• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.31-34
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• 1996

In this paper, the rheological chances in sensitive materials was investigated by using QCA(Quartz Chemical Analyzer). Langmuir-Blodgett method was used to transfer sensitive material to the quartz crystals because of its facility to control that amount, and deposited sensitive material has uniformity to compare with other methods respectively. For the gas sensor using mass loading effect of quartz crystal microbalance, generally the Sauberary equation has been believed to represent the only mass loading effect. But when the organic gas is adsorpted into sensitive material, the rheological changes are occurred with different pattern as to the kinds of gases. Thus, much simpler method to identify the organic or hazard gas will be obtained by the consideration of resonant frequency changes and resonant admittance changes simultaneously.

• Membrane Journal
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• v.2 no.1
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• pp.1-20
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• 1992

Classical membrane processes like microfiltration (MF), ultrafiltration (UF) and reverse osmosis (RO) are being applied in the last years more frequently in environmental and effluent process problems. Newer technologies and developments like pervaporation (PV) and gas sepaxation (GS) recently found commercial applications in the treatment of waste waters and gas streams. The incentive here is either the clean-up from organic components to comply with federal emission regulations or the recovery of the organics for economical reasons. Processes still in their development stage are combinations of chemical reactions with membrane processes to separate and treat $SO_x$ and $NO_x$ laden waste gas streams in the clean-up of stack-gases. In this paper we will first give a short overview of the more recent developments in MF, UF and RO. This is followed by a closer look on newer technologies applied in environmental problems. The applications looked at are the recovery of organic components from solvent laden gas streams and the separation of organic volatiles from aqueous waste waters via pervaporation. Technical solutions, the advantages and disadvantages of the processes and. where possible, cost estimations will be presented.

• Journal of Hydrogen and New Energy
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• v.26 no.4
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• pp.339-346
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• 2015

The synthesis of Fischer-Tropsch (FT) oil is the catalytic hydrogenation of CO to give a range of products, which can be used for the production of high-quality diesel fuel, gasoline and linear chemicals. This studied catalyst was prepared Cobalt-supported alumina and silica by the incipient wet impregnation of the nitrates of cobalt, promoter and organic solvent with supports. Cobalt catalysts were calcined at $350^{\circ}C$ before being loaded into the FT reactors. After the reduction of catalyst has been carried out under $450^{\circ}C$ for 24h, FT reaction of the catalyst has been carried out at GHSV of 4,000/hr under $200^{\circ}C$ and 20atm. From these experimental results, we have obtained the results as following; In case of $SiO_2$ catalysts, the activity of 12wt% $Cobalt-SiO_2$ synthesized by organic solvent was about 2 or 3 times higher than the activity of 12wt% $Cobalt-SiO_2$ catalyst synthesized without organic solvent. In particular, the activity of the $Cobalt-SiO_2$ catalyst prepared in the presence of an organic solvent P was two to three times higher than that of the $Cobalt-SiO_2$ catalyst prepared without the organic solvent. Effect of Cr and Cu metal as a promoter was found little. 200 h long-term activity test was performed with a $Co/SiO_2$ catalyst prepared in the presence of an organic solvent of Glyoxal solution.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.393-397
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• 2012

In this study, an organic Rankine cycle(ORC) for gas engine waste heat recovery for industry has been constructed and a performance analysis test has been carried out. Shell & tube style heat exchanger has been equipped on an engine exhaust manifold in order to absorb heat of engine exhaust gas into the working fluid(refrigerant R134a). Under 60 kW of engine power output, about 63 kW of engine exhaust gas heat was discharged and the proportion of heat recovered was 68~73% while 43~46 kW of heat was absorbed into working fluid. Consequently rated power output of ORC was 4.6 kW while the ratio of rated power output to engine exhaust gas heat was 7.3%.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1503-1505
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• 1998

Stearic acid was deposited on surface of 9[MHz], AT-cut quartz crystal microbalance as gas sensing material using Langmuir-Blodgett(LB) technique. We measured gas response between deposited LB films and organic gas for various temperature($0{\sim}80^{\circ}C$). The resonant frequency changed due to absorbance of organic gas such as methanol and butanol gas at room temperature. However, the resonant frequency not responded to methanol gas at temperature above melting point of deposited LB films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.405-408
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• 1996

The rheological changes in sensitive materials was investigated by using QCA. Langmuir-Blodgett method was used to transfer sensitive material to the quartz crystals because of its facility to control the thickness. To develop gas sensor using quartz crystal, the rheological change of sensitive LB films were observed using the resonant resistance concept. And the rheological changes as to adsorption of organic vapours were used to analyze the response mechanism between organic vapours and sensitive LB films. We considered with resonant frequency of quartz crystal to obtain one-channel gas sensor and analytical tools of organic vapours response. In our results, we analyzed the organic vapours response by the rheological changes and mass loading as to adsorption of organic vapours.

