103 research outputs found

    Impact of 3-Cyanopropionic Acid Methyl Ester on the Electrochemical Performance of ZnMnâ‚‚Oâ‚„ as Negative Electrode for Li-Ion Batteries

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    Due to their high theoretical capacity, transition metal oxide compounds are promising electrode materials for lithium-ion batteries. However, one drawback is associated with relevant capacity fluctuations during cycling, widely observed in the literature. Such strong capacity variation can result in practical problems when positive and negative electrode materials have to be matched in a full cell. Herein, the study of ZnMn2O4 (ZMO) in a nonconventional electrolyte based on 3-cyanopropionic acid methyl ester (CPAME) solvent and LiPF6 salt is reported for the first time. Although ZMO in LiPF6/CPAME electrolyte displays a dramatic capacity decay during the first cycles, it shows promising cycling ability and a suppressed capacity fluctuation when vinylene carbonate (VC) is used as an additive to the CPAME-based electrolyte. To understand the nature of the solid electrolyte interphase (SEI), the electrochemical study is correlated to ex situ X-ray photoelectron spectroscopy (XPS)

    Renormalisation group corrections to neutrino mixing sum rules

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    Neutrino mixing sum rules are common to a large class of models based on the (discrete) symmetry approach to lepton flavour. In this approach the neutrino mixing matrix UU is assumed to have an underlying approximate symmetry form \tildeU_\nu, which is dictated by, or associated with, the employed (discrete) symmetry. In such a setup the cosine of the Dirac CP-violating phase δ\delta can be related to the three neutrino mixing angles in terms of a sum rule which depends on the symmetry form of \tildeU_\nu. We consider five extensively discussed possible symmetry forms of \tildeU_\nu: i) bimaximal (BM) and ii) tri-bimaximal (TBM) forms, the forms corresponding to iii) golden ratio type A (GRA) mixing, iv) golden ratio type B (GRB) mixing, and v) hexagonal (HG) mixing. For each of these forms we investigate the renormalisation group corrections to the sum rule predictions for δ\delta in the cases of neutrino Majorana mass term generated by the Weinberg (dimension 5) operator added to i) the Standard Model, and ii) the minimal SUSY extension of the Standard Model

    Statistical mechanics of voting

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    Decision procedures aggregating the preferences of multiple agents can produce cycles and hence outcomes which have been described heuristically as `chaotic'. We make this description precise by constructing an explicit dynamical system from the agents' preferences and a voting rule. The dynamics form a one dimensional statistical mechanics model; this suggests the use of the topological entropy to quantify the complexity of the system. We formulate natural political/social questions about the expected complexity of a voting rule and degree of cohesion/diversity among agents in terms of random matrix models---ensembles of statistical mechanics models---and compute quantitative answers in some representative cases.Comment: 9 pages, plain TeX, 2 PostScript figures included with epsf.tex (ignore the under/overfull \vbox error messages

    Exact Scale Invariance in Mixing of Binary Candidates in Voting Model

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    We introduce a voting model and discuss the scale invariance in the mixing of candidates. The Candidates are classified into two categories μ∈{0,1}\mu\in \{0,1\} and are called as `binary' candidates. There are in total N=N0+N1N=N_{0}+N_{1} candidates, and voters vote for them one by one. The probability that a candidate gets a vote is proportional to the number of votes. The initial number of votes (`seed') of a candidate μ\mu is set to be sμs_{\mu}. After infinite counts of voting, the probability function of the share of votes of the candidate μ\mu obeys gamma distributions with the shape exponent sμs_{\mu} in the thermodynamic limit Z0=N1s1+N0s0→∞Z_{0}=N_{1}s_{1}+N_{0}s_{0}\to \infty. Between the cumulative functions {xμ}\{x_{\mu}\} of binary candidates, the power-law relation 1−x1∼(1−x0)α1-x_{1} \sim (1-x_{0})^{\alpha} with the critical exponent α=s1/s0\alpha=s_{1}/s_{0} holds in the region 1−x0,1−x1<<11-x_{0},1-x_{1}<<1. In the double scaling limit (s1,s0)→(0,0)(s_{1},s_{0})\to (0,0) and Z0→∞Z_{0} \to \infty with s1/s0=αs_{1}/s_{0}=\alpha fixed, the relation 1−x1=(1−x0)α1-x_{1}=(1-x_{0})^{\alpha} holds exactly over the entire range 0≤x0,x1≤10\le x_{0},x_{1} \le 1. We study the data on horse races obtained from the Japan Racing Association for the period 1986 to 2006 and confirm scale invariance.Comment: 19 pages, 8 figures, 2 table

    Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

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    Coherent elastic neutrino-nucleus scattering (CEν\nuNS) is a process in which neutrinos scatter on a nucleus which acts as a single particle. Though the total cross section is large by neutrino standards, CEν\nuNS has long proven difficult to detect, since the deposited energy into the nucleus is ∼\sim keV. In 2017, the COHERENT collaboration announced the detection of CEν\nuNS using a stopped-pion source with CsI detectors, followed up the detection of CEν\nuNS using an Ar target. The detection of CEν\nuNS has spawned a flurry of activities in high-energy physics, inspiring new constraints on beyond the Standard Model (BSM) physics, and new experimental methods. The CEν\nuNS process has important implications for not only high-energy physics, but also astrophysics, nuclear physics, and beyond. This whitepaper discusses the scientific importance of CEν\nuNS, highlighting how present experiments such as COHERENT are informing theory, and also how future experiments will provide a wealth of information across the aforementioned fields of physics

    Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

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    Coherent elastic neutrino-nucleus scattering (CEν\nuNS) is a process inwhich neutrinos scatter on a nucleus which acts as a single particle. Thoughthe total cross section is large by neutrino standards, CEν\nuNS has longproven difficult to detect, since the deposited energy into the nucleus is∼\sim keV. In 2017, the COHERENT collaboration announced the detection ofCEν\nuNS using a stopped-pion source with CsI detectors, followed up thedetection of CEν\nuNS using an Ar target. The detection of CEν\nuNS hasspawned a flurry of activities in high-energy physics, inspiring newconstraints on beyond the Standard Model (BSM) physics, and new experimentalmethods. The CEν\nuNS process has important implications for not onlyhigh-energy physics, but also astrophysics, nuclear physics, and beyond. Thiswhitepaper discusses the scientific importance of CEν\nuNS, highlighting howpresent experiments such as COHERENT are informing theory, and also how futureexperiments will provide a wealth of information across the aforementionedfields of physics.<br
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