• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.1
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• pp.27-32
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• 2003

To understand the chemical structure of sewer sludge in comparison with commercial compost and charcoal used as a soil improver, it was carried out to analyse their ash contents and metal ions, and to elucidate the chemical structure of their residuals after a sequential treatment of alcohol-benzene(1:2) extraction in Soxhlet, 3% HCl reflux and 79% H₂SO₄ hydrolysis, using CHNS analyzer and solid C-13 NMR spectrometer. The results obtained were as follows: 1. Ash content of sludge was about 46% that is higher than those of compost (17%) and charcoal (4%). 2. The residual of sludge after a sequential treatment of HCl and H₂SO₄ hydrolyses had high ash content about 23%, too. 3. The sludge seems to be suitable to the soil improver because the content of heavy metal ions in sludge was near the compost and below the organic fertilizer standard. 4. Elemental composition of sludge residual after HCl-H₂SO₄ hydrolyes was C/sub 56/H/sub 91/O/sub 12/N₂S = (C/sub 6/H/sub 10/O/sub 5/)/sub 7/(C/sub 6/H₄)/sub 7/C₂H/sub 43/O₂N₂S, similar to C/sub 103/H/sub 122/O/sub 33/N/sub 6/S = (C/sub 6/H/sub 10/O/sub 5/)/sub 6/(C/sub 6/H₄)/sub 10/C/sub 7/H/sub 22/O₃N/sub 6/S of compost. 5. The sludge residual had proved to have both considerable aliphatic and aromatic groups, but the compost residual to have mainly aliphatic groups and the charcoal to have mainly aromatic groups, through the peak analysis of solid C-13 NMR charts. 6. So, the sewer sludge is proved to have a considerable amount of aromaticity like in woody biomass containing lignin.

• Analytical Science and Technology
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• v.13 no.3
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• pp.357-367
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• 2000

The polycyclic aromatic hydrocarbon (PAH) content in sewage sludge and in farm soils were determined by gas chromatography linked to mass spectrometry (GC/MS) with use 2-ethylantracene as internal standards. Twelve PAH were identified in both sludges with naphthalene ($0.78{\mu}g/g$) being the most predominant in industrial sludge and pyrene ($0.26{\mu}g/g$) in municipal sludge. The total PAR content in industrial sludge and in municipal sludge were $1.74{\mu}g/g$ and $1.19{\mu}g/g$ respectively. PAH were contained in paddy soils and the concentration were very low in the range of $0.01-0.04{\mu}g/g$. The total PAH content in industrial and in municipal sludge were about 9.2 times and 6.3 times greater than in paddy soils ($0.19{\mu}g/g$).

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1349-1358
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• 2018

In addition to responding to the environmental pollution caused by fossil fuels, the enforcement of Renewable Fuel Standard(RFS) system has increased the utilization of renewable energy such as refined fuels oil. The by-product fuel oil(No. 2) and the refined fuel oil(reduced-pressure) are strictly regulated by the domestic legislation and the chemical property changes of the refined fuel oil(reduced-pressure) mixed with the by-product fuel oil(No. 2) were analyzed. As a result of analyzing the physical properties of refined fuel oil(reduced pressure) obtained by mixing 1 : 1 of by-product fuel oil(No. 2), it satisfied the quality standards stipulated by the domestic Enforcement Decree of the Wastes Control Act. However, the results of the additional tests related to the fuel showed a high aromatic content. The high content of aromatic in a fuel is likely to cause the soot and ehaust emission gas during the combustion of the used equipment.

• Journal of the Korean Society of Tobacco Science
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• v.10 no.2
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• pp.109-116
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• 1988

Oriental tobacco (KA 101) was transplanted from Mar. 25 to May 5 with 10 days interval in 1984 and 1985, and its agronomic characteristics, chemical properties ware compared to determine the Proper transplanting time of aromatic tobacco In Korea. As the transplanting was delayed, days to flowering of plant was shortened, length and width of largest leaf, leaf area index tended to decrease. Yield was highest for the Apr. 5th transplanting followed by Mar. 25th planting, then decreased as the planting date was delayed. Quality by price decreased as the transplanting was delayed later than Apr. 25. Delaying transplanting increased nicotine, total nitrogen and ash content, but decreased reducing sugar and petroleum ether extract of cured leaves, The content of volatile organic acids such as 3-methyl pentanoic acid was lower when it was transplanted later than Apr. 25th. Neophytadiene content increased as the transplanting was delayed, but there were no trends with the content of alcohols, aldehydes esters and ketones. Several quality indices including the ratio between the content of volatile organic acids plus petroleum ether extract and ash content plus pH was higher for the Apr. 5th transplanting.

• Bulletin of the Korean Chemical Society
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• v.20 no.2
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• pp.159-162
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• 1999

Three different chemical compositions of total paraffin, total naphthene, total aromatic content in naphtha have been successfully analyzed using FT-Raman spectroscopy. Partial least squares (PLS) regression has been utilized to develop calibration models for each composition from Raman spectral bands. The PLS calibration results showed Blood correlation with those of gas chromatography (GC). Using PLS regression, the spectral information related to each composition has been successfully extracted from highly overlapped Raman spectra of naphtha.

