• 한국식품위생안전성학회지
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• 제12권1호
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• pp.15-19
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• 1997

The stability of monascin yellow pigment isolated from Monascus purpureus was determined over a period of storage for the wide range of pH, various metal ions and antioxidants. The absorption maximum of monascin pigment was 385 nm. Monascin pigment was more stable in acid solutions than in alkaline (pH 9 and pH 11) during storage period. It was also observed the reduction of absorption was occur after 3 days storage. The stability of monascin pigment was not changed by adding the various metal ions of the concentration of 10-4 M, however, it was unstable by adding the Zn2+, Al3+ and Fe3+ of 103- M concentration. The antioxidants. BHA, BHT, cysteine and L-ascorbic acid, have no effects on the stability of monascin yellow pigment. Thus, it may be concluded that the monascin pigment is stable and useful food additives as the natural colorant except for the alkaline food and food containing the Zn2+, Al3+ and Fe3+.

• Journal of Welding and Joining
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• 제31권5호
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• pp.77-81
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• 2013

We have investigated thermal stability of the mechanical and thermal conductive properties of Cu/STS/Cu 3 layered clad metal lead frame material for a LED device package at different temperatures ranging from RT to $200^{\circ}C$. The fabricated Cu/STS/Cu clad metal has a good thermal stability for the mechanical tensile strength and thermal conductivity of the over 50 $Kg/mm^2$ to the $150^{\circ}C$ and 270 $W/m{\cdot}K$ to the $200^{\circ}C$, respectively. This clad metal lead frame material at a high temperature of $150^{\circ}C$ shows a reinforced mechanical tensile strength by 1.5 times to conventional pure copper lead frame materials and also a comparable thermal conductivity to typical copper alloy lead frame materials.

• 한국전기전자재료학회논문지
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• 제29권6호
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• pp.365-369
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• 2016

In this paper, we fabricated Cu/Mn alloy shunt resistor with low resistance and thermal stability for use of mobile electronic devices. We designed metal alloy composed of copper (Cu) and manganese (Mn) to embody in low resistance and low TCR which are conflict each other. Cu allows high electrical conductivity and Mn serves thermal stability in this Cu/Mn alloy system. We confirmed the elemental composition of the designed metal alloy system by using energy dispersive X-ray (EDX) analysis. We obtained low resistance below $10m{\Omega}$ and low temperature coefficient of resistance (TCR) below $100ppm/^{\circ}C$ from the designed Cu/Mn alloy resistor. And in order to minimize resistance change caused by alternative frequency on circuit, shape design of the metal alloy wire is performed by rolling process. Finally, we conclude that design of the metal alloy system was successfully done by alloying Cu and 3 wt% of Mn, and the Cu/Mn alloy resistor has low resistance and thermal stability.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.317.2-317.2
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• 2013

Ultrathin oxide encapsulated metal-oxide hybrid nanocatalysts have been fabricated by a soft chemical and facile route. First, SiO2 nanoparticles of 25~30 nm size have been synthesized by modified Stobber's method followed by amine functionalization. Metal nanoparticles (Ru, Rh, Pt) capped with polymer/citrate have been deposited on functionalized SiO2 and finally an ultrathin layer of TiO2 coated on surface which prevents sintering and provides high thermal stability while maximizing the metal-oxide interface for higher catalytic activity. TEM studies confirmed that 2.5 nm sized metal nanoparticles are well dispersed and distributed throughout the surface of 25 nm SiO2 nanoparticles with a 3-4 nm TiO2 ultrathin layer. The metal nanoparticles are still well exposed to outer surface, being enabled for surface characterization and catalytic activity. Even after calcination at $600^{\circ}C$, the structure and morphology of hybrid nanocatalysts remain intact confirm the high thermal stability. XPS spectra of hybrid nanocatalyst suggest the metallic states as well as their corresponding oxide states. The catalytic activity has been evaluated for high temperature CO oxidation reaction as well as photocatalytic H2 generation under solar simulation. The design of hybrid structure, high thermal stability, and better exposure of metal active sites are the key parameters for the high catalytic activity. The maximization of metal-TiO2 interface interaction has the great role in photocatalytic H2 production.

