• 멤브레인
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• 제19권2호
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• pp.145-149
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• 2009

본 연구의 목적은 나노복합막을 제조하여 가수분해된 세리신 용액에 함유되어 있는 염의 제거 거동을 살펴보는 것이다. 계면중합법으로 나노복합막을 제조하고 상용화되어 있는 나노복합막과 탈염 거동을 비교하였다. 세리신 용액은 단백질 분해효소에 의해서 분해하여 저분자화하였고 전기영동에 의해 분자량 분포를 살펴보았다. 상대투과유량을 조사하여 나노복합막의 막오염 정도를 살펴보았다. 기공크기가 큰 나노복합막이 탈염에 효율적인 것을 확인하였다.

• Current Photovoltaic Research
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• 제7권2호
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• pp.33-37
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• 2019

In this paper, we compared the performance of $Cu(In,Ga)(S,Se)_2$ (CIGSSe) thin film solar cell with CdS buffer layer deposited by irradiating 365 nm UV light with 8 W power in Chemcial Bath Deposition (CBD) process. The effects of UV light irradiation on the thin film deposition mechanism during CBD-CdS thin film deposition were investigated through chemical and electro-optical studies. If the UV light is irradiated during the solution process, the hydrolysis of Thiourea is promoted even during the same time, thereby inhibiting the formation of the intermediate products developed in the reaction pathway and decreasing the pH of the solution. As a result, it is suggested that the efficiency of the CdS/CIGSSe solar cell is increased because the ratio of the S element in the CdS thin film increases and the proportion of the O element decreases. This is a very simple and effective approach to control the S/O ratio of the CdS thin film by the CBD process without artificially controlling the process temperature, solution pH or concentration.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.183-186
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• 1998

This paper deals with 28, 56, 91 days age compressive strength and ratio of weight when OPC and Low-Heat cement mortar immersed in chemical solution. As a result of experiment, the resistance of Low-Heat Cement motar in chemical attack is more effective than that of OPC, because of lower $C_3$A content and Pozzolanic reactions. Especially in long term age compressive strength, Low-Heat cement mortar shows higher strength in all kind of chemical solution compared with compressive strength of OPC motar.

• 대한화학회지
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• 제15권5호
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• pp.223-228
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• 1971

In the electrolytic preparation of persulphate from sulphate solution, the current efficiency decrease with temperature increase at the platinum anode. But in case of electrodeposited lead peroxide anode, the current efficiency increase with temperature of the solution. The reason seems to be that the ozone formation is faster in platinum anode than in lead peroxide as temperature increase.

• 한국재료학회지
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• 제16권2호
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• pp.123-128
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• 2006

[ $BaMgAl_{10}O_{19}:Mn^{2+}$ ](BAM:Mn) phosphor particles with spherical shape were prepared by spray pyrolysis from colloidal solution with silica. The phosphor particles prepared by spray pyrolysis from aqueous solution had irregular morphology after high temperature post-treatment. On the other hand, the phosphor particles prepared from spray solution with colloidal silica had spherical shape after post-treatment. Colloidal silica used as additive improved the spherical shape and filled morphology of the precursor particles prepared by spray pyrolysis. The precursor particles with filled structure produced the BAM:Mn phosphor particles with spherical shape and non-aggregation characteristics after post-treatment at $1400^{\circ}C$ under reducing atmosphere. The phosphor particles prepared from colloidal solutions formed the crystal structure of BAM:Mn phosphor irrespective of the silica contents. The BAM:Mn phosphor particles prepared from aqueous and colloidal solutions had similar photoluminescence intensities under vacuum ultraviolet.

• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 The 4th Korea-Italy Workshop
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• pp.107-114
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• 2003

This study investigated the effect of 2-methoxy ethanol (2-Me) non-solvent as additive included in casting solution. Macroporous polymer membranes were prepared by using polyethersufone (PES)/N-methyl-2-pyrrolidone (NMP)/2-Me casting solution and water coagulant. The phase separation co-process of the vapor-induced phase separation (VIPS) and liquid-induced phase separation (LIPS) were used by means of membrane preparation method. The pore size and pore size distribution were controlled with additive (non-solvent), and measured with Automated Perm Porometer. By increasing additive (non-solvent) in the casting solution, the membranes produced changed from finger structure to sponge structure. That is due to the different diffusion rates. At slow diffusion process, sponge-like structure was formed and at fast diffusion process, finger-like structure was formed. Also relative humidity, evaporation time, temperature of casting solution and coagulation bath etc. had effects on the pore size distribution and the porosity of the membrane.

