• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1067-1072
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• 2009

In vapor compression systems which use refrigerant as a working fluid, the oil is commonly used for compressor lubrication. Since the presence of lubrication oil can change the characteristics properties of refrigerant, the oil affects the heat transfer performance of heat exchanger to a large extent. In this paper, we focus on the effect of PVE oil experimentally on heat transfer performance of the fin-tube heat exchangers which use R410A as a refrigerant. To evaluate the heat transfer performance, the refrigerant to air type test facility chamber has been used. Fin-tube heat exchanger with grooved has been tested while according to the oil mass fraction variation from nearly zero to 1.7 wt%. It was found that the low level of oil mass fraction has an obvious effect on heat transfer performance, while the high level seems no significant influence. The influence of the oil mass fraction to heat transfer performance, however, is different between evaporation and condensation.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.375-382
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• 2002

The total hydrocarbon distribution of oil products obtained from the pyrolysis of four kinds of mixtures of polyethylene-polystyrene waste has been studied by multidimensional chromatography(high performance liquid chromatography followed by capillary gas chromatography)/mass spectrometry. Saturated, unsaturated and aromatic hydrocarbons in oil products were selectively pre-separated according to structural groups by HPLC and the weight fraction of each group was estimated by analysis of each component using GC-FID response factors. The hydrocarbon distribution of aliphatic fraction consists of $C_{5}$ to $C_{25}$ saturated and unsaturated hydrocarbons. And that of aromatics fraction consists of benzene, toluene, xylene, styrene, propenyl benzene, naphthalene, and some of derivatives. Pyrolysis temperature did not affect the ratio of total weight fraction of aliphatic over aromatic hydrocarbon distribution in case of PS only and PE-PS mixtures (1:1 and 1:4 wt. ratio) as a feed while affected the ratio of total wt. fraction in case of PE only. The optimal temperature for the maximum oil production was $600^{\circ}C$ for pyrolysis of PS and 1:1 and 1:4 mixtures of PE and PS. The optimal condition for aromatic recovery was $600^{\circ}C$ with 1:1 mixture of PE and PS. In this condition, aromatic was produced up to 90% of total oil product. The maximum yield of toluene, xylene, styrene, and propenyl benzene were 8.6, 8.9, 51.0 and 7.4% of feed for pyrolysis PS at $700^{\circ}C$, respectively. However, only 1.3% naphthalene was recovered at $700^{\circ}C$ with 1:1 PE:PS(by wt.).

• Natural Product Sciences
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• v.10 no.6
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• pp.325-329
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• 2004

The composition of essential oil from O. javanica was analyzed by gas chromatography-mass spectrometry. Using the broth dilution method and disk diffusion test, anti-microbial activities of the oil fraction and its main components were evaluated against various antibiotic-susceptible and resistant strains of pathogenic microorganisms. As a result of GC-MS analysis, 57 compounds, including ${\alpha}-terpinolene$ (28.1%), dl-limonene (16.0%), ${\gamma}-terpinene$ (10.3%), ${\beta}-pinene$ (9.7%) and ${\alpha}-pinene$ (6.0%) were identified in the essential oil fraction. The essential oil fraction of O. javanica and its main components exhibited significant inhibitory activities, particularly against Candida albicans (antibiotic-susceptible strains) and Streptococcus pneumoniae (antibiotic- susceptible and resistant strains). The main components of the O. javanica oil fraction displayed different patterns of activity against the three tested Candida species as exemplified by the differential minimum inhibiting concentration (MIC) values. The disk diffusion test showed that the activities were dose dependent.

