• Title/Summary/Keyword: intermediate region

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A multilayer Model for Dynamics of Upper and Intermediate Layer Circulation of the East Sea (동해의 상, 중층 순환 역학에 대한 다층모델)

  • 승영호;김국진
    • 한국해양학회지
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    • v.30 no.3
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    • pp.227-236
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    • 1995
  • A simple layer model based on isophcnal coordinate is applied to the East Sea to examine the dynamics of circulation. The results confirm the existing knowledge about role of inflow-outflow and wind in driving the circulation. It is found, however, that the buoyancy flux generates quite different circulation pattern; it enhances the inflow-outflow driven circulation and has a convective nature. The circulation considering all these effects resembles the schematic one presently known. In the circulation, the intermediate layer is outcropped in the north off the northern boundary, ventilated here and flows cyclonically in the northern part of basin. This water, however, does not flow southward directly because of the strong eastward (separating from the coast) current in the layer above. This water also loses its potential vorticity while traveling around the periphery of the outcropping region and is thus characterized by minimum potential vorticity in the interior of the basin.

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Preliminary Investigation on Joining Performance of Intermediate Heat Exchanger Candidate Materials of Very High Temperature Reactor(VHTR) by Vacuum Brazing (진공 브레이징을 이용한 고온가스냉각로 중간 열교환기 후보재료의 접합성능에 관한 예비시험)

  • Kim, Gyeong-Ho;Kim, Gwang-Ho;Lee, Min-Gu;Kim, Heung-Hoe;Kim, Seong-Uk;Kim, Suk-Hwan
    • Proceedings of the KWS Conference
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    • 2005.11a
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    • pp.195-197
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    • 2005
  • An intermediate heat exchanger(IHX) is a key component in a next-generation VHTR with process heat applications such as hydrogen production and also for an indirect gas turbine system. Therefore, high temperature brazing with nickel-based filler metal(MBF-15) was carried out to study the joining characteristic(microstucture, joining strength) of nickel-based superalloy(Haynes 230) by vacuum brazing. The experimental brazing was carried out at the brazing process, an applied pressure of about 0.74Mpa and the three kinds of brazing temperatures were 1100, 1150, and $1190^{\circ}C$ with holding time 5 minute. It's joining phenomena were analyzed by optical microscopy and scanning electron microscopy with EPMA. The results of microstructure in the centre-line region of a joint brazed with MBF-15 show a typical ternary eutectic of v-nickel, nickel boride and chromium boride.

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Proton Conductivity of Niobium Phosphate Glass Thin Films

  • Kim, Dae Ho;Park, Sung Bum;Park, Yong-il
    • Korean Journal of Materials Research
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    • v.28 no.5
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    • pp.308-314
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    • 2018
  • Among the fuel cell electrolyte candidates in the intermediate temperature range, glass materials show stable physical properties and are also expected to have higher ion conductivity than crystalline materials. In particular, phosphate glass has a high mobility of protons since such a structure maintains a hydrogen bond network that leads to high proton conductivity. Recently, defects like volatilization of phosphorus and destruction of the bonding structure have remarkably improved with introduction of cations, such as Zr4+ and Nb5+, into phosphate. In particular, niobium has proton conductivity on the surface because of higher surface acidity. It can also retain phosphorus content during heat treatment and improve chemical stability by bonding with phosphorus. In this study, we fabricate niobium phosphate glass thin films through sol-gel processing, and we report the chemical stability and electrical properties. The existence of the hydroxyl group in the phosphate is confirmed and found to be preserved at the intermediate temperature region of $150-450^{\circ}C$.

Flow Mechanism around Air Flow Sensor of Electronic Control Engine (전자제어 엔진의 공기유량센서 유동구조 연구)

  • 이종춘;황성만;부정숙
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.4
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    • pp.486-493
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    • 2000
  • Flow mechanism around air flow sensor of electronic control engine, especially Karman vortex type, was investigated experimentally. The two-dimensional flow characteristics in the intermediate wake region behind a triangular vortex-generator respectively apex forward facing, apex backward facing and vertical flat plates following after apex forward facing(i.e vortex-flowmeter) were investigated at Reynolods number of $ReH=1.4\times10^4$; H is the width of a triangular vortex-generator. The vortex shedding frequency for wide Reynolds number from $7\times10^3$ to $2.1\times10^4$ was also surveyed. The velocity component was measured by X-type hot wire anemometer at 8H downstream from the bluff body. The coherent structure of the intermediate wake behind a bluff body was obtained by conditional phase average technique. As a result, it was verified that the vertical flat plates following after apex forward triangular vortex-generator make not only more linear relation between free stream velocity and vortex shedding frequency but also more periodic vortex in the vicinity of the center of wake.

