Copper nanoparticles (mainly as Cu2O) on titania have been shown to catalyze the multicomponent synthesis of propargylamines from aldehydes, amines, and alkynes (A3 coupling) effectively at 70 °C under solvent-free conditions. Both aromatic and aliphatic aldehydes and alkynes have been…

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…

The chemical nature of the surface of a granular activated carbon has been modified by heat treatment under nitrogen at 1000 °C followed by pyrolysis of propene in the 300–600 °C temperature range. Cracking of propene produces deposits of coke…

We present two methods, interferometry at the zero spatial frequency limit and analysis of diffracted orders for very low spatial frequency gratings, to characterize photopolymers with dispersed nematic liquid crystals. These methods provide us with real time information about the…

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…

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…

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…

This paper presents an algorithm for identifying noun-phrase antecedents of pronouns and adjectival anaphors in Spanish dialogues. We believe that anaphora resolution requires numerous sources of information in order to find the correct antecedent of the anaphor. These sources can…

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 presents a multilayered architecture that enhances the capabilities of current QA systems and allows different types of complex questions or queries to be processed. The answers to these questions need to be gathered from factual information scattered throughout…