370 resultados para Rodolfo Walsh
Resumo:
We have developed a high-resolution combined physical and chemical model of a protoplanetary disk surrounding a typical T Tauri star. Our aims were to use our model to calculate the chemical structure of disks on small scales (submilliarcsecond in the inner disk for objects at the distance of Taurus, ~140 pc) to investigate the various chemical processes thought to be important in disks and to determine potential molecular tracers of each process. Our gas-phase network was extracted from the UMIST Database for Astrochemistry to which we added gas–grain interactions including freezeout and thermal and non-thermal desorption (cosmic-ray-induced desorption, photodesorption, and X-ray desorption), and a grain-surface network. We find that cosmic-ray-induced desorption has the least effect on our disk chemical structure while photodesorption has a significant effect, enhancing the abundances of most gas-phase molecules throughout the disk and affecting the abundances and distribution of HCN, CN, and CS, in particular. In the outer disk, we also see enhancements in the abundances of H2O and CO2. X-ray desorption is a potentially powerful mechanism in disks, acting to homogenize the fractional abundances of gas-phase species across the depth and increasing the column densities of most molecules, although there remain significant uncertainties in the rates adopted for this process. The addition of grain-surface chemistry enhances the fractional abundances of several small complex organic molecules including CH3OH, HCOOCH3, and CH3OCH3 to potentially observable values (i.e., a fractional abundance of greater than 10-11).
Resumo:
Whilst the project to increase workforce mobility is part of a common labour force policy across the European Union, for some social workers, it has also been coupled with an aspiration to develop a pan-European identity within the profession (Lorenz, 1994, 2000; Frost, 2008). In this article, taking the island of Ireland as an example, we examine empirical data on the movement of social workers in recent years, both within Ireland and inward from outside the island, and consider the challenges and opportunities this has presented for the profession, also drawing on the British experience. From this analysis, some tentative conclusions are drawn about what is happening, what is possible and what is desirable in balancing aspirations for increased mobility within the European Union and a pan-European social work identity against the needs and interests of local, European and global communities.
Resumo:
The purpose of this paper, which builds on an earlier paper published in this Journal (Vol. 20, No. 6), is to develop the discussion around how English has been taught, used and perceived in Kenya, using data gathered from a small second-level English-medium school in Kenya. The complex relationships between language and identity are at work in the everyday routines of both staff and pupils within such a context. The paper seeks to set out a clear methodology for gathering data which could help describe these relationships with more clarity while also subjecting the data to analysis informed by the growing body of research and theory that focuses on language policy in post-colonial and neo-colonial settings. Finally, these pieces of data are used as the basis of a further exploration of the implications for classroom practice in teaching English in this environment.
Resumo:
Cross-curricularity, literacy and critical literacy are currently promoted as components of a curriculum appropriate for the 21st century. The first two in particular are prescribed elements of classroom experience in Northern Ireland, which is the immediate context of this article, but also more widely in the UK. Teachers are implementing cross-curricular and inter-disciplinary initiatives, but rhetorical imperatives can translate into superficial realities. The reasons for this are explored, as are the reasons why inter-disciplinary studies, literacy across the curriculum and critical literacy are deemed to be of significance for education at the present time. The ‘Making Science: Making News’ project is described, in which Key Stage 3 Science and English classes worked together, with input from a research scientist and a journalist, to produce articles on space science which were published in local newspapers. The outcomes of the project are discussed from the perspectives of both teachers and learners. It is argued that this project is an example of genuine inter-disciplinary activity; that it went beyond literacy skills to a deeper development of scientific discourse; and that, through its media connection, there was potential for building an ongoing awareness in pupils of critical literacy and scientific literacy.