• Title/Summary/Keyword: varied flow

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Effect of Various Moxibustions on Xiawan(CV10) on Gastric Function in Normal Rat (하완을 이용한 다양한 구(灸)자극 방법이 정상 백서의 위기능에 미치는 영향)

  • Han Kyung-Hee;Park Yong-In;Choi Wong-Jin;Park Won;Yu Yun-Cho;Kim Myung-Dong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.5
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    • pp.1344-1348
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    • 2005
  • Moxibustion treatment gives stimulus to specific points in the meridian distributed on the body, and controls imbalance of Qi, blood stream, and, Yin and Yang. So this treatment is the way that prevents and cures diseases by making meridian flow normal. Moxibustion stimulating conditions have a great influence on the treatment results. So proper standards of stimulus are needed to expect effective treatment results. To know what number of moxibustions are needed to gain good treatment effects, I observed the gastrin level in blood after moxibustion on the Xiawan(CV10). Gastrin stimulates to secrete gastric acid. The followings are the results. After 1, 5, and 10 moxibustions everyday on each rat for 5 days, 1 compared what number of moxibustion had a good effect. The group of 5 moxibustions every day had a more significant effect. After moxibustions of 1, 5, and 10 coagulated moxas on each rat, 1 compared the effect of the size of coagulated moxa. The group of 5 and 10 coagulated moxas had a more significant effect. After the same moxibustions on each ract for 1, 5, and 10 days, 1 compared the effect of moxibustion terms. The group of 5 days moxibustion had a more significant effect. These results say that the treatment effect of moxibustion can be varied by the choice of points, and the size, the time, and the number of moxibustions can bring out different effects. I think that the proper size, the proper time, and the proper number of moxibustions can be more effective than the excessive moxibustions.

Infinitely high selectivity etching of SnO2 binary mask in the new absorber material for EUVL using inductively coupled plasma

  • Lee, S.J.;Jung, C.Y.;Lee, N.E.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.285-285
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    • 2011
  • EUVL (Extreme Ultra Violet Lithography) is one of competitive lithographic technologies for sub-30nm fabrication of nano-scale Si devices that can possibly replace the conventional photolithography used to make today's microcircuits. Among the core EUVL technologies, mask fabrication is of considerable importance since the use of new reflective optics having a completely different configuration compared to those of conventional photolithography. Therefore new materials and new mask fabrication process are required for high performance EUVL mask fabrication. This study investigated the etching properties of SnO2 (Tin Oxide) as a new absorber material for EUVL binary mask. The EUVL mask structure used for etching is SnO2 (absorber layer) / Ru (capping / etch stop layer) / Mo-Si multilayer (reflective layer) / Si (substrate). Since the Ru etch stop layer should not be etched, infinitely high selectivity of SnO2 layer to Ru ESL is required. To obtain infinitely high etch selectivity and very low LER (line edge roughness) values, etch parameters of gas flow ratio, top electrode power, dc self - bias voltage (Vdc), and etch time were varied in inductively coupled Cl2/Ar plasmas. For certain process window, infinitely high etch selectivity of SnO2 to Ru ESL could be obtained by optimizing the process parameters. Etch characteristics were measured by on scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses. Detailed mechanisms for ultra-high etch selectivity will be discussed.

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Investigation on the Design Wave Forces for Ear-do Ocean Research Station II: Fluid Force in the Breaking Wave Field (이어도 종합해양과학기지에 대한 설계파력의 검토 II: 쇄파역에서의 유체력)

  • 전인식;심재설;최성진
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.12 no.4
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    • pp.168-180
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    • 2000
  • In the Part I, the three dimensional model testing with NNW deep water wave direction gave the results such that the occurrence of breaking waves over the peak of Ear-Do caused very small wave height at the structure position. But the measured wave forces were rather greater than the calculated forces based on deep water wave height. Furthermore, It was also perceived that the time series of the forces looked like corresponding to the case that waves were superimposed by an unidirectional current. In the present Part II, the current is presumed to be a flow secondly induced by breaking waves, and an extensive study to clarify the current in a quantitative sense is performed through numerical analysis and hydraulic experiment. The results showed that a strong circulation can surely occur in the vicinity of the structure due to radiation stress differentials given by the breaking waves. It was also recognized that the velocity of the induced current varied with the magnitude of energy dissipation rate introduced in the numerical analysis. The numerical analysis was tuned adjusting the dissipation rate so that the calculated wave field could closely match with the experimental results of Part I. The fluid force (in prototype) for the optimal match showed approximately 2.2% increased over the calculated value based on the deep water wave height (24.6m) whereas the force corresponding to the average of the experimental values showed the increase of about 13.0%.

