• Title/Summary/Keyword: 유동장

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Breeding of A New Saxifraga fortune Cultivar (Hybrid) 'Crystal' with Light Pink on a White Green Ground Colored Petals for Pot Flower (연한 녹색 바탕에 밝은 핑크색 꽃의 분화용 바위떡풀 신품종 '크리스탈' 육성)

  • Suh, Jong-Taek;Hong, Su-Young;Yoo, Dong-Lim;Nam, Chun-Woo;Ryu, Seung-Yeol;Lee, Eung-Ho
    • Horticultural Science & Technology
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    • v.30 no.2
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    • pp.224-228
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    • 2012
  • A new $Saxifraga$ $fortunei$ cultivar 'Crystal' was bred by crossing 'Dotaerang' with light pink and light Green (RP 58D) colored petals and 'Rocksun' with light pink and light green white (RP62A + GW157A) colored petals. The selection and flower characterization were conducted from 2004 to 2007 in a greenhouse of the National Institute of Highland Agriculture. The flowering of 'Crystal' occurred from September 21 for 31 days. The number of flowers per plant was 279.0 with many flowering habit. The flower coloration was mixed light pink and green white (RP62D + GW157B) at the opening. The number of petals were 7.0, with a width of 2.1 cm and length of 1.8 cm. The plant height was 15.3 cm and number of leaves was 133.7. 'Crystal' cultivar can be used for pot flower. Fifty percent shading is a good cultural practice against direct sunlight and soft rot disease would occurs usually by over-irrigation. 'Crystal' cultivar was registered as a new variety with No. 3466 at Korea Seed and Variety Service in April of 2011 year.

Breeding of Asiatic Hybrid Lily 'Redsky' with Orange Red Color Petals for Cut Flowers (절화용 주황색 아시아틱나리 '레드스카이' 품종 육성)

  • Suh, Jong-Taek;Yoo, Dong-Lim;Nam, Chun-Woo;Kim, Su-Jeong;Hong, Soo-Young;Ryu, Seung-Yeol
    • Horticultural Science & Technology
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    • v.30 no.3
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    • pp.329-333
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    • 2012
  • A new Asiatic hybrid lily 'Redsky' cultivar was selected from a cross between 'Vivaldi' cultivar with pale pink color flower as mother plant and 'Prato' with orange colored flower in 2000 year. The selected bulb line was propagated and cultivated for line nomenclature as 'Gonong-F-na-10'. The survey of the growth and flower characteristics of 'Gonong-F-na-10' were conducted from 2005 to 2007 on summer cropping system under structure in Highland Agriculture Research Center, NICS, RDA. After all 'Gonong-F-na-10' was named as 'Redsky'. The flowers of the 'Redsky' cultivar had not soft hair and fragrance, and had orange red (O-R N30D) colored petals with dark brown spots in center of flower. The stem color was dark pink and brown caused by anthocyanin pigment, the stigma and pollen colors were brown. Flowering direction was upward. The flowering date was July 7 so early flowering. The plant height was 97.2 cm so long, number of flowers was 4.9 ea, and length of flower bud was 9.3 cm. The bulb weight was about 34.8 g and its bulb size was about 14.8 cm in circumference. 'Redsky' cultivar was registered as a new variety with No. 3119 in Korea Seed and Variety Service on June of 2010.

Improved Transmission Path Visualization of Vibration Power Flow for Stiffened Plate Using Streamlines Representation (유선 표현법을 이용한 보강판의 진동파워흐름에 대한 개선된 전달경로 가시화)

  • Fawazi, Noor;Jeong, Un-Chang;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.7
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    • pp.692-700
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    • 2012
  • Vibration intensity has been used to localize vibration source of a vibrating system. Not only that, vibration intensity has also been used for structural diagnostic in identifying crack and mounted stiffeners. To clearly identify the location of vibration source and understand the changes of energy transmission path, clear flow visualization is required. Most of previous works used vectors to indicate the magnitude and direction of emerging vibration energy and transmission paths. However, due to the large surface area of a plate like-structure, clear transmission paths cannot be achieved using vector visualization. This becomes an issue when detail vector flow at all locations of the whole plate surface is required. In this study, streamlines visualization is used to clearly indicate the power flow transmission path at all plate surface. By using streamlines representation, not only clear transmission paths are obtained, but also improves the vector visualization which helps us to understand the changes of the energy flow especially for stiffened plates. In this study, vibration intensity computation is firstly compared to previous work to validate the vibration intensity computation. To clearly show the power flow transmission paths, streamlines representation is shown. This representation overcomes the unclear vector direction especially for stiffened plates. Different pattern of energy transmission path can be observed using streamlines representation for stiffened and unstiffened plate. The complex streamlines pattern can also be observed at high resonance frequencies which is unclear by using vector representation.

