• Title/Summary/Keyword: Re-circulation

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Anomalous right coronary artery from pulmonary artery discovered incidentally in an asymptomatic young infant

  • Kim, Kyu Seon;Jo, Eun Young;Yu, Jae Hyeon;Kil, Hong Rang
    • Clinical and Experimental Pediatrics
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    • v.59 no.sup1
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    • pp.80-83
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    • 2016
  • Isolated anomalous right coronary artery originating from the pulmonary artery (ARCAPA) is a rare congenital coronary anomaly that is asymptomatic and discovered incidentally in most cases. ARCAPA is generally not considered a fatal defect in infancy or childhood, although cases of sudden death have been reported. Here, we report a 2-month-old female infant who presented with a prolonged fever that was determined to be caused by rhinovirus infection. Myocardial ischemia of the left ventricular posterior wall was already seen on echocardiography, and ARCAPA was discovered incidentally. The patient underwent successful surgical reimplantation of the right coronary artery to the aortic root to re-establish dual ostial circulation.

A Numerical Study on the Vertical Distribution of PM concentration during Asian Dust

  • Cho, Changbum;Kim, Yoo-Keun;Lim, Yunkyu;Lee, Pyeongkeun;Oh, Sung-Nam
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.51-52
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    • 2003
  • A numerical study on PM using a dispersion and deposition model which can analyze for both quantify and quality would not only offer us to understand our environment more easily, but also make it easy that we can make a plan in order to prevent air pollution. The U.S. EPA has proposed the CALPUFF modeling system as a guideline model for regulatory applications involving long-range transport and on a case-by-case basis for near-field applications where. non- steady- state effects which consider situations such as spatial variability in the meteorological fields, calm winds, fumigations, re-circulation or stagnation, and terrain or coastal effects may be important. (omitted)

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A Study on Oil Separation Performance of Crank-Case Ventilation System (크랭크실 환기장치의 오일 분리효율에 관한 연구)

  • Seo, Joon-Ho;Na, Byung-Chul;Kim, Jin-Yong;Park, Seung-Uk;Lim, Dae-Soon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.3
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    • pp.144-150
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    • 2008
  • This research aims to develop parts for advanced fuel/oil filtering re-circulation applicable to this kind of regulation proof engines. These parts can playa role of converting traditional air emission type crankcase into recovery type crankcase so that the engine can deal with environmental regulations, which do not allow minimal amount of toxic gas discharge. For the experiment, test method and specially made testing equipment are prepared. The results showed that oil separation efficiency of the cone type CCV(Crank Case Ventilation) system was higher than one of cylinder type both in bench test and in engine.

A Development Study on High Quality Drinking Water Production by the Biological Activated Carbon/immersed Membrane Filtration System

  • Inoue, Shiro;Iwai, Tosinori;Isse, Masaaki;Terui, Taturo
    • Proceedings of the Membrane Society of Korea Conference
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    • 2001.07a
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    • pp.155-162
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    • 2001
  • Advanced drinking water production systems, which not only good quality product water, but also provide easy management and mainenance of facilities, and operate on a smaller site area, have been expected to be developed for some time. We are going ahead with a program to deveop an advanced drinking water production system, using immersed membrane filtration combined with biological activated carbon, to meet the need described above. The demonstration plant tests been conducted with surface water from the Yodo-river since Dec. 1998 to measure treatment performance, reliability, and controllability of the system. The quality of product water has consistently remained at a very high level for about 2 years under controlled conditions. Results showed that the re-circulation granular biological activated carbon could suppress the increase of membrane pressure difference and promote a reduction of dissolved organic matter. (This work has been conducted along the ACT21 Programs.)

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A Dynamic Analysis of Technological Innovation Using System Dynamics (시스템 다이나믹스를 이용한 기술혁신의 동태성 분석)

  • Choi Kang-Hwa;Kwak Soo-Il;Kim Soo-Wook
    • Korean Management Science Review
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    • v.23 no.1
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    • pp.87-113
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    • 2006
  • This paper describes a comprehensive approach to examine how technological innovation contributes to the renewal of the firm's competences through its dynamic and reciprocal relationship with R&D and product commercialization. Three theories of technology and innovation (R&D and technological knowledge concept, product-process concept, technological interdependence concept) are used to relate technology and innovation to strategic management. Based on those theories, this paper attempts to identify dynamic relationship between product innovation and process innovation by system dynamics, by investigating the aspect of the dynamic changes of the closed feedback circulation structure in which R&D investments drive technological knowledge accumulation, and such knowledge accumulation actualizes product innovation and process innovation, subsequently resulting in the increase of productivity, customer satisfaction, profit generation, and re-investment on R&D from the created profits. This provides the ability to assess the advantages and disadvantages of different technological innovation strategies and commitments, and the opportunity to explore equilibrium point and suggest a generalized technological innovation model under different industry environment parameters and time-strategies.

