• Progress in Superconductivity
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• v.3 no.1
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• pp.130-133
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• 2001

A multifilamentary Bi-2223 HTS tape for superconducting power applications was studied through the fabrication of 250-meter long tapes by the PIT(powder in tube) process. To fabricate continuous long wire, a drawing machine, a two-drum bull block and a rolled tape winding machine were developed. Especially, 250-meter long tapes were heat treated in the shape of pancake coil to reduce the heat affect zone and to achieve the high critical current. Engineering critical current density was improved through both the enhancements of critical current density by control of thermal process and the increase of filling factor by using thin Ag alloy sheath tubes less than 1.5 mm in thickness. We have made successfully 250-meter long 37 filamentary tapes with high filling factor up to 31 % employing the modified drawing and rolling technique. The critical current of 250-meter long tapes with pancake coil type was measured by transport method at self-field up to 250 gauss of center field. The measured values, based on the transport critical current at self-field, $I_{c}$ -B characteristics and magnetic field analysis, are 34 A of I$_{c}$ and 4.0 $kA/\textrm{cm}^2$ of $J_{e}$ at 250 m, 77 K, and 0 T. We also have achieved the 56 A of I$_{c}$ and 7.0 $0 kA/\textrm{cm}^2$ of$ J_{e}$ in short tapes at 77K, self-field, and 1$mutextrm{V}$/cm.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.571-578
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• 2016

Recently, review on viability of various industrial by product and natural materials as raw material for concrete has been actively done in aspect of environment-friendly issue and depletion of natural resource. This study conducted fundamental study on the possibility of utilizing mud flat as admixture and filling material for concrete. First, chemical analysis on the viability of mud flat as admixture was done and the researchers compared it with the substance of fly ash and blast furnace slag. According to the result, substance content was proven to be inadequate. In addition, as the replacement rate of mud flat increased, compressive strength and tensile strength decreased. According to the estimated result of chemical substance analysis, possibility of utilizing mud flat as admixture was low. According to the result of experiment done as filling material, 10% ~ 30% replacement rate of mud flat manifested more than 8 Mpa of compressive strength of block which may be utilized for secondary product. However, additional experiment such as making block is required afterward. According to the result of flow experiment, as the replacement rate of mud flat increased, flow value decreased, and through chloride content analysis test, it was proven that mud flat is inappropriate to be applied as steel beam using structure since it has high content of sodium. It may be utilized as products that does not use steel beam such as internal brick.

• The Korean Journal of Petroleum Geology
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• v.1 no.1 s.1
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• pp.15-27
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• 1993

Seismic reflection profiles from the eastern continental margin of Korea delineate three major Neogene sedimentary basins perched on the shelf and slope regions: Pohang-Youngduk, Mukho and Hupo basins. The stratigraphic and structural analyses demonstrate that the formation and filling of these basins were intimately controlled by two phases of regional tectonism: transtensional and subsequent contractional deformations. In the Oligocene to Early Miocene, back-arc opening of the East Sea induced extensional shear deformation with dextral strike-slip movement along right-stepping Hupo and Yangsan faults. During the transtensional deformation, the Pohang-Youngduk Basin was formed by pull-apart opening between two strike-slip faults; in the northern part, block faulting caused to form the Mukho Basin between basement highs. As a result of the back-arc closure, the stress field was inverted into compression at the end of the Middle Miocene. Under the compressive regime, two episodes (Late Miocene and Early Pliocene) of regional deformation led to the destruction and partial uplift of the basin-filling sequences. In particular, during the second episode of compressive deformation, the Hupo fault was reactivated with an oblique-slip sense, which resulted in an opening of the Hupo Basin as a half-graben on the downthrown fault block.

• Journal of the Korean Geotechnical Society
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• v.20 no.1
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• pp.101-108
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• 2004

For the last 30 years, the use of EPS as a lightweight filling material has grown significantly throughout the world. The fields of applying EPS block have also increased. The most representative example in geotechnical applications is using EPS block as a compressible inclusion that causes the reduction of static earth pressure on earth-retaining wall, bridge abutment and pipes. EPS blocks have a good workability by its lightweight characteristic and a uniform engineering property with the change of its density. Also EPS blocks have best material property as a compressible inclusion. This paper analyzes that the compressible inclusion function of EPS causes the reduction of static earth pressure on retaining wall and concrete box culvert. A series of in-situ tests were conducted to evaluate the reduction of static earth pressure using EPS inclusion. Based on in-situ test, it is found that the magnitude of static earth pressure was reduced to about 20% for the retaining wall and about 45∼53% for the box culvert compared with theoretical active earth pressure.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.311-320
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• 1996

If root and resection is done during surgical endodontic treatment, newly exposed dentinal tubules form pathways between the canal and the peripheral tissue. Nd : YAG laser was used to block this phenomenon, and its effect was studied with dye penetration and SEM techniques. 40 intact single rooted teeth were divided into 4 groups(10 each) : control group and test groups, in which retrograde cavity surface, cutting surface, retrograde cavity surface & cutting surface were treated with laser(1 watt 15pps) and finally retrograde filling with IRM was conducted. After that, they were stained with 2 % methylene blue, sectioned and evaluated by the maximum infiltration depth. And to observe surface change, they were prepared for SEM. The results were as follows ; 1. All experimental groups showed microleakage with variation in amount. 2. The 2nd group which treated both the retrograde cavity and cutting surface showed significantly less microleakage than the other groups(p<0.05). There was no significant difference between groups treated on one side only. 3. As a result of SEM observation of dentin surface, obstruction of dentinal tubules with marble shaped granules, which were different from normal dentin could be seen. Cracks could be seen also. 4. In summary of this experiment, it is thought that effort to obstruct the exposed dentinal tubules as well as retrograde cavity after root end resection is needed.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.244-249
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• 1984

