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Aproximadamente 28 registro(s) hasta el momento: (journal)

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Recurso libre

Linearization of conservative nonlinear oscillators
Beléndez Vázquez, Augusto - Álvarez López, Mariela Lázara - Fernández Varó, Elena - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	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…
Fecha:	2009-01-26
Recurso:	RUA Docencia

Recurso libre

Approximation for a large-angle simple pendulum period
Beléndez Vázquez, Augusto - Rodes Roca, José Joaquín - Beléndez Vázquez, Tarsicio - Hernández Prados, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	An approximation scheme to obtain the period for large amplitude oscillations of a simple pendulum is analysed and discussed. The analytical approximate formula for the period is the same as that suggested by Hite (2005 Phys. Teach. 43 290), but…
Fecha:	2009-02-25
Recurso:	RUA Docencia

Recurso libre

Corrigendum to “Solution of the relativistic (an)harmonic oscillator using the harmonic balance method” [J. Sound Vib. 311 (2008) 1447–1456]
Beléndez Vázquez, Augusto - Pascual Villalobos, Carolina - Méndez Alcaraz, David Israel - Neipp López, Cristian

Formato:	info:eu-repo/semantics/article
Enlaces:	Descripción completa.
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

Birefringence of cellotape: Jones representation and experimental analysis
Beléndez Vázquez, Augusto - Fernández Varó, Elena - Francés Monllor, Jorge - Neipp López, Cristian

Formato:	info:eu-repo/semantics/article
Enlaces:	In this paper we analyze a simple experiment to study the effects of polarized light. A simple optical system composed of a polarizer, a retarder (cellotape) and an analyzer is used to study the effect on the polarization state of…
Fecha:	2010-03-22
Recurso:	RUA Docencia

Recurso libre

Approximate analytical solutions for the relativistic oscillator using a linearized harmonic balance method
Beléndez Vázquez, Augusto - Méndez Alcaraz, David Israel - Álvarez López, Mariela Lázara - Pascual Villalobos, Carolina - Beléndez Vázquez, Tarsicio

Formato:	info:eu-repo/semantics/article
Enlaces:	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…
Fecha:	2009-03-11
Recurso:	RUA Docencia

Recurso libre

Analytical approximate solutions for conservative nonlinear oscillators by modified rational harmonic balance method
Beléndez Vázquez, Augusto - Gimeno Nieves, Encarnación - Álvarez López, Mariela Lázara - Yebra Calleja, María Soledad - Méndez Alcaraz, David Israel

Formato:	info:eu-repo/semantics/article
Enlaces:	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…
Fecha:	2009-10-22
Recurso:	RUA Docencia

Recurso libre

Diffuse-object holograms in silver halide sensitized gelatin
Fimia Gil, Antonio - Pascual Villalobos, Inmaculada - Carretero López, Luis - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	This paper deals with diffuse-object holograms recorded in silver halide sensitized gelatin. Both the diffraction efficiency and the signal-to-noise ratio when reconstruction is done with different wavelengths are measured. The experimental results we obtained show that new theoretical models for…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

An integrated project for teaching the post-buckling of a slender cantilever bar
Beléndez Vázquez, Tarsicio - Neipp López, Cristian - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	We describe an integrated project that includes theoretical, numerical and experimental studies designed to facilitate teaching the non-linear post-buckling of a cantilever column to undergraduate mechanical engineering students. We present the differential equation governing the behaviour of this mechanical system…
Fecha:	2009-03-10
Recurso:	RUA Docencia

Recurso libre

Post-buckling of a cantilever column: a more accurate linear analysis of a classical nonlinear problem
Beléndez Vázquez, Augusto - Hernández Prados, Antonio - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Neipp López, Cristian - Beléndez Vázquez, Tarsicio

Formato:	info:eu-repo/semantics/article
Enlaces:	A more accurate analytical approximate expression for the slope at any point of the elastic curve of a slender cantilever column is obtained by using a heuristic but pedagogical derivation. This derivation is based on the linearization of the nonlinear…
Fecha:	2009-03-10
Recurso:	RUA Docencia

Recurso libre

10.

