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Thermal performance evaluation of Temperable Low-e glass window through Heating Energy consumption Analysis (난방에너지 사용량 분석을 통한 후강화 로이유리 창호의 단열성능 평가)

  • Jang, Cheol-Yong;Kim, Jeong-Gook;Ahn, Byung-Lip;Kim, Jun-Sup;Haan, Chan-Hoon
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.200-205
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    • 2012
  • In the high oil price age, intensification of energy efficiency promotion in the building sector is required. Windows are dominating in large percent of whole building loads, and are regarding as the primary target of energy efficiency. In this study, in order to reduce heat loss of buildings, we investigate the thermal performance properties of Temperable Low-e glazing coated Ag membrane that has high electrical conductivity. The Temperable Low-e glazing windows has high insulation and shading properties, and it has strength that can supply various product which consumers want. In order to evaluate thermal performance of temperable windows, we install single low-e windows and double low-e windows in the experimental chamber and analysis the comparison heating energy consumption between single and double Low-e glazing windows. performance evaluation was conducted.

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Development and Evaluation of a Novel Electro-mechanical Implantable Ventricular Assist System (전기-기계식 이식형 좌심실 보조 시스템의 개발 및 평가)

  • 조한상;김원곤;이원용;곽승민;김삼성;김재기;김준택;류문호;류은숙
    • Journal of Biomedical Engineering Research
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    • v.22 no.4
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    • pp.349-358
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    • 2001
  • A novel electro-mechanical implantable ventricular assist system is developed as a bridge to transplantation or recovery for patients with end-stage heart failure. The developed system is composed of an implanted blood pump, an external monitoring system which stores data, and a wearable system including a portable external driver and a portable power supply system. The blood pump is designed to be implanted into the left upper abdominal space and provides blood flow from the left ventricular apex to the aorta. The pulsatile blood flow is generated by a double cylindrical cam. There was mo excessive heat emission from the blood pump into the temperature-controlled chamber in the heat test and no stagnated flow within the blood sac by the observation in the flow visualization test. Animal experiments were performed using sheep and calves. The maximum assist flow rate reached 7.85L/min in the animal experiment. The evaluation results showed that the developed system was feasible for the implantable ventricular assist system. The long-term in vitro durability test and mid-term in vivo experiments are in progress and mow the modified next model is under development.

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Fabrication of YBCO superconducting film with CeO2/BaTiO3double buffer layer (CeO2/BaTiO3 이중완충막을 이용한 YBCO 박막 제작)

  • 김성민;이상렬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.790-793
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    • 2000
  • We have fabricated good quality superconducting YBa2Cu3O7x(YBCO) thin films on Hastelloy(Ni-Cr-Mo alloys) metallic substrates with CeO2and BaTiO3buffer layers in-situ by pulsed laser deposition in a multi-target processing chamber. YBCO film with CeO2 single buffer layer shows Tc of 71.64 K and the grain size less than 0.1 {\mu}{\textrm}{m}. When BaTiO3is used as a single buffer layer, the grain size of YBCO is observed to be larger than that of YBCO/CeO2by 200 times and the transition temperature of the film is enhanced to be about 84 K. CeO2/BaTiO3double buffer layer has been adopted to enhance the superconducting properties, which results in the enhancement of the critical temperature and the critical current density to be about 85 K and 8.4 × 104 A/cm2 at 77 K, respectively mainly due to the enlargement of the grain size of YBCO film.ilm.

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Fabrication of YBCO Superconducting Film with CeO2/BaTiO3Double Buffer Layer (CeO2/BaTiO3이중완충막을 이용한 YBCO 박막 제작)

  • 김성민;이상렬
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.11
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    • pp.959-962
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    • 2000
  • We have fabricated good quality superconducting YBa2Cu3O7x(YBCO) thin films on Hastelloy(Ni-Cr-Mo alloys) metallic substrates with CeO2and BaTiO3buffer layers in-situ by pulsed laser deposition in a multi-target processing chamber. YBCO film with CeO2single buffer layer shows Tc of 71.64 K and the grain size less than 0.1{\mu}{\textrm}{m}. When BaTiO3 is used as a single buffer layer, the grain size of YBCO is observed to be larger than that of YBCO/CeO2by 200 times and the transition temperature of the film is enhanced to be about 84 K. CeO2/BaTiO3double buffer layer has been adopted to enhance the superconducting properties, which results in the enhancement of the critical temperature and the critical current density to be about 85 K and 8.4×104 A/cm2 at 77 K, respectively mainly due to the enlargement of the grain size of YBCO film.ilm.

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Characterization on the Thermal Oxidation of Raw Natural Rubber Thin Film using Image and FT-IR Analysis

  • Kim, Ik-Sik;Cho, Hwanjeong;Sohn, Kyung-Suk;Choi, Hwa-Soon;Kim, Sung-Uk;Kim, Sinkon
    • Elastomers and Composites
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    • v.55 no.1
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    • pp.51-58
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    • 2020
  • In this study, the thermal oxidation of raw natural rubber (NR) was investigated under controlled conditions by optical image and fourier transform infrared (FT-IR) analysis. The thermal oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at 80℃ under low humidity conditions to completely exclude moisture and restrict light oxidation. Images of the thin film of raw NR were obtained before and after thermal oxidation. FT-IR absorption spectra were measured in the transmission mode at different thermal exposure times. The thermal oxidation of NR was examined by the changes in the absorption peaks at 3449, 1736, 1447, 1377, 1242, 1072, and 833 cm-1, which corresponded to a hydroxyl group (-OH), a carbonyl group (-C=O) from an aldehyde and a ketone, a methylene group (-CH2-), a methyl group (-CH3), a carbon-oxygen single bond (-C-O) from an epoxide, a carbon-oxygen bond (-C-O) from an ether, an alcohol, a peroxide, or a cyclic peroxide, and a cis-methine group (cis-CCH3=CH-), respectively. In the initial stage of thermal oxidation, two different types of free radicals were produced quickly and randomly by the homolytic cleavage of a double bond and allylic hydrogen abstraction. Aldehydes and ketones were formed from chain scissions of the double bonds and alcohols were produced from allylic hydrogen abstraction at the methylene or methyl groups. Two reactions seemed to proceed competitively with each other. At a later stage, oxidative crosslinks seemed to dominate through the combination of free radicals such as an allyl radical (CH=CHCH2·), alkoxy radical (RO·), and peroxy radical (ROO·) and the reaction of a hydroperoxide (-ROOH) with a double bond. The image obtained after thermal oxidation showed hardening without cracks. Based on these observations, a plausible two-step mechanism was suggested for chain hardening caused by the thermal oxidation.

