Stark Broadening of Sn III Spectral Lines of Astrophysical Interest: Predictions and Regularities

The determination of the Stark broadening parameters of Sn ions is useful for astrophysicists interested in the determination of the density of electrons in stellar atmospheres. In this paper, we report on the calculated values of the Stark broadening parameters for 171 lines of Sn iii arising from 4d105sns (n= 6–9), 4d105snp (n= 5, 6), 4d105p2, 4d105snd (n= 5–7), 4d105s4f and 4d105s5g. Stark linewidths and line shifts are presented for an electron density of 1023 m−3 and temperatures T= 11 000–75 000 K. These have been calculated using a semi-empirical approach, with a set of wavefunctions obtained from Hartree–Fock relativistic calculations, including core polarization effects. The results obtained have been compared with available experimental data. These can be used to consider the influence of Stark broadening effects in A-type stellar atmospheres

Vanadium-Doped In and Sn Sulphides: Photocatalysts able to use the whole visible light spectrum

Using photocatalysis for energy applications depends, more than for environmental purposes or selective chemical synthesis, on converting as much of the solar spectrum as possible; the best photocatalyst, titania, is far from this. Many efforts are pursued to use better that spectrum in photocatalysis, by doping titania or using other materials (mainly oxides, nitrides and sulphides) to obtain a lower bandgap, even if this means decreasing the chemical potential of the electron-hole pairs. Here we introduce an alternative scheme, using an idea recently proposed for photovoltaics: the intermediate band (IB) materials. It consists in introducing in the gap of a semiconductor an intermediate level which, acting like a stepstone, allows an electron jumping from the valence band to the conduction band in two steps, each one absorbing one sub-bandgap photon. For this the IB must be partially filled, to allow both sub-bandgap transitions to proceed at comparable rates; must be made of delocalized states to minimize nonradiative recombination; and should not communicate electronically with the outer world. For photovoltaic use the optimum efficiency so achievable, over 1.5 times that given by a normal semiconductor, is obtained with an overall bandgap around 2.0 eV (which would be near-optimal also for water phtosplitting). Note that this scheme differs from the doping principle usually considered in photocatalysis, which just tries to decrease the bandgap; its aim is to keep the full bandgap chemical potential but using also lower energy photons. In the past we have proposed several IB materials based on extensively doping known semiconductors with light transition metals, checking first of all with quantum calculations that the desired IB structure results. Subsequently we have synthesized in powder form two of them: the thiospinel In2S3 and the layered compound SnS2 (having bandgaps of 2.0 and 2.2 eV respectively) where the octahedral cation is substituted at a â?10% level with vanadium, and we have verified that this substitution introduces in the absorption spectrum the sub-bandgap features predicted by the calculations. With these materials we have verified, using a simple reaction (formic acid oxidation), that the photocatalytic spectral response is indeed extended to longer wavelengths, being able to use even 700 nm photons, without largely degrading the response for above-bandgap photons (i.e. strong recombination is not induced) [3b, 4]. These materials are thus promising for efficient photoevolution of hydrogen from water; work on this is being pursued, the results of which will be presented.

Nota exacta de las missas, i, aniversaris se celebran en la Igl[esi]a Parr[oquia]l de Sn. Andreu de Vallgorguina per la Casa del Más Pujadas de dita Parroquia [Manuscrito]

Alcance y contenido: "Misas y Aniversaris deuhers celebrarse en la Igla. Parr[oqui]al de St. Andreu de Vallgorguina per los passats, o difunts de Casa Pujadas de dita Parr[oqui]a; distribuhidas, y distribuhits per los dotze mesos del any."

Mechanical Characterization of Lead-Free Sn-Ag-Cu Solder Joints by High-Temperature Nanoindentation

The reliability of Pb-free solder joints is controlled by their microstructural constituents. Therefore, knowledge of the solder microconstituents’ mechanical properties as a function of temperature is required. Sn-Ag-Cu lead-free solder alloy contains three phases: a Sn-rich phase, and the intermetallic compounds (IMCs) Cu6Sn5 and Ag3Sn. Typically, the Sn-rich phase is surrounded by a eutectic mixture of β-Sn, Cu6Sn5, and Ag3Sn. In this paper, we report on the Young’s modulus and hardness of the Cu6Sn5 and Cu3Sn IMCs, the β-Sn phase, and the eutectic compound, as measured by nanoindentation at elevated temperatures. For both the β-Sn phase and the eutectic compound, the hardness and Young’s modulus exhibited strong temperature dependence. In the case of the intermetallics, this temperature dependence is observed for Cu6Sn5, but the mechanical properties of Cu3Sn are more stable up to 200°C.

Vista de la ciudad de Valencia, tomada de Sn. Pío V [Material gráfico]

Inscripción en la parte inferior: "Vista de la ciudad de Valencia, tomada desde Sn. Pío V"

Noticia de la Fundación del Colegio de Sn. Pio 5º de P.P. Clerigos Menores extramuros de la Ciudad de Valencia [Manuscrito]

Alcance y contenido: Ms. que recoge brevemente la historia de la fundación del mencionado Colegio-Seminario de los CC. RR. MM. (Clérigos Regulares Menores), sus propositos, características de los alumnos, becas y estudios que se impartían desde su fundación en 1683 hasta el s. XIX. Este Colegio es donde ahora se ubica el Museo de San Pío V.

La Virgn. Santisa. de la Concordia [Material gráfico] : colocada sobre la puerta principal de la Yglesia parl. de Sn. Bartolomé de Val

Bajo la imagen y situada entre la inscripción, un escudo coronado con la cruz de caravaca

Sn. Francisco de Sales [Material gráfico]

Inscripción enla parte inferior derecha: "115"

Salvador del Mundo ; Sn, Juan Bautista [Material gráfico]

Inscripción en la parte central: "17"

Sn. Felipe Apóstol [Material gráfico] : Su fiesta á 1º de Mayo

Inscripción enla parte inferior derecha: "166"

Sn. Lorenzo Mr. [Material gráfico]

Inscripción en la parte inferior derecha: "14"

Vista general de Sn. Felipe [Material gráfico] = Vue genérale de St. Philippe = General view of St. Philip

Resumen: Descripción: vista general de la ciudad de San Felipe, Xátiva desde las afueras