• 제목/요약/키워드: fluid and flow

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A Study on Food Cures for Constipations (대변불통에 활용된 식치방 연구)

  • Hong, Jin-im
    • Journal of Korean Medical classics
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    • v.31 no.1
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    • pp.29-43
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    • 2018
  • Objectives : This paper studies how the people of the past deal with constipation before the introduction of modern medical knowledge. Then, the paper selected some of the methods that use food ingredients with little to no side effects, and studied them to find a basic set of data that can be applied to today's medical practices. Methods : This paper reviewed six literatures: China's Eumsunjungyo, Nonohangeon, and Shiggamboncho, and Chosun's Singnyochanyo, Donguibogam, and Jejungsinpyeon. The food cures related to constipation were studied to discover what ingredients and preparation forms were used, how they were taken, what types of prescriptions existed, and how they were applied. Results : The food cure for constipation included ingredients such as mazi, suzi, sesame, honey, yiyiren, yuliren, xingren, taoren, and rice. These ingredients are known for replenishing the body's fluid and humor and allowing the better flow of qi. Mazi porridge, suma porridge, raw sesame oil, suzhu porridge, and suxing porridge were effective in dealing with the conspitation caused by heat, and jingshen wan, yiyiren porridge, yuliren porridge, yulirenyiyiren porridge, xingren porridge, and taoren porridge were effective in taking care of conspitation caused by qi deficiency. Conclusions : With a constipation caused by heat, it is good to take mazi and spinach regularly which is helpful in cooling down the heat. For senior citizens, constipations occur due to the qi deficiency that leads to the lack of fluid and humor. In this case, suzhu porridge should be taken regularly together with milk and sesame oil in order to replenish the qi. This will tonify the amount of qi and moisten the large intestines, which will be also helpful in tonifying the body itself.

Performance Analysis of Solar Thermal System with Heat Pump for Domestic Hot Water and Space Heating (온수 급탕 및 난방을 위한 히트 펌프 태양열 시스템의 성능 분석)

  • Sohn, Jin-Gug
    • Journal of the Korean Solar Energy Society
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    • v.38 no.5
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    • pp.49-62
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    • 2018
  • This study aims to analyze the performance of solar thermal system with heat pump for domestic hot water and heat supply. There are four types of system. Systems are categorized based on the existence of a heat pump and the ways of controlling the working fluid circulating from the collector. Working fluid is controlled by either temperature level (categorized as system 1 and 2) or sequential flow (system 3 and 4). Heat balance of the system, the solar fraction, hot water and heating supply rates, and performance of heat pump are analyzed using TRNSYS and TESS component programs. Technical specifications of the main facilities are as follow; the area of the collector to $25m^2$, the volumes of the main tank and the buffer tank to $0.5m^3$ and $0.8m^3$, respectively. Heating capacity of the heat pump in the heating mode is set to 30,000 kJ / hr. Hot water supply set 65 liters per person each day, total heat transfer coefficient of the building to 1,500 kJ / kg.K. Indoor temperature is kept steadily around $22^{\circ}C$. The results are as follows; 6 months average solar fraction of system 1 turns out to be 39%, which is 6.7% higher than system 2 without the heat pump, indicating a 25% increase of solar fraction compared to that of system 2. In addition, the solar fraction of system 1 is 2% higher than that of system 3. Hot water and heating supply rate of system 1 are 93% and 35%, respectively. Considering the heat balance of the system, higher heat efficiency, and solar fraction, as whole, it can be concluded that system 1 is the most suitable system for hot water and heat supply.