An Experimental Study on the Variable Sonic Ejector System (가변형 음속 이젝터 시스템에 관한 실험적 연구)

  • Lee, Jun-Hee;Jung, Sung-Jae;Kim, Heuy-Dong;Koo, Byoung-Soo
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2035-2040
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    • 2004
  • A cone cylinder is used to obtain variable operation conditions for the sonic ejector-diffuser system. The cone cylinder is designed to move upstream and downstream to change the ejector throat area ratio, thus obtaining variable mass flow rates. The present study investigates the effects of ejector throat area ratio and operating pressure ratio on the entrainment of secondary stream for the variable sonic ejector system. In experiment, the ejector throat area is varied in the range from ${\psi}=11.88$ to 66.69, and the operating pressure ratio from $p_{0p}/p_a=1.25$ to 9.0. The results show that the variable sonic ejector system is suitable for a required entrainment ratio of secondary stream by altering the ejector throat area ratio and operating pressure ratio.

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Geochemical and Petrographical Studies on the Fergusonite Associated with the Nb-Y Mineralization Related to the Alkaline Granite, Kyemyeongsan Formation, Korea (계명산층내 알칼리 화강암 기원의 Nb-Y 광화작용에 수반되는 퍼구소나이트의 지구화학 및 산출특성 연구)

  • Park, Maeng-Eon;Kim, Gun-Soo;Choi, In-Sik
    • Economic and Environmental Geology
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    • v.30 no.5
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    • pp.395-406
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    • 1997
  • Some RE (Zr, Nb, REE) ore deposits are located in the middle part of the Korean peninsula. Geotectonically, the RE ore deposits situated on the Kyemyeongsan Formation of northern margin of the Okcheon geosynclinal belt and in the transitional zone between Kyeonggi massif and Okcheon belt. The rare metal deposits distributed in Kyemyeongsan Formation which consists of schist and alkaline granite. The alkali granite has suffered extensive post-magmatic metasomatism and hydrothermal processes. The ore contains mainly Ce-La, Ta-Nb, Y, Y-Nb, Ti-Nb-(U), Nd-Th group minerals. Fergusonite, one of Nb-Y rich REE minerals belonging to the A-B oxides, is most common mineral in the rare metal deposits. The fergusonite bearing rocks may be devided into four types by occurrence features and mineral association, that is, zircon type, allanite vein, feldspar type, and fluorite type. Fergusonites show wide variations in optical properties, due to part of differences in their chemical composition (depending on the types), but also the degree of crystalinity of the individual specimens. Fergusonite metamicts enclosed in biotite are generally surrounded by well developed pleochroic haloes. Usually, fergusonite is accompanied with zircon and other REE-bearing minerals. Petrographical and chemical data are presented for fergusonites which collected different types. $Nb_2O_3$ and $Y_2O_3$ contents range from 48.51 to 53.01 wt.% and 29.18 to 42.02 wt.% respectively. Also, $ThO_2$, (1.83~6.93), $UO_2$, (0.17~2.84), ${\sum}RE_2O_3$ (except to Y) (1.11~8.73), and $TiO_2$, (0.19~1.19 wt.%) contents show variational compositions according to fergusonite types. The ${\sum}RE_2O_3$ of fergusonites are positive relation with $Y_2O_3$ and negative relaton with $ThO_2$ and $({\sum}{RE_2O_3}-{Y_2O_3})$. The $Nb_2O_3$ is sightly negative relation with $Ta_2O_3$. Back-scattered electron microscope images (BEI) of fergusonite show the mineral composition and textural feature is very complicated. The variation of Nb, Th and REE content of fergusonite and the modes of occurrence of mineral, suggests that REE may have been mobilized during the circulation of hydrothermal fluids related to contact metamorphism (metasomatism). The chemical variation of the fergusonites with occurrences and mineral association can be related to metasomatism of alkaline fluid was probably the dominant ore-forming process in Chungju district.

