3,300 research outputs found

    The difficulties of judging what difference the Pupil Premium has made to school intakes and outcomes in England.

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    Pupil Premium funding has been provided to schools in England since 2011, to help overcome socio-economic segregation between schools, and reduce the attainment gap between disadvantaged pupils and their peers – nationally, regionally, and within individual schools. Yet there is little international evidence that such a funding system can raise attainment directly. Some important stakeholders are now considering whether Pupil Premium should cease, be used for more general school financing, or have a new objective such as social mobility. It is therefore essential to know whether the policy has had a beneficial impact in the eight years since its inception. Previous estimates suggest that segregation and the raw attainment gap have been reducing erratically and slowly since 2011, but that this is generally part of a longer-term historical trend and cannot simply be attributed to the Pupil Premium policy. However, evaluating the impact of such a funding policy is not that simple. It is fraught with difficulties because of changes over time in the economy, legal definitions of indicators of disadvantage, the prevalence of disadvantage, the metrics used, and in the ways attainment has been summarised. Previous research has generally not taken these into account and also largely ignores the length and depth of disadvantage, and the difference this makes to patterns of attainment. Hence, previous estimates of the attainment gap are probably insecure. To illustrate the problems arising in judging changes over time and between areas and schools in segregation and the attainment gap, data from the National Pupil Database and School-level Annual Schools Census are correlated, cross-plotted, and modelled using regression, and time series analyses. This paper introduces a new analysis that considers changes in the prevalence of FSM-eligibility, private school attendance, GDP and the duration of individual poverty. It illustrates the importance of these factors in an analysis of the attainment gap in each local authority in England. Net of such factors, the results show that segregation has declined unexpectedly since 2011, suggesting that Pupil Premium may be working. The Pupil Premium policy should remain until further research is complete, and in the meantime claims of the relative success and failure of schools and regions should take into account the cautions noted in this paper

    Improving the Efficiency of an Ideal Heat Engine: The Quantum Afterburner

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    By using a laser and maser in tandem, it is possible to obtain laser action in the hot exhaust gases involved in heat engine operation. Such a "quantum afterburner" involves the internal quantum states of working gas atoms or molecules as well as the techniques of cavity quantum electrodynamics and is therefore in the domain of quantum thermodynamics. As an example, it is shown that Otto cycle engine performance can be improved beyond that of the "ideal" Otto heat engine.Comment: 5 pages, 3 figure

    One-loop Beta Functions for the Orientable Non-commutative Gross-Neveu Model

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    We compute at the one-loop order the beta-functions for a renormalisable non-commutative analog of the Gross Neveu model defined on the Moyal plane. The calculation is performed within the so called x-space formalism. We find that this non-commutative field theory exhibits asymptotic freedom for any number of colors. The beta-function for the non-commutative counterpart of the Thirring model is found to be non vanishing.Comment: 16 pages, 9 figure

    Dynamical generalization of a solvable family of two-electron model atoms with general interparticle repulsion

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    Holas, Howard and March [Phys. Lett. A {\bf 310}, 451 (2003)] have obtained analytic solutions for ground-state properties of a whole family of two-electron spin-compensated harmonically confined model atoms whose different members are characterized by a specific interparticle potential energy u(r12r_{12}). Here, we make a start on the dynamic generalization of the harmonic external potential, the motivation being the serious criticism levelled recently against the foundations of time-dependent density-functional theory (e.g. [J. Schirmer and A. Dreuw, Phys. Rev. A {\bf 75}, 022513 (2007)]). In this context, we derive a simplified expression for the time-dependent electron density for arbitrary interparticle interaction, which is fully determined by an one-dimensional non-interacting Hamiltonian. Moreover, a closed solution for the momentum space density in the Moshinsky model is obtained.Comment: 5 pages, submitted to J. Phys.

