494 research outputs found

    Difference in the Physics Education in Lower Secondary Level between Japan and Germany - A Comparative Study between the Recent Textbooks -

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     ドイツ・ザクセン邦のギムナジウム中級段階の教科物理と日本の中学校の教科理科における物理分野に焦点を当て, 教科書などを手がかりにし, 比較を行い,期間・広がり・詳しさにおいて,違いを見いだした。ドイツでは第6学年から5年間にわたり通年で,日本では第7学年から3年間各学年限られた期間だけ学習されている。週授業時間数の合計はドイツの方が多い。ドイツでは,電磁気学・波動・力学・熱力学・天文学・原子物理学の分野があるが,日本では,電磁気学・力学・波動しかない。ドイツでは,内容に繰り返しと連続性があり,日本ではほとんどない。索引の密度を比較すると,ドイツは日本より大きい。実験に関しては,日本では代表的な実験を授業の中で実施するよう位置付けられているのに対し,ドイツでは多様な実験から自主的に選び実施することができるようになっていることで違っている

    Seismic 1/f Fluctuations from Amplitude Modulated Earth's Free Oscillation

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    We first report that the seismic data from around the world yield 1/f fluctuations if we exclude giant earthquakes. We investigate the origin of this 1/f fluctuation based on our recent proposal: 1/f noise is amplitude modulation and demodulation. We speculate that this amplitude modulation is encoded by the resonance with the Earth Free Oscillation (EFO) and demodulated by fault rupture. We partially demonstrate this scenario by analyzing the EFO eigenmodes. We briefly describe possible verifications of our theory of 1/f fluctuations based on EFO.Comment: 6 pages, 6 figure

    The potential hazard of a non-slip element balloon causing distal longitudinal stent deformation: the first clinical experience and in vitro assessment

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    Background: A new complication, longitudinal stent deformation (LSD), is increasingly reported withrecent intracoronary stent designs. There have been experiences of unusual cases of distal LSD causedby entrapment of a Lacrosse® non-slip element (NSE) balloon (Goodman Co., Ltd., Nagoya, Japan),which has three flexible nylon elements to prevent slippage. Accordingly, the aim of this study is to reportthe clinical experience of distal LSD caused by the NSE in the documented center and to investigate theincidence and mechanisms involved.Methods: Coronary intervention cases were retrospectively reviewed using the NSE balloon in hospitalbetween May 2014 and June 2017. In bench testing, distal LSD was reproduced in a silicon tube modelto identify its mechanism.Results: A total of 95 patients with 107 lesions underwent coronary interventions with NSE. Of these,72 lesions (12 de-novo lesions and 60 in-stent restenosis) were treated using in-stent dilatation. Twodistal LSD cases occurred, representing an incidence of 2.78% (2/72) among all procedures; 16.7%(2/12) of the de-novo lesions developed LSD. In vitro experimentation allowed indentification of themechanisms involved and bailout strategies.Conclusions: This is the first study to evaluate NSE balloon catheter entrapment complicated by distalLSD in which reconstruction of the deformed stent and retrieval of the NSE could be achieved successfully.There is a potential hazard for distal LSD during post-dilatation using the NSE balloon due to itsstructural characteristics. Careful assessment is needed to prevent this complication

    Tunable lasing in doped liquid crystals with one dimensional periodic structure

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    Optical Science and Technology, SPIE's 48th Annual Meeting, 2003, San Diego, California, United StatesMasanori Ozaki, Masahiro Kasano, Kazuhiro Funamoto, Ryotaro Ozaki, Tatsunosuke Matsui, and Katsumi Yoshino "Tunable lasing in doped liquid crystals with one-dimensional periodic structure", Proc. SPIE 5213, Liquid Crystals VII, (5 January 2004). DOI: https://doi.org/10.1117/12.50918

