• 대한화장품학회지
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• 제36권4호
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• pp.259-263
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• 2010

화장품에서 일반적으로 사용되고 있는 대표적인 자외선차단 원료들과 방부제인 phenoxyethanol (PE), 항균효과가 있는 ethylhexylglyceirn (EG)의 분배계수와 흡착도를 측정하여 비교하였고, 제품의 포장재 재질에 따라 PE가 흡착되는 정도를 비교하였다. PE, EG에 대한 11개 자외선 차단제의 분배계수는 EG가 상대적으로 높게 나타났으며 그중 Tinsorb M, Solaveil CT434가 높은 분배계수를 보였다. 40 % 이상의 EG 흡착을 보인 자외선 차단 원료는 Gransil PSQ, UV Titan M 160, Micro $TiO_2$ MT 100 TV였고, Gransil PSQ와 Scadder는 40 % 이상의 PE를 흡착하였다. 또한 PE는 포장재 원료인 polyoxymethylene에 의해 1개월 후 7 ~ 8 % 흡착됨을 확인하였다. 자외선차단제품의 방부처방을 설계할 때 사용되는 자외선 차단제와 방부제와의 상관성을 고려하여 적절한 방부제 및 차단제를 선정해야 적은 방부제로도 최적의 방부력을 갖는 제품 설계가 가능함을 보여준다. 또한 포장재의 종류에 따라 시간이 경과하면서 방부제가 포장재에 흡착되어 방부력이 저하될 수 있음을 확인하였다.

• 한국항해항만학회지
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• 제30권9호
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• pp.767-772
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• 2006

Generally, a silicone rubber and a chlorinated polyethylene(CPE) have been used as a binder for the development of high-performance composite EM(Electro Magnetic) wave absorbers. In this paper, the EM wave absorption performance of natural lacquer, which is newly proposed as a binder was investigated. The prepared MnZn ferrite EM wave absorbers are mixed with natural lacquer showed excellent EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers which are mixed with the conventional binders. MnZn ferrite EM wave absorbers mixed with natural lacquer were prepared and their absorption ability was also investigated The EM wave absorbers are fabricated in different proportions of MnZn, or NiZn ferrite and natural lacquer, and their reflection coefficients are measured. The permittivity and permeability are calculated by using the measured reflection coefficients. The EM wave absorption abilities are calculated according to different thicknesses of the EM wave absorbers.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.157-161
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• 2006

Generally, a silicone rubber and a chlorinated polyethylene(CPE) have been used as a binder for the development of high-performance composite EM(Electro Magnetic) wave absorbers. In this paper, the EM wave absorption performance of natural lacquer, which is newly proposed as a binder was investigated. The prepared MnZn ferrite EM wave absorbers are mixed with natural lacquer showed excellent EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers which are mixed with the conventional binders. MnZn ferrite EM wave absorbers mixed with natural lacquer were prepared and their absorption ability was also investigated. The EM wave absorbers are fabricated in different proportions of MnZn, or NiZn ferrite and natural lacquer, and their reflection coefficients are measured. The permittivity and permeability are calculated by using the measured reflection coefficients. The EM wave absorption abilities are calculated according to different thicknesses of the EM wave absorbers.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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• pp.41-47
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• 2002

A model of simultaneous heat and mass transfer process in absorption of refrigerant vapor into a lithium bromide solution of water-cooled vertical plate absorber was developed. The model can predict temperature and concentration profiles as well as the absorption heat and mass fluxes, the total heat and mass transfer rates and the heat and mass transfer coefficients. Besides, the effect of operating condition on absorption mass flux has been investigated, with the result that the absorption mass flux is increased as the inlet cooling water temperature decreases, the system pressure increases and the inlet solution concentration increases. And among the effects of operating parameters on absorption mass flux, the effect of inlet solution concentration is dominant.

