66,956 research outputs found

    Exceptional sets for Diophantine inequalities

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    We apply Freeman's variant of the Davenport-Heilbronn method to investigate the exceptional set of real numbers not close to some value of a given real diagonal form at an integral argument. Under appropriate conditions, we show that the exceptional set in the interval [-N,N] has measure O(N^{1-c}), for a positive number c

    Nonlinear gyrofluid computation of edge localised ideal ballooning modes

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    Three dimensional electromagnetic gyrofluid simulations of the ideal ballooning mode blowout scenario for tokamak edge localized modes (ELMs) are presented. Special emphasis is placed on energetic diagnosis, examining changes in the growth rate in the linear, overshoot, and decay phases. The saturation process is energy transfer to self generated edge turbulence which exhibits an ion temperature gradient (ITG) mode structure. Convergence in the decay phase is found only if the spectrum reaches the ion gyroradius. The equilibrium is a self consistent background whose evolution is taken into account. Approximately two thirds of the total energy in the edge layer is liberated in the blowout. Parameter dependence with respect to plasma pressure and the ion gyroradius is studied. Despite the violent nature of the short-lived process, the transition to nonlinearity is very similar to that found in generic tokamak edge turbulence.Comment: The following article has been submitted to Physics of Plasmas. After it is published, it will be found at http://pop.aip.org

    Design definition of a mechanical capacitor

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    A design study and analyses of a 10 kW-hr, 15 kW mechanical capacitor system was studied. It was determined that magnetically supported wheels constructed of advanced composites have the potential for high energy density and high power density. Structural concepts are analyzed that yield the highest energy density of any structural design yet reported. Particular attention was paid to the problem of 'friction' caused by magnetic and I to the second power R losses in the suspension and motor-generator subsystems, and low design friction levels have been achieved. The potentially long shelf life of this system, and the absence of wearing parts, provide superior performance over conventional flywheels supported with mechanical bearings. Costs and economies of energy storage wheels were reviewed briefly

    Quantifying Finite Temperature Effects in Atom Chip Interferometry of Bose-Einstein Condensates

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    We quantify the effect of phase fluctuations on atom chip interferometry of Bose-Einstein condensates. At very low temperatures, we observe small phase fluctuations, created by mean-field depletion, and a resonant production of vortices when the two clouds are initially in anti-phase. At higher temperatures, we show that the thermal occupation of Bogoliubov modes makes vortex production vary smoothly with the initial relative phase difference between the two atom clouds. We also propose a technique to observe vortex formation directly by creating a weak link between the two clouds. The position and direction of circulation of the vortices is subsequently revealed by kinks in the interference fringes produced when the two clouds expand into one another. This procedure may be exploited for precise force measurement or motion detection.Comment: 7 pages, 5 figure

    Implementing Care Aims in an integrated team

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    Care Aims is increasingly being used as a model of care within NHS services, particularly by allied health professionals. This article reports the findings of a pilot study exploring the impact of implementing Care Aims in an integrated community health team. It describes the main findings, and discusses the factors that appeared to impact on the implementation and use of the Care Aims approach in these teams. The model has been traditionally used in uni-professional teams rather than integrated teams. This case study suggests Care Aims has potential to support integrated team working. In this study, clinicians perceived Care Aims was a model that could improve care for patients, support professionals working together and support self-management. However, it is unclear whether it was Care Aims itself or the training and discussion that took place that enabled this team to develop and agree more consistent working practices. Similar to previous studies, this study has shown how team and professional culture can influence how team members work together and provide care in an integrated way. Team and professional cultures are also shown to influence how team members approach and embrace that change. As such, Care Aims may be more challenging to some staff groups to implement
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