• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.624-629
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• 2010

The synthesis and evaluation of a novel calix[4]arene-based fluorescent chemosensor 1 for the detection of I. is described. The fluorescent changes observed upon addition of various anions show that 1 is selective for I. over other anions. Addition of I. results in ratiometric measurements with 1 : 1 complex ratio.

• Korean Journal of Materials Research
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• v.12 no.10
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• pp.825-830
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• 2002

The growth rate of solid grains in TiC-XC-2vol% and TiC-XC-30vo1% Ni cermets, where X=Zr, W or Mo, was fitted to an equation of the form $d^3$-$do^3$=Kt. The grain growth behavior during liquid phase sintering at 1673K decreased markedly with addition of $Mo_2$C or WC and increased with addition of ZrC. The contiguity ratio was greater in the alloys with smaller growth rate constant and decreased with increasing Ni content in the $TiC-Mo_2$C-Ni cermet. The grain growth mechanism could be explained by the effect of contiguous grain boundaries in restricting the overall grain growth.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1155-1158
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• 2010

Microwave-assisted Michael reaction between EMME and various amines such as diphenylamine, 4-methyl-N-phenylbenzenamine, N-phenylnaphthalen-1-amine, dihexylamine, diisopropylamine, and 4-nitrobenzenamine were described. Solvent-free conditions on alumina as solid support in the presence of $K_2CO_3$ catalysts gave moderate to good yields (55 - 93%) of diethylmalonate analogues having enamine moieties under focused microwave irradiation.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.36-39
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• 2004

In this study, effects of fluosilicate salt based chemical admixture(MZ) on the watertightness and hardening properties of concrete were investigated. Mix proportions for experiment were modulated at 0.55 of water to cement ratio and addition amount of MZ to $2.0\%$ at intervals $0.5\%$. Compressive strength, porosity and microstructure of hardened concrete cured at several days were executed to evaluate watertightness and hardening properties. It is ascertained that watertightness and hardening properties of concrete could be improved by an adequate addition of fluosilicate salt based chemical admixture.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.258-261
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• 2006

The addition of zeolite particles enhances the stability of mRNA molecules in a cell-free protein synthesis system. When $20{\mu}g/{\mu}L$ of zeolite (Y5.4) is added to a reaction mixture of cell-free protein synthesis, a substantial increase in protein synthesis is observed. The stabilizing effect of zeolite is most dearly observed in an in vitro translation reaction directed by purified mRNA, as opposed to a coupled transcription and translation reaction. Upon the addition of zeolite in the in vitro translation reaction, the life span of the mRNA molecules is substantially extended, leading to an 80% increase in protein synthesis. The effect of zeolite upon the mRNA stability appears be strongly related to the cation exchange (potassium to sodium) reaction. Our results demonstrate the possibility of modifying this biological process using heterogeneous, non-biological substances in a cell-free protein synthesis system.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.189-189
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• 2015

In this study, the corrosion resistance and adhesion of electrophoretic paint (E-paint) were studied on AZ31 magnesium alloy pretreated in cerium chemical conversion coating solutions with the addition of various ethanol concentrations. It was found that with increasing ethanol concentration from 0 to 90 percent can decrease the formation of $Mg(OH)_2/MgO$ and increase the formation of nano-crystalline cerium oxides on the coating. Both corrosion resistance and adhesion of E-painted AZ31 increased with increasing ethanol concentration. The best E-paint sample was observed on the sample pretreatment in cerium chemical conversion coating solution with the addition of 80 percent of ethanol. This sample showed an excellent adhesion without paint detached after water immersion test for 500 h at $40^{\circ}C$, and only a few blisters observed at the near scratched sites after 1000 h salt-spray test.

• Environmental Analysis Health and Toxicology
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• v.18 no.3
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• pp.183-191
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• 2003

Although the variety and quantities of chemicals used have been increasing, no management strategies have been developed for these chemicals in our country. Therefore, it is important to identify the hazardous characteristics of chemicals and establish reasonable and effective management plans for them. However, because insufficient resources are available to evaluate all aspects of many varieties of chemicals, studies on suitable chemical ranking and scoring (CRS) system should be performed to ensure effective screening of priority chemicals.. In addition, because most CRS systems have their own goals, it is impossible for only one generic system to be consistent with all the uses that have been developed. Therefore, priority systems should be developed with specific and clearly defined purposes in our nation. In this study, we investigated and discussed exist-ing CRS systems, and proposed several elements and principles when designing CRS systems. First of all, the system should have clearly defined goals, keep neutral, and employ simple methods. In addition, researchers need to perform sensitivity analysis to find the main variables responsible for uncertainties and use the tiered approach to compose the effective management strategies for chemicals.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.566-568
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• 2003

The phosphor $CaTiO_3:Pr^{3+}$ attracts much attention as a low-voltage red phosphor because of its good chromaticity and intrinsic conductivity. The addition of Ga into this CaTiO₃:Pr led the luminance intensity to greatly enhance without the change of the wavelength for the electronic transition and the peak shape of it. The increase of the recombination rate of electron-hole pairs through the Ga ion doping, which was expected to play a role of a hole-trap center, is proposed to be one of the reasons for the enhancement of the cathodoluminescence intensity.

• Archives of Pharmacal Research
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• v.9 no.2
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• pp.63-73
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• 1986

The use of biodegradable polymetric materials as drug carriers is a relatively new dimension in polymeric drug delivery systems. A number of biodegradable or bioerodible polymers, such as poly(lactic/glycolic acid) copolymer, poly($\alpha$-amino acid), polyanhydride, and poly (ortho ester) are currently being investigated for this purpose. These polymers are useful for matrix and reservoir-type delivery devices. In addition, when chemical functional groups are introduced to the biodegradable polymer backdone, such as poly (N-(2-hydroxypropyl) methacrylamide), the therapeutic agent can be covalently bound directly or via spacer to the backbone polymer. These polymer/drug conjugates represent another new dimension in biodegradable polymeric drug delivery systems. In addition, examples of biodegradable polymeric durg delivery systems currently being investigated will be discussed for the purpose of demonstrarting the potential importance of this new field.

• Macromolecular Research
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• v.11 no.1
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• pp.69-72
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• 2003

A homopolymer having pendent t-Boc-protected quinizarin moieties has been prepared for patterned fluorescence images. The homopolymer P(t-BQN (2-norbornenylmethyl di-tert-butoxycarbonylquinizarin)) 5 was prepared by palladium-catalyzed addition polymerization. The t-Boc-protecting groups of the polymer were efficiently removed during chemical amplification process and revealed original properties of quinizarin, allowing patterned fluorescence images in the polymer film.