• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.582-587
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• 2010

A rhodium-catalyzed reductive cleavage reaction of carbon-cyano bonds is developed using hydrosilane as a mild reducing agent. A wide range of nitriles, including aryl, benzyl, and $\beta$-hydrogen containing alkyl cyanides are applicable to this decyanation reaction. The method is also applicable to organic synthesis, in which benzyl cyanide is used as a benzyl anion equivalent and a cyano group functions as a removable ortho-directing group.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.1
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• pp.15-17
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• 2017

In carbon-11 labeling, $[^{11}C]$methyltriflate (methyltrifluoromethanesulfonate, MeOTf) is the most widely used through mild reaction condition with high yield. Strong inorganic bases, KOH, NaH and so on, were chosen to activate precursors that have phenolic alcohol as a nucleophilic moiety, because of its poor nucleophilicity. However, these catalyst can also react with radioactive intermediate, $[^{11}C]$MeOTf to afford side products. We will briefly discuss the history of the effort to increase the yield of $[^{11}C]$raclopride and suggest the alternate method for better radiochemical yield and consistency.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.588-591
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• 2004

Polyazomethine type conjugated copolymers containing phenanthridine units, poly(PZ-PTI), were synthesized by Schiff-base reaction. This new conjugated copolymer exhibited improved solubility in common organic solvents due to the presence of alkyl side chains as well as phenanthridine groups. Double layer (ITO/poly(PZ-PTI)/$Alq_3$/Mg) light emitting diode (LED) exhibited enhanced EL emission and efficiency compared to that of single layer (ITO/poly(PZ-PTI)/Mg) LED. With increasing the thickness of $Alq_3$ layer in double layer (ITO/poly(PZ-PTI)/$Alq_3$/Mg) LED the emission peak gradually shifted to the single layer (ITO/$Alq_3$/Mg) LED, confirming good hole transporting behaviour of the synthesized conjugated copolymer.

• Korean Journal of Veterinary Research
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• v.50 no.4
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• pp.259-264
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• 2010

Melamine is an organic base and a trimer of cyanamide which contains 66% nitrogen by mass, but it was sometimes illegally added to food products in order to enhance the apparent protein content for the bigger profit. Many Chinese infants and pet animals fed melamine-containing formulas suffered acute kidney failure with renal crystal formation. Fish feeds were also recently found to be contaminated with melamine. This experiment has been designed to determine whether renal crystals can be experimentally induced in crucian carp (Carassius carassius) fed melamine and cyanuric acid (each at 400 mg/kg/day for 3 days) in combination, and to compare experimentally induced crystals with those from pet animals with triazine related renal failure. The results showed that all fish developed gold brown renal crystals arranged in radial spherulites in the renal tubules, similar to those detected in the pet animals.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.140-144
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• 2006

Modern architecture after enlightenment period of Korea has been defamed indifferently before preparing devices for preservation. Many modern architecture has been underestimated by the feeling of being cultural victimized for Japan and economic logic. Other advanced countries make laws for their historic heritage with a concept for past-present-future. Also they re-create their cultural heritage to help their local economic. As the Registration System is established at july 2001, we have to find organic, positive interior space utilization methods about modern architecture. Modern architecture is private property in real using but it has historic trace. Therefore, modern architecture can be affirmative social property because it is a base of historic, cultural circumstances for local identity. The purpose of this study is to construct preservation and utilization methods of interior space for modern architecture.

• Korean Institute of Interior Design Journal
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• v.14 no.5 s.52
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• pp.193-204
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• 2005

Design took a radical turn in the 1980's, deconstructing the rigid ideology of the Modernism, often with great humor. Contemporary representable Avant-garde designers, Philippe Starck and Ron Arad brazenly borrowed from the 'historical elements' of previous styles and created bio-morphic forms with whimsical names of furniture. This study is proposed to understand the diversity of contemporary design, by comparing these two furniture designers. It also covers the common factors in contemporary furniture design, and analyzes their individual differences and similarities in design. It helps to plan the foundation of design methods for 21C, and predict and respond to the future as a reference point. Philippe Starck links Romantic Rationalism within Minimal style and Ron Arad links Deconstructivism within High-tech style but both of them pursue of Organic concept design in their furniture through the concept of humanism. They are able to establish a base of contemporary furniture design by adapting new conceptual form, and design process for the general public.

• Journal of the Korean Applied Science and Technology
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• v.15 no.2
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• pp.1-9
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• 1998

The rate constants of hydrolysis of N-tert-butyl-${\alpha}$-phenylnitrone and its derivatives have been determined by UV spectrophotometry at $25^{\circ}C$ and a rate equation which can be applied over a wide pH range was obtained. On the basis of rate equations derived and judging from the hydrolysis products obtained and general base and substituent effects, plausible mechanism of hydrolysis in various pH range have been proposed. Below pH 4.5, the hydrolysis was initiated by the protonation and followed by the addition of water to ${\alpha}-carbon$. Above pH 10.0, the hydrolysis was proceeded by the addition of hydroxides ion to ${\alpha}-carbon$. In the range of 4.5${\sim}$10.0 the addition of water to nitrone was rate controlling step.

• Earthquakes and Structures
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• v.6 no.2
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• pp.127-140
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• 2014

Laminated rubber bearing is very popular base isolation of earthquake engineering pertaining to the passive structural vibration control technologies. Rubber used in fabricating NRB and LRB can be easily attacked by various environmental factors such as oxygen, heat, light, dynamic strain, and organic liquids. Among these factors, this study carried out thermal aging test to investigate the effect of thermal aging on the mechanical properties of laminated rubber bearings in accelerated exposure condition of $70^{\circ}C$ temperature for 168 hours. The compressive-shear test was carried out to identify the variation of compressive and shear properties of the rubber bearings before and after thermal aging. In contrast to tensile strength and elongation tests, the hardness of rubber materials showed the increasing tendency dependent on exposure temperature and period. Based on the test results, the property changes of rubber bearing mainly aged by heat are quantitatively presented.

• Carbon letters
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• v.14 no.4
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• pp.228-233
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• 2013

In this work, we report in-situ observations of changes in catalyst morphology, and of growth termination of individual carbon nanotubes (CNTs), by complete loss of the catalyst particle attached to it. The observations strongly support the growth-termination mechanism of CNT forests or carpets by dynamic morphological evolution of catalyst particles induced by Ostwald ripening, and sub-surface diffusion. We show that in the tip-growth mode, as well as in the base-growth mode, the growth termination of CNT by dissolution of catalyst particles is plausible. This may allow the growth termination mechanism by evolution of catalyst morphology to be applicable to not only CNT forest growth, but also to other growth methods (for example, floating-catalyst chemical vapor deposition), which do not use any supporting layer or substrate beneath a catalyst layer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.7-11
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• 2011

Sapphire substrate was patterned by a selective chemical wet etching technique, and GaN/InGaN structures were grown on this substrate by MOVPE (Metal Organic Vapor Phase Epitaxy). The surface of grown GaN on patterned sapphire substrate (PSS) has good morphology and uniformity. The patterned sapphire substrate LED showed better light output than conventional LED that improvement 50%. We think these results come from enhancement of internal quantum efficiency by decrease of threading dislocation and increase of light extraction efficiency. Also these LED showed more uniform emission distribution in angle than conventional LED.