• Title/Summary/Keyword: formation temperature

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Preconditioning Phase for Open Ocean Formation in the Northern Part of Subpolar Front of the East Sea (외양대류에 의한 동해 심층수의 형성 가능성)

  • Lee Chung Il;Cho Kyu Dae;Kim San-Woo;Yun Jong-Hwui;Park Sung-Eun
    • Proceedings of KOSOMES biannual meeting
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    • 2004.11a
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    • pp.117-122
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    • 2004
  • In order to investigate the initial stage of deep water formation between Vladivostok and the subpolar front in the East Sea, the factors, temperature, salinity, dissolved oxygen, measured by multi-ship surveys in 1969 have been used Deep water formation in the East Sea occurs in essentially two different forms: near continent and open ocean formation the position of eddy derived from potential vorticity matches well with that of deep water formation. The vertical and horizontal distributions of potential vorticity, geostrophic current, temperature, salinity and dissolved oxygen give clues for the preconditioning phase of open ocean formation like a doming of isotherm, associated with a cyclonic circulation

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Preconditioning phase for open ocean formation in the northern part of subpolar front of the East Sea (동해에서 외양대류에 의한 심층수 형성 초기단계의 특성)

  • Lee, Chung-Il;Kim, Dong-Sun;Kim, Sang-Woo;Yun, Jong-Hwui
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.11 no.1 s.22
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    • pp.77-82
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    • 2005
  • In order to investigate the initial stage of deep water formation between Vladivostok and the subpolar front in the East Sea, the factors, temperature, salinity, dissolved oxygen, measured by multi-ship surveys in ]969 have been used. Deep water formation in the .cast Sea occurs in essentially two different forms: near continent and open ocean formation. The position of eddy derived from potential vorticity matches well with that of deep water formation. The vertical and horizontal distributions of potential vorticity, geostrophic current, temperature, salinity and dissolved oxygen give clues for the preconditioning phase qf open ocean formation like a doming of isotherm, associated with a cyclonic circulation.

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Optimization of Sawdust Media Composition and Culture Conditions for the Mycelial Growth and Primordia Formation of Agrocybe cylindracea (버들송이(Agrocybe cylindracea)의 균사생장 및 원기형성을 위한 톱밥 배지조성(培地組成) 및 배양조건(培養條件)의 최적화(最適化))

  • Park, Shin;Lee, Jae-Sung
    • The Korean Journal of Mycology
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    • v.18 no.4
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    • pp.198-202
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    • 1990
  • Some factors effecting on the mycelial growth and primordia formation of Agrocybe cylindracea were investigated. Among supplements added into sawdust, wheat bran was the best for the mycelial growth, and its appropriate concentration was 30%. A variety of sawdust preparations was tested singly and in combinations. Oak sawdust and the combination of oak and larch sawdust were the most effective for the mycelial growth. The optimal moisture content was 65%, and the range of optimal temperature was $25\:{\sim}\:28^{\circ}C$. The favorable conditions for the primordia formation appeared to be similar to those of the mycelial growth. Among supplements added into sawdust, wheat bran 30% and the combination of wheat bran and rice bran 30% were the best for the primordia formation. Oak sawdust, and the oak plus larch sawdust and oak plus poplar sawdust were the best for the primordia formation. The optimal temperature for the primordia formation was $17{\pm}2^{\circ}C$.

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Calculation of Fuel Spray Impingement and Fuel Film Formation in an HSDI Diesel Engine

  • Kyoungdoug Min;Kim, Manshik
    • Journal of Mechanical Science and Technology
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    • v.16 no.3
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    • pp.376-385
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    • 2002
  • Spray impingement and fuel film formation models with cavitation have been developed and incorporated into the computational fluid dynamics code, STAR-CD. The spray/wall interaction process was modeled by considering the effects of surface temperature conditions and fuel film formation. The behavior of fuel droplets after impingement was divided into rebound, spread and splash using the Weber number and parameter K(equation omitted). The spray impingement model accounts for mass conservation, energy conservation, and heat transfer to the impinging droplets. The fuel film formation model was developed by integrating the continuity, momentum, and energy equations along the direction of fuel film thickness. Zero dimensional cavitation model was adopted in order to consider the cavitation phenomena and to give reasonable initial conditions for spray injection. Numerical simulations of spray tip penetration, spray impingement patterns, and the mass of film-state fuel matched well with the experimental data. The spray impingement and fuel film formation models have been applied to study spray/wall impingement in high-speed direct injection diesel engines.

Analysis of Keyhole Formation and Stability in Laser Spot Welding (레이저 점 용접의 키홀 발생과 안정성에 대한 해석)

  • 고성훈;이재영;유중돈
    • Journal of Welding and Joining
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    • v.20 no.4
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    • pp.484-490
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    • 2002
  • The formation and stability of stationary laser weld keyholes were investigated using a numerical simulation. The effect of multiple reflections in the keyhole was estimated using the ray tracing method, and the free surface profile, flow velocity and temperature distribution were calculated numerically. In the simulation, the keyhole was formed by the displacement of the melt induced by evaporation recoil pressure, while surface tension and hydrostatic pressure opposed cavity formation. A transition mode having the geometry of the conduction mode with keyhole formation occurred between the conduction and keyhole modes. At laser powers of 500W and greater, the protrusion occurred on the keyhole wall, which resulted in keyhole collapse and void formation at the bottom. Initiation of the protrusion was caused mainly by collision of upward and downward flows due to the pressure components, and Marangoni flow had minor effects on the flow patterns and keyhole stability.bility.