Characteristics and Clinical Outcomes of Cancer Patients who Developed Constrictive Physiology After Pericardiocentesis

  • Hyukjin Park;Hyun Ju Yoon;Nuri Lee;Jong Yoon Kim;Hyung Yoon Kim;Jae Yeong Cho;Kye Hun Kim;Youngkeun Ahn;Myung Ho Jeong;Jeong Gwan Cho
    • Korean Circulation Journal
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    • v.52 no.1
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    • pp.74-83
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    • 2022
  • Background and objectives: This study aimed to identify the characteristics and clinical outcomes of cancer patients who developed constrictive physiology (CP) after percutaneous pericardiocentesis. Methods: One-hundred thirty-three cancer patients who underwent pericardiocentesis were divided into 2 groups according to follow-up echocardiography (CP vs. non-CP). The clinical history, imaging findings, and laboratory results, and overall survival were compared. Results: CP developed in 49 (36.8%) patients after pericardiocentesis. The CP group had a more frequent history of radiation therapy. Pericardial enhancement and malignant masses abutting the pericardium were more frequently observed in the CP group. Fever and ST segment elevation were more frequent in the CP group, with higher C-reactive protein levels (6.6±4.3mg/dL vs. 3.3±2.5mg/dL, p<0.001). Pericardial fluid leukocytes counts were significantly higher, and positive cytology was more frequent in the CP group. In baseline echocardiography before pericardiocentesis, medial e' velocity was significantly higher in the CP group (8.6±2.1cm/s vs. 6.5±2.3cm/s, p<0.001), and respirophasic ventricular septal shift, prominent expiratory hepatic venous flow reversal, pericardial adhesion, and loculated pericardial fluid were also more frequent. The risk of all-cause death was significantly high in the CP group (hazard ratio, 1.53; 95% confidence interval,1.10-2.13; p=0.005). Conclusions: CP frequently develops after pericardiocentesis, and it is associated with poor survival in cancer patients. Several clinical signs, imaging, and laboratory findings suggestive of pericardial inflammation and/or direct malignant pericardial invasion are frequently observed and could be used as predictors of CP development.

Numerical Simulation of Flow past Forced and Freely Vibrating Cylinder at Low Reynolds Number

  • Jung, Jae Hwan;Nam, Bo Woo;Jung, Dong-Ho
    • Journal of Advanced Research in Ocean Engineering
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    • v.3 no.4
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    • pp.165-173
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    • 2017
  • This study aims at validating simulations of the forced and freely vibrating cylinders at Reynolds number of approximately 500 in order to identify the capability of the CFD code, and to establish the analysis process of the vortex-induced vibration (VIV). The direct numerical and large eddy simulations were employed to resolve the various length scales of the vortices, and the morphing technique was used to consider a motion of the circular cylinder. For the forced vibration case, both in- and anti-phase VIV processes were observed regarding the frequency ratio. Namely, when the frequency ratio approaches to unity, the synchronization/lock-in process occurs, leading to substantial increases in drag and lift coefficients. This is strongly linked with the switch in timing of the vortex formation, and this physical tendency is consistent with that of Blackburn and Henderson (J. Fluid Mech., 1999, 385, 255-286) as well as force coefficients. For the free oscillation case, the mass and damping ratio of 50.8 and 0.0024 were considered based on the study of Blackburn et al. (J. Fluid Struct., 2000, 15, 481-488) to allow the direct comparison of simulation results. The simulation results for a peak amplitude of the cylinder and a shedding mode are reasonably comparable to that of Blackburn et al. (2000). Consequently, based on aforementioned results, it can be concluded that numerical methods were successfully validated and the calculation procedure was well established for VIV analysis with reasonable results.

