The Atomic Physics Underlying the Spectroscopic Analysis of Massive Stars and Supernovae

We have developed a radiative transfer code, CMFGEN, which allows us to model the spectra of massive stars and supernovae. Using CMFGEN we can derive fundamental parameters such as effective temperatures and surface gravities, derive abundances, and place constraints on stellar wind properties. The last of these is important since all massive stars are losing mass via a stellar wind that is driven from the star by radiation pressure, and this mass loss can substantially influence the spectral appearance and evolution of the star. Recently we have extended CMFGEN to allow us to undertake time-dependent radiative transfer calculations of supernovae. Such calculations will be used to place constraints on the supernova progenitor, to place constraints on the supernova explosion and nucleosynthesis, and to derive distances using a physical approach called the "Expanding Photosphere Method". We describe the assumptions underlying the code and the atomic processes involved. A crucial ingredient in the code is the atomic data. For the modeling we require accurate transition wavelengths, oscillator strengths, photoionization cross-sections, collision strengths, autoionization rates, and charge exchange rates for virtually all species up to, and including, cobalt. Presently, the available atomic data varies substantially in both quantity and quality.Comment: 8 pages, 2 figures, Accepted for publication in Astrophysics & Space Scienc

Schuldig landschap. Over de toeristische aantrekkingskracht van Baantjer, Wallander en Inspector Morse

De opnamelokaties van tv-detectives genieten een toenemende populariteit onder toeristen. In dit artikel wordt, op basis van een tekstuele analyse van ‘Baantjer’, ‘Inspector Morse’ en ‘Wallander’, onderzocht welke inhoudelijke kenmerken van deze tv-detectives mogelijk als ‘trigger’ fungeren. Uit de analyse blijkt dat plaats en beweging een centrale rol vervullen binnen de narratieve structuur van dit genre. Door zelf de lokaties te bezoeken, kunnen toeristen het spoor nalopen van hun geliefde detective om aldaar, vanuit een veilige positie, tijdelijk op te gaan in het schemergebied tussen fictie en werkelijkheid

Ruinas, círculos, construcciones

This article is organized around three groups of 'citations' from architectural forms, texts, images, which generate three options of imagination, representation and reading of space: ruins, circular constructions, and rhetoric (in particular figures of repetition). I discuss the story of Borges "Las ruinas circulares" and examples from Iain Sinclair, London orbital (2002), Gianni Biondillo and Michele Monina, Tangenziali. Due viandanti ai bordi della città (2010), and Nicolò Bassetti, Sapo Matteucci, Sacro romano GRA (2013). The circularity generates a repetitive and disparate look allowing the observation of a complementary rhythm of destruction and construction characteristic of progress in the world

The ELFIN mission

The Electron Loss and Fields Investigation with a Spatio-Temporal Ambiguity-Resolving option (ELFIN-STAR, or heretoforth simply: ELFIN) mission comprises two identical 3-Unit (3U) CubeSats on a polar (∼93∘ inclination), nearly circular, low-Earth (∼450 km altitude) orbit. Launched on September 15, 2018, ELFIN is expected to have a >2.5 year lifetime. Its primary science objective is to resolve the mechanism of storm-time relativistic electron precipitation, for which electromagnetic ion cyclotron (EMIC) waves are a prime candidate. From its ionospheric vantage point, ELFIN uses its unique pitch-angle-resolving capability to determine whether measured relativistic electron pitch-angle and energy spectra within the loss cone bear the characteristic signatures of scattering by EMIC waves or whether such scattering may be due to other processes. Pairing identical ELFIN satellites with slowly-variable along-track separation allows disambiguation of spatial and temporal evolution of the precipitation over minutes-to-tens-of-minutes timescales, faster than the orbit period of a single low-altitude satellite (Torbit ∼ 90 min). Each satellite carries an energetic particle detector for electrons (EPDE) that measures 50 keV to 5 MeV electrons with Δ E/E 1 MeV. This broad energy range of precipitation indicates that multiple waves are providing scattering concurrently. Many observed events show significant backscattered fluxes, which in the past were hard to resolve by equatorial spacecraft or non-pitch-angle-resolving ionospheric missions. These observations suggest that the ionosphere plays a significant role in modifying magnetospheric electron fluxes and wave-particle interactions. Routine data captures starting in February 2020 and lasting for at least another year, approximately the remainder of the mission lifetime, are expected to provide a very rich dataset to address questions even beyond the primary mission science objective.Published versio

Advances in market targeting in tourism marketing analysis

SIGLEAvailable from British Library Document Supply Centre-DSC:DX209230 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Pharmacy-implemented guidelines on switching from intravenous to oral antibiotics: an intervention study

A high proportion of medical in-patients in the UK receive intravenous (IV) antibiotic therapy. This may be inappropriate in non-severe infections, or unnecessarily prolonged. Data relating to infection and antibiotic therapy were collected for 4 weeks pre-intervention (group 1) and 4 weeks post intervention (group 2). Six months later, data were collected for a further 4 weeks following a second intervention (group 3). Interventions consisted of pharmacy-led implementation of guidelines incorporating criteria for IV therapy and switching to the oral route. The second intervention also included pharmacy-initiated feedback on prescribing. The main outcome measures were IV antibiotic duration, and appropriateness of the IV route and switching