A theoretical study of transition probabilities and lifetimes for the Sn III: core polarization effects

Data on atomic properties are not only relevant to spectroscopy, but these values are of interest in a variety of other fields in physics and technology. In this work we present a completer study of Sn III transition probabilities and lifetimes of spectral lines arising from 4d105sns (n=6-9) and 4d105snp (n=5-6) configurations These values were obtained in intermediate coupling (IC) and using relativistic Hartree-Fock calculations including core-polarization effects following the suggestions of Migdalek et al. [1]. We use for the IC calculations the standard method of least square fitting from experimental energy levels by means of Cowan [2] computer code. For the calculations we used all the experimental levels present in the Moore table. Transition probabilities and lifetimes are generally in good agreement with the experimental data [3, 4, 5]. In the next Table we present some values as example

Core-polarization Effects for the Stark Broadening of Pb III Spectral Lines: Predictions and Regularities

Using a semi-classical approach, we have calculated values of the Stark broadening parameters for several lines of Pb III. Stark widths and shifts are presented for an electron density of 1017 cm¿ 3 and temperatures T = 11000-100000 K. In this work, we have carried out a study of the influence of the introduction of the terms that allow us to take into account the Core Polarization (CP) effects in the calculation of the Stark broadening parameters. Our results are compared with available experimental and theoretical data. Common trends for the several lines have been found and are discussed

Acciones de acogida del proyecto mentor de la EUITI

Desde el curso académico 2008/2009 el Proyecto Mentor de la Escuela Universitaria de Ingeniería Técnica Industrial (EUITI) de la UPM [1] participa en distintas acciones de acogida de los alumnos de nuevo ingreso propio del centro. Estas actividades son el primer contacto de los mentores con los alumnos de nuevo ingreso y además son reforzadas por el apoyo y experiencia de los tutores y mentores del curso anterior, favoreciendo la interrelación de alumnos de distintos cursos y especialidades. Para la correcta realización de estas actividades, los alumnos mentores reciben un intensivo programa de formación que incluye aspectos psicosociales propios de la mentoría [2]. La presente comunicación tiene el propósito de describir dichas acciones así como presentar y valorar los resultados obtenidos a través de la encuest

Theoretical study of the Stark width and shift parameters of Pb III lines: predictions and regularities

Semiclassical approximate values of the Stark parameters for several lines of Pb III are reported in this paper. The parameters were calculated using a set of wavefunctions obtained from Hartree–Fock relativistic calculations. Stark widths for 122 lines of Pb III arising from 5d¹⁰6s np (n=6,7,8), 5d¹⁰6s ns (n=7,8,9) and 5d¹⁰6s nd (n = 6,7) configurations have been calculated in this way. Stark widths and shifts are presented as a function of temperature for an electron density of 10¹⁷ cmˉ³. Our results are compared with available experimental data. These atomic data are relevant to the analysis of isotopic abundances of Pb III found in the atmospheres of the star χ Lupy and several subdwarf B and OB stars

Core-polarization effects, oscillator strengths and radiative lifetimes of levels in Pb III

Transition probabilities and oscillator strengths of 382 lines with astrophysical interest arising from 5d⁹6s²6p, 5d¹⁰6snl, 5d¹⁰6s2, 5d¹⁰6p², 5d¹⁰6p7s and 5d¹⁰6p6d configurations and some levels radiative lifetimes of Pb III have been calculated. These values were obtained in intermediate coupling (IC) and using relativistic Hartree–Fock calculations including corepolarization effects. We use for the IC calculations the standard method of least-square fitting from experimental energy levels by means of Cowan computer code. The inclusion in these calculations of the 5d¹⁰6p7s and 5d¹⁰6p6d configurations has facilitated us a complete assignment of the levels of energy in the Pb III. Transition probabilities, oscillator strengths and radiative lifetimes obtained are generally in good agreement with the experimental data

Level energies, oscillator strengths and lifetimes for transitions in Pb IV

Oscillator strengths for several lines of astrophysical interest arising from some configurations and some levels radiative lifetimes of Pb IV have been calculated. These values were obtained in intermediate coupling (IC) and using ab initio relativistic Hartree-Fock calculations. We use for the IC calculations the standard method of least square fitting of experimental energy levels by means of computer codes from Cowan. Transition probabilities and oscillator strengths obtained, although in general agreement with the rare experimental data, do present some noticeable discrepancies that are studied in the text

A Comparison of the Effects of Various Purification Treatments on the Oxidative Stability of Squid Visceral Oil

Transitions probabilities for several lines arising from excited levels of Ge I, Bi I, and Tl I have from determined from emission lines intensities in a hollow-cathode discharge. These values were put on an absolute scale by using, were possible, the experimental lifetimes published by others authors. Oscillator strengths for several lines interest arising from some configurations and some levels radiative lifetimes of these elements have been calculated