• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.36-40
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• 1999

Optimal lyophilization process was developed for manufacturing the dried product of Lactobacillus acidophilus with high cell viability. Three major factors, freezing rate, specific surface area of samples, and stabilizer type and their synergy were shown to play a crucial role in the development of an effective lyophilization process. Finally we found an optimal combination among three process parameters mentioned above; an exceptionally high cell survival percentage of 90% was achieved using the 8.28 cm-1 specific surface area of samples, slow freezing rate, and a stabilizer composition of 4% skim milk +1% glycerol +0.1% calcium chloride.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.11a
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• pp.191-194
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• 2002

매체 순환식 연소(Chemical-Looping Combustion, CLC)는 금속 산화물(산소공여매체, oxygen carrier)의 산소를 이용하여 화석연료를 산화(연료 연소 공정)시키고, 환원된 금속을 다시 산화(매체 산화 공정)시키는 간접적인 연소 공정의 하나이다. 이 방식은 온실효과의 주발생원인 $CO_2$를 원천적으로 회수할 수 있고, 또한 화염이 없는 상태에서 연소반응이 진행됨으로 thermal NOx의 발생을 미연에 방지할 수 있어 고효율의 환경친화적인 연소공정이다.(중략)

• Membrane and Water Treatment
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• v.11 no.4
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• pp.303-312
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• 2020

This study aims to investigate at a laboratory scale fluorides removal from an industrial wastewater having excessive F^- concentration through a hybrid process combining neutralization and membrane separation. For the membrane separation operation, both Reverse Osmosis (RO) and Nanofiltration (NF) were investigated and confronted. The optimized neutralization step with hydrated lime allowed reaching fluoride removal rates of 99.1± 0.4 %. To simulate continuous process, consecutive batch treatments with full recirculation of membrane process brines were conducted. Despite the relatively high super saturations with respect to CaF₂, no membrane cloaking was observed. The RO polishing treatment allowed decreasing the permeate fluoride concentration to 0.9± 0.3 mg/L with a fluoride rejection rate of 93± 2% at the optimal transmembrane pressure of around 100 psi. When NF membrane was used to treat neutralization filtrate, the permeate fluoride concentration dropped to 1.1± 0.4 mg/L with a fluoride rejection rate of 88± 5% at the optimal pressure of around 80 psi. Thus, with respect to RO, NF allowed roughly 20% decrease of the driving pressure at the expense of only 5% drop of rejection rate. Both NF and RO permeates at optimal operating transmembrane pressures respect environmental regulations for reject streams discharge into the environment.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.785-795
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• 2019

This paper is a study on the modeling of the quantity estimation model for offshore plant Material handling equipment in FEED(Front End Engineering Design) verification stage using system engineering approach which is an engineering design methods. The relevant engineering execution procedure is not systemized although the operation method and Material handling equipment selection with weight and space constraints is a key part of the FEED. Using the system engineering process, the stakeholder requirements analysis process, the system requirements analysis, and the final system architecture design were sequentially performed, and the process developed through the functional development diagram and Requirement traceability matrix (RTM) was verified. In addition, based on the established process, we propose a Material handling quantity estimation model and Quantity calculation verification Table that can be applied at the FEED verification stage and we verify the applicability through case studies.

• Journal of the Korean Ceramic Society
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• v.52 no.2
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• pp.133-136
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• 2015

The outward diffusion of $Na^+$ ions in iron-bearing soda lime silicate glass via oxidation heat treatment before the ion exchange process is artificially induced in order to increase the amount of ions exchanged during the ion exchange process. The effect of the addition process is analyzed through measuring the bending strength, the weight change, and the inter-diffusion coefficient after the ion exchange process. The glass strength is increased when the outward diffusion of $Na^+$ ions via oxidation heat treatment before the ion exchange process is added. For the glass subjected to the additional process, the weight change and diffusion depth increase compared with the glass not subjected to the process. The interdiffusion coefficient is also slightly increased as a result of the additional process.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.586-587
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• 2005

• Proceedings of the Membrane Society of Korea Conference
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• 2005.11a
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• pp.148-151
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• 2005

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.1
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• pp.48-49
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• 1998

A protocol for the transformation of Klebsiella oxytoca by electroporation was developed. Preparation of competent cells at early exponential phase was most critical to obtain high transformation efficiency. The highest efficiency of 1.6$\times$106 transformants per $\mu\textrm{g}$ DNA(pBR322) could be obtained by electroporation of K. oxytoca cells prepared at the OD600 of 0.2 with 1.25$\mu\textrm{g}$ DNA at the filed strength of 2.5kV, the parallel resistance of 200$\Omega$ and capacitance of 25$\mu$F.

• Industrial Engineering and Management Systems
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• v.11 no.4
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• pp.346-352
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• 2012

While systems engineering has been widely applied to complex system development, some evidences are reported about major budget and schedule overruns in systems engineering applied. On the other hand, many organizations have been deploying Design for Six Sigma (DFSS) to build Six Sigma momentums in the area of design and development for their products and processes. To explore the possibility of having a DFSS complement systems engineering process, this process reviews the systems engineering with their categories of effort and DFSS with its methodologies. A comparison of the systems engineering process and DFSS indicates that DFSS can be a complement to systems engineering for delivering higher quality products to customers faster at a lower cost. We suggest a simplified framework of systems engineering process, that is, PADOV which was derived from the generic systems engineering process which has been applied to the development of T-50 advanced supersonic trainer aircraft by Korea Aerospace Industries (KAI) with technical assistance of Lockheed Martin. We demonstrated that each phase of PADOV framework is comprehensively matched to the pertinent categories of systems engineering effort from various standards.

• 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.