• Natural Product Sciences
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• v.18 no.4
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• pp.244-249
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• 2012

Angelica acutiloba is one of the most intensively cultivated medicinal plants in Korea. The roots of this plant have been used as an important herbal drug, especially for the treatment of various female disorders, as the traditional therapy in Korea and other Asian countries. Consumption of its fresh leaves as a healthy vegetable has recently increased. In this study, essential oil fractions were extracted from the roots and leaves of this plant by steam distillation. Compositions of the two oils were compared by gas chromatography-mass spectrometry (GC-MS). The antibacterial activities of the essential oil were determined against three strains of Escherichia coli. DPPH radical scavenging and reducing power tests were performed to evaluateits antioxidant activities. The cytotoxic activities of the essential oil against a human breast and a uterine cancer cell line were estimated by MTT tests. Additionally, the morphological changes after treatment of the oil fraction were observed under a microscope. The essential oil fraction and its main components, Z-ligustilide and butylidene phthalide, inhibited the growth of three E. coli strains examined, with minimum inhibiting concentrations (MICs) ranging from 1.0 mg/ml to 8.0 mg/ml. Additionally, the essential oil fraction of A. acutiloba exhibited significant DPPH free radical scavenging activity and reducing power. Significant cytotoxic activities of the A. acutiloba essential oil were observed for human uterine (Hela) and breast (MCF-7) cancer cell lines.

• Journal of the Korean Society of Tobacco Science
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• v.4 no.2
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• pp.67-73
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• 1982

Essential oil components from tobacco powder were investigated as flavouring agent. The essential oil was isolated from tobacco powder by a simple distillation /extraction method The extracted essential oil was fractionated into basic, acidic and neutral groups. And the neutral group of essential oil was separated by column chromatography into 10 fractions. Above groups and fractions were tested for tobacco aroma and smoke aroma. The neutral group except most nonpolar fraction displays good flavouring properties which make them highly suitable for improving the flavour and aroma of tobacco and tobacco smoke. The most nonpolar fraction from neutral group was carefully investigated using preparative column, thin layer and gas chromatography ailed by GC/MS coupling. The major subfraction was identified as hydrocarbons on the basis of the IR spectrum. The 58 hydrocarbon components were identified by their mass spectra and was chromatographic retention times.

• YAKHAK HOEJI
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• v.54 no.2
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• pp.122-125
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• 2010

The essential oil fraction was extracted from the aerial parts of the plant by steam distillation method and its composition was analyzed by GC-MS (gas chromatography-mass spectrometry) which led to the identification of 43 compounds. Dehydroelsholtzia ketone (56.81%) and elsholtzia ketone (30.05%) were identified as the predominant components of this oil. The antibacterial activities of the essential oil fraction were assessed by micro-dilution tests against antibioticsusceptible and -resistant strains of Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enteritidis, and S. typhimurium. The oil inhibited most of the tested strains significantly resulting MICs (minimum inhibiting concentrations) between 2 mg/ml and >16 mg/ml. In most cases of this study Streptococcus pneumoniae and Staphylococcus aureus showed higher sensitivity to this oil than Salmonella strains.

• Journal of Mechanical Science and Technology
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• v.14 no.5
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• pp.537-546
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• 2000

The heat transfer characteristics of refrigerant-oil mixture for horizontal in-tube evaporator have been investigated experimentally. A smooth copper tube and a micro-fin tube with nominal 9.5 mm outer diameter and 1500 mm length were tested. For the pure refrigerant flow, the dependence of the axial heat transfer coefficient on quality was weak in the smooth tube, but in the micro-fin tube, the coefficients were 3 to 10 times greater as quality increases. Oil addition to pure refrigerant in the smooth tube altered the flow pattern dramatically at low mass fluxes, with a resultant enhancement of the wetting area by vigorous foaming. The heat transfer coefficients of the mixture for low and medium qualities were increased at low mass fluxes. In the micro-fin tube, however, the addition of oil deteriorates the local heat transfer performance for most of the quality range, except for low quality. The micro-fin tube consequently loses its advantage of high heat transfer performance for an oil fraction of 5%. Results are presented as plots of local heat transfer coefficient versus quality.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.55-63
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• 1992

