27,143 research outputs found

    Educators as Empowerers: A Small-Scale Study of Opportunities to Expand the Scope of ITT Programmes, with a Particular Focus on Prison Education

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    This paper considers the scope of initial teacher training (ITT) programmes at UK universities and the extent to which they prepare teachers to empower learners outside of mainstream, compulsory schooling. Education is widely considered as a human right and an essential tool for social mobility, with the power to ‘enrich human capabilities and change behaviour’ (Cohen 2011: 4–5); in this paper, we explore the limitations of that in reality, considering educational provision, opportunities for funding and attitudes towards adult education. The paper compares attitudes towards school education and prison education, examining the potential for greater cohesion and the importance of rehabilitation. We draw on evidence from the literature; our own experience as ITT students and, subsequently, secondary school teachers; and a collaborative trainee teacher and prison learner programme between the School of Education, University of East London, and the prison HMP Isis. The paper concludes by discussing the potential for future, more inclusive ITT programmes which consider the role of education outside of schools, the implications of this and recommendations for the future

    Dissipation of dark matter

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    Fluids often display dissipative properties. We explore dissipation in the form of bulk viscosity in the cold dark matter fluid. We constrain this model using current data from supernovae, baryon acoustic oscillations and the cosmic microwave background. Considering the isotropic and homogeneous background only, viscous dark matter is allowed to have a bulk viscosity ≲107\lesssim 10^7 Pa⋅\cdots, also consistent with the expected integrated Sachs-Wolfe effect (which plagues some models with bulk viscosity). We further investigate the small-scale formation of viscous dark matter halos, which turns out to place significantly stronger constraints on the dark matter viscosity. The existence of dwarf galaxies is guaranteed only for much smaller values of the dark matter viscosity, ≲10−3\lesssim 10^{-3} Pa⋅\cdots.Comment: 10 pages, 3 figures, published in PR

    Experimental Generation and Observation of Intrinsic Localized Spin Wave Modes in an Antiferromagnet

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    By driving with a microwave pulse the lowest frequency antiferromagnetic resonance of the quasi 1-D biaxial antiferromagnet (C_2 H_5 NH_3)_2 CuCl_4 into an unstable region intrinsic localized spin waves have been generated and detected in the spin wave gap. These findings are consistent with the prediction that nonlinearity plus lattice discreteness can lead to localized excitations with dimensions comparable to the lattice constant.Comment: 10 pages, 4 figures, accepted for publication in Physical Review Letter

    Kinematic and morphological modeling of the bipolar nebula Sa2-237

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    We present [OIII]500.7nm and Halpha+[NII] images and long-slit, high resolution echelle spectra in the same spectral regions of Sa2--237, a possible bipolar planetary nebula. The image shows a bipolar nebula of about 34" extent, with a narrow waist, and showing strong point symmetry about the central object, indicating it's likely binary nature. The long slit spectra were taken over the long axis of the nebula, and show a distinct ``eight'' shaped pattern in the velocity--space plot, and a maximum projected outflow velocity of V=106km/s, both typical of expanding bipolar planetary nebulae. By model fitting the shape and spectrum of the nebula simultaneously, we derive the inclination of the long axis to be 70 degrees, and the maximum space velocity of expansion to be 308 km/s. Due to asymmetries in the velocities we adopt a new value for the system's heliocentric radial velocity of -30km/s. We use the IRAS and 21cm radio fluxes, the energy distribution, and the projected size of Sa2-237 to estimate it's distance to be 2.1+-0.37kpc. At this distance Sa2-237 has a luminosity of 340 Lsun, a size of 0.37pc, and -- assuming constant expansion velocity -- a nebular age of 624 years. The above radial velocity and distance place Sa2--237 in the disk of the Galaxy at z=255pc, albeit with somewhat peculiar kinematics.Comment: 10pp, 4 fig

    Quantum kk-core conduction on the Bethe lattice

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    Classical and quantum conduction on a bond-diluted Bethe lattice is considered. The bond dilution is subject to the constraint that every occupied bond must have at least k−1k-1 neighboring occupied bonds, i.e. kk-core diluted. In the classical case, we find the onset of conduction for k=2k=2 is continuous, while for k=3k=3, the onset of conduction is discontinuous with the geometric random first-order phase transition driving the conduction transition. In the quantum case, treating each occupied bond as a random scatterer, we find for k=3k=3 that the random first-order phase transition in the geometry also drives the onset of quantum conduction giving rise to a new universality class of Anderson localization transitions.Comment: 12 pgs., 6 fig

    Long beating wavelength in the Schwarz-Hora effect

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    Thirty years ago, H.Schwarz has attempted to modulate an electron beam with optical frequency. When a 50-keV electron beam crossed a thin crystalline dielectric film illuminated with laser light, electrons produced the electron-diffraction pattern not only at a fluorescent target but also at a nonfluorescent target. In the latter case the pattern was of the same color as the laser light (the Schwarz-Hora effect). This effect was discussed extensively in the early 1970s. However, since 1972 no reports on the results of further attempts to repeat those experiments in other groups have appeared, while the failures of the initial such attempts have been explained by Schwarz. The analysis of the literature shows there are several unresolved up to now contradictions between the theory and the Schwarz experiments. In this work we consider the interpretation of the long-wavelength spatial beating of the Schwarz-Hora radiation. A more accurate expression for the spatial period has been obtained, taking into account the mode structure of the laser field within the dielectric film. It is shown that the discrepancy of more than 10% between the experimental and theoretical results for the spatial period cannot be reduced by using the existing quantum models that consider a collimated electron beam.Comment: 3 pages, RevTe

    3-D Photoionization Structure and Distances of Planetary Nebulae II. Menzel 1

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    We present the results of a spatio-kinematic study of the planetary nebula Menzel 1 using spectro-photometric mapping and a 3-D photoionization code. We create several 2-D emission line images from our long-slit spectra, and use these to derive the line fluxes for 15 lines, the Halpha/Hbeta extinction map, and the [SII] line ratio density map of the nebula. We use our photoionization code constrained by these data to derive the three-dimensional nebular structure and ionizing star parameters of Menzel 1 by simultaneously fitting the integrated line intensities, the density map, and the observed morphologies in several lines, as well as the velocity structure. Using theoretical evolutionary tracks of intermediate and low mass stars, we derive a mass for the central star of 0.63+-0.05 Msolar. We also derive a distance of 1050+_150 pc to Menzel 1.Comment: To be published in ApJ of 10th February 2005. 12 figure
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