Harmonic balance approaches to the nonlinear oscillators in which the restoring force is inversely proportional to the dependent variable
Beléndez Vázquez, Augusto - Méndez Alcaraz, David Israel - Beléndez Vázquez, Tarsicio - Hernández Prados, Antonio - Álvarez López, Mariela Lázara

Formato:	info:eu-repo/semantics/article
Enlaces:	The second-order harmonic balance method is used to construct three approximate frequency-amplitude relations for a conservative nonlinear singular oscillator in which the restoring force is inversely proportional to the dependent variable. Two procedures are used to solve the nonlinear differential…
Fecha:	2009-01-26
Recurso:	RUA Docencia

Recurso libre

11.

A novel rational harmonic balance approach for periodic solutions of conservative nonlinear oscillators
Beléndez Vázquez, Augusto - Gimeno Nieves, Encarnación - Álvarez López, Mariela Lázara - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Méndez Alcaraz, David Israel

Formato:	info:eu-repo/semantics/article
Enlaces:	An analytical approximate procedure for a class of conservative single degree-of-freedom nonlinear oscillators with odd non-linearity is proposed. This technique is based on the generalized harmonic balance method in which analytical approximate solutions have rational forms. Unlike the classical harmonic…
Fecha:	2012-05-04
Recurso:	RUA Docencia

Recurso libre

12.

Linearized harmonic balancing approach for accurate solutions to the dynamically shifted oscillator
Beléndez Vázquez, Augusto - Rodes Roca, José Joaquín - Fuentes Rosillo, Rosa - García Llopis, Celia - Yebra Calleja, María Soledad - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	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 dynamically shifted oscillator. This nonlinear oscillator is described by an equation of motion…
Fecha:	2012-05-04
Recurso:	RUA Docencia

Recurso libre

13.

Higher accuracy approximate solution for oscillations of a mass attached to a stretched elastic wire by rational harmonic balance method
Gimeno Nieves, Encarnación - Álvarez López, Mariela Lázara - Yebra Calleja, María Soledad - Rosa Herranz, Julio Luis - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	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…
Fecha:	2012-05-04
Recurso:	RUA Docencia

Recurso libre

14.

Axial irradiance and entropy of holographic optical elements under illumination with quasi-monochromatic light
Carretero López, Luis - Beléndez Vázquez, Augusto - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	The chromatic sensitivity of holographic optical elements for use in optical interconnect systems is quantified using an entropy merit function. The influence of broad-band illumination on axial irradiance and intensity is studied showing that the best imaging point obtained with…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

15.

Method for the characterization of hologram processing
Bányász, Istvan - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	A novel method for the characterization of the processing of both absorption and phase holograms is proposed. Differently from the previous models, the square root of the diffraction efficiency of the processed hologram was directly related to the amplitude of…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

16.

Comparison of nonlinear characteristics of phase holograms processed by various combinations of developers and bleaching agents
Bányász, Istvan - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	Optical densities before bleaching and final Lin curves of planewave phase holograms recorded in Agfa—Gevaert 8E75HD emulsions were measured for various combinations of developers (AAC, Pyrogallol and Catechol) and bleaching agents (R-9 and EDTA). To characterize the processing, the square…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

17.

Bleached silver halide volume holograms recorded on Slavich PFG-01 emulsion: the influence of the developer
Neipp López, Cristian - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	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. In this paper we will study the influence of the…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

18.

Stabilization of volume gratings recorded in polyvinyl alcohol-acrylamide photopolymers with diffraction efficiencies higher than 90%
Gallego Rico, Sergi - Neipp López, Cristian - Ortuño Sánchez, Manuel - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Obtaining holographic volume gratings with high diffraction efficiencies that can be used under white light has been a serious problem for the polyvinyl alcohol-acrylamide-based photopolymers developed by other researchers. In this paper we propose to eliminate the residual monomer in…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

19.

Overmodulation control in the optimization of a H-PDLC device with ethyl eosin as dye
Ortuño Sánchez, Manuel - Riquelme Morell, Marina - Gallego Rico, Sergi - Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The response of a H-PDLC device is improved by means of a two-step method. First, component optimization—initiator system, crosslinker, and cosolvent—enables the diffraction efficiency of the hologram to be maximized. Second, the use of N-methyl-2-pyrrolidone in combination with N-vinyl-2-pyrrolidone prevents…
Fecha:	2013-12-04
Recurso:	RUA Docencia

Recurso libre

20.

