• Bulletin of the Korean Chemical Society
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• 제20권7호
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• pp.796-800
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• 1999

Three anthrylazacrown ethers in which the anthracene fluorophore π system is separated from the electron donor atoms by one methylene group were synthesized, and their photophysical study was accomplished. These fluorescent compounds showed a maximum fluorescence intensity at pH=5 in aqueous solutions and a decrease in fluorescence intensity upon binding of paramagnetic metal cations (Mn 2+ (d 5 ), Co 2+ (d 7 ), Cu 2+ (d 9 )). The decrease in fluorescence intensity may be attributed to the paramagnetic effect of metal cations to deactivate the excited state by the nonradiative quenching process. The benzylic nitrogen was found to play an important role in changing fluorescence intensity. From the observed linear Stern-Volmer plot and the fluorescence lifetime independence of the presence of metal ions, it was inferred that the chelation enhanced fluorescence quenching (CHEQ) mechanism in the system is a ground state static quenching process. Enhanced fluorescence was also observed when an excess Na + ion was added to the quenched aqueous solution, and it was attributed to cation displacement of a complexed fluorescence quencher.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 추계총회,초청강연,특별강연,연구발표회
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• pp.98.2-98
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• 2000

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.417-418
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• 2018

• 한국염색가공학회지
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• 제16권4호
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• pp.10-18
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• 2004

In this work, Aqueous sericin solution was prepared by degumming process with electrolytic reduction water. Then, the microfiltration and ultrafiltration systems were applied to the concentration of aqueous sericin solution. The objective of this study was to select the optimum operating condition among the different pressure. The permeate flux and rejection ratio were observed with time, pressure, flow rate and concentration. and, the wastewater and permeated water quality values such as pH, BOD, COD, and NH levels were measured. In order to see the influence of electrolytic reduction water, the flux of pure water and electrolytic reduction water by PVDF22(MF) and PS100(UF) membrane was measured. In microfiltration system, the relative flux reduction decreased rapidly to 0.02 in the 30min, as the concentration polarization and gel layer formation were increased. and then the sericin concentration rejection ratio was 40%. In ultrafiltration system, the permeate flux decreased with time and concentration, and increased with the operating pressure and flow rate. Optimal condition in PS100 membrane system for sericin concentration was operating pressure 1.464kgf/$cm^24, operating flow rate $7\ell/min at\; 40^{\circ}C$. At that time, sericin concentration rejection ratio was 83% respectably. The sericin solution was concentrated from 0.1wt% solution to 0.2 wt % solution during about 2 hrs by the UF filteration membrane system.

• Journal of Biosystems Engineering
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• 제24권4호
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• pp.317-324
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• 1999

This study was conducted to decide several design criterion for clean-washed rice processing system development. A Computer simulation was used to predict and analyze the mass balances and moisture changes of the process of clean-washed rice processing system. The following results were obtained from this study. 1. In order to attain the processing capacity of 1,000kg/h of the clean-washed rice processing system, that of the system was designed as 1,400kg/h which was based on the safety factor of 40% and handling capability of mass variations occurred during processing. 2. It was analyzed that the proper time required for aqueous cleaning process should be within one minute. 2. It was analyzed that the proper time required for aqueous cleaning process should be within one minute. 3. The final moisture content of clean-washed rice was controlled being 15%(w.b.) for the sake of safe storage. 4. It was proven that the optimum drying time was three minutes for the clean-washed rice dried by a rotary dryer.

• 한국염색가공학회지
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• 제17권4호
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• pp.21-26
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• 2005

A combination separation system is composed of three parts, simple microfiltration unit for the pretreatment of real waste IPA, pervaporation unit with plate and frame type module(the effective membrane area 9,040$cm^2$), and simple ultrafiltration unit as a refiner. Utrafiltration module with hollow fiber membrane(MWCO 10,000) used to purify waste aqueous IPA solution. In addition, the flux of $CMPA-K^+$ composite membrane for waste aqueous IPA solution was very steady-state with long experiment time(30 days). And the standard deviation($\sigma$) was 0.152 and then the coefficient of variation($CV\%$)was 10.82 The IPA concentration on the membrane performance using pervaporation module system could be increased from $89.85wt(\%)$ to more than $99.90wt\%$ in about 8hr at operation temperature of $70^{\circ}C$ using the pervaporation module system. Therefore, a combination separation process system of simple filtration and pervaporation was very effective for the purpose of the IPA purification and reuse front industrial electronic components cleaning process.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.283-286
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• 2002

