• Korean Journal of Medicinal Crop Science
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• v.21 no.3
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• pp.213-219
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• 2013

This study was carried out to find out the optimum method of preparation of indigo standard solution and its stability, and to investigate the indigo contents in Niram, blue dye extract, from a total of 7 indigo plants and 34 breeding lines of Persicaria tinctoria H. Gross. Proper solvent for indigo standard was dimethyl sulfoxide (DMSO), and appropriate concentration was 1 mg of indigo in 10 mL of DMSO. Absorbance value of UV/Vis Spectrophotometer at 620 nm of standard solution was changed decreasingly 12 hours after the preparation of standard solution irrespective of the storage conditions such as temperature and light. Average value of absorbance of 8-fold diluted standard solutions prepared daily during 16 days was $0.210{\pm}0.005$, indicating the powder of indigo compound was stable chemically. Calibration curve was made for quantitative analysis of indigo of 7 Niram samples, and indigo contents ranged from 0.69% to 18.76% showing relatively larger variation. Across all 34 breeding lines, the range of indigo content was from 7.9 mg to 56.4 mg per 100 g of fresh leaves, averaging 25.2 mg of indigo content and showing a 47.7% coefficient of variation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.390-393
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• 2005

In this study, examined heavy-weight floor impact sound to rahmen structure(steel reinforced concrete structure) and bearing-wall structure(box frame type structure) that have slab thickness of 4 form at a standard laboratory through noise and vibration measured. The results of ANSYS modeling of structures was predicted that the nature natural frequency increased according to change of thickness of each slab by finite element analysis, and acceleration value decreased. Rahmen structures compares with bearing-wall structure, nature frequency was predicted low. Measurement results of natural frequency and acceleration level for structures at a standard laboratory, tendency department such as ANSYS modeling appeared. Rahmen structures appeared that reduction effect is less in Acceleration level and heavy impact sound transmission level comparing with bearing-wall structure.

• Food Science of Animal Resources
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• v.23 no.1
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• pp.70-74
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• 2003

Cheese consumption in Korea has continuously increased far the last decades by industrialization and globalization. In addition, import of fresh cheese has increased from 2 tons, and 30 thousand dollars in 1991 to 20 thousand tons, and 49 million dollars in 2001. However, Korea standard for cheese differs from CODEX, and is not consistent. To investigate more proper standards for cheese, 20 natural cheeses and 17 process cheeses were obtained from market and analysed. All the cheeses except 1 soft cheese met the standard, but 'unripened cheese' was not different from 'soft cheese' in milk solid content. Natural cheese firmness showed exponential inverse relationship(R=0.8226) to moisture on a fat-free basis(MFFB) which is used for the natural cheese standard in CODEX. Therefore, it was thought appropriate to refer to CODEX standard for using textural terminology in Korea standard for natural cheese. For process cheese, milk solid cant be estimated by the analysis, and there are no merits and penalties by the classification. It was thought proper to classify the process cheese by types, such as 'Powder', 'Slice', 'Spread', and 'Portion'. Rule for 15∼34% milk solid content of products should be prepared in standard for animal products as 'Process cheese products' for the promotion of development and consumption of cheese.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.215-215
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• 2001

• Journal of the Korean Institute of Gas
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• v.20 no.3
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• pp.59-65
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• 2016

It is imperative to use suitable explosion proof equipments to prevent explosion in different gas facilities. There is no technical standard for the classification of hazardous areas though standard of explosion proof is regulated. In this study, we have adopted Industrial Standard KS to develop the methodology for the prediction of the explosion risk in the natural gas facility with low pressure using the important factors including hole size, hypothetical volume, validation of ventilation effectiveness. The applicability of the developed methodology was evaluated by the comparison with the data obtained from experiments of natural gas explosion.

• Journal of the Korean Society of Visualization
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• v.14 no.3
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• pp.46-50
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• 2016

The objective of the present study is to perform experiments for water filled cavity heated and cooled from the side at $Ra=8.5{\times}108$. This experiment can provide validation database of the standard k-${\varepsilon}$ turbulence model for single-phase turbulent natural convection which has been regarded as one of the important phenomena in nuclear safety. For the natural convection inside a cavity, temperature and velocity were obtained by thermometry and PIV (Particle Image Velocimetry) methods. These results would be used for validation of standard k-${\varepsilon}$ turbulence model.

