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김광제;박인준;김동권;이수복
- Membrane Journal
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- v.5 no.2
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- pp.74-80
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- 1995
Asymmetric poly(vinyl alcohol) (PVA) membranes were prepared by varying the precipitation conditions of the phase inversion technique, and the influences of precipitation conditions on the water uptake of the membrane were investigate. The degree of water uptake of the membrane increased and reached a certain maximum value, as the precipitation time increased. However, it decreded after that. As the precipition temperauure became lower, the degree of water uptake increased more or less. The addition of a nonionic surfactant to the precipitaon solution was effective reducing the precipitation time by lowering the surface tension of the precipitation solution, but ig didn't change the maximum value of its own degree of water uptake. In addition, the relationship between the degree of water uptake and the separation characteristics and mechanical properies of the membrane were investigated. The selectivity factor of the membrane for pervaperation separation decreased, but the permeate flux increased, respectively, with increasing the degree of water uptake. The tensile strength and elongation of the membrane, respectively, increased to a maximum value with increasing the degree of water uptake, and then decreased abtuptly.
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이지이;배수야;이승묵;김용표
- Proceedings of the Korea Air Pollution Research Association Conference
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- 2001.11a
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- pp.37-38
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- 2001
Polycyclic Aromatic Hydrocarbons(다환방향족 탄화수소류, 이하 PAHs)는 두 개 이상의 벤젠 고리로 구성되어 있는 반휘발성 유기물질로서 가스상과 입자상에 모두 존재한다. PAHs는 주로 불완전 연소에 의해서 생성되며, 주요 고정 오염원은 주거 난방, 코크 산업, 소각이고, 주요 이동오염원은 자동차 엔진이다. PAHs에는 강한 발암성 혹은 돌연변이원성을 가진 화합물들이 포함되어 있고, 주변 대기에 널리 분포되어 있을 가능성이 높기 때문에 일반 대중이 쉽게 노출될 수 있다. (중략)
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Jeong, In-Ha;Bae, Gi-Gwang
- Korean Journal of Materials Research
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- v.8 no.9
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- pp.783-790
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- 1998
New process development of nuclear fuel fabrication for nuclear power plant was attempted by induction plasma technology with yttria-stabilized-zirconia ($\textrm{ZrO}_{2}$-$\textrm{Y}_{2}\textrm{O}_{3}$)powder, similar to $\textrm{UO}_{2}$, in the respect of melting point and physicochemical characteristics. Extent of powder melting was affected greatly by plasma plate power and particle size. Being optimized such as, sheath gas composition, probe position, particle size and spraying distance, dense deposit of 97.91% T.D. with deposition rate 20mm/min was attained at the condition of 120/20$\ell$/min of Ar/$\textrm{H}_{2}$ flow rate, 80kw of plate power, 8cm of probe position, 200Torr of chamber pressure and 18cm of spraying distance. The pellet of 96.5% of theoretical density was formed with homogeneity and nice exterior view at the best condition of deposition experiments, and the possibility of new nuclear pellet fabrication process was confirmed. The main and interrelated effects on deposit density were assessed by ANOVA(Ana1ysis of Variance).
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