    Bosonized noncommutative bi-fundamental fermion and S-duality

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    We perform the path-integral bosonization of the recently proposed noncommutative massive Thirring model (NCMT1_{1}) [JHEP0503(2005)037]. This model presents two types of current-current interaction terms related to the bi-fundamental representation of the group U(1). Firstly, we address the bosonization of a bi-fundamental free Dirac fermion defined on a noncommutative (NC) Euclidean plane \IR_{\theta}^{2}. In this case we show that the fermion system is dual to two copies of the NC Wess-Zumino-Novikov-Witten model. Next, we apply the bosonization prescription to the NCMT1_{1} model living on \IR_{\theta}^{2} and show that this model is equivalent to two-copies of the WZNW model and a two-field potential defined for scalar fields corresponding to the global U(1)×U(1)U(1)\times U(1) symmetry plus additional bosonized terms for the four fermion interactions. The bosonic sector resembles to the one proposed by Lechtenfeld et al. [Nucl. Phys. B705(2005)477] as the noncommutative sine-Gordon for a {\sl pair} of scalar fields. The bosonic and fermionic couplings are related by a strong-weak duality. We show that the couplings of the both sectors for some representations satisfy similar relationships up to relevant re-scalings, thus the NC bi-fundamental couplings are two times the corresponding ones of the NC fundamental (anti-fundamental) and eight times the couplings of the ordinary massive Thirring and sine-Gordon models.Comment: 18 pages, LaTex. References added. A general product f(xvt)g(xvt)f(x-vt) \star g(x-vt) has been considered in the conclusion section . Version to appear in JHE

    The stability of the O(N) invariant fixed point in three dimensions

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    We study the stability of the O(N) fixed point in three dimensions under perturbations of the cubic type. We address this problem in the three cases N=2,3,4N=2,3,4 by using finite size scaling techniques and high precision Monte Carlo simulations. It is well know that there is a critical value 2<Nc<42<N_c<4 below which the O(N) fixed point is stable and above which the cubic fixed point becomes the stable one. While we cannot exclude that Nc<3N_c<3, as recently claimed by Kleinert and collaborators, our analysis strongly suggests that NcN_c coincides with 3.Comment: latex file of 18 pages plus three ps figure

    Electrical and Thermal Behavior of Copper-Epoxy Nanocomposites Prepared via Aqueous to Organic Phase Transfer Technique

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    The preparation, electrical, and thermal behaviors of copper-epoxy nanocomposites are described. Cetyltrimethylammonium bromide- (CTAB-) stabilized copper (Cu) particles were synthesized via phase transfer technique. Isopropanol (IPA), sodium borohydride (NaBH4), and toluene solution of diglycidyl ether of bisphenol A (DGEBA) were used as transferring, reducing agent, and the organic phase, respectively. The UV-Vis absorbance spectra of all the sols prepared indicate that the presence of Cu particles with the particles transfer efficiency is ≥97%. The amount, size, and size distribution of particles in the organosol were dependent on the content of organic solute in the organosol. The composites were obtained upon drying the organosols and these were then subjected to further studies on the curing, thermal, and electrical characteristic. The presence of Cu fillers does not significantly affect the completeness of the composite curing process and only slightly reduce the thermal stability of the composites that is >300◦C. The highest conductivity value of the composites obtained is 3.06 × 10−2 S cm−1

    Cognition-Enhancing Drugs: Can We Say No?

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    Normative analysis of cognition-enhancing drugs frequently weighs the liberty interests of drug users against egalitarian commitments to a level playing field. Yet those who would refuse to engage in neuroenhancement may well find their liberty to do so limited in a society where such drugs are widespread. To the extent that unvarnished emotional responses are world-disclosive, neurocosmetic practices also threaten to provide a form of faulty data to their users. This essay examines underappreciated liberty-based and epistemic rationales for regulating cognition-enhancing drugs

    Quantum group symmetry of the Quantum Hall effect on the non-flat surfaces

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    After showing that the magnetic translation operators are not the symmetries of the QHE on non-flat surfaces , we show that there exist another set of operators which leads to the quantum group symmetries for some of these surfaces . As a first example we show that the su(2)su(2) symmetry of the QHE on sphere leads to suq(2)su_q(2) algebra in the equator . We explain this result by a contraction of su(2)su(2) . Secondly , with the help of the symmetry operators of QHE on the Pioncare upper half plane , we will show that the ground state wave functions form a representation of the suq(2)su_q(2) algebra .Comment: 8 pages,latex,no figur
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