• Journal of Microbiology and Biotechnology
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• v.29 no.10
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• pp.1656-1664
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• 2019

Isoprene has the potential to replace some petroleum-based chemicals and can be produced through biological systems using renewable carbon sources. Ralstonia eutropha can produce value-added compounds, including intracellular polyhydroxyalkanoate (PHA) through fatty acid and lipid metabolism. In the present study, we engineered strains of R. eutropha H16 and examined the strains for isoprene production. We optimized codons of all the genes involved in isoprene synthesis by the mevalonate pathway and manipulated the promoter regions using pLac and pJ5 elements. Our results showed that isoprene productivity was higher using the J5 promoter ($1.9{\pm}0.24{\mu}g/l$) than when using the lac promoter ($1.5{\pm}0.2{\mu}g/l$). Additionally, the use of three J5 promoters was more efficient ($3.8{\pm}0.18{\mu}g/l$) for isoprene production than a one-promoter system, and could be scaled up to a 5-L batch-cultivation from a T-flask culture. Although the isoprene yield obtained in our study was insufficient to meet industrial demands, our study, for the first time, shows that R. eutropha can be modified for efficient isoprene production and lays the foundation for further optimization of the fermentation process.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.3 s.116
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• pp.72-78
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• 2006

The extraction properties of the biological waste originated from the Tobacco industry were evaluated. The biological waste have been recycled and transformed into a valuable material, so called a reconstituted tobacco sheet(Recon) by the papermaking process. In this process, The mechanical extraction process, which divides the mixed raw material slurry into the soluble stock and the insoluble stock, could affect not only the quality of final Recon product but also the productivity of whole Recon making process. This study investigated the effects of the extraction process on the slurry properties in detail. In order to quantify the amounts of the solubles which resided in the insoluble fibers, the washing treatment of the stock before and after squeezing process was applied. The amounts of the residual solubles showed little changes according to each stage of the extraction process. The fractionation of the slurry showed the difference in the amount of soluble in the stock depending on the size of the biological waste. After the extraction process, the bigger size fiber portion contained about 19%(by weight) in soluble after pressing but the smaller size fiber portion 9% in soluble. The fractionation ratio of the stocks also was changed by the screw press process, which could demonstrate the physical effects of the mechanical extraction.

• Environmental Engineering Research
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• v.25 no.4
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• pp.597-604
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• 2020

In the present study, the application of sequential biological and photocatalytic process was evaluated as a feasible process for the degradation of imidacloprid (IMI) in soil. Photocatalysis was carried out as a post and pre-treatment to the biological process as Microbial Photocatalytic (MP) and Photocatalytic Microbial (PM), respectively, to enhance the degradation and mineralization of IMI in soil. By both the processes, there was an enhancement in the percentage degradation of IMI i.e 86.2% for PM and 94.6% for MP process. The obtained results indicate that MP process is apparently more efficient in degradation of IMI which was observed with 15 days of biological treatment followed by 18 h of photocatalytic degradation (15 d + 18 h). The present work also reveals that though the difference in terms of the degradation of IMI after 5 d + 18 h, 10 d + 18 h & 15 d+ 18 h of MP process is not drastic, yet significant variation has been observed in terms of mineralization that truly signifies the removal of IMI from the soil. The LC analysis has shown that the intermediates formed during MP process are more and smaller in comparison to PM process, which further provides evidence that MP process is better than PM process for effective degradation of IMI in soil.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.16-23
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• 2012

Recently, as organizational systems have become larger and more complicated, the evaluation for their efficiency and effectiveness has become more difficult but important. It is essential to understand the current strength and weakness of the organizational process. It can be a starting point for improving the efficiency and effectiveness of the organizational systems, because the quality of system outputs depend greatly on the capability of system process. Particularly in such process-based industries as semiconductor, energy or software industries, an assessment of process capability is more highlighted to gain knowledge of the expected quality and reliability of system outputs. As a result, much attention has been given to the issues of process capability assessment in the process-based industries. However, most of the previous research in those industries is based on case studies, a more generalized method for process capability assessment is in need for help more companies improve their processes. Therefore, this study aims to propose a process capability assessment method and apply the proposed method to an energy company. This research argues that the process capability is composed of individual and organizational capabilities of the process. Then, the concept of Capability Maturity Model Integration, which was initially suggested to evaluate the software development process, was introduced to develop the assessment tools and process. Finally, the proposed method was applied to a Korean company in the energy industry sector to verify its utility. The research outputs are expected to help more firms assess their process capability and ultimately improve the process.