Effect of AC Electric Fields on Flow Instability in Laminar Jets (층류제트유동 불안정성에 미치는 교류 전기장 효과)

  • Kim, Gyeong Taek;Lee, Won June;Cha, Min Suk;Park, Jeong;Chung, Suk Ho;Kwon, Oh Boong;Kim, Min Kuk;Lee, Sang Min
    • Journal of the Korean Society of Combustion
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    • v.21 no.3
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    • pp.1-6
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    • 2016
  • The effect of applied electric fields on jet flow instability was investigated experimentally by varying the direct current (DC) voltage and the alternating current (AC) frequency and voltage applied to a jet nozzle. We aimed to elucidate the origin of the occurrence of twin-lifted jet flames in laminar jet flow configuration, which occur when AC electric fields are applied. The results indicate that a twin-lifted jet flames originates from cold jet instability, caused by interactions between negative ions in the jet flow via electron attachment as $O_2+e{\rightarrow}O_2{^-}$ when AC electric fields are applied. This was confirmed by experiments in which a variety of gaseous jets were ejected from a nozzle to which DC voltages and AC frequencies and voltages were applied, with ambient air between two deflection plates connected to a DC power source. Experiments in which jet flows of several gases were ejected from a nozzle and AC electric fields were applied in coflow-nitrogen provided further evidence. The flow instability occurred only for oxygen and air jets. Additionally, jet instability occurred when the applied frequency was less than 80 Hz, corresponding to the characteristic collision response time. The effect of AC electric fields on the overall structure of the jet flows is also reported. Based on these results, we propose a mechanism to reduce jet flow instability when AC electric fields are applied to the nozzle.

Rheological Properties of Rehydrated Suspensions of Freeze Dried Kochujang Powders (동결건조 분말고추장의 재수화시 리올로지 특성)

  • Kim, Suk-Shin;Chang, Kyu-Seob;Yoon, Han-Kyo;Lee, Sang-Kyu;Lee, Shin-Young
    • Korean Journal of Food Science and Technology
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    • v.19 no.2
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    • pp.81-88
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    • 1987
  • Rheological properties of rehydrated suspensions of two kinds of freeze dried Kochujang powders, processed at different freezing rates, were compared with raw Kochujang using Brookfield wide-gap rotational viscometer at $25^{\circ}C-60^{\circ}C$. Shear rates ranged from $0.1965\;sec^{-1}$ to $1.9650\;sec^{-1}$ and solid content ranged from 47% to 56%. Rehydrated suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang exhibited pseudoplastic behaviors with yield stress and presented thixotropic properties which followed the second-order kinetic behavior proposed by Tiu. Suspensions of Kochujang powders exhibited considerably higher decaying rates than raw Kochujang. The dependency of the equilibrium structure parameter on the shear rate was weak, and there were no significant differences among the values of structure parameters of three samples. The temperature dependency of the apparent viscosity of Kochujang suspension was fully expressed by Arrhenius equation and activation energies of suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang were 2.21, 2.18, and 2.32 Kcal/g.mole respectively. Consistency indices of three samples increased with solid content and decreased with temperature. Flow behavior indices of three samples showed no considerable dependency on the temperature and solid content. There were no significant differences in the rheological properties between two Kochujang powders.

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A Study on Numerical Analysis of Selective Withdrawal from Reservoir (저수지 선택취수에 관한 수치해석 연구)