• 수산해양기술연구
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• 제50권4호
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• pp.623-632
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• 2014

In this study, the stability of fishing vessels get some change in accordance with the installation of LED luring lamp in comparison with metal halide luring lamp were investigated. Inclining test for 9.77 ton class of squid jigging and hair-tail angling vessel was performed in order to make a stability evaluation. A performance analysis of the target vessels to the stability on the basis of KST-SHIP program was evaluated. The results were as follows in this study. The stability of the fishing vessel by a metal halide such as LED and the like according to the result obtained by the inclining test is a slightly present difference, and the stability is not affected. The fishing vessel with LED lamp installed satisfies all the stability criteria specified in law and IMO rule. Compared to the metal halide LED lamp the increase of the height of the center of gravity and the initial transverse metacenter was caused. Due to the LED installation, the somewhat wider wind area of the waterline, which appears as a result, does not lead to an actual increase in rolling period. But then it is necessary to be designed on that the LED lamp shape reduces wind pressure area. Because of LED lamp installation, the GM value of vessels is increasing faster rolling cycle so causes a decrease in the sense that the crew is aboard.

• Structural Engineering and Mechanics
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• 제75권6호
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• pp.701-711
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• 2020

This papers studies nonlinear stability and post-buckling behaviors of geometrically imperfect metal foam doubly-curved shells with eccentrically stiffeners resting on elastic foundation. Metal foam is considered as porous material with uniform and non-uniform models. The doubly-curved porous shell is subjected to in-plane compressive loads as well as a transverse pressure leading to post-critical stability in nonlinear regime. The nonlinear governing equations are analytically solved with the help of Airy stress function to obtain the post-buckling load-deflection curves of the geometrically imperfect metal foam doubly-curved shell. Obtained results indicate the significance of porosity distribution, geometrical imperfection, foundation factors, stiffeners and geometrical parameters on post-buckling characteristics of porous doubly-curved shells.

• Steel and Composite Structures
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• 제10권2호
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• pp.151-168
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• 2010

The subject of the paper is an isotropic metal foam rectangular plate. Mechanical properties of metal foam vary continuously through plate of the thickness. A nonlinear hypothesis of deformation of plane cross section is formulated. The system of partial differential equations of the plate motion is derived on the basis of the Hamilton's principle. The system of equations is analytically solved by the Bubnov-Galerkin method. Numerical investigations of dynamic stability for family rectangular plates with respect analytical solution are performed. Moreover, FEM analysis and theirs comparison with results of numerical-analytical calculations are presented in figures.

• Advances in aircraft and spacecraft science
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• 제6권4호
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• pp.297-314
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• 2019

Dynamic stability of a porous metal foam nano-dimension plate on elastic substrate exposed to bi-axial time-dependent forces has been studied via a novel 3-variable plate theory. Various pore contents based on uniform and non-uniform models have been introduced. The presented plate model contains smaller number of field variables with shear deformation verification. Hamilton's principle will be utilized to deduce the governing equations. Next, the equations have been defined in the context of Mathieu-Hill equation. Correctness of presented methodology has been verified by comparison of derived results with previous data. Impacts of static and dynamical force coefficients, non-local coefficient, foundation coefficients, pore distributions and boundary edges on stability regions of metal foam nanoscale plates will be studied.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 춘계학술논문요약집
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• pp.193-194
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• 2017

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.3-6
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• 2003

This paper describes the interface stability of Ta-Mo alloy metal on $SiO_2$ Alloy was formed by co-sputtering method, and the alloy composition was varied by controlling Ta and Mo sputtering power. When the atomic composition of Ta was about 91%, the measured work function was 4.2eV that is suitable for NMOS gate. To identify interface stability between Ta-Mo alloy metal and $SiO_2$, C-V, FE-SEM(Field Emission-SEM), and XRD(X-ray diffraction) were performed on the samples annealed with rapid thermal processor between $600^{\circ}C$ and $900^{\circ}C$. Even after $900^{\circ}C$ rapid thermal annealing, excellent interface stability and electrical properties were observed. Also, thermodynamic analysis was studied to compare with experimental results.