• Journal of Korean Society for Atmospheric Environment
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• v.30 no.5
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• pp.461-476
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• 2014

Continuous Water-Soluble Organic Carbons (WSOC) by the Particle Into Liquid Sampler - Total Organic Carbon (PILS-TOC) analyzer were measured at the Seoul intensive monitoring site from June 17 through July 5 in 2014. In addition, the 24 hour integrated PM2.5 collected by Teflon and Quartz filters were analyzed for water soluble ions by Ion chromatography (IC), WSOC by TOC from water extracts, organic carbon (OC), elemental carbon (EC) by carbon analyzer using the thermal optical transmittance (TOT) method, and mass fragment ions (m/z) related to alkanes and PAHs (Poly Aromatic Hydrocarbons) by Gas Chromatography-Mass Spectrometer-Thermal Desorption (GC/MS-TD). Based on the statistical analysis, four different Carbonaceous Thermal Distributions (CTDs) from OCEC thermal-gram were identified. This study discusses the primary and secondary sources of WSOC based on the Classified CTD, organic mass fragments, and diurnal patterns of WSOC. The results provide knowledge regarding the origins of WSOC and their behaviors.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.183-191
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• 1993

The homogeneous dose planning is one of the most important roles in radiation therapy. But, it is not easy to obtain a homogeneous dose to paranasal sinus region including the ethmoidal sinus with conventional irradiation techniques. In this experimental study, the authors tried to get a homogeneous dose at PNS region, but the nasal cartirage does not exceed the tolerance dose, with anterior-posterior beam and two both lateral wedged beams. Used three fields were shielded with full thickness of blocks to preserve the eye-balls and with blocks of one half value layer to create a homogeneous dose at the whole treatment volume. The dose computations are based on the three dimensonal structure with modified scatter contributions of partial shielders and attenuated beams in 6 MV photon beams. The dose distributions of mid-plane is examined with Kodak verification films and teflon-embedded TLD rod (1 mm diameter and 6 mm length) to confirm the computed dose. In our study, the whole PNS regions have shown within $85{\%}$ of the resultant isodose curves with relatively homogeneous dose distribution. The results of dose computation and measurements are agree well within $5{\%}$ uncertainties.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.11 s.242
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• pp.1182-1188
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• 2005

An x-ray PIV (Particle Image Velocimetry) technique was developed to measure quantitative information on flows inside opaque conduits and on opaque-fluid flows. At first, the developed x-ray PIV technique was applied to flow in an opaque Teflon tube. To acquire x-ray images suitable for PIV velocity field measurements, refraction-based edge enhancement mechanism was employed using detectable tracer particles. The optimal distance between with the sample and detector was experimentally determined. The resulting amassed velocity field data were in reasonable agreement with the theoretical prediction. The x-ray PIV technique was also applied to blood flow in a microchannel. The flow pattern of blood was visualifed by enhancing the diffraction/interference -bas ed characteristic s of blood cells on synchrotron x-rays without any contrast agent or tracer particles. That is, the flow-pattern image of blood was achieved by optimizing the sample (blood) to detector distance and the sample thickness. Quantitative velocity field information was obtained by applying PIV algorithm to the enhanced x-ray flow images. The measured velocity field data show a typical flow structure of flow in a macro-scale channel.

• Journal of Chest Surgery
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• v.14 no.3
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• pp.254-259
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• 1981

