• Journal of Power System Engineering
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• v.4 no.1
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• pp.13-19
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• 2000

This study was conducted for the heat transfer reduction due to the clinker formed in the furnace of the thermal power plant. The thermal properties of clinker such as thermal conductivity, specific heat, density and void fraction were measured. The thermal conductivities of the clinker were ranged $0.32-0.54W/m{\cdot}K$ and the average specific heat and the void fraction were $930J/kg{\cdot}K$ and 0.36 respectively. The thermal resistance of clinker was the greatest among the thermal resistances. It was found that the clinker reduces more than 90% of the heat transfer if the clinker is thicker than 10 cm.

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.606-613
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• 1993

This was studied about aging characteristic of AC4A/$SiC_{w}$ 10-30v/o reinforced composite. Aging hardenability was decreased $SiC_{w}$ 30% > 10% > 20%. Aging hardening of T6 treatmented composite was higher absolute value than AC4A I/M material. And this results indicated initial hardening phenomenon according to increase $SiC_{w}$ volume fraction. Reinforced effect by pressure was the same effect as before aging treatment and the best condition pressure at 75MPa. Similar to reinforced effect according to $SiC_{w}$ volume fraction was 30 % > 10 % > 20 %. In case of pressure is low, whisker is not break the same time press with base metal after wetting. After it is wetting with base metal, a part transformed or wetting part break and whisker maintain original shape or a part transformed on the otherhand, in case of pressure is high, whisker is break in same time it was not against pressure and whisker's shape is near a polygon or spherical shape.

• The Korean Journal of Mycology
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• v.45 no.3
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• pp.175-187
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• 2017

Laetiporus sulphrueus var. miniatus is widely distributed worldwide, and has commonly been used as a medicinal mushroom. In the present study, we investigated the effects of water extract and solvent fractions from the Laetiporus miniatus as possible antioxidant, anti-thrombin and anti-invasive agents against phorbol 12-myristate 13-acetate (PMA)- or thrombin-induced matrix metalloproteinase-2 (MMP-2) and MMP-9 activities. Samples were fractionated into n-hexane, $CHCl_3$, ethyl acetate, n-butanol, and water fractions, and individually analysed. The water fraction had the highest extraction yield at 34.90% (w/w), while the n-butanol fraction demonstrated the highest anti-oxidative activity at 81.44%. In the thrombin inhibitory activity test, the water fraction exhibited the highest activity at 94.64%. Even at the concentration of $40{\mu}g/mL$, evaluation of anti-proliferating activity in YD-10B cells did not reveal any cytotoxic effects. Although MMP-9 expression in YD-10B cells increased after the addition of PMA and thrombin, MMP-2 did not. Additionally, MMP-2/-9 levels in PMA-treated YD-10B cells (i.e., both mRNA expression and protein activation) were highly inhibited in the hexane and chloroform fractions. Compared with MMP-2 levels, MMP-9 mRNA expression and proteolytic activity were inhibited to a greater extent by the hexane and chloroform fractions in thrombin-treated YD-10B cells. Taken together, these results support that thrombin induces tumor invasion through MMP-2/9 and suggest that the L. miniatus may act as an effective functional food, conferring anti-oxidative, anti-thrombotic and anti-cancer activities.

• Korean Journal of Medicinal Crop Science
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• v.15 no.4
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• pp.271-275
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• 2007

Naturally occurring substances are important biomedical resources with low toxicity and ethnopharmacology-based efficacy. Four out of 45 extracts (Celastrus orbiculatus, Cercis chinensis, Stephanadra incisa, and Weigela subsessilis) prepared from the bark of Korea Forest plants exhibited more than 50% of inhibition on $TNF-{\alpha}$ production in lipopolysaccharide (LPS)-activated RAW264.7 cells at $100\;{\mu}g/m{\ell}$. In particular, potential inhibitory components of 4 extracts showed more than 50% inhibition seemed to be concentrated in methylene chloride (MC) fraction from C. orbiculatus, in ethyl acetate (EtOAc) fraction from C. chinensis and in hexane (Hx) fraction from S. incisa, whereas inhibitory activities of W. subssilis were broadly seen in non-polar solvent fractions such as Hx, MC and EtOAc. Therefore, our results suggest that extracts from C. orbiculatus, C. chinensis, S. incisa and W. subsessilis may be developed as a therapeutic remedy against $TNF-{\alpha}-mediated$ diseases such as rheumatoid arthritis or further fractionated to isolate active components having $antiTNF-{\alpha}$ inhibitory activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1009-1017
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• 2008

For the effective use of exopeptidase from squid viscera as food processing aids, the viscera of Argentina shortfin squid (Illex argentinus) were fractionated by various methods such as acetone treatment, ammonium sulfate treatment, anion exchange chromatography, and gel filtration. The positive exopeptidase fractions were obtained from the fraction II treated by cold acetone ($30{\sim}40%$, w/w), the fraction V by ammonium sulfate ($60{\sim}70%$ saturation), the fraction II (0.2 M NaCl) by anion exchange chromatography, and the fraction I ($30{\sim}50\;kDa$) by gel filtration. The specific activities of positive fractions from viscera of I llex argentinus against substrates were higher to LeuPNA than to ArgPNA. Total activity and recovery against LeuPNA of positive fraction by gel filtration were 1,867 U and 30.69%, respectively, which were the highest among those of positive fraction. The results suggested that the gel filtration chromatography method was the most efficient method for the fractionation of exopeptidase from viscera of Illex argentinus.