Theoretical and experimental analysis of overmodulation effects in volume holograms recorded on BB-640 emulsions
Neipp López, Cristian - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Kogelnik's coupled-wave theory has provided a well-established basis for understanding how light propagates inside a volume hologram, giving an accurate approximation of the diffraction efficiency in this type of hologram. In this paper we elaborate on some aspects of the…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

21.

Reply to ‘Comment on “Approximation for the large-angle simple pendulum period”’
Beléndez Vázquez, Augusto - Rodes Roca, José Joaquín - Beléndez Vázquez, Tarsicio - Hernández Prados, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	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…
Fecha:	2009-09-03
Recurso:	RUA Docencia

Recurso libre

22.

Higher accurate approximate solutions for the simple pendulum in terms of elementary functions
Beléndez Vázquez, Augusto - Francés Monllor, Jorge - Ortuño Sánchez, Manuel - Gallego Rico, Sergi - Bernabeu Pastor, José Guillermo

Formato:	info:eu-repo/semantics/article
Enlaces:	A closed-form approximate expression for the solution of a simple pendulum in terms of elementary functions is obtained. To do this, the exact expression for the maximum tension of the string of the pendulum is first considered and a trial…
Fecha:	2010-05-03
Recurso:	RUA Docencia

Recurso libre

23.

An experiment in heat conduction using hollow cylinders
Ortuño Sánchez, Manuel - Márquez Ruiz, Andrés - Gallego Rico, Sergi - Neipp López, Cristian - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	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…
Fecha:	2011-06-20
Recurso:	RUA Docencia

Recurso libre

24.

Hybrid ternary modulation applied to multiplexing holograms in photopolymers for data page storage
Fernández Varó, Elena - Márquez Ruiz, Andrés - Gallego Rico, Sergi - Fuentes Rosillo, Rosa - García Llopis, Celia - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	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…
Fecha:	2011-07-18
Recurso:	RUA Docencia

Recurso libre

25.

Analytic expressions for the inelastic scattering and energy loss of electron and proton beams in carbon nanotubes
Emfietzoglou, Dimitris - Kyriakou, Ioanna - García Molina, Rafael - Abril Sánchez, Isabel - Kostarelos, Kostas

Formato:	info:eu-repo/semantics/article
Enlaces:	We have determined “effective” Bethe coefficients and the mean excitation energy of stopping theory (I-value) for multiwalled carbon nanotubes (MWCNTs) and single-walled carbon nanotube (SWCNT) bundles based on a sum-rule constrained optical-data model energy loss function with improved asymptotic properties.…
Fecha:	2012-11-29
Recurso:	RUA Docencia

Recurso libre

26.

Approximate expressions for the period of a simple pendulum using a Taylor series expansion
Beléndez Vázquez, Augusto - Arribas Garde, Enrique - Márquez Ruiz, Andrés - Ortuño Sánchez, Manuel - Gallego Rico, Sergi

Formato:	info:eu-repo/semantics/article
Enlaces:	An approximate scheme for obtaining the period of a simple pendulum for large-amplitude oscillations is analysed and discussed. When students express the exact frequency or the period of a simple pendulum as a function of the oscillation amplitude, and they…
Fecha:	2011-07-29
Recurso:	RUA Docencia

Recurso libre

27.

Inelastic scattering of electron and light ion beams in organic polymers
Vera Gomis, Pablo de - Abril Sánchez, Isabel - García Molina, Rafael

Formato:	info:eu-repo/semantics/article
Enlaces:	We have calculated the inelastic mean free path, stopping power, and energy-loss straggling of swift electron, proton, and α-particle beams in a broad incident energy range in four organic polymers: poly(methyl methacrylate) (PMMA), Kapton, polyacetylene (PA), and poly(2-vinylpyridine) (P2VP). These…
Fecha:	2012-11-29
Recurso:	RUA Docencia

Recurso libre

28.

Tensorial split-field finite-difference time-domain approach for second- and third-order nonlinear materials
Francés Monllor, Jorge - Tervo, Jani - Márquez Ruiz, Andrés

Formato:	info:eu-repo/semantics/article
Enlaces:	The split-field finite-difference time-domain (SF-FDTD) method for one-dimensionally periodic structures is extended to include the coefficient-tensor description of second- and third-order nonlinear-optical media. A set of nonlinear equations related to the split-field values of the electric field is established. An…
Fecha:	2013-09-06
Recurso:	RUA Docencia