• Carbon letters
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• v.14 no.3
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• pp.152-161
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• 2013

Needle coke is an important material for graphite electrodes. Delayed coking is used to produce needle coke. Producing good quality needle coke is not simple because it is a multi-parameter controlled process. Apart from that, it is important to understand the mechanism responsible for the delayed coking process, which involves mesophase formation and uniaxial rearrangement. Temperature and pressure need to be optimized for the different substances in every feedstock. Saturate hydrocarbon, aromatic, resin and asphaltene compounds are the main components in the delayed coking process for a low Coefficient Thermal Expansion value. In addition, heteroatoms, such as sulphur, oxygen, nitrogen and metal impurities, must be considered for a better graphitization process that prevents the puffing effect and produces better mesophase formation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.2
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• pp.61-66
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• 1998

Glycolipids produced by Pseudomonas aeruginosa YPJ-80 were characterized by chromatographic and spectorscopic techniques as a mixture of two rhamnolipids. For recovery of glycolipids from the culture broth, various isolation methods including ultrafiltration, adsorption and solvent extraction were compared. Ultrafiltration showed the best results in terms of glycolipids recovery. Further purification for spectroscopic analysis was carried out by adsorption chromatography and preparative thin layer chromatography. From the spectroscopic analysis, such as IR spectroscopy. FAB-MS, 1H-NMR and 13C-NMR and hydrolysis analysis, the glycolipids were identified as L-${\alpha}$-rhamnopyranosyl-${\beta}$-hydroxydecanoly-${\beta}$-hydroxydecanoate and 2-O-${\alpha}$-L-rhamnopyranosyl-${\alpha}$-L-rhamnopyranosyl-${\beta}$-hydroxydecanoyl-${\beta}$-hydroxydecanoate. Monorhamnolipid and dirhamnolipid lowered the surface tension of water to 28.1 mN/M and 29.3 mN/m, respectively.

• Journal of the Korean housing association
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• v.22 no.3
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• pp.47-57
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• 2011

The purpose of this research consists in the process analysis and studying of the Residents-Participated Workshop which aims to improve the environment of common areas at the rental apartments, and also to present the spacial designs for the improved environment. The objects of this research are Susojugong Rental Apartments and total 3 Residents-Participated Workshops were held. The contents of the research are as follows; 1) Background and purposes of resident environmental improvement and associated group of people were examined. 2) Execution of Residents-Participated Workshop programs and the analysis of the process to present the plans of environmental improvement. The results of the research are; 1) representing variety of opinions and the increased sense of participation. 2) possibility of presenting designs initiated by residents through participatory design workshop. 3) improvement of relationships between managerial authorities, specialists and residents. 4) the place of interchange among residents. 5) necessity of assisting workshop tool, Resident-Participated Workshop programs and schedules. Environmentally improved designs which were presented at the workshop have been actually demonstrated at the Rental Apartments of this research. Follow up research on the process of construction, maintenance management of the construction after completion and the full contents should be studied further.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.245-246
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• 2012

Lately the Infill Modular Construction System which meets the domestic standards about the structure and fireproof performance and which is applied to the remodeling techniques is being emphasized. In order to introduce the Infill Modular Construction System to domestic market successfully, the development of insufficient element technologies and systematic analysis of process should be preceded. This research aims to establish of Standard Construction Process, as advanced research for the settlement of the Infill Modular Construction System. As advanced research for the activation of the Infill Modular Construction System, this research aims to develop Infill Unit Module's mobile device. This is expected to improve work efficiency. In addition organizing optimized Standard Construction Process by steady work analysis and improvement is being planned.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.103-122
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• 2003

This research shows that as the use of IT spreads, the Investments of IT must be accompanied by the innovation of the business process of an organization to increase productivity. It examines closely to the relations between these by presenting a theoretical formula, with related-theories at the basis, that shows the characteristics of IT Infrastructure and heightens the results of organization. In previous researches, various results co-exist in presenting the direct relativeness between IT Infrastructure and results of organization. But in this research, a parameter called business process has been included making it possible to analyze even the indirect effects to the results of organization. Also, the difference and relativity between the IT Infrastructure and business process groups according to the company environment factor has been proved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.234-234
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• 2010

Most high efficiency silicon solar cells use a passivated selective emitter. It have been an important research subject for crystalline silicon solar cells for decades. It is being used in production for high efficiency solar cells. Most of the selective emitter process require expensive extra masking, etching steps, and a double diffusion process making selective emitters not cost effective. In this paper, we study method for single diffusion step selective emitter process as an alternative to not cost effective double diffusion process. Cost effective selective emitter that the efficiency should be increased significantly (mare than 0.2%) and that the process should simple, robust and cheap.