• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.864-865
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• 1998

Permeation of $Ca^{2+}$ ions in PVC and flame-retardant polyolefin (FR) compounds for the sheath of medium voltage underground cables was studied. At $70^{\circ}C$ ion permeation increases fast at times of up to a few tens of hour and then at a relatively slow rate. The first fast increase was attributed to the diffusion of ions in the samples while the second slow increase of ion permeation was attributed to the permeation of $Ca^{2+}$ ions through the samples. It was also found that the diffusivity of $Ca^{2+}$ ions in FR compounds is much higher than that in PVC compounds.

• 산업기술연구
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• 제18권
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• pp.259-265
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• 1998

The molecular weights of surfactant SDS(M.W. 288) and SLS(M.W. 420) are smaller than the molecular weigh cut-off of cellulose acetate membrane used in this study. However, 20% of SDS and 67% of SLS were rejected by cellulose aectate membrane. The higher rejection rate of SLS than that of SDS is due to the longer hydrophobic chain and greater molecular weight. There was no resistance to permeation rate by membrane fouling. Most of permeation resistance was due to the concentration polarization. Permeation rate was declined with operating time and with increase in concentration of surfactant due to concentration polarization.

• 멤브레인
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• 제10권1호
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• pp.30-38
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• 2000

투과증발공정에서 polydimethylsiloxane(PDMS)막에 대한 용매의 수착특성과 투과 플럭스를 예측하는 방법을 제시하였다. 이 방법을 이용하여 chloroform, toluene, methoanol, n-butanol의 수착량과 투과 플럭스를 계산하였으며, 계산값과 실험값을 비교하였다. 팽윤을 촉진시키는 정용매(good solvent)인 toluene과 chloroform의 경우 계산된 수착량과 투과 플럭스는 실험값과 잘 일치하였다. 막의 밀도가 작을수록 수착량과 투과 플럭스는 증가하였다. 팽윤을 억제시키는 부용매(poor solvent)인 methanol, n-butanol의 경우는 실험값과 상당한 오차가 있었다. 따라서, 본 미케니즘에 의해 PDMS막에 대한 정용매의 수착량과 투과 플럭스는 실험에 의하지 않고도 이론적으로 예측할 수 있는 가능성을 보여주었다.

• 대한화장품학회지
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• 제23권3호
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• pp.108-114
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• 1997

The skin permeation study has two meanings in cosmetics. One is how to promote the skin permeation of active meterials for improving their bioavailabilities and the other is how to decrease it of irritants for reducing their skin side effects. In this study, we selected methyl paraben, one of the preservatives, as a model irritant and tried to reduce the skin irritation by the decrease of skin permeation. Furthermore, the relationship between skin permeation and skin primary irritation was discussed. For in vitro skin permeation experiments, Franz type diffusion cells and the excised skin of female hairless mouse from 8 weeks old were used. The donor compartment was charged with oil only or O/W emulsion containing 0.3% MP. We selected 19 oils, including esters, triglycerides, plant oils, hydrocarbons, and alchols, which are broadly used in cosmetics. We evaluated with female guinea pig. The skin permeahility of MP from the oils showed following order: ester oils > triglycerides > plant oils > hydrocarbons > alcohols. We considered that this result was based on the different effect of each oil on the barrier function of stratum corneum. In O/W emulsion containing each oil, the skin permeability of MP decreased as the oil/water partition coefficient of MP increased. The skin primary irritation increased as the skin permeability of MP increased. In conclusion, we suggest that the skin irritation could be reduced by the decrease of skin permeability of MP, which may be obtained by the good selection of oils in cosmetic preparations.

• Membrane and Water Treatment
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• 제2권1호
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• pp.39-49
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• 2011

We investigated about the utilization improvement of the PDMS and fluoropolymers by mutual application in environmental analysis. We were conducted the direct fluorination with mild condition on the PDMS films and analyzed its surfaces before and after fluorination. The results of FTIR and SEM analysis on the PDMS films showed that the film surfaces were fluorinated without irreversible deformation by the fluorination. During the fluorination, the measured contact angles of water and several alcohols on the PDMS films decreased with time and that of most alcohols decreased to 0 after 30 minutes. The surface energy of fluorinated PDMS films has increased by 2 times. Also, we investigated the influence factors on the change of permeation rate of water through PDMS tubes with time. It was observed that the change of permeation rate of water through PDMS tube was affected by temperature, water phase and spatial distribution of water. From these results, we could verify the principal causes of the decrease of permeation rate of water through PDMS tube with time and proposed a new experimental setup for reducing the variation of permeation rate of water less than 2%.

