THE LOW TEMPERATURE DEPENDENCE OF MAGNETIZATION AND AC SUSCEPTIBILITY OF GLASSY Fe91-xZr7B₂Nix (x =0, 5, 10, 15) ALLOYS

V. Ström,K.S. Kim,B.J. Jönsson,S.C. Yu,A. Inoue,K.V. Rao 한국자기학회 1995 韓國磁氣學會誌 Vol.5 No.5

We have studied the magnetization in fields up to IT at 5K, the saturation magnetization dependence on temperature and the temperature dependence of AC-susceptibility at very low fields (5mOe to 50mOe) of glassy Fe_(91-x)Zr_7B₂Ni_x (x = 0, 5, 10, 15) alloys. The temperature dependence of the magnetization follows the predictions of spin wave excitations with long wavelengths. At zero Ni concentration there is a clear competition between ferromagnetic and antiferromagnetic interactions giving rise to spin-glass behaviour. The addition of Ni drastically modifies the magnetic properties: the antiferromagnetic exchange coupling is reduced and finally disappears, the spin wave stiffness increases from 39.5 to 87.3 meVŲ and Tc increases from 230 K to 478 K. We develop a simple model to quantify the competing interactions and to relate the antiferromagnelically coupled Fe moments to the Ni concentration. We find that the initial susceptibility increases with increasing Ni content along with a decrease of the temperature dependence.

저에너지 양전자 소멸 분광법을 이용한 MgB₂ 박막 구조 특성

이종용(C. Y. Lee),강원남(W. N. Kang),M. Hasegawa,Y. Nagai,K. Inoue 한국진공학회(ASCT) 2008 Applied Science and Convergence Technology Vol.17 No.2

저속 에너지 도플러 넓어짐 양전자 소멸 분광법으로 MgB₂ 박막내의 원자 크기 정도 고체 구조 특성에 대하여 조사하였다. 양전자와 전자의 쌍소멸로 발생하는 511keV 감마선 스펙트럼의 수리적 해석 방법인 S-변수를 사용하여, 상전이 근처 온도에서 박막의 구조 변화를 측정하였다. 비등방성 구조로 된 MgB₂ 박막에서 초전도 특성을 갖는 상전이 온도 근처에서 S-변수를 측정하였다. 양전자의 입사 에너지 10keV에서 측정된 S-변수의 최고치는 박막의 온도가 30K에서 0.567이고, 50 K에서는 0.570로 큰 변화는 없었다. 이 결과로부터 양전자가 Boron 층의 초 전자와 소멸하기 보다는 Mg층 근처의 상 전자와 소멸하는 것으로 판단된다. MgB₂의 박막의 외층은 Mg층으로 이루어졌다고 할 수 있다. Enhance signal-to-noise ratio, slow positron coincidence Doppler Broadening method has been applied to study of characteristics of MgB₂ superconductor film, which were performed at 30 K and 50 K sample temperature near Tc of it. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S, defined as the ratio between the amount of counts in a central portion of the spectrum and the total counts of whole spectrum. The S-parameter values were increased then decreased while the positron implantation energies were increasing, that indicated the diffusion into the samples. The S-parameters of the anisotropic 1 ㎛ MgB₂ thin film which were implanted by positrons at 10 keV are 0.567 at 30 K and 0.570 at 50 K. It is believed that the positrons annihilate with normal-electrons instead of super-electrons in the MgB₂ superconductor.

저에너지 양전자 소멸 분광법을 이용한 MgB₂ 박막 구조 특성

Lee, C.Y.,Kang, W.N.,Nagai, Y.,Inoue, K.,Hasegawa, M. 한국진공학회 2008 Applied Science and Convergence Technology Vol.17 No.2

