• Title/Summary/Keyword: $^{211}At$

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Effect of Relative Density on the Tensile Properties of Powder Injection Molded PH 17-4 Stainless Steel (분말사출성형된 17-4 PH STS 소결체의 밀도에 따른 인장 특성)

  • 성환진;하태권;안상호;장영원
    • Journal of Powder Materials
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    • v.9 no.4
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    • pp.211-217
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    • 2002
  • It is well known that the powder injection molding(PIM) process can overcome the shape limitations of traditional powder compaction, the costs of machining, the productivity limits of isostatic pressing and slip casting, and the defect and tolerance limitations of conventional casting. Increasing demands from industry for not only the dimensional accuracy nut mechanical strength in PIMed parts have had much effort focused on the investigation of mechanical properties of mechanical strength in PIMed parts have had much effort focused on the investigation of mechanical properties of sintered parts formed with high-strength metallic powders. The 17_4 PH $10\mu{m}$ were injection-molded into flat tensile specimens. Sintering of the compacts was carried out at the various temperatures ranging from 900 to $1350^{\circ}C$. Sintering behavior of the compacts and tensile properties of sintered specimens were investigated.

Development of the Graphite-Moderated Neutron Calibration Fields Using 241Am-Be Sources in JAEA-FRS

  • Nishino, Sho;Tanimura, Yoshihiko;Ebata, Yoshiaki;Yoshizawa, Michio
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.211-215
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    • 2016
  • Background: The moderated neutron calibration fields using $^{241}Am$-Be sources and a graphite moderator have been constructed at the Facility of Radiation Standard (FRS) in the Japan Atomic Energy Agency (JAEA). Materials and Methods: The neutron spectra of the fields were evaluated by the Monte-Carlo calculations and measurements using the Bonner Multi-sphere Spectrometer. Results and Discussion: The fields have continuous neutron spectra from several MeV to thermal neutron energy, with fluence-averaged energies of 0.84 MeV and 0.60 MeV. Reference values of fluence rates and ambient/personal dose equivalent rates were determined from neutron spectra by measurements. Conclusion: Currently, the fields are available for calibration or performance test of neutron measuring instruments.

The Study for Transient Enhanced Diffusion of Indium and Its Application to μm Logic Devices

  • Lee Jun-Ha;Lee Hoong-Joo
    • Transactions on Electrical and Electronic Materials
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    • v.5 no.6
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    • pp.211-214
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    • 2004
  • We developed a new systematic calibration procedure which was applied to the calibration of the diffusivity, segregation and TED model of the indium impurity. The TED of the indium impurity has been studied using 4 different groups of experimental conditions. Although the indium is susceptible to the TED, the RTA is effective to suppress the TED effect and maintain a steep retrograde profile. Like the boron, the indium shows significant oxidationenhanced diffusion in silicon and has segregation coefficients at the $Si/SiO_2$ interface much less than 1. In contrast, however, the segregation coefficient of indium decreases as the temperature increases. The accuracy of the proposed technique is validated by SIMS data and $0.13 {\mu}m$ device characteristics such as $V_{th}$ and $Id_{sat}$ with errors less than $5 \%$ between simulation and experiment.

Physical properties with melting temperature and holding time for $YBa_{2}$$Cu_{3}$$O_{x}$ single crystal (Y$Ba_{2}$$Cu_{3}$$O_{x}$단결정의 용융온도 및 유지시간에 따른 물리적 특성 변화)

  • 박병삼;한상철;한영희;정년호;윤희중;김경진;오제명;성태현
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2003.10a
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    • pp.93-95
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    • 2003
  • YBa$_2$Cu$_3$O$_{x}$ (Y123) single crystal was grown by TSMG (top seeded melt growth) method. Physical properties of Y123 single crystal were dependent on the shape and distribution of Y2BaCuOx (Y211) in it and on the oxygenation temperature and the holding time. In this work, It was investigated to an optimal oxygenation condition and a dependence of melting temperature and holding time on physical properties. The optimal oxygenation condition was found that it was heat-treated for 30 hours at 45$0^{\circ}C$, Also it was found that the critical current density and the size of Y211 were increased with the melting temperature and the holding time.e.

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COMINIMAXNESS OF LOCAL COHOMOLOGY MODULES WITH RESPECT TO IDEALS OF DIMENSION ONE

  • Roshan-Shekalgourabi, Hajar
    • Honam Mathematical Journal
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    • v.40 no.2
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    • pp.211-218
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    • 2018
  • Let R be a commutative Noetherian ring, a be an ideal of R and M be an R-module. It is shown that if $Ext^i_R(R/a,M)$ is minimax for all $i{\leq}{\dim}\;M$, then the R-module $Ext^i_R(N,M)$ is minimax for all $i{\geq}0$ and for any finitely generated R-module N with $Supp_R(N){\subseteq}V(a)$ and dim $N{\leq}1$. As a consequence of this result we obtain that for any a-torsion R-module M that $Ext^i_R(R/a,M)$ is minimax for all $i{\leq}dim$ M, all Bass numbers and all Betti numbers of M are finite. This generalizes [8, Corollary 2.7]. Also, some equivalent conditions for the cominimaxness of local cohomology modules with respect to ideals of dimension at most one are given.