Surgical treatment of partial endocardial cushion defect was accomplished in Feb. 1984 in this department. The 5 year old male patient had history of frequent upper respiratory tract infection and since his age of 3 years dyspnea on exertion and palpitation were noted but there were no cyanosis and clubbing. A thrill was palpable on the apex and grade IV/IV harsh systolic ejection murmur and diastolic murmur was audible on it. Liver was palpable about 3 finger breadths and no ascites. Chest X-ray revealed increased pulmonary vascularity, moderate cardiomegaly [C-T ratio; 0.69], and enlarged left atrium. EKG showed first degree heart block, RVH, LVH, and LAD. Echocardiogram showed paradoxical ventricular septal movement and abnormal diastolic movement of the anterior leaflet of mitral valve. Right heart catheterization resulted left to right shunt [Qp:Qs:2.1:1 ] and moderate pulmonary hypertension [60/40 mmHg]. Left ventriculogram showed mitral regurgitation [Grade III/IV] and filling of left atrium and right atrium nearly same time. Operative findings were: 1.Primum type atrial septal defect [3x2 cm] 2.Cleft on the anterior leaflet of mitral valve. 3.No interventricular communication and cleft of tricuspid valve leaflet. The mitral cleft was repaired with 4 interrupted sutures. The primum type atrial septal defect was closed with Dacron patch intermittently at endocardial cushion and continuously remainder. The post operative course was uneventful and discharged on 22nd postoperative day in good general conditions.

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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• pp.52-54
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• 2012

A 10-year-old female patient presented with a rapidly growing nodular mass lesion on her right frontal area. On skull radiography and computed tomography (CT) imaging, this mass had a well-demarcated punch-out lesion with a transdiploic, exophytic soft tissue mass nodule on the frontal scalp. Magnetic resonance (MR) imaging revealed the presence of a $1.5{\times}1.2{\times}1$ cm sized calvarial lesion. This lesion was hypointense on T1 and heterogenous hyperintense on T2 weighted MR images, and exhibited heterogeneous enhancement of the soft tissue filling the punch-out lesion after intravenous administration of gadolinium. En block removal of the tumor with resection of the rim of the normal bone was performed. The pathological diagnosis was intravascular papillary endothelial hyperplasia (IPEH). After surgery, no recurrence was found for 8 months. IPEH is a rare and benign reactive lesion usually found in thrombosed subcutaneous blood vessels. Involvement of skull bone is rare. In this article, we present a case of IPEH involving the calvarium, in a 10-year-old woman.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.165-174
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• 2010

TTG-blocks are concrete blocks designed to be paved around the bridge piers in order to protect the channel bed from local scour. In this study roughness coefficient of T.T.G- blocks are investigated through the hydraulic model test. And critical safety weight of TTG-blocks is derived in terms of Reynolds number for each individual block and group of linked blocks. Flume experiments show that a performance of TTG-blocks is effective to protect the river channel bed from local scour at bridge piers if it is assessed using with geotextile mat under blocks or designated gravels for filling in holes of blocks.

• Journal of Communications and Networks
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• v.18 no.6
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• pp.902-912
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• 2016

Recent advances in energy harvesting (EH) technology have motivated the adoption of rechargeable mobile devices for communications. In this paper, we consider a point-to-point (P2P) wireless communication system in which an EH transmitter with a non-ideal rechargeable battery is required to send a given fixed number of bits to the receiver before they expire according to a preset delay constraint. Due to the possible energy loss in the storage process, the harvest-use-and-store (HUS) architecture is adopted. We characterize the properties of the optimal solutions, for additive white Gaussian channels (AWGNs) and then block-fading channels, that maximize the energy efficiency (i.e., battery residual) subject to a given rate requirement. Interestingly, it is shown that the optimal solution has a water-filling interpretation with double thresholds and that both thresholds are monotonic. Based on this, we investigate the optimal double-threshold based allocation policy and devise an algorithm to achieve the solution. Numerical results are provided to validate the theoretical analysis and to compare the optimal solutions with existing schemes.

• Journal of Technologic Dentistry
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• v.38 no.3
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• pp.165-173
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• 2016

Purpose: This study was conducted to examine the color stability of temporary prosthetic materials for dental CAD-CAM. Method: 2 kinds of existing acrylic resin temporary filling materials and 2 kinds of polymer prosthetic materials for dental CAD-CAM were used for testing, and five specimens respectively were absorbed in soy sauce, red pepper paste, and coffee. A Chroma Meter was used as analysis equipment. The color change of the specimens was observed to calculate ${\Delta}E$ value throughout 2 days, 3 days, 4 days, and 5 days and this was analyzed and the following result was obtained. Results: Snap's ${\Delta}E$ value was bigger than Vipi block(p<0.05). Red pepper paste had the largest impact on the color change of resin(${\Delta}E$), followed by soy sauce and coffee(p<0.000). With the passage of time, ${\Delta}E$ value was inversely(-) related and decreased somewhat(p<0.000).