저속 에너지 도플러 넓어짐 양전자 소멸 분광법으로 $MgB_2$ 박막내의 원자 크기 정도 고체 구조 특성에 대하여 조사하였다. 양전자와 전자의 쌍소멸로 발생하는 511keV 감마선 스펙트럼의 수리적 해석 방법인 S-변수를 사용하여, 상전이 근처 온도에서 박막의 구조 변화를 측정하였다. 비등방성 구조로 된 $MgB_2$ 박막에서 초전도 특성을 갖는 상전이 온도 근처에서 S-변수를 측정하였다. 양전자의 입사 에너지 10keV에서 측정된 S-변수의 최고치는 박막의 온도가 30K에서 0.567이고, 50 K에서는 0.570로 큰 변화는 없었다. 이 결과로부터 양전자가 Boron 층의 초 전자와 소멸하기 보다는 Mg층 근처의 상 전자와 소멸하는 것으로 판단된다. $MgB_2$의 박막의 외층은 Mg층으로 이루어졌다고 할 수 있다. The Characterization of $MgB_2$ Thin Film by Slow Positron Annihilation Spectroscopy Enhance signal-to-noise ratio, slow positron coincidence Doppler Broadening method has been applied to study of characteristics of $MgB_2$ superconductor film, which were performed at 30 K and 50 K sample temperature near Tc of it. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S, defined as the ratio between the amount of counts in a central portion of the spectrum and the total counts of whole spectrum. The S-parameter values were increased then decreased while the positron implantation energies were increasing, that indicated the diffusion into the samples. The S-parameters of the anisotropic 1 ${\mu}m$ $MgB_2$ thin film which were implanted by positrons at 10 keV are 0.567 at 30 K and 0.570 at 50 K. It is believed that the positrons annihilate with normal-electrons instead of super-electrons in the $MgB_2$ superconductor.

Hydrogen-rich gas production from waste plastics by pyrolysis and low-temperature steam reforming over a ruthenium catalyst

Namioka, T.,Saito, A.,Inoue, Y.,Park, Y.,Min, T.j.,Roh, S.a.,Yoshikawa, K. Applied Science Publishers 2011 APPLIED ENERGY Vol.88 No.6

Operating conditions for low-temperature pyrolysis and steam reforming of plastics over a ruthenium catalyst were investigated. In the range studied, the highest gas and lowest coke fractions for polystyrene (PS) with a 60gh<SUP>-1</SUP> scale, continuous-feed, two-stage gasifier were obtained with a pyrolyzer temperature of 673K, steam reforming temperature of 903K, and weight hourly space velocity (WHSV) of 0.10g-sample g-catalyst<SUP>-1</SUP>h<SUP>-1</SUP>. These operating conditions are consistent with optimum conditions reported previously for polypropylene. Our results indicate that at around 903K, the activity of the ruthenium catalyst was high enough to minimize the difference between the rates of the steam reforming reactions of the pyrolysates from polystyrene and polypropylene. The proposed system thus has the flexibility to compensate for differences in chemical structures of municipal waste plastics. In addition, the steam reforming temperature was about 200K lower than the temperature used in a conventional Ni-catalyzed process for the production of hydrogen. Low-temperature steam reforming allows for lower thermal input to the steam reformer, which results in an increase in thermal efficiency in the proposed process employing a Ru catalyst. Because low-temperature steam reforming can be also expected to reduce thermal degradation rates of the catalyst, the pyrolysis-steam reforming process with a Ru catalyst has the potential for use in small-scale production of hydrogen-rich gas from waste plastics that can be used for power generation.

Effect of proportional control treatment on transformation behavior of Ti-50.9at.% Ni shape memory alloys

Park, S.H.,Lee, J.H.,Nam, T.H.,Lee, Y.J.,Inoue, K.,Lee, S.W.,Kim, J.I. Elsevier Sequoia 2013 Journal of alloys and compounds Vol.577 No.suppl1

