• 한국세라믹학회지
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• 제55권2호
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• pp.135-139
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• 2018

The glass structure and antibacterial properties of $(65-x)ZnO-xB_2O_3-35P_2O_5$ glasses were investigated. Zinc borophosphate glasses were prepared using a conventional melt-quenching technique at $1000^{\circ}C$. Glass transition temperature and CTE were studied and the structure of zinc borophosphate glasses was evaluated by FTIR. The $Zn^{2+}$ state increase with increasing ZnO content was investigated by XPS and a single sharp Zn $2P_{3/2}$ peak was confirmed, showing that Zn $2P_{3/2}$ exists as $Zn^{2+}$. In order to to evaluate the antimicrobial activity, Escherichia coli (E. coli) was used following the Japanese Industrial Standard JIS Z 2801; the E. coli death rate was found to increase with increasing $Zn^{2+}$ content of glasses.

• 한국염색가공학회지
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• 제21권2호
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• pp.1-6
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• 2009

Recently, polyester is widely used in textile fabrics due to its application potentials in various fields. It is known that askin fabric is prepared with mainly polyester and is enjoyed with various end uses such as marine clothing, underwear, shirts, swimming suits and so on. For this purpose, color fastness should be considered with great importance during its wet processing step. In this context, vat dyes were very much attracted due to the advantage of superior fastness property. Thus, we have used indigo dye towards askin fabric dyeings and investigated corresponding properties namely, dyeing temperature, concentration of dye, reducing agent amount and alkali amount. The results showed that higher color strengths of indigo dyeing on askin fabric were obtained at $110^{\circ}C$, 8% o.w.f, 3g/l, 5g/l, respectively. The color fastness to washing was considerable generally.

• 대한한방소아과학회지
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• 제22권1호
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• pp.113-121
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• 2008

Objectives In human myeloid leukemia cells, there are no specific features of apoptosis compared with apoptosis in other cell types. Solanum nigrum L.(SNL) is a deciduous tree, which is widely distributed in Korea with reported anti-tumor, anti-inflammatory and non-specific immune-enhancing properties. Although the plant has been clinically used for treating a variety of diseases, its bioactive ingredients are unknown and its mode of action potential has never been investigated. Thus anti-tumor property of methanol extract was investigated. Methods In this study, anti-tumor property of methanol extract was investigated by determining its in vitro growth-inhibitory effects on human myeloid leukemia cells. XTT proliferation assay, DNA fragmentation, immunoblot analysis, densitometric analysis were used. Results 1. The methanol fraction of the extracts of SNL induced mitochondria-mediated apoptosis in human myeloid leukemia cells. 2. The methanol fraction exhibited relatively higher cytotoxic activity in a dose-dependent manner than chloroform, and hexane fraction. 3. Typical ladder profile of Oligonucleosomal fragments were appeared. 4. The secreted cytosolic cytochrome C level was increased by treatment of methanol fraction. Conclusions Methanol fraction of SNL is capable of inducing apoptosis in human myeloid leukemia cells.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.226-229
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• 2003

Following the successful development of practical high temperature superconducting (HTS) wires, there has been renewed activity in the development of superconducting power equipments. HTS equipments must be operated in the coolant, such as liquid nitrogen (L$N_2$) or cooled by cooler, such as GM-cryocooler to maintain the temperature below critical temperature. In this paper, dielectric strength of some insulating materials, such as epoxy, teflon, and glass fiber reinforced plastic (GFRP) in L$N_2$was measured. Surface breakdown voltage of GFRP which is basic property in design of HTS solenoid coil was measured. Epoxy is a goof insulating material but it is fragile at cryogenic temperature. The multi-layer insulating method of current lead is suggested to compensate this fragile property. It consists of teflon tape layer and epoxy layer fixed with texture. Based on these measurements, the 6.6㎸ class HTS magnet for DC reactor type high-T$_{c}$ superconducting fault current limiter (SFCL) was successfully fabricated and tested.d.

• Journal of Welding and Joining
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• 제5권4호
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• pp.12-21
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• 1987

To investigate the suitability of nitrogen gas as an internal purging gas, various properties of GTA welded joints of duplex, 316L stainless steel, Cu-Ni alloy pipe using nitrogen purging gas were evaluated with reference to onew purged with argon gas. Mechanical properties evaluated by the tensile, bending test, and hardness value of welded joints with nitrogen gas purging did not show any difference those with argon gas. General and local corrosion rates of each welded joint prepared by nitrogen gas purging also showed no difference with those prepared by argon gas. Based on the present test results it is confirmed that nitrogen is a suitable purging gas for GTA welding of stainless steels and nonferrous piping systems, which can be used at lower cost instead of argon.

• Journal of Welding and Joining
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• 제31권2호
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• pp.49-56
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• 2013

We have investigated traits of clad metals in hot-rolled clad steel plates, sensitization and mechanical properties of STS 316 steel plate and carbon steel(A516). Clad steel plates were butt-weld by SAW+SMAW, and with the time of heat treatment as the variable, heat treatment was conducted at $625^{\circ}C$, for 80, 160, 320, 640, 1280 minutes. As a way to evaluate it, sectioned weldments and external surfaces were investigated to reveal the degree of sensitization by mechanical property, etching and those of EPR test, results were compared with it. In short, the purpose of this study is suggesting some considerations in developing on-site techniques to evaluate the sensitization of stainless steels.

• 대한수학회논문집
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• 제38권4호
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• pp.993-999
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• 2023

Let A be a G-graded commutative ring with identity and M a graded A-module. Let m, n be positive integers with m > n. A proper graded submodule L of M is said to be graded (m, n)-closed if a^m_g·x_t ∈ L implies that aⁿ_g·x_t ∈ L, where a_g ∈ h(A) and x_t ∈ h(M). The aim of this paper is to explore some basic properties of these class of submodules which are a generalization of graded (m, n)-closed ideals. Also, we investigate GC^m_n - rad property for graded submodules.

• 대한수학회보
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• 제35권4호
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• pp.683-687
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• 1998

Suppose X is a subspace of $(\sum_{n=1} ^{\infty} X_n)_{c_0}$, dim $X_n<{\infty}$, which has the metric compact approximation property. It is proved that if Y is a Banach space of cotype q for some $2{\leq}1<{\infty}$ then K(X,Y) is an M-ideal in L(X,Y).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.547-548
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• 2010

• 한국염색가공학회지
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• 제13권4호
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• pp.256-263
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• 2001

Polyester fabrics were irradiated by UV produced by the low pressure mercury lamp. UV irradiation broke a C-H bond of PET fiber and caused the carbonyl groups on the fiber surfaces. Surface modification of PET fibers were accelerated by pretreatment with methanol, ethanol and acetone. The irradiated PET was dyed with basic dyes having cationic groups. The dye uptakes were proportional to irradiation times, and in inversely proportional to irradiation distances. The tensile strengths of PET fabrics decreased by UV irradiation. Washing fastness of PET dyeings were good, about 4-5 grade,andlightfastnesswerepoor, about l grade.