• Title/Summary/Keyword: Flow failure

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A Case of Multiple Giant Coronary Aneurysms with Large Mural Thrombus due to Kawasaki Disease in a Young Infant (가와사끼병 영아에서 발생한 혈전을 동반한 거대관상동맥류 1례)

  • Choi, Eun Na;Kim, Jeoung Tae;Kim, Yuria;Yoo, Byung Won;Choi, Deok Young;Choi, Jae Young;Sul, Jun Hee;Lee, Sung Kye;Kim, Dong Soo;Park, Young Hwan
    • Clinical and Experimental Pediatrics
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    • v.48 no.3
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    • pp.321-326
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    • 2005
  • Kawasaki disease is an acute systemic vasculitis of unknown origin. Giant coronary aneurysm is one of the most serious complications, although peripheral artery vasculitis can produce life-threatening events. Myocardial ischemia and infarction can be caused by coronary artery stenosis, aneurysm, and stagnation of blood flow in coronary arteries which triggers thromboembolism. Atypical presentation in young infants often interferes with prompt diagnosis and timely treatment, resulting in poor outcomes. We describe a 3-month-old infant with multiple giant coronary aneurysms with flow stagnation, stenosis and large mural thrombus due to Kawasaki disease. He presented with a prolonged course of severe coronary involvement in spite of all measures to reduce coronary complications. Finally, surgical intervention was tried because of the worsening coronary artery abnormalities. The patient died of acute cardiorespiratory failure shortly after weaning from cardiopulmonary bypass.

Studies of Aleolar-Mixed Venous CO2 and O2 Gradients in the Rebreathing Dog Lung (반복호흡(反覆呼吸)을 하는 견폐(犬肺)에서의 폐포(肺胞)와 혼합정맥혈액(混合靜脈血液)의 CO2 및 O2 경사도(傾斜度)에 대한 연구(硏究))

  • Yu, Chang Jun
    • Korean Journal of Veterinary Research
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    • v.12 no.1
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    • pp.37-50
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    • 1972
  • Another comparison of alveolar gas pressures, in a continuously rebreathing dog lung, with pulmonary arterial (mixed venous) blood, again showed alveolar pressures to be the higher for $CO_2$ and usually $O_2$ (positive ${\Delta}Pco_2$, and ${\Delta}Po_2$). ${\Delta}Pco_2$ was almost invariably positive, it was independant of time and of plasma pH changes produced by acid or bicarbonate infusion, but proportional to blood $CO_2$ level. It was seemingly little affected by the distribution or magnitude of blood flow nor did it result from failure of $CO_2$ equilibrium within the blood, but it did rise with carbonic anhydrase inhibition. ${\Delta}Po_2$ was more variable and sometimes negative, particularly at low blood flow rates. It seemed in dependant of time, and plasma pH changes, apart from an inverse relationship with that resulting from $CO_2$ changes. It existed despite considerable potential for gas exchange, and was unaffected by inhibition of the $CO_2$ reactions.

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An Ethnographic Study on Middle aged Women's Hwa-Byung with Upper Limb Arthropathy (중년여성의 화병과 상지관절동통에 관한 문화기술지)

