• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1308-1314
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• 1999

The effects of modified atmosphere(MA) packaging and coating on the quality of mushroom (Agaricus bisporus) were investigated. Whole mushrooms(100 g) were packed with polyvinyl chloride(PVC) film wrap, PD941 and PD961 film bags and were stored in a chamber at $12^{\circ}C$ and 80% RH for 6 days. Gas composition of packages, respiration rate, weight loss, color and maturity index of MA packaged mushrooms were examined. The wrap packaged mushrooms showed different level of internal $CO_2$ concentrations among water washed, chitosan coated and $CaCl_2$ coated subgroups significantly at 5% level. The maximum $CO_2$ concentration of PD941 and PD961 packages for all coated showed $4.1{\sim}4.7%$ and $10.4{\sim}11.7%$, respectively, for the first day. PD961 package showed the lowest $O_2$ concentration compared to other groups. There were no significant respiration rate differences between wrap packed and PD941 packaged. Respiration rate of water washed. chitosan coated and $CaCl_2$ coated in PD961 packaged was 192 mg, 226 mg and 245 mg, respectively. Maturity index of PD961 packaged were not significantly different among the water washed, chitosan and $CaCl_2$ coated packages. Chitosan coating showed a negative effect on color change of mushrooms. The weight loss of 961 packaged was lower $(7.0{\sim}8.0%)$ that those of wrap packaged and PD941 packaged.

• Proceedings of the Korean Magnestics Society Conference
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• 1991.05a
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• pp.103-104
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• 1991

• Proceedings of the KIEE Conference
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• 2008.04b
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• pp.174-175
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• 2008

초고압 변전소의 주요설비인 가스절연개폐장치(GIS: Gas Insulated Switchgear)의 신뢰도를 높이기 위해서는 절연체 내부에서 발생하는 부분방전을 사전에 진단하여 예방을 하는 것이 중요하다. 현재 이에 대한 진단장치 개발이 이루어지고 있으며 GIS On-line System 장치 및 휴대용 진단장비가 국내에서 제작되고 있으나 On-line System은 고가의 비용이 들고 휴대용 진단장비는 상시감시가 어렵다는 단점을 가지고 있다. 이러한 단점을 보완하기 위해서 본 연구내용에서는 저가이면서 상시 PD 감시능력을 가진 PD 카운터에 대해 설명하고 GIS 현장에 실제 적용한 자료와 휴대용 진단장비와 함께 비교 적용한 자료를 가지고 PD 카운터의 특성을 확인하는데 역점을 두었다.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.541-548
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• 2014

This study was performed to obtain high conversion efficiency of $C_7H_8$ using non-thermal plasma and metal-supported catalyst. Adsorption-desorption characteristics of toluene was performed using 4A type (Zeolite) filled in a concentration reactor. Through this test, it was found that the concentration reactor has 0.020 g/g of adsorption capacity (at ambient temperature and pressure) and 3,600 ppm of desorption property at $150^{\circ}C$ (with in 20 min). In case of developed catalyst, toluene decomposition rate of Pd-AO (Pd coated catalyst) was better than Pd/Cu-AO and Pd/Ag-AO (Pd/Ag composite metal catalyst). Developed non-thermal plasma system was obtained flame amplification effect using injection process of desorbed tolune, and 98% of removal efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.100-103
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• 2004

In this paper, BP learning algorithm is studied to apply as a PD source classification in GIS specimens. For occurred partial discharge, three defected models are made; floating particle, surface discharge of spacer, needle to plane. And PD data for discrimination were acquired from PD detector. And these data making use of a computer-aided discharge analyser, statistical and other discharge parameters is calculated to discrimination between different models of discharge sources. And also these parameter is applied to classify PD sources by neural networks. Neural Networks has good recognition rate for three PD sources.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.139-142
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• 1990

