• 제목/요약/키워드: formation effects

검색결과 6,034건 처리시간 0.034초

엔진 오일 열화와 피스톤 온도가 카본 디포짓 형성에 미치는 영향 Part I-가솔린 엔진의 디포짓 형성 특성 (The Effect of Gasoline Engine Oil Degradation and Piston Temperature on Carbon Deposit Formation; Part I-Characteristics of deposit formation on gasoline engine)

  • 김중수;민병순;이두순;오대윤;최재권
    • Tribology and Lubricants
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    • 제13권4호
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    • pp.33-39
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    • 1997
  • In order to establish a new temperature criterion to prevent the pistons from ring sticking due to deposit formation, bench test and engine test were performed. The effects of oil degradation and temperature on deposit formation was studied by a modified panel coking test. Oil degradation was analyzed by FTIR. Oil oxidation and nitration were selected as a factors to evaluate oil degradation. Bench test results show that oil oxidation is more effective to the deposit formation than oil nitration. And the temperature increase accelerates deposit formation and deposit formation increase rapidly above 26$0^{\circ}C$. Especially, in case of degraded oil, the deposit formation increases so rapidly that ring sticking can occur. The effect of piston temperature on the deposit formation was confirmed by engine test.

Numerical Modeling of Combustion Processes and Pollutant Formations in Direct-Injection Diesel Engines

  • Kim, Yong-Mo;Lee, Joon-Kyu;Ahn, Jae-Hyun;Kim, Seong-Ku
    • Journal of Mechanical Science and Technology
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    • 제16권7호
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    • pp.1009-1018
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    • 2002
  • The Representative Interactive Flamelet (RIF) concept has been applied to numerically simulate the combustion processes and pollutant formation in the direct injection diesel engine. Due to the ability for interactively describing the transient behaviors of local flame structures with CFD solver, the RIF concept has the capabilities to predict the auto-ignition and subsequent flame propagation in the diesel engine combustion chamber as well as to effectively account for the detailed mechanisms of soot formation, NOx formation including thermal NO path, prompt and nitrous 70x formation, and reburning process. Special emphasis is given to the turbulent combustion model which properly accounts for vaporization effects on the mixture fraction fluctuations and the pdf model. The results of numerical modeling using the RIF concept are compared with experimental data and with numerical results of the commonly applied procedure which the low-temperature and high-temperature oxidation processes are represented by the Shell ignition model and the eddy dissipation model, respectively. Numerical results indicate that the RIF approach including the vaporization effect on turbulent spray combustion process successfully predicts the ignition delay time and location as well as the pollutant formation.

A Dynamic Price Formation System and Its Welfare Analysis in Quantity Space: An Application to Korean Fish Markets

  • Park, Hoan-Jae
    • 수산경영론집
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    • 제41권2호
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    • pp.107-133
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    • 2010
  • As policy makers are often concerned about dynamic effects of demand behavior and its welfare analysis by quantity changes, the paper shows how dynamic price formation systems can be built up to analyze the effect of policy options to the markets dynamically. The paper develops dynamic model of price formation for fish from the intertemporal optimization of the consumer choice problem. While the resulting model has a similar form of the error correction types of dynamic price formation system, it provides the rational demand behavior contrary to the myopic behavior of error correction demand models. The paper also develops appropriate tools of dynamic welfare analysis in quantity space using only short-run demand estimates both theoretically and empirically as a first attempt in the literature of price formation and fisheries. The empirical results of Korean fish markets show that the dynamic model and the welfare measures are reasonably plausible. The methodology and theory of this research can be applied and extended to the commodity aggregation, dynamic demand estimation, and dynamic welfare effects of regulation in the similar framework. Thus, it is hoped that this will enhance its applications to the demand-side economics.

저선량 방사선이 MC3T3-E1 골모세포주의 석회화결절 형성에 미치는 영향 (Effects of low dose irradiation on the calcific nodule formation in MC3T3-E1 osteoblastic cell line)

  • 김경아;고광준
    • Imaging Science in Dentistry
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    • 제34권3호
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    • pp.137-144
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    • 2004
  • Purpose: To investigate the effects of low dose irradiation on the calcium content and calcific nodule formation of the MC3T3-El osteoblastic cell line. Materials and Methods: Cells were irradiated with a single dose of 0.2, 0.4 and 0.6 Gy at a dose rate of 5.38 Gy/min using Cs-137 irradiator. After irradiation, the calcium content and calcific nodule formation were examined on the 1st, 2nd, 3rd and 4th week. Results: We did not find any significant difference of total calcium content after irradiation of 0.2, 0.4 and 0.6 Gy when compared with the unirradiated control group. There was no significant difference of total calcium content between 0.2, 0.4 and 0.6 Gy irradiated groups. We found an increased tendency of the calcific nodule formation after irradiation of 0.2, 0.4 and 0.6 Gy when compared with the unirradiated control group without significant difference of calcific nodule formation between 0.2, 0.4 and 0.6 Gy irradiated groups. Conclusion : The results showed an increased tendency of the calcific nodule formation after low dose irradiation. However, this tendency did not increase with the increase of irradiation dose.

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Effects of Social Media Utilization on Labor Union Social Capital in South Korea

  • Lee, Ji-Heon;Jung, Hoe-Kyung
    • International journal of advanced smart convergence
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    • 제6권2호
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    • pp.34-50
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    • 2017
  • This study delved into the effects of labor union members' social media utilization for the formation of labor union social capital. Specifically, this study aimed to identify the effects of labor union-related social media use and participation on the labor union's social capital formation through quantitative and qualitative research. It set up trust, network, and participation as social capital components and as dependent variables. Network, in particular, was divided into bonding and bridging aspect. There is the correlation between labor union-related social media use and the formation of labor union social capital. As participation in the group type social media operated by a labor union becomes more active, evaluation on labor union social capital throughout trust, network, and participation is higher. Especially, the correlation between bonding network and bridging network was high. This proves that a labor union's bond enhancement does not result in the labor union's selfishness, but it can build a cooperative system with an external network.