The essential oil of Korean ginger(Zingiber officinale Roscoe) was isolated by liquid carbon dioxide extraction method and fractionated into one hydrocarbon fraction and two oxygenated hydrocarbon fractions by using silica gel column chromatography. The compositions of the resulting oils were investigated by GC and GC-MS spectrometry. Out of 102 identified compounds, 44 were identified by comparing GC retention time and mass spectral data with authentic samples and 58 were tentatively identified according to mass spectral data only. The major compounds of hydrocarhon fraction were $zingiberene,\;{\beta}-sesquiphellandrene,\;{\gamma}-bisabolene,\;{\gamma}-cardinene,\;ar-curcumene$, and those of oxygenated hydrocarbon fractions wee geranal, sesquisabinene hydrate, borneol and zingiberenol. The major compounds of ginger oil were zingiberene, $citronellol+{\beta}-sesquiphellandrene,\;geranial,\;{\gamma}-bisabolene\;and\;ar-curcumene+geranyl\;acetate$, and ginger oil contained higher amounts of sesquiterpene hydrocarbons. The yield of extract was 6.96%.

• Food Science and Preservation
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• v.30 no.6
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• pp.944-959
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• 2023

This study investigated the essential oil composition of fresh Panax ginseng root and identified novel compounds from ginseng oil. The oil was divided into five fractions (neutral, basic, phenolic, acidic, and aldehydic). In total, 149 constituents, including 29, 19, and 38 compounds in the basic, phenolic, and aldehydic fractions, respectively, were identified by gas chromatography (GC) and GC-mass spectrometry (MS). The primary constituents of the total ginseng volatile oil were α-humulene (13.91% as a peak area), bicyclogermacrene (13.59%), β-caryophyllene (8.24%), α-neoclovene (7.78%), and α- and β-panasinsenes (5.14% and 7.53%). The primary constituents of the basic fraction were 2-isopropyl-3-methoxypyrazine (35.51%), 3-sec-butyl-2-methoxy-5-methylpyrazine (31.54%), 2-isobutyl-3-methoxypyrazine (8.64%), and 2-methoxy-3-methylpyrazine (8.40%), whereas in the phenolic fraction, these were benzoic (25.40%), octanoic (11.57%), nonanoic (9.16%), propionic (6.35%), and decanoic acids (6.16%). The primary constituents of the aldehydic fraction were 4-(2-furyl)-3-buten-2-one (23.41%), benzaldehyde (10.18%), cis-2-heptanal (9.42%), 3-(α-furyl)-propenal (8.51%), and 2-phenyl-2-butenal (7.28%). Among these, the phenylalkenal compounds, including 2-phenyl-2-butenal, 2-methyl-3-phenyl-2-propenal, 5-methyl-2-phenyl-2-pentenal, 5-methyl-2-phenyl-2-hexenals, 2-phenyl-2-octenal, and 2-phenyl-2-nonenal, were newly identified in this study as ginseng volatile constituents. Furthermore, 2-phenyl-2-nonenal was identified as a plant-based volatile constituent for the first time in this study.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.141-149
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• 1991

The essential oils of the two cultivars of Korean ginger were isolated by simultaneous steam distillation and extraction method. Then the essential oils were fractionated into one hydrocarbon fraction and two oxygented hydrocarbon fractions by using silica gel column chromatography. The composition of the resulting oils were investigated by GC-MS spectrometry. The volatile oil contents of the two fresh cultivars were 0.32%(wb) and consisted of 68.1% hydrocarbon and 31.9% oxygenated hydrocarbons. Out of 101 characterized compounds, 54 were identified by comparing GC retentions and mass spectral data with authentic samples and 47 were tentatively identified according to mass spectral data only. The major compounds of hydrocarbon fraction were camphene, ${\beta}-phellandrene$, zingiberene, ${\gamma}-bisabolene,\;{\bate}-sesquiphellandrene$, and of oxygenated hydrocarbon fractions were 1,8-cineol, neral, geranial, geranyl acetate, citronellol, geraniol and ${\alpha}-terpeneol+borneol$. Comparing the yield and composition of Korean ginger oil with those from other origins reported, Korean ginger oils showed good yields of oil, whilst those contained higher amounts of sesquiterpene hydrocarbons.