• Progress in Superconductivity
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• v.12 no.1
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• pp.1-5
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• 2010

In this work we synthesized both MgB2 and Carbon doped MgB2 superconductor with Ag addition via high energy milling and substituent heat treatment. Heat treatments were performed at $900\;^{\circ}C$ for 30 min in flowing Ar gas. We varied amount of Ag powder. In a range of Ag powder was 0~5wt%. The effect of Ag was correlated with superconducting properties. The results show a slight decrease in critical temperature ($T_c$) and a reduction of critical current density ($J_c$) at high fields for the Ag-doped samples as compared to the un-doped samples. Reduction of $J_c$ may be due to the formation of MgAg compound.

• Progress in Superconductivity and Cryogenics
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• v.7 no.3
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• pp.29-33
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• 2005

Critical current$(I_c)$ degradation of High $T_c$ Superconducting(HTS) tapes and AC loss under mechanical load is one of the hottest issues in HTS development and application. Mechanical load reduces the critical current of superconducting wire, and the $I_c$ degradation affects the AC loss of the wire. We measured the $I_c$ degradation and AC loss under tension and bending of Bi-2223 tapes made by 'Powder-in-Tube' technique at 77K with self-field. Also, we have studied the frequency characteristics on self-field AC loss in multi-filamentary Bi-2223/Ag tape at 77K. The measurement results and discussions on the relationship between $I_c$ degradation and AC loss are presented.

• Progress in Superconductivity and Cryogenics
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• v.8 no.1
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• pp.1-4
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• 2006

The $MgB_2$ tapes with several metal powder addition were fabricated by PIT method with or without heat treatment. The $J_c$ value of $5.600A/cm^2$ and $16.000A/cm^2$ at 4.2 K and 5 T were obtained for the $MgB_2$ tape and 10 vol % of Cu added $MgB_2$ tape without heat treatment respectively. The $J_c$ value of $8.000A/cm^2$ and $35,000A/cm^2$ at 4.2 K and 5 T were obtained for the $MgB_2$ tape and 10 vol. % of Al added $MgB_2$ tape with heat treatment, respectively. The $J_c-B$ curve shows enhancement in $J_c$ under magnetic field. which suggests enhancement in workability and grain connectivity with several metal powder addition.

• The Korean Journal of Mycology
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• v.41 no.3
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• pp.181-184
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• 2013

Rhodosporidium fluviale 201-C-1 and Kluyveromyces thermotolerans 150-JE-2(1) were isolated from wild flowers in Geumsan-gun, Chungcheongnam-do and Wando-gun, Jeollanam-do, respectively. Rhodosporidium paludigenum 86-J-1 and Candida sp. 80-J-3 were also isolated from flowers in Jeju island, Korea. Characteristics for these yeasts were not reported before. Therefore, morphological and physiological characteristics for these yeasts were investigated in this study. R. fluviale 201-C-1 was halophilic asporogenous yeast and formed pseudomycelium. It also grew at $30^{\circ}C$ and pH 4.0-6.0. K. thermotolerans 150-JE-2(1) was sugar-tolerant and halotolerant asporogenous yeast. It formed pseudomycelium and showed positive urease activity. Candida sp. 80-J-3 and R. paludigenum 86-J-1 were asporogenous yeasts, and grew well in yeast extract-peptone dextrose(YPD) medium, potato-dextrose medium as well as vitamin-free medium and YPD medium containing 5% NaCl.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2133-2141
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• 1995

The thermo-mechanical fatigue tests were performed on the specimens extracted from 1.5Cr-0. 67Mo-0.33V alloy. The characteristics of thermo-mechanical fatigue crack propagation were examined and reviewed in view of fracture mechanics. The results obtained from the present study are summarized as follows : (1) The propagation characteristics of isothermal low-cycle fatigue crack are dominated by .DELTA.J$_{f}$ in case of PP waveform, and .DELTA.J$_{c}$ in case of CP waveform. (II)The propagation characteristics of thermo-mechanical fatigue crack are dominated by .DELTA.J$_{c}$ for in-phase case, and by .DELTA.J$_{c}$ for out-of-phase. The present results were in good agreement with the equation of propagation law for isothermal low-cycle fatigue crack in case of thermo-mechanical fatigue.tigue.e.

• Journal of the Korean Mathematical Society
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• v.58 no.6
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• pp.1347-1365
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• 2021

For µ = (µ₁, …, µ_t) (µ_j > 0), ξ = (z₁, …, z_t, w) ∈ ℂ^n₁ × … × ℂ^n_t × ℂ^m, define $${\Omega}({\mu},t)=\{{\xi}{\in}\mathbb{B}_{n_1}{\times}{\cdots}{\times}\mathbb{B}_{n_t}{\times}\mathbb{C}^m:{\parallel}w{\parallel}^2 where $\mathbb{B}_{n_j}$ is the unit ball in ℂ^n_j (1 ≤ j ≤ t), C(χ, µ) is a constant only depending on χ = (n₁, …, n_t) and µ = (µ₁, …, µ_t), which is a special type of generalized Cartan-Hartogs domain. We will give some sufficient and necessary conditions for the boundedness of some type of operators on L^p(Ω(µ, t), ω) (the weighted L^p space of Ω(µ, t) with weight ω, 1 < p < ∞). This result generalizes the works from certain classes of generalized complex ellipsoids to the generalized Cartan-Hartogs domain Ω(µ, t).

• Journal of the Korean Mathematical Society
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• v.36 no.6
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• pp.1047-1059
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• 1999

Let $C(X)(C_{K}(X))$ denote the hyperspace of all nonempty closed connected subsets (subcontinua) of a locally compact Haus-dorff space X with the Fell topology. We prove that the following statements are equivalent: (1) X is locally connected. (2) C(X) is locally connected,. (3) C(X) is locally connected at each $E{\in}C_{k}(X).(4) C_{k}(X)$ is locally connected.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1295-1296
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.189-190
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1427-1428
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• 2013