• Journal of the Korean Electrochemical Society
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• v.2 no.3
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• pp.144-149
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• 1999

The two distinct adsorption sites and transition between the under and over-potentially deposited hydrogen (UPD H and OPD H) on the polycrystalline iridium (poly-Ir) surface in the 0.2 M LiOH electrolyte have been studied using the phase-shift method. At the forward and backward scans, the UPD H peak occurs on the cyclic voltam-mogram. The transition region on the phase-shift profile or the Langmuir adsorption isotherm occurs at ca. -0.80 to -0.95 V vs. SCE. At the transition region (-0.80 to -0.95 V vs. SCE), the equilibrium constant (K) for H adsorption transits from $7.9\times10^{-2}\;to\;1.5\times10^{-4}$ and vice versa. Similarly, the standard free energy $({\Delta}G_{ads})$ of H adsorption transits from 6.3 to 21.8kJ/mol and vice versa. The UPD H and OPD H on the poly-Ir surface act as two distinguishable electroadsorbed H species. Both the UPD H peak and the transition region are attributed to the two distinct adsorption sites of the UPD H and OPD H on the poly-Ir surface.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.241-248
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• 2009

Pre-Harvest Residue Limit (PHRL) of bifenthrin during cultivation of grape was established by utilizing the dissipation curve and biological half-life of bifenthrin calculated from the analysis of 0, 1, 2, 3, 5, 7, 10, 15 days after treatment of bifenthrin. Grape sample was extracted and partitioned with acetonitrile and dichloromethane, respectively, and bifenthrin was determined with GC/ECD. Limit of quantitation (LOQ) of bifenthrin was 0.01 ng. Recoveries at two fortification levels of 0.1 and $0.5\;mg\;kg^{-1}$ were $104.08\;{\pm}\;1.24$ and $92.25\;{\pm}\;3.13%$, respectively. The biological half-lives of bifenthrin were about 21 days at standard application rate, while, 23 days at double application rate. Dissipation of bifenthrin on grape was not influenced by growth dilution effect. The PHRLs of bifenthrin were recommended as 0.60 and $0.55\;mg\;kg^{-1}$ for 10 and 5 days before harvest, respectively.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.783-790
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• 2023

The term edutech has recently been attracting attention as the convergence of education and technology is emphasized. Schools are also exploring teaching methods using edutech. The purpose of this study is to analyze the satisfaction of 210 radiology students after using Quizn Platform and the difference in satisfaction with Quizn Platform according to general characteristics. The research results are as follows. First, as a result of the satisfaction analysis according to class type, the following order was practical class, theory + practice class, and theory class. Second, the desired teaching methods among theory classes according to general characteristics were core classes (quiz solving), lecture-style classes, discussions, and discussion classes. Third, 'Quizn was used appropriately in class.' had the highest score at 4.27±0.60, and 'I am very interested in this subject.' had the lowest score at 3.98±0.74. Additionally, there was no significant difference in response to the teaching method (p>0.05). Fourth, 'Applying Quizn to class was interesting and fun' showed the highest score at 4.24±0.94, and 'Institutional support must be provided to continue using Quizn at 3.49±0.96. Additionally, there was no significant difference in satisfaction with classes according to gender and age (p>0.05). As a limitation of this study, although we investigated the satisfaction of students using Quizn, we were unable to investigate the satisfaction of instructors who interact with students. In the future, research that considers instructor satisfaction in classes using edutech should be conducted. Universities must provide institutional support and continuous interest until edutech is selected and utilized.

• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.2
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• pp.41-48
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• 1989

This paper investigates the relationship between strain hardening exponents(n) of various marine materials and fatigue crack retardation effect after applying single overload. Using the four different sheet materials, following results are obtained. (1) The fatigue crack propagation rate after applying single overload was retarded and the effects of this retardation were closely related to the strain hardening exponent. (2) The larger the strain hardening exponents were, the more were the fatigue crack retardation effects after applying single overload. (3) The considerable crack closure with the applying of a overload was observed in matrals with large strain hardening exponent. When n is smaller than 0.1, the fatigue crack retardation effects are negligible. On the contrary, when n is larger than 0.2 the fatigue crack retardation effects are significant.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.245-248
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• 2014

Trafficking of viral glycoproteins to the cell surface results in syncytium formation in baby hamster kidney (BHK) cells infected with Newcastle disease virus (NDV). An extract from the medicinal Areca catechu L plant inhibited not only syncytium formation, but also trafficking of the hemagglutinin-neuramidase (HN) glycoprotein to the cell-surface. The viral glycoprotein was processed within the endoplasmic reticulum during transit to the cell membrane. Fungal extracts showed inhibitory activities ($IC_{50}10{\mu}g/mL$) against ${\alpha}$-glucosidase. These results suggested that A. catechu L. extracts inhibited the cell-surface expression of NDV-HN glycoprotein without significantly affecting HN glycoprotein synthesis in NDV-infected BHK cells.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.358-363
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• 2014

Herbs have active components that promote the growth rate of both animals and human. The KI-180 and KI-188 calcium food formulae contain Acanthopanacis cortex, Bombysis corpus and hoelen, seaweed calcium, chlorella extract, spirulina, colostrum powder, and other natural and functional components. We evaluated the growth-promoting effects of these formulae by analyzing the weight, femur and backbone, alkaline phosphatase, osteocalcin, testosterone, insulin-like growth factor (IGF)-1, and IGF binding protein-3 (IGFBP-3) of growing rats. Growing rats administered with KI-180 and KI-188 calcium showed the increase of body weight, body length, and femur weight and length of growing rats. In addition, administration of KI-180 and KI-188 calcium increased the alkaline phosphatase activity, the levels of osteocalcin and the growth hormones IGF-1 and IGFBP-3 of growing rats. The impact of KI-180 and KI-188 calcium on the physical development of growing rats suggests that the incorporation of these food formulae in the diets of growing children may promote the physical development.

