• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2631-2636
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• 2008

The most components and piping of the secondary side of domestic nuclear power plants were manufactured carbon-steel and low-alloy steel. Flow accelerated corrosion leads to wall thinning (metal loss) of carbon steel components and piping exposed to the flowing water or wet steam of high temperature, pressure, and velocity. The feedwater heaters of many nuclear power plants have recently experienced sever wall thinning damage, which increases as operating time progress. Several nuclear power plants in Korea have also experienced wall thinning damage in the shell wall around the impingement baffle. This paper describes the comparisons between the numerical analysis results using the FLUENT code and the experimental results based on down-scaled experimental facility. The experiments were performed based on several types of impingement baffle plates which are installed in low pressure feedwater heater.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.482-486
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• 2013

Recently, biohydrocarbons are gathering an interest as a new bioenergy due to the versatile applicability. In the present work, a process is proposed for the recovery of lipids from Recombinant E. coli MG1655 which provides longer chain fatty acids. After the growth of the recombinant E. coli, the cells were disrupted by high pressure homogenizer for obtaining intracellular lipids and the resulting solutions were centrifuged and extracted. For the efficient cell disruption with high pressure homogenizer, the pressure higher than 5,000 psi was required. In addition, under the conditions of applied pressure 5,000 to 20,000 psi, 1~3 pass homogenizing was enough for the more than 90% cell disruption. As organic solvents for extraction of lipid, hexane/isopropyl alcohol and ethyl acetate/ethanol systems showed excellent extracting power. With these solvent systems, the 60% lipid could be recovered. Moreover it was found that the extracted lipids contained long-chain fatty acids such as $C_{12}$, $C_{14}$, $C_{16}$ and $C_{18}$.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.398-404
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• 2007

This study was performed to investigate the enhancement of anticancer activities and immuno modulatary activities from R. coreanus. by ultra high pressure extracts process. The cytotoxicity on human kidney cell (HEK293) was showed below 19.5% in adding 1.0 $mg/m{\ell}$ concentration. The anticancer activity was increased over 10% by high pressure processing in AGS and A549 cells. The immune cell growth using human immune B and T cells was improved by the high pressure extracts of Rubus coreanus in adding 1.0 $mg/m{\ell}$ concentration. The secretion of two kinds of cytokine, the IL-6 and $TNF-{\alpha}$ from human immune B and T cells were also enhanced in adding extracts by high pressure process of R. coreanus. The ultra high pressure extraction technique showed high efficiency in extracting of bioactive compound. The ultra high pressure technique could be used combined with other technique to improve the extracting rate and extracting efficiency.

• Culinary science and hospitality research
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• v.16 no.4
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• pp.274-285
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• 2010

This study attempts to develop a mass production product standardized by the application of high pressure extraction cooking(HPEC) in order to suggest a desirable direction for the development of salt contained standardized chicken stock. In our experiment on chicken stock with varying its salt content, the total free amino acid content was highest in S3, which contained 0.3% of salt In addition, when the total content of free amino acid was divided into the contents of essential amino acid, palatable amino acid, and other types of amino acid, they showed the same distribution as the total content of free amino acid. In addition, the total content of palatable amino acid was highest among the specimens. In the results of investigating the palatability of chicken stock according to salt content, saltiness increased with the increase of the salt content, but no significant difference was observed in preference for saltiness. It is believed to have come from the difference in the sensory evaluators' preference for saltiness, and it shows that the salt content has an effect on sweet taste, delicate taste, fishy smell, and color. In particular, specimen 83, which contained 0.3% of salt, showed the highest content of palatable amino acid, and the highest level of delicate taste in sensory tests, suggesting the correlation between palatable amino acid and delicate taste.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.2
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• pp.119-128
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• 2021