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Spectroscopic Studies on Crystallization of Na, TPA-ZSM-5 synthesized at Low Temperature and Atomospheric pressure (저온 상압에서 합성된 Na, TPA-ZSM-5의 결정화에 관한 분광학적 고찰)

  • Yun, Young Ja;Ha, Jae Mok
    • Analytical Science and Technology
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    • v.10 no.1
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    • pp.18-30
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    • 1997
  • Na, TPA-ZSM-5 with Si / Al mole ratio of about 130 was synthesized at low temperature and atmospheric pressure. These intermediate products were characterized by using XRD, XRF, FT-IR, NMR, and SEM. As a result, intermediate product were different from those that synthesized by autoclave method but spectroscopic characteristics of the final products showed to be in the typical ZSM-5 region. The defect sites were observed in the final product and removed by calcination at $540^{\circ}C$. Na, TPA-ZSM-5, aboveall, was synthesized at this condition within 48hr.

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Seismic Behavior of Columns in Ordinary and Intermediate Moment Frames (보통과 중간 모멘트 골조 기둥의 내진거동 비교)

  • Han Sailg-Whan
    • Journal of the Korea Concrete Institute
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    • v.17 no.1 s.85
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    • pp.51-58
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    • 2005
  • Moment frames have been widely used in building construction. In current design codes, concrete moment frames are classified into ordinary, intermediate, and special moment resisting concrete frames (OMRCF, IMRCF, SMRCF)). The objective of this study is to investigate the seismic behavior of columns in ordinary moment resisting concrete frames (OMRCF) and intermediate moment resisting concrete frames (IMRCF). For this purpose 3 story OMRCF and IMRCF buildings were designed and detailed in compliance to ACI 318 (2002) and KCI (1999). In this study the buildings were assumed to be located in seismic zone 1 classified by UBC (1997). This study considered the columns in the 1st story since these columns shall resist the largest axial and lateral forces during an earthquake. Eight 2/3 scale column specimens were made for representing the upper part and lower part of exterior and interior columns of the OMRCF and the IMRCF Quasi-static reversed cyclic loading was applied to each specimen with a constant or varying axial load. Test results show that seismic behaviors of columns are influenced by existence of lap splices, axial force levels, and lateral reinforcement at possible plastic hinging region. However, the effect of such variables strongly co-related to each other.

A re-route method for reliable data transport in Ad Hoc Networks (Ad Hoc 망에서 신뢰성 있는 데이터 전송을 위한 경로 재설정 기법)

  • 한정안;백종근;김병기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.3A
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    • pp.276-287
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    • 2004
  • An ad hoc network is infra(Base Sstation or Access Point) free wireless mobile communication technology. Mobile nodes function as routers and servers in ad hoc networks. Many routing protocols for ad hoc network have been proposed. If any route is broken owing to moving node, source must repair broken route again. But route repair technology after route collapses is not suitable to transmit real-time data packet for QoS guarantee. So this paper presents route repair technology that prevents route from breaking. If intermediate node moves to critical section, the node issues handoff packet and sends the packet to the next node. After next node receives handoff packet, the node broadcasts route request packet to the previous node for intermediate node. Finally, even if intermediate node moves out of the routing region, the source can continuously transmit data packets to the destination through the new path.

Intermediate Scene Interpolation using Bidirectional Disparity (양방향 시차 몰핑을 이용한 중간 시점 영상 보간)

  • Kim, Dae-Hyeon;Yun, Yong-In;Choe, Jong-Su;Kim, Je-U;Choe, Byeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.2
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    • pp.107-115
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    • 2002
  • In this paper, we describe a novel method to generate an intermediate scene using BDM (Bidirectional Disparity Morphing) from the parallel stereopair. Because an image is composed of several layers and each layer has a similar disparity, it is available to use the block based disparity estimation. In order to prevent the false correspondence, however, we closely investigate the corresponding block as we adaptively vary the block size according to the estimation error. Therefore, we can detect the occlusion because of larger estimation error of the occluded region. We define three occluding patterns, which ate derived from the peculiar property of the disparity map, in order to smooth the computed disparity map. The filtered disparity map using these patterns presents that the false disparities ate well corrected and the boundary between foreground and background becomes sharper. As a result, we can improve the quality of the intermediate scenes.

