• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.313-316
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• 2011

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.407-410
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• 2009

18~19 wt% $KMnO_4$/$SiO_2-Al_2O_3$ with Si/Al = 1/5 and 1/10, and 20 wt% $KMnO_4$/$Al_2O_3$ were prepared by solvent evaporation method. Catalytic activity of ethylene abatement over those samples were evaluated and compared under the conditions of GHSV $1125h^{-1}$, ethylene gas (ethylene 0.2%, air 99.8%, relative humidity 50%) at 30, 40, 60 and $120^{\circ}C$ using a fixed-bed reactor. $KMnO_4$/$SiO_2-Al_2O_3$ was showed better performance than $KMnO_4$/$Al_2O_3$ by 170~210% at 30, $40^{\circ}C$, and by 60% at 60, $150^{\circ}C$, respectively.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.53-58
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• 2007

In the dehydrogenation of ethylbenzene to styrene, CO2 could play a role as an oxidant to increase conversion of ethylbenzene and stability as well over TiO2-ZrO2 mixed oxide catalysts. TiO2-ZrO2 catalysts were prepared by co-precipitation method and were characterized by BET surface area, bulk density, X-ray diffraction, temperature programmed desorption of NH3 and CO2. These catalysts were found to be X-ray amorphous with enhanced surface areas and acid-base properties both in number and strength when compared to the respective oxides (TiO2 and CO2). These catalysts were found to be highly active (> 50% conversion), selective (> 98%) and catalytically stable (10 h of time-on-stream) at 600 oC for the dehydrogenation of ethylbenzene to styrene. However, in the nitrogen stream, both activity and stability were rather lower than those in the stream with CO2. The TiO2-ZrO2 catalysts were catalytically superior to the simple oxide catalysts such as TiO2 and ZrO2. The synergistic effect of CO2 has clearly been observed in directing the product selectivity and prolonging catalytic activity.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1345-1348
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• 2012

• Korean Journal of Pharmacognosy
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• v.31 no.2
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• pp.252-255
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• 2000

In order to screen new radical scavenging principle which is expected to be antiaging drug lead, we have investigated 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the marine microalgae, greenalgae(10 speices), diatom (10 speices) and blue-green algae (10 speices). The significant activities$(IC_{50}:\;<100\;{mu}g/ml)$ were observed in 4 species of green algae (MA002, 006, 009, 010), 1 species of diatom (MA015) and 5 species of blue-green algae (MA017, 018, 019, 024, 025). Within the scope of family tested, MA009 $(IC_{50}:\;=78\;{mu}g/ml)$, MA015 $(IC_{50}:\;=38\;{mu}g/ml)$ and MA019 $(IC_{50}:\;=41\;{mu}g/ml)$ displayed the most significant activity. Among the marine microalgae tested at family level, cyanophycean blue-green algae was shown to be the most active family on screening of new bioactive compounds.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.214-221
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• 2020

BACKGROUND: The demand for pesticide registration has kept increasing for minor crop cultivation in greenhouse since Positive List System (PLS) has been launched. Thus, much study on the evaluation of pesticide residues in minor crops is required to examine the demand. In this study, we evaluated residues of acetamiprid, boscalid, imidacloprid and pyraclostrobin in the minor crop mustard green to provide the potential data for their registration. METHODS AND RESULTS: Pesticide granule formulations of acetamiprid, boscalid, imidacloprid and pyraclostrobin were incorporated into soil and applied onto field soil surface at rates of 3 kg/10a, 6 kg/10a, 3 kg/10a and 6 kg/10a, respectively. The pesticides were also applied at the two times higher than the rates to compare the residues between the application rates. Mustard green seeds were sown 1 day after pesticide application and cultivated under greenhouse conditions. LC/MS/MS analyses coupled with a modified QuEChERs method were employed for determination of the pesticides in plant samples. The method limits of quantitation (LOQ) of the pesticides were 0.01 mg/kg, and the matrix calibration curves of the pesticides showed linearity with coefficient values of determination (r²) greater than 0.995. The average recovery values of the pesticides fortified in control samples at rates of LOQ and 10LOQ ranged from approximately 77.5% to 101.2% with relative standard deviation values lower than 14%. The pesticides in the mustard green samples cultivated for 53 days after sown were determined to be lower than the LOQ level. CONCLUSION: Acetamiprid, boscalid, imidacloprid and pyraclostrobin were found at a level lower than 0.01 mg/kg in the minor crop mustard green. Thus, their residues in mustard green would not violate PLS under greenhouse conditions.

• Journal of Adhesion and Interface
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• v.11 no.2
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• pp.76-83
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• 2010

The extensive use of fossil resources over the past century resulted in dwindling supply and surging price of oil and it is strongly suspected that irreversible global climate change might be due to carbon dioxide emitted from combustion of fossil carbons. With this regard, much attention is recently paid to renewable and sustainable resources as alternatives to petroleum. In this review, we considered a range of efforts to replace petroleum-derived chemicals, particularly adhesive materials with renewable and sustainable plant-based biomass feedstock.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3410-3414
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• 2013

Atom-economical esterification is of great importance in green chemistry. In this work, we demonstrated the catalyst and additive free esterification of alcohols by their reaction with 2-acyl-4,5-dichloropyridazin-3(2H)-ones without solvent at $100^{\circ}C$. Aliphatic and aromatic alcohols were converted into the corresponding esters in good to excellent yields. It is noteworthy that the reaction is solvent-free, atom-economic, easy-workup, and rapid and that the process is inexpensive.

• Analytical Science and Technology
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• v.17 no.6
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• pp.476-480
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• 2004

A simple, rapid, reproducible and selective UV-Visible spectrophotometric method has been developed for determination of germanium in a week acid medium (pH = 3.0) in the presence of mandelic acid (MA) and malachite green (MG). A single extraction in chlorobenzene was used for the analysis. The germanium-MA ion association complex exhibits an absorption maximum at ${\lambda}_{max}=618nm$ with MG as counter ion and has an apparent molar absorptivtity of $1.313{\times}10^5L\;mol^{-1}\;cm^{-1}$. The values obtained by this UV-Visible spectrophotometric method are in good agreement with the values from inductively coupled plasma-mass spectrometer analysis.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.694-696
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• 2010

We have synthesized boron (or phosphorous) doped silicon nanoparticles (Si-NPs) by a solution process. The surfaces of the Si-NPs were terminated with various alkyl groups to form a protecting layer. The Si-NPs were characterized by UV-Vis, PL, FTIR, and NMR. Through a microwave sintering process, the crystalline thin films of the Si-NPs were prepared by removing the surface alkyl groups. The TEM and SEM images reveal that contiguous films as large as $200{\mu}m$ in diameter were formed with a cubic structure. The electrical conductivity of the Si film was controlled by a doping type.