• Journal of the Korean Ceramic Society
• /
• v.39 no.4
• /
• pp.346-351
• /
• 2002

The electrical conductivity and phase stability of $ZrO_2$ doped with $Sc_2O_3$ and $CeO_2$ were investigated in order to search for better solid electrolyte material for solid oxide fuel cell. Present study showed that $ZrO_2$ doped with $Sc_2O_3$ and $CeO_2$ exhibited no phase transition during the heat treatment up to $1350^{Circ}C∼1550^{Circ}C$ and was stable as a cubic phase in whole temperature ranges. The $ZrO_2$ doped with $Sc_2O_3$ and $CeO_2$ showed much higher electrical conductivity than YSZ in the temperature range of $300∼^{Circ}C$ and better long term stability than other sc-$ZrO_2$ based electrolyte that showed the possibility as a strong candidate electrolyte material for intermediate-or low-temperature SOFC.

• Journal of Life Science
• /
• v.27 no.2
• /
• pp.131-138
• /
• 2017

In this study, for the efficient use of the byproduct of the omija (Schizandra chinensis Baillon: SC) processing industry, the ethanol extracts of the fruit (F), seed (S), and pomace (P) of SC were prepared, and their useful bioactivities were evaluated. For F-SC, S-SC, and P-SC, the extraction yields were 28.3%, 22.1%, and 7.2%, respectively, and the polyphenol contents were 8.81, 37.22, and 9.20 mg/g, respectively. The total flavonoid content in P-SC (4.31 mg/g) was 3.5-fold higher than that in F-SC (0.76 mg/g). In an antioxidation activity assay, P-SC showed stronger radical scavenging activities against DPPH anion, ABTS cation, and nitrite and stronger reducing power activities than the other extracts. The calculated concentration required for 50% radical scavenging activity, $RC_{50}s$, of P-SC for DPPH anion, ABTS cation, and nitrite was 226.2, 192.5, and $92.5{\mu}g/ml$, respectively. In an antimicrobial activity assay, F-SC, S-SC, and P-SC showed similarly strong growth inhibitions against Bacillus subtilis and P. vulgaris at a concentration of 0.5 mg/disc. F-SC and P-SC showed 15-fold extended time in thrombin, prothrombin, and activated partial thromboplastin time assays at a concentration of 5 mg/ml. The anticoagulation activity of P-SC (2.5 mg/ml) was comparable to that of aspirin (1.5 mg/ml). Furthermore, F-SC and S-SC showed very good platelet aggregation inhibitory activities. F-SC, S-SC, and P-SC did not show significant hemolysis against human red blood cell up to a concentration of 0.5 mg/ml. These results suggest that S-SC and P-SC, both of which are byproducts of the omija processing industry, show strong potential as novel antioxidant, antimicrobial, and antithrombosis agents.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.7A
• /
• pp.748-755
• /
• 2004

In this paper, the hybrid SC/MRC technique was applied to the MC/DS-CDMA system in the Nakagami-m multi-path fading environment. The applied scheme was compared with other cases when the MRC technique was applied and then performances were analyzed. The result of analysis showed that the performance of the applied system, whose number of branches (L) for the input diversity of each carrier wave was 3 and かme selected number of branches ( Lc) was 2, was better than that of the MRC technique when the Lc of the MRC technique was 2. The performance of the applied system was lower than that of the MRC technique, then the Lc of the MRC technique was 3. However, as the fading index was lowered, which means the telecommunication environment deteriorated, the performance of the hybrid SC/MRC-(2/3) diversity technique when Lc of MRC technique was 3, was almost the same as that of the MRC technique. The hybrid SC/MRC-(2/3) diversity technique shows a similar performance to that of the MRC technique, when the Lc of the MRC technique was 4. Therefore, it was confirmed that the MC/DS-CDMA system could reduce complexity and achieve similar performance to that of the MRC by applying the hybrid SC/MRC technique, which utilized the advantages of the SC technique and high performance of the MRC scheme, rather than the MRC diversity technique that requires bit synchronization, frequency of fading, and phase synchronization for every diversity branch.

• Applied Biological Chemistry
• /
• v.46 no.1
• /
• pp.16-22
• /
• 2003

Interrelation between the antioxidative activities of 70% ethanol extracts from bran fraction of 23 kinds of colored rice and chuchung as a control were examined. Antioxidative activities were evaluated by assaying reducing power, electron-donation ability to DPPH free radical, scavenging activity of hydroxy radical $({\cdot}OH)$ generated through Fenton reaction and inhibitory activity on lipid peroxidation using linoleic acid autoxidation system, respectively. Among 24 varieties of colored rice LK 1-3-6-12-1-1 had the strongest reducing power followed by Elwee, DZ 78, Jumlalocal-1 and SC-45 in decreasing order. The electron-donating ability to DPPH radical was higher in order of HP 883-1-1-1-B-1-1, HP 833-1-3-1-1-1, LK 2-7-12-1-1 and DZ 78. The hydroxy radical scavenging activity was higher in order of DK-1, IR 1544-38-2-2-1-2-2, SC-5 and SC-45 but LK 2-7-12-1-1 had oxidative effect. In the liaoleic acid autoxidation model system, RGS No 336, LK 1B-2-1-1, LK 1B-4-12-1-1, LK 1A-2-12-1-1, LK 2-7-12-1-1 and HP 883-1-1-1-B-1-1 exhibited strong antioxidative activities but Elwee, Jumlalocal-l and SC-45 showed to have oxidative effects. The rice variety of highest pigment content was Elwee and the next were RGS-No 336, IR 1544-38-2-2-1-2-2 and SC-5 with the order of higher content. The reducing power was correlated with the quantity of the pigment in the ethanolic extract of rice bran and SC-5 showed relatively high antioxidative activity in every results of antioxidative activity tests.

