• 한국수산과학회지
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• 제50권6호
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• pp.714-720
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• 2017

Exposure to ultraviolet (UV) radiation is associated with the development of adverse effects in skin. Among the three types of UV rays, UV-B causes the most damaging effects, inducing sunburn and penetrating the outer skin, resulting in DNA mutations and skin cancer. The objective of this study was to formulate a UV-protective film by incorporating Ecklonia cava extracts. Cells covered with the film were exposed to UV-B (50, 80, and $100mJ/cm^2$). To determine the protective effects of the film, we evaluated cell viability, intracellular ROS generation, and apoptosis. We found that all E. cava extracts absorbed UV light and exhibited protective effects against UV-B-induced photodamage. Among the protective films examined in this study, that incorporating an E. cava 70% ethanol extract (70EX) formed the most effective protection against UV-B in HaCaT cells. These findings suggest that the application of film containing E. cava extract could prevent UV-B-induced photodamage, and offer protection against the detrimental effects of UV radiation, thus maintaining physiological condition.

• 한국표면공학회지
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• 제44권2호
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• pp.44-49
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• 2011

The films formed on AZ31B magnesium alloy were prepared from alkaline solution composed of potassium permanganate and sodium hydroxide. The immersion tests were carried out at the different concentration of sodium hydroxide and pre-treatment method in 5 minute. The morphology and the phase composition of the film were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion behavior of the film in 5.0% NaCl solution was evaluated using potentiodyanmic polarization. Open circuit potential in developing film was examined with time. The thin and transparent film was mainly composed of MgO and $Mg(OH)_2$. The film with the best corrosion resistance was obtained at $70^{\circ}C$ bath temperature, 1.6 M concentration of sodium hydroxide and chemical pre-treatment.

• 한국토양비료학회지
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• 제39권4호
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• pp.214-223
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• 2006

집약적으로 재배하는 시설작물의 품질과 생산성을 향상시키기 위해서는 적절한 미량원소의 관리가 필요하며, 따라서 시설재배지 토양중의 미량원소의 유효도에 대한 평가가 우선적으로 이루어져야한다. 본 연구에서는 영남지역 주요 시설재배지 토양중의 미량원소 함량을 조사하였다. 딸기 재배지 96개소, 고추재배지 66개소, 토마토 재배지 74개소, 참외 재배지 97개소, 오이 재배지 63개소 등 총 396개소의 비닐하우스 토양 시료를 채취하였고, B, Cu, Zn, Fe 및 Mn에 대하여 총 함량과 가용성 함량을 조사하였다. 가용성 함량의 경우 B는 열수로 추출하였으며 Cu, Zn, Fe, Mn은 0.1 N HCl로 추출하였다. 비닐하우스 토양중 B, Cu, Zn, Fe, Mn의 총 함량 평균값은 각각 25, 32, 74, 21,316, $420mg\;kg^{-1}$으로 조사되었다. 이들 값은 비닐하우스 주변 노지 토양중의 총 함량과 크게 다르지 않았다. 조사지역별 그리고 재배작물별로 비교하변 비닐하우스 토양중의 각 미량원소들의 총 함량은 매우 다양하게 나타났다. 가용성 B, Cu, Zn의 함량은 전체 조사 토양에 대한 평균값으로 각각 2.1, 7.5, $35mg\;kg^{-1}$으로 나타났으며, 주변 노지 경작토양에 비하여 대부분 그 함량이 높았다. 가용성 Fe와 Mn의 경우에는 전체 평균값이 각각 156 및 $146mg\;kg^{-1}$이었으며, 가용성 Fe의 함량은 주변 노지 경작토양에 비하여 그 함량이 낮았다. 조사된 시설재배 토양중의 가용성 Zn, Fe, Mn의 함량은 모든 지역에서 대부분 일반작물 재배에 적정한 수준 또는 그 이상의 과잉 수준인 것으로 나타났다. Cu의 경우 딸기, 토마토 및 오이 재배지에서는 가용성 함량이 대부분의 조사 토양에서 적정수준 이상인 것으로 나타났으며, 고추와 오이 재배지에서는 조사토양의 약 30%에서 적정함량에 미달하는 것으로 나타났다. B의 경우 딸기, 고추, 참외 재배지에서 가용성 함량이 적정수준에 미달하는 토양이 많았으며, 전체적으로 가용성 B의 함량이 과잉 수준인 토양은 다른 원소의 경우에 비하여 상대적으로 적은 것으로 조사되었다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2005년도 동계학술연구발표회 및 2차 아시안포럼
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• pp.154-155
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• 2005

Multi-layer film of $MgO/(FePt-B)_{50nm}/ MgO$ was deposited on Si(100) substrates by RF magnetron sputtering. The boron chips were uniformly placed oil tile FePt target. The boron content of thin film was found to be about 5, 10, 15, 25 and $33 at\%$ by using a CAMECA SX-51 wavelength dispersive spectroscopy (WDX). It is observed that X-ray diffraction patterns of FePt-B film by post-annealing exhibited a transformation from disordered fcc structure to ordered $Ll_0$ phase with fct structure from around $400^{\circ}C$. By adding B, annealing temperature for ordering is about $200^{\circ}C$ lower than that of pure FePt. This remarkable decrease of the annealing temperature is closely related to the high diffusivities of Fe and Pt associated with the defects caused by movements of B atoms. The maximum coercivity(Hc) for FePt films was found to be ${\~}$13 kOe after annealing at $600^{\circ}C$ for 1hr.

