3,810 research outputs found

    Accuracy Improvement of Real-Time Load-Pull Measurements

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    This paper describes a new procedure aimed to improve the effectiveness of real-time load-pull calibration. Loadpull measurement accuracy is strongly affected by calibration residual uncertainty. The novel methodology reduces this uncertainty contribution by means of error terms optimization. The proposed method has been tested with simulations and applied to actual measurement data. Considerable improvements have been achieve

    Transport efficiency of metachronal waves in 3d cilia arrays immersed in a two-phase flow

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    The present work reports the formation and the characterization of antipleptic and symplectic metachronal waves in 3D cilia arrays immersed in a two-fluid environment, with a viscosity ratio of 20. A coupled lattice-Boltzmann-Immersed-Boundary solver is used. The periciliary layer is confined between the epithelial surface and the mucus. Its thickness is chosen such that the tips of the cilia can penetrate the mucus. A purely hydrodynamical feedback of the fluid is taken into account and a coupling parameter α\alpha is introduced allowing the tuning of both the direction of the wave propagation, and the strength of the fluid feedback. A comparative study of both antipleptic and symplectic waves, mapping a cilia inter-spacing ranging from 1.67 up to 5 cilia length, is performed by imposing the metachrony. Antipleptic waves are found to systematically outperform sympletic waves. They are shown to be more efficient for transporting and mixing the fluids, while spending less energy than symplectic, random, or synchronized motions

    Social Network Capital and Academic Careers

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    Social Network Capital and Academic Careers: The Case of a College of Agriculture ABSTRACT The relationship between economic performance and various forms of capital anchors a significant portion of mainstream economic theory and applied economics. Human, physical and financial capital represent important factors in the production of goods and services. The label “capital” implies characteristics such as investment, accumulation, maintenance, depreciation, and transfer. Recently, social capital or social network capital (SNC) has received increased scholarly attention in the literature of sociology, business, and economics. Limited analysis, however, has been directed at the role of SNC in the academy. We hypothesize that academic success at the professorial level is determined by the stock of human (HC) and SNC and the value flows emerging from these stocks. We view SNC as a complement to HC, increasing the productivity of HC while holding all other factors constant. An analysis of SNC’s importance to academic career success should interest the academy as well as other large organizations (i.e. research laboratories, government agencies) with similar structures and incentive systems.Social capital, academic networks, human capital, Institutional and Behavioral Economics, Labor and Human Capital, Teaching/Communication/Extension/Profession,

    The accessibility produced by a local transit network

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    This research sets some accessibility indicators referred to a road intercity transit system for commuting users within a district. The aim is to make available some accessibility measure tools by which evaluate the effects, on this performance, of the actions designed for a local transit network

    Composite lacunary polynomials and the proof of a conjecture of Schinzel

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    Let g(x)g(x) be a fixed non-constant complex polynomial. It was conjectured by Schinzel that if g(h(x))g(h(x)) has boundedly many terms, then h(x)\in \C[x] must also have boundedly many terms. Solving an older conjecture raised by R\'enyi and by Erd\"os, Schinzel had proved this in the special cases g(x)=xdg(x)=x^d; however that method does not extend to the general case. Here we prove the full Schinzel's conjecture (actually in sharper form) by a completely different method. Simultaneously we establish an "algorithmic" parametric description of the general decomposition f(x)=g(h(x))f(x)=g(h(x)), where ff is a polynomial with a given number of terms and g,hg,h are arbitrary polynomials. As a corollary, this implies for instance that a polynomial with ll terms and given coefficients is non-trivially decomposable if and only if the degree-vector lies in the union of certain finitely many subgroups of Zl\Z^l.Comment: 9 page

    An immersed boundary-lattice Boltzmann method for single- and multi-component fluid flows

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    International audienceThe paper presents a numerical method to simulate single-and multi-component fluid flows around moving/deformable solid boundaries, based on the coupling of Immersed Boundary (IB) and Lattice Boltzmann (LB) methods. The fluid domain is simulated with LB method using the single relaxation time BGK model, in which an interparticle potential model is applied for multi-component fluid flows. The IB-related force is directly calculated with the interpolated definition of the fluid macroscopic velocity on the Lagrangian points that define the immersed solid boundary. The present IB-LB method can better ensure the no-slip solid boundary condition, thanks to an improved spreading operator. The proposed method is validated through several 2D/3D single-and multi-component fluid test cases with a particular emphasis on wetting conditions on solid wall. Finally, a 3D two-fluid application case is given to show the feasibility of modeling the fluid transport via a cluster of beating cilia

    Acceleration of hemiacetal cleavage through hydrogen bonding : a new synthetic catalyst with balanced conformational flexibility and preorganization

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    Hemiacetal cleavage catalyst 1 was designed, synthesized, and shown to be effective in promoting glycolaldehyde dimer dissociation and tetramethylglucose mutarotation
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