• Korean Journal of Optics and Photonics
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• v.15 no.5
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• pp.449-454
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• 2004

The optical limiter is an optical component which reduces laser beam intensity for the protection of eyes and light sensors. Carbon nanotube is now known as a highly efficient optical limiting material. Optical limiting effect of the multi-walled carbon nanotube suspensions, in several kinds of solvents such as distilled water, chloroform, ethanol and ethylene glycol, were measured in the range from room temperature to near to the boiling points of the solvents. The pulsed Nd:YAG laser whose wavelength is 1064 nm and pulse duration is 6 ns was used as a light source. The experimental result shows that the limiting efficiency was reduced as the temperature increased, and the suspension which has lower boiling point, viscosity and surface tension has highest efficiency.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.127-130
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• 2004

벤젠과 사이클로헥산을 투과증발법을 이용하여 분리하는 경우에는, 벤젠과 사이클로헥산의 물리적 성질이 비슷하고, 그 끓는점이 매우 비슷하기 때문에, 물리화학적인 특성을 먼저 알아야 한다. 벤젠은 이중결합을 가지고 있고, 공명구조를 이루고 있다. 즉 극성기와 강한 상호작용을 할 수 있는 파이전자를 벤젠이 가지고 있음을 주목하여야 한다.(중략)

• Journal of the Korean Chemical Society
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• v.46 no.3
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• pp.252-264
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• 2002

In this study, the experimental apparatus for boiling point and melting point in science textbooks of various curriculums were analyzed. Science teachers' views on the difference between the experimental value and the value written in textbooks were inquired, too. Their views on the experimental apparatus, nd results of freezing point,melting point, boiling point, fractional distillation, and thermometer calibration were also investigated. The results of this study showed that the types of experimental apparatus for boiling point and melting point were somewhat dif-ferent with science textbooks and curriculum. The teachers' views were also various according to their background. In the experiment of the fractional distillat ion, a large number of teachers recognized mismatch between the exper-imental value and the value written in textbooks as mistake of textbook contents or problem of experiment itself. The teachers of chemistry background take higher recognition of the requirement of thermometer calibration than those of non-chemistry background in middle school.

• Journal of the Korean Chemical Society
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• v.46 no.6
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• pp.523-527
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• 2002

Partition coefficient related composition of LPG are studied. Analysed sulfur compounds are ethyl mer-captan,n-propyl mercaptan and n-butyl mercaptan. The composition of liquid phase and gas phase in LPG are deter-mined by gas chromatography. The partition coefficient to related the boiling point of sulfur compounds, the temperature and the compositions of solvents, determined by using MLR(multiple linear regression) of SAS is follows; Kpc= $0.61222({\pm}0.6578)-0.04670({\pm}0.000959)Bp+0.26984(\pm0.06504)C4+0.003803(^{\circ}ae0.0019993)Tk,$ N=24, F=14.851, $R^2_{adj}$=0.6437. The boiling points of sulfur compounds at atmospheric pressure and the compositions of LPG effect mostly on partition coefficients. It is presumed that the gas odor elevating effects should be increased, where being on high tem-perature and larger amounts of n-butane.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.8
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• pp.759-763
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• 2015

The laser machining process has been proposed as an advanced process for the selective fabrication of electrodes without a mask. In this study, we adapt laser machining to metals that have different thermal properties. Based on the results, the metals exhibit a different surface morphology, heat-affected zone (HAZ), and a recast layer around the machined surface according to their thermal conductivity, boiling point, and thermal diffusivity. Then, we apply ultrasonic-assisted laser machining to remove the recast layer. The ultrasonic-assisted laser machining exhibits a better surface quality in metals with higher diffusivity than those having lower diffusivity.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.184-184
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• 2001

