• Title/Summary/Keyword: internal circulation

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Hydraulic Model Experiment on the Circulation in Sagami Bay, Japan (II) - Dependence of the Circulation Pattern on External and Internal Rossby Number in Baroclinic Rotating Model

  • Choo Hyo-Sang;Sugimoto Takasige
    • Fisheries and Aquatic Sciences
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    • v.5 no.1
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    • pp.5-20
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    • 2002
  • To investigate the effect of mechanical parameters on the circulation and its fluctuation in Sagami Bay, baroclinic model experiments were carried out by use of a two-layer source-sink flow in a rotating tank. In the experiment, a simple coastal topography with flat bottom was reproduced. The results show that the path of the Through Flow, which corresponds to the branch current of the Kuroshio, depends on external Rossby number (Ro) and internal Rossby number $(Ro^*)$, and divided into two regimes. For $Ro^*\leq1.0$ in which Rossby internal radius of deformation of the Through Flow is smaller than the width of the approaching channel, the current flows along the Oshima Island as a coastal boundary density current separated from the western boundary of the channel. For $Ro^*>1.0$ it changes to a jet flow along the western boundary of the channel, separated from the coast of Oshima Island. The current is independent on both Ro and Ro* in the regime of $Ro^*>1.0,\;Ro\geq0.06$ and $Ro^*\leq1.0,\;Ro\geq0.06$. The pattern of the cyclonic circulation in the inner part of the bay is also determined by Ro and Ro*. In case of $Ro^*\leq1.0$, frontal eddies are formed in the northern boundary of the Through Flow. These frontal eddies intrude into the inner part along the eastern boundary of the bay providing vorticity to form and maintain the inner cyclonic circulation. For $Ro^*>1.0$, the wakes from the Izu peninsula are superposed intensifying the cyclonic circulation. The pattern of the cyclonic circulation is divided into three types; 1) weak cyclonic circulation and the inner anticyclonic circulation $(Ro<0.12)$. 2) cyclonic circulation in the bay $(0.12\leq Ro<0.25)$. 3) cyclonic circulation with strong boundary current $(RO\geq0.25)$.

The Investigation of Literature about fever (발열(發熱)에 관(關)한 문헌적(文獻的) 고찰(考察) -(황제내경(黃帝內經)을 중심(中心)으로)-)

  • Gyun, Hyun;Jeong, Seung-Gi;Lee, Hyeong-Gu
    • The Journal of Internal Korean Medicine
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    • v.11 no.1
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    • pp.1-13
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    • 1990
  • We objerved the following results from The Yellow Emperior's Canon of Internal medicine through the investigation of literature about fever. 1. Fever is divieded two type asthenic fever sthenic heat and It accused two type of excess of Yang-exoganous heat, deficiency of Yin-internal fever 2. The cause of fever is divieded three type, exoganous cause, internal cause non-exoganouse and internal cause Among the cause of fever Exoganous cause is almost affected by cold-evil Internal cause is affected by deficiency of Yin and seven emotion caused by having sex after intoxigation or over-exertion, and non-exoganous and internal cause bring about the difference of a personal life and food and drink 3. The sympton produced by fever is appeared differently through-pulse and meridian and they are indication of Diagnosis 4. The theory of treatment about fever are as follows Drinking cold-water Practising acupuncture Trerating hot-evil by cold Dispel cold by warm Treating cold-evil by heat Promote vital energy circulation by cold Treating warm-evil by cold Promating circulation by cold Treating cold-evil by warm Promoting circulation by heat.

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Hybrid Coronary Artery Revascularization for Takayasu Arteritis with Major Visceral Collateral Circulation from the Left Internal Thoracic Artery

  • Sim, Hyung Tae;Kim, Jeong-Won;Yoo, Jae Suk;Cho, Kwang Ree
    • Journal of Chest Surgery
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    • v.50 no.2
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    • pp.105-109
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    • 2017
  • Coronary arterial involvement in Takayasu arteritis (TA) is not uncommon. Herein, we describe a case of TA with celiac trunk and superior mesenteric artery occlusion combined with coronary artery disease. Bilateral huge internal thoracic arteries (ITAs) and the inferior mesenteric artery provided the major visceral collateral circulation. After percutaneous intervention to the right coronary artery, off-pump coronary artery bypass grafting for the left coronary territory was done using a right ITA graft and its large side branch because of its relatively minor contribution to the visceral collateral circulation.

The Internal Finishing Characteristics of Pipe Polished by Slurry Circulation Magnetic Abrasive Machining (슬러리순환 자기연마법에 의한 파이프 내면의 연마특성)

  • Rho, T.W.;Park, W.K.;You, W.S.;Seo, Y.I.;Choi, H.;Lee, J.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.198-201
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    • 2002
  • An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, a slurry circulation system was designed and manufactured. Its finishing characteristics was experimently investigated by various effective factors such as dry, water flow, oil flow with a slurry. From the experimental results, it was found that the materal removal and surface roughness were good in oil flow with slurry. The slurry circulation system is effective on the internal finishing of non-ferromagnetic pipe(SUS304).

