• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.233-236
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• 2000

Bacillus thuringiensis (Bt) is the most widely used microbial insecticide in the biological control market. Cultivation of the microorganism to high cell densities offers potential for enhancing the rate of formation as well as the concentration of the desired products In the fermentation broths in bioreactor. With this objective, we developed the new bioreactor incorporating ceramic membrane module for the retention of cell mass. Cell yield and spore formation of Bacillus thuringiensis was improved markedly by adopting this new bioreactor based on glucose -limited feeding operation. It was possible to grow the cell and the heat-resistant spore to above $1.2\;{\times}\;10^{10}\;CFU/ml$ density. With glucose-limited operation, we studied the growth behavior of Bacillus thuringiensis during the cell retention culture. Linear growth of Bacillus thuringiensis was observed under glucose-limited culture, which matched well with simple mathematical model of cell retention culture.

• Journal of Conservation Science
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• v.36 no.6
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• pp.578-590
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• 2020

During the 1960-1970s, a group of ceramic conservation scientists and ceramic historians in South Korea came together and established their own disciplines. While the two disciplines share the same ceramics as the subjects of their research, there has been little interaction between the two as their research outputs are articulated in remarkably different languages. This paper aims to address the following questions by using a case study that focuses on the research on white porcelains centered on the project of Gyeonggi Museum and a series of studies conducted by one of the museum's project research teams. First, what are the characteristics of and differences between the explanation styles of the two disciplines that share the same research subjects of ceramics? Second, why has the communication between the two disciplines become difficult? Third, if there can be a trading zone wherein the two disciplines would be able to communicate again, what would be its epistemic conditions? The focus of this paper is the relationship between scientific data and ordinary language, which the two disciplines have shared from their inception. By analyzing the relationship, I first argue that, as the analytical techniques of conservation science have become more developed, conservation science's data have gradually lost its relevance in ceramic history, in spite of a shared common language between them; Second, I argue that by recovering the import of shared language again, the scientific data can be placed in a different practical context, providing novel interpretations that are relevant and often consequential to ceramic history.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1165-1173
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• 2014

For the field application of dielectric barrier discharge plasma reactor in nutrient solution culture, a filtration-DBD (dielectric barrier discharge) plasma reactor was investigated for the Ralstonia solanacearum which causes bacterial wilt in aquiculture. The filtration-DBD plasma reactor system of this study was consisted of filter, plasma reactor, reservoir. The DBD plasma reactor consisted of a quartz dielectric tube, discharge electrode (inner) and ground electrode (outer). The experimental results showed that the inactivation of R. solanacearum with filter media type in filter reactor ranked in the following order: anthracite > fiber ball > sand > ceramic ball > quartz ceramic. In filtration + plasma process, disinfection effect with the voltage was found to small. In disinfection time of 120 minutes, residual R. solanacearum concentration was 1.17 log (15 CFU/mL). When the continuous disinfection time was 120 minute, disinfection effect was thought to keep the four days. In sporadic operation mode of 30 minutes disinfection - 24 hours break, residual R. solanacearum concentration after five days was 0.3 log (2 CFU/mL). It is considered that most of R. solanacearum has been inactivated substantially.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.3
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• pp.227-237
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• 2008

STATEMENT OF PROBLEM: Zirconium oxide can be a substitute to titanium as implant materials to solve the esthetic problems of dark color in the gingival portion of implant restorations. PURPOSE: This study was performed to define attachment and growth behavior of osteoblast- like cells cultured on grooved surfaces of zirconium oxide and evaluate the genetic effect of zirconium oxide surfaces using the reverse transcriptase-polymerase chain reaction (RT-PCR). MATERIAL AND METHODS: MC3T3-E1 cells were cultured on (1) commercially pure titanium discs with smooth surface (T group), (2) yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) with machined surface (ZS group), and (3) Y-TZP with $100{\mu}m$ grooves (ZG group). Cell proliferation activity was evaluated through MTT assay and cell morphology was examined by SEM. The mRNA expression of Runx2, alkaline phosphatase, osteocalcin, TGF-${\beta}1$, IGF-1, G3PDH in E1 cells were evaluated by RT-PCR. RESULTS: From the MTT assay, after 48 hours of adhesion of MC3T3-E1 cells, the mean optical density value of T group and ZG group significantly increased compared to the ZS group. SEM images of osteoblast-like cells showed that significantly more cells were observed to attach to the grooves and appeared to follow the direction of the grooves. After 24 hours of cell adhesion, more spreading and flattening of cells with active filopodia formation occurred. Results of RT-PCR suggest that T group, ZS group, and ZG group showed comparable osteoblast-specific gene expression after 24 hours of cell incubation. CONCLUSION: Surface topography and material of implants can play an important role in expression of osteoblast phenotype markers. Zirconia ceramic showed comparable biological responses of osteoblast-like cells with titanium during a short-time cell culture period. Also, grooves influence cell spreading and guide the cells to be aligned within surface grooves.