A Study on the Continuity Expressed in Modern Fashion Design - Focusing on the Continuance Theory of H. Bergson and the Continuity theory of J. Deleuze - (현대 패션 디자인에 나타난 연속성 연구 - 베르그송의 지속 이론과 들뢰즈의 연속성 이론을 중심으로 -)

  • Yang, Hee-Young;Yang, Sook-Hi
    • Journal of the Korean Society of Costume
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    • v.58 no.2
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    • pp.15-33
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    • 2008
  • Continuity and discontinuity is a relative concept, and there are various categories of the continuity and discontinuity in our circumference. Generally, characteristics of postmodernism including between the difference and the variety have being regarded as a discontinuity. Concept of the continuity includes between the quantitative continuity and the qualitative continuity qualitative continuity has organic characteristic, which encourages creating something permanently through the flowing of the time. Therefore, this thesis has studied like this complex social condition and various relationships expressed in modern fashion focusing on permanently creative movements and behaviors equal to the 'continuance' theory of Herni Bergson and 'continuity' theory of Jill Deleuze. This thesis classifies characteristics of the qualitative continuity into spatiotemporal and spatial continuity, and subdivides into 3 sets: perceptual continuity, spatial continuity, transferring continuity of physical experience, immaterial informational continuity, and fluid continuity with environment. Continuous viewpoint, which accepts the existing elements and allows them to flow liberally, should be present more appropriative thinking direction in explaining the complex situation expressed in the modern fashion, rather than discontinuous viewpoints focused on the only changing moment.

A Study on the Thermal Flow Analysis for Heat Performance Improvement of a Wireless Power Charger (열 유동해석을 통한 무선충전기 발열 성능 향상에 관한 연구)

  • Kim, Pyeong-Jun;Park, Dong-Kyou
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.310-316
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    • 2019
  • In automotive application, customers are demanding high efficiency and various functions for convenience. The demand for these automotive applications is steadily increasing. In this study, it has been studied the analysis of heat flow to improve the PCB(printed circuit board) heating performance of WPC (wireless power charger) recently developed for convenience. The charging performance of the wireless charger has been reduced due to power dissipation and thermal resistance of PCB. Therefore, it has been proposed optimal PCB design, layout and position of electronic parts through the simulation of heat flow analysis and PCB design was analyzed and decided at each design stage. Then, the experimental test is performed to verify the consistency of the analysis results under actual environmental conditions. In this paper, The PCB modeling and heat flow simulation in transient response were performed using HyperLynx Thermal and FloTHERM. In addition, the measurement was performed using infrared thermal imaging camera and used to verify the analysis results. In the final comparison, the error between analysis and experiment was found to be less than 10 % and the heating performance of PCB was also improved.

Development of Riverbank Filtration Water Supply and Return System for Sustainable Green House Heating and Cooling (지속가능 온실 냉난방을 위한 강변여과수 취수 및 회수시스템 개발)

  • Cho, Yong;Kim, Dae-Geun;Kim, Hyoung-Soo;Moon, Jong-Pil
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.2
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    • pp.20-29
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    • 2012
  • The green house on the waterfront is air-conditioned by a water-source heat pump system with riverbank filtration water. In order to supply riverbank filtration water in alluvium aquifer, the riverbank filtration facility for water intake and recharge, two pumping wells and one recharge well, has been constructed. The research site in Jinju, Korea was chosen as a good site for riverbank filtration water supply by the surface geological survey, electrical resistivity soundings, and borehole surveys. In the results of two boreholes drilling at the site, it was revealed that the groundwater table is about 3 m under the ground, and that the sandy gravel aquifer layer in the thickness of 6.5 m and 3.5 m occurs at 5 m and 7 m in depth below the ground level respectively. To prevent the recharge water from affecting the pumped water which might be used as heat source or sink, the distance between pumping and recharge wells is designed at least 70 m with a quarter of recharged flow rate. It is predicted that the transfer term, the recharge water affects the pumping well, is over 6 months of heating season. Hydrogeological simulation and underground water temperature measurement have been carried out for the pumping and recharge well positions in order to confirm the capability of sustainable green house heating and cooling.

