• Title/Summary/Keyword: Inner Flows

Search Result 179, Processing Time 0.035 seconds

A Study on the Lineage of Medicine in the Middle Period of the Chosun Dynasty (조선중기(朝鮮中期) 의학(醫學)의 계통(系統)에 관(關)한 연구(硏究))

  • Kim, Hong-Kyoon;Park, Chan-Kuk
    • Journal of Korean Medical classics
    • /
    • v.5
    • /
    • pp.252-305
    • /
    • 1992
  • The Korean Medicine in the middle period of the Chosun Dynasty, with its clear independence, has made an excellent display of originality and superiority in the world medicine. By pinpointing its merits, classifying its lineal descent, and examining its relation with present Korean Medicine we can draw the following conclusions. First, the study on the history of Korean Medicine should, in terms of time, grasp the generational stream and, in terms of space, examine the relation with medicines of neighbouring countries, with both an inner and outer way of observing. Secondly, it is but a manifestation of the colonial view of history to classify the 460 years from Tae-jo(太祖) to Cheol-jong(哲宗) as Mordern Period of Korean Medicine. Therefore, the 250-year period between the mid-16th century of Myung-jong(明宗) to the late-18th century of later Jeong-jo(正祖), which saw a pivotal development of the national medicine as a practical medicine based on experiences, should be established as the period of Korean Medicine in the mid-Chosun dynasty. It is required from both nationalistic view of history and history as a positive science. Thirdly, Korean Medicine in the mid-Chosun period was developed with an emphasis on an independent development and creative succession of the national medicine, which was succeeded to the late-Chosun period. Fourthly, medical thought in the mid-Chosun period was much influenced by, and based on the practicality of, Shil-hak(or practical science : 實學) as was the current of the times. Fifthly, though medicine in the mid-Chosun period was generally developed, the recipes for the measles, epidemic and smallpox were especially developed owing to rage of epidemics, and the development of the acupunture as a military medicine was the most c lear because of the two major wars against the Japanese and Chinese, respectively in 1592 and 1636. Sixthly, Whang doh-yeon(黃道淵)'s Bangyak-happyeon(方藥合編), Lee je-mah(李濟馬)'s Tongui-susebawon(東醫壽世保元) and Lee kyu-jun(李奎晙)'s Uigam-jungma(醫鑑重磨) are representative medical books, in the late-Chosun period, which creatively succeeded national medicine. Seventhly, the lineage of national medicine flows from Hyangyak-jipseongbang(鄕樂集成方) Uibangryuchui(醫方類聚) Gugeupbang(救急方) to Uirimchualyo(醫林撮要) Tonguibogam(東醫寶鑑) Uimunbogam(醫門寶鑑) Jejung-sinpyeon(濟衆新編) and to Bangyak-happyeon(方藥合編) Tongui-susebawon(東醫壽世保元) Uigam-jungma(醫鑑重磨). These books are representative medical books in the early middle and late Chosun period respectively. On the basis of the above facts, it is clear that the orthodoxy of national medicine is in the direction of a creative succession and that is the best way to keep the spirit of Korean medicine today.

  • PDF

Vertical Upward Air-Water Two-Phase Flow Regime Identification (수직상향류 공기-물 이상유동영역 판별)

  • Lee, Ba-Ro;Jang, Young-Jun;Ko, Min-Seok;Lee, Bo-An;Lee, Yeon-Gun;Kim, Sin
    • Journal of Energy Engineering
    • /
    • v.22 no.4
    • /
    • pp.362-369
    • /
    • 2013
  • Two-phase flow is frequently observed in many industries such as nuclear power plants and oil transportation. Two-phase flow regime depends on the flow rates, the fluid properties and the structure of flow channels. Since the identification of the flow regime is of great importance in the system design and the safety analysis, a number of theoretical and experimental investigations have been performed. This paper presents a basic research on the characteristics of each flow regime and transition boundary in the two-phase flows. The flow regime of the upward air-water flow in the vertical tube, 30 mm in the inner diameter, is distinguished by using the high-speed camera and the Wire-mesh sensor(WMS). The identified experimental data are compared with the flow regime maps proposed by Taitel et al, Mishima and Ishii. Even though there is slight difference in the transition boundary, the experimental data show general agreement with these flow regime maps.

The Study on the Wave Pressure of the Tsunami Acting on the Permeable Structure (투과성구조물에 작용하는 지진해일파압에 관한 연구)

  • Lee, Kwang-Ho;Choi, Hyun-Seok;Kim, Chang-Hoon;Kim, Do-Sam;Cho, Sung
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.23 no.1
    • /
    • pp.79-92
    • /
    • 2011
  • In this study, wave pressure of short-period gravity waves and tsunami acting on the upright section of the horizontal-slit type caisson placed on the impermeable or permeable seabed, which is a well-known permeable breakwater with a good wave controlling ability, are investigated via numerical simulations. Further, the permeable seabed was modeled as the porous media with porosity of 0.4. Using the numerical results, the effects of the seabed conditions on the wave pressure on the front wall and inside wall of the chamber have been studied. In the numerical simulations, short-period gravity waves and tsunami(solitary wave or bore) with the same amplitude to the gravity wave are considered. A numerical wave tank is used, which is able to consider a gas-liquid two-phase flow in the same calculation zone. Numerical results show that the wave pressure of the tsunami was 3~5 times higher than the short-period gravity waves acting on the front wall and it was 2~4 times higher than the short-period gravity waves acting on the inner wall.

