• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.199-199
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• 2011

The addition of a carbanion to ${\yen}{\acute{a}}{\yen}{\hat{a}}$-unsaturated carbonyl compounds is of importance in the C-C bond formation reactions for modern pharmaceuticals and organic synthesis. Recently, heterogeneous asymmetric catalysis became more attractive area of research because of the easy recovery and separation of the catalyst from the reaction system. Most of synthetic methods for heterogeneous catalysts were grafting or immobilization of homogeneous catalyst onto the solid supports. Trans-1,2-Diaminocyclohexane(DACH) and L-proline ligands have been enormously used as chiral ligands in several catalytic transformation under homogenous conditions. Our group prepared l-proline functionalized mesoporous silica was synthesized under acidic condition using a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer template (EO20PO70EO20, Pluronic P-123, BASF). Furthermore, we successfully directly synthesized trans-1,2 diaminocyclohexane functionalized mesoporous silica by using microwave method. The direct functionalization of chiral ligand into the framework of mesoporous materials is expected to be useful for the heterogeneous asymmetric catalysis. So, we adopt the direct synthesis of chiral ligand functionalized mesoporous silica by using thermal and microwave irradiation. Then, chiral ligand functionalized mesoporous silicas were applied to enantioselective asymmetric catalytic reactions.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.292-299
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• 1993

Agrobacterium tumefaciens KU12 isolated from Korea is able to induce tumors on various plants and catabolize octopine as a sole carbon and nitrogen source. A, tumefaciens KU12 contains three plasmids. Their sizes are 45.5 kb. 240 kb. and > 240 kb. respectively. For the purpose of identification of octopine type Ti plasmid, avirulent A, tumefacients A136 is transformed with plasmids isolated from KU12 by direct transformation. Transformants containing Ti plasmid were grown on AB medium containing octopine as a sole nitrogen source. The isolated strain, named KU911, contains only 240 kb plasmid. As a result of induction of crown gall and Southern hybridization with other octopine Ti plasmid pTiAch5, 240 kb plasmid named pTiKU12 was Ti plasmid.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.104-123
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• 2019

Various European countries were active rather early on in the formation and research of Korean ceramics, which are considered a representative genre of Korean art. Of these, England is especially noteworthy due to its relatively large volume of extant archival material related to the procurement of Korean ceramics in modern Britain. The material is important in that it contributes to our understanding of the formation and economic worth of these collections. Especially meaningful are the previously unknown documents dating to the period when institutions such as the British Museum and the Victoria & Albert Museum were most actively collecting Korean ceramics. These documents provide insight into the circumstances-process, prices, standards, perceptions, etc.-of procurement for the Korean ceramics now in British collections. The changes in the perception of Korean ceramics and the intention for forming such collections in modern Britain can be divided into three periods. The first, starting from the late 1870s and ending in the late 1880s, is categorized by the collectors' misguided ideal of Korean ceramics in the absence of a true understanding of the subject. During the late 1880s up until 1910, the Korean ceramics entering British collections were mostly ethnographic in nature and examples of implements used in Koreans' daily lives. Lastly, from 1910 to 1940, Korean ceramics were regarded as art objects to be collected, and Goryeo celadons formed the core of many of the British collections being assembled at the time. As for the matter of collecting standards and processes, the matter is examined through the study of three individuals who visited Korea and acquired Korean ceramics in the early 20th century. After 1910, the British started to make trips to the Far East via boat or the Trans-Siberian Express and purchase Korean ceramics during their travels. It has been confirmed that former bureaucrats were able to acquire 'good and old Goryeo ceramics' at reasonable prices from either tomb robbers or through direct visits to regions where such wares were being excavated. In addition, this study also focuses on the previously unfamiliar company Kavanaugh & Co, which made important sales and provided transport of various objects, including Korean ceramics, to its Western clients. The final part of this study examines the standards of appraisal for the Korean ceramics collected in modern Britain. The main criterion the balance between form and price of the piece. In other words, the best pieces were those that were of superior quality but acquired at the cheapest prices. British collectors particularly valued not only the Goryeo celadons favored by the Japanese but also Joseon ceramics for their innovative form, design, and technique. These standards of aesthetic and form were important factors that influenced the formation of diverse Korean ceramic collections in modern Britain.