• Analytical Science and Technology
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• v.20 no.6
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• pp.488-495
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• 2007

A wallpaper having many surfaces in indoor is composed of various raw materials. In this study, TVOC contribution from raw materials of PVC wallpaper was evaluated by using headspace-solid phase microextraction (HS-SPME)-GC/MS. Samples were diluent, resin stabilizer, plasticizer, filler, blowing agent and PVC resin. 9 mL of each sample was put into 22 mL glass vial and they were equilibrated for 1 hour at $100^{\circ}C$. Headspace in vial was absorbed to $75{\mu}m$ Carboxen-PDMS fiber and analyzed by GC/MS. Aromatic compounds like a toluene, ethylbenzene and xylene, ketones compounds like a acetone, methoxyacetone and 2-butanone and alkane compounds like a nonane decane and undecane were identified from raw materials. And alcohol compounds like a ethanol and butanol and aldehydes were detected. TVOC emission of diluent, resin stabilizer, plasticizer, PVC resin, blowing agent and filler were $54.20{\mu}g/g$, $32.88{\mu}g/g$, $0.50{\mu}g/g$, $0.88{\mu}g/g$, $0.22{\mu}g/g$ and $0.11{\mu}g/g$, respectively. Contribution of TVOC emission of diluent, resin stabilizer and PVC resin that were concerned about add ratio were 0.708, 0.129, 0.115, respectively. In conclusion, it's necessary to reduce TVOC emission through improvement of diluent, resin stabilizer and PVC resin. Also, HS-SPME-GC/MS method which was developed in this study will be used for raw materials analysis effectively.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.443-446
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• 2008

본 연구는 과산화수소를 이용하여 디젤오염토양의 처리시 중금속 용출특성, 백연가스 발생특성 등을 평가하기 위하여 실험을 하였다. 중금속 용출속도는 반응시간 15분까지 용출이 지속적으로 증가하다가, 15분 이후 점차적으로 감소하는 경향을 보였다. 이러한 과산화수소(H$_2$O$_2$) 처리방법은 토양내 중금속 용출속도를 가속화시켜 실제 현장에서 적용될 경우 이로 인하여 지하수에 심각한 영향을 미칠 수 있으므로 ex-situ 방법 등과 같은 방법을 고려한 2차 오염에 대한 대책이 필요할 것으로 판단된다. 또한, 백연가스의 발생량은 과산화수소의 농도가 높을수록 많이 발생하는 것으로 관찰되었으며, 이는 높은 농도의 과산화수소와 유류오염토양이 급격하게 반응하기 때문인 것으로 판단된다. 백연가스 중 Hexane이 가장 높은 농도로 검출되었으며, 이 외에도 Cyclopentane, Benzene, Ethylbenzene, m,p-Xylene, Undecane 등이 많이 발생하는 것으로 나타났다. 따라서 백연가스 중에 함유된 고농도의 휘발성유기화합물(VOCs)이 주변 환경에 유해한 영향을 미칠 것으로 예상되므로 적절한 대기오염방지시설을 설치하여 제거한 후 대기로 방출하는 것이 필요하다고 판단된다.

• Journal of Environmental Health Sciences
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• v.39 no.6
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• pp.483-491
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• 2013

Objectives: Electronic cigarettes are battery powered devices that convert a nicotine-containing liquid into an inhalable vapor. The device aerosolizes nicotine so that it is readily entrained into the respiratory tract, from where it enters the bloodstream. Information on the safety of E-cigarettes is required. Methods: Seventeen articles on studies analyzing toxic substances in the liquid and gas phases of electronic cigarettes were reviewed. Results: Tobacco-specific nitrosamines, bis(2-ethylhexyl) phthalate, formaldehyde and acetaldehyde, known to be carcinogenic agents in humans or animals, were detected in the liquid and gas phases. In addition, diethyl phthalate, acetone, ethanol, cresol, xylene, propylene, styrene, triethylene glycol, tetraethylene glycol, pentaethylene glycol cis-3-hexen-1-ol, methyl cinnamate and undecane were identified in the liquid and gas phases of E-cigarettes. Propylene glycol, glycerin, 1-methoxy-2-propanol, 1-hydroxy-2- propanone, acetic acid, 1-menthone, 2,3-butanediol, menthol, carvone, maple lactone, benzyl alcohol, 2-methyl-2-pentanoic acid, ethyl mantel, ethyl cinnamate, myosamine, benzoic acid, 2,3-bipyridine, cotinine, hexadecanoic acid, and 1'1-oxybis-2-propanol were detected in the vapors of E-cigarettes. Conclusion: The hazardous compounds identified in the liquid and gas phases of E-cigarettes should be controlled for the lowest concentrations in the raw materials and production procedures.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.210-217
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• 1998

