• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.2
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• pp.79-86
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• 2017

In this study, the flow and heat transfer characteristics of the finned annular passage were investigated numerically. The annular passage simulates co-axial geothermal heat exchanger, and fins are installed on its inner wall to reduce heat loss from the production passage (annulus) to injection passage (inner pipe). A commercial CFD program, Ansys Fluent, was used with SST $k-{\omega}$ turbulence model. The effects of the geometric parameters of the fin on the inner tube were analyzed under the periodic boundary condition. The result indicated that most parameters had a tendency to increase with an increase in the height and angle of the fin. However, it was confirmed that the Nusselt number of the inner tube on the coaxial 15, 5, 0.3 was lower than that of the smooth tube. Additionally, the Nusselt number of the inner tube exhibited a tendency of decreasing with a decrease in the spacing in Coaxial 15, $S_f$, 0.3.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.57-65
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• 2014

Spatial and temporal distributions of zooplankton were measured in an oligotrophic pumped storage-type hydroelectric reservoir which was composed of two reservoirs exchanging water daily, with water going up at night and going down during the day. Repetitive diel disturbance of the water column can be a unique feature of this reservoir system. Chl-${\alpha}$ concentration was highest in the early winter season. Phytoplankton density was lower in summer monsoon due to high flushing rate on rainy days. The zooplankton density was higher in the smaller upper reservoir possibly due to lower fish density in the upper reservoir. In the seasonal variation a time gap was observed between the phytoplankton bloom and the zooplankton bloom (particularly a rotifer, Keratella cochlearis). It is likely to that Keratella production is partially supported by heterotrophic food sources than phytoplankton. The dominance of a mixotrophic dinoflagellate (Peridinium bipes f. ocultatum) might have complicated the trophic relationship between phytoplankton and zooplankton. Our results provide some ecological information of zooplankton community in a highly disturbed alpine reservoir ecosystem relying on mostly allochthonous organic matter.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.588-592
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• 2014

Under optimized condition mild pressure in combination with specific temperature for heat treatment transform the 6-gingerol into 6-shogaol. The purpose of this study was to optimize the conditions used for heat treatment under pressure for increasing 6-shogaol content in ginger (Zingiber officinale Roscoe). A central composite experimental design was used to evaluate the effects of application temperature ($70-130^{\circ}C$) and temperature-holding time (95-265 min) on the transformation of 6-shogaol. The experimental values were shown to be in significantly good agreement with the predicted values (adjusted determination coefficient, $R^2{_{Adj}}=0.9857$). 6-Shogaol content increased as the application temperature and temperature-holding time increased. By analyzing the response surface plots, the optimum conditions of heat treatment (temperature and time) for increasing 6-shogaol content were found to be $127^{\circ}C$ and 109 min, respectively. Under these optimal conditions, the predicted 6-shogaol content was 3.98 mg/g dried ginger. The adequacy of the model equation for predicting the optimum response values was effectively verified by the validation data.

• Korean journal of food and cookery science
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• v.21 no.6 s.90
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• pp.769-775
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• 2005

In this study we isolate substances to serve as dietary resources in order to replace the female hormone. Silkworm (Bombyx mori) is one of the most attractive hosts for large-scale production of eukaryotic proteins which have been proven safe as a dietary resource. We report on the estrogenicity of a mixture of silkworm pupa and herbs (Ginseng,Ulkeum, and Hasuo) using the immature rat uterotrophic assay in vivo. Silkworm pupa aqueousextract (KW) and silkworm oil extract (KO) induced effects on the immature rat uterotrophic assay. KO showed neither positive uterotrophic response nor inhibition on E2 induced effect, while KW and MK (mixture of KW and herbs) showed both of the effects. It is concluded that ethanol extracts from silkworm might be a good, therapeutic, natural product for hormone-deficient diseases.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.307-315
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• 2016