와동과 상호작용하는 화염편에서의 오염물질 생성특성 (Pollutant Formation Characteristics in a Flamelet Interacting with a Vortex)

  • 오창보;이의주
    • 한국안전학회지
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    • 제25권1호
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    • pp.9-16
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    • 2010
  • Flame structure of diffusion flame interacting with a single vortex was investigated with direct numerical simulation (DNS). A well-known counterflow diffusion flame was used as an initial flat flame and single vortices were made by issuing a high-velocity jet abruptly in fuel- and air-side. The variations in the maximum concentration of major species (CO and $CO_2$) and NOx (NO and $NO_2$) with the stoichiometric scalar dissipation rate were investigated. Unsteady effects in the species concentration variation of the flame interacting with a vortex were identified by comparing with that of steady flame. $NO_2$ formation characteristics of the flame interacting with a vortex were well understood by investigating the $HO_2$ formation. To enhance the prediction performance in the fire simulation, current turbulent combustion modelings are needed to be modified by adopting the unsteady effects in the species concentrations of diffusion flame interacting with a vortex.

Asymbiotic seed germination and in vitro propagation condition in Calanthe discolor Lindl.

  • Kwon, Huyk Joon;Shin, So Lim;Bae, Kee Hwa;Kim, Soo-Young
    • Journal of Species Research
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    • 제6권1호
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    • pp.68-75
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    • 2017
  • We investigated the effects of sodium hypochlorite (NaOCl) and culture medium on embryo swelling and germination of Calanthe discolor Lindl., and established a method for determining the swelling and protocorm formation of C. discolor seeds via in vitro examination of immature seeds. Treatment of immature seeds with NaOCl greatly enhanced the extent of embryo swelling and protocorm formation of immature zygote embryos compared to seeds without NaOCl treatment. The effects of the culture media were also evaluated with regard to embryo swelling and protocorm formation of in vitro cultured seeds with and without NaOCl treatment. Additionally, the effects of white fluorescent light and red and blue LEDs lights on seedling growth in in vitro culture were examined. The most suitable condition for seedling growth after 12 weeks of culture was the red LEDs light with POM medium. These results show effective asymbiotic germination and growth of C. discolor.

Effects of Oxygen Annealing of MgO Thin Films on the Phase Formation and the Electrical Properties of PZT/MgO/Si Structure

  • Song, Han-Wook;No, Kwang-Soo
    • The Korean Journal of Ceramics
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    • 제6권1호
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    • pp.68-73
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    • 2000
  • The effects of oxygen annealing on the carbon content in MgO thin films were investigated, MgO thin films were deposited on Si(100) substrate at different temperatures of 400 to $700^{\circ}C$ and different deposition rates of 3.4 to 11.6$\AA$/min. Using rf magnetron sputtering method. Carbon content change on the surface of MgO thin films with the oxygen annealing at different temperatures was investigated using various method. The carbon content decreased as the annealing temperature increased. $Pb(Zr_{0.53}Ti_{0.47})O_3$(PZT) thin films were deposited on the MgO/Si(100) substrates. The effects of carbon content on the phase formation and the electrical properties of PZT thin films were also investigated.

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지각자의 성격변인에 따른 의복단서의 인상효과에 대한 연구 (Effects of Clothing Cues and Perceiver's Personality Traits Variables on Impression Formation)

  • 이현화;박찬부
    • 한국의류학회지
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    • 제22권3호
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    • pp.341-352
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    • 1998
  • The purpose of this study was to investigate the effect of clothing cues (color, color scheme, structure) on impression formation by perceiver personality variable. The subjects were consisted of 77 male and 86 female undergraduate and graduate students. The experimental inventories for this study were a set of stimuli, a response scale, standardized MBTI. The stimuli were eighteen photographs and one extra photograph of a female wearing Korean dress, Chima and Jokori-varied in hue (cool, warm), color scheme (related schemes, con- trasting schemes) of the same silhouette. Results indicate that the most affecting perceiver's personality variables on impression effects were judging-perceiving traits and extraversion -introversion traits. The interaction effects were most frequently appeared between color scheme (clothing cues) and perceiver's personality traits. The impression factors which were most affected by perceiver's personality traits variables were preference· evaluation factor and individuality· attention factor.

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Effects of Specific Interaction Altering Reagents on Hardnesses of Succinylated Soy Protein Gel

  • Bae, Dongho;Jung, Hosun;Choi, Yong-Hee
    • Journal of Applied Biological Chemistry
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    • 제42권3호
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    • pp.125-129
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    • 1999
  • The changes in gel characteristics of soy protein and succinylated soy protein due to various specific interaction-altering reagents which affect the formation and textural properties of gels, were studied. The reagents were added to 15% soy protein solutions prior to heat treatment. Succinylated soy protein formed harder gel without the addition of reagents. Hardly no gels were formed with urea, indicating that hydrogen bonds significantly contributed to the formation and hardness of the gel and the effects of urea on the hardness of succinylated soy protein gel were more significant. Disulfide bonds were important in the formation of hard gels whether they were succinylated or not, but the contributions of hydrophobic interactions to gel hardness were relatively insignificant. The hardness reducing effects of NaCl and NaSCN were more significant in succinylated soy protein gel. As such, electrostatic interactions were important for succinylated soy protein to form hard gel but not for unmodified soy protein.

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