Background: This study assessed anticipatory dental anxiety levels among 8- to 12-year-old children based on subjective and physiological measures and their correlation. The variations in anxiety based on sex, age, temperament, and academic performance were evaluated. Methods: An observational study was conducted in 60 children recruited from the waiting room over a 6-month period. The operator recorded subjective anxiety in the children using a novel visual facial anxiety scale. The operator also noted the demographic details and child's temperament using the nine dimensions of the Thomas and Chess criteria, and graded children as "easy," "slow to warm-up," and "difficult." The academic performance of the children was graded (parental ratings) on a five-point Likert scale. Physiological variables (heartrate [HR], oxygen saturation[SpO2], and blood pressure [BP]) were recorded by another evaluator. The correlation between anxiety levels and physiological variables was also assessed. The effects of age, sex, temperament, and academic performance on anxiety were evaluated. Results: The study included 60 children aged 8-12 years, including 36 boys and 24 girls. Seventy percent of children had mild to moderate levels of pre-extraction anxiety, while 30% of children demonstrated high anxiety. A significant positive correlation was noted between anxiety levels and HR (rs = 0.477, P < 0.001⁎) and systolic BP (rs = 0.294, P < 0.05), while a significant but inverse correlation was observed with SpO2 (rs = -0.40, P < 0.05). Anxiety did not influence diastolic BP. Children with difficult temperament and poor academic performance had significantly higher anxiety. Conclusion: A high percentage (70%) of children aged 8-12 years had mild to moderate anxiety prior to the extraction procedure. Increased HR, systolic BP, and reduced SpO2 were significantly associated with high levels of anticipatory dental anxiety. Pre-extraction anxiety was significantly related to the temperament and scholastic performance.

• Geomechanics and Engineering
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• v.13 no.2
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• pp.285-300
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• 2017

Shallow coal resources are increasingly depleted, the mining has entered the deep stage. Due to "High stress, high gas, strong adsorption and low permeability" of coal seam, the gas drainage has become more difficult and the probability of coal and gas outburst accident increases. Based on the flow solid coupling theory of coal seam gas, the coupling model about stress and gas seepage of coal seam was set up by solid module and Darcy module in Comsol Multiphysics. The gas extraction effects were researched after applying hydraulic technology to increase permeability. The results showed that the effective influence radius increases with the expanded borehole radius and drainage time, decreases with initial gas pressure. The relationship between the effective influence radius and various factors presents in the form: $y=a+{\frac{b}{\left(1+{(\frac{x}{x_0})^p}\right)}}$. The effective influence radius with multiple boreholes is obviously larger than that of the single hole. According to the actual coal seam and gas geological conditions, appropriate layout way was selected to achieve the best effect. The field application results are consistent with the simulation results. It is found that the horizontal stress plays a very important role in coal seam drainage effect. The stress distribution change around the drilling hole will lead to the changes in porosity of coal seam, further resulting in permeability evolution and finally gas pressure distribution varies.

• 한국약용작물학회:학술대회논문집
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• 2011.04a
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• pp.386-387
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• 2011

• 한국가스학회:학술대회논문집
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• 2003.10a
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• pp.157-163
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• 2003

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.194-195
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• 2008

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.181-187
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• 2012

Grifola frondosa has been used as an herbal medicine for the treatment of cancer, diabetes mellitus and high blood pressure. In this study, functional polysaccharide was obtained from Grifola frondosa using four different extraction methods: hot water(HwFP), homogenize(HgFP), acid(AcFP), and alkali(AlFP) extraction methods. The effects of these extracts on KB and HepG2 cell lines were then examined for any anti-cancer activity. Alkaline extraction produced a yield of 0.175% and the total sugar content of the extract was 54.97%. We were able to confirm that the polysaccharide extracts from the mushroom produce an anti-cancer effect. The cytotoxicity of AlFP and AcFP against HepG2 cells were 22.86% and 28.88%, respectively, and the cytotoxicity of AlFP against the KB cell lines was 47.76% at a concentration of 1,000 ${\mu}g/m{\ell}$. Therefore, these results suggest that the optimum method for extracting functional polysaccharides from G. frondosa is the alkali extraction method.