• 공업화학
• /
• 제19권1호
• /
• pp.105-110
• /
• 2008

증류-추출의 조합에 의해 접촉분해경유(LCO)로부터 회수한 dimethylnaphthalene (DMN) 이성체 농축액을 원료로 사용하여 결정화조작을 행해 2,6-DMN의 정제를 검토했다. 2,6-DMN의 정제에 적합한 용매의 선정을 위해 13종의 용매(acetone, cyclohexanone, ethanol, ethyl ether, ethyl acetate, isopropyl ether, methanol, n-hexane, n-heptane, pyridine, THF, toluene, methanol과 acetone의 혼합용매)를 사용하여 결정화조작을 행한 결과, 60 vol% methanol과 40 vol% acetone의 혼합용매(M/A = 1.5)가 2,6-DMN의 순도 및 수율의 측면에서 우수한 정제성능을 보였다. 결정화 온도의 상승 및 용매(M/A = 1.5)/원료(농축액)의 체적비의 증가는 2,6-DMN의 순도를 향상시켰으나, 역으로 수율의 저하를 초래시켰다. DMN 이성체 농축액을 원료(10.43 wt% 2,6-DMN)로 사용한 결정화를 통해 회수한 결정(76 wt% 2,6-DMN)을 원료로 사용하여 재차 결정화조작을 행한 결과, 40%의 수율로 99.7 wt% 2,6-DMN의 결정을 얻을 수 있었다.

• Journal of Microbiology and Biotechnology
• /
• 제9권4호
• /
• pp.386-392
• /
• 1999

A large-scale culture of hepatitis A virus in human diploid MRC-5 cells was conducted. In a roller bottle culture, the virus was grown to a maximum titer in 3 weeks after infection. Over 95％ of the cell-associated virus was excreted after culturing the infected cells in suspension media without fetal bovine serum for 3 days. The cultured virus was inactivated with formalin, concentrated by ultrafiltration, and partially purified by ultracentrifugation in a non-ionic gradient medium of Renocal. Two separate peak fractions showing high anti-HAY ELISA titer were pooled and about 40％ of HAV antigen was recovered by this purification procedure. Of the partially purified vaccine, the protein pattern in SDS-PAGE and immunogenicity in mice were compared with a commercial HAV vaccine. In SDS-PAGE, the purified vaccine in this study and the commercial vaccine showed almost the same protein pattern. The seroconversion rate of the purified vaccine in mice was not different from that of the commercial vaccine. Therefore, we could prepare a good grade of HAV vaccine by a simple purification procedure although the purification itself was not completed.

• 조명전기설비학회논문지
• /
• 제29권3호
• /
• pp.54-60
• /
• 2015

There are 5 purification plants with the adopted advanced water purification treatment process in Korea. Annual operating costs were 8,990 million won including purchase cost of oxygen and power usage charges. We need research to optimize, in the future, when considering the direction of domestic water treatment continues to adopt advanced water treatment process. In this paper, calculate the optimal operating costs by injected the oxygen gas, used power cost. approximately 25% of the operating costs can be reduced when injected the ozone gas is 1.0ppm than 2.0ppm, the necessary amount of oxygen is increased then power is lower. so operating costs are decided according to oxygen costs. On the other hand, high ozone concentration 2.0ppm, the necessary power is increased then amount of oxygen is lower. Therefore, in the case of G purification plant, the controlling factor of the input ozone concentration 2ppm, PID control operation by setting the concentration of over 10Wt% is efficient. The installed capacity is the more little the more better when considering on Ozone injection rate in the process of water treatment.

• Journal of Microbiology and Biotechnology
• /
• 제27권1호
• /
• pp.84-91
• /
• 2017

The concern over the use of melittin in honey bee venom due to its adverse reaction caused by allergens such as phospholipase A2 ($PLA_2$) and hyaluronidase (HYA) has been an obstacle towards its usage. We developed a novel single-step method for melittin purification and the removal of $PLA_2$ and HYA. This study explores the influence of pH, buffer compositions, salt concentration, and types of cation-exchange chromatography resins on the recovery of melittin and the removal of both HYA and $PLA_2$. Melittin was readily purified with a strong cation-exchange resin at pH 6.0 with sodium phosphate buffer. It resulted in a recovery yield of melittin up to 93% (5.87 mg from a total of 6.32 mg of initial melittin in crude bee venom), which is higher than any previously reported studies on melittin purification. $PLA_2$ (99%) and HYA (96%) were also successfully removed. Our study generates a single-step purification method for melittin with a high removal rate of $PLA_2$ and HYA, enabling melittin to be fully utilized for its therapeutic purposes.

• 환경영향평가
• /
• 제14권4호
• /
• pp.147-155
• /
• 2005

This study was designed to investigate the effect of plant as a botanical air purification on the indoor pollution by formaldehyde. Three indoor plants such as Dracaena marhginata, Spathiphyllum and Dracaena reflexa, were placed in the artificially contaminated reactor under laboratory condition. Both plant and soil effects on removal of formaldehyde from contaminated indoor air were observed. Reductions in the formaldehyde levels appeared to have been associated with soil medium factors as well as plant factors. The effect of soil on formaldehyde reduction was high in the early stage of the experiment and the results suggest that sorption could be more important factor than microbial degradation in the initial dissipation of contaminants in the soil. It was suggested that the effect of plant on formaldehyde reduction might be related to the plant species, total leaf surface area of plant, degree of contribution of soil medium, and exposed concentration level. The results of this study showed that air purification using plants is an effective means of reduction on indoor formaldehyde level, though, utilization of soil media with high sorption capacity and/or supplementary purifying aids were also suggested when the source is continuous or exposed concentration level is high.

