Time-domain sensitivity enhancement in pulsed Pb-TDL gas monitors

A Pb-salt tunable diode laser (TDL) has found many applications in the field of atmospheric gas analysis. Its continuous tunablility and fine spectral purity in the mid infrared region are outstanding from other lasers. The only shortcoming is that it requires cryogenic operating temperatures, though, it is improved year by year towards the room temperature operation. A repeated pulse operation of Pb salt diode lasers is possible with a thermoelectric cooling device, which allows an instrument a portable geometry disusing a heavy, bulky and power consuming mechanical refrigerator. A derivative spectrometry was exploiting the quick tunability of Pb salt diode lasers, though they are continuous wave (cw) operated with refrigerator or liquid nitrogen so far. A new system for derivative spectrometry with a pulsed diode laser will extend its field of applications because of reduced weights and size of measuring instruments. A preliminary results is shown that demonstrates the feasibility of an attempt to implement the derivative spectrmetry with repeatedly pulse driven diode lasers. Atmospheric methane was measured with 8 ppm/m sensitivity. Further results of parametric optimization for the best signal to noise ratios under any given device characteristics as well as for available real devices is given

Random matrix model at nonzero chemical potentials with anomaly effects

Phase diagram of the chiral random matrix model with U(1)A breaking term is studied with the quark chemical potentials varied independently at zero temperature, by taking the chiral and meson condensates as the order parameters. Although, without the U(1)A breaking term, chiral transition of each flavor can happen separately responding to its chemical potential, the U(1)A breaking terms mix the chiral condensates and correlate the phase transitions. In the three flavor case, we find that there are mixings between the meson and chiral condensates due to the U(1)A anomaly, which makes the meson condensed phase more stable. Increasing the hypercharge chemical potential ($\mu_Y$) with the isospin and quark chemical potentials ($\mu_I$, $\mu_q$) kept small, we observe that the kaon condensed phase becomes the ground state and at the larger $\mu_Y$ the pion condense phase appears unexpectedly, which is caused by the competition between the chiral restoration and the meson condensation. The similar happens when $\mu_Y$ and $\mu_I$ are exchanged, and the kaon condensed phase becomes the ground state at larger $\mu_I$ below the full chiral restoration.Comment: 12 pages, 8 figure

Long-range nematic order and anomalous fluctuations in suspensions of swimming filamentous bacteria

We study the collective dynamics of elongated swimmers in a very thin fluid layer by devising long, filamentous, non-tumbling bacteria. The strong confinement induces weak nematic alignment upon collision, which, for large enough density of cells, gives rise to global nematic order. This homogeneous but fluctuating phase, observed on the largest experimentally-accessible scale of millimeters, exhibits the properties predicted by standard models for flocking such as the Vicsek-style model of polar particles with nematic alignment: true long-range nematic order and non-trivial giant number fluctuations.Comment: 6 pages, 4 figures. Supplemental Material: 6 pages, 3 figure

Analysis of the U.S.-Mexico Sugar Trade - 10 Years of NAFTA Regime and 10 Years from Now

The U.S.- Mexico sugar trade was examined, paying a close attention to the provisions of North American Free Trade Agreement (NAFTA) and the circumstances surrounding the industries of the two countries. Quantitative analyses provided the outlook of the future sugar market and shed light on the political implications.International Relations/Trade,

Recombining Plasma & Gamma-ray Emission in the Mixed-morphology Supernova Remnant 3C 400.2

3C 400.2 belongs to the mixed morphology supernova remnant class, showing center-filled X-ray and shell-like radio morphology. We present a study of 3C 400.2 with archival Suzaku and Fermi-LAT observations. We find recombining plasma (RP) in the Suzaku spectra of north-east and south-east regions. The spectra of these regions are well described by two-component thermal plasma models: The hard component is in RP, while the soft component is in collisional ionization equilibrium (CIE) conditions. The RP has enhanced abundances indicating that the X-ray emission has an ejecta origin, while the CIE has solar abundances associated with the interstellar material. The X-ray spectra of north-west and south-west regions are best fitted by a two-component thermal plasma model: an ionizing and a CIE plasma. We have detected GeV gamma-ray emission from 3C 400.2 at the level of $\sim$5$\sigma$ assuming a point-like source model with a power-law (PL) type spectrum. We have also detected a new GeV source at the level of $\sim$13$\sigma$ assuming a Gaussian extension model with a PL type spectrum in the neighborhood of the SNR. We report the analysis results of 3C 400.2 and the new extended gamma-ray source and discuss the nature of gamma-ray emission of 3C 400.2 in the context of existing NANTEN CO data, DRAO HI data, and the Suzaku X-ray analysis results.Comment: Accepted to be published in the Astrophysical Journa