• Title/Summary/Keyword: Double chamber

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The Structual Restoration on Gyeongju-Style Piled Stone-Type Wooden Chamber Tombs (경주식 적석목곽묘의 구조복원 재고)

  • Gweon, Yong Dae
    • Korean Journal of Heritage: History & Science
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    • v.42 no.3
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    • pp.66-87
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    • 2009
  • The definition of the structure of wooden chamber tomb(piled stone-type) is as follows. It is a tomb with wooden chamber, and stones were piled on top of the wooden chamber, and then a wooden structure was placed on top of the piled stones, and more stones were piled on top of the wooden structure, and sealed with clay. Of course this definition can vary according to periods, the buried, etc. Gyeongju-style piled stone type wooden chamber tombs have some distinguished characteristics compared to general definition of piled stone type wooden chamber tombs. Outside the wooden chamber, either stone embankments or filled-in stones were layed out, and pilet-in stones are positioned right above the wooden chamber, and almost every class used this type, and finally, it is exclusively found in Gyeongju area. First generations of this Gyeongju-style piled stone type wooden chamber tombs appeared in first half of 5th century. These tombs inherited characteristics like ground plan, wooden chamber, double chamber(inner chamber and outer chamber), piled stones, burial of the living with the dead, piled stones, from precedent wooden chamber tombs. However these tombs have explicit new characteristics which are not found in the precedent wooden chamber tombs such as stone embankments, wooden pillars, piled stones(above ground level), soil tumuluses. stone embankments and wooden pillars are exclusively found on great piled stone type above-ground level wooden chamber tombs such as the Hwangnamdaechong(皇南大塚). Stone embankments, wooden pillars, piled stones(above ground level) are all elements of building process of soil tumuluses. stone embankments support outer wall of above-ground level wooden chambers and disperse the weight of tumuluses. Wooden pillars functioned as auxiliary supports with wooden structures to prevent the collapse of stone embankments. Piled stones are consists of stones of regular size, placed on the wooden structure. And after the piled stones were sealed with clay, tumulus was built with soil. Piled stones are unique characteristics which reflects the environment of Gyeongju area. Piled stone type wooden chamber tombs are located on the vast and plain river basin of Hyeongsan river(兄山江). Which makes vast source of sands and pebbles. Therefore, tumulus of these tombs contains large amount of sands and are prone to collapse if soil tumulus was built directly on the wooden structure. Consequently, to maintain external shape of the tumulus and to prevent collapse of inner structure, piled stones and clay-sealing was made. In this way, they can prevent total collapse of the tombs even if the tumulus was washed away. The soil tumulus is a characteristic which emerges when a nation or political entity reaches certain growing stage. It can be said that after birth of a nation, growing stage follows and social structure will change, and a newly emerged ruling class starts building new tombs, instead of precedent wooden chamber tombs. In this process, soil tumulus was built and the size and structure of the tombs differ according to the ruling class. Ground plan, stone embankments, number of the persons buried alive with the dead, quantity and quality of artifacts reflect social status of the ruling class. In conclusion, Gyeongju-style piled stone type wooden chamber tombs emerged with different characteristics from the precedent wooden chamber tombs when Shilla reached growing stage.

A STUDY ON THE SEALING PROPERTIES OF TEMPORARY FILLING MATERIALS USED IN ENDODONTICS (근관치료시 사용되는 수종 임시충전재의 변연 폐쇄효과에 관한 연구)

  • Yoo, Hyun-Mee;Kwon, Hyuk-Choon
    • Restorative Dentistry and Endodontics
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    • v.16 no.2
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    • pp.33-42
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    • 1991
  • The purpose of this study was to evaluate the sealing properties of the temporary filling materials used in endodontic treatment Access cavities were prepared in 135 extracted human molar teeth. Then, cotton pellets were placed in the pulp chamber until the depth of 5 mm for the temporary filling materials; Caviton, zine oxide-eugenol, double sealing (A) (stopping 15 mm + zinc oxide - eugenol, 3.5mm ) double sealing (B) (stopping 3.0 mm + zinc oxide - eugenol 2.0 mm) and gutta percha stopping. After filling the materials, the teeth were immersed in 1 % methylene blue solutions for 3 days, 1 week and 2 weeks. Then thermal cycling was performed at the temperature of $60^{\circ}C$ and $4^{\circ}C$, followed by longitudinal sections on the center of tooth. Finally, staining on the cotton pellet was evaluated. The following results were obtained. 1. Stopping showed lower marginal sealing quality than Caviton, zinc oxide - eugenol and double sealing. 2. In 1 week group, Caviton showed higher marginal sealing quality than zinc oxide-eugenol, double sealing and stopping. 3. Caviton and double sealing (B) showed a great decrease in marginal sealing quality with the increse of time. 4. Caviton had high marginal sealing quality in 3 day group and 1 week group, but in 2 week group, Caviton showed a great decrease. 5. Double sealing (B) showed fairly high marginal sealing quality in 3 day group, but decreased greatly after 1 week on.