• Journal of Periodontal and Implant Science
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• v.46 no.6
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• pp.362-371
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• 2016

Purpose: The increasing demand for esthetically pleasing results has contributed to the use of ceramics for dental implant abutments. The aim of this study was to compare the biological response of epithelial tissue cultivated on lithium disilicate ($LS_2$) and zirconium oxide ($ZrO_2$) ceramics. Understanding the relevant physicochemical and mechanical properties of these ceramics will help identify the optimal material for facilitating gingival wound closure. Methods: Both biomaterials were prepared with 2 different surface treatments: raw and polished. Their physicochemical characteristics were analyzed by contact angle measurements, scanning white-light interferometry, and scanning electron microscopy. An organotypic culture was then performed using a chicken epithelium model to simulate peri-implant soft tissue. We measured the contact angle, hydrophobicity, and roughness of the materials as well as the tissue behavior at their surfaces (cell migration and cell adhesion). Results: The best cell migration was observed on $ZrO_2$ ceramic. Cell adhesion was also drastically lower on the polished $ZrO_2$ ceramic than on both the raw and polished $LS_2$. Evaluating various surface topographies of $LS_2$ showed that increasing surface roughness improved cell adhesion, leading to an increase of up to 13%. Conclusions: Our results demonstrate that a biomaterial, here $LS_2$, can be modified using simple surface changes in order to finely modulate soft tissue adhesion. Strong adhesion at the abutment associated with weak migration assists in gingival wound healing. On the same material, polishing can reduce cell adhesion without drastically modifying cell migration. A comparison of $LS_2$ and $ZrO_2$ ceramic showed that $LS_2$ was more conducive to creating varying tissue reactions. Our results can help dental surgeons to choose, especially for esthetic implant abutments, the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.112-123
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• 2006

Purpose: The biocompatibility and bio-adhesive property of a dental implant abutment are important for proper soft tissue healing and maintenance of osseointegration of implant. However, studies of soft tissue healing and mucosal attachment of various materials of implant abutment other than titanium are still needed. In this study, cell attachment, proliferation, cytotoxicity of human gingival fibroblast for ceramic, gold alloy, Ni-Cr alloy and, commercially available pure titanium as a control were evaluated, using MTS and scanning electron microscopy. Materials and Methods: Specimen was designed to disc, 4mm diameter and 1mm thickness, made of ceramic, gold alloy, Ni-Cr alloy and commercially available pure titanium. Primary culture of human gingival fibroblasts were grown in Dulbecco's modified Eagle's medium with 10% fetal bovine serum and 1% antibiotics. Cells were inoculated in the multiwell plates placed the specimen disc. Cell Titer 96 AQucous One Solution Cell Proliferation Assay were done after 1hour 3hours, 24hours, 3days, 5days of incubation. The discs were processed for scanning electron micrography to evaluate cell attachment and morphologic change. Results: The results were obtained as fellows. 1. The ceramic showed high cell attachment and proliferation and low cytotoxicity, which is as much bioadhesive and biocompatible as titanium. 2. The gold alloy represented limited proliferation of human gingival fibroblast and the highest cytotoxicity among tested materials (p<0.05). 3. The Ni-Cr alloy limited the proliferaion of the human gingival fibroblast compared to titanium(p<0.05) but cytotoxicity on the bottom of well was not so considerable, compared to titanium. 4. On the scanning electron micrographs , the ceramic showed good attachment and proliferation of human gingival fibroblast, which was similar to titanium. But gold alloy and Ni-Cr alloy showed the shrinkage of gingival fibroblast both after 24 hours and 3 days. On 5th day, small amount of the human gingival fibroblast proliferation was observed on the Ni-Cr alloy, while the shrinkage of gingival fibroblast was still observed on the gold alloy. Conclusions: These results suggest that the ceramic abutment is as biocompatible as titanium to make proper mucosal seal. The gold alloy has a high cytotoxicity to limit proliferation of gingival fibroblast, which suggest limited use on the anterior tooth where soft tissue healing is recommeded.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.527-532
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• 2015

