• Journal of Applied Biological Chemistry
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• 제50권3호
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• pp.132-135
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• 2007

An efficient production method of chlorella extract was developed by enzymatic treatment using cell lytic and proteolytic enzymes. The suitable dosage of Tunicase, a cell lytic enzyme, was found to be 1.0% (w/w). Proteolytic enzymes were screened to obtain high chlorella growth factor (CGF) index, which indicates crude CGF content and solid recovery. Among the seven tested proteases, Esperase, whose optimal dosage was 1.0% (w/w), was selected. By co-treatment using optimal dosages of Tunicase and Esperase, the highest CGF index and solid recovery were obtained. The CGF index and solid recovery of co-treatment were remarkably enhanced by 250 ($4.36{\rightarrow}15.21$) and 220% ($12.65%{\rightarrow}40.15%$), respectively, than those of the non-treated extracts.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권1호
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• pp.21-25
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• 2002

To maximize and sustain the productivity of Monascus pigments, various environmental and nutritional parameters, such as the initial moisture content, pH, inoculum size, sample size, and nutrient supplement, that influence pigment production were evaluated in solid-state cultures as follows: initial moisture content, $50\%;$ pH, 6.0; inoculum size $1\;\times\;10^4$ spore cells $(grams\;of\;dry\;solid\;substrate)^{-1};$ sample size, 300 g. All supplementary nutrients (carbon, nitrogen, and mineral sources) added has inhibitory effects on the cell growth and red pigment production. In open tray culture the maximum biomass yield and specific productivity of red pigments were 223 mg DCW $(grams\;of\;initial\;dry\;substrate)^{-1}$ and, $47.6\;OD_{500}\;(DCW\;grams)^{-1}h^h{-1}$ respectively.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1421-1430
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• 2009

With an aim to evaluate dye decolorization by white rot fungus on natural living conditions, reproducing by solid-state fermentation, the process of triphenylmethane dyes decolorization using the white rot fungus P. ostreatus BP, cultivated on rice straw solid-state medium, has been demonstrated. Three typical dyes, including malachite green, bromophenol blue, and crystal violet, were almost completely decolorized by the fungus after 9 days of incubation. During the process of dye decolorization, the activities of enzyme secreted by the fungus, and the contents of soluble components, such as phenolic compounds, protein, and sugar, changed regularly. The fungus could produce ligninolytic, cellulolytic, and hemicellulolytic enzymes and laccase was the most dominant enzyme in solid-state medium. Laccase, laccase isoenzyme, and the laccase mediator could explain the decolorization of malachite green, bromophenol blue, and crystal violet by the fungus in solid-state medium, respectively. It is worth noting that the presence of the water-soluble phenolic compounds could stimulate the growth of fungus, enhance the production of laccase, and accelerate dye decolorization.

• 한국응용과학기술학회지
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• 제27권4호
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• pp.437-444
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• 2010

Dry Process(natural drying, hot-air drying, oil fry drying), optimized mixture ratio and the condition of carbonization was carried out in order to improve the product durability develop eco-friendly solid fuel mixing food waste and paper sludge. As a result of the experiment, oil fry drying process was the fastest method for drying food waste and paper sludge mixture that contains 80% water inside, and the optimized mixture ratio to minimize the generating concentration of chlorine gas against caloric value of mixture ratio was 7:3. Additionally proper temperature of product carbonization was about $200^{\circ}C$ and shown increasing product durability through the carbonization. Therefore, the pelletized solid fuel be shaped diameter around 0.5cm, length 2cm under which was pulverized and molded using 7:3 mixture of food waste, and paper sludge was the eco-friendly solid fuel possible to be industrialized which is consist of chlorine concentration of below 2.0wt% and the lowest caloric value of over 5,000kcal/kg. In conclusion, this developing manufacturing process of the solid fuel can be interpreted to contribute alternative energy development in accordance with low carbon and green growth era.

• Journal of Pharmaceutical Investigation
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• 제34권5호
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• pp.393-399
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• 2004

For the efficient determination of activity against solid tumors, an in vitro tumor model that resembles the condition of in vivo solid tumors, is required. The purpose of this study was to establish a rapid culture method and viability assay for an in vitro 3-dimensional tumor model, multicellular spheroid (MCS). Among 12 human cancer cell lines, a few cell lines including DLD-1 (human colorectal carcinoma cells) formed fully compact MCS which was adequate for in vitro viability assay. DLD-1 MCS showed steady growth reaching $700\;{\mu}m$ diameter after 11 day culture. DLD-1 cells grown as MCS showed significant increase in $G_0/G_1$ phase compared to the monolayer cells (73.9% vs 45.7%), but necrotic regions or apoptotic cells were not observed. The cells cultured as MCS showed resistance to 5-FU (10.3 fold higher $IC_{50}$) compared to monolayers, however, tirapazamine (a hypotoxin) showed similar activity in both culture systems. In summary, MCS may be a valid in vitro model for activity screening of anticancer agents against human solid tumors and also exploitable for studying molecular markers of drug resistance in human solid tumors.

• International Journal of Aerospace System Engineering
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• 제2권2호
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• pp.58-61
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• 2015

Combustion instability in solid rocket motors is a long-term open problem since the first rockets were used. Based on the numerous previous studies, it is known that the limit cycle amplitude is one of the key characteristics of the nonlinear combustion instability in solid rocket motors. Flandro's extended energy balance corollary, aims to predict the limit cycle amplitude of complex, nonlinear pressure oscillations for rockets or air-breathing engines, and leads to a precise assessment of nonlinear combustion instability in solid rocket motors. However, based on the comparison with experimental data, it is revealed that the Flandro's method cannot accurately describe such a complex oscillatory pressure. Thus in this work we make modifications of the nonlinear term in the nonlinear wave equations which represents the interaction of different modes. Through this modified method, a numerical simulation of the cylindrical solid rocket has been carried out, and the simulated result consists well with the experimental data. It means that the added coefficient makes the nonlinear wave growth equations describe the experimental data better.