A gas sensor, comprised of both ZnO and $PdCl_2$ powders, has been developed to sense the CO gas of low concentration (100 ppm). When the weight ratio of ZnO/$PdCl_2$ element sintered at $600^{\circ}C$ was 99.5/0.5, the maximum sensitivity to CO gas was obtained at the operating temperature of $200^{\circ}C$. Also, the response characteristics of this element were examined, and then the response time was decreased from 90 to 45 sees, with operating temperature increase in the range of $100-400^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.663-663
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• 2013

We prepared Cu oxides, and Ni and Pd-TiO2@SiO2 core-shellnanostructures, and tested their CO oxidation performances by temperature-programmed mass spectrometry. We found the starting temperatures of CO oxidation are around $200^{\circ}C$ and $300^{\circ}C$ for Ni and Pd-TiO2@SiO2 nanostructures, respectively. Cu oxides are cubes with 50~200 nm with, prepared with different concentrations of NaOH and ascorbic acid. For the core-shell structures, we prepared 100 nm SiO2 spheres, first coated the surface with TiO2 precursor, and then coated with Ni and Pd. Their characteristics are further examined by scanning electron microscopy, optical microscope, FT-IR, and UV-Vis absorption spectroscopy.

• Bulletin of the Korean Chemical Society
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• v.19 no.9
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• pp.942-947
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• 1998

The >$^13C$ NMR spectrum of >$^13CO$ adsorbed on Pd particles varies dramatically depending on dispersion. The spectrum of highly dispersed Pd particles supported on silica is a powder pattern ∼800 ppm wide with a first moment of 410 ppm. A low dispersion sample has a motionally narrowed line centered at 750±30 ppm and only ∼85 ppm full width at half height (FWHH). Over several years, high dispersion samples show an increase in the intensity near 750 ppm. These observations are interpreted as an increase of mobile bridging CO on high dispersion Pd surfaces of particles which resulted from smoothing of the metal particle surfaces in the presence of CO.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.878-883
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• 1998

The methane combustion reaction was conducted over Pb-ZSM-5 catalysts. ZSM-5 synthesized at low temperature and atomospheric pressure was used as a support. The change of methane conversion with $SiO_2/Al_2O_3$ molar ratio was tested. The methane conversions of the synthesized Pb-ZSM-5 catalyst was compared with those of a commercial Pd-ZSM-5(PQ Co.) and $PdO/{\gamma}-Al_2O_3$. The methane conversion increased with the decrease in $SiO_2/Al_2O_3$ molar ratio. The combustion rate of methane also increased with the decrease in $SiO_2/Al_2O_3$ molar ratio. The synthesized Pb-ZSM-5 showed better methane conversion than that of the commercial one. It is found that a crucial factor in methane combustion reaction is oxygen adsorption strength on the catalysts.

• Korean Journal of Materials Research
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• v.28 no.6
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• pp.365-369
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• 2018

We perform density functional theory calculations to study the CO and $O_2$ adsorption chemistry of Pt@X core@shell bimetallic nanoparticles (X = Pd, Rh, Ru, Au, or Ag). To prevent CO-poisoning of Pt nanoparticles, we introduce a Pt@X core-shell nanoparticle model that is composed of exposed surface sites of Pt and facets of X alloying element. We find that Pt@Pd, Pt@Rh, Pt@Ru, and Pt@Ag nanoparticles spatially bind CO and $O_2$, separately, on Pt and X, respectively. Particularly, Pt@Ag nanoparticles show the most well-balanced CO and $O_2$ binding energy values, which are required for facile CO oxidation. On the other hand, the $O_2$ binding energies of Pt@Pd, Pt@Ru, and Pt@Rh nanoparticles are too strong to catalyze further CO oxidation because of the strong oxygen affinity of Pd, Ru, and Rh. The Au shell of Pt@Au nanoparticles preferentially bond CO rather than $O_2$. From a catalysis design perspective, we believe that Pt@Ag is a better-performing Pt-based CO-tolerant CO oxidation catalyst.