Development of cryogenic liquid-vapor separator and liquid-level meter operating under high pressure condition (고압 상황에서 작동되는 극저온 기액 분리기와 액체 계면 측정기의 개발)

  • Lee, Cheon-Kyu;Hwang, Gyu-Wan;Jeong, Sang-Kwon
    • Progress in Superconductivity and Cryogenics
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    • v.13 no.1
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    • pp.51-55
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    • 2011
  • In this study, the liquid-vapor (L-V) separator equipped with liquid-level meter is developed. In the developed L-V separator, the flange is designed to be attachable so that the separator can be flexibly applied under any cases where the volumetric of L-V separator is varied by the system requirement. The leak-tightness between the attachable flange and the chamber is experimentally confirmed with the use of double groove indium wire sealing even under the high pressure up to 20 bar. In addition, the liquid-level meter is designed and fabricated to figure out the inner state of L-V separator. It consists with 19 carbon composition resistors in series. All resistors are separately calibrated in the temperature range from 77 K to 200 K. The performance of the L-V separator and the liquid-level meter is investigated with experimental tests, and the result is presented in this paper.

Fistula Between Right Coronary Artery and Right Ventricle: Report Of 3 Cases (관상동정맥루 치험 3예)

  • 곽상룡
    • Journal of Chest Surgery
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    • v.15 no.1
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    • pp.112-117
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    • 1982
  • Communications of coronary arteries with the cardiac cavities have first time been described by Krause in 1865 in a case of an accessory artery draining into the pulmonary artery and later Cayla in a case of a right coronary artery entering the right ventricle. The initial cases have been found accidentally at autopsies, however In recent years after the Introduction of angiography and coronary arteriography, the malformation Is diagnosed during life and is corrected surgically. These conditions are unusual entitles since the advent of angiography they are being diagnosed with increasing frequency. Three patients who had surgical correction of coronary-cardiac chamber fistula at our hospital are presented. In the first case and second case, coronary arteriovenous fistula was corrected horizontal mattress suture ligation with pladget under the cardiopulmonary bypass and third case was corrected double ligation with cardiopulmonary bypass standby. The postoperative courses were uneventful. They discharged without any fistula related complica-tions.

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Analysis of Cushion Mechanism with Relief Valve for High-Speed Pneumatic Cylinders (고속 공기압 실린더용 릴리프밸브형 쿠션기구의 특성 해석)

  • Kim, Do-Tae;Zhang, Zhong Jie
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.3
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    • pp.95-103
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    • 2010
  • This paper presents a simulation model of a double-acting high-speed pneumatic cylinder with a relief valve type cushion mechanism. The model predicts piston motion, mass flow rate, pressure and temperature time histories of cushion chamber. Of interest here is to investigate the cushioning effect of varying the piston and piston-rod diameter, cushion ring diameter and length, and stoke in cushion mechanism. As a result, this cushion mechanism is found to be adequate under high-speed driving of pneumatic cylinders. The simulation model proposed here will be very useful to analyze the dynamic characteristics and to improve or design the better cushion mechanism in high-speed pneumatic cushion cylinders.

The study on the SiO2 film non-uniformity by Plasma Enhanced Chemical Vapor Deposition (PECVD로 증착된 SiO2의 non-uniformity 특성 연구)

  • Ham, Yong-Hyun;Kwon, Kwang-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.73-73
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    • 2008
  • In this work, the study on the SiO2 film non-uniformity by PECVD (Plasma Enhanced Chemical Vapor Deposition) was performed. Plasma diagnostics was analyzed by a DLP(Double Langmuir Probe) and a probe-type QMS(Quadrupole Mass Spectrometer) in order to investigate the spatial distribution of the plasma species in the chamber. The relationship between the plasma species and the depositing rate of the films was examined. On the basis of this work, it was confirmed that O radical density mainly contributed to the increase in the depositing rate of the SiO2 films and the electron temperature in the plasma had a main effect on the formation of the oxygen radicals.

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Development of a Simplified Test Apparatus for Measuring Sound Transmission Loss (간이 차음시험장치 개발)

  • 이해성;전오성;강현주;김봉기
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.892-897
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    • 2003
  • This study deals with the performance of a simplified test apparatus for measurement of sound insulation of panels. In order to investigate its performance, results from experiment and theory of the sound transmission loss for single and double panels are compared. Comparative results show that in evaluation of the sound insulation performance, the test apparatus has a cumbersome problem at the low frequency region, i.e. below 315 ㎐, presumably because of the poor diffuse sound field in the chambers. Meanwhile at the high frequency, it shows a considerable results comparable to the theoretical prediction. One of the objective of this study that compares measured results between a real reverberation chamber and a simplified test apparatus, by using a specimen of a sandwich panel. It shows qualitatively resonable agreement from which one can find a potential to provide a design tool.

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