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.120-127
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• 2015

BACKGROUND: Supervised residue trials were conducted to establish pre-harvest residue limit(PHRL), a criterion to ensure the safety of the pesticide residue in the crop harvest, of amisulbrom for winter-grown cabbage in two fields. Following to application of amisulbrom on the crop, time-course study was carried out to obtain the amisulbrom dissipation of statistical significance which enabled to calculate the predicted values of PHRL. METHOD AND RESULTS: During cultivation under greenhouse condition, samples of winter-grown cabbage were collected at 0, 1, 3, 5, 7 and 10 days after amisulbrom application, and subjected to residue analysis. Analytical method was validated by recoveries ranging 93.7~100.0% as well as limit of quantitation(LOQ) of 0.04 mg/kg. Amisulbrom residues in winter-grown cabbage gradually decreased as time elapsed. The dissipation rate of the residue would be affected by intrinsic degradation along with dilution by the cabbage growth. The decay pattern was well fitted by the simple first-order kinetics. CONCLUSION: Biological half-lives of amisulbrom in winter-grown cabbage ranged 3.7~4.1 days in two field conditions. Based on the regression of amisulbrom dissipation, PHRLs of amisulbrom in winter-grown cabbage were recommended as 8.86~9.47 and 4.21~4.35 mg/kg for 10 and 5 days before harvest, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.105-110
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• 2007

Extraction characteristics of onion (Allium cepa) and the functional properties of corresponding extracts were monitored by the response surface methodology (RSM). The maximum extraction yield of 44.02% was obtained under the specific extraction conditions, such as microwave power of 143.13 W, ethanol concentration of 61.77% and extraction time of 3.39 min. The maximum electron donating ability (EDA) was found as 45.85% at the conditions of 143.55 W microwave power, 27.52% ethanol concentration and 4.86 min extraction time. The maximum inhibitory effect on tyrosinase was 65.40% at 132.29 W, 36.47% and 7.62 min. The maximum superoxide dismutase (SOD)-like activity was 69.84% under the extraction conditions of 99.41 W, 8.47% and 7.13 min. Based on superimposition of four dimensional RSM with respect to extraction yield, electron donating ability and SOD-like activity obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of 0$\sim$120 W, ethanol concentration of 70$\sim$80% and extraction time of 2$\sim$10 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.4
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• pp.451-458
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• 1984

The effects of branched chain amino acids added to a diet on changes in the body weight with or without liver, moist and dry liver weight, protein, DNA, $^3H-thymidine$ incorporation into DNA, ana mitotic index of regenerating liver were studied in partial hepatectomized rat. Experimental diet was a 14.63% casein diet supplemented with 1.49% L-leucine, 0.90% L-isoleucine and 0.98% L-Valine, and control diet was an 18.0% casein. In both diets, 2.54% nitrogen were included. Rats fed experimental diet were significantly increased body weight with or without liver 7 days, and regenerated weight of dry liver and an index of liver regeneration 5 days after partial hepatectomy. Mitotic index, contents of protein and DNA increased in regenerating liver after partial hepatectomy was higher in experimental diet group. This results suggest that branched chain amino acids have an benefitial effect on whole body as well as liver regeneration after partial hepatectomy in rat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.785-789
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• 1995

In order to optimize the batch expression of sesame oil, recovery of expressed oil(REO) from roasted and unroasted sesame seeds were observed at different temperature, pressure, pressing duration and moisture content, and relatinship between REO and effects of expression factors were analysed. REO was high at 2.5~4.5% moisture content, 30~$50^{\circ}C$ and 30~50MPa, and decreased abruptly with increasing moisture content above 4.5%. The optimum temperature, pressure, pressing duration and moisture content were $40.1^{\circ}C$, 54.4MPa, 21.7min and 1.3% for unroasted seeds and $44.4^{\circ}C$, 37.8MPa, 14.4min and 2.52% for roasted seeds, respectively. REO in optimum condition was 84.6% in unroasted seed and 81.7% in roasted seed. From the statistic analysis between effects of expression factors and REO, importance of their effects was decreased in the order of moisture content, pressure, temperature and pressing duration. And also interaction effects were high in $pressure{\times}moisture$ content, $temperature{\times}moisture$ content and temperature pressure. The multiple regression equation between REO(Y) and temperature(T), pressure(P), moisture content(M), and pressing duration(D) were as follows ; $Y=18.20$ $35.66P$＋$24.52M-4.45P^{2}-1.20TM-4.02PM-6.62M^{2},\;r^{2}=0.89$, for unrosated sesame seed, $Y=117.93$＋$16.40P-58.61M-2.75P^{2}$＋$1.79TM-1.65PM$＋$7.16M^{2},\;r^{2}$$=0.91$ for roasted sesame seed.