• 생물환경조절학회지
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• 제13권3호
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• pp.135-142
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• 2004

본 연구는 당근과 양파에서 발아력 증진에 미치는 osmotic priming과 SMP효과를 비교하기 위해 수행되었다. Osmotic priming과 SMP 처리과정중 작물별 수분흡수율은 처리 1시간 후 급속한 수분흡수가 이루어졌고, 두 작물 모두 osmotic priming이 SMP보다 수분흡수 속도가 빨랐다. 이러한 경향은 처리 4시간까지 유지되었다. 처리최종일의 수분흡수율은 당근과 양파에서 osmotic priming이 SMP보다 2%높았다. Osmotic priming과 SMP 처리는 두 작물 모두 발아율을 향상시키지 못했지만 $T_{50}$ 및 MDG는 단축되어 조기발아 하였으며, 이러한 경향은 저온인 $15^{\circ}C$에서 더욱 현저하였다. Osmotic priming과 SMP 처리 후 초기함수율로 재건조하면 당근에서는 발아속도에 큰 차이가 없었으나, 양파에서는 표면건조에 비해 발아속도가 지연되었다. Osmotic priming과 SMP 상호처리간 발아력을 비교한 결과 두 작물 모두 SMP 처리가 osmotic priming보다 발아촉진에 효과적이었다. 당근과 양파종자를 osmotic priming과 SMP 처리하면 묘출현율도 향상되었고, 묘출현에 소요되는 일수를 단축시켜 신속한 묘출현을 유도하였다. 그러나 묘출현에 이은 유묘의 초기생육에는 통계적인 유의성은 인정되지는 않았으나 osmotic priming과 SMP 처리된 종자는 무처리에 비해 향상되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.131-131
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• 2013

A single-layer graphene has been uniformly grown on a Cu surface at elevated temperatures by thermally processing a poly(methyl methacrylate) (PMMA) film in a rapid thermal annealing (RTA) system under vacuum. The detailed chemistry of the transition from solid-state carbon to graphene on the catalytic Cu surface was investigated by performing in-situ residual gas analysis while PMMA/Cu-foil samples being heated, in conjunction with interrupted growth studies to reconstruct ex-situ the heating process. The data clearly show that the formation of graphene occurs with hydrocarbon molecules vaporized from PMMA, such as methane and/or methyl radicals, as precursors rather than by the direct graphitization of solid-state carbon. We also found that the temperature for vaporizing hydrocarbon molecules from PMMA and the length of time the gaseous hydrocarbon atmosphere is maintained, which are dependent on both the heating temperature profile and the amount of a solid carbon feedstock are the dominant factors to determine the crystalline quality of the resulting graphene film. Under optimal growth conditions, the PMMA-derived graphene was found to have a carrier (hole) mobility as high as ~2,700 cm2V-1s-1 at room temperature, superior to common graphene converted from solid carbon.

• 한국표면공학회지
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• 제43권1호
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• pp.7-11
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• 2010

Solid phase crystallization (SPC) is a simple method in producing a polycrystalline phase by annealing amorphous silicon (a-Si) in a furnace environment. Main motivation of the crystallization technique is to fabricate low temperature polycrystalline silicon thin film transistors (LTPS-TFTs) on a thermally susceptible glass substrate. Studies on SPC have been naturally focused to the low temperature regime. Recently, fabrication of polycrystalline silicon (poly-Si) TFT circuits from a high temperature polycrystalline silicon process on steel foil substrates was reported. Solid phase crystallization of a-Si films proceeds by nucleation and growth. After nucleation polycrystalline phase is propagated via twin mediated growth mechanism. Elliptically shaped grains, therefore, contain intra-granular defects such as micro-twins. Both the intra-granular and the inter-granular defects reflect the crystallinity of SPC poly-Si. Crystallinity and SPC kinetics of high temperatures were compared to those of low temperatures using Raman analysis newly proposed in this study.

• Journal of Welding and Joining
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• 제20권5호
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• pp.93-98
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• 2002

The effect of bonding misfit on single crystallization of transient liquid phase (TLP) bonded joints of single crystal superalloy CMSX-2 was investigated using MBF-80 insert metal. The bonding misfit was defined by (100) twist angle (rotating angle) at bonded interface. TLP bonding of specimens was carried out at 1523K for 1.8ks in vacuum. The post-bond heat treatment consisted of the solution and sequential two step aging treatment was conducted in the Ar atmosphere. The crystallographic orientation analysis across the TLP bonded joints was conducted three dimensionally using the electron back scattering pattern (EBSP) method. EBSP analyses f3r the bonded and post bonded heat treated specimens were conducted. All bonded joints had misorientation centering around the bonded interface for as-bonded and post-bond heat treated specimens with rotating angle. The average misorientation angle between both solid phases in bonded interlayer was almost identical to the rotating angle at bonded interface. HRTEM observation revealed that the atom arrangement of both solid phases in bonded interlayer was quite different across the bonded interface. It followed that grain boundary was formed in bonded interface. It was confirmed that epitaxial growth of the solid phase occurred from the base metal substrates during TLP bonding and single crystallization could not be achieved in joints with rotating angle.