665 research outputs found

    Gender and sexuality: the discursive limits of 'equality' in higher education

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    This special issue sets out to investigate a number of areas of concern, regarding gender and sexuality, which are identifiable in the current British higher education environment. We argue that current dominant 'neoliberal' discourses, which emphasise the commodification of higher education in the UK, function to set limits upon 'equality'. While these discourses often suggest a widening of opportunities within higher education, with an emphasis upon unlimited individual freedom and choice, the lived experience can be rather different for women and sexual minorities. This issue explores the impact such discourses are having upon gender and sexuality identities and practices in the academy

    Field- and pressure-induced phases in Sr4_{4}Ru3_{3}O10_{10}: A spectroscopic investigation

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    We have investigated the magnetic-field- and pressure-induced structural and magnetic phases of the triple-layer ruthenate - Sr4_{4}Ru3_{3}O10_{10}. Magnetic-field-induced changes in the phonon spectra reveal dramatic spin-reorientation transitions and strong magneto-elastic coupling in this material. Additionally, pressure-dependent Raman measurements at different temperatures reveal an anomalous negative Gruneisen-parameter associated with the B1g_{1g} mode (\sim 380 cm1^{-1}) at low temperatures (T << 75K), which can be explained consistently with the field dependent Raman data.Comment: 5 pages, 4 figures final version published in PRL 96, 067004 (2006

    Magnetic Transformations in the Organic Conductor kappa-(BETS)2Mn[N(CN)2]3 at the Metal-Insulator Transition

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    A complex study of magnetic properties including dc magnetization, 1H NMR and magnetic torque measurements has been performed for the organic conductor kappa-(BETS)2Mn[N(CN)2]3 which undergoes a metal-insulator transition at T_MI~25K. NMR and the magnetization data indicate a transition in the manganese subsystem from paramagnetic to a frozen state at T_MI, which is, however, not a simple Neel type order. Further, a magnetic field induced transition resembling a spin flop has been detected in the torque measurements at temperatures below T_MI. This transition is most likely related to the spins of pi-electrons localized on the organic molecules BETS and coupled with the manganese 3d spins via exchange interaction.Comment: 6 pages, 5 Figures, 1 Table; Submitted to Phys.Rev.B (Nov.2010

    Large angle magnetization dynamics measured by time-resolved ferromagnetic resonance

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    A time-resolved ferromagnetic resonance technique was used to investigate the magnetization dynamics of a 10 nm thin Permalloy film. The experiment consisted of a sequence of magnetic field pulses at a repetition rate equal to the magnetic systems resonance frequency. We compared data obtained by this technique with conventional pulsed inductive microwave magnetometry. The results for damping and frequency response obtained by these two different methods coincide in the limit of a small angle excitation. However, when applying large amplitude field pulses, the magnetization had a non-linear response. We speculate that one possible cause of the nonlinearity is related to self-amplification of incoherence, known as the Suhl instabilities.Comment: 23 pages, 8 figures, submitted to PR

    PREDICTIONS OF WEAR AND TRANSMISSION ERRORS OF CYLINDRICAL WORM GEARS

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    ABSTRACT Transmission error (TE) is an important transmission parameter for precision worm gears. Modern cutting methods in conjunction with modern software allow manufacturers to deliver worm gear products of high accuracy to the highly competitive market. However, the initial shape of a bronze wheel tooth changes dramatically due to bedding-in and wear when gears mesh under load, and hence transmission characteristics change. A computer program is being developed to predict wear during bedding-in and constant wear rate stages for involute worm gears. A progressive wear over given number of tooth engagements is estimated using both the available experimental wear data and theoretical considerations. Being subtracted from an &quot;as-cut&quot; geometry, a new shape of worm wheel tooth surface can be predicted. The calculations can be executed iteratively for as many wear steps as necessary. The model takes load sharing and contact stress distribution into account to estimate the lubrication oil film thickness and wear intensity. Contact patterns, TE, load cycles and meshing stiffness are also modeled. A comparison between theoretical wear predictions and experimental wear data is made. Predictions of wear and transmission errors are useful for optimization of existing worm gear design and for development of worm gears of new designs. INTRODUCTION Wormwheels&apos; resistance to wear and pitting is mainly determined by their load capacit

    Thermally Activated Magnetization and Resistance Decay during Near Ambient Temperature Aging of Co Nanoflakes in a Confining Semi-metallic Environment

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    We report the observation of magnetic and resistive aging in a self assembled nanoparticle system produced in a multilayer Co/Sb sandwich. The aging decays are characterized by an initial slow decay followed by a more rapid decay in both the magnetization and resistance. The decays are large accounting for almost 70% of the magnetization and almost 40% of the resistance for samples deposited at 35 oC^oC. For samples deposited at 50 oC^oC the magnetization decay accounts for 50\sim 50% of the magnetization and 50% of the resistance. During the more rapid part of the decay, the concavity of the slope of the decay changes sign and this inflection point can be used to provide a characteristic time. The characteristic time is strongly and systematically temperature dependent, ranging from 1\sim1x102s10^2 s at 400K to 3\sim3x105s10^5 s at 320K in samples deposited at 35oC35 ^oC. Samples deposited at 50 oC^oC displayed a 7-8 fold increase in the characteristic time (compared to the 35oC35 ^oC samples) for a given aging temperature, indicating that this timescale may be tunable. Both the temperature scale and time scales are in potentially useful regimes. Pre-Aging, Scanning Tunneling Microscopy (STM) reveals that the Co forms in nanoscale flakes. During aging the nanoflakes melt and migrate into each other in an anisotropic fashion forming elongated Co nanowires. This aging behavior occurs within a confined environment of the enveloping Sb layers. The relationship between the characteristic time and aging temperature fits an Arrhenius law indicating activated dynamics

    Magnetization Reversal in Elongated Fe Nanoparticles

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    Magnetization reversal of individual, isolated high-aspect-ratio Fe nanoparticles with diameters comparable to the magnetic exchange length is studied by high-sensitivity submicron Hall magnetometry. For a Fe nanoparticle with diameter of 5 nm, the magnetization reversal is found to be an incoherent process with localized nucleation assisted by thermal activation, even though the particle has a single-domain static state. For a larger elongated Fe nanoparticle with a diameter greater than 10 nm, the inhomogeneous magnetic structure of the particle plays important role in the reversal process.Comment: 6 pages, 6 figures, to appear in Phys. Rev. B (2005
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