986 research outputs found

    Nature of fault planes in solid neutron star matter

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    The properties of tectonic earthquake sources are compared with those deduced here for fault planes in solid neutron-star matter. The conclusion that neutron-star matter cannot exhibit brittle fracture at any temperature or magnetic field is significant for current theories of pulsar glitches, and of the anomalous X-ray pulsars and soft-gamma repeaters.Comment: 5 AAS LaTeX pages 1 eps figur

    Tricritical Phenomena at the Cerium γα\gamma \to \alpha Transition

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    The γα\gamma \to \alpha isostructural transition in the Ce0.9x_{0.9-x}Lax_xTh0.1_{0.1} system is measured as a function of La alloying using specific heat, magnetic susceptibility, resistivity, thermal expansivity/striction measurements. A line of discontinuous transitions, as indicated by the change in volume, decreases exponentially from 118 K to close to zero with increasing La doping and the transition changes from being first-order to continuous at a critical concentration 0.10xc0.140.10 \leq x_c \leq 0.14. At the tricritical point, the coefficient of the linear TT term in the specific heat γ\gamma and the magnetic susceptibility start to increase rapidly near xx = 0.14 and gradually approaches large values at xx=0.35 signifying that a heavy Fermi-liquid state evolves at large doping. Near xcx_c, the Wilson ratio, RWR_W, has a value of 3.0, signifying the presence of magnetic fluctuations. Also, the low-temperature resistivity shows that the character of the low-temperature Fermi-liquid is changing

    On the correlation between fragility and stretching in glassforming liquids

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    We study the pressure and temperature dependences of the dielectric relaxation of two molecular glassforming liquids, dibutyl phtalate and m-toluidine. We focus on two characteristics of the slowing down of relaxation, the fragility associated with the temperature dependence and the stretching characterizing the relaxation function. We combine our data with data from the literature to revisit the proposed correlation between these two quantities. We do this in light of constraints that we suggest to put on the search for empirical correlations among properties of glassformers. In particular, argue that a meaningful correlation is to be looked for between stretching and isochoric fragility, as both seem to be constant under isochronic conditions and thereby reflect the intrinsic effect of temperature

    Origin of complex crystal structures of elements at pressure

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    We present a unifying theory for the observed complex structures of the sp-bonded elements under pressure based on nearly free electron picture (NFE). In the intermediate pressure regime the dominant contribution to crystal structure arises from Fermi-surface Brillouin zone (FSBZ) interactions - structures which allow this are favoured. This simple theory explains the observed crystal structures, transport properties, the evolution of internal and unit cell parameters with pressure. We illustrate it with experimental data for these elements and ab initio calculation for Li.Comment: 4 pages 5 figure

    Positive-Operator-Valued Time Observable in Quantum Mechanics

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    We examine the longstanding problem of introducing a time observable in Quantum Mechanics; using the formalism of positive-operator-valued measures we show how to define such an observable in a natural way and we discuss some consequences.Comment: 13 pages, LaTeX, no figures. Some minor changes, expanded the bibliography (now it is bigger than the one in the published version), changed the title and the style for publication on the International Journal of Theoretical Physic

    Density scaling and quasiuniversality of flow-event statistics for athermal plastic flows

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    Athermal plastic flows were simulated for the Kob-Andersen binary Lennard-Jones system and its repulsive version in which the sign of the attractive terms is changed to a plus. Properties evaluated from simulations at different densities include the distributions of energy drops, stress drops, and strain intervals between the flow events. By reference to hidden scale invariance we show that simulations at a single density in conjunction with an equilibrium-liquid simulation at the same density allows one to predict the plastic flow-event properties at other densities. We furthermore demonstrate quasiuniversality of the flow-event statistics

    Braneworld reheating in the bulk inflaton model

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    In the context of the braneworld inflation driven by a bulk scalar field, we study the energy dissipation from the bulk scalar field into the matter on the brane in order to understand the reheating after inflation. Deriving the late-time behavior of the bulk field with dissipation by using the Green's function method, we give a rigorous justification of the statement that the standard reheating process is reproduced in this bulk inflaton model as long as the Hubble parameter on the brane and the mass of the bulk scalar field are much smaller than the 5-dimensional inverse curvature scale. Our result supports the idea that the brane inflation model caused by a bulk scalar field is expected to be a viable alternative scenario of the early universe.Comment: 5 pages, no figures, final version to be published in PR