• Elastomers and Composites
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• v.56 no.3
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• pp.152-163
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• 2021

Liquid butadiene rubber (LqBR) is used as a processing aid and plays a vital role in the manufacture of high-performance tire tread compounds. In this study, center-functionalized LqBR (C-LqBR) was polymerized with different vinyl content via anionic polymerization. The effects of the vinyl content on the properties of the compounds were investigated by partially replacing the treated distillate aromatic extract (TDAE) oil with C-LqBR in silica-filled rubber compounds. C-LqBR compounds showed a low Payne effect and Mooney viscosity regardless of the vinyl content, because of improved silica dispersion due to the ethoxysilyl group. As the vinyl content of C-LqBR increased, the optimum cure time (t₉₀) increased owing to a decrease in the number of allylic hydrogen. Moreover, the glass transition temperature (T_g) of the compound increased, and snow traction and abrasion resistance performance decreased, whereas wet grip improved. The energy loss characteristics revealed that the hysteresis attributed to the free chain ends of C-LqBR was dominant.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.7-12
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• 1988

This study was conducted to establish the most appropriate transplanting time which can attribute to increase of aromatic substances in tobacco variety, Hyangcho, maintaining its original aroma. The highest content of total alkaloid, total nicotine and total nitrogenous compounds were observed in the late transplanting time such as July 5, showing 4.16%, 3.83% and 3.68%, respectively. However, the petroleum ether extract was highest in the early transplanted one such as April 5, showing 5.77% and total sugar content, 12% in April 20. The content of petroleum ether extract decreased as the transplanting time delayed. The early transplanting of Hyangcho on April 20 under vinyl mulching showed the increase of fatty acid content, but the decrease of non-volatile organic acids such as malic and citric acids than those of the conventional transplanting time on March 5. The earlier transplanting time also increased the content of volatile acids such as 2,3-methylbutanoic acid and 3-methyl-pentanoic acid, which seem to be related to tobacco aroma.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.75-84
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• 2018

This study investigated the pollution status of polycyclic aromatic hydrocarbons (PAHs) such as benzopyran, which is a harmful substance, in convergence herbal pills distributed in Seoul. During 2010 ~ 2013, 31 items and 93 samples were collected from the herbal medicines vendors in Seoul, and the samples were extracted, filtered, concentrated, and then spun out with SPE (Sep-pak florisil) and concentrated again and analyzed by liquid chromatography. The results of the analysis showed that the average contents of PAHs were below $10{\mu}g/kg$, and the PAHs were lower than those of daily life exposure, and MOEs was evaluated as safe to a negligible level. In the future, comparative fusion studies on the harmful substances of medicinal pills and food pills are needed.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.577-588
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• 1998

Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion and, in urban area atmosphere, are mainly traffic or heating in origin. Size-segregated aerosol samples were collected on the Eixth story of Shinchon on the Yonsei campus, using a high-volume cascade impactor, between August 1994 and September 1995. Ten PAHs were analyzed by GC/MSD. The size distribution of PAH-containing particulates followed approximately a log-normal relationship with the majority of PAH content associated with particles below 3.0mm. PAHs concentration in submicron particles increased during the winter months. The Mass Median Diameter (MMD) value of annual particulates in the heavy traffic area of Shinchon shows about 1.6 pm. The MMD values of air particulate in winter were the lowest values and similar to that in summer, while MMD values of seasonal PAHs were generally lower than 1.0 pm. Among the PAHs, MMD values of PAHs with the more than 5 benzen ring were averagely lower than those with 4 benzin rings. Especially MMD's of dibenzo (a, h) anthracene in winter was clearly lower than in summer. This reason may be caused by fuels used for heating. In this area, 50∼80% PAHs mass was particles smaller than 1.0mm aerodynamic diameter in size range, and the MMD values of PAHs lower than those of other country's area.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_3
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• pp.113-119
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• 2001

Surface sediments(0~5 cm) were sampled from 22 stations in Ulsan Bay, one of the most highly industrialized regions in Korea, in November 2000. The sediment samples were analyzed for their polycyclic aromatic hydrocarbon(PAH) content using a gas chromatography coupled to a mass spectrometer detector(GC/MSD). The total PAH concentrations in the sediments varied from 14 to 7108 ng/g dry weight with a mean value of 1052 ng/g dry weight. The level of carcinogenic PAHs ranged from 6 to 2396 ng/g dry weight with a mean value of 433 ng/g dry weight. The highest PAH concentrations in the sediments from Ulsan Bay were found at Station U8, whereas the lowest levels were observed at Stations U2 and U 17. The PAH distribution exhibited a decreasing gradient from the inner basin to the outer bay. The predominant contributors to the aromatic ring groups of the 16 PAHs were four- and five-ring groups, such as fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzor[b]fluoranthene, benzor[k]fluoranthene and benzo[a]pyrene, while two- and three-ring aromatics, like naphthalene, acenapthylene, acenaphthene, fluorene, phenanthrene and anthracene, only exhibited a low concentration. The molecular indices for phenanthrene/anthracene and fluoranthen/pyrene were used to Identify the origin of the PAH contamination in the sediments. The results indicated that the PAH contamination in Ulsan Bay was mostly Pyrolytic in origin with a Petrogenic input adjacent to Ulsan and Jangsuengpo harbor.