• 한국전산유체공학회:학술대회논문집
• /
• 2005.10a
• /
• pp.55-59
• /
• 2005

CFD analysis has been conducted to find the two stage impeller configuration which is the most suitable for a stirred tank with an internal helical cooling coil and a cooling jacket, which is frequently used in chemical industries for highly exothermic reactions ranged from low to medium viscosity. Two typical types of impellers are considered; pitched paddle impellers and Rushton turbine impellers. Interestingly, pitched paddle impellers show a good mixing performance for multi-species, whereas Rushton turbine impellers achieve a good mixing performance for multi-phases. Besides the type of an impeller, the location of an impeller is another important factor to be considered in order to accomplish an effective mixing. The best set of types and locations of two impellers is recommended based on the coefficient of variation(CoV) value and the heat removal capability obtained from CFD results. The former is a measure to quantify the degree of mixing.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2002.11a
• /
• pp.111-116
• /
• 2002

고온의 소듐을 냉각재로 사용하는 풀형 액체금속로인KALIMER[1]는 기존의 경수로에 비해 고온에서 운전되므로, 잔열제거계통은 공기 자연순환에 의해 격납용기(CV) 외벽을 직접 냉각하는 방식의 PSDRS(Passive Safety-grade Decay Heat Removal System)[1]를 사용하며, 특히 고온의 구조물 표면온도에 의해 대류전열 외에도 복사전열과정이 활발히 일어난다.(중략)

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.22 no.3
• /
• pp.11-19
• /
• 2009

석곡은 난초과의 여러해살이풀 Dendrobium moniliforme의 지상부를 건조한 것으로 예로부터 양위생진(養胃生津), 자음제열(滋陰除熱) 등의 효능이 있어 해열, 진통의 작용과 위액분비 촉진, 혈압강하의 작용이 있는 것으로 알려져 있다. 본 연구에서는 석곡의 항염증 작용 기전을 알아보기 위하여 석곡 열수추출물을 대식세포주에 처리하여 NO 및 IL-$1{\beta}$의 생성에 미치는 영향을 조사하였다. LPS로 자극된 대식세포주 RAW264.7 세포에서 석곡은 NO 및 IL-$1{\beta}$ 생성과 iNOS 단백질 발현을 저해하였으며, LPS에 의해서 활성화되는 ERK, p38, JNK 효소의 활성을 현저히 억제하였다. 이 결과들로 보아 석곡의 항염증 작용이 MAPK 활성 저해로 인한 NO 및 IL-$1{\beta}$ 생성의 억제 때문인 것으로 사료된다.

• Nuclear Engineering and Technology
• /
• v.10 no.3
• /
• pp.127-136
• /
• 1978

We have applied the temperature dependent Thomas-Fermi theory to evaluate the equations of state, chemical potentials, entropies, % ionizations, total energies and kinetic energies of an atom, and seveal thermodynamic quantifies of one of metallic substance, Na, for a density range of 0.1$\rho$$_{0}$ ~ 10$\rho$$_{0}$, where $\rho$$_{0}$ is the normal density of Na at its melting point, and for a temperature range of 60.88Ryd. ~0.0216 Ryd., where the system is expected to be in a gaseous or liquid state. The main interest of present work lies in physical quantities at high temperatures and high densities, however, we have included those quantities of Na at sufficiently low temperatures and low densities to show that the approximation is not so crude as one might expect. Particularly, at high temperatures, the calculated equations of state, kinetic energies of an atom, chemical potentials and entropies are compared with those, of an ideal Fermi gas. The results show that, at high temperatures, the agreement seems good for chemical Potentials. However, the differences in, entropy, kinetic energy of an atom, and equation of state are not negligible even at such high temperature as $textsc{k}$T=60.88Ryd.