• 한국축산식품학회지
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• 제18권4호
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• pp.285-291
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• 1998

Adsorption isotherms of water vapour for infant formula milk powders manufactured by P. M. and N company in Korea were measured at temperatures between 20, 30 and 40$^{\circ}C$ using COST-90 modified method. Results showed that the isotherms were sigmoidal in shape. The adsorption isotherms of milk powder were depending on the temperature and products. The BET-model were applied and analyzed to compare the experimental value. It was found that the BET-model is fitted with measuring data. Sample P showed the lowest monolayer value and sample N showed the highest. Isosteric heat obtained upon application of BET-model was calculated in this field of temperature using the Clausius-Clapeyron equation. It is suggested that the usage of the BET-model to estimate the heat of water sorption in infant formula milk powder should be in agreement with the results from COST-90 project.

• Korean Chemical Engineering Research
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• 제49권4호
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• pp.456-459
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• 2011

본 연구는 흡착 능이 서로 다른 두 가지 활성탄을 혼합하여 최적의 흡착 능을 발휘코자 혼합할 때 그들의 최적혼합비를 구하는 방법을 제시하고자 하였다. 활성탄의 세공특성과 흡착 능은 BET-분석에 의해 얻어지는 흡착등온곡선으로 판별하며 이는 역시 흡착필터설계의 기본적 정보를 제공한다. 따라서 고도의 BET-model의 흡착 능을 보이는 석탄 계활성탄과 낮은 Langmuir-model을 보이는 야자각계 활성탄의 혼합하는 extreme case와, 고, 저 비표면적을 가진 두 가지 활성탄을 혼합하는 middle case 및 전, 후 case의 상호 교차 배합하는 cross case 등, 3가지 시험을 수행했으며, 이를 위해 시판 품 외에 국내 한 공인 연구소가 연구용시료로서 제공한 고비표면적의 두 가지 활성탄에도 적용하여 본 방법의 타당성을 확인하였다.

• Environmental Engineering Research
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• 제22권1호
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• pp.95-107
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• 2017

Adsorption equilibrium and kinetic behavior of two toxic heavy metals hexavalent chromium [Cr(VI)] and mercury [Hg(II)] on mustard oil cake (MOC) was studied. Isotherm of total chromium was of concave type (S1 type) suggesting cooperative adsorption. Total chromium adsorption followed BET isotherm model. Isotherm of Hg(II) was of L3 type with monolayer followed by multilayer formation due to blockage of pores of MOC at lower concentration of Hg(II). Combined BET-Langmuir and BET-Freundlich models were appropriate to predict Hg(II) adsorption data on MOC. Boyd's model confirmed that external mass transfer was rate limiting step for both total chromium and Hg(II) adsorptions with average diffusivity of $1.09{\times}10^{-16}$ and $0.97m^2/sec$, respectively. Desorption was more than 60% with Hg(II), but poor with chromium. The optimum pH for adsorptions of total chromium and Hg(II) were 2-3 and 5, respectively. At strong acidic pH, Cr(VI) was adsorbed by ion exchange mechanism and after adsorption reduced to Cr(III) and remained on MOC surface. Hg(II) removal was achieved by complexation of $HgCl_2$ with deprotonated amine ($-NH_2$) and carboxyl (COO-) groups of MOC.

• 분석과학
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• 제24권6호
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• pp.503-509
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• 2011

비표면적은 기능성 나노소재의 특성평가에 있어 매우 중요한 지표가 되고 있다. 하지만 비표면적 측정은 측정방법 및 해석 방법에 따라 결과에 많은 차이가 있어왔다. 국내에 보급된 비표면적 측정장치의 신뢰성 검증을 위하여, 21개 산학연 기관을 대상으로 순회평가(RRT)를 수행하였다. 순회평가 분석 결과 많은 기관에서는 비표면적 측정장비의 흡착량 측정 성능에 문제가 있음을 확인 하였으며, 이는 인증기준물질의 필요성을 확인시켜 주었다. 또한 BET 분석방법이 분석자의 주관에 의해 많이 좌우됨을 확인 하였다. 즉 BET 분석구간의 선택영역에 따라 CRM I의 경우 16% 까지 차이를 줄 수 있음을 확인하였는데, 이는 적정한 BET 구간의 선택을 위한 BET 매개변수 C 값과 fitting 상관계수 R 값에 대한 기준이 필요함을 확인시켜 주었다. 이러한 순회평가의 경험과 검증된 비표면적 인증물질 및 표준 절차서의 보급은 산업계에 신뢰성 있는 비표면적 측정결과를 주게 됨으로서, 일관성 있는 공정운용에 의한 품질관리, 생산성 향상, 안정성 판단 및 신제품 개발 등에 기여할 것이다.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.138-144
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• 2008

The production of the entomopathogenic and phytotoxic cyclic depsipeptide beauvericin (BEA) was studied in submerged cultures of Fusarium oxysporum KFCC 11363P isolated in Korea. The influences of various factors on mycelia growth and BEA production were examined in both complete and chemically defined culture media. The mycelia growth and BEA production were highest in Fusarium defined medium. The optimal carbon and nitrogen sources for maximizing BEA production were glucose and $NaNO_3$, respectively. The carbon/nitrogen ratio for maximal production of BEA was investigated using response surface methodology (RSM). Equations derived by differentiation of the RSM model revealed that the production of BEA was maximal when using 108 mM glucose and 25 mM $NaNO_3$.

