• Title/Summary/Keyword: physical conditions

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A Case Study on Speed Analysis of the Rear-end Collision Accident (자동차 추돌사고 속도분석에 관한 사례 연구)

  • Kim, Daebong;Yun, Daekwon;Park, Jeongho;Ha, Seongyong;Park, Jechul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.6
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    • pp.724-729
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    • 2016
  • This case study carried out a rear-end collision accident analysis and physical simulation of an SUV and passenger car. The speed of the SUV by physical analysis is 71 ~ 87 km/h, while the speed of the passenger car is 6 ~ 22 km/h. Simulation results showed the optimal speed conditions for the SUV was 71 km/h, and 7 km/h for the passenger car. Simulations can be verified for the collision analysis. The findings of this study are expected to increase the reliability of accident reconstructions.

A Study on the Achievement of Readiness for School in First Grade Children (학령기를 맞는 어린이의 생활능력에 관한 연구)

  • 박상인
    • Journal of the Korean Home Economics Association
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    • v.19 no.2
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    • pp.57-71
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    • 1981
  • This study in an attempt to analyze the child's readiness for school and to pursue the facts that influence the readiness. the child's readinees for school was analyze on the developmental tasks in terms of physical, intellectual, social and moral development of first graders. On the facts that influence the readiness, age, sex, home environment and preschool experiences were surveyed. Ⅰ. Objectives 1. To survey the actual developmental conditions of physical, intellectual, social, and moral development of first graders. 2. To analyze the differences of school readiness in of sex, age and birth order. 3. To analyze the influence of home environment and preschool experience upon readiness. 4. To survey the differences of evaluation between parents and teachers on achievements of readiness. Ⅱ. Method 1. subjects were 848 mothers of primary school first graders and 20 primary school teachers. By the stratifeed sampling method, Seoul city was divided into three types of districts. 2. measurement tool was the check test for the child's readiness for school.

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Structure and Physical Conditions in MHD Jets from Young Stars

  • SHANG HSIEN
    • Journal of The Korean Astronomical Society
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    • v.34 no.4
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    • pp.297-299
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    • 2001
  • We have constructed the foundations to a series of theoretical diagnostic methods to probe the jet phenomenon in young stars as observed at various optical forbidden lines. We calculate and model in a self-consistent manner the physical and radiative processes which arise within an inner disk-wind driven magneto centrifugally from the circumstellar accretion disk of a young sun-like star. Comparing with real data taken at high angular resolution, our approach will provide the basis of systematic diagnostics for jets and their related young stellar objects, to attest the emission mechanisms of such phenomena. This work can help bring first-principle theoretical predictions to confront actual multi-wavelength observations, and will bridge the link between many very sophiscated numerical simulations and observational data. Analysis methods discussed here are immediately applicable to new high-resolution data obtained with HST and Adaptic Optics.

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Physico-chemical Behavior of Polymeric Hydrogels

  • Soh, Dae-Wha;Mun, G.A.;Nam, Irina;Nurkeeva, Z.S.;Shaikhutdinov, E.M.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.592-595
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    • 2002
  • New polymeric hydrogels based on vinyl ethers have been synthesized by the ${\gamma}$-initiated polymerization method. Their physical chemistry and physical mechanical properities have been studied. It has been shown that structure and swelling behavior of the hydrogels can be regulated by the changing of synthesis conditions nature of monomers. Novel stimuli-sensitive polymers have been synthesized by the varying of macrochains hydrophilic-hydrophobic balance. The some biomedical aspects of application of hydrogels in capacity of drain aging polymeric materials in ophthalmology surgery, implants in plastic surgery as well as drug delivery systems have been investigated.

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A Study on the Development and Application of Thermal Evaporation Source (Thermal Evaporation 증발원 개발 및 응용에 관한 연구)

  • Kim, Kwan-Do
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.3
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    • pp.19-22
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    • 2020
  • The thermal evaporation source is used to prepare thin films by physical vapor deposition. Materials of metals, organic materials, were tested and explained for thermal evaporation experiments. The developed effusion cell performance depends on the type of deposition material, the size of the crucible, the performance of the reflector, etc. and the proper conditions were found by producing, comparing and analyzing several sets of effusion cell to quantitatively evaluate the performance of the cell. The effusion cell for thermal evaporation source is used to prepare thin films of Ag, Cu, Mg.