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A Case of Inferior Vena Cava Obstruction Accompanying Pericardiacophrenic Collateral Circulation (심막횡격정맥 측부순환을 동반한 하대정맥 폐쇄 1예)

  • Kim, Jeong-Su;Han, Seong-Hoon;Song, Young-Soo;Jeon, Woo-Ki;Yum, Ho-Kee;Choi, Soo-Jeon;Lee, Bong-Choon
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.5
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    • pp.787-792
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    • 1995
  • The obstruction of inferior vena cava(IVC) is uncommon condition. The classification is based on the obstructive sites of major anatomic segments of IVC. The main collateral pathways of interruption of IVC were central channels through ascending lumbar veins, intervertebral veins and azygos-hemiazygos complex. However, the complete obstruction of mid-portion of IVC, accompanying collateral cirulation with pericardiacophrenic vein was rarely reported. We had experienced a case of complete obstruction of mid-portion of IVC with lobulated left cardiac border, which was unforgettable characteristic finding on chest radiograph. It was confirmed by venographic examination that the lobulated left cardiac shadow was a collateral circulation of pericardiacophrenic vein.

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A Case Report on Posterior Circulation Cerebral Infarction with Early Neurological Deterioration in an Elderly Patient with Chronic Kidney Disease (고령의 만성콩팥병 환자에서 발생한 초기 신경학적 악화가 동반된 후방순환뇌경색 치험 1례)

  • Kim, Jun-seok;Lee, Yoo-na;An, Yu-min;Baek, Kyung-min
    • The Journal of Internal Korean Medicine
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    • v.42 no.5
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    • pp.727-737
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    • 2021
  • Objectives: This study investigated the effect of Korean medicine on an elderly patient with posterior circulation cerebral infarction, chronic kidney disease (CKD), and early neurological deterioration (END). Methods: The patient, who already had CKD, was treated with Korean medicine, comprising herbal medicine, acupuncture, moxa, and cupping combined with Western medicine (antiplatelet, diabetes) and physical therapy. A manual muscle test (MMT) and a modified Barthel index (MBI) were used to observe the treatment effects, and blood tests were performed to check estimated glomerular filtration rate (eGFR), creatinine and blood urea nitrogen (BUN), which represent renal function. Results: After the treatment, MMT, MBI, and renal function scores had increased. Conclusions: This study suggests that Korean medicine can effectively treat posterior circulation cerebral infarction with END in CKD, but further studies should be conducted.

Characteristics of Atmospheric Circulation in Sokcho Coast (속초연안에서 대기순환의 특성)

  • Choi Hyo
    • Journal of Environmental Science International
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    • v.14 no.1
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    • pp.41-51
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    • 2005
  • Using three-dimensional non-hydrostatical numerical model with one way double nesting technique, atmo­spheric circulation in the mountainous coastal region in summer was investigated from August 13 through 15, 1995. During the day, synoptic westerly wind blows over Mt. Mishrung in the west of a coastal city, Sokcho toward the East Sea, while simultaneously, easterly upslope wind combined with both valley wind from plain (coast) toward mountain and sea-breeze from sea toward inland coast blows toward the top of the mountain. Two different directional wind systems confront each other in the mid of eastern slope of the mountain and the upslope wind goes up to the height over 2 km, becoming an easterly return flow in the upper level over the sea and making sea-breeze front with two kinds of sea-breeze circulations of a small one in the coast and a large one in the open sea. Convective boundary layer is developed with a thickness of about 1km over the ground in the upwind side of the mountain in the west and a thickness of thermal internal boundary layer from the coast along the eastern slope of the mountain is only confined to less than 200 m. On the other hand, after sunset, no prohibition of upslope wind generated during the day and downward wind combined with mountain wind from mountain towardplain and land-breeze from land toward under nocturnal radiative cooling of the ground surfaces should intensify westerly downslope wind, resulting in the formation of wind storm. As the wind storm moving down along the eastern slop causes the development of internal gravity waves with hydraulic jump motion in the coast, bounding up toward the upper level of the coastal sea, atmospheric circulation with both onshore and offshore winds like sea-breeze circulation forms in the coastal sea within 70 km until midnight and after that, westerly wind prevails in the coast and open seas.

Conceptual design of small modular reactor driven by natural circulation and study of design characteristics using CFD & RELAP5 code

  • Kim, Mun Soo;Jeong, Yong Hoon
    • Nuclear Engineering and Technology
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    • v.52 no.12
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    • pp.2743-2759
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    • 2020
  • A detailed computational fluid dynamics (CFD) simulation analysis model was developed using ANSYS CFX 16.1 and analyzed to simulate the basic design and internal flow characteristics of a 180 MW small modular reactor (SMR) with a natural circulation flow system. To analyze the natural circulation phenomena without a pump for the initial flow generation inside the reactor, the flow characteristics were evaluated for each output assuming various initial powers relative to the critical condition. The eddy phenomenon and the flow imbalance phenomenon at each output were confirmed, and a flow leveling structure under the core was proposed for an optimization of the internal natural circulation flow. In the steady-state analysis, the temperature distribution and heat transfer speed at each position considering an increase in the output power of the core were calculated, and the conceptual design of the SMR had a sufficient thermal margin (31.4 K). A transient model with the output ranging from 0% to 100% was analyzed, and the obtained values were close to the Thot and Tcold temperature difference value estimated in the conceptual design of the SMR. The K-factor was calculated from the flow analysis data of the CFX model and applied to an analysis model in RELAP5/MOD3.3, the optimal analysis system code for nuclear power plants. The CFX analysis results and RELAP analysis results were evaluated in terms of the internal flow characteristics per core output. The two codes, which model the same nuclear power plant, have different flow analysis schemes but can be used complementarily. In particular, it will be useful to carry out detailed studies of the timing of the steam generator intervention when an SMR is activated. The thermal and hydraulic characteristics of the models that applied porous media to the core & steam generators and the models that embodied the entire detail shape were compared and analyzed. Although there were differences in the ability to analyze detailed flow characteristics at some low powers, it was confirmed that there was no significant difference in the thermal hydraulic characteristics' analysis of the SMR system's conceptual design.