be stored in a recording material. In this paper, holographic data pages were stored in a polyvinyl alcohol/acrylamide (AA) photopolymer layer, using a peristrophic…

Virtual and remote laboratories have improved
learning and training in the academic community. They allow students to acquire methods, skills and experience related to real equipment in an intuitive and cost-effective way. The purpose of this paper is to present…

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…

The templated growth of polyaniline through porous sol–gel films on ITO substrates has been performed. The polyaniline–silica composites have been synthesized by electrochemical reactive insertion in potentiodynamic and potentiostatic conditions. When the polymer is synthesized by potential step experiments, the…

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…

In this paper we study the distribution of the zeros of each function G_{n}(z)≡1+2^{z}+...+n^{z}, n≥2, which approaches the Riemann zeta function for Rez<-1, and is closely related to the solutions of the functional equations f(z)+f(2z)+...+f(nz)=0. We determine the density of…

Descripción completa.

The analytical approximate technique developed by Wu et al. for conservative oscillators with odd nonlinearity is used to construct approximate frequency-amplitude relations and periodic solutions to the relativistic oscillator. By combining Newton's method with the method of harmonic balance, analytical…