6,099 research outputs found

    Predicting the behaviour of non-circular, curved-in-plan retaining walls using the trial load method

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    The trial load method is a long established method to predict the behaviour, and design of arch dams. This paper presents the first implementation of this method to predict the behaviour of non-circular, curved-in-plan, deep excavations. The results of the method were compared to a curved excavation, observed in literature and results of models in PLAXIS 3D. The results show that the trial load method can be successfully used to predict the behaviour of curved walls, and provides insights on further research to validate its use more widely for design purposes and its potential to be applied to the design of typical (i.e. straight) retaining walls

    Alice falls into a black hole: Entanglement in non-inertial frames

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    Two observers determine the entanglement between two free bosonic modes by each detecting one of the modes and observing the correlations between their measurements. We show that a state which is maximally entangled in an inertial frame becomes less entangled if the observers are relatively accelerated. This phenomenon, which is a consequence of the Unruh effect, shows that entanglement is an observer-dependent quantity in non-inertial frames. In the high acceleration limit, our results can be applied to a non-accelerated observer falling into a black hole while the accelerated one barely escapes. If the observer escapes with infinite acceleration, the state's distillable entanglement vanishes.Comment: I.F-S published before with maiden name Fuentes-Guridi Replaced with published version. Phys. Rev. Lett. in pres

    Consequences of spontaneous reconnection at a two-dimensional non-force-free current layer

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    Magnetic neutral points, where the magnitude of the magnetic field vanishes locally, are potential locations for energy conversion in the solar corona. The fact that the magnetic field is identically zero at these points suggests that for the study of current sheet formation and of any subsequent resistive dissipation phase, a finite beta plasma should be considered, rather than neglecting the plasma pressure as has often been the case in the past. The rapid dissipation of a finite current layer in non-force-free equilibrium is investigated numerically, after the sudden onset of an anomalous resistivity. The aim of this study is to determine how the energy is redistributed during the initial diffusion phase, and what is the nature of the outward transmission of information and energy. The resistivity rapidly diffuses the current at the null point. The presence of a plasma pressure allows the vast majority of the free energy to be transferred into internal energy. Most of the converted energy is used in direct heating of the surrounding plasma, and only about 3% is converted into kinetic energy, causing a perturbation in the magnetic field and the plasma which propagates away from the null at the local fast magnetoacoustic speed. The propagating pulses show a complex structure due to the highly non-uniform initial state. It is shown that this perturbation carries no net current as it propagates away from the null. The fact that, under the assumptions taken in this paper, most of the magnetic energy released in the reconnection converts internal energy of the plasma, may be highly important for the chromospheric and coronal heating problem

    Berry Phase Quantum Thermometer

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    We show how Berry phase can be used to construct an ultra-high precision quantum thermometer. An important advantage of our scheme is that there is no need for the thermometer to acquire thermal equilibrium with the sample. This reduces measurement times and avoids precision limitations.Comment: Updated to published version. I. Fuentes previously published as I. Fuentes-Guridi and I. Fuentes-Schulle

    Consumer Confidence in the Food System, Media Coverage and Stock Prices of Food Companies: A Regression Analysis

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    A series of recent and serious food safety incidents have generated a national debate over the significant costs that they impose on various stakeholders - consumers, industry, or the government. This paper examines the impact of media coverage of food safety and defense issues on consumer confidence in food safety, and measures the response of stock prices of food companies to changes in consumer confidence. Results show that, increases in media coverage have a negative impact on consumer confidence, and that decreases in the levels of consumer confidence on food safety have a negative impact on stock prices of food companies, in particular for the larger firms. These findings confirm that the financial performance of food the industry is negatively affected by category-specific food safety events, and the effects of media coverage on consumer confidence in the safety of the food system.Agribusiness, Food Consumption/Nutrition/Food Safety,
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