Simulation of Spray Impingement and Fuel Film Formation in a Direct Injection Diesel Engine (직접분사식 디젤엔진에서의 분무충돌과 연료액막형성 해석)

  • Kim, Man-Shik;Min, Kyoung-Doug;Kang, Bo-Seon
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.919-924
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    • 2000
  • Spray impingement model and fuel film formation model were developed and incorporated into the computational fluid dynamics code, STAR-CD. The spray/wall interaction process were modelled by considering the change of behaviour with surface temperature condition and fuel film formation. We divided behaviour of fuel droplets after impingement into stick, rebound and splash using Weber number and parameter K. Spray impingement model accounts for mass conservation, energy conservation and heat transfer to the impinging droplets. A fuel film formation model was developed by Integrating the continuity, the Navier-Stokes and the energy equations along the direction of fuel film thickness. The validation of the model was conducted using diesel spray experimental data and gasoline spray impingement experiment. In all cases, the prediction compared reasonably well with experimental results. Spray impingement model and fuel film formation model have been applied to a direct injection diesel engine combustion chamber.

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Factors Affecting Appressorium Formation in the Rice Blast Fungus Magnaporthe grisea (벼 도열병균의 부차기 형성에 미치는 요인 분석)

  • 이승철;강신호;이용환
    • Korean Journal Plant Pathology
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    • v.14 no.5
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    • pp.413-417
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    • 1998
  • Magnaporthe grisea, the casual agent of rice blast, requires formation of an appressorium, a dome-shaped and well melanized infection structure, to penetrate its host. Environmental cues that induce appressorium formation include hydrophobicity and hardness of contact surface and chemicals from its host. Artificial surfaces are widely used to induce appressorium formation, but frequencies of appressorium induction are not always consistent. To understand variable induction of appressorium formation in M. grisea, several factors were tested on GelBond. High levels of appressorium formation were induced over a wide range of temperature (20~3$0^{\circ}C$) and pH (4~7). spore age up to 3-week-old did not significantly affect appressorium formation, but only a few apressoria on GelBond. However, adenosine specifically inhibited appressorium formation. Adenosine inhibition of appressorium formation was restored by exogenous addition of cAMP. Germ tube tips of M. grisea maintained the ability to differentiate appressoria by chemical inducers on GelBond at least up to 16 h after conidia germination. These results suggest that environmental factors have little effect on the variable induction of appressorium formation on the artificial surface in M. grisea.

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The Effects of Borax on Formation of Modified Belite Cement Minerals (Modified Belite Cement 구성광물의 생성에 미치는 붕상의 영향)

  • 채우형;최상홀
    • Journal of the Korean Ceramic Society
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    • v.33 no.10
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    • pp.1163-1169
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    • 1996
  • The effects of borax on the phase formation of C2S, C4A3 and $\alpha$'-C2S phases. It has negative effects on formation of C4A3 And it lowers the forming temperature of C4AF. It also has been found that borax improves the clinkerization of MBC. In the MBC clinker with borax 3% C2S have larger and more irregular shapes, larger C/S mole ratio and C4A3 have smaller size larger C/ molr ratio than in the clinker without borax.

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Thermodynamic Consideration for SiC synthesis by Using Sludged Silicon Powder (폐슬러지를 이용한 SiC 합성에 관한 열역학적 고찰)

  • 최미령;김영철
    • Journal of the Semiconductor & Display Technology
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    • v.2 no.1
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    • pp.21-24
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    • 2003
  • Sludged silicon powders that are generated during silicon ingot slicing process have potential usage as silicon source in fabricating silicon carbide powders by adding carbon. A thermodynamic calculation is performed to consider a plausible formation condition for the silicon carbide powders. A thin silicon oxide layer around silicon powder is sufficient to supply equilibrium oxygen partial pressure at the formation temperature($1400^{\circ}C$) of the silicon carbide in the Si-C-O ternary system. Formation of silicon carbide by using the sludged silicon powders is more efficient than by using silicon oxide powders.

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Origami inspired Temperature Sensor based on Stimuli-Responsive Hydrogel (종이접기 기반 자극 반응성 하이드젤 온도 센서 연구)

  • Na, Jun-Hee
    • Journal of Sensor Science and Technology
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    • v.26 no.1
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    • pp.35-38
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    • 2017
  • A thermally responsive hydrogel has reversibility with temperature during swelling. Here, we proposed origami inspired temperature sensor by using multi-layered hydrogel film. The formation of patterned stripes on microscale film drives bending to an angle that can be controlled linearly. Although temperature range was not wide, measured sensitivity of sensors has high resolution and accuracy. It providing a powerful platform for the design of sensitive sensors and that easily adapt other type of sensors in microscale.