7,234 research outputs found

    Superfluid-insulator transition of the Josephson junction array model with commensurate frustration

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    We have studied the rationally frustrated Josephson-junction array model in the square lattice through Monte Carlo simulations of (2+1)(2+1)D XY-model. For frustration f=1/4f=1/4, the model at zero temperature shows a continuous superfluid-insulator transition. From the measurement of the correlation function and the superfluid stiffness, we obtain the dynamical critical exponent z=1.0z=1.0 and the correlation length critical exponent Μ=0.4±0.05\nu=0.4 \pm 0.05. While the dynamical critical exponent is the same as that for cases f=0f=0, 1/2, and 1/3, the correlation length critical exponent is surprisingly quite different. When f=1/5f=1/5, we have the nature of a first-order transition.Comment: RevTex 4, to appear in PR

    N_pN_n dependence of empirical formula for the lowest excitation energy of the 2^+ states in even-even nuclei

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    We examine the effects of the additional term of the type ∌e−λâ€ČNpNn\sim e^{- \lambda' N_pN_n} on the recently proposed empirical formula for the lowest excitation energy of the 2+2^+ states in even-even nuclei. This study is motivated by the fact that this term carries the favorable dependence of the valence nucleon numbers dictated by the NpNnN_pN_n scheme. We show explicitly that there is not any improvement in reproducing Ex(21+)E_x(2_1^+) by including the extra NpNnN_pN_n term. However, our study also reveals that the excitation energies Ex(21+)E_x(2_1^+), when calculated by the NpNnN_pN_n term alone (with the mass number AA dependent term), are quite comparable to those calculated by the original empirical formula.Comment: 14 pages, 5 figure

    Synergistic Trap Response of the False Stable Fly and Little House Fly (Diptera: Muscidae) to Acetic Acid and Ethanol, Two Principal Sugar Fermentation Volatiles

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    In an initial observation, large numbers of muscoid flies (Diptera) were captured as nontarget insects in traps baited with solutions of acetic acid plus ethanol. In subsequent field experiments, numbers of false stable fly Muscina stabulans (Fallén) and little house fly Fannia canicularis (L.) trapped with the combination of acetic acid plus ethanol were significantly higher than those trapped with either chemical alone, or in unbaited traps. Flies were trapped with acetic acid and ethanol that had been formulated in the water of the drowning solution of the trap, or dispensed from polypropylene vials with holes in the vial lids for diffusion of evaporated chemical. Numbers of both species of fly captured were greater with acetic acid and ethanol in glass McPhail traps, compared to four other similar wet trap designs. This combination of chemicals may be useful as an inexpensive and not unpleasant lure for monitoring or removing these two pest fly specie

    Development of Bis-GMA-free biopolymer to avoid estrogenicity

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    Objective: Although bisphenol A-glycidyl methacrylate (Bis-GMA)-based dental materials are widely used in dentistry, Estrogenicity from released bisphenol A remains a concern due to possibility of adversely affecting the growth of children and homeostasis of adults. Here, a new family of isosorbide-derived biomonomers were synthesized and experimentally utilized as a matrix of dental sealants to provide physico-mechanical and biological properties comparable to those of a conventional Bis-GMA-based material but without the the potential estrogenicity. / Methods: After synthesis of isosorbide-derived biomonomers (ISDB) by light polymerization, an experimental dental sealant with different silica filler concentrations (0–15 wt%) was characterized and compared to a commercially available Bis-GMA-based sealant. Cytotoxicity and estrogenicity assays were conducted with human oral keratinocytes and estrogen-sensitive MCF-7 cells, respectively. / Results: ISDB-based dental sealants exhibited typical initially smooth surfaces with depth of cure, Vickers hardness, compressive strength/modulus, water resorption/solubility, and flowability comparable to those of the commercial sealant and met the ISO standard for dental sealants and polymer-based restorative materials. Indirect cytotoxicity tests using an extract showed comparable viability among experimental ISDB-based materials and a commercial Bis-GMA-incorporated control. DNA synthesis in MCF-7 cells (a marker of estrogenicity) and the release of bisphenol A under enzymatic incubation were not detected in ISDB-based materials. / Significance: In conclusion, the comparable physico-mechanical properties of ISDB-based materials with their cytocompatibility and lack of estrogenicity suggest the potential usefulness of ISDBs as a newly developed and safe biomaterial

    Fine structure of alpha decay in odd nuclei

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    Using an alpha decay level scheme, an explanation for the fine structure in odd nuclei is evidenced by taking into account the radial and rotational couplings between the unpaired nucleon and the core of the decaying system. It is stated that the experimental behavior of the alpha decay fine structure phenomenon is directed by the dynamical characteristics of the system.Comment: 8 pages, 3 figures, REVTex, submitted to Physical Review

    Magnetic field measurements and radiation simulation for a superconducting transverse-gradient undulator

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    The transverse gradient undulator (TGU) concept is a way to enable short-gain length free electron lasers with laser-plasma accelerated electron bunches, although their energy spread is typically in the percent range. In this contribution, we report on the magnetic field measurements on a 40-period superconducting TGU designed, manufactured and commissioned at the Karlsruhe Institute of Technology (KIT). As the figure of merit for the field quality, tracking and radiation field simulations, based on the measured fields, will be presented

    An implicit method for radiative transfer with the diffusion approximation in SPH

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    An implicit method for radiative transfer in SPH is described. The diffusion approximation is used, and the hydrodynamic calculations are performed by a fully three--dimensional SPH code. Instead of the energy equation of state for an ideal gas, various energy states and the dissociation of hydrogen molecules are considered in the energy calculation for a more realistic temperature and pressure determination. In order to test the implicit code, we have performed non--isothermal collapse simulations of a centrally condensed cloud, and have compared our results with those of finite difference calculations performed by MB93. The results produced by the two completely different numerical methods agree well with each other.Comment: 25 pages, 9 figure
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