• KSBB Journal
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• 제15권4호
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• pp.342-345
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• 2000

식물세포배양으로부터 peroxidase를 대량 생산하기 위한 분리/정제 공정 으로서 세포를 파쇄하고 크로마토그래피 전처리로서 활성백토를 적용하였다. 활성백토는 미세한 세 포 조각 뿐만 아니라 여려가지 불순불을 선택적으로 흡착 하는 성질을 나타내었으며, 이를 통하여 효과적으로 정제 공정을 진행할 수 있었다 흡착을 통한 전처리 후 한외여 과장치를 이용하여 농축을 실시 하였으며, DEAE-Sepharose F FF를 이용한 크로마토그래피를 통해 정제가 이루어졌다. 활성을 나타내는 용액을 탈염, 농축 후 동결 건조하였다. 이 공정은 상업화에 필요한 대량 정제를 가능하게 하였으며 수율과 정제비용 측면에서 상당히 경제적인 공정임을 입증하였다, 활성백토를 이용한 흡착공정은 다른 효소 및 단백질의 경제적인 대량정제에 적용될 수 있으리라 기대된다.

• 대한핵의학회지
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• 제23권1호
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• pp.63-69
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• 1989

In order to develop technetium-99m-labelled human albumin microsphere (HAM) for lung scintigraphy, various experimemts such as preparation and fractionation of HAM, establishment of optimal labelling conditions, determination of radiochemical purity, stability test and biodistribution of $^{99m}Tc-HAM$ were carried out. HAM was prepared from the suspension of 1ml aqueous human serum albumin (25%) in 130 ml of olive oil at $130\sim135^{\circ}$ with vigorous stirring. The resulting HAM was fractionated with microsieve to get the desired particle size $(15\sim50\mu)$ and autoclaved for sterilizaiton. The HAM particles were treated with stannous chloride and the pH of the suspension was adjusted to $3.0\sim3.5$ with phosphate buffer. After freeze-drying the contents of single reaction vial containing 5 mg of HAM and 0.2 mg of $SnCl_2$ it was reacted with $Na^{99m}TcO_4$. The labelling yield was higher than 99.5% and the stability of $^{99m}Tc-HAM$ was high enough to maintain 99.1% of radiochemical purity up to 24 hours. Lung and liver uptake in mice was found to be 94% and 0.9%, respectively. Excellent rabbit and human lung scans were also obtained.

• 공업화학
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• 제26권5호
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• pp.621-623
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• 2015

본 연구는 Dimethyl terephtalate (DMT) 제조 공정에서 발생하는 반응 부산물로부터 고순도의 Methyl 4-formylbenzoate (MFB)를 정제하는 방법에 관한 내용이다. 반응 부산물에 포함된 MFB의 알데하이드 작용기와 메탄올을 반응시켜 아세탈 화합물로 전환하여 분리하고, 연속적으로 산 촉매 하에 가수분해하여 90% 수율로 MFB를 얻을 수 있었다. 얻어진 MFB는 $^1H$ NMR 및 $^{13}C$ NMR로 구조를 확인하였으며 또한 GC 분석을 통해서 99% 이상의 순도를 확인하였다.

• 한국정밀공학회지
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• 제23권1호
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• pp.80-88
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• 2006

In this study, unsintered and presintered low purity alumina ceramics were machined with various tools to clarify the machinability and the optimum cutting conditions. The main conclusions obtained were as fellows. Machined with ceramic tool, the ceramics presintered at the temperature range of $1000\~1100^{\circ}C$ showed the best machinability due to the adhesion formed in weared surface within a certain cutting speed range. In the above combination and conditions, the ceramic tool showed the highest productivity through all experiments. The life of CBN tool was longer in machining of the ceramics presintered at $1000^{\circ}C$ than in the case of that presintered at $600^{\circ}C$, but the diamond tool showed adverse tendency. In machining of the ceramics presintered at $1000^{\circ}C$, the ceramic tool exhibits the longest tool life in high speed, the tool lives became extremely worse in the order of CBN tool and diamond tool. However, in the case of the ceramics presintered at $600^{\circ}C$, the diamond tool shows the longest tool life, the tool lives was much worse in the order of CBN tool and ceramic tool.

• 한국전산유체공학회지
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• 제16권4호
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• pp.110-115
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• 2011

A modern optical fiber manufacturing process requires the sufficient cooling of glass fibers freshly drawn from the heated and softened silica preform in the furnace, since the inadequately cooled glass fibers are known to cause improper polymer resin coating on the fiber surface and to adversely affect the product quality of optical fibers. In order to greatly enhance the fiber cooling effectiveness at increasingly high fiber drawing speed, it is necessary to use a dedicated glass fiber cooling unit with helium gas injection between glass fiber drawing and coating processes. The present numerical study features a series of three-dimensional flow and heat transfer computations on the cooling gas and the fast moving glass fiber to analyze the cooling performance of glass fiber cooling unit, in which the helium is supplied through the discretely located rectangular injection holes. The air entrainment into the cooling unit at the fiber inlet is also included in the computational model and it is found to be critical in determining the helium purity in the cooling gas and the cooling effectiveness on glass fiber. The effects of fiber drawing speed and helium injection rate on the helium purity decrease by air entrainment and the glass fiber cooling are also investigated and discussed.