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Effect of Primary Nozzle Configuration on the Flow and Transfer Characteristics in an Ejector System for Pellet Transfer (펠릿 이송용 이젝터의 구동노즐 구성에 따른 유동 및 이송특성에 관한 실험적 연구)

  • Kim, Keum-Kyu;Kim, Eui-Soo;Kang, Shin-Myoung;Lee, Jee-Keun;Rho, Byung-Joon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.5
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    • pp.49-59
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    • 2008
  • The effects of design parameters on the pellet transport rate in the ejector system which is widely used in the production processes of automotive parts were investigated experimentally. The primary nozzle geometry, the area ratio (R) of nozzle exit cross-sectional area to mixing chamber cross-sectional area and the distance (S) from primary nozzle exit to mixing chamber entrance were considered as the design parameters. The area ratios of the primary nozzle were varied from R=0.10 to R=0.25, 0.30, 0.40 and 0.55. The primary nozzle was positioned at the non-dimensional distance (S/D) of 1.30, 1.87, 2.44, 3.00 and 3.75, normalized using the mixing chamber diameter (D). The design parameters were determined to run with high efficiency by measuring the pellets transport rate. The geometry and the area ratio (R) of the primary nozzle had an effect on the pellet transport rate of the ejector system, and the area ratio of R=0.3 was carefully selected after taking the minimum fluidization velocity and transport rate of applied pellets into account. The higher pellet transport rate with the variation of the distance (S/D) was observed at S/D of 2.44.

Population Genetic Structure of Potentilla discolor Bunge, Rosaceae in Korea (한국내 솜양지꽃의 집단 유전 구조)

  • Huh, Man-Kyu
    • Journal of Life Science
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    • v.16 no.6
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    • pp.898-903
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    • 2006
  • The genetic diversity and population structure of fifteen Potentilla discolor Bunge populations in Korea were determined using genetic variations at 19 allozyme loci. Fourteen of the 19 loci (73.7%) showed detectable polymorphism. Genetic diversity at the species level and at the population level was high ($H_{ES}\;=\;0.215$, $H_{EP}\;=\;0.196$, respectively), whereas the extent of the population divergence was relatively low $(G_{ST}\;=\;0.069)$. Total genetic diversity values $(H_T)$ varied between 0.0 and 0.656, giving an average overall polymorphic loci of 0.292. The interlocus variation of genetic diversity within populations $(H_S)$ was high (0.274). On a per locus basis, the proportion of total genetic variation due to differences among populations $(G_{ST})$ ranged from 0.010 for Pgm-2 to 0.261 for Pgd-2 with a mean of 0.069, indicating that about 6.9% of the total allozyme variation was among populations. Wide geographic ranges, perennial herbaceous nature and the persistence of multiple generations are associated with the high level of genetic variation in P. discolor. The estimate of gene flow based on $G_{ST}$ was high among Korean populations of P. discolor (Nm = 3.36).

Physicochemical Characteristics of Rice Flour Gelatinized by Extrusion-Cooking (압출성형에 의한 알파미분의 물리화학적 특성)

  • Han, Ouk;Lee, Sang-Hyo;Lee, Hyun-Yu;Kim, Young-Myoung;Min, Byong-Lyoung
    • Korean Journal of Food Science and Technology
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    • v.20 no.4
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    • pp.470-475
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    • 1988
  • The extrusion-cooking method was used to make gelatinized rice extrudate from rice grits of the Chuchung and the Samgang varieties. The water contents of raw rice grits varied from 15% to 25%, and the physicochemical properties of extrudates were evaluated. Low moisture content showed high expansion ratio in rice extrudate and resulted in some decrease in gelatinization, bulk density and break strength. Increasing the water content to 25% resulted in increase in water absoption index but decrease in water solubility index. With regards to Brabender Amylograph values and rheological patterns, higher moisture content in raw materials revealed stronger pseudoplastic flow behavior with lower viscogram property. Hunter's color values of rice flours extruded at low water content were low in b values. Scanning electron microscopy demonstrated the break-down of starch granules during extrusion.

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Experimental Study on Heat Transfer Performance of CO2 in a Multi-Tube Type Gas Cooler of Inner Diameter Tube of 1.77 mm (내경 1.77 mm의 다중관식 가스냉각기내 CO2 전열 성능에 대한 실험적 연구)

  • Son, Chang-Hyo
    • Journal of Hydrogen and New Energy
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    • v.19 no.5
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    • pp.439-444
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    • 2008
  • The heat capacity and pressure drop of $CO_2$ and coolant in a multi-tube type gas cooler were investigated experimentally. The main components of the refrigerant loop are a receiver, a $CO_2$ compressor, a mass flow meter, an evaporator and a multi-tube type gas cooler as a test section. The mass flowrate of $CO_2$ and coolant were varied from 0.06 to 0.075 [kg/s], respectively and the cooling pressure of gas cooler were from 8 to 10 [MPa]. The heat capacity of $CO_2$ in the test section is increased with the increment in mass flowrate of coolant, the cooling pressure and mass flowrate of $CO_2$. The pressure drop of $CO_2$ is decreased with the decrease in mass flowrate of coolant and $CO_2$, but decreased with increase in cooling pressure of $CO_2$. The heat capacity of $CO_2$ per unit heat transfer area of gas cooler is greatly high. Therefore, in case of the application of $CO_2$ at the multi-tube type gas cooler, it is expected to carry out the high-efficiency, high-performance and compactness of gas cooler.

