2,048 research outputs found

    Family number, Wilson line phases and hidden supersymmetry

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    We study the relationship between the family number of chiral fermions and the Wilson line phases, based on the orbifold family unification. We find that flavor numbers are independent of the Wilson line phases relating extra-dimensional components of gauge bosons, as far as the standard model gauge symmetry is respected. This feature originates from a hidden quantum-mechanical supersymmetry.Comment: 17 pages, 1 figur

    Dehydration of main-chain amides in the final folding step of single-chain monellin revealed by time-resolved infrared spectroscopy

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    Kinetic IR spectroscopy was used to reveal β-sheet formation and water expulsion in the folding of single-chain monellin (SMN) composed of a five-stranded β-sheet and an α-helix. The time-resolved IR spectra between 100 μs and 10 s were analyzed based on two consecutive intermediates, I1 and I2, appearing within 100 μs and with a time constant of ≈100 ms, respectively. The initial unfolded state showed broad amide I′ corresponded to a fluctuating conformation. In contrast, I1 possessed a feature at 1,636 cm−1 for solvated helix and weak features assignable to turns, demonstrating the rapid formation of helix and turns. I2 possessed a line for solvated helix at 1,637 cm−1 and major and minor lines for β-sheet at 1,625 and 1,680 cm−1, respectively. The splitting of the major and minor lines is smaller than that of the native state, implying an incomplete formation of the β-sheet. Furthermore, both major and minor lines demonstrated a low-frequency shift compared to those of the native state, which was interpreted to be caused by hydration of the C=O group in the β-sheet. Together with the identification of solvated helix, the core domain of I2 was interpreted as being hydrated. Finally, slow conversion of the water-penetrated core of I2 to the dehydrated core of the native state was observed. We propose that both the expulsion of water, hydrogen-bonded to main-chain amides, and the completion of the secondary structure formation contribute to the energetic barrier of the rate-limiting step in SMN folding

    Relations between the ionization or recombination flux and the emission radiation for hydrogen and helium in plasma

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    On the basis of the collisional-radiative models for neutral hydrogen, and neutral and ionized helium, the relationship between the ionization flux or the recombination flux and the photon emission rate of a representative visible line of each species is investigated. It is found that both fluxes are proportional to the photon emission rate and that the proportionality factor depends rather weakly on the plasma parameters in the ranges of practical interest. This implies that the observed emission line intensity can be a good measure of the ionization flux or the recombination flux. The relation between the total radiation power rate and the ionization or recombination flux is also considered. For a hydrogen plasma in ionization balance the Balmer-alpha line intensity takes the maximum value near the optimum temperature of 1.3 eV, while for plasmas out of ionization balance it takes the minimum near that temperature. This latter characteristic corresponds to the recently observed "inverse edge-localized mode" in divertor plasmas. For neutral hydrogen and ionized helium, it is found that in the recombining plasma of low electron temperature, T_e, and density, n_e, the radiation energy close to the ionization potential of the ground state is emitted during one recombination event. In the ionizing plasma of high Te and low n_e, a similar amount of energy is emitted during one ionization event. Emission line intensities of hydrogen and helium were measured in the Large Helical Device, and the time variation of n_e at the initial and final phases of a discharge was estimated. The results agreed well with the interferometer measurement, and this indicated that the variation of n_e was dominated by their ionization or recombination processes rather than by diffusion. The total radiation energy of hydrogen and helium in the recombining phase was found to be less than 1% of the stored energy of the plasma

    Determination of Manganese in Ferromanganese and Chromium in Ferrochromium by X-Ray Fluorescent Spectroscopy

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    In order to determine alloying elements in ferromanganese and ferrochromium, the application of calibration curve method and of calculation method by Hirokawa\u27s equation was examined. Samples for X-ray irradiation were powder samples and solution samples. Powder samples were prepared by mixing the acid solution of samples with the graphite powder, which was evaporated to dryness. However, the solution samples were prepared by dissolving ferromanganese with nitric acid and by fusing ferrochromium with sodium peroxide. Using these samples, manganese in ferromanganese or chromium in ferrochromium was determined within the standard deviation of about 3.5 per cent
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