Electron impact excitation of Mg VIII: Collision strengths, transition probabilities and theoretical EUV and soft X-ray line intensities for Mg VIII

Context: Mg VIII emission lines are observed in a range of astronomical objects such as the Sun, other cool stars and in the coronal line region of Seyfert galaxies. Under coronal conditions Mg VIII emits strongly in the extreme ultraviolet (EUV) and soft X-ray spectral regions which makes it an ideal ion for plasma diagnostics.

Aims. Two theoretical atomic models, consisting of 125 fine structure levels, are developed for the Mg VIII ion. The 125 levels arise from the 2s(2)2p, 2s(2)p2, 2p(3), 2s(2)3s, 2s(2)3p, 2s(2)3d, 2s2p3s, 2s2p3p, 2s2p3d, 2p(2)3s, 2p(2)3p and 2p(2)3d configurations. Electron impact excitation collision strengths and radiative transition probabilities are calculated for both Mg VIII models, compared with existing data, and the best model selected to generate a set of theoretical emission line intensities. The EUV lines, covering 312-790 angstrom, are compared with existing solar spectra (SERTS-89 and SUMER), while the soft X-ray transitions (69-97 angstrom) are examined for potential density diagnostic line ratios and also compared with the limited available solar and stellar observational data.

Methods. The R-matrix codes Breit-Pauli RMATRXI and RMATRXII are utilised, along with the PSTGF code, to calculate the collision strengths for two Mg VIII models. Collision strengths are averaged over a Maxwellian distribution to produce the corresponding effective collision strengths for use in astrophysical applications. Transition probabilities are also calculated using the CIV3 atomic structure code. The best data are then incorporated into the modelling code CLOUDY and line intensities generated for a range of electron temperatures and densities appropriate to solar and stellar coronal plasmas.

Results. The present effective collision strengths are compared with two previous calculations. Good levels of agreement are found with the most recent, but there are large differences with the other for forbidden transitions. The resulting line intensities compare favourably with the observed values from the SERTS-89 and SUMER spectra. Theoretical soft X-ray emission lines are presented and several density diagnostic line ratios examined, which are in reasonable agreement with the limited observational data available.

Radiative rates for E1, E2, M1, and M2 transitions in the Br-like ions Sr IV, Y V, Zr VI, Nb VII, and Mo VIII

Energies and lifetimes are reported for the lowest 375 levels of five Br-like ions, namely SrIV, YV, ZrVI, NbVII, and MoVIII, mostly belonging to the 4s²4p⁵, 4s²4p⁴4ℓ, 4s4p⁶, 4s²4p⁴5ℓ, 4s²4p³4d², 4s4p⁵4ℓ, and 4s4p⁵5ℓ configurations. Extensive configuration interaction has been included and the general-purpose relativistic atomic structure package (grasp) has been adopted for the calculations. Additionally, radiative rates are listed among these levels for all E1, E2, M1, and M2 transitions. From a comparison with the measurements, the majority of our energy levels are assessed to be accurate to better than 2%, although discrepancies between theory and experiment for a few are up to 6%. An accuracy assessment of the calculated radiative rates (and lifetimes) is more difficult, because no prior results exist for these ions.

Bestimmung des Kostenverlaufs von Molkereiabteilungen in Abhängigkeit von der Kapazitätsgröße und -auslastung. VIII. Teil: Buttereiabteilung

In der vorliegenden Arbeit werden die Produktionskosten für Sauerrahmbutter nach einer speziellen Form der Teilkostenrechnung in Abhängigkeit der Kapazitätsgröße und -auslastung bestimmt. Die untersuchten 3 Modelle haben eine Kapazität von 1350, 2700 und 4050 kg Butter/h. Durch Variation der Produktionsmengen von rd. 1600 bis 24 000 t/Jahr und der Produktionstage (360/252/180) er­geben sich Kosten der Buttereiabteilung zwischen 19,3 Pf/kg und 34,3 Pf/kg Butter. Bei einer mittleren Auslastung von 50% bewegen sich die Kosten von 20,3 bis 23,6 Pf/kg. Die Kostenanalyse zeigt, daß die Kostendegression bedeutend stärker durch den Kapazitätsauslastungsgrad als durch die Kapazitätsgröße beeinflußt wird.

O fuso e a trama: génese e identidade da ordem da Imaculada

Tese de mestrado, Estudos Românicos (Cultura Portuguesa), Universidade de Lisboa, Faculdade de Letras, 2011

Representações do ctonismo na cultura grega (séculos VIII-V a.C.)

Tese de doutoramento, História (História Antiga), Universidade de Lisboa, Faculdade de Letras, 2014

Monumens [sic] recueillis pour l'histoire de France par Mr de Gaignières - Maisons étrangères - 1ère Partie : Maison d'Anjou-Sicile. Ayant pour auteur Charles de France 7° fils de Louis VIII et frère de St Louis par son mariage avec Beatrix de Provence en 1246

Collectionneur : Gaignières, Roger de (1642-1715)

Rois et Reines de France et personnes de différentes qualités dessinés d'après des monumens [sic] : [dessin]. T. VII, Règnes de Louis XI, Charles VIII, Louis XII Années 1461 à 1525

Collectionneur : Gaignières, Roger de (1642-1715)

Rois et Reines de France et personnes de différentes qualités dessinés sur des monumens [sic] : [dessin]. T. VIII, Règnes de François Ier-Henry II Années 1514 à 1550

Collectionneur : Gaignières, Roger de (1642-1715)