Role of Catheter's Position for Final Results in Intrathecal Drug Delivery. Analysis Based on CSF Dynamics and Specific Drugs Profiles

  • De Andres, Jose;Perotti, Luciano;Villanueva, Vicente;Asensio Samper, Juan Marcos;Fabregat-Cid, Gustavo
    • The Korean Journal of Pain
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    • v.26 no.4
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    • pp.336-346
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    • 2013
  • Intrathecal drug delivery is an effective and safe option for the treatment of chronic pathology refractory to conventional pain therapies. Typical intrathecal administered drugs are opioids, baclofen, local anesthetics and adjuvant medications. Although knowledge about mechanisms of action of intrathecal drugs are every day more clear many doubt remain respect the correct location of intrathecal catheter in order to achieve the best therapeutic result. We analyze the factors that can affect drug distribution within the cerebrospinal fluid. Three categories of variables were identified: drug features, cerebrospinal fluid (CSF) dynamics and patients features. First category includes physicochemical properties and pharmacological features of intrathecal administered drugs with special attention to drug lipophilicity. In the second category, the variables in CSF flow, are considered that can modify the drug distribution within the CSF with special attention to the new theories of liquoral circulation. Last category try to explain inter-individual difference in baclofen response with difference that are specific for each patients such as the anatomical area to treat, patient posture or reaction to inflammatory stimulus. We conclude that a comprehensive evaluation of the patients, including imaging techniques to study the anatomy and physiology of intrathecal environment and CSF dynamics, could become essential in the future to the purpose of optimize the clinical outcome of intrathecal therapy.

An Experimental Study on the Dispersion Characteristics of Seawater Injection Nozzle for Hull Cooling (선체냉각을 위한 해수분사노즐의 산포특성에 관한 실험 연구)

  • Yoon, Seoktae;Jung, Hoseok;Cho, Yongjin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.6
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    • pp.767-773
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    • 2017
  • Infrared stealth is an important technology for naval ships. This technology helps improve the anti-detection performance and survivability of naval ships. In general, the infrared signature of naval ships are categorized into internal and external heat source. External signature are generated by ship surface heating by solar flux as well as the complicated heat transfer process with the surrounding weather condition. Modern naval ships are equipped with seawater injection nozzles on the outside for nuclear, biological and, chemical, and these nozzles are used to control external signature. Wide nozzle placement intervals and insufficient injection pressure, however, have reduced seawater dispersion area. To address this problem, nozzle installation standards must be established. In this study, an actual-scale experimental system was implemented to provide the evidence for nozzle installation standards in order to reduce the infrared signature of naval ships. In addition, the environmental conditions of the experiment were set up through computational fluid dynamics considering the ocean climate data and naval ship management conditions of South Korea. The dispersion distance was measured using a high-resolution thermography system. The flow rate, pipe pressure, and dispersion distance were analyzed, and the evidence for the installation of seawater injection nozzles and operation performance standards was suggested.

Computational Fluid Dynamics for Enhanced Uniformity of Mist-CVD Ga2O3 Thin Film (Ga2O3초음파분무화학기상증착 공정에서 유동해석을 이용한 균일도 향상 연구)

  • Ha, Joohwan;Lee, Hakji;Park, Sodam;Shin, Seokyoon;Byun, Changwoo
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.4
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    • pp.81-85
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    • 2022
  • Mist-CVD is known to have advantages of low cost and high productivity method since the precursor solution is misting with an ultrasonic generator and reacted on the substrate under vacuum-free conditions of atmospheric pressure. However, since the deposition distribution is not uniform, various efforts have been made to derive optimal conditions by changing the angle of the substrate and the position of the outlet to improve the result of the preceding study. Therefore, in this study, a deposition distribution uniformity model was derived through the shape and position of the substrate support and the conditions of inlet flow rate using the particle tracking method of computational fluid dynamics (CFD). The results of analysis were compared with the previous studies through experiment. It was confirmed that the rate of deposition area was improved from 38.7% to 100%, and the rate of deposition uniformity was 79.07% which was higher than the predicted result of simulation. Particle tracking method can reduce trial and error in experiments and can be considered as a reliable prediction method.