97 research outputs found

    Partial anomalous pulmonary venous return associated with vascular anomalies of the aorta: multidetector computed tomography findings

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    Partial anomalous pulmonary venous return (PAPVR) is a congenital anomaly that involves drainage of one to three pulmonary veins directly into the right heart or systemic venous system, creating a partial left-to-right shunt. This drainage is associated with cardiac abnormalities such as mitral stenosis and pulmonary stenosis, patent ductus arteriosus, and atrial septal defects. We report a case of PAPVR associated with vascular anomalies of the aorta by multidetector computed tomography in an adult female patient

    Gas generator pressure control in throttleable ducted rockets: A classical and adaptive control approach

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    This paper describes the control of gas generator pressure in throttleable ducted rockets using nonlinear adaptive control as well as classical control approaches. Simulation results using the full nonlinear and time-varying dynamics of the gas generator are reported in both classical controller and adaptive controller cases. "Closed-loop Reference Model" structure is used together with the adaptive controller to improve transient response. Controllers are simulated to test their robustness by introducing uncertinities, disturbances and noise to the system. Cold Air Test Plant (CATP) is used as the test facility to compare the controllers and validate the results from simulations. Moreover, damping effect of CRM to oscillations in adaptive controller case is observed in CATP tests. © 2015 American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved

    On the capacity of printed planar rectangular patch antenna arrays in the MIMO channel: Analysis and measurements

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    Printed arrays of rectangular patch antennas are analyzed in terms of their MIMO performance using a full-wave channel model. These antennas are designed and manufactured in various array configurations, and their MIMO performance is measured in an indoor environment. Good agreement is achieved between the measurements and simulations performed using the full-wave channel model. Effects on the MIMO capacity of the mutual coupling and the electrical properties of the printed patches, such as the relative permittivity and thickness of the dielectric material, are explored. © 2006 IEEE

    Particle swarm optimization of dipole arrays for superior MIMO capacity

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    The particle swarm optimization (PSO) technique is employed to design MIMO arrays for superior capacity. A channel model based on the method of moments solution of the electric field integral equation is utilized with PSO for arrays of dipole elements. Freestanding and printed dipole arrays are analyzed and optimized. Their adaptive performance in the MIMO channel is compared. Numerical results in the form of mean capacity, including comparisons with genetic algorithm results and measurements, are given. © 2008 Wiley Periodicals, Inc

    Optimization of linear wire antenna arrays to increase MIMO capacity using swarm intelligence

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    Free standing linear arrays (FSLA) are analyzed and optimized to increase MIMO capacity. A MIMO channel model based on electric fields is used. The effects of mutual interactions among the array elements are included into the channel matrix using method of moments (MoM) based full-wave solvers. A tool to design an antenna array of superior MIMO capacity for any specified volume is developed. Particle swarm optimization is used as the main engine for the optimization tasks of the tool. Uniform linear arrays, uniform circular arrays and non-uniform arrays are analyzed and compared in terms of their channel capacity

    Constraint on compactification scale via recently observed baryonic ΛbΛ+\Lambda_b\rightarrow \Lambda \ell^+ \ell^- channel and analysis of the ΣbΣ+\Sigma_b \rightarrow \Sigma \ell^+ \ell^- transition in SM and UED scenario

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    We obtain a lower limit on the compactification scale of extra dimension via comparison of the branching ratio in the baryonic ΛbΛμ+μ\Lambda_b\rightarrow \Lambda \mu^+ \mu^- decay channel recently measured by CDF collaboration and our previous theoretical study. We also use the newly available form factors calculated via light cone QCD sum rules in full theory to analyze the flavour changing neutral current process of the ΣbΣ+\Sigma_b \rightarrow \Sigma \ell^+ \ell^- in universal extra dimension scenario in the presence of a single extra compact dimension. We calculate various physical quantities like branching ratio, forward-backward asymmetry, baryon polarizations and double lepton polarization asymmetries defining the decay channel under consideration. We also compare the obtained predictions with those of the standard model.Comment: 32 Pages, 27 Figures and one Tabl

    Feasibility studies for the measurement of time-like proton electromagnetic form factors from p¯ p→ μ+μ- at P ¯ ANDA at FAIR

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    This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, | GE| and | GM| , using the p¯ p→ μ+μ- reaction at P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is p¯ p→ π+π-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented

    PANDA Phase One - PANDA collaboration

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    The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or P¯ANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton–nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper
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