• Elastomers and Composites
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• v.54 no.3
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• pp.188-200
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• 2019

Rubber articles contain various organic additives such as antidegradants, curing agents, and processing aids. It is important to extract and analyze these organic additives. In this paper, various extraction methods of organic additives present in rubber composites were introduced (solvent extraction, Soxhlet extraction, headspace extraction, and solid-phase microextraction), and the extracts were characterized using gas chromatography/mass spectrometry (GC/MS). Solvent and Soxhlet extractions are easy-to-perform and commonly used methods. Efficiency of solvent extraction varies according to the type of solvent used and the extraction conditions. Soxhlet extraction requires a large volume of solvent. Headspace sampling is suitable for extracting volatile organic compounds, while solid-phase extraction is suitable for extracting specific chemicals. GC/MS is generally used for characterizing the extract of a rubber composite because most components of the extract are volatile and have low molecular weights. Identification methods of chemical structures of the components separated by GC column were also introduced.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.471-477
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• 2014

Objectives: This study was conducted to evaluate area exposure of airborne dust and organic gas during entrance and shipment of chicken in poultry farms Methods: Total dust was measured with NIOSH method 0500. The volume of distributed dust and organic gas(Ammonia, TVOC, Hydrogen Sulfide) were measured using direct reading instrument. Results: The range of concentrations of total dust in area sample was $0.07{\sim}4.91mg/m^3$ during the entrance of chicks and $4.37{\sim}9.4mg/m^3$ during shipment respectively. Concentration of ammonia reached approximately 9 ppm during shipment. There was a difference of concentration of total dust in the area sample between shipment and entrance tasks. Conclusions: It was found that the development of a special intervention program by type of task should be considered for reducing respiratory health effects among poultry farmers.

• Polymer(Korea)
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• v.38 no.3
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• pp.299-306
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• 2014

ZnO pillared saponite was synthesized via a microwave hydrolysis method. To enhance interfacial compatibility between zinc oxide (ZnO) pillared saponite and poly lactic acid (PLA), ZnO pillared organic saponite was prepared by intercalation modification of cetyltrimethylammonium bromide. Moreover, PLA/ZnO pillared organic saponite nanocomposites were prepared by melting processing. The microstructure analysis of PLA/ZnO pillared organic saponite nanocomposites showed that ZnO pillared organic saponite was exfoliated and homogeneouslydispersed in PLA matrix. The property results showed that ZnO pillared organic saponite improved the mechanical properties and thermal stabilities of PLA/ZnO pillared organic saponite nanocomposites. Differential scanning calorimetry (DSC) demonstrated that ZnO pillared organic saponite restrained the appearance of cold crystallization, lowered the glass transition temperature and melting temperature of PLA, and improved the crystallinity of PLA. The results demonstrated that ZnO pillared organic saponite had a good interfacial compatibility and heterogeneous nucleation effect in PLA matrix, and also played an active role in accelerating the crystallization process of PLA.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.4
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• pp.479-485
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• 1996

Volatile organic compounds are air pollutants exhausting from industrial process, evaporation of solvent, and so on. Most of VOCs are the combustible gas of low calorific value as it is diluted by air. The systems burning such a hazardous gas need to increase enthalpy in order to increase flame stability. In this study an incinerator with reciprocating flow in the honeycomb ceramic has been used for the experiment of VOCs control. By the reciprocating flow system, the enthalpy of combustion gas is effectively regenerated into the enthalpy increases of the combustible gas through the honeycomb ceramic, which provides a heat storage. The position of the reaction zone is strongly dependent on the parameters of mixture velocity and time frequency. Flame front is changed to the point where burning velocity is coincided with burning velocity in the honeycomb ceramic. In this system it is important that flame front should be located symmetrically at the center of honeycomb ceramic for the purpose of increasing the reaction rate at one point. Peak temperature becomes higher with decreasing time frequency, at which the flow direction is regularly reversed.