There are crafts industry has a complex nature of the artistic and cultural features. Artistic features are deemed to be areas of strong artistic personalities of the artistic and intellectually formative activities that embody creative ideas. Crafts and cultural features of the culture industry "creates" are as that meet the essential needs of human being sand has been used on part of cultural goods industry. Cultural industry crafts cultural products in terms of culture and traditional craft industry is tinge creativity to express ethnic uniqueness production is intended to study the part of the surge in demand by examining income levels and cultural life of modern man. In this study, we investigate the status of the craft industry for cultural goods. Based on this study of what is likely a problem with the craft industry and research, we propose away to melt complex ways.

• The Research Journal of the Costume Culture
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• v.15 no.5
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• pp.749-759
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• 2007

As the traditional style is treated as one of the important themes in fashion recently, how to apply the formative character in Korean and Japanese traditional dress to modern fashion is searched through actual analysis of photograph material, Both design formative elements were confirmed by clothing and fashion department majors through visual data so that 20 pieces of them were selected as final analysis object. Korean traditional dress form in modern fashion emphasizes curvaceousness as plane division. On the other hand, that of Japanese shows straight line, layered, belt, big look through up & down connection style. Color in Korean traditional dress prefers white and original color and modern fashion displays the natural beauty through harmony of similar colors ; that of Japanese based on natural color such as persimmon color cherishes natural beauty and implicit moderation showing harmony of various original color with brilliance and neutral color. While texture in Korean traditional dress was fine and exquisite, that of Japanese preferred coarse and tactile ones. In motif, Korea was natural and geometric but Japanese variously used complex and geometric ones. Likewise, the result suggests that the formative character in Korean and Japanese modern fashion affects the modern dress format as new aesthetic sense and takes on more complicated and subtle aspect in basic form, not just use so far.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.419-427
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• 1991

Ethanol fermentation of glucose by a strain of Saccharomyces cereuisiae was studied in membrane recycle bioreactor, where the fermentation vessel was coupled with cross flow hollow fiber membrane. The cell recycle system controlled backflushing with fresh medium was proven to be effective in alleviating membrane fouling and allowing long term operation of high-cell continuous fermentation. Using 100 g/l initial glucose concentration, the maximum productivity of about 9 5 g/$l \cdot h$ has been achieved at dilution rate 2.5 $h^{-1}$ and bleed stream ratio 0.05 with the corresponding ethanol concentration of 35g/l and glucose conversion of 100%. Increasing the glucose concentration to 200 g/$l \cdot h$ resulted in an increase in ethanol concentration to 48 g/l and productivity to 120 g1l.h. Substrate conversion, however, was only 69%. This productivity was the highest value in the study, and about 38 fold more than that of batch culture and 17 fold more that of single stage continuous culture without cell recycling. No further increase in the productivity was obtained when the glucose concentration was increased reased to 300g/l.

• Journal of the Korean Society of Food Culture
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• v.19 no.2
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• pp.139-149
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• 2004

The age of Queen Victoria, so called nearly 64 years from 1837 to 1901 that Queen Victoria was on the throne. It was the time that ceramicwares and silverwares were mass-produced thanks to the Industrial Revolution and then diverse directions of dining space could be possible in middle class. At the same time, it was the time that the production of bone china, which is main current in modem times, became established, ironstone china began to be developed, and white ceramic wares were accomplished. In addition, factors for the direction of dining space were mass-produced and Gothic style, Classic style, Majolica style, Renaissance, and Neo-rococo style had come back into fashion. Therefore, diverse designs coexisted and had great effect on dining space in this times. This study purposed to establish the decoration theory of dining space following historic flow through researching the designs and the direct factors for dining space in the age of Queen Victoria.