Fishborne Trematode Metacercariae in Freshwater Fish from Guangxi Zhuang Autonomous Region, China

  • Sohn, Woon-Mok;Eom, Keeseon S.;Min, Duk-Young;Rim, Han-Jong;Hoang, Eui-Hyug;Yang, Yichao;Li, Xueming
    • Parasites, Hosts and Diseases
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    • v.47 no.3
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    • pp.249-257
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    • 2009
  • A survey was performed to investigate the infection status of fishborne trematode (FBT) metacercariae in freshwater fish from Guangxi Zhuang Autonomous Region, China. A total of 307 freshwater fish of 31 species were collected from 5 administrative regions of Guangxi Zhuang Autonomous Region. They were examined by artificial digestion method from July 2003 to August 2004. No metacercariae were detected in fish from Fusui-xian. In fish from Mashan-xian and a market in Nanning, 3 species of metacercariae, Haplorchis taichui, Haplorchis pumilio, and Centrocestus formosanus, were mainly detected. Metacercariae (8 in number) of Clonorchis sinensis were found in 1 Chanodichthys dabryi purchased from a market in Nanning. In fish from Yangshuo, Metagonimus yokogawai metacercariae were detected from all 18 fish species examined. Total 13 C. sinensis metacercariae were found in 3 out of 10 Hemibarbus maculatus from Yangshuo. All7 Zacco platypus from Yangshuo were infected with 8-112 Echinochasmus perfoliatus metacercariae. In fish from Binyang-xian, H. pumilo metacercariae were mainly detected in all 5 fish species examined, and only 1 metacercaria of C. sinensis was found in a Hemiculter leucisculus. From the above results, it was confirmed that some species of freshwater fish play a role of second intermediate hosts for FBT in Guangxi Zhuang Autonomous Region, China. In particular, 4 species of intestinal flukes, M. yokogawai, H. taichui, H. pumilio, and C. formosanus, were prevalent in fish hosts, whereas C.sinensis metacercariae were detected only in 3 fish species.

Comparison of salty taste acuity and salty taste preference with sodium intake and blood pressure based on zinc nutritional status in two rural populations in Korea

  • Choe, Jeong-Sook;Kim, Eun-Kyung;Kim, Eun-Kyung
    • Nutrition Research and Practice
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    • v.6 no.6
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    • pp.534-541
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    • 2012
  • This study examined salty taste acuity and salty taste preference and sodium intake in relation to zinc nutritional status in 2 rural populations in Korea. And we also examined the main food contributors of their sodium intakes. We enrolled 218 adults (66 men and 152 women) from the Kangneung and Samcheok regions in Korea's Kangwon province in our study conducted from December 2011 to February 2012. Participants from each region were divided into 3 groups based on their serum zinc level (T1: lowest, T2: intermediate, T3: highest). We compared the salty taste acuity and preference, Na index (Dish Frequency Questionnaire for estimation of habitual sodium intake), blood pressure, and intakes of nutrients including sodium by 3 groups of serum zinc level. The results were as follows: a higher serum zinc level indicated a lower sodium intake and Na index (P<0.05). The salty taste acuity was considerably higher for participants from the Kangneung region than those from the Samcheok region (P<0.05). And the serum zinc level was significantly higher in participants from the Kangneung region than those from the Samcheok region (P<0.05). We further divided the participants into 2 groups: those who consumed more zinc than the recommended intake (RI) and the others. We compared salty taste acuity and salty taste preference in the 2 groups. The salty taste threshold and palatable salty taste concentrations were lower for the group with a zinc intake above RI than for the group with zinc intake below the RI. However, the difference was not significant. This study confirms that taste function differs depending on zinc nutritional status. In future, it is required to a large-scale, long-term, prospective study on the correlation between zinc intake, serum zinc levels, and taste perception function and blood pressure.