Search | Korea Science

제훈성;최차용
- KSBB Journal
- /
- v.7 no.2
- /
- pp.92-95
- /
- 1992
A model for the role of serum was proposed to develop a low serum medium for the large scale cu1ture of mammalian cell. The strategy of medium development adopted in this study facilitated the understanding of the role being carried out by the serum in the culture of hybridoma KAl12 cell line. In this model, the serum components were divided into two main groups : the first group encompasses the nutrient factors that determine the maximum cell density and the second group includes the growth factors that regulate the cell growth rate, The model prediction was compared with the experimental results. The model enabled us to find out several useful aspects of medium composition for cell growth. 1) One particular component in the basal medium became limiting factor when serum concentration level was more than 7%. 2) The growth regulating factors and nutrient factors limited the cell growth at 3% and 5% serum concentration levels respectively.
PDF

Lee, Dong-Hun;Kim, Chang-Joon;Kim, Sung-Bae
- Microbiology and Biotechnology Letters
- /
- v.37 no.3
- /
- pp.226-230
- /
- 2009
Rice straw was pretreated using dilute sulfuric acid at reaction conditions covering two levels of reaction temperature (140, $150^{\circ}C$) and five levels of acid concentrations ($1.0{\sim}3.0%wt$). The production and decomposition rates of major components of rice straw indicating glucose, xylose, galactose and arabinose were investigated. The production rate of arabinose and the decomposition rate of xylose were greatest among them. The maximum attainable hemicellulose (xylose+galactose+arabinose) yield was about 80%. High acid concentration appears to favor the maximum yield but high temperature does not. The optimum condition was found to be $140^{\circ}C$, 2.5% and 20 minutes. The maximum glucose yields were almost same, around $16{\sim}18%$, regardless of reaction conditions.
PDF KSCI

Lee, Won-Beom;Park, Seong-Ho
- Proceedings of the Korean Society for Technology of Plasticity Conference
- /
- 2004.05a
- /
- pp.365-372
- /
- 2004
The laser welding and its analysis were carried out using high power 6kW $CO_2$ laser for high strength steels such as DP, TRIP and conventional high strength steels. Bead on plate welding of thin sheet was examined to investigate the effect of weld variables of laser welding, and to obtain optimum welding condition. In order to investigate the formability of welded high strength steels, LDH test was added on this work. At high welding speed, the partial penetration was obtained by low heat input. Meanwhile, porosity was formed in the bead at low weld speed because of extremely higher heat input. The optimum welding condition of welding was derived from bead width, penetration and hardness property. It was shown that the DP steels had lower porosity level and smooth bead shape, therefore better laser weldability than TRIP steels and conventional high strength steels. In addition, LDH test shows that the welded DP steels have about $90\%$ formability value of base metal, although TRIP steel and conventional high strength steels have about $80\%$ formability value of its base metal.
PDF