• 한국초전도ㆍ저온공학회논문지
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• 제15권2호
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• pp.12-15
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• 2013

The pure and carbon (C)-doped $MgB_2$ thin films were fabricated on $Al_2O_3$ (0001) substrates at a temperature of $650^{\circ}C$ by using hot-filament-assisted hybrid physical-chemical vapor deposition technique. The $T_c$ value for pure $MgB_2$ film is 38.5 K, while it is between 30 and 35 K for carbon-doped $MgB_2$ films. Expansion in c-axis lattice parameter was observed with increase in carbon doping concentration which is in contrast to carbon-doped $MgB_2$ single crystals. Significant enhancement in the critical current density was obtained for C-doped $MgB_2$ films as compared to the undoped $MgB_2$ film. This enhancement is most probably due to the incorporation of C into $MgB_2$ and the high density of grain boundaries, both help in the pinning of vortices and result in improved superconducting performance.

• 대한기계학회논문집B
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• 제27권10호
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• pp.1370-1376
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• 2003

The investigation of liquid fuel film on the cylinder liner is an essential to understand the engine-out hydrocarbon emissions formation in SI engines. In this research, two-dimensional visualization was carried out to investigate the liquid fuel film on the quartz liner in the optical engine. For this, the optical engine with hydraulic system was designed based on the commercial SI engine. The visualization was based on the laser-induced fluorescence with total reflection technique. Using a quartz liner and a special lens, only the liquid fuel film on the liner was visualized. With using this technique, the distribution of the fuel film on the cylinder liner was measured for different engine conditions and injection timing in the optical engine.

• 대한기계학회논문집B
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• 제21권2호
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• pp.294-302
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• 1997

Falling-film evaporation experiments for aqueous solution of lithium bromide (LiBr) were performed on a horizontal smooth 19.05-mm-dia copper tube. Average heat transfer coefficients were obtained with varied film Reynolds numbers, system pressures, LiBr concentrations and degrees of wall superheat. Heat transfer coefficients increase with increasing system pressure and decreasing concentration. For degrees of wall superheat, the heat transfer coefficient did not't show the distinct trend. For this experimental ranges, heat transfer coefficients showed maximum values at an optimal film Reynolds number. The results of this work were compared with pool boiling data reported previously, and it was shown that the heat transfer performance is superior to the pool boiling.

• 대한기계학회논문집B
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• 제27권1호
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• pp.17-24
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• 2003

A mathematical model of the hydrodynamic and heat transfer performances of two-phase flow (gas-liquid) in thin film region of micro channel is proposed. For the formulation of modeling, the flow of the vapor phase and the shear stress at the liquid-vapor interface are considered. In this work, disjoining pressure and capillary force which drive the liquid flow at the liquid-vapor interface in thin film region are adopted also. Using the model, the effects of the variations of channel height and heat flux on the flow and heat transfer characteristics are investigated. Results show that the influence of variation of vapor pressure on the liquid film flow is not negligible. The heat flux in thin-film region is the most important operation factor of micro cooler system.

• 대한기계학회논문집B
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• 제33권10호
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• pp.773-777
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• 2009

In this study, the strain sensing characteristics of single-wall carbon nanotubes(SWCNTs) networks were investigated to develop a film sensor for strain sensing. The SWCNTs film are formed on flexible substrates of poly(ethylene terephthalate) (PET) using spray process. In this manner we could control the transparency and obtain excellent uniformity of the networked SWCNT film. The carbon nanotube film is isotropic due to randomly oriented bundles of SWCNTs. Using experimental results it is shown that there is a nearly linear change in resistance across the film when it is subjected to tensile stress. The results presented in this study indicate the potential of such films for high sensitive transparent strain sensors on macro scale.

• 한국세라믹학회지
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• 제43권4호
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• pp.253-258
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• 2006

In the lamination process of multi-layer ceramic modules, the occurrence of delamination comes into repeatedly. To completely improve the lamination process of LTCC sheets, a binder film was introduced between the layers. The binder film did not originate the delamination until the thickness under $40{\mu}m$. After lamination, the thickness of the binder film was determined by the infilteraion of binder by the pressure, and after the bake-out, was dependent on the decomposition of binder resin. Any detectable defect was not observed in the multilayer structure with Ag inner electrodes.