1,166 research outputs found

    A Fixpoint Semantics of Event Systems with and without Fairness Assumptions

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    We present a fixpoint semantics of event systems. The semantics is presented in a general framework without concerns of fairness. Soundness and completeness of rules for deriving "leads-to" properties are proved in this general framework. The general framework is instantiated to minimal progress and weak fairness assumptions and similar results are obtained. We show the power of these results by deriving sufficient conditions for "leads-to" under minimal progress proving soundness of proof obligations without reasoning over state-traces

    Improved bounds on heavy quark electric dipole moments

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    New bounds on the electric dipole moment (EDM) of charm and bottom quarks are derived using the stringent limits on their chromo-EDMs. The new limits, ∣dc∣<1.5×10−21 e cm|d_c|<1.5\times10^{-21}\:e\,\text{cm} and ∣db∣<1.2×10−20 e cm|d_b|< 1.2\times 10^{-20}\:e\,\text{cm}, improve the previous ones by about three orders of magnitude. These indirect bounds have implications for different models of new physics, including two-Higgs-doublet, leptoquarks, and supersymmetry models.Comment: 5 pages, 4 figure

    PASSENGER MOBILITY AND CLIMATE CONSTRAINTS: ANALYSING ADAPTIVE STRATEGIES

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    Today, numerous works conclude that transport seems to be completely coupled to economic growth. Therefore, as a direct consequence of economic development, transport sits today as one of the major final energy consumers and one of the most important sources of carbon dioxide emissions. Furthermore, in the absence of major technological change, this unsustainable situation will most undoubtedly get worse in the future. In this paper we analyze what different types of public policies aiming at sharp reductions in GHG emissions imply on passenger transport and how they can be linked to new behavior patterns affecting time use and consumption. For this, we use the TILT (Transport Issues in the Long Term) model's core microeconomic choice model IT-UP (Integrated Tools for Utility-based Planning). Through this analysis, we explain the interest of adaptive strategies for GHG mitigation.Greenhouse gas, long term, scenario, transport, sustainable development.

    Planning for resilience in urban transport.

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    This paper develops the idea of taking into account the systemic effects of public policies for sustainable transport in long-term scenarios. A comprehensive assessment of these effects is a particularly important factor in identifying potential unbalancing elements and planning for resilience to the effects of mitigation policies in view of increasing acceptance to different measures on which GHG reductions depend.Modelling, Greenhouse gas, Coupling, Scenarios, 2050 horizon, mitigation, adaptation, multimodality, decoupling.

    Synthesis of iron oxide nanoparticles in a counterflow diffusion flame reactor

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    A Counterflow Diffusion Flame (CDF) reactor was used to produce iron oxide nanoparticles. The experimental work was performed to study synthesis conditions and characterize the iron oxide nanoparticles. The parameters studied are those that control the flame structure, namely, gas flow rates and vacuum; other parameters include the precursor volume flow rate, and the relative location and temperature of the collecting probe inside the flame. Hexagonal nanoparticles were the most commonly observed shape. Hexagonal-shaped nanoparticles are mainly formed under stoichiometric conditions and with a high temperature profile in the flame. Cubic nanoparticles were also observed. The main parameter for the formation of cubic-shaped nanoparticles was found to be the equivalence ratio. A minimum value of less than one percentage of cubic nanoparticles was observed at equivalence ratios ranging between 0.7488 and 0.9283. The main effect on particle size was observed to be from the hydrogen flow rate, which was found that the higher the hydrogen flow rate is, the smaller the average nanoparticle size. A secondary minor effect was observed from variations of vacuum flow rate. This effect could be associated with changes in the total mass or volumetric flow rate balance. Adjusting Nâ‚‚ in Hâ‚‚ stream allowed the synthesis of samples with approximately 95% hexagonal nanoparticles without agglomerates --Abstract, page iii

    Monte Carlo simulation with fixed steplength for diffusion processes in nonhomogeneous media

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    Monte Carlo simulation is one of the most important tools in the study of diffusion processes. For constant diffusion coefficients, an appropriate Gaussian distribution of particle's steplengths can generate exact results, when compared with integration of the diffusion equation. It is important to notice that the same method is completely erroneous when applied to non-homogeneous diffusion coefficients. A simple alternative, jumping at fixed steplengths with appropriate transition probabilities, produces correct results. Here, a model for diffusion of calcium ions in the neuromuscular junction of the crayfish is used as a test to compare Monte Carlo simulation with fixed and Gaussian steplength.Fil: Ruiz Barlett, María Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Hoyuelos, Miguel Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Martin, Hector Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin
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