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The Operational Characteristics of CO2 5 ton/day Absorptive Separation Pilot Plant (이산화탄소 5 ton/day 흡수분리 Pilot Plant 운전 특성)

  • O, Min-Gyu;Park, So-Jin;Han, Keun-Hee;Lee, Jong-Seop;Min, Byoung-Moo
    • Korean Chemical Engineering Research
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    • v.50 no.1
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    • pp.128-134
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    • 2012
  • The pilot scale experiments can handle the flue gas up to 1,000 $Nm^3/hr$ for separation of carbon dioxide included in real flue gas at coal-fired power plant. The operational characteristics was analyzed with the main experimental variables such as flue gas flow rate, absorbent circulation rate using chemical absorbents mono-ethanolamine( MEA) and 2-amino-2-methyl-1-propanol(AMP). The more flue gas flow rate decreased in 100 $m^3/hr$ in the MEA 20 wt% experiments, the more carbon dioxide removal efficiency was increased 6.7% on average. Carbon dioxide removal efficiency was increased approximately 2.8% according to raise of the 1,000 kg/hr absorbent circulation rate. It also was more than 90% at $110^{\circ}C$ of re-boiler temperature. Carbon dioxide removal efficiency of the MEA was higher than that of the AMP. In the MEA(20 wt%) experiment, carbon dioxide removal efficiency(85.5%) was 10% higher than result(75.5%) of ASPEN plus simulation.

An Analysis of the Improvement of Food Labelling Standard based on Consumerism (소비자주의(消費者主義)에 입각(立脚)한 식품(食品)의 표시제도(表示制度) 개선(改善)에 관한 연구(硏究))

  • Nam, Sang-Duck
    • Journal of the Korean Society of Food Culture
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    • v.3 no.2
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    • pp.211-217
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    • 1988
  • The Main objective of this study is to find consumer attitude toward the Sanitary Regulation of Foods. In view of consumerism, this result will be used in re-regulating the law. Among the Sanitary Regulation of Foods, this study focuses on the Standard of prepackaged Food Labelling, because it is related both with the advertising from the food manufacturer's point of view and with the perception about the food itself from the consumer's point of view. After reviewing the previous studies and related provisions about the Standard of Prepackaged food Labelling, and compare other sanitary regulation of foods in developed countries (U.S.A. and Japan), basic research framework was derived. The research framework focuses on the user perception about the validity of provisions about the Standard of Prepackaged Food Labelling, and on the existance of exaggeration in food advertising using prepackaged foods. Data were collected through questionaires from the sample covering 374 food customers. The data were analyzed by frequency test and the important findings of this study are as follows. Most food consumers consider such provisions as date of manufacturing, circulation time limit, cautions for food handling, price, and manufacturer as important factors in buying food products. Among these factors, the date of manufacturing and circulation time limit are most critical factors, and must be labelled correctly on the prepackaged food cover. But other provisions which do not affect on consumer's buying decision (e.g. business admission number, self standard number) need not be labelled. From this study, we can conclude that the provisions about the standard of prepackaged Food Labelling currently used must be devided into two parts. One is 'mandatory provisions' which must be obeyed by all food manufacturets, and the other is 'autonomous provisions' which need not be obeyed by all food manufacturers. And mandatory provisions need to be regylated more strongly than now.

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The effects of activated cooler power on the transient pressure decay and helium mixing in the PANDA facility

  • Kapulla, R.;Paranjape, S.;Fehlmann, M.;Suter, S.;Doll, U.;Paladino, D.
    • Nuclear Engineering and Technology
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    • v.54 no.6
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    • pp.2311-2320
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    • 2022
  • The main outcomes of the experiments H2P6 performed in the thermal-hydraulics large-scale PANDA facility at PSI in the frame of the OECD/NEA HYMERES-2 project are presented in this article. The experiments of the H2P6 series consists of two PANDA tests characterized by the activation of three (H2P6_1) or one (H2P6_2) cooler(s) in an initially stratified and pressurized containment atmosphere. The initial stratification is defined by a helium-rich region located in the upper part of the vessel and a steam/air atmosphere in the lower part. The activation of the cooler(s) results i) in the condensation of the steam in the vicinity of the cooler(s), ii) the corresponding activation of large scale natural circulation currents in the vessel atmosphere, with the result of iii) the re-distribution and mixing of the Helium stratification initially located in the upper half of the vessel and iv) the continuous pressure decay. The initial helium layer represents hydrogen generated in a postulated severe accident. The main question to be answered by the experiments is whether or not the interaction of the different, localized cooler units would be important for the application of numerical methods. The paper describes the initial and boundary conditions and the experimental results of the H2P6 series with the suggestion of simple scaling laws for both experiments in terms of i) the temperature difference(s) across the cooler(s), ii) the transient steam and helium content and iii) the pressure decay in the vessel. The outcomes of this scaling indicate that the interaction between separate, closely localized units does not play a prominent role for the present experiments. It is therefore reasonable to model several units as one large component with equivalent heat transfer area and total water flow rate.