• Journal of Radiation Protection and Research
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• 제29권3호
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• pp.187-196
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• 2004

The health effects resulting from severe accidents of typical 1,000MWe KSNP(Korea Standard Nuclear Plant) PWR and typical 600MWe CANDU(CANada Deuterium Uranium) plants were estimated and compared. The population distribution of the site extending to 80km for both site were considered. The releaese fraction for various source term categories(STC) and core inventories were used in the estimation of the health effects risks by using the MACCS2(MELCOR Accident Consequence Code System2) code. Individuals are assumed to evacuate beyond 16km from the site. The health effects considered in this comparative study are early and cancer fatality risk, and the results are presented as CCDF(Complementary Cumulative Distribution Function) curves considering the occurrence probability of each STC's. According to the results, the early and cancer fatality risks of PHWR plants we lower than those of PWR plants. This is attributed the fact that the amount of radioactive mateials that released to the atmosphere resulting from the postulated severe accidents of PHWR plants are smaller than that of PWR plants. And, the dominating initiating event of STC that shows maximum early and cancer fatality risk is SGTR(Steam Generator Tube Rupture) for both plants. Therefore, the appropriated actions must be taken to reduce the occurrence probability and the amounts of radioactive materials released to the environment in order to protect the public for both PWR and PHWR plants.

• The Journal of the Petrological Society of Korea
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• 제7권1호
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• pp.1-14
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• 1998

Dangsanbong volcano, which is located on the coast of the western promontory of Cheju Island, occurs in such a regular pattern on the sequences which represent an excellent example of an eruptive cycle. The volcano comprises a horseshoe-shaped tuff cone and a younger nested cinder cone on the crater floor, which are overlain by a lava cap at the top of the cinder cone, and wide lava plateau in the moat between two cones and in the northern part. The volcanic sequences suggest volcanic processes that start with Surtseyan eruption, progress through Strombolian eruption and end with Hawaiian eruption, and then are followed by rock fall from sea cliff of the tuff cone and by air fall from another crater. It is thought that the eruptive environments of the tuff cone could be mainly emergent because the present cone is located on the coast, and standing body of sea water could play a great role. It is thought that the now emergent part of the tuff cone was costructed subaerially because there is no evidence of marine reworking. The emergent tuff cone is characterized by distinctive steam-explosivity that results primarily from a bulk interaction between rapidly ascending magma and external water. The sea water gets into the vent by flooding accross or through the top or breach of northern tephra cone. Dangsanbong tuff cone was constructed from Surtseyan eruption which went into with tephra finger jetting explosion in the early stage, late interspersed with continuous upruch activities, and from ultra-Surtseyan jetting explosions producting base surges in the last. When the enclosure of the vent by a long-lived tephra barrier would prevent the flooding and thus allow the vent to dry out, the phreatomagmatic activities ceased to transmit into magmatic activity of Strombolian eruption, which constructed a cinder cone on the crater floor of the tuff cone Strombolian eruption ceased when magma in the conduit gradually became depleted in gas. In the Dangsanbong volcano, the last magmatic activity was Hawaiian eruption which went into with foundation and effusion of basalt lava.

• Plant Journal
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• 제13권2호
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• pp.46-51
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• 2017

In this study, the boiler efficiency and the change of boiler combustion state with the burner operation of the uppermost layer of 870MW opposite fired coal boiler were measured. Test results showed that the boiler efficiency was high in the order of the uppermost layer simultaneous operation of the front and rear burners, the front burner, and the rear burner operation. When the front and rear burners were operated simultaneously, the heat absorption rate of water walls in the boiler furnace was uniform at four side, and the temperature deviation of the left and right steam on the convection front surface decreased. As the heat absorption rate of the boiler improved, the loss of boiler exhaust gas decreased and the coal supply amount decreased by 8 tons/hour compared to the operation of the rear burner. This will contribute not only to the reduction of fuel cost but also to the reduction of greenhouse gas emissions.