• Transactions of Materials Processing
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• v.14 no.8 s.80
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• pp.712-717
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• 2005

Microstructure and mechanical properties are investigated for 0.15C-1.5Mn-1.5Al TRIP aided cold rolled steels containing $0.05wt\%P$ and $0.1wt\%P$. Despite of the complete replacement of Si by Al, the TRIP steel shows tensile strength of 700MPa and total elongation of $35\%$ by addition of $0.1wt\%$ P. Tensile strength of P added TRIP steels is not only affected by the solid solution hardening but also the volume fraction of retained austenite. As P content increases from $0.05wt\%$ to $0.1wt\%$, tensile strength and volume fraction of retained austenite are increased, but elongation is decreased. The lower stability of austenite in $0.1wt\%$ P added steel is responsible for the decrease of the elongation.

• KIEAE Journal
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• v.11 no.1
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• pp.15-20
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• 2011

Computer simulation of buildings and solar energy systems is being used increasingly in energy assessments and design. For the six locations (Seoul, Incheon, Daejeon, Deagu, Gwangju and Busan) in South Korea where the global hourly solar irradiation (GHSI) is currently measured, GHSI was calculated using a comparatively simple cloud cover radiation model (CRM) and sunshine fraction radiation model (SFRM). The result was that the measured and calculated values of GHSI were similar for the six regions. Results of cloud cover and sunshine fraction models have been compared with the measured data using the coefficient of determination (R2), root-mean-square error (RMSE) and mean bias error (MBE). The strength of correlation R2 varied within similar ranges: 0.886-0.914 for CRM and 0.908-0.934 for SFRM. Average MBE for the CRM and SFRM were 6.67 and 14.02 W/m2, respectively, and average RMSE 104.36 and 92.15 W/m2. This showed that SFRM was slightly accurate and used many regions as compared to CRM for prediction of GHSI.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.229-235
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• 2004

Soy protein was hydrolyzed by 5 different pretenses and determinated antimicrobial activity of each hydrolysate. The soy protein hydrolysate treated by pretense from Aspergillus saitoi showed the highest antimicrobial activity among the protease studied and was used for further analysis. Soy protein hydrolysate was fractionated by ultrafiltration for M.W. 10,000,3,000 and 1,000. The M.W 1,000∼3,000 showed the highest antimicrobial activity. The minimum inhibition concentrations of obtained fraction were 0.5∼0.8 mg/mL for gram positive and negative microbials, and its activity was even observed after heating at 121$^{\circ}C$ for 10 min, suggesting that hydrolyzed protein having antimicrobial activity is quite heat-stable. Reverse-phase HPLC was further applied to separate the fraction and 8 peaks were found. Each 8 peaks were separated and pooled and measured antimicrobial activity. Among them, retention time of peak at 16.02 min showed the prominent antimicrobial activity.

• Journal of Life Science
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• v.26 no.5
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• pp.584-591
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• 2016

Saururus chinensis is a perennial plants, its flavonoid compound is known to exhibit anti-oxidative activity. This study was aimed to investigate the effect of Water Extract and Solvent Fractions of Saururus chinensis on antioxidant, anti-inflammatory and anti-invasive of Phorbol 12-myristate 13-acetate (PMA)-induced matrix metalloproteinase (MMP-2) and MMP-9 activities. Plant samples were fractionated into hexane, CHCl₃, ethyl acetate, butanol, and water fractions, and each of these was assayed individually. The water fraction showed the highest extraction yield at 9.25%(w/w). Anti-oxidative activity was analyzed by DPPH assay. Cell viability was detected by the MTS assay. Anti-inflammatory activity was assayed by the nitric oxide (NO) production in mouse macrophage Raw 264.7 cells. The activity and mRNA expression of MMP-2 and MMP-9 in human oral squamous carcinoma YD-10B cells were examined by zymography and RT-PCR. As results, MMP-2/-9 activation was increased in PMA induced YD-10B cells. In PMA-treated YD-10B cells, the increased mRNA expression and protein activation of MMP-2/-9 were significantly inhibited in the ethyl acetate fraction. The ethyl acetate fraction showed the highest anti-oxidative activity at 73.38%. The ethyl acetate fraction at non-cytotoxic concentrations significantly exhibited the anti-inflammatory activity of Raw 264.7 cells in dose-dependent manner. In conclusion, these findings demonstrate that the ethyl acetate fraction obtained from a chinensis water extract potentiates a promising therapeutic anti-invasive agent and, therefore, as an anti-cancer drug for cancer prevention and therapy in oral cancer.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.879-882
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• 2004

Two-phase flow exists in many industrial components. Characteristics of two-phase flow have been studied by many researchers; however, a further study of the two-phase is required for flow-induced vibration. Characteristics of two-phase flow were measured by force sensor at the end of a vertical pipe. The predominant frequency of fluctuation was obtained for various speeds of flow pattern. A correlation to slug frequency for horizontal flow was obtained by Heywood & Richardson (1979), while Legius et al (1997) for vertical flow. A coefficient based on the correlation is estimated and then compared to the existing ones. The existing empirical formulations for average void fraction were proposed by Wallis (1969), Zuber et al (1967) and Ishii (1970). In the present result, flow parameters, such as flow quality and real velocity, are evaluated with void fraction.