• Journal of the Korean Ceramic Society
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• v.29 no.2
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• pp.152-160
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• 1992

High-Tc superconductor thick films of YBa2Cu$\chi$O7-y (X=3, 3.5, 4) of which thickness varies from 100 $\mu\textrm{m}$ to 200 $\mu\textrm{m}$ were successfully prepared by plasma spraying method, and the characteristics of thick film depending on copper content and heat treatment conditions were investigated. Regardless of heat-treated temperature, the specimens with X=3 were composed of YBa2Cu$\chi$O7-y, Y2BaCuO5 and BaCuO3 phases. The specimens with X=4, however, were composed of YBa2Cu$\chi$O7-y phase at all heat treatment conditions. The specimens with X=4 composition showed the best superconducting characteristics after heat treatment at 925$^{\circ}C$, and the superconducting transition temperature with zero resistivity (Tc,zero) was 87K. The thick film lost superconductivity when the specimens were heat-treated at 950$^{\circ}C$ because of interdiffusion between superconductor elements and bond coating elements and Y2BaCuO5 phase was found was found to be main phase at the interface.

• Journal of Animal Environmental Science
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• v.5 no.3
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• pp.181-188
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• 1999

This study was carried out to investigate the effect of blowing fan for reducing heat stress in lactating dairy cows in summer. Treatment conditions were divided into 3 types ; No blow(T1), blow to oblique angle(T2) and blow to right angle(T3). Feed intake milk yield, respiration rate, rectal temperature and plasma cortisol concenration were measured to investigate the effect of hot environment on the physiological, productive responses in lactating dairy cows. The results obtained are summarized as follows: The daily milk yields were 20.47, 22.82 and 24.31kg per head in T1, T2 and T3 during experimental period, respectively. The respiration rate was significantly (p<0.05) higher in T1 than those of T2 and T3. The rectal temperature in T1(39.4$^{\circ}C$) was higher than those of T2(39.1$^{\circ}C$), (P<0.05). The plasma cortisol concentration was higher in T1 than those of T2 and T3(P<0.05). It was suggested that blowing fan installed in the pen was effective means to reduce heat stress.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.160-165
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• 2009

This study was undertaken the effect of high temperature and high humidity on protein expression and especially plasma membrane (PM) $H^{+}ATPase$ of umbel with flowers of early cultivar 'Shinsunhwang' and intermediate cultivar 'Maebsihwang' of onion (Allium cepa L.). There were no visible any difference on the protein pattern from before flowering stage to full flowering stage of two onion cultivars, however, seed set stages were revealed induced/deduced protein patterns. At day 18, protein expression pattern of the high temperature and high humidity treatments of two cultivars was significantly reduced compared to controls. Furthermore, various protein expression of the high temperature treatment was more reduced compared to high humidity treatment. PM $H^{+}ATPase$ expression of the control plants of two onion cultivars was clearly shown, but was not detectable under high temperature treatment of the two onion cultivars using western blot analysis. PM $H^{+}ATPase$ expression of the high humidity treatment was faintly detected intermediate cultivar 'Maebsihwang', not early cultivar 'Shinsunhwang'. These results indicate that protein expression pattern and PM $H^{+}ATPase$ under high temperature treatment was considered to be more damaged compared to high humidity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.3
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• pp.189-196
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• 2022

Plasma refers to an ionized gas that is often referred to as "the fourth phase of matter", following solid, liquid, and gas. Plasma has traditionally been utilized for industrial applications such as welding and neon signs, but its promise in biomedical fields such as cancer treatment and dermatology has lately been recognized. Indeed, due to its beneficial effects in promoting collagen production, improving skin tone, and eliminating harmful bacteria in the skin, plasma treatment constitutes an important target for dermatological research. In this study, a plasma device for cosmetic manufacturing based on nitrogen, the main component of the atmosphere, was designed and assembled. Moreover, nitric oxide (NO) was selected since is easier to follow and evaluate than other nitrogen plasma active species, and its contents were measured to perform a quantitative and qualitative evaluation of plasma. First, an injection method, using different proximities labeled "sinking" and "non sinking" treatments, was performed to test the most efficient plasma treatment method. As a result, it was observed that the formulation obtained by a non sinking treatment was more effective. Furthermore, toner and ampoule were selected as cosmetics formulations, and the characteristics of the formulation and changes in the injected plasma state were observed. In both formulations, the successful injection of NO plasma was 2 times higher in toner formulation than ampoule formulation, and it gradually decreased with time, having dissipated after a week. It was confirmed that the nitrogen plasma used did not affect the stability of the toner and ampoule formulations at low temperature (4 ℃), room temperature (25 ℃), and high temperature (37 ℃ and 50 ℃) conditions. The results of this study demonstrate the potential of plasma cosmetics and highlight the importance of securing the stability of the injected plasma.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.1
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• pp.59-65
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• 2024

For plasma cosmetics, it is important to ensure the long-term stability of plasma in the formulation. This study examined the suitability of containers for efficient plasma cosmetics development. By varying the surface area covered by the plasma, 4 cm², 25 cm², 75 cm², and 175 cm² containers were injected with cosmetic plasma, and the amount of nitric oxide (NO), the main active species of nitrogen plasma, was analyzed. As a result, the surface area and stability exposed to plasma tended to be inversely proportional, and it was most effective in a 4 cm² container. Furthermore, 25 mm, 40 mm, and 50 mm vials were treated with plasma, which resulted in relative long-term stability of NO at 25 mm, a smaller surface area of the container exposed to air. Water mist and stratified mist were selected as cosmetic formulations, and NO plasma was injected into the water layer to observe the changes in formulation properties and the state of the injected NO plasma. In both formulations, the amount of NO plasma injected was about 1.5 times higher in the water phase mist than in the stratified mist, and the stratified mist gradually decreased with time and was found to disappear after 3 weeks. The stability of the nitrogen plasma was studied at low temperature (4 ℃), room temperature (25 ℃), and high temperature (37 ℃, 50 ℃). As a result, it was found that the water mist did not affect the stability, but the stratified mist observed a color change in the oil phase layer. Overall, this study demonstrates the container suitability of nitrogen plasma and suggests the importance of ensuring the stability of injected nitrogen plasma in cosmetic formulations.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.1
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• pp.37-43
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• 2020