Volatile flavor components of extracts produced from the domestic angelica root, which are oleoresin and absolutes type, for tobacco flavoring materials were isolated by solvent extraction method and were analyzed by GC and GC/MSD. And then volatile flavor components of oleoresin were compared with volatiles isolated from absolutes. A total of 65 components were identified in the angelica root extracts, from which 41 components were identified in the oleoresin volatiles, contained 15 hydrocarbons, 12 alcohols, 6 acids, 10 esters and 2 miscellaneous components. The major components were hexadecanoic acid (7.79%), methyl palmitate (6.49%), ethyl palmitate (2.02 %) and sesquiterpenes and sesquiterpene alcohols, such as elemol (2.92 %), ${\gamma}$-selinene (2.19%), $\beta$-selinene (2.02%), $\alpha$-eudesmol (3.49%) and $\beta$-eudesmol (6.12%). On the other hand, volatiles of absolutes, from which 60 components were identified, contained 28 hydrocarbons, 14 alcohols, 5 acids, 10 esters and 3 miscellaneous components. The major components were hyrocarbons, such as undecane (5.11 %), dodecane (3.10%) and pentadecane (1.14 %), and $\alpha$-muurolene (1.64 %), ${\gamma}$-selinene (1.49%), $\beta$-selinene (2.12 %), $\alpha$-eudesmol (2.25%), $\beta$-eudesmol (4.87%), hexadecanoic acid (12.67%) and hexanoic acid (1.87 %).

• Journal of the Korean Chemical Society
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• v.31 no.4
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• pp.315-321
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• 1987

The ligand, 2,10-dibenzyl-4,6,8-trioxo-3,9-diaza undecane dioic acid(DTDA) for the extraction of uranium was synthesized under dry nitrogen from phenylalanine and 3-oxoglutaric acid. Extraction was performed by stirring a solution of DTDA in dichloromethane for 1 hour with an aqueous solution of $UO_2(ClO_4)_2{\cdot}6H_2O$ at various pH values and at different $DTDA/UO_2{^{2+}}$ molar ratios. Extraction efficiency reaches a maximum when the pH of the aqueous phase was ca 8.0. The extraction percentage was affected by concentration of DTDA and increases with the $DTDA/UO_2{^{2+}}$ molar ratio to complete extraction with a 4 fold excess of DTDA. The high selectivity of the DTDA for uranium was ascertained by competition experiments with other cations. The bound uranyl ion was quantitatively liberated within few minutes from the organic phase by treatment with an aqueous 1M HCI solution and DTDA was recovered very satisfactorily from the organic phase. The values of the over-all formation constants of the complex between uranyl ion and DTDA were determined to be the following : ${\beta}_1=1.20{\times}10^5\;,\;{\beta}_2=1.01{\times}10^8$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.417-422
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• 2010

Low temperature diesel combustion was achieved via a combination of late injection timing ($8.5^{\circ}$ CA BTDC to $0.5^{\circ}$ CA BTDC) and heavy exhaust gas recirculation (37% to 48%) with ultra low sulfur Swedish diesel fuel in a 1.7L common rail direct injection diesel engine. When injection timing is retarded at a certain exhaust gas recirculation rate, the particulate matter and nitrogen oxides decease simultaneously, while the hydrocarbon and carbon monoxide increase. Hydrocarbon speciation by gas chromatography using a flame ionization detector reveals that the ratio of partially burned hydrocarbon, i.e., mainly alkenes increase as the injection timing is retarded and exhaust gas recirculation is increased. The two most abundant hydrocarbon species are ethene which is a representative species of partially burned hydrocarbons, and n-undecane, which is a representative species of unburned hydrocarbons. They may be used as surrogate hydrocarbon species for performing a bench flow reactor test for catalyst development.