1,067 research outputs found

    Dehydrogenation Catalyst for Organic Hydride on the Basis of Superheated Liquid-Film Concept

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    Reversible reaction couples of hydrogenation and dehydrogenation of organic compounds e.g. methylcyclohexane and toluene, or 2-propanol and acetone, are described in terms of hydrogen supplier to fuel cells, which will satisfy our demands of combined heat and power at various compact sizes. Carbon supported nano-sized metal particles, wetted with the liquid substrate in a reactor, was used for conversion of organic hydrides into hydrogen and organic compounds, being separable by distillation. Vigorous nucleate boiling is important for heat transfer as well as for irreversible bubble evolution, leading hydrogen to the vapor phase. Once the bubble is broken at the interface, catalytic hydrogenation will be prohibited, because gaseous hydrogen is unable to dissolve into the boiling liquid. Catalytic dehydrogenation under superheated liquid-film conditions can thus convert low-quality heats into hydrogen energy

    Brain correlates of task-load and dementia elucidation with tensor machine learning using oddball BCI paradigm

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    Dementia in the elderly has recently become the most usual cause of cognitive decline. The proliferation of dementia cases in aging societies creates a remarkable economic as well as medical problems in many communities worldwide. A recently published report by The World Health Organization (WHO) estimates that about 47 million people are suffering from dementia-related neurocognitive declines worldwide. The number of dementia cases is predicted by 2050 to triple, which requires the creation of an AI-based technology application to support interventions with early screening for subsequent mental wellbeing checking as well as preservation with digital-pharma (the so-called beyond a pill) therapeutical approaches. We present an attempt and exploratory results of brain signal (EEG) classification to establish digital biomarkers for dementia stage elucidation. We discuss a comparison of various machine learning approaches for automatic event-related potentials (ERPs) classification of a high and low task-load sound stimulus recognition. These ERPs are similar to those in dementia. The proposed winning method using tensor-based machine learning in a deep fully connected neural network setting is a step forward to develop AI-based approaches for a subsequent application for subjective- and mild-cognitive impairment (SCI and MCI) diagnostics.Comment: In ICASSP 2019 - 2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), pp. 8578-8582, May 201

    Multilayer gas cells for sub-Doppler spectroscopy

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    We have carried out theoretical research on ultra-high resolution spectroscopy of atoms (or molecules) in the suggested cell with a series of plane-parallel thin gas layers between spatially separated gas regions of this cell for optical pumping and probing. It is shown the effective velocity selection of optically pumped atoms because of their specific transit time and collisional relaxation in such a cell, which lead to narrow sub-Doppler resonances in absorption of the probe monochromatic light beam. Resolution of this spectroscopic method is analyzed in cases of stationary and definite nonstationary optical pumping of atoms by the broadband radiation versus geometrical parameters of given cells and pumping intensity. The suggested multilayer gas cell is the compact analog of many parallel atomic (molecular) beams and may be used also as the basis of new compact optical frequency standards of high accuracy.Comment: 12 pages, 4 figure

    Simulation and Design of a Simple and Easy-to-use Small-scale Neutron Source at Kyoto University

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    AbstractA simple and easy-to-use compact neutron source based on a low power level proton accelerator (proton energy 3.5 MeV and 0.35kW beam power) at Kyoto University was designed with the conception of low cost, compact size, high safety and intensive thermal neutron flux via Monte Carlo method with PHITS code. By utilizing (p, n) reactions in a beryllium target coupled to a polyethylene moderator and graphite reflector with a wing configuration, this facility is expected to produce time-averaged thermal neutron fluxes suitable for neutron scattering and development of instrumentation, and play a role in educating students in neutron science and performing research with neutrons. Borated polyethylene (BPE) and ordinary concrete were combined to shield the neutron and photon. By using niobium as target backing and water as cooler, it is promising to cope with the problem of thermal damage and hydrogen embrittlement damage. The sizes of moderator and reflector are optimized to have thermal neutron flux as high as possible, while keeping the low ratio of fast neutron flux to thermal neutron flux. The neutron and gamma dose equivalent rates were evaluated and the current shielding configuration is acceptable

    STRUCTURAL RELAXATION IN AMORPHOUS Fe_<40>Ni_<40>P_<14>B_<6> ALLOY STUDIED BY POSITRON ANNIHILATION AND ELECTRICAL RESISTIVITY MEASUREMENT

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    The Doppler broadening lineshape of 511 keV γ-ray emitted from positron annihilation, positron lifetime and electrical resistivity of the Fe_Ni_P_B_ amorphous alloy have been measured for the isochronal annealing of 0-500 ℃ temperature range. W-parameter of the Doppler broadening lineshape increased in two stages by annealing below crystallization temperature. These increases appear to be due to the loss of excess free volume in the amorphous alloy. The results indicate that structure of this amorphous alloy relax in two stages and excess free volume losses in the two stage

    Geochemical study of ultramafic rocks from Latowu area of North Kolaka, Southeast Sulawesi and its implication for CO2 sequestration

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    Geochemistry of ultramafic rocks in the Latowu Area of North Kolaka Regency, Southeast Sulawesi has been investigated with the aim at deciphering of mineral characteristics, chemical composition and their potential use as carbon dioxide storage. Mineralogy was characterized by both scanning electron microscopy (SEM) and X-ray diffractometry (XRD); whereas bulk rock and mineral chemistry were analyzed by means of X-ray fluorescence spectrometry (XRF) and Electron probe microanalyzer (EPMA) respectively. Results of analyses show that lizardite is predominant serpentine mineral present, followed by chrysotile and trace amount of magnetite. Remnants of olivine and pyroxene were detected in some samples but they have been pseudomorphicly replaced by serpentine. Serpentinization of Latowu ultramafic rocks has led to decrease in grain size and density. Lizardite is characterized by fine grained particles with higher in iron. The higher Mg and Fe of the rocks indicate a suitability as feed materials for carbon dioxide sequestration. Mineral and chemical properties of ultramafic rocks have significant role in evaluating the feasibility of mineral carbonation
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