• Advances in concrete construction
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• v.11 no.1
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• pp.19-32
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• 2021

In the present experimental study, the high performance hybrid fiber reinforced concrete (HPHFRC) is prepared using the Modified Andreasen and Andersen (A&A) particle packing model. Total of 16 trial mixes of HPHFRC with Indian standard sand (SS) and natural river sand (NS) are prepared to achieve the selection criteria (flow percent>150 and compressive strength>80 MPa). Based on the flow percent and compressive strength criteria, the selected mixes evaluated to study the effect of usage of natural river sand (NS) and the expensive Indian standard sand (SS) on the mechanical, durability, and microstructure property of designed HPHFRC. It has been found that the Modified A&A model is reliable to design the mix for HPHFRC with excellent mechanical, durability, and microstructure properties. In addition to that, a moderate difference in the mechanical and durability properties of NS contained HPHFRC and SS contained HPHFRC is found. Based on the obtained results of NS contained HPHFRC, it can be concluded that the use of natural river sand (NS) can be successfully adopted for the production of HPHFRC, resulted in a reduction of the production cost without compromising the excellent performance of HPHFRC.

• Biomedical Science Letters
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• v.9 no.3
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• pp.151-158
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• 2003

In the biological world, there are a number of ecological fights for survival between each organism such as plants, animals and microorganism In such events, an organism can use its natural bioactive products as defence agent against other organisms. Furthermore, natural bioactive products can be utilized for medicine or functional food. Recently, we investigate the effect of Monascus pigment extracted from a fungus, Monascus anke, on the alcohol metabolism and blood lipid profile. In the present study, it is observed that Monascus pigment supplemented dietary may have a hepatoprotective effect on rat's liver damage induced with $CCl_4$ . By treatment with $CCl_4$(3 times, I.P), liver damage was reduced more in the rats fed 2% Monascus pigment extract supplemented diet than those fed standard diet, based on the serum levels of alanine aminotransferase, microsomal glucose-6-phosphatse activity and hepaic malondialdehyde content. On the other hand, oxygen free radical generating enzymes, hepatic P-450 dependent aniline hydroxylase, xanthine oxidase, and oxygen free radical scavenging enzymes, hepatic glutathione S-transferase, catalase, superoxide dismutase activities were generally higher both in $CCl_4$ treated group and control fed 2% Monascus pigment extract supplemented diet than those fed standard diet. In conclusion, the rats fed 2% Monascus pigment extract supplemented diet showed more reduced liver damage than those fed standard diet, which may be due to the acceleration of oxygen free radical metabolism.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.407-412
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• 2020

A simple and reliable HPLC method was developed to determine pharmacologically standard marker compounds of Ulmus parvifolia leaves. Standard markers were characterized with neochlorogenic acid (trans-5-O-caffeoylquinic acid, 5-CQA) and chlorogenic acid (trans-3-O-caffeoylquinic acid, 3-CQA) using NMR and UPLC-QTof-MS analysis. A method for qualitative/quantitative analysis of the leaves extracts were evaluated including two compounds by using HPLC. The stability test of 30% ethanolic extracts of the leaves sample and standard markers have been evaluated for six months. However, no significant changes in the content of the marker compounds of each extract was observed during the time of investigation.

• Journal of the Korean Society of Combustion
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• v.12 no.1
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• pp.38-47
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• 2007

The diversification of import districts of natural gas is trying to prepare an increase in the demand and price. The interchangeability of natural gases should be examined prior to supply to gas appliances, although compositional differences among natural gases are not large. The object of this study is to investigate numerically the thermodynamic and transport properties as well as information on combustion of 6 natural gases. Comparing the properties of BOG1 with those of standard gas, the maximum differences of heating value, Wobbe index, air-fuel ratio, and specific heat are 10%, 4%, 10% and 5.54%, respectively. That is, the BOG1 is required careful application. However, all gases except for BOG1 show the similar properties with standard gas. Finally, the combustion information such as flame temperature and burning velocity are examined. These results will provide the useful information related to the interchangeability of various natural gases in practical combustion appliances.