2,423 research outputs found

    On Electrical Equivalence of Aperture-Body and Transmission-Cavity Resonance Phenomena in Subwavelength Conducting Aperture Systems from an Equivalent Circuit Point of View

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    For a narrow slit structure backed by a conducting strip which is taken as a representative example of an aperture-body resonance (ABR) problem, the transmission resonance condition (i.e., condition for maximum power transmission) and the transmission width (i.e., normalized maximum transmitted power through the slit) are found to be the same as those for narrow slit coupling problem in a thick conducting screen, which is designated as a transmission-cavity resonance (TCR) problem. From a viewpoint of equivalent circuit representation for the transmission resonance condition and the funneling mechanism, the ABR and the TCR problems are thought to be essentially of the same nature.Comment: 14 pages, 3 figure

    The effect of phenylephrine on the onset time of rocuronium

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    BACKGROUND: Several studies have demonstrated that ephedrine shortens the onset time of muscle relaxants, and it does so probably by increasing the cardiac output. However, elevation of the systemic blood pressure through α adrenergic stimulation via ephedrine may affect the onset of muscle relaxants during the induction of anesthesia. We investigated the effect of phenylephrine, which is a selective α-1 agonist, on the onset time of rocuronium and the intubating conditions in adults after the administration of propofol. METHODS: Sixty-four patients were randomly assigned to two groups. Phenylephrine (0.9 µg/kg) (P group) or the same volume of saline (S group) was injected before rocuronium (0.6 mg/kg) administration. Anesthesia was induced with fentanyl 2 µg/kg and propofol 2 mg/kg. The onset time was defined as the time from the end of rocuronium injection to the time when a single twitch height gets to 0% or the minimum level. A well-trained anesthesiologist who was 'blinded' to the treatment groups evaluated the intubating conditions. The mean arterial pressure and heart rate were recorded before induction, before intubation, immediately after intubation and 1 minute and 2 minutes after intubation. RESULTS: The onset time was 84 ± 18 sec in the P-group and 72 ± 14 sec in the S-group. There was no difference of the intubating conditions, the mean arterial pressure and the heart rate between the two groups. CONCLUSIONS: A small dose of phenylephrine, which has a limited effect on blood pressure, delayed the onset time of rocuronium after the administration of propofol, and the vasoconstriction effect of phenylephrine may affect the prolongation of the rocuronium onset time at the induction of anesthesia with using propofol.ope

    Cored Dark Matter halos in the Cosmic Neutrino Background

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    We study the impact of the interaction between DM and the cosmic neutrino background on the evolution of galactic dark matter halos. The energy transfer from the neutrinos to the dark matter can heat the center of the galaxy and make it cored. This effect is efficient for the small galaxies such as the satellite galaxies of the Milky Way and we can put conservative constraint on the non-relativistic elastic scattering cross section as σχν1031cm2\sigma_{\chi\nu}\lesssim 10^{-31} {\rm cm}^2 for 0.1 keV dark matter and 0.1 eV neutrino.Comment: 7 pages, 5 figure

    Online home appliance control using EEG-Based brain-computer interfaces

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    Brain???computer interfaces (BCIs) allow patients with paralysis to control external devices by mental commands. Recent advances in home automation and the Internet of things may extend the horizon of BCI applications into daily living environments at home. In this study, we developed an online BCI based on scalp electroencephalography (EEG) to control home appliances. The BCI users controlled TV channels, a digital door-lock system, and an electric light system in an unshielded environment. The BCI was designed to harness P300 andN200 components of event-related potentials (ERPs). On average, the BCI users could control TV channels with an accuracy of 83.0% ?? 17.9%, the digital door-lock with 78.7% ?? 16.2% accuracy, and the light with 80.0% ?? 15.6% accuracy, respectively. Our study demonstrates a feasibility to control multiple home appliances using EEG-based BCIs

    The North Pacific Oxygen Uptake Rates Over the Past Half-Century

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    The transport of dissolved oxygen (O2) from the surface ocean into the interior is a critical process sustaining aerobic life in mesopelagic ecosystems, but its rates and sensitivity to climate variations are poorly understood. Using a circulation model constrained to historical variability by assimilation of observations, we show that the North Pacific thermocline effectively takes up O2 primarily by expanding the area through which O2-rich mixed layer water is detrained into the thermocline. The outcrop area during the critical winter season varies in concert with the Pacific Decadal Oscillation (PDO). When the central North Pacific Ocean is in a cold phase, the winter outcrop window for the Central Mode Water class (CMW; a neutral density range of γ = 25.6 - 26.6) expands southward allowing more O2-rich surface water to enter the ocean’s interior. An increase in volume flux of water to the CMW density class is partly compensated by a reduced supply to the shallower densities of Subtropical Mode Water (γ = 24.0 - 25.5). The thermocline has become better oxygenated since the 1980s due partly to strong O2 uptake. Positive O2 anomalies appear first near the outcrop and subsequently downstream in the subtropical gyre. In contrast to the O2 variations within the ventilated thermocline, observed O2 in Intermediate Water (density range of γ = 26.7 – 27.2) shows a declining trend over the past half-century, a trend not explained by the open ocean water mass formation rate
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