An experimental apparatus was designed and built to allow students to carry out heat conduction experiments in hollow cylinders made of different materials, as well as to determine the thermal conductivity of these materials. The evolution of the temperature difference…

A new aqueous photopolymer containing the monomers acrylamide, N,N'-methylenbisacrylamide and zinc acrylate, the initiators 4,5-diiodosuccinylfluorescein (2ISF) and methylene blue (MB), and the coinitiator sodium p-toluenesulphinate is described. This formulation exhibits a clear enhancement of the high-energy sensitivity upon irradiation with…

A model is proposed which allows us to obtain the diffraction efficiency of photopolymeric materials with a nonlinear response to the refraction index, using the equations on the evolution of copolymerization reactions as a base. The photochemical material being analysed…

We report an experimental-theoretical study of the energy-loss straggling of protons and alpha particles in HfO2 films. In the case of H ions the experiments were performed in the energy range 40–1750 keV. For the lower energy interval (40–250 keV)…

When aberrations are small, it is possible to use wave aberration variance to obtain the position of the best image plane in both conventional and holographic optical systems. However, when aberrations increase, this measurement is not sufficient and it does…

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…

In this paper we present the theoretical analysis and experimental results of a holographic collimator made in silver halide sensitized gelatin. Diffraction efficiency up to 70% over the whole plate and wave aberration as low as 20-lambda in the maximum…

Equations are derived for determining third-order wavefront aberrations in the plane of the exit pupil from the known aberration in the plane of a holographic lens. Using the transformation equations of wavefront aberration when the plane of the exit pupil…

Two Lidstedt-Poincaré perturbation based methods are used to solve the nonlinear differential equation of a nonlinear oscillator having the square of the angular frequency depends quadratically on the velocity. Mickens published two interesting papers [1, 2] about this oscillator and…

In their comment, Qing-Yin and Pei derived another analytical approximate expression for the large-angle pendulum period, which they compare with other expressions previously published. Most of these approximate formulas are based on the approximation of the original nonlinear differential equation…