This is a case of successfully surgically treated RVOT obstruction caused by projection of the herniated aortic cusp through subpulmonic supracristal VSD at Department of Thoracic and Cardiovascular Sugery, Hanyang University Hospital. The patient was a 17 year old boy. Congenital heart anomaly was suspected at 2 years of his age. He had palpitation, dyspnea on exertion and epistaxis for 2 years prior to admission to our hospital. On examination, the blood pressure was 170/0mmHg. And the pulse rate was 100/rain. Widening of pulse pressure, water hammer pulse [bounding pulse]. To and fro murmur and head nodding were noted. Cardiomegaly was seen in chest x-ray. EKG, Echocardiography, Cardiac catheterization and angiocardiography were performed. On April 27, 81. Open heart surgery was performed under the impression of VSD combined with AI. On Rt. ventriculotomy, we noticed RVOT obstruction caused by prolapsed rt coronary cusp through a VSD. The subpulmonic supracristal VSD measuring 2.5 x 3 Cm in diameter was closed with Teflon patch graft and then the prolapsed aortic leaflet was plicated by placing three 8-figure suture between the free edge and the base of the leaflet through transverse aortotomy. After operation, excellent result was obtained: B.P, was 110/50mmHg and any sign of AI or residual shunt was not found at discharge.

• Journal of Chest Surgery
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• v.16 no.2
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• pp.175-183
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• 1983

Ventricular aneurysm which was first described by John Hunter on 18th century, has been experienced by many surgeons after successful using of cardiopulmonary bypass by Cooley on 1958. According to Gorlin, the definition of ventricular aneyrysm is portion of the ventricle which is not motile at systole (akinesis) or which has paradoxical dilatation at systole(dyskinesis). The ventricular aneurysm is classified to anatomical and functional. The anatomical ventricular aneurysm is devided into true or false again. Average age incidence is ranged from 49 to 60 and male predominance is reported. The cause is ischemic coronary artery disease in almost cases but hypertropoc cardiomyopathy, congenital abscence of myocardium, complication after mitral valvular replacement and trauma may also cause the ventricular aneurysm. Angina pectoris and congestive heart failure are most common clinical manifestations Ventricular tachycardia and systemic embolization are also complained. Using cardiopulmonary bypass, aneurysmectomy alone or combination with coronary artery revasculization are currently done for surgical treatment with steady improvenment of mortality. The first patient was 33 years old man who had true type of ventricular aneurysm on inferior wall the left ventricle near apex with protruded huge organized thrombus. The thromboembolic phenomenon was noted on both lower extremities. Under cardiopulmonary bypass, aneurysmectomy and thrombectomy were done. The aneurysmal orifice was repaired with Teflon buttless suture. The second patient was 30 years old female who had large true type of ventricular aneurysm on inferior wall of the left ventricle. Under cardiopulmonary bypass, aneurysmectomy with repair of aneurysmmal orifice defect by means of double layered Dacron patch was done with reinforce by outer silastic sheet covering. She was discharged from hospoital at post op. 15th day uneventfully.

• Journal of Chest Surgery
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• v.5 no.1
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• pp.29-34
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• 1972

Interventricular Septal Defect is probably the most common congenital cardiac lesion. Despite rapid technical advances and increasing surgical experience the risk of surgical intervention for correction of Ventricular Septal Defect in infants with pulmonary hypertension remains formidable. Since Sirak et al [1959] reported a succesful case of two stage approach to their surgical correction, it has led to a policy of primary palliation,followed by complete correction as a secondary procedure, after age 3 to 4 years. Most surgeon prefer to perform complete correction of Ventricular Septal Defect when body weight exceeds 30 Lbs. and before development of so-called Eisenmengers complex, for the good postoperative results. Authors report 2 cases of Ventricular Septal Defect with pulmonary hupertenslon, who was underwent pulmonary artery banding as a palliative procedure in the Department of Surgery,Severance Hospital Yonsei University. Case 1:4 year old male, initially a complete correction of Ventricular Septal Defect was attempted by the help of mild hypothermia and extracorporeal circulation. During the procedure of a construction of an extracorporeal by- pass, a sudden cardiac arrest developed. After resuscitation of the heart,pulmonary artery banding was performed as a palliation. On the first postoperative day the patient developed generalized tonic convulsion, cyanosis, vomiting and eventually shock. Patient discharged home after a full recovery. Case 2.: 9 month old female, the pulmonary artery constricted with Teflon patch successfully. After the patients first postoperative day several cyanotic spells developed followed by 3 cardiac arrests. This repeated until when she expired with respiratory failure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.358-362
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• 2006