Purpose: The central composition design was used to optimize the mixture conditions of black garlic extract. Methods: The response surface methodology (RSM) was carried out from concentration of black garlic extract ($X_1$) and the amount of the black garlic extract ($X_2$) as independent variables, and salts ($Y_1$), reducing sugars ($Y_2$), the content of total phenolic compounds ($Y_3$) and ABTS radical scavenging activity ($Y_4$) as dependent variables. We confirmed the conditions that salinity was minimized and reducing sugar, total phenolic compounds and ABTS radical scavenging activity had maximum values through the response surface analysis. Results: All results had saddle points in originally set up conditions hence, ridge analysis was carried out for narrowing the experimental area. The minimum salt concentration was 16.03% at black garlic extract concentration of $14.84^{\circ}brix$ and contents of 9.26%. Reducing sugar content had maximum of value 7.30 g/mL at $24.58^{\circ}brix$ and contents of 8.08%. Total phenolic compounds contents and ABTS radical scavenging activity had maximum values at black garlic extract concentration of 20.33 and $25.02^{\circ}brix$. The results indicate that addition of black garlic extract contributed to increased reducing sugar, phenolic compounds contents and antioxidant activity of the soy sauce, but the salt concentration was not significantly affected. Conclusion: Based on the results of RSM, the optimum ranges of addition conditions for lowering the salt concentration and, increasing the sensory and functional ability of soy sauce were as follows: black garlic extract concentration of $15-25^{\circ}brix$ and content of 7.8-9.3%.

• Resources Recycling
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• v.26 no.5
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• pp.12-21
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• 2017

Red mud generated in the alumina manufacturing process contains various valuable resources, but it is not comprehensively recycled yet causing severe environmental problems. In Korea, red mud is producing about 200,000 tons annually and most of them are landfilled or disposed. Red mud's recycling technology is also being developed in many countries, but red mud's recycling technologies are still lacking compared to the production rate. In this study, we analyzed the characteristics and the amount of red mud, and the current status and technology development trend. Red mud has shown that recycling studies are being carried out in fields such as construction, recycling, metal recovery, adsorbent, and pollution stabilization. In particular, technologies for recovering rare earths have been developed as worldwide because of their high economic value. The data analyzed in this study will be used as basic data for the further development of technologies in the future.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.210-216
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• 2009

This study was performed to compare the effects of immuno-modulating activities of Rhodiola sachalinensis A. Bor. fractionized by consecutive solvent separation. The Cytotoxicity of all fractionized extracts on human kidney cell (HEK293) was lower than crude extracts. Generally, the butanol and chloroform extracts showed less cytotoxicity on about 10.07% and 9.67% than the crude extracts. For human immune B and T cell growth, chloroform fraction showed the highest cell growth compared to the control. The secretion of cytokines (IL-6, $TNF-\alpha$) on human B and T cells were increased by adding chloroform extracts. Also, NK cell growth was significantly improved up to nearly 30% by adding the supernatant of B cell medium grown with the chloroform fraction. It was also found that chloroform fraction could yield higher nitric oxide production from macrophage than untreated control cells. Differentiation of HL-60 cells was increased up to 131.9% after treatment with chloroform fraction extracts, compared to the control. These results indicate that the chloroform fraction of R. sachalinensis have high immune activation activity than others fractions and the crude extracts, implying that this chloroform fractions could be used a new functional material.

• Food Engineering Progress
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• v.14 no.1
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• pp.65-74
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• 2010

Culture conditions of L. plantarum TJ-LP-002, the garlic resistant strain isolated from pakimchi (green onion kimchi), were investigated for the use of feed additives. Acetic acid, citric acid, lactic acid, and tartaric acid were detected in the culture supernatant, and especially the concentrations of lactic acid and acetic acid significantly increased during cultivation. The antimicrobial activity of L. plantarum TJ-LP-002 was not affected by proteases, calatase or cellulase, which showed that the antimicrobial activity might be due to the production of acids rather than proteinaceous antimicrobial substances. L. plantarum TJ-LP-002 was resistant to neomycin sulfate, spectinomycin dihydrochloride, and lincomycin hydrochloride, sensitive to streptomycin sulfate, and intermediate resistant to ampicillin trihydrate, chloramphenicol, erythromycin, tetracycline hydrochloride, and kanamycin sulfate. The optimum initial pH of medium, fermentation temperature and time for the cell growth and antibacterial activity were pH 7.0, 30${^{\circ}C}$ and 24hr, respectively. The optimal composition of culture medium for the cell growth and antimicrobial activity was 3%(w/v) glucose as a carbon source, 3%(w/v) yeast extract as a nitrogen source, and manganese sulfate and ammonium citrate as inorganic salts. The combinatorial supplementation of these inorganic salts, rather than sole addition as an inorganic salt, resulted in better antibacterial activity.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1776-1788
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• 2019