  • Kim, Mee-Young
    • Journal of East-West Nursing Research
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    • v.13 no.2
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    • pp.160-169
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    • 2007
  • Background: Hwa-Byung is known as a specific Korean cultural syndrome which corresponds to DSM-IV(MMPI). Some Korean women who have experienced heart aching anger(Hwa-Byung) complain physical pains as well as psychological problems. As for these physical pains, upper limb arthropathy(e.g. golf elbow pains, tennis elbow pains, or shoulder-joint pains) have not been paid attentions. In spite of not having done her excessive physical endeavor or exercise, some Korean middle aged women complain those arthropathy pains. And they go round orthopedics, pain clinics, and oriental medicine clinics. Purpose: This study was practiced in Severance Oriental Medicine Clinic. The oriental medicine doctor had a question about the major origin of upper limb pains which were not caused by excessive physical endeavor. To answer the question, this study has been practiced. In the process of interview with some those women, the major cause of those syndromes has been revealed as Hwa-Byung. The purpose of this study is to discover the meanings of the women's life who have been experienced Hwa-Byung with upper limb arthropathy. Results: These upper limb arthropathy can be explained by meridian theory. Shoulder-joint pain and golf elbow with Hwabyung can be explained by Heart meridian of hand-shoyin and the points of these pains are in the flow of this meridian. Tennis elbow with Hwabyung can be explained by Small intestine meridian of hand-taiyang and this point is in the flow of this meridian. The results of interview with 9 middle aged women was analyzed and interpreted according to Spradley's method of ethnography. The analysis revealed three core cultural themes : 1) There are certainly external cause to provoke Hwa-Byung. A patricentric family system, husband's playing around with another woman, cruel treatment by husband's family, or financial failure may be present anteriorly. 2) The chief existing condition is the discord between husband and wife. The stoppage of mutual communication, lacking in understanding, unfeeling, heartless, or unsympathetic is an major phenomenon of married life. So the important factor is not the sexual relations or problems but the discords of communication. 3) The feeling of anger, the sense of nihility, the desire to escape, and the effort to forgiveness coexist together. At a glance, they seemed to be a process. For example, anger seemed to present at first, then nihility seemed at second, then escape seemed at third, and then forgiveness seemed at last. But at point of visiting clinic to be treated, they are mixed up together as if in a jumble.

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Characterization on the Relationships among Rainfall Intensity, Slope Angle and Pore Water Pressure by a Flume Test : in Case of Gneissic Weathered Soil (산사태 모형실험을 통한 강우강도 및 사면경사 변화와 간극수압과의 관계 연구 : 편마암 풍화토를 대상으로)

  • Chae, Byung-Gon;Lee, Seong-Ho;Song, Young-Suk;Cho, Yong-Chan;Seo, Yong-Seok
    • The Journal of Engineering Geology
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    • v.17 no.1 s.50
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    • pp.57-64
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    • 2007
  • This study was conducted to characterize on the relationships among rainfall intensity, slope angle and pore water pressure in the gneissic weathered soil by landslide laboratory flume tests. Under the several test conditions dependent on rainfall intensity and slope angle, the authors measured pore water pressure, failure and displacement of slope on a regular time interval. According to the test results, the increasing times of pore water pressures have direct proportional trends to the rainfall intensity. The pore water pressure was increased earlier at the head part of slope than the toe part. Compared with the test results of Chae et al(2006), the results of this study explain that the seepage velocity in the gneissic weathered soil is slower than that in the standard sands. It results in faster and ear-lier increase of pore water pressure at the head part of slope due to slow flow of water in the gneissic weathered soil. In case of the relationship between slope angle and pore water pressure, gentle slope angle has faster increase of pore water pressure than steeper slope angle. It is also thought to be due to slow seepage velocity and flow velocity in the gneissic weathered soil.

Assessment of Viral Attenuation in Soil Using Probabilistic Quantitative Model (확률적 정량모델을 이용한 토양에서의 바이러스 저감 평가)

  • Park, Jeong-Ann;Kim, Jae-Hyun;Lee, In;Kim, Song-Bae
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.7
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    • pp.544-551
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    • 2011
  • The objective of this study was to analyze VIRULO model, a probabilistic quantitative model, which had been developed by US Environmental Protection Agency. The model could assess the viral attenuation capacity of soil as hydrogeologic barrier using Monte Carlo simulation. The governing equations used in the model were composed of unsaturated flow equations and viral transport equations. Among the model parameters, those related to water flow for 11 soil types were from UNDODA data, and those related to 5 virus species were from the literatures. The model compared the attenuation factor with threshold of attenuation to determine the probability of failure and presented the exceedances and Monte Carlo runs as output. The analysis indicated that among 11 USDA soil types, the viral attenuation capacity of loamy sand and sand were far lower than those of clay and silt soils. Also, there were differences in the attenuation in soil among 5 viruses with poliovirus showing the highest attenuation. The viral attenuation capacity of soil decreased sharply with increasing soil water content and increased nonlinearly with increasing soil barrier length. This study indicates that VIRULO model could be considered as a useful screening tool for viral risk assessment in subsurface environment.