Developing Agenda for Electronic Records Long-term Preservation and Management (전자기록의 장기적 보존과 관리를 위한 아젠다 개발)

  • Lee, Kyung-Nam;Lee, So-Yeon
    • Journal of Korean Society of Archives and Records Management
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    • v.8 no.1
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    • pp.211-234
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    • 2008
  • The present study aims to develop an agenda consisted of strategies for long-term preservation of electronic records with enduring values. To do this, it has collected 19 cases of agenda reports generated from the digital preservation community at large, including those working on electronic publications and research data as well as electronic records. The study draws its conclusion by proposing an agenda encompassing 4 areas: laws and policies; research; technologies; and partnership.

A Study on the Detection Behavior of Chlorine Dioxide on Metal Oxide Sensors (금속산화물센서의 이산화염소 가스에 대한 감지거동에 관한 연구)

  • Yu, Joon-Boo;Byun, Hyung-Gi
    • Journal of Sensor Science and Technology
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    • v.29 no.3
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    • pp.211-214
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    • 2020
  • Chlorine dioxide is very effective gas for sterilization or disinfection (in manufacturing), and does not produce harmful by-products after use. However, if its concentration exceeds 10 %, it become explosive and cannot be compressed or stored. Therefore, it is necessary to measure its concentration. In this study, the concentration of chlorine dioxide with a high oxidizing strength was measured using a metal oxide sensor. The sensor was a commercially available TGS series from Figaro. The sensitivity of the sensor was inversely proportional to a low concentration of chlorine dioxide gas below 6 ppm and returned to the initial resistance at about 6 ppm. When the gas concentration reached multiples of 10 ppm, resistance of the sensor increased to several megaohms.

Effect of HF and Plasma Treated Glass Surface on Vapor Phase-Polymerized Poly(3,4-ethylenedioxythiophene) Thin Film : Part I

  • Lee, Joonwoo;Kim, Sungsoo
    • Journal of Integrative Natural Science
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    • v.6 no.4
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    • pp.211-214
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    • 2013
  • In this study, in order to investigate how consecutive treatments of glass surface with HF acid and water vapor/Ar plasma affect the quality of 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM), poly(3,4-ethylenedioxythiophene) (PEDOT) thin films were vapor phase-polymerized immediately after spin coating of FeCl3 and poly-urethane diol-mixed oxidant solution on the monolayer surfaces prepared at various treatment conditions. For the film characterization, various poweful tools were used, e.g., FE-SEM, an optical microscope, four point probe, and a contact angle analyzer. The characterization revealed that HF treatment is not desirable for the synthesis of a high quality PEDOT thin film via vapor phase polymerization method. Rather, sole treatment with plasma noticeably improved the quality of APS-SAM on glass surface. As a result, a highly dense and smooth PEDOT thin film was grown on uniform oxidant film-coated APS monolayer surface.

NUMERICAL COUPLING OF TWO SCALAR CONSERVATION LAWS BY A RKDG METHOD

  • OKHOVATI, NASRIN;IZADI, MOHAMMAD
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.23 no.3
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    • pp.211-236
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    • 2019
  • This paper is devoted to the study and investigation of the Runge-Kutta discontinuous Galerkin method for a system of differential equations consisting of two hyperbolic conservation laws. The numerical coupling flux which is used at a given interface (x = 0) is the upwind flux. Moreover, in the linear case, we derive optimal convergence rates in the $L_2$-norm, showing an error estimate of order ${\mathcal{O}}(h^{k+1})$ in domains where the exact solution is smooth; here h is the mesh width and k is the degree of the (orthogonal Legendre) polynomial functions spanning the finite element subspace. The underlying temporal discretization scheme in time is the third-order total variation diminishing Runge-Kutta scheme. We justify the advantages of the Runge-Kutta discontinuous Galerkin method in a series of numerical examples.

Asymmetric Reduction of Prochiral Ketones with Potassium 9-O-isopinocampheyloxy-9 boratabicyclo[3.3.1]nonane$^+$

  • Park, Won-Suh;Cho, Byung-Tae;Cha, Jin-Soon
    • Bulletin of the Korean Chemical Society
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    • v.8 no.3
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    • pp.211-214
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    • 1987
  • Asymmetric reduction of a series of aliphatic ketones and representative other classes of ketones with potassium 9-O-isopinocampheyloxy-9-boratabicyclo[3.3.1]non ane (K 9-O-Ipc-9-BBNH) was studied. All the ketones examined were reduced smoothly to the corresponding alcohols in THF at -$78^{\circ}C$. Thus, the reduction of 2-butanone, 3-methyl-2-butanone, 3,3-dimethyl-2-butanone, 2-octanone, and 4-phenyl-2-butanone provides 51% ee, 61% ee, 44% ee, 35% ee, and 33% ee of optical inductions, respectively. The reduction of other classes of ketones gave 52% ee for 2,2-dimethylcyclopentanone, 47% ee for acetophenone, 23% ee for 3-acetylpyridine, 50% ee for methyl benzoylformate, 4.8% ee for 2-chloroacetophenone, 30% ee for trans-4-phenyl-3-butene-2-one, and 2% ee for 4-phenyl-3-butyn-2-one. Thus, the reagent was found to be most useful in the asymmetric reduction of acyclic and cyclic aliphatic series of ketones.