• KSBB Journal
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• v.15 no.4
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• pp.342-345
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• 2000

A novel pre-purification method was developed for producing peroxidase to guarantee high purity and yield from plant cell cultures in large-scale process. This method was a simple and efficient procedure for the isolation and pre-purification of peroxidase from the biomass consisting of active clay treatment followed by cationic exchange chromatography. The use of active clay in the pre-purification process allows for rapid and efficient separation of peroxidase from interfering compounds and dramatically increases yield and purity of crude peroxidase for purification steps compared to alternative processes. This pre-purification process serves to minimize the buffer usage size and complexity of the HPLC operations for peroxidase purification. This process is readily scalable to a pilot plant and eventually to a production environment where mass production of material are expected to be produced.

• The Korean Journal of Nuclear Medicine
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• v.23 no.1
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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.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.621-623
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• 2015

This article describes a purification method yielding high purity of MFB produced from DMT production process. Aldehyde functional group of MFB included in side-products were converted to acetal compound via reacting with methanol and further separated. Hydrolysis process of the acetal product was continued under acidic condition and highly pure MFB were obtained with 90% yield. The structure of MFB was analyzed by $^1H$ NMR and $^{13}C$ NMR spectroscopy. Also, the purity of MFB was estimated to be over 99% by GC analysis.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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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.

• Journal of computational fluids engineering
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• v.16 no.4
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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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• v.40 no.2
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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.

• Archives of design research
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• v.15 no.2
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• pp.169-176
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• 2002

The purpose of this paper is to describe and predict the color trends of the handy electronic plastics product materials using design management based on a field survey in Korea and Japan. It is attempted to suggest more rational, systematic design process management of Korean firms, and to provide sharing of design knowledge management system among small businesses, home appliances, and the related organizations. Results of color trends survey shown plastics materials are cybertic, purity, and colorful trends. In addition, as emotional marketing strategy the trends of color and face processing are high quality, variety, and difference. Finally, this paper also suggests the way of DB building of color trends.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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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.

• Ceramist
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• v.22 no.4
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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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• v.30 no.10
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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).