4,941 research outputs found

    Energetics of lipid bilayers with applications to deformations induced by inclusions

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    A new energy for the description of large deformations of lipid bilayers is formulated with mathematical rigor. This energy is derived by considering the smectic A liquid crystalline nature of lipid bilayers and the coupling between the deformations of the layers and their constituent lipid molecules. Analogies between smectic A liquid crystals, with an infinite number of layers, and lipid bilayers, with a finite number of layers, are further discussed. The novelty of the energy density is demonstrated by studying the large deformations of planar lipid bilayers induced by cylindrical inclusions. The results of this study are directly compared with the results obtained using May's theoretical framework [May, Eur. Biophys. J., 2000, 29, 17–28] in which small deformations are assumed. As expected, the proposed energy density predicts larger distortions of the lipid molecules and deformations of the lipid bilayers close to an inclusion

    Spin structure of spin-1/2 baryon and spinless meson production amplitudes in photo and hadronic reactions

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    The most general spin structures of the spin-1/2 baryon and spinless meson production operator for both photon and nucleon induced reactions are derived from the partial-wave expansions of these reaction amplitudes. The present method provides the coefficients multiplying each spin operator in terms of the partial-wave matrix elements. The result should be useful in studies of these reactions based on partial-wave analyses, especially, when spin observables are considered.Comment: RevTex 34 pages, revised versio

    A semi-Lagrangian scheme for the game pp-Laplacian via pp-averaging

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    We present and analyze an approximation scheme for the two-dimensional game pp-Laplacian in the framework of viscosity solutions. The approximation is based on a semi-Lagrangian scheme which exploits the idea of pp-averages. We study the properties of the scheme and prove that it converges, in particular cases, to the viscosity solution of the game pp-Laplacian. We also present a numerical implementation of the scheme for different values of pp; the numerical tests show that the scheme is accurate.Comment: 34 pages, 3 figures. To appear on Applied Numerical Mathematic

    SCINTILLA A European project for the development of scintillation detectors and new technologies for nuclear security

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    Europe monitors transits using radiation detectors to prevent illicit trafficking of nuclear materials. The SCINTILLA project aims to develop a toolbox of innovative technologies designed to address different usage cases. This article will review the scope, approach, results of the first benchmark campaign and future plans of the SCINTILLA project.Comment: To appear on the Proceedings of the 13th ICATPP Conference on Astroparticle, Particle, Space Physics and Detectors for Physics Applications, Villa Olmo (Como, Italy), 23--27 October, 2013, to be published by World Scientific (Singapore

    P-wave pi pi amplitude from dispersion relations

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    We solve the dispersion relation for the P-wave pi pi amplitude.We discuss the role of the left hand cut vs Castillejo-Dalitz-Dyson (CDD), pole contribution and compare the solution with a generic quark model description. We review the the generic properties of analytical partial wave scattering and production amplitudes and discuses their applicability and fits of experimental data.Comment: 10 pages, 7 figures, typos corrected, reference adde

    Photoproduction of the ω\omega meson on the proton at large momentum transfer

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    The differential cross section, dσ/dtd\sigma/dt for ω\omega meson exclusive photoproduction on the proton above the resonance region (2.6<W<2.92.6<W<2.9 GeV) was measured up to a momentum transfer t=5-t = 5 GeV2^2 using the CLAS detector at Jefferson Laboratory. The ω\omega channel was identified by detecting a proton and π+\pi^+ in the final state and using the missing mass technique. While the low momentum transfer region shows the typical diffractive pattern expected from Pomeron and Reggeon exchange, at large t-t the differential cross section has a flat behavior. This feature can be explained by introducing quark interchange processes in addition to the QCD-inspired two-gluon exchange.Comment: 5 pages, 5 figure

    PENERAPAN METODE DEMONSTRASI MELALUI KEGIATAN MELIPAT UNTUK MENINGKATKAN MOTORIK HALUS ANAK USIA 5-6 TAHUN

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    AbstractThis study aims to describe the application of the demonstration method through folding activities to improve fine motor skills for children aged 5- 6 years at Mulia Dharma Kindergarten, Pontianak. The research method is a descriptive method in the form of classroom action research. The subjects in the study were teachers of TK B class and early childhood in group B. The data collection techniques for this research were observation, interviews, and documentation. The results showed that: 1. Teacher planning, namely preparing research instruments and Daily Learning Implementation Plans in the application of the demonstration method through folding activities, there were ten children who had improved their fine motor skills. 2. The research was carried out in two cycles where each cycle consisted of two meetings. 3. The evaluation that the teacher uses is to use an assessment of the assignments and results of children's work in folding activities. 4. There was an improvement from both cycles by using the demonstration method through folding activities to improve the fine motor skills of group B children at Mulia Dharma Kindergarten Pontianak. The application of the demonstration method through folding activities to improve the fine motor skills of children aged 5-6 years at Mulia Dharma Kindergarten Pontianak has been carried out well.Keywords: Demonstration method, Fine motor, and Foldin
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