Solubilization and partitioning of naphthalene was investigated in an aqueous system containing soils and surfactants. The environmental behavior of polycyclic aromatic hydrocarbons(PAHs) was mainly governed by their solubility and partitioning properties on soil media in a subsurface system. In surfactant-enhanced remediation systems, surfactants might be an additional variable. a natural soil ,silica and kaolinite were tested as soil media. two nonionic surfactants, Triton X-100 and Hydropropy1-$\beta$-cyclodextrin (HPCD) were employed for naphthalene solubilization. Naphthalene showed linear on natural soil while non-linear sorption on silica and kaolinite. Soils have higher sorption capacity for Triton X-100 than HPCD indicating Triton X-100 formed ad-micelle on the soil surface. Desorption study showed a hysterysis and reversible desorption. The partitioning coefficient(K$_{D}$) of naphthalene was increased as the concentration of surfactant was increased. (below CMC), however, the coefficient was decreased above CMC. This indicates that naphthalene is partitioned into the micelles and the partition occurs competitively on both ad-micelle and free micelles as surfactant concentration increases. Therefore, the target compounds to be dissolved into aqueous phase in a surfactant enhanced remediation system might be highly partitioned on to the ad-micelle resulting in an adverse effect rather increased solubilization would be achieved.d.

• 설비공학논문집
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• 제22권7호
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• pp.419-428
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• 2010

This paper presents the optimization process of liquid desiccant cooling system using LiCl aqueous solution as a working fluid. Operating conditions(mass flow rate, conditioner outlet concentration, difference concentration) and design factors for heat exchangers(difference temperature of the district heating water, leaving temperature difference of the conditioner, leaving temperature difference of the regenerator, air temperature difference of the conditioner, air temperature difference of the regenerator) were optimized by response surface method. As a result, we obtained the 7.297 kW of cooling capacity and 0.788 of COP at optimized condition. Effect of difference temperature of hot water on system performances was also examined. As difference temperature of the district heating water increases, the cooling capacity increases and COP decreases.

• 한국식품과학회지
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• 제19권2호
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• pp.146-150
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• 1987

폴리에틸렌 글라이콜(PEG)-텍스트란 수용액 혼합물이 형성 하는 2상계에서 단백질의 분획현상에 대한 pH와 금속 이온의 영향을 검토하였다. PEG(5%)/dextran(9.5%)을 포함하는 5mM 인산 완충용액으로된 수용액 2상계에서 상층부와 하층부의 용적비를 1.0으로 하였을 때 분획계수는 각 단백질들의 등전점에서최소치를 나타 내었으며, pH가 등전점에서 벗어날 수록 단백질 분획계수는 증가하였다. 특히 pH11.0에서는 분획계수가 크게 증가하였으며 소수성이 가장 큰 BSA는 50배 ${\beta}-lactoglobulin$과 소수성이 비교적 적은 ovalbum은 각각 10배 증가하였다. 금속염 첨가는 pH3.0에서 단백질과 분획계수를 증가시키나. pH7.0과 pH11.0에서는 급격하게 감소시켰다. 단백질의 총전하가 양전하를 띠게 되는 pH3.0에서는 LiNa>K의 순으로 분획계수는 감소하였다.

• KSBB Journal
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• 제22권4호
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• pp.207-212
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• 2007

본 연구에서는 수성이상계에서 Pluronic F-68과 산소전달물질을 적용하여, 물질전달과 산소전달을 증가시켜 당귀세포의 증식을 향상시켰다. 특히 산소전달물질인 n-hexadecane이 Pluronic F-68보다 수성이상계에서의 당귀 세포증식에 더 긍정적임을 확인하였다. 따라서 Pluronic F-68과 적절한 산소 전달물질의 첨가는 수성이상계 뿐만 아니라 대량배양을 위한 고농도배양 등에 효과적으로 적용가능하리라 사료된다.