589 research outputs found

    Two-component Bose gases with one-body and two-body couplings

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    We study the competition between one-body and two-body couplings in weakly-interacting two-component Bose gases, in particular as regards field correlations. We derive the meanfield theory for both ground state and low-energy pair excitations in the general case where both one-body and two-body couplings are position-dependent and the fluid is subjected to a state-dependent trapping potential. General formulas for phase and density correlations are also derived. Focusing on the case of homogeneous systems, we discuss the pair-excitation spectrum and the corresponding excitation modes, and use them to calculate correlation functions, including both quantum and thermal fluctuation terms. We show that the relative phase of the two components is imposed by that of the one-body coupling, while its fluctuations are determined by the modulus of the one-body coupling and by the two-body coupling. One-body coupling and repulsive two-body coupling cooperate to suppress relative-phase fluctuations, while attractive two-body coupling tends to enhance them. Further applications of the formalism presented here and extensions of our work are also discussed.Comment: published versio

    Entanglement entropy for the long range Ising chain

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    We consider the Ising model in a transverse field with long-range antiferromagnetic interactions that decay as a power law with their distance. We study both the phase diagram and the entanglement properties as a function of the exponent of the interaction. The phase diagram can be used as a guide for future experiments with trapped ions. We find two gapped phases, one dominated by the transverse field, exhibiting quasi long range order, and one dominated by the long range interaction, with long range N\'eel ordered ground states. We determine the location of the quantum critical points separating those two phases. We determine their critical exponents and central-charges. In the phase with quasi long range order the ground states exhibit exotic corrections to the area law for the entanglement entropy coexisting with gapped entanglement spectra.Comment: 5 pages, all comments welcom

    Mobile robotic teleguide based on video images

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    “This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.” DOI: 10.1109/MRA.2008.929927Peer reviewe

    Indonesia in the 21st Century: Environment at the Crossroads

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    This paper aims to look at Indonesia's state of the environment at the end of the second 25 year Long Term Plan (Pembangunan Jangka Panjang Kedua -PJPT II), and also aims to signal a warning for Indonesia to put things in order and not to carry on with "business as usual". The "warning" stems from the concept of the Precautionary Principle which focuses on a worst case scenario and from there makes three appeals -the need to halt pollution in advance of concrete knowledge about its impacts, the need to take responsibility for pollution that is occurring, and like this paper itself, appeals to the idea that "common sense" must prevail if development is to be sustainable

    Extracorporeal life support for primary graft dysfunction after heart transplantation

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    OBJECTIVES Survival after heart transplantation is steadily improving but primary graft dysfunction (PGD) is still a leading cause of death. Medical management seems useful in mild or moderate PGD, whereas extracorporeal life support (ECLS) could be suggested for severe PGD refractory to conventional treatment. Our aim is to present the results of ECLS for PGD after heart transplantation at a single-centre experience. METHODS We performed an observational analysis of our local database. According to the International Society for Heart and Lung Transplantation classification, patients were divided into a left and biventricular failure (PGD-LV) or isolated right ventricular failure (PGD-RV) group. The primary end point was survival to hospital discharge. RESULTS Between January 2010 and December 2016, 38 patients presented with PGD (PGD-LV n = 22, 58%; PGD-RV n = 16, 42%) requiring ECLS support. The mean age was 50.8 ± 12.4 years and 79% were males. Baseline characteristics were comparable between the 2 groups. PGD-LV patients displayed a significantly higher mortality rate on ECLS support as opposed to PGD-RV patients (46% vs 13%, P = 0.033). The rate of complications during ECLS support was comparable between the 2 groups. Twenty-three (61%) patients were successfully weaned from ECLS (PGD-LV = 50% vs PGD-RV = 75%, P = 0.111) after a mean support of 9.0 ± 6.4 days. Seventeen (45%) patients survived to hospital discharge (PGD-LV = 41% vs PGD-RV = 50%, P = 0.410). CONCLUSIONS In case of severe PGD with various manifestations of ventricular failure refractory to conventional treatment, ECLS can be considered as a feasible option with satisfactory survival in this critically ill population
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