• Journal of the Korean Ceramic Society
• /
• v.42 no.12 s.283
• /
• pp.787-792
• /
• 2005

A symmetrical LSCF $(La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta})\;ScSZ(89ZrO_2-10Sc_2O_3-1CeO_2)/LSCF$ electrochemical cell with a GDC (Gadolinium-Doped Ceria, $90CeO_2-10Gd_2O_3$) interlayer that was inserted between the LSCF cathode and ScSZ electrolyte was fabricated, and the electrochemical performance of these cells was evaluated. The GDC interlayer was deposited on a ScSZ electrolyte using a screen-printing technique. The GDC interlayer prevented the unfavorable solid-state reactions at the LSCF/ScSZ interfaces. The LSCF cathode on the GDC interlayer had excellent electrocatalytic performance even at $650^{\circ}C$. The Area Specific Resistance (ASR) was strongly dependent on the thickness and heat-treatment temperature of the GDC interlayer. The impedance spectra showed that the cell with a $15\~27{\mu}m$ thick GDC interlayer heat-treated at $1200^{\circ}C$ had the lowest ASR.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11b
• /
• pp.285-288
• /
• 2002

In this paper, standardization activities and trends of ISO TC 108/SC 2 (measurement and evaluation of mechanical vibration and shock as applied machines, vehicles and structures) are reviewed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11a
• /
• pp.333.2-333
• /
• 2002

In this paper, standardization activities and trends of ISO TC 108/SC 2(Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures) are reviewed.

• Journal of the Korean earth science society
• /
• v.21 no.5
• /
• pp.503-524
• /
• 2000

Intercomparisons between four kinds of data have been done to estimate the accuracy of satellite observations and model reanalysis for middle and lower tropospheric thermal state over regional oceans. The data include the Microwave Sounding Units (MSU) Channel 2 (Ch2) brightness temperatures of NOAA satellites and the vertically weighted corresponding temperature of ECMWF GCM (1980-93). The satellite data for midtropospheric temperatures are MSU2 (1980-98) in nadir direction and SC2 (1980-97) in multiple scans, and for lower tropospheric temperature SC2R (1980-97). MSU2 was derived in this study while SC2 and SC2R were described in Spencer and Christy (1992a, 1992b). Temporal correlations between the above data were high (r${\ge}$0.90) in the middle and high latitudes, but low(r${\sim}$0.65) over the low latitude and more convective regions. Their values with SC2R which included the noises due to hydrometeors and surface emission were conspicuously low. The reanalysis shows higher correlation with SC2 than with MSU2 partially because of the hydrometeors screening. SC2R in monthly climatological anomalies was more sensitive to surface thermal condition in northern hemisphere than MSU2 or SC2. The first EOF mode for the monthly mean data of MSU and ECMWF shows annual cycle over most regions except the tropics. The mode in MSU2 over the Pacific suggests the east-west dipole due to the Walker circulation, but this tendency is not clear in other data. In the first and second modes for the Ch2 anomalies over most regions, the MSU and ECMWF data commonly indicate interannual variability due to El Ni${\tilde{n}$o and La Ni${\tilde{n}$a. The substantial disagreement between observations and model reanalysis occurs over the equatorial upwelling region of the western Pacific, suggesting uncertainties in the model parameterization of atmosphere-ocean interaction.

• Review of KIISC
• /
• v.5 no.4
• /
• pp.91-101
• /
• 1995

본 학회지의 1993년 6월호에 ISO/IEC JTC1/SC27에 대한 소개를 한 이후로 매호마다 SC27에서 제정된표준 (IS 10118-1, 9798-4, 9798-3, 9798-2, 9798-1, 9796, 8372, 10116, 9797)을 소개해 왔다. 이번호에는 지난 11월 서울에서 열렸던 국제 표준화회의를 소개함으로써 SC27 표준화의 현주소, 첫번째의 소개 이후의 진척 상황, 그리고 우리나라의 활동상 등을 파악할 수 있게 하였다.

• Nuclear Engineering and Technology
• /
• v.28 no.2
• /
• pp.185-196
• /
• 1996

The purpose of this paper is to modify the ASME Code Z-Factor, which is used in the evaluation of circumferential surface crack in nuclear ferritic pipings. The ASME Code Z-Factor is a load multiplier to compensate plastic load with elasto-plastic load. The current ASME Code Z-Factor underestimates pipe maximum load. In this study, the original SC. TNP method is modified first because the original SC. TNP method has a problem that the maximum allowable load predicted from the original SC. TNP method is slightly higher than that measured from the experiment. Then the new Z-Factor is developed using the modified SC. TNP method. The desirability of both the modified SC. TNP method and the new Z-Factor is examined using the experimental results for the circumferential surface crack in pipings. The results show that (1) the modified SC. TNP method is good for predicting the circumferential surface crack behavior in pipings, and (2) the Z-Factor obtained from the modified SC. TNP method well predicts the behavior of circumferential surface crack in ferritic pipings.