• Title/Summary/Keyword: Pressure-tightness

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The Effect and Side Effect of Dipyridamole in Myocardial SPECT (Dipyridamole 부하 심근 SPECT에서 Dipyridamole의 작용과 부작용)

  • Yang, Hyung-In;Lee, Dong-Soo;Yeo, Jeong-Suk;Bae, Sang-Kyun;Choi, Chang-Woon;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.27 no.2
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    • pp.203-209
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    • 1993
  • Dipyridamole is an agent that may be used to noninvasively evaluate coronary artery disease. The effect of dipyridamole infusion its generally related to its induced peripheral vasodilatory effect. In normal person, heart rate is generally increased slightly while blood pressure decrease, but the achieved double product and related myocardial oxygen consumption have no significant change. The purpose of this study is to examine the effect and side effect of dipyridamle, and to compare different response to dipyridamole among the patients. We evaluated 847 patients who underwent dipyridamole stress myocardial SPECT. 93.6% of them had induced hypotension, 0.9% showed no change of blood pressure, 5.5% had increased blood pressure. 8.3% had no change of pulse rate more than 10% of basal pulse rate. Among diabetes, 16.9% was not change of pulse rate, 6.7% in non-diabetes. There was no significant correlation between age and rate pressure product rest(RPPr), in patiens without perfusion defects on SPECT(y=7.1x+ 48.4 r=0.13 p>0.01). As increasing age, RPPs/RPPr was declined(y= -11.6x+68.9 r=0.17 p<0.01), similar results were obtained in patients with perfusion defect. The size of perfusion defect on myocardial SPECT have no correlation between RPPr and RPPs/RPPr. The side effects of dipyridamole included chest pain and chest tightness, headache, abdominal pain, dizzness, nausea, and dyspnea. As increasing age, dipyridamole-induced cardiac work at rest was increased, cardiac response to dipyridamole was decreased.

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Assembly and Test of the In-cryostat Helium Line for KSTAR (KSTAR 저온용기 내부의 헬륨라인 설치 및 검사)

  • Bang, E.N.;Park, H.T.;Lee, Y.J.;Park, Y.M.;Choi, C.H.;Bak, J.S.
    • Journal of the Korean Vacuum Society
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    • v.16 no.2
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    • pp.153-159
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    • 2007
  • In-cryostat helium lines are under installation to transfer a cryogenic helium into cold components in KSTAR device. In KSTAR, three kinds of helium should be supplied into the cold components, which are supercritical helium Into superconduction(SC) magnet system, liquid helium into current lead system, and gas helium into thermal shields. Cryogenic helium lines consist of transfer lines outside the cryostat, in-cryostat helium lines, and electrical breaks. In-cryostat helium lines should be guaranteed of leak tightness for tong time operation at high internal helium pressure of 20 bar. We wrapped the helium line with multi-layer insulator(MLI) to reduce radiation heat and insulated the surface of the high potential part with prepreg tape. The electrical break was fabricated by brazing ceramic tube with stainless steel tube. To ensure the operation reliability at operation temperature, all the electrical break have been examined by the thermal cycle test at liquid nitrogen and by the hydraulic test at 30 bar. And additional surface insulation was prepared with prepreg tape to give structural safety. At present most of the in-cryostat helium lines have been installed and the final inspection test is progressing.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016 (설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.6
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    • pp.327-340
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    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.