• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.219-224
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• 2011

The new MPV type reagent, Al-trifluoromethanesulfonyldiisobutylalane ($DIBAO_3SCF_3$), has been prepared and its reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined, and compared its reactivity with that of Al-methanesulfonyldiisobutylalane ($DIBAO_3SCH_3$) in order to understand the fluorine-substituent effect on its reactivity. In general, the reactivity of $DIBAO_3SCF_3$ appears to be much higher than that of $DIBAO_3SCH_3$, apparently due to the acidity increase by the electron-withdrawing fluorine-substituent. The reagent reduced aldehydes and ketones readily, but showed a perfect selectivity in the reduction of $\alpha,\beta$-unsaturated aldehydes and ketones to produce the corresponding allylic alcohols in an absolutely 100% purity. In addition, the reagent achieved the regioselective cleavage of phenyl- or/and alkyl-substituted epoxides to the less substituted alcohols in a perfect regioselectivity. Moreover, the reagent also showed an high stereoselectivity in the reduction of substituted cycloalkanones to produce the thermodynamically more stable alcohol epimers exclusively.

• Progress in Superconductivity and Cryogenics
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• v.21 no.2
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• pp.45-49
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• 2019

This paper reports comparison between analytic and numerical simulation approaches for calculation of screening current and screening current induced field in a high temperature superconductor magnet. Bean slab model is adopted to calculate screening current and SCF analytically, while the finite element method numerically. A case study of screening current and SCF calculation are conducted with a magnet, a 7 T 68 mm cold-bore multi-width no-insulation GdBCO magnet built and tested by Massachusetts Institute of Technology Francis Bitter Magnet Laboratory. In this study, we assume the magnet is dunked in liquid nitrogen at 77 K. Furthermore, the simulation results are compared in terms of computation time and accuracy. Finally, discussion on the different methods together with the comparison between the calculations and experiment is provided.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.844-844
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• 2005

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.24-24
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• 2009

• Bulletin of the Korean Chemical Society
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• v.29 no.12
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• pp.2419-2422
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• 2008

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.177.1-177.1
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• 2001

• Journal of Microbiology
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• v.44 no.6
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• pp.641-648
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• 2006

We previously reported that Skp1, a component of the Skp1-Cullin-F-box protein (SCF) complex essential for the timely degradation of cell cycle proteins by ubiquitination, physically interacts with Bfa1, which is a key negative regulator of the mitotic exit network (MEN) in response to diverse checkpoint-activating stresses in budding yeast. In this study, we initially investigated whether the interaction of Skp1 and Bfa1 is involved in the regulation of the Bfa1 protein level during the cell cycle, especially by mediating its degradation. However, the profile of the Bfa1 protein did not change during the cell cycle in skp1-11, which is a SKP1 mutant allele in which the function of Skp1 as a part of SCF is completely impaired, thus indicating that Skp1 does not affect the degradation of Bfa1. On the other hand, we found that the skp1-12 mutant allele, previously reported to block G2-M transition, showed defects in mitotic exit and cytokinesis. The skp1-12 mutant allele also revealed a specific genetic interaction with ${\Delta}bfa1$. Bfa1 interacted with Skp1 via its 184 C-terminal residues (Bfa1-D8) that are responsible for its function in mitotic exit. In addition, the interaction between Bfa1 and the Skp1-12 mutant protein was stronger than that of Bfa1 and the wild type Skp1. We suggest a novel function of Skp1 in mitotic exit and cytokinesis, independent of its function as a part of the SCF complex. The interaction of Skp1 and Bfa1 may contribute to the function of Skp1 in the mitotic exit.

• Journal of the Korean Chemical Society
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• v.47 no.4
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• pp.325-333
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• 2003

The geometrical parameters, vibrational frequencies, and relative energies for 1,2-, 1,3-dioxetanes, and 1,3-cyclodisiloxane have been investigated using high level ab initio quantum mechanical techniques with large basis sets. The geometries have been optimized at the self-consistent field(SCF), the single and double excitation configuration interaction(CISD), the coupled cluster with single and double excitation(CCSD), and the CCSD with connected triple excitations[CCSD(T)] levels of theory. The highest level of theory employed in this study is TZ2P CCSD(T). Harmonic vibrational frequencies and IR intensities are also determined at the SCF level of theory with various basis sets and confirm that all the optimized geometries are true minima. Also zero-point vibrational energies have been considered to predict the dimerization energies for 1,2- and 1,3-isomers.

• Korean Journal of Remote Sensing
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• v.33 no.4
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• pp.401-410
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• 2017

Estimation of snow depth using optical image is conducted by using correlation with Snow Cover Fraction (SCF). Various algorithms have been proposed for the estimation of snow cover fraction based on Normalized Difference Snow Index (NDSI). In this study we tested linear, quadratic, and exponential equations for the generation of snow cover fraction maps using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite in order to evaluate their applicability to the complex terrain of South Korea and to search for improvements to the estimation of snow depth on this landscape. The results were validated by comparison with in-situ snowfall data from weather stations, with Root Mean Square Error (RMSE) calculated as 3.43, 2.37, and 3.99 cm for the linear, quadratic, and exponential approaches, respectively. Although quadratic results showed the best RMSE, this was due to the limitations of the data used in the study; there are few number of in-situ data recorded on the station at the time of image acquisition and even the data is mostly recorded on low snowfall. So, we conclude that linear-based algorithms are better suited for use in South Korea. However, in the case of using the linear equation, the SCF with a negative value can be calculated, so it should be corrected. Since the coefficients of the equation are not optimized for this area, further regression analysis is needed. In addition, if more variables such as Normalized Difference Vegetation Index (NDVI), land cover, etc. are considered, it could be possible that estimation of national-scale snow depth with higher accuracy.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1108-1114
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• 2007

Twenty eight non-lactating and non-pregnant adult Serra da Estrela ewes, ranging in body condition score (BCS) from 1 to 4 were used to study the relationships between BCS, live weight (LW), body composition and fat partition. Ewes were slaughtered and their kidney knob and channel fat (KKCF), sternal fat (STF) and omental plus mesenteric fat (OMF) were separated and weighed. Left sides of carcasses as well as the respective lumbar joints were then dissected into muscle, bone and subcutaneous (SCF) and intermuscular fat (IMF). The relationship between LW and BCS was studied using data from 1,396 observations on 63 ewes from the same flock and it was found to be linear. Regression analysis was also used to describe the relationships among BCS and/or LW and weights (kg) and percentages in empty body weight (EBW) of dissected tissues. The prediction of weights and percentages in EBW of total fat (TF) and of all fat depots afforded by BCS was better than that provided by LW. Only the weight of muscle and the percentage of bone in the EBW were more efficiently predicted by LW than by BCS. IMF represented the largest fat depot with a BCS of 1 and 2, whereas SCF was the most important site of fat deposition with a BCS of 3 and 4. Allometric coefficients for each fat depot in TF suggest that the fat deposition order in ewes from this breed is: IMF, OMF, SCF and KKCF. Results demonstrate that BCS is a better predictor than LW of body reserves in this breed and that LJ is a suitable anatomical region to evaluate BCS.