Removal Effect of Odor Gases Generated in Foaming Process of Shoes Insole with Addition of Self Actuated Photocatalyst Prepared by Sol-gel Method

  • Choi, Sei Young
    • Elastomers and Composites
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    • v.50 no.2
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    • pp.132-137
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    • 2015
  • A self actuated photocatalyst $Weltouch^{(R)}$ used to the remove the odor gases generated in the foaming process of shoes insole was prepared by sol-gel method and studied its property. Specially, with mixing $Weltouch^{(R)}$ in the foaming process of shoes insole, the physical functionality such as specific gravity, hardness, elongation, compression set was studied. The physical functionality of shoes insole was no variation by added $Weltouch^{(R)}$. The odor gases generated in the foaming process of shoes insole was detected to be reduced to 60~80% by self actuated photocataylst $Weltouch^{(R)}$ even in the dark conditions, which was observed for both anatase and rutile phase.

Power Dependence on Formation of Polyynes by Laser Ablation in Water

  • Park, Young Eun;Shin, Seung Keun;Park, Seung Min
    • Bulletin of the Korean Chemical Society
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    • v.34 no.4
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    • pp.1039-1042
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    • 2013
  • Polyynes were prepared by liquid laser ablation of a graphite target in deionized water at various physical conditions such as laser power (20 and 40 mJ/pulse) and ablation wavelengths (355, 532, and 1064 nm). The effects of physical parameters on the linear carbon chain length were examined by analyzing the densities of polyynes with different carbon numbers ($C_6H_2$, $C_8H_2$, and $C_{10}H_2$) as well as their branching ratios. We concluded the photophysical processes turned out to play a more significant role than thermal ones in the formation of polyynes.

STUDIES ON THE CHLORINE OF BURLEY TOBACCO PLANTS III. THE EFFECTS OF LIME, PHOSPHORUS, IRON, MANGANESE AND BORON ON CHLORINE ABSORPTION, CHEMICAL CONSTITUENTS AND PHYSICAL PROPERTIES OF LEAF TOBACCO (버어리종 담배의 염소에 관한 연구 III. 석회, 인, 철, 망간 및 붕소시용이 담배의 염소흡수 및 이화학성에 미치는 영향)

  • 김상범;배길관
    • Journal of the Korean Society of Tobacco Science
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    • v.8 no.2
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    • pp.29-41
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    • 1986
  • Effects of some mineral nutrients on the chlorine absorption by the plants, on the chemical constituents and physical properties of leaves were investigated tinder the paddy field and pot conditions. The chlorine content of cured leaf grown in paddy field was high in iron and manganese application groups and highest in combined application of iron and manganese. Lime application inhibited the absorption of chlorine and increased the yield and quality of cured leaf, and inhibited the absorption of iron and manganese those causing the grey leaf. Lime application reduced the leaf chlorine content and rate of muddy grey leaf by increasing the soil pH in acid soil.

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A COMPARATIVE STUDY OF THE EFFECTIVENESS IN POLYMERIZATION OF COMPOSITE RESIN CURED WITH VISIBLE LIGHT AND ARGON LASER SOURCE (가시광선과 아르곤 레이저에 의한 복합레진 중합 효과의 비교 연구)

  • Jun, Sang-Eun;Kim, Yong-Kee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.23 no.2
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    • pp.327-346
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    • 1996
  • The purpose of this study was to evaluate the shear bond strengths, microhardness, compressive strength and contraction gap at the resin-tooth interface of two types of composite resins polymerized with visible light and argon laser sourse. The results from the present study can be summarized as follows ; 1. Resin samples polymerized either by argon laser or visible light did not show significant difference in their physical properties tested(p>.05). 2. The contraction gap at the resin tooth interface was found to be present in all samples but any significant difference between groups could not be established due to their variability. Although the superiority of argon laser over visible light in enhancing the physical properties of resin could not be elucidated in the present study, continous efforts are deemed to be worthwhile to investigate this area using different conditions and materials of experiment.

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Filmwise Condensation of Freon Vapor Including Air on a Horizontal Tube (공기를 함유한 프레온 증기의 수평관 외부에서의 막응축)

  • Kim, K.H.;Ko, H.J.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.1
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    • pp.20-29
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    • 1995
  • A theoretical model for film condensation of a vapor including a relatively lighter noncondensable gas on a horizontal tube has been formulated on the basis of the conservation laws and other fundamental physical principles. The model is applied to the prediction of the condensation heat transfer characteristics for the Freon vapor in the presence of air on a horizontal tube. Calculated results for the mean heat transfer coefficient, which is shown to depend strongly on the bulk concentration of air, are in good agreement with the available experimental results for a range of operating conditions. The distributions of physical quantities along the surface of tube are also calculated, such as the boundary layer thickness and local heat transfer coefficient. The present model is readily reduced to the Nusselt model as the bulk concentration of air decreases to zero. Therefore, the transition from the condensation of pure vapor to that of vapor-air mixture occurs continuously not abruptly.

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