4,713 research outputs found

    Universality and Critical Behavior at the Critical-End-Point on Itinerant-Metamagnet UCoAl

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    We performed nuclear-magnetic-resonance (NMR) measurements on itinerant-electron metamagnet UCoAl in order to investigate the critical behavior of the magnetism near a metamagnetic (MM) critical endpoint (CEP). We derived c-axis magnetization McM_c and its fluctuation ScS_c from the measurements of Knight shift and nuclear spin-lattice relaxation rate 1/T11/T_1 as a function of the c-axis external field (HcH_c) and temperature (TT). We developed contour plots of McM_c and ScS_c on the HcH_c - TT phase diagram, and observed the strong divergence of ScS_c at the CEP. The critical exponents of McM_c and ScS_c near the CEP are estimated, and found to be close to the universal properties of a three-dimensional (3-D) Ising model. We indicate that the critical phenomena at the itinerant-electron MM CEP in UCoAl have a common feature as a gas-liquid transition.Comment: 8 Pages, 14 figure

    Spectroscopic Observation on the Combustion Characteristics of Japanese Traditional Oil Lamp

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    In this research, spectroscopic measurement has been made to investigate the combustion characteristics of a Japanese traditional oil lamp, called toumyou, that has been used since ancient periods until present. Combustion characteristics, i.e. flame stability and temperature, were analyzed by using a temperature video camera. Spectral emission intensity of hydroxyl (OH) radical (band head of 310 nm) was measured by using a UV-visible spectrometer and visualized by a CCD camera while the brightness was measured using a lux meter. The experimental result showed that the flames of vegetable oils burned were stable and temperatures ranged over about 1000-2500ºC. In addition, the emission intensity of OH radical was successfully detected by the UV-visible spectrometry and visualized by the CCD Camera. The emission intensities of OH radical from flames of coconut oil and palm oil were higher than those of other tested vegetable oils. From measurement using a lux meter, it was obtained that coconut oil gives the brightest flame

    Scalable Spin Amplification with a Gain over a Hundred

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    We propose a scalable and practical implementation of spin amplification which does not require individual addressing nor a specially tailored spin network. We have demonstrated a gain of 140 in a solid-state nuclear spin system of which the spin polarization has been increased to 0.12 using dynamic nuclear polarization with photoexcited triplet electron spins. Spin amplification scalable to a higher gain opens the door to the single spin measurement for a readout of quantum computers as well as practical applications of nuclear magnetic resonance (NMR) spectroscopy to infinitesimal samples which have been concealed by thermal noise.Comment: 6 pages, 7 figure

    Action Sounds Modulate Arm Reaching Movements

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    Our mental representations of our body are continuously updated through multisensory bodily feedback as we move and interact with our environment. Although it is often assumed that these internal models of body-representation are used to successfully act upon the environment, only a few studies have actually looked at how body-representation changes influence goal-directed actions, and none have looked at this in relation to body-representation changes induced by sound. The present work examines this question for the first time. Participants reached for a target object before and after adaptation periods during which the sounds produced by their hand tapping a surface were spatially manipulated to induce a representation of an elongated arm. After adaptation, participants' reaching movements were performed in a way consistent with having a longer arm, in that their reaching velocities were reduced. These kinematic changes suggest auditory-driven recalibration of the somatosensory representation of the arm morphology. These results provide support to the hypothesis that one's represented body size is used as a perceptual ruler to measure objects' distances and to accordingly guide bodily actions
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