• 한국식품저장유통학회지
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• 제15권5호
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• pp.749-753
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• 2008

청도반시 추출물로부터 라디칼 소거활성, T-bet promoter 활성, IL-4 발현 활성의 상관관계를 분석하고자 7월부터 10월까지 감을 시기별로 수확하여 분자염증 활성 여부를 확인하였다. 감의 무게는 시기가 경과할수록 무거워지면서 항산화 활성에 있어서는 감이 미숙과일수록 항산화활성이 우수하였다. 4가지의 용매로 추출한 감의 항산화 활성도 유사한 양상을 보였다. T-bet promoter 활성은 추숙이 될 수록 억제되는 양상을 보였는데, 이에 반하여 IL-4의 발현 정도는 숙성함에 따라 증가하는 것을 알 수 있었다. 이로 미루어 보아 수확시기에 따라 이러한 분자염증에 관련한 일련의 활성의 억제 효과는 감이 미숙과일수록 활성이 상승하였다.

• Carbon letters
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• 제11권3호
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• pp.169-175
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• 2010

The study describes the results of batch experiments on the removal of Reactive Yellow 15 (RY15) and Reactive Black 5 (RB5) from synthetic textile wastewater onto Activated Carbon from Walnut shell (ACW). The experimental data were analyzed by the Langmuir, Freundlish, Temkin and Dubinin-Radushkevich (D-R) models of adsorption. The experiments were carried out as function of initial concentrations, pH, temperature (303-333), adsorbent dose and kinetics. The surface area and pore volumes of adsorbent were measured by BET and BJH methods. The findings confirm the surface area (BET) is 248.99 $m^2/g$. The data fitted well with the Temkin and D-R isotherms for RY15 and RB5, respectively. The most favorable adsorption occurred in acidic pH. Pseudo-second order kinetic model were best in agreement with adsorption of RY15 and RB5 on ACW. The results indicate that walnut shell could be an alternative to more costly adsorbent currently being used for dyes removal.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 춘계 학술대회논문집
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• pp.120-124
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• 2007

Helicopters and rotary-wing vehicles encounter a wide variety of complex aerodynamic phenomena and these phenomena present substantial challenges for computational fluid dynamics(CFD) models. This investigation presents the rotor aerodynamic analysis items for the helicopter development and variety aerodynamic analysis methods to provide the better solution to researchers and helicopter developers between aerodynamic problems and numerical aerodynamic analysis methods. The numerical methods to make an analysis of helicopter rotor are as below - CFD Modelling : actuator disk model, BET model, fully rotor model,... - Grid : sliding mesh, chimera mesh / structure mesh, unstructure mesh,... - etc. : panel method periodic boundary, quasi-steady simulation, incompressible,... The choice of CFD methodology and the numerical resolution for the overall problem have been driven mostly by available computer speed and memory at any point in time. The combination of the knowledge of aerodynamic analysis items, available computing power and choice of CFD methods now allows the solution of a number of important rotorcraft aerodynamics design problems.

• 대한한방내과학회지
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• 제27권1호
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• pp.40-54
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• 2006

Objective: This study aimed to identify the different effects of GMCSBHT water-extract and ethanol-extract on Th1/Th2 differentiation by monitoring Th1/Th2 specific cytokine secretion patterns and the transcriptional activities of T-bet, GATA-3, c-maf, $INF{\gamma}$ and IL-4. Materials and Methods: Spleen cells from eight week-old BALB/c mice were cultured in GMCSBHT extracts containing medium without activation for 24 hours and with activation for 48 hours. CD4+ T cells were isolated and mRNA expression levels of $INF{\gamma}$, IL-4, T-bet, GATA-3, c-maf by RT-PCR and secretion cytokines levels of $IFN{\gamma}$, IL-4 by ELISA were analyzed. Results: GMCSBHT extracts didn't have mitogenic effects on the unstimulated CD4+ T cells. In Th1 skewed condition, GMCSBAHT water extract had no significant effects on mRNA expression levels of $IFN{\gamma}$, T-bet and c-maf, but inhibited mRNA expression levels of IL-4, GATA-3. It showed significantly increased secretion cytokine levels of $IFN{\gamma}$, but had no significant effect on secretion cytokine levels of IL-4. In Th2 skewed condition, GMCSBHT ethanol extract inhibited mRNA expression levels of $INF{\gamma}$, IL-4, GATA-3 and c-maf significantly, but had no significant effects on mRNA expression levels of T-bet. It had no significant effects on secretion cytokine levels of $INF{\gamma}$, but showed remarkable inhibitory effects on secretion cytokine levels of IL-4. Conclusion: Results suggest that on Th1/Th2 deviation, GMCSBHT water extract has both amplifying effects on Th1 differentiation and inhibitory effects on Th2, but GMCSBHT ethanol extract has stronger inhibitory effects on Th2 differentiation than on Th1.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2003년도 제31차 춘계 학술대회
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• pp.185-185
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• 2003