Objective: The demands for measures to improve disease resistance and productivity of livestock are increasing, as most countries prohibit the addition of antibiotics to feed. This study therefore aimed to uncover functional feed additives to help enhance livestock immunity and disease resistance, using Acanthopanax sessiliflorus fruit extract (ASF). Methods: ASF was extracted with 70% EtOH, and total polyphenolic and catechin contents were measured by the Folin-Ciocalteu and vanillin assay, respectively. The 3D4/31 porcine macrophage cells ($M{\Phi}$) were activated by phorbol 12-myristate 13-acetate (PMA), and cell survival and growth rate were measured with or without ASF treatment. Flow-cytometric analysis determined the lysosomal activity, reactive oxygen species levels (ROS), and cell cycle distribution. Nuclear factor kappa B ($NF-{\kappa}B$) and superoxide dismutase (SOD) protein expression levels were quantified by western blotting and densitometry analysis. Quantitative polymerase chain reaction was applied to measure the lipid metabolism-related genes expression level. Lastly, the antibacterial activity of 3D4/31 $M{\Phi}$ cells was evaluated by the colony forming unit assay. Results: ASF upregulated the cell viability and growth rate of 3D4/31 $M{\Phi}$, with or without PMA activation. Moreover, lysosomal activity and intracellular ROS levels were increased after ASF exposure. In addition, the antioxidant enzyme SOD2 expression levels were proportionately increased with ROS levels. Both ASF and PMA treatment resulted in upregulation of $NF-{\kappa}B$ protein, tumor necrosis factor $(TNF){\alpha}$ mRNA expression levels, lipid synthesis, and fatty acid oxidation metabolism. Interestingly, co-treatment of ASF with PMA resulted in recovery of $NF-{\kappa}B$, $TNF{\alpha}$, and lipid metabolism levels. Finally, ASF pretreatment enhanced the in vitro bactericidal activity of 3D4/31 $M{\Phi}$ against Escherichia coli. Conclusion: This study provides a novel insight into the regulation of $NF-{\kappa}B$ activity and lipid metabolism in $M{\Phi}$, and we anticipate that ASF has the potential to be effective as a feed additive to enhance livestock immunity.

• Food Science and Preservation
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• v.14 no.2
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• pp.188-193
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• 2007

The purpose of this study was to isolate lactic acid bacteria, useful in the fermentation industry from Hahyangju Nuruk. Five strains were isolated, and identified as Lactobacillus based on growth inhibition by 10% (v/v) alcohol at pH 4.0. Isolated strains were identified to species, and named Lactobacillus plantarum L-3, L. sakei L-10, and L. curvatus strains L-8, L-11, and L-12. Morphological characteristics, physiological data, carbohydrate fermentation patterns, and 16S rRNA sequence data, were all used to characterize the bacterial isolates. L. plantarum L-3 showed the highest lactic acid productivity of all isolates, but grew only poony in the presence of 10% (v/v) alcohol at pH 4.0. The other strains exhibited lower lactic acid productivity than did L. plantarum L-3 and did not grow in the presence of 10% (v/v) alcohol at pH 4.0. The optimal temperature and pH for lactic acid production were $30^{\circ}C$ and pH 6.0 7.0, respectively. The lactic acid productivity of L. plantarum L-3, L. sakei L-10 and the three L. curvatus strains L-8, L-11, and L-12 were (% v/v of culture supematant) 1.55, 1.0, 1.06, 1.0, and 0.99, respectively, at $30^{\circ}C$ and pH 6.0. While L. plantarum L-3 suffered growth inhibition in the presence of 10% (v/v) alcohol, growth of the other strains was inhibited at 8% (v/v) alcohol.