• Journal of Ginseng Research
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• 제40권2호
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• pp.121-126
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• 2016

Background: Ginsenoside F1, a pharmaceutical component of ginseng, is known to have antiaging, antioxidant, anticancer, and keratinocyte protective effects. However, the usage of ginsenoside F1 is restricted owing to the small amount found in Korean ginseng. Methods: To enhance the production of ginsenoside F1 as a 10 g unit with high specificity, yield, and purity, an enzymatic bioconversion method was developed to adopt the commercial enzyme Cellulase KN from Aspergillus niger with food grade, which has ginsenoside-transforming ability. The proposed optimum reaction conditions of Cellulase KN were pH 5.0 and $50^{\circ}C$. Results: Cellulase KN could effectively transform the ginsenosides Re and Rg1 into F1. A scaled-up biotransformation reaction was performed in a 10 L jar fermenter at pH 5.0 and $50^{\circ}C$ for 48 h with protopanaxatriol-type ginsenoside mixture (at a concentration of 10 mg/mL) from ginseng roots. Finally, 13.0 g of F1 was produced from 50 g of protopanaxatriol-type ginsenoside mixture with $91.5{\pm}1.1%$ chromatographic purity. Conclusion: The results suggest that this enzymatic method could be exploited usefully for the preparation of ginsenoside F1 to be used in cosmetic, functional food, and pharmaceutical industries.

• 디자인학연구
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• 제15권2호
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• pp.169-176
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• 2002

본 연구의 목적은 디자인경영 개념을 도입하여 플라스틱 소재를 중심으로 휴대용 전자기기 소재에 나타난 칼라 트렌드를 우리나라와 일본지역 실지조사를 통해서 칼라 트렌드의 현황및 예측하는데 있다. 경영의 개념을 디자인에 결합, 도입시킴으로서 우리나라 기업들이 보다 더 합리적이고 체계적인 디자인 프로세스 관리에 대한 사고의 전환을 시도하였고, 또한 디자인 지식공유시스템을 통한 중소기업, 가전업체, 전문기관 및 관련단체와의 지식 공유화 방안을 제시하고자 하였다. 플라스틱 소재에 나타난 칼라 트렌드 조사 결과, Cybertic, Purity 및 Colorful 경향 등 3가지 경향을 보여주고 있으며, 감성마케팅 전략으로서의 칼라 및 표면처리 추진방향은 고급화, 다양화, 그리고 차별화 등에 초점을 두고 있는 것으로 나타났다. 마지막으로, 칼라 트렌드 DB 구축방안을 제시하였다.

• 한국응용과학기술학회지
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• 제30권1호
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• pp.57-63
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• 2013

Ammonium dinitramide (AND) is one of the most promising oxidizers in propellants without chlorinated pollution to the atmosphere in these days. Potassium sulfamate (PS) is a key substance in ADN synthesis as forming nitrates such as $-N(NO_2)_2$. In this paper, potassium sulfamate as a starting material for ADN synthesis was prepared in a lab scale through crystallization with ethanol solvent, and observed the effects on the yield and purity of KDN. The prepared potassium sulfamates were analyzed using FE-SEM, XRD, BET and TGA-DSC. The lab-made PS, which was ground to $20{\mu}m$ showed more beneficial than a commercial product achieving high yield and purity of the synthesized KDN. It would be associated closely with crystallinity, porosity and pore size of prepared PS.

• 세라미스트
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• 제22권4호
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• pp.452-463
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• 2019

A quartz glass crucible is the essential material for manufacturing silicon ingots such as semiconductors and solar cells. Quartz glass crucibles for semiconductors and solar cells are made similar, but differ in surface purity, structure and durability. Recently, ultra high purity synthetic glass crucibles for semiconductors have become more important due to foreign problems. In Korea, it has succeeded in producing 28-inch quartz glass crucibles through the past 10 years. However, 32-inch synthetic quartz glass for the production of silicon ingots for semiconductors is not up to the level of advanced technology, and the technology gap is expected to be 2 to 3 years. In order to overcome these technological gaps and localize synthetic quartz glass ware, close cooperation between production companies and demand companies and localization of synthetic quartz glass powder must also be made. In addition, if government support can be added, faster results can be expected.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2299-2302
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• 2009

By controlling the number of electrons transferred to the emitting layer, highly efficient three-wavelength WOLEDs were fabricated. Such WOLEDs are different from those made using simple stacking of RGB emitting layers in that the movement distribution of electrons transferred to emitting layer could be adjusted using the difference in LUMO energy level and that lights of all 3 wavelengths could be emitted through appropriate arrangement of RGB emitting layers. WOLED device with the structure of m-MTDTA (40 nm)/NPB (10 nm)/ Coumarin6 doped $Alq_3$ (3%) (8 nm)/ Rubrene doped NPB (5%) (15 nm)/NPB (2 nm)/ DPVBi (20 nm)/$Alq_3$ (20 nm)/LiF (1 nm)/Al (200 nm) showed high luminance efficiency of 8.9 cd/A and color purity of (0.31, 0.40). In addition, WOLED device with the thickness of non-doped NPB layer increased from 2 nm to 3 nm to increase blue light emission showed a luminance efficiency of 7.6 cd/A and color purity of (0.28, 0.36).