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We revisit the problem of why stars become red giants. We modify the physics of a standard stellar evolution code in order to determine what does and what does not contribute to a star becoming a red giant. In particular, we have run tests to try to separate the effects of changes in the mean molecular weight and in the energy generation. The implications for why stars become red giants are discus
We present montage, a post-processing nucleosynthesis code that combines a traditional network for isotopes lighter than calcium with a rapid algorithm for calculating the s-process nucleosynthesis of the heavier isotopes. The separation of those parts of the network where only neutron-capture and beta-decay reactions are significant provides a substantial advantage in computational efficiency. We
An N-body code containing live stellar evolution through combination of the software packages nbody6 and stars is presented. Operational details of the two codes are outlined and the changes that have been made to combine them discussed. We have computed the evolution of clusters of 104 stars using the combined code and we compare the results with those obtained using nbody6 and the synthetic stel
There is an apparent dichotomy between the metal-poor ([Fe/H] ≤ -2) yet carbon-normal giants and their carbon-rich counterparts. The former undergo significant depletion of carbon on the red giant branch after they have undergone first dredge-up, whereas the latter do not appear to experience significant depletion. We investigate this in the context that the extra mixing occurs via the thermohalin
Models of stellar clusters link the theoretical gravitational N-body problem to the study of real astrophysical systems. Such models require a description of the stars contained within the cluster. Stars are interesting objects in their own right, and the study of stellar evolution is important across astronomy, from the formation of exotic objects such as X-ray binaries and gamma-ray bursts to me
This squib is a brief state of the art overview of declarative V1 in Icelandic, old and modern. Three(relevant) types of such clauses are discussed: Narrative Inversion, with an overt topical subjectdirectly after the verb, Presentational V1, with an overt non-topical subject, and Null-subject V1.Narrative Inversion is a robust main clause phenomenon, whereas Presentational V1 and Null-subjectV1 a
We use observations of M3 to constrain thermohaline mixing. This is done by matching [C/Fe] and [N/Fe] along the RGB of M3. We find our models can explain observations if it is assumed there is a spread of ∼ 0.3 - 0.4 dex in [C/Fe] in the stars in M3 from their birth. We reproduce the full spread in [C/Fe] at the tip of the RGB. Thermohaline mixing can produce a significant change in [N/Fe] as a f
The barium overabundances observed at the surface of barium stars originate from accretion long ago from the wind of a companion AGB star. However, this scenario cannot explain their high eccentricities and short orbital periods that have remained a mystery for decades. We investigate how kicks imparted to the white-dwarf at its birth or the presence of a circumbinary disk can solve this problem.
In this article we report on a systematic comparison of presentational sentencesin Icelandic and Swedish, looking in particular at possible thematicroles of the pivot and how they correlate with positional options. Despitesome well-known differences between the languages (only Icelandic allows‘high’ IP-pivots and pivots with transitive verbs), it turns out that the restrictionson VP-pivots are sim
HD 61396 has been identified as an X-ray and radio source and has shown Hα emission and photometric variability which have marked it out as an RS CVn star. Although it has been termed an RS CVn binary, hard evidence of its duplicity has been lacking. It is now shown to be a double-lined binary consisting of two giant stars, probably of almost equal size and luminosity but with a mass ratio of more
Paper on the film 'Chekovian Motifs' by Kira Muratova with the philosopher Michael Marder.
Intestinal mononuclear phagocytes, comprising macrophages (Mφs) and dendritic cells (DCs), play important roles in the generation and the regulation of immune responses to intestinal antigens, and alterations in the development and/or the function of these cells are thought to contribute to the pathogenesis of inflammatory bowel disease. In this review, we discuss the role of tumor necrosis factor
The typical acoustical treatment in ordinary rooms such as classrooms, offices, conference rooms etc is an absorbing suspended ceiling. Due to the non-uniform distribution of the absorbing material the sound field at steady-state and during sound decay is far from the ideal conditions assumed in the diffuse field theory. Especially during the sound decay, the degeneration of the sound field emphas