• 한국소음진동공학회논문집
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• 제18권1호
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• pp.71-79
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• 2008

A helmholtz resonator has been widely used for the purpose of suppressing the low frequency noises propagated from various heat and fluid machineries. However, the conventional resonator has demerits that the effective absorption bandwidth is narrow and the absorption performance is not so outstanding in the only limited configurations of neck and cavity as well. In order to overcome these problems, in this paper, a resonator with perforated neck is proposed. The absorption performances of the resonator are measured by two-microphone method and estimated by transfer matrix method. The measured values of normal absorption coefficients agree well with the estimated values. By introducing the perforated plates at the neck of a resonator, it is shown that the absorption performance have been significantly improved.

• Journal of the Korean Wood Science and Technology
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• 제32권6호
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• pp.50-56
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• 2004

This study was conducted to investigate the performance of sound absorption type-noise barriers manufactured with a combination of wood particles used for particleboard, recycled waste newspaper, and cement. An average density of wood-combined cement board was in the range from 0.83 to 0.96 g/cm³, showing relatively low-density board. Regardless of types of cement bonded board or wooden board, the board with concave holes(凹)-formed surfaces showed greater sound absorption coefficient compared to those of flat surface boards. The board density was not related with those coefficients. Accordingly, it was concluded that concave or deep corrugated surface structure has played an important role in sound absorption for the application of sound absorption type-noise barrier.

• Journal of the Korean Wood Science and Technology
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• 제38권6호
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• pp.457-462
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• 2010

적절한 용도개발이 필요한 조선산업 폐합판의 흡음성능과 기계적 성질을 파악하고자 메이플과 메란티 폐합판을 적층하고 재단하여 폐합판재활용보드를 만들어 전달함수법으로 흡음율을 측정하고 휨강도를 측정하였다. 메이플과 메란티에서 제작된 폐합판 적층 보드의 최대강도는 각각 534와 414 kgf/$cm^2$으로 나타나 상용합판과 비교하여 비슷한 강도성능을 나타내었다. 측정주파수범위에서 메란티 폐합판재활용보드의 흡음율은 0.25 전후의 수치를 나타내어 비교 대상인 섬유판과 신갈나무 시험편보다 높은 흡음율을 나타내었다. 폐합판 재활용보드의 측면을 슬라이스절삭하여 제작한 보드는 우수한 강도적 성능과 흡음성능으로 실내장식재로의 재활용이 기대되었다.

• 반도체디스플레이기술학회지
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• 제9권2호
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• pp.33-39
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• 2010

The moisture absorption properties such as diffusion coefficient and moisture content ratio of liquid type epoxy resin systems with the filler were investigated. Bisphenol A type and Bisphenol F type epoxy resin, Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these liquid type epoxy encapsulant according to the change of filler size. The temperature of glass transition (Tg) of these epoxy resin systems was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these epoxy resin systems according to the change of time were observed at $85^{\circ}C$ and 85% relative humidity condition using a thermo-hygrostat. The diffusion coefficients in these systems were calculated in terms of modified Crank equation based on Ficks' law. An increase of Tg and diffusion coefficient with filler size in these systems can be observed, which are attributed to the increase of free volume with Tg. The change of maximum moisture absorption ratio according to the filler size and filler content cannot be observed; however, the diffusion coefficients of these systems decreased with filler content. The diffusion via free volume is dominant in the epoxy resin systems with low nano-sized filler content; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the liquid type epoxy encapsulant with high nano-sized filler content.

• 전자공학회논문지D
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• 제35D권8호
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• pp.44-52
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• 1998

The theoretical modeling of transition energy and absorption coefficient for intersubband transitions in quantum wells in presented. We include, as well as hartree and exchange-correlation potentials, boht depolarization effect and exciton-like effect which play great roles in heavily doped cases where practically reasonable absorption coefficients are available. Also, the calculated results are compared with the existing experimental values for .delta.-doped Si quantum wells to check the validity of our theoretical calculation.

• 태양에너지
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• 제9권3호
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• pp.73-80
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• 1989

This paper presents as assessment based on steady-state thermodynamic analysis and computer modeling of a double effect generation absorption heating cycle for solar air-conditioning to find operating temperature ranges. The influences of component temperatures on the heating coefficients of performance and mass flow ratio have been investigated to obtain optimum operating conditions for the proposed air conditioning system. And the single and double effect absorption cycles are compared with each other over the same range of temperatures.