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A Study on Performance of Double-Core PBD for Improving Thick Reclaimed Ground (대심도 연약지반 개량을 위한 이중코어 PBD 성능연구)

  • Yang, Jeong-Hun;Hong, Sung-Jin;Lee, Woo-Jin;Choi, Hang-Seok;Kim, Hyung-Sub
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.281-292
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    • 2008
  • Prefabricated Board Drains (PBDs) recently become more widely used than conventional sand drains in improving soft ground because the PBD is more time and cost effective. The performance of PBDs is affected by disturbance in the adjacent soil formation during inserting mandrels, the intrusion of fine particles into filter fabric, and necking of the drain by excessive lateral pressure especially occurring in very deep clay formation such as the Busan New Port site. In this study, the PBD with double-core is introduced, which seems to overcome the shortcomings of usual single-core PBDs. An in-situ test program was established in the Busan New Port site, in which a set of the double-core PBDs and the single-core PBDs was installed to compare the efficiency of each of the drains. The discharge capacity of the double-core and the single-core PBDs was compared for various confining pressures in the modified Delft test and the chamber test. A series of CRS consolidation tests was performed in order to obtain profiles of void ratio-effective stress and void ratio-permeability relationships in the Busan New Port site that are used as input date in performing a numerical program ILLICON. The numerically simulated settlements of ground surface in the test site are in good agreement with those of in-situ measurements. In addition, the performance of the double-core and single-core PBDs has been experimentally and numerically compared in this paper.

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Measurement of Thermal Deformation of a Double Ring Structure using Digital Image Correlation Technique (디지털 영상 보정 기법을 이용한 이중 링 구조물의 열변형 측정)

  • Jin, Tailie;Goo, Nam-Seo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.9
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    • pp.877-882
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    • 2011
  • In this paper, thermal deformation of a double ring structure using digital image correlation technique (DIC) was measured. The double ring structure consisted of two parts; the inner ring was aluminium which had a large thermal expansion coefficient and the outer ring was titanium which had a small thermal expansion coefficient. We heated the double ring structure from $50^{\circ}C$ to $200^{\circ}C$ in a chamber and at the same time, two cameras captured surface images of the double ring structure. Initially, there was a 21 ${\mu}m$ gap between the inner ring and outer ring. The gap was closed at around $80^{\circ}C$ and after that, two rings expanded together. In order to compare the experimental results with analysis results, a finite element analysis was performed using ANSYS. The results of DIC measurement and ANSYS analysis were compared and agreed well.

Analysis of a Double Pipe Heat Exchanger for Waste Solvent Recovery (폐용제 회수용 이중관형 열교환기 특성 해석)

  • 구재현;이재근
    • Resources Recycling
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    • v.9 no.3
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    • pp.13-21
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    • 2000
  • This study describes to analyze the heat transfer characteristics of waste solvent recovery system using a double pipe heat exchanger heating solvent by the hot oil. The solvent recovery system consists of the feeding pump, the double pipe heat exchanger, the vacuum spray chamber, and the condenser. A double pipe heat exchanger consists of the first section to conduct the heating of solvent to the thermal saturated point and the second section to evaporate the saturated solvent. The heat transfer area for vaporization of water, benzene and alkylbenzene was predicted by the heat balance modelling and experimentally measured from the temperature distribution as a function of solvent flow rate and heating temperature. The required heat transfer area for vaporization was increased with increasing solvent flow rates and with decreasing heating temperatures due to decreased quantity of transferred heat per the unit area. Theoretical modelling of the heat transfer area for solvents vaporization in the pipe showed good agreement with experimental results. Results showed to be suitable for the waste solvent recovery using a double pipe heat exchanger.

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A Study on Flame and Dynamic Characteristics of Injectors in Liquid Rocket Engine (액체로켓엔진 분사기의 화염 및 동적 특성 연구)

  • Song, Ju-Young;Lee, Kwang-Jin;Seo, Seong-Hyeon;Han, Yeoung-Min;Seol, Woo-Seok
    • 한국연소학회:학술대회논문집
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    • 2004.11a
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    • pp.141-145
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    • 2004
  • The objective of the present study is to conduct model combustion tests for various injectors to identify their combustion stability characteristics. Three different double swirl coaxial injectors with variation of a recess length have been tested for the comparative study of CH flame structure and dynamic characteristics. Gaseous oxygen and mixture of gaseous methane and propane have been employed for simulating actual propellants used for a full-scale thrust chamber. Upon test results, the direct comparison between various types of injectors can be realized for the selection of the best design among prospective injectors.