  • Kim, Young-Do;Kim, Tae-Won;Yi, Yong-Kon;Kim, Woo-Gu
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.1302-1306
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    • 2007
  • 여름철의 강우시 저수지에 주로 유입되는 고탁수층은 저수지내의 수체에 대하여 밀도차와 유속차를 가지며, 난류혼합을 일으키면서 주변수를 유입하며 하류방향으로 이송 확산되어 간다. 임하댐과 같은 대형 저수지는 수심이 30 m가 넘는 관계로 여름철에 2개의 수온약층이 존재한다. 따라서 댐체에 도달한 고탁수층은 저수지내의 밀도성층으로 인하여 주로 중층에 분포하게 되며, 가을철에 발생하는 수평확산과 전도현상으로 인해 저수지 전역에 분포하게 되어 탁질입자의 분포에 따라 탁수현상의 장기화를 유발하기도 한다. 이와 같은 탁수문제의 저수지내 대책으로는 홍수기에 고탁수층을 우선적으로 취수하는 방법이 있다. 고탁수층은 이와같이 수온약층과 밀접한 관계를 가지며, 취수탑 주변의 선택취수 결과에 영향을 받는다. 형성된 탁수층을 효율적으로 선택배제하기 위해서는 취수시설에 접근하는 성층흐름을 정확하게 이해해야 한다. 본 연구에서는 3차원 CFD를 사용하여 밀도성층에 따른 취수탑 주변의 접근흐름을 수치해석하여 방류수심, 방류유속 및 밀도성층구조의 선택배제에 대한 영향을 분석하였다. 임하댐 취수설비에 적용한 결과에 의하면 상층, 중층, 하층에서 취수탑 문비를 개도하였을 경우, 취수탑 주변에서만 유속이 증가하였을 뿐 저수지 내에서는 유속이 크게 증가되지 않은 것으로 나타났다. 하지만 문비 개도구간의 변화에 따라 수심별 유속분포는 크게 변화하는 것을 확인할 수 있다. 따라서 문비를 조절하는 것은 저수지 전체의 유동을 깨뜨리지 않으면서 취수탑 인근에서 선택취수가 가능하다는 것을 확인할 수 있었다. 또한 본 연구에서는 정밀한 현장조사를 수행하여 저수지와 방류수의 탁도변화를 모니터링하였으며, 취수탑 개구부 주변의 연직 유속분포를 측정하였다. 3차원 수치모의 결과와 현장에서 관측한 유속장을 비교함으로써 본 연구에서 제시한 실제 탁수배제능력을 검증하였다.를 구축하였다는데 의의가 있다.로와 접하는 건물의 경우 모서리부 광고 효과가 지배적이며 대부분 곡선돌출형이 사용되고 있었다. 그러므로 모서리 저층부를 필로티로 계획하여 보행흐름을 원활하게 하고 대신 입면을 투명하게 하여 간접광고(내부전시) 효과를 유도하는 것이 좋다. 특히 원형모서리는 건물 특화 성격이 강하므로 불가피할 경우 소형 액센트 광고 위치를 미리 벽면으로 할애하는 것이 경관 및 입면계획에 유리한 것으로 분석되었다. 불확실도 해석모형 등의 새로운 기능을 추가하여 제시하였다. 모든 입출력자료는 프로젝트 단위별로 운영되어 data의 관리가 손쉽도록 하였으며 결과를 DB에 저장하여 다른 모형에서도 적용할 수 있도록 하였다. 그리고 HyGIS-HMS 및 HyGIS-RAS 모형에서 강우-유출-하도 수리해석-범람해석 등이 일괄되게 하나의 시스템 내에서 구현될 수 있도록 하였다. 따라서 HyGIS와 통합된 수리, 수문모형은 국내 하천 및 유역에 적합한 시스템으로서 향후 HydroInformatics 구현을 염두에 둔 특화된 국내 수자원 분야 소프트웨어의 개발에 기본 토대를 제공할 것으로 판단된다.았다. 또한 저자들의 임상병리학적 연구결과가 다른 문헌에서 보고된 소아 신증후군의 연구결과와 큰 차이를 보이지 않음을 알 수 있었다. 자극에 차이가 있지 않나 추측되며 이에 관한 추후 연구가 요망된다. 총대장통과시간의 단축은 결장 분절 모두에서 줄어들어 나타났으나 좌측결장 통과시간의 감소 및 이로 인한 이 부위의 통과시간 비율의 저하가 가장 주요하였다. 이러한 결과는 차가운 생수 섭취가 주로 결장 근위부를 자극하는 효과를 발휘하는 것이 아닌가 해석된다. 이와 같은 연구결과를 통해 생다시마를 주원료로 개발된 생다시마차와 생다시마 음료가 만성 기능성 변비 증세를 개선하는 효능이 잠재적으로 있음을 확인하였다. 그러나 생약제재의 변비약 수준으로

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Synthesis of Hectorite by Hydrothemal Method (저온 수열법에 의한 헥토라이트 합성)

  • Jang, Young-Nam;Chae, Soo-Chun;Ryu, Gyoung-Won;Kim, You-Dong;Jang, Hee-Dong;Bae, In-Kook
    • Journal of the Mineralogical Society of Korea
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    • v.20 no.1 s.51
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    • pp.1-6
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    • 2007
  • Hectorite was synthesized by a two-step hydrothermal process from $Mg(OH)_{2}$, water glass (${\sim}30\;wt%\;SiO_{2}$) and Li-compound at $90{\pm}5^{\circ}C$. The product shows excellent dispersion and swelling properties. The mixture of the starting materials was heated in a glass vessel for the first reaction with continuous stirring and the pH of the solution was adjusted to $6{\sim}8$, resulting in the formation of a precursor of hectorite. The excess salt components were washed out from the resulting slurry and then was matured in the glass vessel for the 2nd reaction. Li compound was added during the reaction. After a 10 h retention, the gel of hectorite was formed. The XRD pattern of the synthesized one was coincided with that of natural hectorite and SEM study revealed uniform grains 50 m in diameter. The d001 basal spacing of the product moved from 12 to $17.4\;{\AA}$ after glycolation treatment. The measured value of CEC and the swelling capacity was 90 cmol/kg and $60{\sim}70\;mL/2\;g$, respectively.