    On Brane World Cosmological Perturbations

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    We discuss the scalar cosmological perturbations in a 3-brane world with a 5D bulk. We first show explicitly how the effective perturbed Einstein's equations on the brane (involving the Weyl fluid) are encoded into Mukohyama's master equation. We give the relation between Mukohyama's master variable and the perturbations of the Weyl fluid, we also discuss the relation between the former and the perturbations of matter and induced metric on the brane. We show that one can obtain a boundary condition on the brane for the master equation solely expressible in term of the master variable, in the case of a perfect fluid with adiabatic perturbations on a Randall-Sundrum (RS) or Dvali-Gabadadze-Porrati (DGP) brane. This provides an easy way to solve numerically for the evolution of the perturbations as well as should shed light on the various approximations done in the literature to deal with the Weyl degrees of freedom.Comment: 36 pages, 1 figur

    Telehealth competencies for allied health professionals: A scoping review

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    Introduction Telehealth has become one of the main methods of delivering allied health professional services world-wide, yet many professionals do not have sufficient training to deliver high-quality telehealth services. This review aims to identify what competencies allied health professionals require for effective telehealth service delivery. Methods This scoping review used the Population Concept Context framework and searched the following databases: MEDLINE, CINAHL, PsychInfo, Cochrane, EMBASE, Web of Science, PEDro, United Kingdom Health Forum, WHO, Health Education England, and all UK and Australian AHP professional bodies. Results A total of 37 articles were included out of 92,525 identified by the literature search. Competencies were related to two areas: (1) delivery of the telehealth consultation and (2) service management of telehealth consultations. The first area included the following competency themes: clinical reasoning, communication, effectively using technology, person-centred care, practice-based assessment and intervention knowledge/behaviour/skills, privacy, security, and patient safety, professionalism, and setting up the technical environment. The second area included the following competency themes: digital infrastructure, informing practice, and management. Although findings emphasised the importance of telehealth competencies, none have been implemented within education. One-third of the articles were from the discipline of psychology. Conclusion This is the first scoping review to combine telehealth competencies reported across allied health disciplines. Although there were a vast range of competencies, they need implementation into teaching and learning to be practically useful. Most competencies were from psychology, but potentially applicable for other allied health professionals. A shared and adaptable standard for telehealth competencies would be useful to ensure high-quality practice across all allied health professionals. </jats:sec

    The effect of transmucosal 0.2mg/kg Midazolam premedication on dental anxiety, anaesthetic induction and psychological morbidity in children undergoing general anaesthesia for tooth extraction

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    &lt;b&gt;Background:&lt;/b&gt; The project aims were to evaluate the benefit of transmucosal Midazolam 0.2mg/kg pre-medication on anxiety, induction behaviour and psychological morbidity in children undergoing general anaesthesia (GA) extractions. &lt;b&gt;Method:&lt;/b&gt; 179 children aged 5-10 years (mean 6.53 years) participated in this randomised, double blind, placebo controlled trial. Ninety children had Midazolam placed in the buccal pouch. Dental anxiety was recorded pre operatively and 48 hours later using a child reported MCDAS-FIS scale. Behaviour at anaesthetic induction was recorded and psychological morbidity was scored by the parent using the Rutter Scale pre-operatively and again one-week later. Subsequent dental attendance was recorded at one, three and six months after GA. &lt;b&gt;Results:&lt;/b&gt; Whilst levels of mental anxiety did not reduce overall, the most anxious patients demonstrated a reduction in anxiety after receiving midazolam premedicationmay (p=0.01). Neither induction behaviour nor psychological morbidity improved. Irrespective of group, parents reported less hyperactive (p= 0.002) and more prosocial behaviour (p=0.002) after the procedure:;, older children improved most (p=0.048), Post GA Dental attendance was poor and unrelated to after the procedure and unaffected by premedication. &lt;b&gt;Conclusion:&lt;/b&gt; 0.2mg/kg buccal Midazolam provided some evidence for reducing anxiety in the most dentally anxious patients. However, induction behaviour, psychological morbidity and subsequent dental attendance were not found to alter between the premedication groups
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