Pyro-shock generally refers to the severe mechanical transients caused by the detonation of an ordnance device on a structure. Such device on a structure, including linear explosive, and point explosive are widely used to accomplish in-flight separation of structural elements on aerospace vehicle. And they are a significant cause of launch vehicle failures. The launch vehicle being developed in Korea also uses the explosive for separation events. In this paper, the isolator equipped to small satellite launch vehicle made of PTFE(Teflon) is developed to reduce the separation shock. The test to measure dynamic stiffness of PTFE isolator is performed. This test enables us to find the frequency range of PTFE isolator. And,, pyre-shock test using explosive to evaluate the performance of PTFE isolator is executed. from this study, the isolator conformed to frequency range and load requirement is developed using PTFE instead of rubber.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.576-576
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• 2012

High quality single crystalline strain controlled wurtzite ZnO nanowire arrays have been grown on conductive silicon and ITO substrates by a facile hydrothermal method. The diameter of the nanowires was found to be less than 90 nm approximately for both of the two kinds of substrates. The quality of the ZnO nanowire arrays is dramatically improved by hanging the substrate above from the bottom of the Teflon lined autoclave. The structural investigation indicates the preferential orientation of the nanowire along c-axis. In order to make the convincible comparison, the photoluminescence property of the nanowire arrays grown under different conditions are measured, the sharp near band edge emission from PL, low turn-on voltage ($1.9V/{\mu}m$) from field emission measurement and Fowler-Nordheim plot was investigated from ZnO nanowire arrays grown by proposed substrate hanging method.

• Journal of Powder Materials
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• v.19 no.4
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• pp.259-263
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• 2012

Dependence of the freeze-drying process condition on microstructure of porous W and pore formation mechanism were studied. Camphene slurries with $WO_3$ contents of 10 vol% were prepared by milling at $50^{\circ}C$ with a small amount of dispersant. Freezing of a slurry was done in Teflon cylinder attached to a copper bottom plate cooled at $-25^{\circ}C$. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $800^{\circ}C$ for 30 min, and sintered in the furnace at $900^{\circ}C$ for 1 h. After heat treatment in hydrogen atmosphere, $WO_3$ powders were completely converted to metallic W without any reaction phases. The sintered samples showed large pores with the size of about $70{\mu}m$ which were aligned parallel to the camphene growth direction. Also, the internal wall of large pores and near bottom part of specimen had relatively small pores with dendritic structure due to the growth of camphene dendrite depending on the degree of nucleation and powder rearrangement in the slurry.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.675-684
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• 2000

A novel dry and wet deposition collector, which can overcome the several problems such as water evaporation cartridge cracks and high costs founded in the previous collector systems, has been constructed. ENVI-18 SPE adsorption cartridge has been used to measure atmospheric deposition of polycylic aromatic hydrocarbons (PAHs). A surrogate surface, consisted of water and methanol, was filled in the dry deposition funnel to simulate dry deposition onto water surface. A water supply system in order to compensat evaporation of the surrogate surface was used and it was consisted of a piston pump, a tubing pump, a overflow tube and a chamber system. A novel water vaporizing system to supply water onto the wet SPE cartridge system with a constant flow rate was developed. The novel water vaporizing system, consisted of a vacuum pump, a water supply reserviour and tube and a mini space heater, could prevent the PAHs adsorption cartridge cracks occurred in the previous collector and effectively adsorb PAHs. The novel dry and wet deposition collector showed a good adsorption, desorption, and recovery rates of PAHs. By reducing the number of pumps used and employing polypyopylene (PP) instead of teflon as a material of collection funnel, the total construction costs were much reduced as compared with the previous dry and wet deposition collectors.