• Journal of Pharmaceutical Investigation
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• 제29권2호
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• pp.137-143
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• 1999

Ketoprofen together with various permeation enhancers was incorporated into a novel soft hydrogel which is semi-solid in a container and to form a thin film within a few minutes after applying on the skin. The effect of various enhancers on the skin permeation of ketoprofen from a soft hydrogel was investigated using in vitro and in vivo method. In vitro rat skin permeation of ketoprofen from soft hydrogel was conducted using modified Keshary-Chien diffusion cells. In vivo ketoprofen absorption was also investigated in rats, and the results were compared with that of commercial products. Anti-inflammatory activities were determined using carrageenan-induced paw edema method and adjuvant-induced arthritis method in rats. The anti-inflammatory activity of ketoprofen soft hydrogel formulation with that of commercial products were compared. In vitro as well as in vivo studies showed that $HPE-101^{\circledR}$ was the most effective skin permeation enhancer among those used in this study. Addition of an adhesive (polyisobutylene) in the soft hydrogel decreased skin permeation of ketoprofen. Paw edema and anti-arthritis tests showed that soft hydrogel containing $HPE-101^{\circledR}$ was more effective than the commercial products, which was consistent with the in vivo absorption experiment results.

• 한국응용과학기술학회지
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• 제17권1호
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• pp.43-48
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• 2000

Drug delivery system(DDS) applied to various fields, such as medicine, cosmetics, agriculture and necessities of life. Among these application fields, DDS is often used as the method of drug dosage into the epidermic skin. We investigated characters of transdermal therapeutic system(TTS) and the skin permeability of that with applying DDS. Chitosan was selected as material of TTS. We investigated the permeation of chitosan ointment containing drug in rat skin using horizontal membrane cell model. Permeation properties of materials were investigated for water-soluble drug such as riboflavin in vitro. We used glycerin, PEG 600 and oleic acid as enhancers. Since dermis has more content water(hydration) than the stratum corneum, skin permeation rate at steady state was highly influenced when glycerin was used in water-soluble drug. The permeation rate of content enhancer and drug was found to be faster than that of content water-soluble drug only. These results showed that skin permeation rate of drug across the composite was manly dependent on the property of ointment base and drug. Proper selection of the polymeric materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate.

• 공업화학
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• 제7권6호
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• pp.1087-1095
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• 1996

Poly(dimethyl siloxane)막을 이용하여 $45^{\circ}C$에서 에탄올/이소프로판올/물의 삼성분 혼합물에 대한 투과증발실험을 행하고, 에탄올과 이소프로판올의 존재가 상호의 투과특성에 미치는 영향을 연구하였다. 에탄올과 이소프로판올은 각각 상호의 투과속도를 감소시키는 경향을 나타내었으며, 이소프로판올이 에탄올의 투과에 미치는 영향보다는 에탄올이 이소프로판올의 투과에 미치는 영향이 더 현저하였다. 투과속도의 감소는 고분자막에 대한 에탄올이나 이소프로판올의 가소화 영향보다는 투과성분 사이의 상호작용에 의한 영향이 더 크기 때문으로 생각되었다. 삼성분 혼합물에서 투과성분 사이의 강한 상호작용은 에탄올과 이소프로판올의 투과에 대한 추진력을 감소시키는 결과를 나타내었다.

• 멤브레인
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• 제9권1호
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• pp.43-50
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• 1999

폴리설폰 중공사막에 대한 산소와 질소의 투과도에 미치는 수분의 영향에 대한 실험을 수행하였다. 상대습도가 증가할수록 수분을 함유한 산소와 질소의 투과도는 감소하였따. 공급압력 3 kgf/$cm^2$와 온도 3$0^{\circ}C$에서, 상대습도 100% 인 산소의 투과도는 건조산소의 투과도보다 20%만큼 감소하였으며, 질소는 14%만틈 감소하였다. 수분을 gkadmb한 산소의 투과도는 운전시간이 경과함에 따라 단조하게 감소하여 정상상태에 도달하였다. 그러나, 질소의 투과도는 일시적으로 증가하였다가 감소하여 정상상태에 도달하였다.

• 한국세라믹학회지
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• 제50권6호
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• pp.485-488
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• 2013

A SiC-$CeO_2$ composite membrane was successfully fabricated using an ally-hydridopolycarbosilane (AHPCS) binder and treated by dip-coating at 60 times with a $CeO_2$ sol solution. The dip-coated SiC membrane was calcined at 773 K and then sintered at 1173 K under an air atmosphere. The coated membrane was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and a BET surface analysis. The difference in permeation performance between $H_2$ and CO gases was measured by varying the temperature. The permeation flux of $H_2$ on the SiC membrane with layered $CeO_2$ was obtained as $8.45{\times}10^{-6}\;mol/m^2sPa$ at room temperature. The CO permeation flux was $2.64{\times}10^{-6}\;mol/m^2sPa$ at room temperature. The reaction enthalpy (${\Delta}H^{\circ}$) for the hydrogen permeation process was calculated as -7.82 J/mol by Arrhenius plots.