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A Study on the double-layered dielectric films of tantalum oxide and silicon nitride formed by in situ process (연속 공정으로 형성된 탄탈륨 산화막 및 실리콘 질화막의 이중유전막에 관한 연구)

  • 송용진;박주욱;주승기
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.1
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    • pp.44-50
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    • 1993
  • In an attempt to improve the electrical characteristics of tantalum pentoxide dielectric film, silicon substrate was reacted with a nitrogen plasma to form a silicon nitride of 50.angs. and then tantalum pentoxide thin films were formed by reactive sputtering in the same chamber. Breakdown field and leakage current density were measured to be 2.9 MV/cm and 9${\times}10^{8}\;A/cm^{2}$ respectively in these films whose thickness was about 180.angs.. With annealing at rectangular waveguides with a slant grid are investigated here. In particular, 900.deg. C in oxygen ambient for 100 minutes, breakdown field and leakage current density were improved to be 4.8 MV/cm and 1.61.6${\times}10^{8}\;A/cm^{2}$ respectively. It turned out that the electrical characteristics could also be improved by oxygen plasma post-treatment and the conduction mechanism at high electric field proved to be Schottky emission in these double-layered films.

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Double-chambered right ventricle -One case report- (이강우심실 -1예 보고-)

  • Jo, In-Taek;Kim, Sang-Hyeong;Lee, Dong-Jun
    • Journal of Chest Surgery
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    • v.19 no.3
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    • pp.515-521
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    • 1986
  • Double-chambered right ventricle [DCRV] is a rare congenital heart disease caused by anomalous muscle bundle traversing the sinus portion of the right ventricle well beneath the infundibulum. Recently we have experienced a case of DCRV with ventricular septal defect in 7-year old male patient. Preoperative cardiac catheterization and cineangiography revealed 80 mmHg pressure gradient between the proximal and distal chamber of the right ventricle and diagonal shape filling defect by the anomalous muscle bundle in the sinus portion of the right ventricle. Resection of the anomalous muscle bundle and patch closure of the ventricular septal defect was performed with cardiopulmonary bypass. The postoperative course was uneventful and excellent.

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A Study on the Combustion Stability Evaluation of Double Swirl Coaxial Injector (이중 와류 동축형 분사기의 연소안정성 평가에 관한 연구)

  • ;;;Kim, Hong-Jip;Choe, Hwan-Seok;Lee, Su-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.12
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    • pp.41-47
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    • 2006
  • A liquid rocket thrust chamber should have a high confidence in its combustion performance and combustion stability. Expecially, the injector of which function is spraying and mixing propellants plays an important role in getting the confidence. This study was carried out to evaluate combustion stability of a double swirl coaxial injector by using the model similarity method. Besides, in case of a baffle which was used to improve combustion stability, the length and gap effects of the baffle were investigated.

Double-Outlet of Left Ventricle in Corrected Transposition of Great Arteries -One case report- (좌심실 이중유출로를 동반한 교정형 대혈관전위증 -1예보고-)

  • 권중혁
    • Journal of Chest Surgery
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    • v.12 no.2
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    • pp.119-126
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    • 1979
  • This is one case report of the extremely rare congenital cardiac malformation, Double-outlet of left ventricle in corrected transposition of great arteries. 11-year-old boy complained acrocyanosis and exertional dyspnea, the parents noticed cyanosis since birth. Physical examination revealed acrocyanosis, clubbed fingers and toes, G-III pansystolic murmur on 2nd and 3rd ICS, LSB. Right heart catheterization revealed significant $O_2$ jump in ventricular level. Right and left ventriculography showed the both catheters arriving in the same ventricle i.e. anterior chamber, morphological left ventricle was in right and anterior position, simultaneous visualization of aorta and pulmonary artery and aorta locating anterior and right side of pulmonary artery. Echo cardiogram surely disclosed interventricular septum. Conclusively it was clarified that the patient has Double-outlet of left ventricle and corrected transposition of great arteries [S.L.D.]. Operation was performed to correct the anomalies under extracorporeal circulation with intermittent moderate hypothermia. Right-sided ventriculotomy disclosed the following findings. 1. Right-sided ventricle was morphological left ventricle. 2. Left-sided ventricle was morphological right ventricle. 3. Right side atrioventricular valve was bicuspid. 4. Left side atrioventricular valve was tricuspid. 5. Aortic valve was superior, anterior and right side of pulmonary valve. 6. Subpulmonary membranous stenosis. 7. Non-committed ventricular septal defect. We made a tunnel between VSD and aorta with Teflon patch so that arterial blood comes through VSD and the tunnel into aorta. After correction the patient needed assisted circulation for 135 min. to have adequate blood pressure. Postoperatively by any means, adequate blood pressure could not be maintained and expired in the evening of operation day.

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