The effects of O₂ plasma pre-treatment and post-annealing conditions on the interfacial adhesion of Ti thin film and WPR dielectric were investigated using 90° peel test for fan-out wafer level packaging (FOWLP) redistribution layer (RDL) applications. Peel strength between Ti film and WPR dielectric decreased from 8.9±1.3 g/mm to 2.7±0.9 g/mm for variation of O₂ plasma pre-treatment time from 30s to 300s, which is closely related to C-O-C or C=O bonds breakage at the WPR dielectric surface due to excessive plasma pre-treatment conditions. During post-annealing at 150℃, the peel strength abruptly decreased from 0 h to 24 h, and then maintained constant until 100 h, which is also mainly due to the damage of WPR dielectric which is weak to high temperature. Therefore, the optimum plasma pre-treatment conditions on the surface of dielectric is essential to interfacial reliability of FOWLP RDL.

• Journal of Nutrition and Health
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• v.38 no.2
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• pp.117-124
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• 2005

We investigated the effects of prolonged exposure in hot environmental condition and ingestion of fluid on various physiological variables including plasma glucose, lactate, the rating of perceived exertion (RPE), and heart rate as well as golf putting performance. Six male professional golfers were voluntarily participated in three different putting trials which were separated by seven days of time interval period. Three different putting trials were conducted at either 20℃ or 32℃, or 32℃ + Fluid ingestion. Performing 32℃ + Fluid ingestion trial, all subject ingested sport drink as much as their body mass was decreased. For each experiment, all subjects were undertaken total 48 putting, which separated by four x 12 putting in four different time points (i.e., Rest, 1 hr, 2 hr, and 3 hr). Plasma glucose concentration was significantly decreased with hot ambient condition but it was almost fully recovered by fluid ingestion. Plasma lactate concentration was significantly higher when subjects were exposed in hot environmental condition, and it did not change with fluid ingestion. There was a no different in putting performance and psychological fatigue level (performed by GRID test) at any environmental conditions. The RPE, commonly used for evaluating of physical fatigue level, was significantly dropped by fluid ingestion which indicates lower physical fatigue level. In addition to this, heart rate (HR) was also significantly decreased after fluid ingestion. Based on these results, it was concluded that the ingestion of fluid during prolonged exposure in hot ambient condition decrease the degree of physical fatigue levels and heart rate, which will possibly improve the golf performance when exposed in extreme weather condition in summer. (Korean J Nutrition 38(2): 117～124, 2005)

• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.55-60
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• 2020

The recent semiconductor packaging technology is evolving into a high-performance system-in-packaging (SIP) structure, and copper-to-copper bonding process becomes an important core technology to realize SIP. Copper-to-copper bonding process faces challenges such as copper oxidation and high temperature and high pressure process conditions. In this study, the bonding interface quality of low-temperature copper-to-copper bonding using a two-step plasma treatment was investigated through quantitative bonding strength measurements. Our two-step plasma treatment formed copper nitride layer on copper surface which enables low-temperature copper bonding. The bonding strength was evaluated by the four-point bending test method and the shear test method, and the average bonding shear strength was 30.40 MPa, showing that the copper-to-copper bonding process using a two-step plasma process had excellent bonding strength.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.560-565
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• 2003

M-doped (M=Al, Ni) ZnO thermoelectric materials were fully densified at low temperatures of 800∼1,000$^{\circ}C$ and their sintering characteristics and microstructural features were investigated. Electron microscopic analysis showed that the addition of NiO promoted tile formation of solid solution and caused actively grain growth. The addition of A1$_2$O$_3$ prevented the evaporation of pure ZnO at grain boundaries and suppressed the grain growth by the formation of secondary phase. In case of the addition of A1$_2$O$_3$ together with NiO, the specimen showed an excellent microstructure and also the SEM-EBSP (Electron Back-scattered Diffraction Pattern) analysis confirmed that it shows a superior grain boundary distribution to the others specimens. These microstructural characteristics induced by the addition of A1$_2$O$_3$ together with NiO may increase the electrical conductivity by the increase in carrier concentration and decrease the thermal conductivity by the phonon scattering effect and, consequently, improve the thermoelectric property.

• Korean Journal of Metals and Materials
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• v.46 no.10
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• pp.646-651
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• 2008

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. It is essential to choose the optimum material for the process equipment handling molten salt. IN713LC is one of the candidate materials proposed for application in electrolytic reduction process. In this study, yttria-stabilized zirconia (YSZ) top coat was applied to a surface of IN713LC with an aluminized metallic bond coat by an optimized plasma spray process, and were investigated the corrosion behavior at $675^{\circ}C$ for 216 hours in the molten salt $LiCl-Li_2O$ under an oxidizing atmosphere. The as-coated and tested specimens were examined by OM, SEM/EDS and XRD, respectively. The bare superalloy reveals obvious weight loss, and the corrosion layer formed on the surface of the bare superalloy was spalled due to the rapid scale growth and thermal stress. The top coatings showed a much better hot-corrosion resistance in the presence of $LiCl-Li_2O$ molten salt when compared to those of the uncoated superalloy and the aluminized bond coatings. These coatings have been found to be beneficial for increasing to the hot-corrosion resistance of the structural materials for handling high temperature lithium molten salts.