Quality Grading of Concrete Soil Erosion Control Dam in the Aspect of Unconfined Concrete Strength by Surface-Wave Technique (표면파 기법에 의한 콘크리트 사방댐의 콘크리트 강도 등급 평가)

  • Lee, Chang-Woo;Joh, Sung-Ho;Park, Ki-Hyung;Kim, Min-Sik;Yoon, Ho-Joong;Raja Ahmad, Raja Hassanul
    • Journal of Korean Society of Forest Science
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    • v.101 no.3
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    • pp.412-425
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    • 2012
  • Concrete Soil Erosion Control Dam, which blocks flow of debris flow in torrential stream, are reported to lose expected functions due to structural failure and collapses, caused by poor construction, material deterioration and external impacts. In this paper, an integrity assessment technique for debris barriers was proposed, which allows preliminary detection of problems inherent in debris barriers. The proposed integrity assessment technique is a non-destructive method based on SASW method, one of surface-wave tests. In this paper, a practical procedure and analysis guidelines in applying the SASW technique to debris barrier was proposed and its validity was verified using five decrepit debris barriers older than 20-year old. As a result, the SASW method was validated for the reliable grade evaluation method for concrete soil erosion control dam, and the resulting grades turned out to agree with the results determined by Sabang Associations.

A Study on Stability of Levee Revetment in Meandering Channel (만곡수로 내의 호안 안정성 연구)

  • Kim, Sooyoung;Yoon, Kwang Seok;Kim, Hyung-Jun
    • Journal of Korea Water Resources Association
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    • v.48 no.12
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    • pp.1077-1087
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    • 2015
  • The levee protect lifes, houses, and properties by blocking overflow of river. The revetment is forced to be covered on the slope of levee in order to prevent erosion. The stability of revetment is very important enough to directly connected to the stability of levee. In this study, the weak points of revetment on meandering channel were found by movable revetment experiment and the velocity and the water surface elevation (WSE) were measured at main points. The 3-D numerical simulations were performed under same conditions with experiment. And unclear flow characteristics by the limit of measuring instruments were analyzed through numerical simulation. Consequently, the section of large wall shear stress and the failure section are almost the same. Despite of small wall shear stress, the revetments located at right bank were carried away because of circulation zone due to secondary flow by meandering. With existing riprap design formula, the sizes of riprap determined using maximum local velocity were 1.5~4.7 times greater than them using mean velocity. As a result of this study, it is necessary to calculate the size of riprap in other ways for meandering and straight channel. At a later study, if the weighted value considered the radius of curvature and shape of hydraulic structure is applied to riprap design formula, it is expected that the size of revetment was evaluated rationally and accurately.

Safety Index Evaluation from Resistivity Monitoring Data for a Reservoir Dyke (전기비저항 상시관측에 의한 제체 안전도 지수 산출)