The effect of neutral ligand(L) on the precursor characteristics of (hfac)Cu(I)-L and on Cu MOCVD Process was studied. The neutral ligands of (hac)Cu(I)-L$_{x}$, such as ATMS(allytrimethylsilane), VTMS(vinyltrimethylsilane), VCH(vinylcyclohexane), MP(4-methyl-1-pentene), ACP(allylcyclopentane), and DMB(3,3-dimethyl-1-butene) were investigated. When the dissociation temperature of Cu(I)-L bond is low, low temperature deposition below $100^{\circ}C$ is possible and the resistivity of the film is low. But thermal stability of the precursor is low in this case. The resistivity is almost the same regardless of L at the deposition temperature range of $125~175^{\circ}C$. The resistivity is increased as the molecular weight of L becomes higher above $225^{\circ}C$ The vapor pressure of the precursor was closely related to the boiling point of L, the lower the boiling point of L, the higher the vapor pressurere.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.185-190
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• 2001

The effect of neutral ligand(L) on the precursor characteristics of (hfac)Cu(I)-L and on Cu MOCVD Process was studied. The neutral ligands of (hac)Cu(I)-L$_{x}$, such as ATMS(allytrimethylsilane), VTMS(vinyltrimethylsilane), VCH(vinylcyclohexane), MP(4-methyl-1-pentene), ACP(allylcyclopentane), and DMB(3,3-dimethyl-1-butene) were investigated. When the dissociation temperature of Cu(I)-L bond is low, low temperature deposition below $100^{\circ}C$ is possible and the resistivity of the film is low. But thermal stability of the precursor is low in this case. The resistivity is almost the same regardless of L at the deposition temperature range of $125~175^{\circ}C$. The resistivity is increased as the molecular weight of L becomes higher above $225^{\circ}C$ The vapor pressure of the precursor was closely related to the boiling point of L, the lower the boiling point of L, the higher the vapor pressurere.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.1
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• pp.8-12
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• 2014

Reduced pressure evaporation applies the principle of lowering water's boiling point by reducing the pressure. It uses the relation between temperature and pressure to reduce energy consumption needed for elevating temperature. As the result, the highest evaporation was observed at $80^{\circ}C$ and -40 cmHg applying saturated vapor pressure depending on different seawater temperature. It was found that the higher concentration in the factor test experiment depending on seawater concentration induced the higher evaporation. Also, in the factor test experiment, the amount of evaporation increased as the pressure decreased. It is concluded that the most important factor of evaporation was concentration, the second important factor was temperature, and the least important factor was pressure. Through this experiment, optimized conditions of desalination with reduced pressure evaporation device were verified.

• Journal of the Korean Society of Safety
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• v.13 no.4
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• pp.192-198
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• 1998

MRSM(modified response surface methodology)-2 model is presented for the prediction of boiling points in combustible solution of quaternary systems. This model requires only normal boiling points of pure substances and group-group parameters which are based on the group-group concepts without the use of experimental data under consideration. By means of this methodology, it is possible to predict the boiling points of the combustible mixture of quaternary systems by plotting of isothermal lines using computer graphics. The proposed methodology has been tested and compared successfully with reported boiling points in journals for the combustible solution of quaternary systems. It is hoped eventually that this methodology will permit prediction of the flash point and flammability limit for the combustible mixture of multicomponent systems.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.36-37
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• 1995

투과증발법은 기존의 증류법에 의해 분리되기 어려운 혼합물(공비혼합물이나 끓는점이 비슷한 혼합물)이외에 열에 민감한 생성물의 분리, 과익쥬스의 농축, 불순물 찌꺼기의 제거, 정량 검출을 위한 유기 오염물질의 농축 등에 이용되었으며 특히 물과 에탄올의 공비혼합물의 분리와 물로부터 희박 유기물질을 회수하는데 행해져 왔다. 본 연구에서 사용된 키토산은 친수성기들을 가지고 있기 때문에 물과 알코올의 분리에서 물을 선택적으로 투과시켜 효과적인 투과증발막으로 사용될 수 있으며 투과속도를 높이기 위해서 활성층이 매우 얇은 복합막을 제조하였다. 또한 키토산 복합막을 다양한 가교제 (glutaraldehyde, glyoxal, terephthalaldehyde, 황산등)로 가교한 막들을 열처리를 하거나 키토산과 PVA를 블렌드하여 제조한 키토산/PVA 블렌드 복합막을 이용하여 에탄올/물, IPA/물 혼합용액에서의 탈수 실험을 실시하여 이에 따른 투과성능의 영향을 살펴보았다.