    Termination of Graphene Edges Created by Hydrogen and Deuterium Plasmas

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    Edge engineering is important for both fundamental research and applications as the device size decreases to nanometer scale. This is especially the case for graphene because a graphene edge shows totally different electronic properties depending on the atomic structure and the termination. It has recently been shown that an atomically precise zigzag edge can be obtained by etching graphene and graphite using hydrogen (H) plasma. However, edge termination had not been studied directly. In this study, termination of edges created by H-plasma is studied by high-resolution electron energy loss spectroscopy (HREELS) to show that the edge is sp2\mathrm{sp}^{2} bonded and the edge carbon atom is terminated by only one H atom. This suggests that an ideal zigzag edge, which is not only atomically precise but also sp2\mathrm{sp}^{2} bonding, can be obtained by H-plasma etching. Etching of the graphite surface with plasma of a different isotope, deuterium (D), is also studied by scanning tunneling microscopy (STM) to show that D-plasma anisotropically etches graphite less efficiently, although it can make defects more efficiently, than H-plasma.Comment: 8 pages, 5 figure

    Extreme typhoon wind speeds considering the random variation in a full-scale observation

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    ABSTRACT: In order to estimate the maximum wind speed under typhoon condition, random variation which exists in a full-scale observation recon;l was evaluated. Taking accol,lnt of the random variation, a probabilistic approach was proposed which can compute an extreme distribution of wind speed with the Monte-Carlo method. It was found that the conventional method, which could not evaluate random variation, was apt to underestim~te the maximum wind speed under typhoon condition. The results of the Monte-Carlo simulation by the proposed approach agreed with the distribution that was obtained from observation records

    Stimulated emission from multilayer graphene

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    Monolayer graphene absorbs \sim 2.3 percent of the incident visible light. This "small" absorption was used to emphasize visual transparency of graphene, but in fact it means that multilayer graphene absorbs sizable fraction of incident light, which causes non-negligible fluorescence. In this paper, we study the light emission properties of multilayer graphene composed of tens to hundreds of layers, because these are informative materials having interesting optical properties correlated closely with fluorescence. For example, it was recently predicted that 87-layer graphene absorbs infrared light at maximum efficiency and 20-layer graphene on silicon substrates exhibits zero reflectance (a total absence of backscattering) at a specific visible light wavelength. By modeling light emissions from multilayer graphene using a transfer matrix method, we could quantitatively explain the measured reflectivity from multilayer graphene on silicon substrates. We found sizable corrections, that cannot be classified as incoherent light emissions, to the reflectance of visible light. The new component originates from stimulated emission caused by absorption at each graphene layer, and it is a coherent sum over the amplitudes coming from all graphene layers with a common phase shift of π\pi relative to the incident light. The coherent corrections to the reflectance become dominant for samples thicker than 40-layers and thinner than 160-layers. Multilayer graphene thus functions as a partial coherent light source of various wavelengths and it may have surface-emitting laser applications.Comment: 9 pages, 9 figure

    Evaluation of wind pressure on the low-rise buildings and surrounding terrainunder the influence of tornadolike vortex induced aerodynamic loads

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    Wind loading on buildings caused by straight line boundary layer winds has been thoroughly investigated in the past.The effects of vortex loading on structural projections will induce crosswind loads and torsional loads on low rise buildingwhich has severe dynamic resonant effect not only on the structural projections but also on over all structural elements of abuilding. These structural projections can be in the form of cantilever balconies, canopies, sunshades, overhangs,aesthetically projected elements. The purpose of each of these projections is different and designed to suit the convenienceof habitats. During the tornado, the damage of projections becomes flying debris due to the fatigue effect of fluctuatingpressure. In the present study,a model of low-rise buildings is tested under the influence of tornado-induced vortexes.Models were tested for F3 – F4 tornado for the wind speed 60m/s to 90m/s. Tornadoes of vortex core diameter 0.46 m to1.06 m in a smooth open terrain, simulations were carried out.A prototype of model of building in a scale of 1:400, actualdimensions of building is 20m x 20m x 10 m; the prototype model is prepared using flexi glass. An arrangement is made tostudy the effect of building on the ground terrain in surrounding region of building. Model was provided with pressuretapping to measure the surface pressure on all the walls and roof
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