3,628 research outputs found

    Evolution of quantum observables: from non-commutativity to commutativity

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    A fundamental aspect of the quantum-to-classical limit is the transition from a non- commutative algebra of observables to commutative one.However, this transition is not possible if we only consider unitary evolutions. One way to describe this transition is to consider the Gamow vectors, which introduce exponential decays in the evolution. In this paper, we give two mathematical models in which this transition happens in the infinite time limit. In the first one, we consider operators acting on the space of the Gamow vectors, which represent quantum resonances. In the second one, we use an algebraic formalism from scattering theory. We construct a non-commuting algebra which commutes in the infinite time limit.MINECO Grant MTM2014- 57129-C2-1-P. Junta de Castilla y Leon Grants BU229P18, VA137G18

    An Application of Cooperative Game Theory to Distributed Control

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    18th World CongressThe International Federation of Automatic ControlMilano (Italy) August 28 - September 2, 2011In this paper we propose to study the underlying properties of a given distributed control scheme in which a set of agents switch between different communication strategies that define which network links are used in order to regulate to the origin a set of unconstrained linear systems. The problems of how to decide the time-varying communication strategy, share the benefits/costs and detect which are the most critical links in the network are solved using tools from game theory. The proposed scheme is demonstrated through a simulation example

    Real-Time Fluids – Optimizing Grid-Based Methods

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    A fluid simulation suitable for use in real-time virtual environments running at interactive frame rates has the potential to greatly improve the quality of the virtual environments it is used in. To this end we present a method suitable for use in real-time grid-based fluid simulation that considerably reduces the amount of data being processed at each simulation step by removing unused cells from the simulation gri

    Antioxidants supplementation in elderly cardiovascular patients

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    Supplementation with antioxidants and its benefit-risk relationship have been largely discussed in the elderly population. We evaluated whether antioxidants supplementation improved the biochemical profile associated with oxidative metabolism in elderly cardiovascular patients. Patients (n = 112) received daily supplementation with α-TP 400 mg, beta-carotene 40 mg, and vitamin C 1000 mg for 2 months (treatment). Plasma concentrations of alpha-tocopherol (α-TP), β-carotene (βC), ubiquinol-10 (QH-10), glutathione, and thiobarbituric acid reactive substances (TBARS) were determined before and after treatment. Response to treatment was dependent on pretreatment α-TP and βC levels. Increase in α-TP and βC levels was observed only in patients with basal levels <18 μM for α-TP (P < 0.01) and <0.30 μM for βC (P < 0.02). Ubiquinol-10, glutathione, and TBARS were unaffected by treatment: QH-10 (+57%, F(1,110) = 3.611, P < 0.06, and N.S.), glutathione (+21%, F(1,110) = 2.92, P < 0.09, and N.S.), and TBARS (-29%, F(1,110) = 2.26, P < 0.14, and N.S.). Treatment reduced oxidative metabolism: 5.3% versus 14.6% basal value (F(1,110) = 9.21, P < 0.0003). Basal TBARS/α-TP ratio was higher in smokers compared to nonsmokers: 0.11 ± 0.02 versus 0.06 ± 0.01 (F(32,80) = 1.63, P < 0.04). Response to antioxidant supplementation was dependent on basal plasma levels of α- TP and βC. Smoking status was strongly associated with atherosclerotic cardiovascular disease and high TBARS/α-TP ratio (lipid peroxidation).Fil: Otero Losada, Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); Argentina;Fil: Vila, Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); Argentina;Fil: Azzato, F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); Argentina;Fil: Milei, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); Argentina

    Ontwikkeling snelle meetmethode ter bepaling van ammoniakemissiereductie van vloergebonden maatregelen = Development of a fast measurement method for the determination of ammonia emission reduction from floor related measures

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    This report describes different methods for determination of the effect of different floor types on (ammonia) emission. One method, the box method, has been further evaluated
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