A PHOTOMETRIC STUDY OF THE CONTACT BINARY XZ LEONIS

  • Lee Jae-Woo;Lee Chung-Uk;Kim Chun-Hwey;Kang Young-Woon
    • Journal of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.41-50
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    • 2006
  • We present the results of new multi-color CCD photometry for the contact binary XZ Leo, together with reasonable explanations for the period and light variations. Six new times of minimum light have been determined. A period study with all available timings confirms Qian's (2001) finding that the O-C residuals have varied secularly according to $dP/dt\;=\;+8.20{\times}10^{-8}\;d\;yr^{-l}$. This trend could be interpreted as a conservative mass transfer from the less massive cool secondary to the more massive hot primary in the system with a mass flow rate of about $5.37{\times}10^{-8}\;M_{\odot}\;yr^{-l}$. By simultaneous analysis of our light curves and the previously published radial-velocity data, a consistent set of light and velocity parameters for XZ Leo is obtained. The small differences between the observed and theoretical light curves are modelled by a blue third light and by a hot spot near the neck of the primary component. Our period study does not support the tertiary light but the hot region which may be formed by gas streams from the cool secondary. The solution indicates that XZ Leo is a deep contact binary with the values of q=0.343, $i=78^{\circ}.8$, ${\Delta}(T_1-T_2)=126\;K$, and f=33.6 %, differing much from those of Niarchos et al. (1994). Absolute parameters of XZ Leo are determined as follows: $M_1=1.84\;M_{\odot},\;M_2=0.63\;M_{\odot},\;R_1=1.75\;R_{\odot},\;R_2=1.10\;R_{\odot},\;L_1=7.19\;L_{\odot},\;and\;L_2=2.66\;L_{\odot}$.

An Experimental Study on the Orifice Nozzle System that Generates Micro-bubbles by Self-suction of Air with a Recirculating Flow (재순환 유동 공기 자가흡입에 의한 마이크로버블 발생 오리피스 노즐 시스템에 대한 실험적 연구)

  • Oh, Shin-il;Park, Sang-Hee
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.1
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    • pp.82-88
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    • 2018
  • An experimental study was performed on the orifice nozzle system that generates micro-bubbles by air self-suction using a venturi nozzle. This study experimentally investigates the amount of air sucked into the venturi nozzle and the number of micro-bubbles generated by the orifice nozzle system in Cases 1 and 2. The experimental conditions were varied by changing the diameter of the orifice nozzle (d=2~7 mm) and the number of holes of the perforated plate nozzle (n = 2-12). In Case 1, the air self-suction was more than 2 LPM at $d{\leq}4mm$. When d = 4 mm, the total number of bubbles was 29,777, and it was confirmed that micro-bubbles occupied approximately 65% of the total number of bubbles. In Case 2, the air self-suction was maintained constant at approximately 2.5 LPM regardless of the number (n) of holes. The total amount of bubbles increased when n increased but remained constant at approximately 44,000 when $n{\geq}7EA$. It was also confirmed that more than 80% of all bubbles were micro-bubbles when $n{\geq}10EA$. Thus, the number of micro-bubbles increased by approximately 15% compared to the experimental result of Case 1, which was optimized with d = 4 mm.

Development of KD-Propeller Series Using a New Blade Section

  • Lee, Jin-Tae;Kim, Moon-Chan;Ahn, Jong-Woo;Kim, Ho-Chung
    • Selected Papers of The Society of Naval Architects of Korea
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    • v.1 no.1
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    • pp.76-90
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    • 1993
  • A new propeller series is developed using the newly developed blade section (KH 18 section) which has better cavitation characteristics and higher lift-drag ratio at wade angle-of-attack range than a conventional section. The radial patch distribution of the new series propellers is variable stance they were designed adaptively to a typical wake distribution. Basic geometric particulars of the series propellers. such as chord length, thickness, skew and rake distributions, are determined on the basis of recent full scale propeller geometric data. The series is developed for propellers having 4 blades, and blade area ratios of 0.3, 0.45, 0.6 and 0.75. Mean pitch ratios are varied as 0.5, 0.6, 0.7, 0.95 and 1.1 for each blade area ratio. The new propeller series consists of 20 propellers and is named as the KD(KRISO-DAEWOO)-propeller series. Propeller open-water tests are performed at the towing tank, and cavitation observation tests and fluctuating pressure tests are carried out at the cavitation tunnel of KRISO. $B_{p}-\delta$ curves, which can be used to select the optimum propeller diameter at the preliminary design stage, are derived from a regression analysis of the propeller open-water test results. The KD-cavitation chart is derived from the cavitation observation test results by choosing the local maximum lift coefficient and the local cavitation number as parameters. The cavity extent predicted by the KD-cavitation chart would be more accurate compared to that by an existing cavitation charts, such as the Burrll's cavitation chart, since the former is derived from the cavitation observation test results in a typical ship's wake, while the lather is derived from the test results in a uniform flow.

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