• Proceedings of the Ginseng society Conference
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• 고려인삼학회 1988년도 학술대회지
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• pp.147-150
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• 1988

Polysaccharides which show reticuloendothelial system potentiating activity in carbon clearance tests have been examined in water extracts of Panx species. From the dried roots of P. notoginseng, an active polysaccharide called sanchinan-A was isolated. The molecular weight of sanchinan-A was estimated to be 1,500,000D and the structure was determined to be $\beta$-D-(1-3-galactan), possessing branch points at positions 0-6 at which (mainly-$\alpha$-L-arabinofuranosyl and partly $\beta$-D-galactopyranosyl)-(1-6)-$\beta$-D-galacto-pyranosyl-(1-3)-$\beta$-D-galactopyranosyl side chains are attached on average, to two of three galactosyl units. From dried rhizomes of P. japonicus, several active polysaccharides were also isolated, and these structuers were also determined. From the dried roots of P. ginseng, several polysaccharides which showed strong activity were isolated. The structures of these compounds are currently under investigation. The polysaccharide fraction (non-dialyzed fraction) of the water extract of red ginseng (steam-dried roots) did not exhibit activity, while the dialyzed fraction potentiated RES. Activity disappeared, however, during the process of separation due to the presence of a substance in the fraction which stabilizes an active substance.

• Food Science and Preservation
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• 제13권1호
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• pp.108-114
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• 2006

This study was conducted to determine the volatile flavor compositions of the essential oil and the headspace of Capsella bursa-pastoris Medicus. Essential oil and headspace from the plant were extracted by simultaneous steam distillation extraction (SDE), and solid-phase microextraction(SPME) methods, respectively. Seventy-two compounds including 28 hydrocarbons, 4 aldehydes, 6 ketones, 16 alcohols, 4 esters, 8 acids, and 6 miscellaneous ones were identified in the leaf essential oil extracted by SDE method Sixty-eight compounds including 26 hydrocarbons, 2 aldehydes, 6 ketones, 17 alcohols, 4 esters, 6 acids, and 7 miscellaneous ones were identified in the root essential oil. According to the instrumental analyses the essential oil, phytol ($21.12\%$ in leaves, $20.94\%$ in roots) was the most abundant compound Alcohols, esters, and acids were main groups of the essential oil. On the other hand, thirty-eight compounds including 18 hydrocarbons, 3 aldehydes, 3 ketones, 9 alcohols, 2 esters, 3 miscellaneous ones were identified in the leaf headspace by SPME. In root headspace, thirty-three compounds including 16 hydrocarbons, 2 aldehydes, 1 ketone, 9 alcohols, 3 esten;, and 2 miscellaneous ones were identified. Hydrocarbons($44.02\%$ in leaves, $56.98\%$ in roots) were the main components of the headspace of Capsella bursa-pastoris Medicus.

• Food Science and Preservation
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• 제10권3호
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• pp.333-338
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• 2003

pH values in all samples were in the range of 5.04 to 5.32. pH of kanjang prepared with normal pressure(NPK) was higher than that of kanjang prepared with high pressure(HPK) and kanjang prepared with steam(SPK). Titratable acidity(TA) in all samples were found to be 4.26～7.72 mL. TA in HPK(5.99～6.96 mL) was lower than that in SPK(4.26～5.61 mL) and NPK(7.32 mL). Reducing sugar(RS) contents in all samples were in the range of 25.18 to 194.81 mg％. RS contents of HPK and SPK were a similar pattern and were higher than that of NPK. Major free sugars(FS) were glucose, fructose and xylose. In total FS, SPK was higher than that of NPK and HPK. Major organic acids(OA) were succinic acid, oxalic acid, tartaric acid, malic acid and citric acid. In total OA contents, SPK(40.38～76.96 mg％) was higher than that of NPK(55.85 mg％)and HPK(27.78～34.21mg％). OA contents in HPK and SPK were decreased slightly according to the heating time of whole black bean. The highest percentage of fatty acid (FA) in all samples was palmitic acid(33.28～43.51 ％ as area ％ of GC chromatogram), followed in a decreasing order by stearic acid(14.15～19.16％) and myristic acid(5.93～19.14％). The composition ratios of three FA to total FA ranged from 55.97 to 72.85＆. In all samples, there was myristic acid that was not contained in raw soybean.

