816 research outputs found

    Ridge Production in High-Multiplicity Hadronic Ultra-Peripheral Proton-Proton Collisions

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    An unexpected result at the RHIC and the LHC is the observation that high-multiplicity hadronic events in heavy-ion and proton-proton collisions are distributed as two "ridges", approximately flat in rapidity and opposite in azimuthal angle. We propose that the origin of these events is due to the inelastic collisions of aligned gluonic flux tubes that underly the color confinement of the quarks in each proton. We predict that high-multiplicity hadronic ridges will also be produced in the high energy photon-photon collisions accessible at the LHC in ultra-peripheral proton-proton collisions or at a high energy electron-positron collider. We also note the orientation of the flux tubes between the quark and antiquark of each high energy photon will be correlated with the plane of the scattered proton or lepton. Thus hadron production and ridge formation can be controlled in a novel way at the LHC by observing the azimuthal correlations of the scattering planes of the ultra-peripheral protons with the orientation of the produced ridges. Photon-photon collisions can thus illuminate the fundamental physics underlying the ridge effect and the physics of color confinement in QCD.Comment: Presented by SJB at Photon 2017: The International Conference on the Structure and the Interactions of the Photon and the International Workshop on Photon-Photon Collisions. CERN, May 22-26, 2017. References adde

    Cognitive ability experiment with photosensitive organic molecular thin films

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    We present an optical experiment which permits to evaluate the information exchange necessary to self-induce cooperatively a well-organized pattern in a randomly activated molecular assembly. A low-power coherent beam carrying polarization and wavelength information is used to organize a surface relief grating on a photochromic polymer thin film which is photo-activated by a powerful incoherent beam. We demonstrate experimentally that less than 1% of the molecules possessing information cooperatively transmit it to the entire photo-activated polymer film.Comment: 16 pages, 4 figure

    Homomorphisms of quantum groups

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    In this article, we study several equivalent notions of homomorphism between locally compact quantum groups compatible with duality. In particular, we show that our homomorphisms are equivalent to functors between the respective categories of coactions. We lift the reduced bicharacter to universal quantum groups for any locally compact quantum group defined by a modular multiplicative unitary, without assuming Haar weights. We work in the general setting of modular multiplicative unitaries

    Control of Dynamic Systems via Neural Networks

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    This report is devoted to the problem of controlling a class of linear time-invariant dynamic systems via controllers based on additive neural network models. In particular, the tracking and stabilization problems are considered. First, we show how to transform the problem of tracking a reference signal by a control system into the stabilization problem. Then, some concepts from the variable structure control theory are utilized to construct stabilizing controllers. In order to facilitate the stability analysis of the closed-loop systems we employ a special state space transformation. This transformation allows us also to reveal connections between the proposed controllers and the additive neural network models

    The Role of Biosurgical Hemostatic Sealants in Cardiac Surgery

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    The focus on superb quality and value of medical and surgical care has become a cornerstone of modern clinical practice. Within the realm of cardiothoracic surgery, quality is synonymous with technically excellent, safely conducted operative procedure followed by an uneventful patient recovery and follow-up. Critical to this process of clinical value creation is meticulous attention to all aspects of every step along the management continuum. From surgical quality improvement perspective, the reduction in blood loss and thus minimization of blood/blood product transfusions are of critical importance. This chapter focuses on the role of biosurgicals as useful adjuncts to achieving the ultimate goal of uneventful cardiac procedure and thus set the patient’s clinical course for optimal postoperative recovery and long-term well-being

    Thermalization vs. Isotropization & Azimuthal Fluctuations

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    Hydrodynamic description requires a local thermodynamic equilibrium of the system under study but an approximate hydrodynamic behaviour is already manifested when a momentum distribution of liquid components is not of equilibrium form but merely isotropic. While the process of equilibration is relatively slow, the parton system becomes isotropic rather fast due to the plasma instabilities. Azimuthal fluctuations observed in relativistic heavy-ion collisions are argued to distinguish between a fully equilibrated and only isotropic parton system produced in the collision early stage.Comment: 12 pages, presented at `Correlations and Fluctuations in Relativistic Nuclear Collisions', MIT, April 05, minor correction

    Avoiding Fire in the Operating Suite: An Intersection of Prevention and Common Sense

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    The operating room (OR) is a complex environment that involves large teams and multiple competing priorities, dynamically interacting throughout the entire course of a surgical procedure. The simultaneous presence of flammable substances, volatile gases, and the frequent use of electrical current results in a potentially dangerous combination. Operating room fire (ORF) is a rare but potentially devastating occurrence. To prevent this “never event”, it is critical for institutions to establish and follow proper fire safety protocols. Adherence to proven prevention strategies and awareness of associated risk factors will help reduce the incidence of this dreaded safety event. When ORF does occur despite strict adherence to established safety protocols, the entire OR team should know the steps required to contain and extinguish the fire as well as essential measures to minimize or avoid thermal injury. If injury does occur, it is important to recognize and treat it promptly. Appropriate and honest disclosure to all injured persons and their families should be made without delay. As with all serious patient safety events, regulatory reporting and root cause determinations must take place in accordance with applicable laws and regulations. The goal of patient safety champions at each institution should be the attainment of zero incidence of ORF
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