• 한국식품영양학회지
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• 제24권4호
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• pp.489-495
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• 2011

These studies were conducted to investigate the effects an herbal extract composition(MHE) containing $Hovenia$ $dulcis$ T., $Artemisa$ $capillaris$ T., $Pueraria$ $thunbergiana$ B., $Polygonatum$ $falcatum$ A., $Agastache$ $rugosa$ O., $Silybum$ $marianum$ L. and $Glycyrrhiza$ $uralensis$ F. in alcohol administered mice. Prophylactic administration of different doses of MHE(20~100 mg/kg) had beneficial actions toward alcohol degradation in acute alcohol treated mice. In addition, intraperitoneal administration of the MHE showed anti-inflammatory effects in inhibition tests of vascular permeability produced by acetic acid. MHE also reduced the concentrations of nitric oxide(NO) and tumor necrosis factor(TNF)-${\alpha}$ in macrophages that were activated by LPS. These results demonstrate that MHE possesses the potential to stimulate alcohol degradation and inhibit inflammatory effects in mice.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.327-330
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• 2004

It is shown that the hot carrier degradation due to enhanced hot holes trapping dominates PMOSFETs lifetime both in thin and thick devices. Moreover, it is found that in 0.13 ${\mu}m$ CMOSFET the PMOS lifetime under CHC (Channel Hot Carrier) stress is lower than the NMOSFET lifetime under DAHC (Drain Avalanche Hot Carrier) stress. Therefore. the interface trap generation due to enhanced hot hole injection will become a dominant degradation factor. In case of thick MOSFET, the degradation by hot carrier is confirmed using charge pumping current method and highly necessary to enhance overall device lifetime or circuit lifetime in upcoming nano-scale CMOS technology.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.840-845
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• 2017

In this paper, in order to investigate the lifetime of oil-paper insulation, specimens were artificially aged with thermal and electrical multiple stresses. Accelerated ageing factors and equivalent operating years for each aging temperatures were derived from results of tensile strengths for the aged paper specimens. Also, the evaluation for the multi-stress aged specimens were carried out through the measurement of impulse breakdown voltage at high temperature of $85^{\circ}C$. The lifetimes of the oil-paper insulations were calculated with the value of 66.7 for 1.0 mm thickness specimens and 69.7 for 1.25 mm thickness specimens throughout the analysis of impulse BD voltages using equivalent operating years, which means that dielectric strengths would not be severely decreased until the mechanical lifetime limit. Therefore, for the lifetime evaluation of the oil-paper insulation, thermal aging would be considered as a dominant factor whereas electrical degradation would be less effective.

• Journal of Pharmaceutical Investigation
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• 제2권1호
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• pp.52-57
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• 1972

There are many reports on the stability of drugs in powders and various dosage forms. The author studied on the stability of ascorbic acid mixed with talcs. From the result of this experiment, it was considered that talcs markedly accelerated oxidative degredation of ascorbic acid in powders and the acceleration rate depends on the varieties of crude talcs. Iron salts seem to be the principal factor influencing the degradation of ascorbic acid Degradation rate of ascorbic acid mixed with purified talc is significantly slower than that with the crnde talcs. The more the concetration of ascorbic acid is diluted, the faster the degradation rate and degredation rate of Ascorbic acid is the function of tme.

• Ocean and Polar Research
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• 제24권1호
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• pp.47-53
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• 2002

To evaluate the effect of reed population on the distribution and activities of microorganisms, vertical distribution of heterotrophic bacteria, degradation rate of cellulose, extracellular aminopeptidase activity (APA) and metabolic diversity based on GN2 Microlog plate were measured at two salt marsh stations in Hogok-ri, Namyang Bay, west coast of Korea. The number of heterotrophic bacteria at station 1 (reed population inhabited area) showed 2 to 6 times higher than that of station 2 (exposed area) with exception in the surface layer. Cellulose degradation rates in station 1 showed more than 50%. month-I and higher than that of station 2 (10.2 to 38.4%. $month^{-1}$). Yet the APA at two stations did not show difference except surface layer and suggested that APA might not be a significant factor in degrading marsh plant debris. Lipid class compounds, cell wall polymers and L-alanine were widely used by microorganisms. The number and activities of bacterial populations especially concerned in plant debris degradation seemed to be stimulated by the reed communities.

• 한국태양에너지학회 논문집
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• 제29권2호
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• pp.55-61
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• 2009

This paper reviews the state-of-the art in surface analysis techniques for solar coatings. For analyzing solar coatings and interfaces, surface properties were very important factor for obtaining the information related to the optical degradation processes and microstructure. Various types of analytical techniques for chemical composition, microstructure and surface topography analysis of solar coatings were discussed. In addition, the examples of solar selective coating analysis results for applications were demonstrated. Development and analysis technique of solar coating for energy conservation was felt to be necessary at this time.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권3호
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• pp.267-279
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• 2011

LEDs have been used extensively in the mobile device, automobile, and general lighting because they are semi-permanent, long life, less power consumption, reliable and environmentally friendly. In this paper, the accelerated degradation test(ADT) for a general lighting 4W LED Lamp using external converter is considered. The conditions of ADT are high temperature and high humidity. We show that its life time is log-normally distributed with same parameters under both a normal condition and an accelerated condition, and also derive an accelerated factor.

