• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.233-236
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• 2002

A conceptual design of single phase high Tc superconducting (HTS) 1MVA transformer was presented in this paper. The rated voltages of each sides of the transformer are 22.9kV /6.6kV respectively. Double pancake windings of BSCCO-2223 HTS tape and the room temperature shell type core are adopted. The HTS tapes of windings are going to be cooled down to 65K by sub-cooled liquid nitrogen. A cryostat made of nonmagnetic and nonconducting material with a bore is going to be used in order to locate the core out of the cryostat. This conceptual design will be modified and a fabrication of the machine is going to be based on the presented design in this paper.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.353-353
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• 2009

It is an important task to construct a recycling society with a low damage on the environment in our century. Magnetic separation is expected to be applied for the industrial waste treatment as an important supporting technology. In the magnetic separation of dry condition, the cohesive force between particles is strong compared with that in the wet condition's magnetic separation. The use of high magnetic field by the superconducting magnet enhances the powder's magnetic substance capture ability of the magnetic separation. In this study, the POSCO's coolant sludge of hot rolled steel was used for the superconducting magnetic separation of dry condition. Cryo-cooled NB-Ti superconducting magnet with 100 mm room temperature bore and 600 mm of height was used for magnetic separator.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.210-212
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• 1996

A nonlinear optimization method for the shape optimization of actively shielded superconducting MRI magnet is presented. The presented design method can optimize both main coil and shielding coil simultaneously by setting constraints on stray field intensity at a specified distance from the magnet center. A 1 Tesla actively shielded superconducting MRI magnet, with 30cm bore diameter, is designed using the presented method.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.596-599
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• 2000

30 kinds of natural products were considered for developing natural antioxidants by improved D.O. analyzing method including simple calculation of Area Under Curve. Several natural products such as Cimicifuge Rhizoma, Epimedii Herba, Atractylodis Rhizoma Alba, Acori Graminei Rhizoma, Mori Cortex Radicis, Aurantii Nobilis Pericarpium were bore nearly same antioxidant effects compared to synthetic powerful antioxidant BHT and also expressed powerful antioxidant effect than ${\beta}-carotene$ such as Eucommiae Cortex, Cinnamomi Cortex, Angelicae Gigantis Radix, Lycii Furctus, Acanthopanacis Cortex, Sophorae Radix, Paeoniae Radix, Geranii Herba. Another method of DPPH was performed for searching natural antioxidant from natural product. Sophorae Radix, Puerariae Radix, Aurantii Nobilis Pericarpium, Atractylodis Rhizoma Alba, Acori Graminei Rhizoma, Corni Fructus, Angelicae Gigantis Radix, Paeoniae Radix were carried higher antioxidant capacity than ${\beta}-carotene$ by DPPH method.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.158-162
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• 2005

Enterobacteria, named ${\lambda}-bacteria$ isolated from fusiform fish, have strong anti-angiogenesis effect. ${\lambda}-28$ species bore higher anti-angiogenesis effect. Cultured liquid was performed salting out, dialysed and freezed dried. This sample was executed size exclusion chromatography with fraction collector. Anti-angiogenesis, cytotoxicity, and SDS-PAGE were carried out with fraction number. ${\lambda}-28$ species was lower toxicity against HUVECs and effective band was conformed with SDS-PAGE.

• Advances in pediatric surgery
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• v.15 no.2
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• pp.157-160
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• 2009

Although the incidence of esophageal atresia (EA) is higher in twins than in singletons by two to three times, EA usually affects only one member of twins. We report one pair of twins concordant for EA. A 31-year-old healthy woman bore monozygotic female twins at 36 weeks of gestation. They weighed 2,216 and 2,480 g, respectively. They had EA with distal tracheoesophageal fistula and underwent primary esophageal anastomosis on the birth day and the $2^{nd}$ day of life, respectively. Twin A also had suspicious antral obstruction and pyloroplasty was done simultaneously with esophageal repair. She needed antral web excision for continued gastric stasis one month after $1^{st}$ operation and three balloon dilatations of the esophagus. Twin B recovered uneventfully.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.7 s.262
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• pp.800-807
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• 2007

Autofrettage process is used for internal forming and sizing of cylinder designed to withstand high internal pressures. Once the tube is autofrettaged, it needs to be machined to its final dimensions both at the bore and its outer surface. This paper presents an analytical analysis and numerical analysis of machined compound cylinder using finite element code, ANSYS10.0. An analytical model for predicting the level of autofrettage following either inner, outer, or combined machining of the compound cylinder is developed for the autofrettage residual stress field is simulated by an autofrettaged pressure. The autofrettaged pressures are obtained by using trying-error method. As autofrettage percentage is 20 % and 40 %, the numerical results are found to be in almost agreement with the analytical ones. However, as autofrettage percentage is 60 %, the numerical results have a little difference with the analytical ones.

• Journal of Welding and Joining
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• v.21 no.1
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• pp.99-106
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• 2003

This research was aimed to evaluate the material degradation with various microstructures of X20CrMoV121 steel weldment by Advanced Small Punch(ASP) test. Due to the regional limitation on constitutive structures, the minimized loading ball(${\varphi}1.5mm$) and bore diameter of lower die(${\varphi}3mm$) were designed for the ASP test. The micro-hardness test was also performed to assess the mechanical properties with artificial aging heat treatment. Material degradation was estimated by ductile-brittle transition temperature(DBTT). The results obtained from the ASP test were compared with those from conventional small punch(CSP) test and CVN impact test for several weldment microstructures. It was found that the ASP test clearly showed the microstructural dependance on the material degradation in the weldment.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.967-971
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• 1998

KOMAC (KOrea Multi-purpose Accelerator Complex) is the 1 Gev, 20 ㎃ proton linac. The superconducting linac for the high energy part acceleration from 100 MeV to 1 GeV is selected as a main candidate. As is well known, the superconducting linac has advantages for high current, high energy acceleration such as a large bore size, short accelerator length, and the RF efficiency. In this energy, the velocity of proton increases from $\beta$=0.87. For the design and fabrication simplicity, the cavity $\beta$ stages are divided into 3 parts. The maximum electric field in the cavity is designed below 20 ㎹/m. In this paper the design concepts and guides for this superconducting linac are introduced.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.620-625
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• 2007

Autofrettage process is used for internal forming and sizing of cylinder designed to withstand high internal pressures. Once the tube is autofrettaged, it needs to be machined to its final dimensions both at the bore and its outer surface. This paper presents an analytical analysis and numerical analysis of machined compound cylinder using finite element code, ANSYS10.0. An analytical model for predicting the level of autofrettage following either inner, outer, or combined machining of the compound cylinder is developed for the autofrettage residual stress field is simulated by an autofrettaged pressure. The autofrettaged pressures are obtained by using trying-error method. As autofrettage percentage is 20 %, the numerical results are found to be in almost agreement with the analytical ones. However, as autofrettage percentage is 60 %, the numerical results have a little difference with the analytical ones.