191 research outputs found

    Electroencephalogram-based control of an electric wheelchair

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    This paper presents a study on electroencephalogram (EEG)-based control of an electric wheelchair. The objective is to control the direction of an electric wheelchair using only EEG signals. In other words, this is an attempt to use brain signals to control mechanical devices such as wheelchairs. To achieve this goal, we have developed a recursive training algorithm to generate recognition patterns from EEG signals. Our experimental results demonstrate the utility of the proposed recursive training algorithm and the viability of accomplishing direction control of an electric wheelchair by only EEG signals

    Variations of divalent cation concentrations in pore water and the precipitation of Mg-rich authigenic mineral during early diagenesis of Toyoma Formation

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    The variations of Fe, Mn and Mg concentrations in pore water were deduced from the chemistry of calcite. With depth, the Fe/Ca, Mn/Ca, Mg/Ca ratios of pore water decrease. The decrease in the Fe/Ca ratio is due to the precipitation of pyrite, whereas the decrease in the Mn/Ca ratio is due to the precipitation of Mn-rich calcite. The depletion of Mg in pore water is ascribed to the precipitation of either Mg-rich smectite or Mg-rich chlorite. A-type rock is further divided into A1 and A2 subtypes, on the basis of δ13C. Excesses of MgO and deficiencies of K舀 O above the calculated whole-rock compositions are observed mainly in the phosphatic nodules and A1 subtype. This suggests that the formation of Mg-rich smectite or Mg-rich chlorite took place at very early stage of diagenesis of the Toyoma Formation.Article信州大学理学部紀要 38: 23-34(2004)departmental bulletin pape

    Production of overdense plasmas by launching 2,45 GHz electron cyclotron waves in a helical device

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    For production of low temperature plasmas with low collisionality, 2.45GHz microwave power up to 20kW is injected perpendicularly to the toroidal field at very low toroidal field BtComment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

    Lower tropospheric vertical distribution of aerosol particles over Syowa Station, Antarctica from spring to summer 2004

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    Vertical distributions of atmospheric aerosol particles were measured nine times up to 5200 m a.s.l. using an aircraft over Syowa Station, East Antarctica during September-December 2004. Measurements were made for number concentrations of condensation nuclei (CN, Dp>10 nm), number-size distribution larger than 0.3 μm diameter, air temperature, humidity, and GPS position. During spring, the vertical profile of CN concentration showed large variability (100-1000 cm^(-3)), but it was mostly constant in summer. Vertical profiles of number-size distribution larger than 0.3 μm showed a systematic shift at altitudes greater than 4000 m. Both concentrations of aerosol number for Dp>0.3 μm and integrated volume between 0.3 and 1.0 μm showed constantly lower values at altitudes greater than 4000 m. These data suggest that the shift of aerosol parameters results from depletion of coarse particles such as sea salts. Maximum concentrations of the volume and CN were obtained respectively from the profiles on 7 October and 29 November 2004. These events are interpreted as sources and transport processes based on synoptic meteorological data, an ocean color index produced by SeaWiFS, and backward air trajectory analysis

    The genesis of phosphatic and carbonate rocks in the Toyoma Formation, Northeastern Japan

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    Various phosphatic and carbonate rocks occur in the Upper Permian Toyoma Formation. They are classified into phosphatic nodules, A-, B-and C-type rocks.The isotopic ratios of whole-rock calcite,pyrite and apatite in the rocks and the results of pyrite microanalysis using a high-resolution secondary ion mass spectrometer are presented. The carbon and sulfur isotopic compositions indicate that the rocks were formed through microbial sulfate reduction. Three distinct zones have been recognized within the Toyoma Formation that define its early diagenesis. The three zones’compositions differ in their mole fractions of authigenic material and the δ13C of their calcite deposits. Zone 1 is the region of oxic surface sediment in which sulfur-oxidizing bacteria grew.Because sulfuric acid is generated by the chemosynthesis of the bacteria, biogenic phosphate debris such as fish bones and scales were dissolved.The phosphate ions thus formed were the source of the phosphatic rocks of the Toyoma Formation.Zone 2 is the anoxic zone that underlay Zone 1. Anaerobic sulfate-reducing bacteria grew in this zone, resulting in increased pore water alkalinity and the precipitation of pyrite and apatite. Phosphatic nodules and A-and B-type rocks began to grow in this zone.Zone 3 is characterized by calcite precipitation. The pore water, saturated with calcite components, segregated from the sediments into rocks allowing the rocks to be calcareous. As sediments became buried deeper and deeper, they experienced the conditions of each successive zone. However, the period of final consolidation of the rocks differed from one rock type to another as evidenced by the varying δ1C values for calcite contained in the different rock types. Although the rocks are mixtures of authigenic minerals originating in different zones, it was possible to estimate the range of diagenetic zones in which each rock type was formed.ArticleJournal of the Faculty of Science Shinshu University 44: 1-57(2012)departmental bulletin pape

    Experimental Simulation of High Temperature Plasma Transport Using Almost Dimensionally Similar Cold Plasmas in the Compact Helical System

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    In the Compact Helical System (CHS), experimental simulation of high temperature plasma transport is attempted by using cold plasma having similar dimensionless parameters such as electron-ion collision frequency normalized by bounce frequency v*ei, averaged toroidal beta value βt and the normalized gyro radius ρs*. The cold plasma is produced by 2.45 GHz electron cyclotron waves at very low toroidal field less than 0.1 T, and has v*ei ~ 0.05?1, βt < 0.02 % and ρs* ~ 0.02?0.05. The radial profiles of fluctuation amplitude have similarity to those in a high temperature plasma. In the cold plasma with low v*ei < 0.1, internal transport barrier is clearly formed in electron density and temperature profiles when the radial electric field rapidly evolves to positive value

    CORONARY ARTERY MORPHPLOGY AND REACTIVITY TO ACUTE HYPOXIA IN CHRONIC PULMONARY DISEASE

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    In patients with chronic pulmonary disase (CPD), myocardial infarction is rare. To elucidate why this is so, we investigated the morphological changes and the reactivity of the coronary artery to acute hypoxia in patients with CPD. Sixty patients with CPD and 28 normal subjects were studied. Measurements of pulmonary homodynamics and coronary angiography were undertaken before and after inhalation of 13%O2 for 15 minutes. The size of the coronary arteries was measured using a densitometric method, and a coronary narrowing score was calculated according to the WHO criteria. The size of the left anterior descending artery of patients with low %VC and hypoxia was larger than that of the normal subjects. In patients with CPD, the coronary narrowing score was low and the atherosclerotic change was minimal. The reactivity of the coronary arteries to acute hypoxia was reduced in patients with CPD when compared with normal subjects

    市販茶系飲料の示すフリーラジカル消去活性

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    Tea drinks, prepared from the tea plant classified as Camellia sinensis, contain antioxidative phenolic compounds, like catechins and flavonols. We evaluated the free radical scavenging activities of tea drinks on the market by measuring luminol-amplified chemiluminescence stimulated by the free radical initiator 2,2'-azobis (2-amidinopropane9 dihydrochloride, and the absorption of 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) radica cation at 734 nm. Black tea drinks and green tea drinks mostly showed high free radical scavenging activities in either assay, followed in order by oolong tea drinks and blend tea drinks that contain extracts from plants other than the tea plant. Total phenol contents in tea drinks highly correlated with their free radical scavenging activities, indicating polyphenols in tea drinks are the major components contributing to the free radical scavenging activities of tea drinks
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