• 에너지공학
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• 제7권2호
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• pp.163-171
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• 1998

고분자 첨가물의 퇴화는 시험용액의 고온상태에서 증가된다. 합성고분자용액의 퇴화에 대해 시간에 따른 온도와 고분자 농도의 영향을 알아보기 위해 6$0^{\circ}C$, 8$0^{\circ}C$의 온도와 100, 200, 400, 600 ppm의 다양한 고분자 농도에 따라 폐회로방식으로 실험적인 연구를 하였다. 퇴화효과는 기계적 퇴화보다 온도에 더 의존적임이 밝혀졌다. 마찰계수와 레이놀즈 수의 관계는 레이놀즈 수가 5만부터 15만까지의 범위에서 레이놀즈 수가 증가함에 따라 마찰계수가 감소하고, 저온에서 마찰은 Vi가의 최대마찰저항감소 점근선에 접근한다는 것을 보인다. 일정한 유량과 온도에 대해, 높은 고분자 농도에서 퇴화효과가 더 작게 밝혀졌다. 일정한 유량과 고분자 농도에 대해서는 퇴화율이 주로 온도에 영향받는 것으로 밝혀졌다. 8$0^{\circ}C$의 온도, 100 ppm의 고분자 농도에서 4시간후에 마찰저항 감소효과가 없어졌다. 그러나, 열적퇴화는 고분자 분자들간의 결합력을 증가시켜 주는 것으로 생각되는 계면활성제 같은 추가적인 물질을 이용하여 극복할 수 있을 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권2호
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• pp.195-204
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• 2002

The objective of this study was to examine the impact of three categories of supplements on intake and diet induced difference on degradation of straw substrates. Sixteen crossbred cattle fitted with rumen cannula were randomly divided into 4 equal groups. Animals were fed on wheat straw ad libitum without any supplement except mineral mixture (control; $T_1$) or supplemented with concentrate mixture (CS; $T_2$) or green Lucerne (GLS; $T_3$) or urea-molasses block lick (ULS; $T_4$). Total dry matter intake in $T_2$, $T_3$ and $T_4$ was increased by 70, 54 and 49%, respectively compared to $T_1$ which was only 1.55 kg/100 kg B.Wt. Other than control animals, straw intake was less on $T_3$ than $T_2$ or $T_4$. In Sacco degradation of untreated and urea treated wheat or paddy straw in different treatments indicated that the supplements had a significant (p<0.01) impact on rapidly soluble (A) and insoluble but potentially degradable (B) fractions of straw. Urea treatment increased fraction-A but, provision of supplement improved fraction-B also. Effective degradation (ED) of OM was better on $T_2$. Rate of degradation (C) of OM and CWC was dependent on diet and type of straw but hemicellulose and cellulose were related to latter factor only. ED of cell wall carbohydrates (CWC) was similar in $T_2$ and $T_4$ but higher than $T_3$. CS was more effective in improving the degradation of both untreated and urea treated straw while ULS was effective on the former only. CS had more impact on superior quality straw while contrary was true with ULS. Although GLS improved intake and degradability of untreated and urea treated straws, its bulkiness affected the straw intake compared to other supplements.

• 한국물환경학회지
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• 제25권4호
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• pp.522-529
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• 2009

To supply safe drinking water to areas lacking in water supply and drainage system, such as rural area and military bases in proximity to Demilitarized Zone, effective method for treating organic contaminants such as MTBE is required. This study focuses on seeking optimal conditions for effective degradation of MTBE using a bath type ultrasound reactor. Effectiveness of MTBE degradation by ultrasound is dependent on the frequency, power, temperature, treatment volume, initial concentration, catalyst, etc. In this study the degradation rate of MTBE by ultrasound was proportional to power/unit volume ratio and removal is relatively more efficient for 0.1 mM than for 1 mM of MTBE solution. Efficiency of ultrasound treatment for 1 mM MTBE solution was enhanced under bath temperature of $30^{\circ}C$ compared to $4^{\circ}C$, but the temperature effect was negligible for 0.1 mM MTBE solution. Also for 0.1 mM MTBE solution, effect of catalyst such as $TiO_2$ and $Fe^0$ on treatment speed was negligible, and zeolite even increases the time taken for the degradation. Under these specific experimental conditions of this study, the most determinant factor for degradation rate of MTBE in solution was frequency and power of ultrasound. The results have shown that a continuous ultrasound reactor system can be used for small scale remediation of organically polluted groundwater, under optimal conditions.