• Journal of Pharmaceutical Investigation
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• 제34권4호
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• pp.305-310
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• 2004

This study was to prepare the anionic liposomes which were to release anticancer drug (doxorubicin) at the hyperthermia temperature $({\sim}42^{\circ}C)$ and to stabilize in bovine serum solution at $37^{\circ}C$. The vesicle size and zeta potential of liposomes in Tris-HCl buffered solution (pH 7.4) were measured by an electrophoretic light scattering spectrophotometer. To estimate the stability of liposomes, liposome size was measured in bovine serum solution at $37^{\circ}C$ for 72 h. The release of doxorubicin from liposome was determined by measuring the fluorescence intensity using fluorescence spectrophotometry with temperature and time. The size of liposomes was from 120 to 160 nm and zeta potential was from $-33.3{\pm}2.4$ to $-75.6{\pm}6.9\;mV$. Anionic liposome was stabilized in bovine serum solution at $37^{\circ}C$ within 72 h. Additionally, the release transition temperature of doxorubicin from liposomes was increased by increasing mole % of anionic phospholipid.

• 한국응용과학기술학회지
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• 제25권2호
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• pp.232-239
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• 2008

Separation of naphthalene from naphthalene and 2-methylnaphthalene mixture has been studied by layered melt and solution crystallization using ethylalcohol. Purity and yield of naphthalene depended mainly on the cooling rate: The effective distribution coefficient ($K_{eff}$) as the degree of impurity removal was observed to decrease with the decreasing in cooling rate. Purity of naphthalene can be enhanced to $5{\sim}7%$ by melt crystallization using 90% naphthalene and the purity of naphthalene can be obtained to be 99% up by solution crystallization.

• Korean Chemical Engineering Research
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• 제47권2호
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• pp.157-162
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• 2009

본 논문은 소량 다품종 생산체계로 생산되는 정밀화학제품인 고품질 염료제조를 위한 고효율 염료결정화 분리기술에 대한 연구로써 염료 염석결정화계에서 염료의 물성과 최적조업조건에 대해 연구하였다. 먼저 염료의 물리적 특성을 알아보기 위해 밀도, 점도 등을 다양한 조건하에 측정하였다. 염료의 밀도는 물과 비슷한 특성을 보였으며, 염료 용액의 농도가 변화할 때, 밀도 변화는 거의 없었으며, 점도는 농도가 증가 할수록 증가했다. 염료 용액의 온도가 높아짐에 따라 밀도는 증가하였으나, 점도는 감소하였다. 또 염료의 용해도 실험 결과 20 wt% 염료 용액에 15 wt% KCl을 첨가하였을 때 염료결정의 생성량이 최대로 나타났다. 또한, 최적의 조업조건을 찾기 위해 다양한 변수(온도, RPM, 염첨가 방법 등)를 제어하여 시간에 따라 실험하였다. 15 wt% KCl과 20 wt% 염료용액으로 실험한 결과 최적의 조업조건은 $25^{\circ}C$, 100 RPM, 염을 한 번에 넣는 방법으로 나타났다. 또 최적 조업조건으로 실험을 수행한 결과 기존의 공정($35^{\circ}C$, 150 RPM)보다 생성량이 증가하였다. 따라서 최적화 공정을 찾음으로써 생성량 증가와 에너지 저감 효과가 기대된다.

• Korean Chemical Engineering Research
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• 제46권6호
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• pp.1052-1056
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• 2008

소다 공정에서 탄산칼슘 결정의 평균입경과 형상 변화를 온도변화와 PAA 용액의 첨가에 대하여 연구하였다. 낮은온도($30^{\circ}C$, $60^{\circ}C$)에서는 Calcite 결정을, 높은 온도($80^{\circ}C$)에서는 Aragonite 결정을 얻었다. $30^{\circ}C$와 $80^{\circ}C$에서 용액에 PAA 용액을 첨가하여도 결정의 형상변화는 없었다. 중간온도($60^{\circ}C$)에서 PAA 용액을 첨가하여 Aragonite 결정을 얻었다. 결정의 형상변화가 PAA 분자 첨가로 인하여 일어났다. PAA 용액의 농도가 높을수록, 더 많은 Aragonite 결정을 얻었다. PAA 수용액의 농도가 높고 분자량이 클수록 탄산칼슘 결정의 평균입경은 증대하였으며, 형상변화가 일어나는 영역에서는 PAA의 분자량이 평균입경변화에 중요한 변수가 된다.