Silver halide sensitized gelatin (SHSG) is one of the most promising techniques for the fabrication of transmission holographic optical elements, achieving relatively high sensitivity of photographic material with the low scattering and high light stability of dichromated gelatin. In this…

Bleached holograms are one of the most interesting techniques used to produce phase holograms of high quality on photographic emulsions. Of particular interest is the method of fixation-free rehalogenating bleaching. Using Kogelnik's coupled-wave theory we shall obtain information about the…

The 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(Sa)-Binap·AuTFA]2. The alanine-derived oxazolone only reacts with tert-butyl acrylate giving anomalous regiochemistry, which is explained and supported by Natural Resonance Theory and Nucleus Independent…

This paper describes two in vitro regeneration systems through direct and indirect organogenesis in Pinus brutia using fascicles aseptic cultures as explants. Mechanical scarification and gibberellic acid (GA3) were evaluated on in vitro seed germination. Scarification was the treatment that…

The asymptotic behaviours for small and large amplitudes, A, of the period for a nonlinear oscillator, where the square of the angular frequency depends quadratically on the velocity, are obtained. These asymptotic expressions are compared with the exact period, T(A),…

Technical teaching often requires the use of expensive laboratory materials which are frequently beyond the reach of many students. Students are also required to go to laboratories, which offer the appropriate facilities, according to a strict timetable. For these reasons,…

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…

This paper deals with the problem of planning the Center of Mass (CoM) trajectory of a humanoid robot while its feet follow an omnidirectional walking pattern. This trajectory should satisfy the dynamic stability criterion to ensure analytically that the Zero…

The redox process undergone by the electrochemically synthesized poly(2,2-dithiodianiline), poly(DTDA), has been examined in
acetonitrile-water mixtures by electrochemical and spectroscopic techniques. The spectroscopic properties of this material are equivalent to those exhibited by the chemically synthesized one. The polymeric structure…

El Espectador sevillano, redactado por Alberto Lista, se publicó en Sevilla del 2 de octubre de 1809 al 29 de enero de 1810. Aunque se trata de uno de los periódicos más importantes del momento, se le ha estudiado poco.…