1,782 research outputs found

    Oxidation of Nickel in AlCl3-1-Butylpyridinium Chloride at Ambient Temperature

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    We have studied in detail the electrochemical reaction of nickel in several kinds of molar ratio-controlled molten salts consisting of AlCl(3) and 1-butylpyridinium chloride (BPC) at 40°C. We observed NiCl(2) as an oxidation product from nickel on the surface of the electrode in slightly acidic AlCl(3)/BPC salts with molar ratios of 1.05/1.0 and 1.1/1.0. However, in strongly acidic salt with the ratio of 1.5/1.0, NiCl(2) deposits on the electrode less than when in the above salts, and no NiCl(29) is observed in basic and neutral salts with the ratio of 1.0/1.0 or less AlCl(3) content. This suggests that [NiCl(4)](2−) ions form as the oxidation of nickel in such neutral and basic AlC(3)/BPC (salts)

    Deformation of Equilibrium Shape of a Vesicle Induced by Injected Flexible Polymers

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    Using field theoretic approach, we study equilibrium shape deformation of a vesicle induced by the presence of enclosed flexible polymers, which is a simple model of drug delivery system or endocytosis. To evaluate the total free energy of this system, it is necessary to calculate the bending elastic energy of the membrane, the conformation entropy of the polymers and their interactions. For this purpose, we combine phase field theory for the membrane and self-consistent field theory for the polymers. Simulations on this coupled model system for axiosymmetric shapes show a shape deformation of the vesicle induced by introducing polymers into it. We examined the dependence of the stability of the vesicle shape on the chain length of the polymers and the packing ratio of the vesicle. We present a simple model calculation that shows the relative stability of the prolate shape compared to the oblate shape.Comment: 5 pages, 3 figure

    Design and performance of the muon monitor for the T2K neutrino oscillation experiment

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    This article describes the design and performance of the muon monitor for the T2K (Tokaito-Kamioka) long baseline neutrino oscillation experiment. The muon monitor consists of two types of detector arrays: ionization chambers and silicon PIN photodiodes. It measures the intensity and profile of muons produced, along with neutrinos, in the decay of pions. The measurement is sensitive to the intensity and direction of the neutrino beam. The linearity and stability of the detectors were measured in beam tests to be within 2.4% and 1.5%, respectively. Based on the test results, the precision of the beam direction measured by the muon monitor is expected to be 0.25 mrad.Comment: 22 page

    Numerical computations of facetted pattern formation in snow crystal growth

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    Facetted growth of snow crystals leads to a rich diversity of forms, and exhibits a remarkable sixfold symmetry. Snow crystal structures result from diffusion limited crystal growth in the presence of anisotropic surface energy and anisotropic attachment kinetics. It is by now well understood that the morphological stability of ice crystals strongly depends on supersaturation, crystal size and temperature. Until very recently it was very difficult to perform numerical simulations of this highly anisotropic crystal growth. In particular, obtaining facet growth in combination with dendritic branching is a challenging task. We present numerical simulations of snow crystal growth in two and three space dimensions using a new computational method recently introduced by the authors. We present both qualitative and quantitative computations. In particular, a linear relationship between tip velocity and supersaturation is observed. The computations also suggest that surface energy effects, although small, have a larger effect on crystal growth than previously expected. We compute solid plates, solid prisms, hollow columns, needles, dendrites, capped columns and scrolls on plates. Although all these forms appear in nature, most of these forms are computed here for the first time in numerical simulations for a continuum model.Comment: 12 pages, 28 figure
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