• 대한방사성의약품학회지
• /
• 제6권2호
• /
• pp.69-74
• /
• 2020

PIB is the first amyloid plaque PET image tracer reported for the first time in 2003, and is considered to be the best and is still being utilized due to its very high uptake and kinetic properties. Initially, it was synthesized by radioisotope labeling using a precursor containing a methoxy methyl protection group, but now it is synthesized using a 6-OH precursor that can be easily synthesized in one step using [¹¹C]methyl triflate. Carbon-11 has several limitations in clinical studies using PET because its half-life is as short as 20 minutes. In this study, in order to overcome the difficulty of this half-life, a rapid method using Sep-Pak was adopted instead of HPLC purification to significantly reduce the burden of the purification process and attempted synthesis. As a result, the synthesis time was shortened by more than 50%, and the yield of the final compound was higher than the previous result and showed relatively high specific radioactivity, confirming that it is a strategic method with high applicability for various precursors having primary amines.

• 한국주조공학회지
• /
• 제12권3호
• /
• pp.220-229
• /
• 1992

The degree of purification and the macrostructure of high purity aluminium were studied through the alternate stirring method in order to improve the nonuniformity of solute concentration in the unidirectional stirring method. The $2^3$ factorial design was done to examine the effects of experimental factors more qualitatively. In the relatively low stirring speed of 1500 rpm with alternate stirring mode, the uniform solute profile and refined grain structure were obtained due to strong washing effect and turbulent fluid flow. It was induced by the transition of the momentum boundary layer by alternation of the stirrer. It was concluded from this study that the alternate stirring mode was more effective to obtain the uniformity of solute even in the stirring speed of 1500 rpm. But the degree of purification decreased below the critical alternating period. When 2N(99.8wt.%) aluminium was used as the starting material the morphology of solid-liquid showed the cellular shape and the columnar grains were inclined to the direction of rotation. This inclined grain growth resulted from the difference of relative velocities of solid and liquid. The inclined angle was increased as the stirring speed increased and solidification proceeded. In the case of 4N aluminium, there was no inclined grain growth and it was confirmed from the macrostructure and SEM work that the morphology of solid-liquid interface was planar. From the factorial design, it was found that the alternate stirring mode showed poorer purification effect than that of unidirectional stirring mode at low speed(500 rpm). In addition, the factor that had the most significant effect on the degree of purification was the stirring speed.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.383-383
• /
• 2009

Silicon is commercially prepared by the reaction of high-purity silica with wood, charcoal, and coal, in an electric arc furnace using carbon electrodes, so called the metallurgical refining process, which produces ~98% pure Si (MG-Si). This can be further purified to solar grade silicon (SoG-Si) by various techniques. The most problematic impurity elements are B and P because of their high segregation coefficients. In this study, we explored the possibility of the using Cat-CVD for Si purification. The existing hot-wire CVD was modified to accommodate the catalyzer and the heating source. Mo boat (1.5 cm ${\times}$ 1 cm ${\times}$ 0.2 cm) was used as a heating source. Commercially available Si was purchased from Nilaco corporation (~99% pure). This powder was kept in the Mo-boat and heated to the purification temperature. In addition to the purification by cat-CVD technique, other methods such as thermal CVD, plasma enhanced CVD, vacuum annealing was also tried. It is found that the impurities are reduced to a great extent when treated with cat-CVD method.

• 한국광물학회지
• /
• 제19권1호통권47호
• /
• pp.1-5
• /
• 2006

본 연구에서는 $0.1{\sim}0.3mm$ 입도의 규석을 대상으로 물리적 선별공정을 적용하였을 때의 정제효과를 조사하였다. $SiO_2$ 품위가 99.41 wt.%, 99.54 wt.%이고 불순물 함량이 각각 5,864 mg/kg과 4,568 mg/kg인 시료에 대하여 자력선별, 비중선별 및 scrubbing 공정을 단계별로 적용시킨 결과, 주요 불순물인 철 성분은 자력선별에 의하여, 알루미늄 성분은 비중선별에 의해 효과적으로 제거되었다. 최종 정제산물의 $SiO_2$ 품위는 99.98 wt.%였으며, 산출율은 각각 79.05 wt.%와 75.43 wt.%였다. 이때 불순물의 함유량은 각각 126 mg/kg, 174 mg/kg을 나타내어, 불순물의 제거율은 97.85wt.%, 96.19 wt.%였다. 따라서 물리적 분리 선별에 의하여 저급 품위(Low grade)의 규석을 불순물 함유량이 200 mg/kg 이하인 중 고급 품위(Medium-high grade) 이상으로의 품위 향상이 가능하였다.

• 한국농공학회논문집
• /
• 제53권2호
• /
• pp.75-82
• /
• 2011

This study was performed to evaluate the water purification properties of bio-composites planting blocks using oyster shell and effective microorganism that have high absorption ability of heavy metals and organics to develop environmentally friendly river embankment technique contained various factors such as oyster shells, effective microorganism, porous concrete and planting embankment block. To maximize greening effect, the seeds were arbitrarily sown. In addition, in order to analyze the effect of water quality purification after the planting, the samples were collected from each designated zone 1, 7 and 30 days after steeping in water. Then, the samples were analyzed in terms of seven test items such as SS, BOD, COD, T-N, T-P, pH, etc. on the basis of the test method for water pollution. The following conclusions were reached from the test result. As a result of analysis for water quality purification for the concrete block containing the effective microorganism, it was found that the values for SS, BOD, T-N and T-P for the sample taken after 30 days were lower than the initial values, which indicated that the water purification effect had been created. The result of the water quality purification analysis for the concrete block containing oyster shell showed that the values for SS, BOD, COD and T-P for the sample taken after 30 days were lower than the initial values which also indicated that it had been effective in water quality purification.