Food-Networks and Border-Crossing of Transnational Marriage Migrant Households (초국적 결혼이주가정의 음식: 네트워크와 경계 넘기)

  • Choi, Byung-Doo
    • Journal of the Korean association of regional geographers
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    • v.23 no.1
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    • pp.1-22
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    • 2017
  • This paper is to consider conceptually a formation of food-networks and border-crossing of transnational marriage migrant households on the basis of actor-network theory, and to analyze empirical data on the issues collected by interview with marriage migrant women living around Daegu, S.Korea. Some research results can be argued as follows: First, food can be seen, not as a single material object, but as a multiple and hybrid network of human and nonhuman (material and institutional) actors, in which activities of food cooking and eating are regulated by and (re)construct social relations and placeness of households. Secondly, food-networks in marriage migrant households implement relationships of micro-power (and attachment) in the process of its (re)formation, and hence the food-network, it can be argued, is a field of power in which conflicts and compromising around food cooking and eating are intersecting each others. Thirdly, food-networks in marriage migrant households in both their origin country and in the Korean home are not only affected by macro natural and social environments but also by micro placeness of the households, both of which constitute the food-networks and operate in relations with other actors in the netwroks. Finally, food-networks in marriage migrant households reflect multiple and multi-scalar spatial mobility and placeness of transnational food culture, through which they express topologically 'fluid space' and 'absent presence', in which marriage migrant women can (or cannot) conduct social and cultural border-crossing.

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Measurements of Streambed Hydraulic Conductivity Using Drive-point Piezometers and Seepage Meters in the Upper Reaches of Anseong Stream (관입형 피조미터와 시피지미터를 이용한 안성천 상류구간 하상 수리전도도 측정)

  • Lee, Jeongwoo;Chun, Seon Geum;Yi, Myeong Jae;Kim, Nam Won;Chung, Il-Moon;Lee, Min Ho
    • The Journal of Engineering Geology
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    • v.25 no.3
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    • pp.413-420
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    • 2015
  • Streambed hydraulic conductivity along the upper reaches of the Gongdo stage of Anseong Stream was estimated through measurements of stream-aquifer exchange rates (using a seepage meter) and vertical hydraulic gradients (using a manually driven piezometer). From the measured data, it was found out that the stream-aquifer exchange rates varied from -1.55 × 10-6 to 1.77 × 10-5 m/s, the corresponding vertical hydraulic gradient varied from -0.122 to 0.030, and the values of the streambed vertical hydraulic conductivity were estimated from 1.77 × 10-5 to 1.97 × 10-3 m/s, with variations representing local differences. The results are within the general range of streambed hydraulic conductivity values suggested by Calver (2001) and are slightly higher than values previously measured at other stream sites in Korea. The combined use of a drive-point piezometer and seepage meter (both constructed of high-strength stainless steel) is expected to be of practical use in the estimation of streambed hydraulic conductance, given the durability and portability of the instruments.

Characteristics of the New Ever-bearing Strawberry 'Yeolha' for High Yield (다수성 사계성 딸기 '열하' 육성)

  • Lee, Jong Nam;Kim, Hye Jin;Kim, Ki Deog;Yoo, Dong Lim;Suh, Jong Taek
    • Horticultural Science & Technology
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    • v.32 no.5
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    • pp.739-743
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    • 2014
  • This work characterizes 'Yeolha', a new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar that was released by the Highland Agriculture Research Center, RDA, in 2013. This cultivar originated from a 2008 cross between 'Goha' and 'Elsinyo' and showed excellent ever-bearing characteristics including continuous a flowering habit under long-day and high temperature conditions. It was originally named 'Saebong No. 5' after examining its characteristics and productivity in summer culture from 2010 to 2013. After two regional adaptability tests in 2012, it was selected as an elite cultivar and renamed 'Yeolha'. The general characteristics of 'Yeolha' include a semi-spreading plant type, elliptic leaves, and strong vigor in growth. Its fruit is conical and red. T he s oluble s olids content of 'Yeolha' is 8 .6%, w hich is 0.6% h ig her than t hat of 'Flamenco', b ut f ruit hardness is lower than that of 'Flamenco'. The average fruit weight of 'Yeolha' is about 12.1 g and the marketable yield is $28,133kg{\cdot}ha^{-1}$, which is 117% higher than that of 'Flamenco'. 'Yeolha' is resistant against Fusarium wilt. In addition, 'Yeolha' is suitable for four-season cultivation as a high harvesting cultivar because it shows continuous flowering under long-day and high temperature conditions.