In this study, the shape memory behavior of Ti-50.9at.% Ni alloys with time gradient annealing (TGA) was investigated via differential scanning calorimetry (DSC) and thermal cycling tests under constant load. The ingot was prepared using a high-frequency induction vacuum furnace. The as-cast ingot was hot forged and extruded, followed by cold-drawing and intermediate annealing to produce wires of 1.0mm in diameter, with a final cold-drawing of 30% reduction in cross-section. For the TGA treatment, a new type of radiant furnace was designed to maintain a constant temperature and create a time gradient along the length of the specimen. According to DSC measurements, a 34K variation in the R-phase transformation interval (i.e., R<SUB>s</SUB>-R<SUB>f</SUB>) was obtained along the length of the specimen (80mm) that was time-gradient annealed from 3min to 20min at 773K. The results of thermal cycling tests under constant load revealed that the temperature dependence of transformation elongation (d@?/dT) of the TGA specimen is smaller than that of the isochronously annealed specimen at every heat-treatment temperature (673-773K). The lowest d@?/dT of R-phase transformation (0.0031%/K) was obtained for the specimen that was TGA-treated at 673K. The difference in d@?/dT of R-phase and the martensitic transformation of the TGA-treated and isochronously annealed specimen was largest at 773K and increased with increasing stress. Such behavior provides superior controllability for actuation applications.

Figure of merits of magneto-optic spatial modulators with magneto-photonic crystals

K. Takahashi,H. Takagi,K. H. Chung,K. H. Shin,H. Uchida,P. B. Lim,M. Inoue 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

LC Filter-Type Magnetoimpedance Sensors with Multilayer Film Structure

K. Tanaka,K. H. Shin,H. Uchida,M Inoue 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Evaluation of bending strength of carburized gears

Inoue, K. 대한기계학회 1995 International Forum on Advances in Mechanical Engi Vol.1 No.1

The reduction of size and weight is one of the important objectives for the development of advanced power transmission gear system. It is realized by increasing the load carrying capacity of the gears. From this point of view, this article summarizes our research on the evaluation of bending fatigue strength of carburized gears, and presents an experimental formula, which has been derived for estimating the strength from the surface and the core hardnesses and the surface residual stress, and the effect of surface treatments such as shot peening and chemical polishing on the strength enhancement of carburized gears.

MAGNETOHYDRODYNAMIC SIMULATION OF THE X2.2 SOLAR FLARE ON 2011 FEBRUARY 15. I. COMPARISON WITH THE OBSERVATIONS

Inoue, S.,Hayashi, K.,Magara, T.,Choe, G. S.,Park, Y. D. IOP Publishing 2014 The Astrophysical journal Vol.788 No.2

<P>We performed a magnetohydrodynamic (MHD) simulation using a nonlinear force-free field (NLFFF) in solar active region 11158 to clarify the dynamics of an X2.2-class solar flare. We found that the NLFFF never shows the dramatic dynamics seen in observations, i.e., it is in a stable state against the perturbations. On the other hand, the MHD simulation shows that when the strongly twisted lines are formed at close to the neutral line, which are produced via tether-cutting reconnection in the twisted lines of the NLFFF, they consequently erupt away from the solar surface via the complicated reconnection. This result supports the argument that the strongly twisted lines formed in NLFFF via tether-cutting reconnection are responsible for breaking the force balance condition of the magnetic fields in the lower solar corona. In addition to this, the dynamical evolution of these field lines reveals that at the initial stage the spatial pattern of the footpoints caused by the reconnection of the twisted lines appropriately maps the distribution of the observed two-ribbon flares. Interestingly, after the flare, the reconnected field lines convert into a structure like the post-flare loops, which is analogous to the extreme ultraviolet image taken by the Solar Dynamics Observatory. Eventually, we found that the twisted lines exceed a critical height at which the flux tube becomes unstable to the torus instability. These results illustrate the reliability of our simulation and also provide an important relationship between flare and coronal mass ejection dynamics.</P>

POSTERS / PM-011 : DIRECT ACTIVATION OF p70 S6 KINASE ( p70 ) BY MAMMALIAN TARGET OF RAPAMYCIN ( mTOR )

(K . Hara),(S . Isotani),(C . Tokunaga),(H . Inoue),(K . Yonezawa),(J . Avruch) 한국생화학분자생물학회 (구 한국생화학회) 1999 6th IUBMB SEOUL CONFERENCE Vol.- No.-