• Journal of the Korean Society of Food Science and Nutrition
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• v.10 no.1
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• pp.85-91
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• 1981

The growing cells of S. aureus were fractionated along the Schmidt-Thannhauser-Schneider's technique into several fractions such as TCA(trichloroacetic acid)-soluble, lipid, nucleic acid, protein and residue fraction. They were also fractionated according to their cellular structure into Sonic-supernatant, SDS(sodium lauryl sulfate)-soluble, Formamide-soluble and Residue fraction. Fractionation was carried out by orderly treatment of the Sonic pellet with 1.0% SDS and hot$(150^{\circ}C)$ formamide, and the pellet was prepared by centrifugation of the cells sonic osillated for 20 minutes at 150 watt. Sonic-supernatant fraction contained a 91.3% of total DNA while other fractions contained less than 9.5%. SDS-soluble fraction showed a high activity of malate dehydrogenase(13.67 unit/mg protein) and which was higher 22.3 times than the activity found from unsoluble fraction. Formamide-soluble fraction prepared from SDS-undoluble pellet by using the hot formamide exhibited a clear action of reducing sugars against the Anthronesulfate, while it exhibited no clear action against the ninhydrin. However, contrastly, the residue remainnning after extraction with formamide exhibited a clear action against ninhydrin and glucosamine was detected form the hydrolysate of residue by paper chromatography. From these results it is considered that the Sonic-supernatant fraction is mainly consisted of plasmic component of the cells. Other fractions, SDS-soluble, Formamide-soluble and Residue, should be consisted of plasma membrane, lipoplysaccharide and peptidoglycan of the cell, respectively.

• Magazine of the Korea Concrete Institute
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• v.4 no.4
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• pp.67-73
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• 1992

• Journal of the Korea Construction Safety Engineering Association
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• v.3 no.4 s.10
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• pp.59-70
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• 1993

• Proceedings of the Botanical Society of Korea Conference
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• 2002.04a
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• pp.7-16
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• 2002

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.723-724
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• 2005

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.574-575
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• 2005

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.207-210
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• 1996

This paper describes the analysis of the operation of the switched snubber in order to depress the surge voltage in the MOS-FET inverter. In this paper, the N-channel MOS-FET which operates faster than the P-channel MOS-FET was used for the inverter circuit. So, the inverter and switched snubber can operate at high-frequency in the order of MHz. The cause of generating the surge voltage in the high frequency inverter has been cleared, and then how to depress the surge voltage using the switched snubber consisting of an N-channel MOS-FET has been given. Furthermore, described is the power loss within the switched snubber which is made of an N-channel MOS-FET. The inverter having the N-channel MOS-FET used as a switched snubber can drive such a low impedance load such as mega-sonic transducer for a mega-sonic studied cleaner sufficiently.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.1
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• pp.16-26
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• 2004

The objective of this study is to apply preconditioning to Wavier-Stokes equations with a turbulence model. The concept of a pseudo sonic speed was adopted. Roe's FDS was used for spatial discretization, LU-SGS scheme was used for time integration. In order to test the algorithms, the low speed flows around NACA airfoils and the flows through supersonic nozzle were calculated. The algorithm developed in the present study shows good performance in the calculations of low speed viscous flows and supersonics flows.

• Journal of the Korean Ceramic Society
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• v.29 no.4
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• pp.312-318
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• 1992

Two kinds of alumina specimens with different grain size (1 and 51 $\mu\textrm{m}$) but same density were prepared by hot-pressing. Fracture strength and fracture toughness of these specimens at low strain rate, sonic velocity, and elastic property were evaluated. Ballistic performance against Cal. 50 AP projectile was characterized by thick-backing method by using A16061-T6 reference block. Mechanical properties measured at low strain rate showed that the specimen with samll grain (SG) were better than specimen with large grain (LG). Fracture strength and fracture toughness of LG specimen were 131 MPa and 3.01 MPa{{{{ SQRT { m} }}, but those of SG specimen were 349 and 4.23, respectively. Sonic velocity and elastic properties of these specimen were similar, but bulk velocity and bulk modulus were different at amount of 4 and 9%. The tendency of ballistic performance was not consistent with the mechnaical properties at low strain rate. The ballistic performance based on quantitative efficiency revealed that the LG specimen (5.13) was ballistically better than the SG specimen (4.00) in spite of their lower mechanical properties.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.317-324
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• 2000

In this study, ten drilled shafts were constructed for evaluating the application of NDT(Non-Destructive Testing) techniques. The drilled shafts, 0.4 m in diameter and 7.0 m in length, were constructed at Namyangju site in Namyangju City. One of the shafts was constructed with no defect, and the other shafts were constructed with the defects of soft bottom, necking, bulging, cave-in and/or weak concrete. Then, these techniques were applied to the bridge foundations for studying unknown bridge foundation characteristics.