  • Cho, In-Ky;Kang, Hyung-Jae;Lee, Byoung-Ho;Kim, Byoung-Ho;Yi, Sang-Sun;Park, Young-Gyu;Lee, Bo-Hyun
    • Geophysics and Geophysical Exploration
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    • v.9 no.2
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    • pp.155-162
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    • 2006
  • An abnormal seepage flow, which is mainly caused by the piping, is one of the major reasons for embankment dam failure. A leakage detection is therefore a vital part of an embankment dam's monitoring. Resistivity method, which is an efficient tool to detect leakage zones, has been used all over the world for an embankment dam's monitoring. Although the resistivity method gives us very useful information about the leakage problem, there is no more quantitative interpretation than the low resistivity zones in the 2-dimensional resistivity section are regraded simply as the anomalous seepage zones. Recently, resistivity monitoring technique is applied for the detection of leakage zones. However, its interpretation still remains in the stage of presenting the resistivity ratio itself. An increased seepage flow increases a porosity and an increasing porosity decreases the dam's stability. Therefore, the porosity is one of the major factors for an embankment dam's stability. Based on Archie's experimental formula, we try to evaluate a porosity distribution from the resistivity data which is obtained on the dam's crest. We also attempt to represent a procedure to evaluate a safety index of the embankment dam from the resistivity monitoring data.

Study on the Steam Line Break Accident for Kori Unit-1 (고리 1호기에 대한 증기배관 파열사고 연구)

  • Tae Woon Kim;Jung In Choi;Un Chul Lee;Ki In Han
    • Nuclear Engineering and Technology
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    • v.14 no.4
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    • pp.186-195
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    • 1982
  • The steam line break accident for Kori Unit 1 is analyzed by a code SYSRAN which calculates nuclear power and heat flux using the point kinetics equation and the lumped-parameter model and calculates system transient using the mass and energy balance equation with the assumption of uniform reactor coolant system pressure. The 1.4 f $t^2$ steam line break accident is analyzed at EOL (End of Life), hot shutdown condition in which case the accident would be most severe. The steam discharge rate is assumed to follow the Moody critical flow model. The results reveal the peak heat flux of 38% of nominal full power value at 60 second after the accident initiates, which is higher than the FSAR result of 26%. Trends for the transient are in good agreement with FSAR results. A sensitivity study shows that this accident is most sensitive to the moderator density coefficient and the lower plenum mixing factor. The DNBR calculation under the assumption of $F_{{\Delta}H}$=3.66, which is used in the FSAR with all the control and the shutdown assemblies inserted except one B bank assembly and of Fz=1.55 shows that minimum DNBR reaches 1.62 at 60 second, indicating that the fuel failure is not anticipated to occur. The point kinetics equation, the lumped-parameter model and the system transient model which uses the mass and energy balance equation are verified to be effective to follow the system transient phenomena of the nuclear power plants.lear power plants.

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Design and Evaluation of a Lung Assist Device for Patients with Acute Respiratory Syndrome using Hollow Fiber Membranes (중공사 막을 이용한 급성호흡곤란증후군 환자용 폐 보조 장치의 설계와 평가)

  • Lee, Sam-Cheol;Kwon, O-Sung;Kim, Ho-Cheol;Hwang, Young-Sil;Lee, Hyun-Cheol
    • Membrane Journal
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    • v.15 no.3
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    • pp.224-232
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    • 2005
  • The use of the lung assist device (LAD) would be well suited for acute respiratory failure (ARF) patients, combining the simplicity of mechanical ventilation with the ability of extracoporeal membrane oxygenators (ECMO) to provide temporary relief for the natural lungs. This study's specific attention was focused on the effect of membrane vibration in the LAD. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on blood hemolysis. We tried to decide upon excited frequency band of limit hemolysis when blood hemolysis came to through a membrane vibration action. The excited frequency of the module type 5, consisted of 675 hollow fiber membranes, showed the maximum gas transfer rate. We concluded that the maximum oxygen transfer rate seemed to be caused by the occurrence of maximum amplitude and the transfer of vibration to hollow fiber membranes. It was excited up to $25{\pm}5$ Hz at each blood flow rate of module type 5. We found that this frequency became the 2nd mode resonance riequency of the flexible in blood flow. Blood hemolysis was low at the excited frequency of $25{\pm}5$ Hz. Therefore, we decided that limit hemolysis frequency of this LAD was $25{\pm}5$ Hz.