Numerical Analysis of Resin Filling Process for a Molded Dry-type Potential Transformer (몰드형 건식 계기용 변압기 제작을 위한 수지 충진 해석 연구)

  • Kim, Moosun;Jang, Dong Uk;Kim, Seung Mo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.12
    • /
    • pp.511-517
    • /
    • 2016
  • Current oil-type potential transformers for trains are filled with insulating oil, which could have problems like explosions due to rising inner pressure during train operation. Therefore, mold and dry-type potential transformers are being developed to prevent explosions. One problem in manufacturing mold-type transformers is preventing void formation around the coiled core inside the mold during epoxy filling, which could cause an electrical spark. Micro voids can remain in the resin after filling, and macro voids can occur due to the structure shape. A transformer that is being developed has a cavity at the junction of the core and the coil for better performance, and when highly viscous epoxy flows inside the cavity channel, macro voids can form inside it. Therefore, in this study, the free-surface flow of the mold filling procedure was analyzed numerically by applying the VOF method. The results were used to understand the phenomena of void formation inside the cavity and to modify the process conditions to reduce voids.

Modeling for Pollution Contribution Rate of Land based Load in Masan Bay (마산만 육상기인오염원의 오염기여율 모델링)

  • Jung, Woo-Sung;Hong, Sok-Jin;Lee, Won-Chan;Kim, Hyung-Chul;Kim, Jin-ho;Kim, Dong-Myung
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.22 no.1
    • /
    • pp.59-66
    • /
    • 2016
  • Pollution contribution rate that is effect on water quality from land based load in Masan bay was showed quantifiably for coastal water quality management by using ecological model. It was calculated by difference of water quality concentration at each points t hat is calculated by each scenarios that are presence or absence of each sources (16 points). Results show that, rivers of Northern Masan bay contributed in Masan bay COD is 20 %, T-P is 62 % at northern part and COD is 10 %, T-P is 16 % at middle part. As a result, rivers of Northern Masan bay had effect on water quality of northern Masan bay and middle Masan bay. Also, T-P load affects water quality bigger than COD load, because T-P contribution rate bigger than COD contribution rate of northern rivers. Dukdong WTTP that is land pollution source of southern Masan bay contributed in Masan bay COD is 26 %, T-P is 11% at middle part, COD is 17 %, T-P is 7 % at middle part and COD is 10 %, T-P is 1 % at outer part. It affects water quality bigger at southern and middle of Masan bay than outer bay, because residual flow of bottom flows toward inner of Masan bay nearby Dukdong WTTP.

Experimental Study on Coefficient of Flow Convection (유수대류계수에 관한 실험적 연구)

  • Jeon, Sang-Eun;Kim, Kook-Han;Kim, Jin-Keun;Yang, Joo-Kyoung
    • Journal of the Korea Concrete Institute
    • /
    • v.15 no.2
    • /
    • pp.314-322
    • /
    • 2003
  • Pipe cooling method is widely used for reduction of hydration heat and control of cracking in mass concrete structures. However, in order to effectively apply pipe cooling systems to concrete structures, the coefficient of flow convection relating the thermal transfer between inner stream of pipe and concrete must be estimated. In this study, a device measuring the coefficient of flow convection was developed. Since a variation of thermal distribution caused by pipe cooling has a direct effect on internal forced flows, the developed testing device is based on the internal forced flow concept. Influencing factors on the coefficient of flow convection are mainly flow velocity, pipe diameter and thickness, and pipe material. Using experimental results from the developed device, the coefficient of flow convection was calculated. Finally, a general prediction model was proposed by theoretical procedures. The proposed prediction model is able to estimate the coefficient of flow convection with flow velocity and material properties of pipe. From comparison with experimental results, the coefficient of flow convection by this model was well agreed with those by experimental results.