• Food Science and Preservation
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• 제14권3호
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• pp.308-314
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• 2007

To investigate effects of fermentation on volatile components, we analyzed volatile organic compounds of raw and fermented Rhus verniciflua S. bark. A 50%(w/v) sugar solution was used for fermentation. Volatile organic compounds of raw and fermented Rhus verniciflua S. were extracted by the simultaneous steam distillation and extraction(SDE) method, with a mixture of n-pentane and diethylether(1:1, v/v) and analyzed by gas chromatograph-mass spectrometer. A total of 51 and 27 volatile organic compounds were detected in raw and fermented samples, respectively, and were mainly alcohols. Compounds such as ethyl acetate, 2-methyl-3-buten-2-ol, 3-methylbutanal, 1-octen-3-o1, 3-methyl-2-butanone, hexanal and pentanal were detected as the primary compounds in the raw sample. The fermented sample showed sour different volatile compounds, such as ethanol, ethyl acetate, ethyl lactate and 3-methylbutanol. Thus, a number of volatile organic compounds were synthesized after fermentation of Rhus verniciflua S. bark.

• Food Science and Preservation
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• 제22권1호
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• pp.129-133
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• 2015

The antioxidant potentials of ten kinds of medicinal plants used as natural dyeing agents were tested. Among the plant extracts and floral waters that were examined in this study, the antioxidant activities of the DPPH and ABTS radical scavengers increased with increasing amounts of the extracts. The hot-water extracts from Aphis chinensis, Caesalpinia sappan L., Rumex crispus L., and Areca catechu effectively inhibited the DPPH and ABTS radicals at concentration below 0.1 mg/mL. The floral water obtained through steam distillation from Areca catechu, Rubia akane Nakai, Coptis chinensis, and Phellodendron amurense showed relatively valid antioxidant activities. In particular, the natural colorants extracted from Rumex crispus L., Areca catechu, and Aphis chinensis effectively suppressed the photogenerated singlet oxygen induced by a photosensitizer in in-vitro assay systems. The concentrations ($IC_{50}$) of the hot-water Aphis chinensis extract required to exert a 50% reduction effect on DPPH, ABTS, and singlet oxygen were found to be 8.5, 8.0, and $210{\mu}g/mL$, respectively. The study results suggest that extracts derived from naturally occurring colorants as well as floral waters could be used as natural antioxidants in the food and health-care industries.

• Journal of Gifted/Talented Education
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• 제25권1호
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• pp.37-58
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• 2015

The purpose of this study was to investigate the characteristics of convergence education through the Delphi survey targeting 19 teaching professionals. The Delphi survey was completed three times, drawing key factors and expected outcomes which explain the characteristics of convergence education. The key factors of convergence education were classified as 'educational design', 'teachers' expertise' and 'educational environment'. Educational design focused on the qualitative characteristics of leaner's experience. Teachers' expertise was teacher's active and supportive roles in relationship with fellow teachers and learners. Educational environment was the psychological factors with which various subjects can realize convergence education. The expected outcomes were classified as 'learner's cognitive characteristics', 'leaner's affective characteristics', and 'teacher and educational system'. The expected outcomes of convergence education leads to psychological changes for learners to increase the advanced learning experiences and to pursue values of education itself. Compared to similar concepts, convergence education has some unique characteristics in which many of regular learners in educational settings and various topics are targeted. It also focuses on psychological factors of various subjects and qualitative natures of leaners' learning experience for the advanced learning. Especially, these results have significance in understanding the nature of convergence education, focusing on educational practices through teachers'perspectives.

• Korean Journal of Food Science and Technology
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• 제37권5호
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• pp.723-729
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• 2005

Volatile compounds of dropwort (Oenanthe javanica DC), crown daisy (Chrysanthemum coronarium L. var. spatiosum), and sesame (Sesamum indicum L.) were isolated by steam distillation under reduced pressure (DRP) and liquid-liquid continuous extraction (LLE). Aroma extracts of the plants were identified by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) and their antioxidant activities were evaluated in two different assays. The aroma extracts isolated from dropwort, crown daisy, and sesame inhibited the oxidation of hexanal by 25%, 95%, and 99%, respectively, for one month at the $500{\mu}g/mL$ level. They inhibited malonaldehyde formation from cod liver oil by 48%, 54%, and 29%, respectively, at the $500{\mu}g/mL$ level. Their antioxidant activities were comparable to those of the natural antioxidant, ${\alpha}-tocopherol$.