1,554 research outputs found

    Multiscale non-adiabatic dynamics with radiative decay, case study on the post-ionization fragmentation of rare-gas tetramers

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    In this supplementary material, we recollect, for reader's convenience, the general scheme of suggested multiscale model (Sec. 1), and basic informations about approaches used for pilot study: a detailed description of the interaction model (Sec. 2) and dynamical methods used for the dark dynamics step (Sec. 3) reported previously in two preceding studies [1, 2]. In addition, a detailed description of the treatment of radiative processes is also given (Sec. 4).Comment: supplementary material for parent paper; 9 pages, 1 figure; corrected formulae and misleading notation in Sec.4 (pages 7 and 8

    HOMOGENEOUS RIEMANNIAN STRUCTURES ON BERGER 3-SPHERES

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    Information flow between parents and offspring is essential for successful development

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    Over the last several decades, the sciences of developmental biology and physiology have expanded and intertwined their scope enormously [...

    Prospects for measurement and control of the scattering length of metastable helium using photoassociation techniques

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    A numerical investigation of two-laser photoassociation (PA) spectroscopy on spin-polarized metastable helium (He*) atoms is presented within the context of experimental observation of the least-bound energy level in the scattering potential and subsequent determination of the s-wave scattering length. Starting out from the model developed by Bohn and Julienne [Phys. Rev. A \textbf{60}, (1999) 414], PA rate coefficients are obtained as a function of the parameters of the two lasers. The rate coefficients are used to simulate one- and two-laser PA spectra. The results demonstrate the feasibility of a spectroscopic determination of the binding energy of the least-bound level. The simulated spectra may be used as a guideline when designing such an experiment, whereas the model may also be employed for fitting experimentally obtained PA spectra. In addition, the prospects for substantial modification of the He* scattering length by means of optical Feshbach resonances are considered. Several experimental issues relating to the numerical investigation presented here are discussed.Comment: 9 pages, 7 figure

    Caracterización de placas de yeso con residuos de espuma de poliuretano reforzadas con fibras de polipropileno

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    Gypsum plasterboard that incorporates various combinations of polyurethane foam waste and polypropylene fibers in its matrix is studied. The prefabricated material was characterized in a series of standardized tests: bulk density, maximum breaking load under flexion stress, total water absorption, surface hardness, thermal properties, and reaction to fire performance. Polypropylene fibers were added to the polyurethane gypsum composites to improve the mechanical behavior of the plasterboard under loading. The results indicate that increased quantities of polymer waste led to significant reductions in the weight/surface ratio, the mechanical strength and the surface hardness of the gypsum, as well as improving its thermal resistance. The polypropylene fibers showed good adhesion to the polymer and the gypsum matrix, which enhanced the mechanical performance and the absorption capacity of these compounds. The non-combustibility test demonstrated the potential of the new material for use in internal linings.Este artículo presenta un estudio experimental basado en la reutilización de residuos de poliuretano en una matriz de yeso para elaborar una placa de yeso laminado. Las placas fueron caracterizadas mediante los ensayos normalizados de densidad aparente, carga de rotura máxima a flexión, absorción total de agua, dureza superficial y reacción al fuego. Se han introducido fibras de polipropileno en la matriz con el objetivo de aumentar la resistencia mecánica del material. Los resultados muestran que el incremento de residuo polimérico en el material implica importantes reducciones de peso, resistencia mecánica y dureza superficial, a la par que se mejora su resistencia térmica consiguiéndose valores similares a los comerciales. Las fibras de polipropileno mostraron una buena adhesión con el polímero, mejorando el comportamiento mecánico y la capacidad de absorción. El ensayo de reacción al fuego confirmó que los residuos de poliuretano pueden ser empleados en la fabricación de placas de yeso laminado en cumplimiento con la normativa
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