Experimental Study of Friction Factors for Laminar, Transition, and Turbulent Flow Regimes in Helical Coil Tubes (헬리컬 코일 튜브에서의 층류, 천이, 난류 영역의 마찰계수에 대한 실험적 연구)

  • Park, Won Ki;Kim, Taehoon;Do, Kyu Hyung;Han, Yong-Shik;Choi, Byung-Il
    • Journal of the Korean Society of Safety
    • /
    • v.33 no.1
    • /
    • pp.7-15
    • /
    • 2018
  • The friction factors according to the flow regimes in helical coil tubes depend on the coil diameter, the tube diameter, and the coil pitch. In previous studies, correlations for the laminar flow regime in helical coil tubes have been proposed. However, studies on the transition flow regime and the turbulent flow regime are insufficient and further researches are necessary. In this study, characteristics of the friction factors for the laminar, transition and turbulent flow regimes in helical coil tubes were experimentally investigated. The helical coil tubes used in the experiments were made of copper. The curvature ratios of the helical coil tubes, which means the ratio of helical coil diameter to inner diameter of the helical coil tube are 24.5 and 90.9. Experiments were carried out in the range of $529{\leq}Re{\leq}39,406$ to observe the flows from the laminar to the turbulent regime. The friction factors were obtained by measuring the differential pressures according to the flow rates in the helical coil tubes while varying the curvature ratios of the helical coil tubes. Experimental data show that the friction factors for the helical coil tube with 24.5 in the curvature ratio of the helical coil tube were larger than those in the straight tube in all flow regimes. As the curvature ratio of the helical coil tube increases, the friction factor in turbulent flow regime tends to be equal to that of the straight tube. In addition, it was confirmed that the transition flow regimes in the helical coil tubes were much wider than those in the straight tube, also the critical Reynolds numbers were larger than those in the straight tube. The results obtained in this experimental study can be used as basic data for studies on the water hammer phenomenon in helical coil tubes.

Optimum Design of Rubber Injection Molding Process (고무사출성형의 적정설계)

  • Lee, Eun-Ju;Lim, Kwang-Hee;Giang, Vu Tai
    • Korean Chemical Engineering Research
    • /
    • v.49 no.1
    • /
    • pp.47-55
    • /
    • 2011
  • The optimum mold design and the optimum process condition were constructed upon executing process simulation of rubber injection molding with the commercial CAE program of MOLDFLOW (Ver. 5.2) in order to solve the process-problems of K company relating to cracks, which occurs at the inner cavity wall of C. V. joint boots. As a result it was confirmed that the real cracks occurs at the exactly same position of the cavity as exhibits the defects of weld and meld line and unsatisfactory curing according to the result of simulation. In order to prevent the occurrence of weld and meld line at the defect-position, the location of gate was altered to the optimum position of the cavity. Consequently the filling pattern was established to minimize the degree of the melt-fronts confronting or the melt-flows melding to prevent the occurrence of weld and meld line at the defect-position. It was observed that both gate-positions to maximize the degree of the formation of weld and meld line and air traps are located, respectively, in opposite direction each other with reference to the optimum gate position. In addition, the temperature of mold was raised by $10^{\circ}C$ and maintained at $170^{\circ}C$ for satisfactory curing.

Origin and Developing Process of Ark-shell Culture Industry in Korea (우리나라 꼬막양식업의 발상과 발달과정)

  • BAE Su-Whan
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.19 no.1
    • /
    • pp.72-82
    • /
    • 1986
  • There were three important species among the marine organisms which were cultured in the inter tidal zone in the old days, and an ark-shell was one of them. Exaiming old books and reports concerning fishery were made in order to reveal the history and industrial trend of ark-shell culture. Ark-shell was called by the different names in the old days "Komak" and "Sohap". The name of Komak was originated in the southern coast area in the 1,700s, and from the begining of 18 century Komak was used only. Ark-shell was produced in all southern and western coast areas, where a little of fresh water flows into the calm inner sea and the intertidal zone is well developed. It was well known that ark-shells shell as well as its flesh took the effect of a medicine. Its culturing method in Korea seems to be derived from China in the beginning of 19 century, it was cultured first at the southern area of Chollanam-do. It was considered as the side business, but after Korean war it is produced on the basis of cooperative work, now its production is quite increased (more than $5,000\fra{M}{T}$) due to the goverments development policy.

  • PDF

Thermal Environment Analysis for Preserving Ancient Mural Painting in Songsan-ri Tomb No. 6, Gongju, Korea (공주 송산리 6호 벽화고분 보존을 위한 온열환경 분석 연구)

  • Kim, Dae Woon;Jeong, Sun Hye;Lee, Min Young;Chung, Yong Jae
    • Journal of Conservation Science
    • /
    • v.32 no.4
    • /
    • pp.521-534
    • /
    • 2016
  • Ancient tombs are typically comprised of confined rooms, which have different spatial characteristics than the external environment because they are covered by heavy layers of soil. In this study, we examined the thermal energy flow from the outside to inside of Songsan-ri tomb No. 6. External heat flows slowly to the inside because of heavy soil layer, and the presence of several rooms and entrances. For this reason, it takes about two months for the air temperature to travel from the outside to the inside of the tomb. Interestingly, the gradational inflow of thermal energy from outside the tomb leads to delicate horizontal and vertical variations in the wall temperature. These micro-environmental differences occur in the inner tomb every year, so we can expect them to cause condensation with regularity. In addition, we show that the previously installed forced circulation air conditioning system risks fatal damage to the mural wall painting. The results of this research suggest an optimal air conditioning system and optimized space planning to conserve Songsan-ri tomb No. 6 and its mural painting.