• Natural Product Sciences
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• v.19 no.4
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• pp.297-302
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• 2013

The current study was conducted to evaluate the antibacterial and antioxidant activities of the essential oil fraction from the roots of Angelica tenuissima Nakai and its main components. We extracted the essential oil fraction from the roots of A. tenuissima using steam distillation and isolated its main components. Their antibacterial activities were determined by broth dilution test against food-borne pathogenic bacteria. Antioxidant activities were evaluated by DPPH-scavenging assay and reducing-power test. Also tested was their ability to inhibit the growth of two gastrointestinal cancer cell lines, Caco-2 and MKN-45. The A. tenuissima oil fraction and its main components, ligustilide and butylidene phthalide exhibited marked inhibitory effects against most of the tested antibiotic-susceptible and antibiotic-resistant bacterial strains with minimum inhibiting concentrations (MICs) from $0.21{\pm}0.08$ to $3.60{\pm}0.89mg/ml$. They also showed growth-inhibiting activity against Caco-2 and MKN-45 cells. The oil fraction showed significant antioxidant activities in DPPH radical scavenging assay and reducing-power test. Taken together, A. tenuissima essential oil could be used as a safe additive for preventing food contamination by pathogenic bacteria. Additionally, its antioxidative activity and the ability to inhibit gastrointestinal carcinoma cell lines could increase its value for functional foods and prevention of cancer.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.307-312
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• 2001

Flavor compounds in Neungee (sarcodon aspratus) were extracted by simutaneous distillation and extraction (SDE), supercritical fluid extraction (SFE) and headspace method. Flavor compounds obtained by various extraction methods were analyzed with GC and GC-MS. The funtionality of flavor compounds were determined by aroma extract dilution analysis (AEDA) of GC-ofactometry methods. Fifty one flavor compounds were totally identified in Neungee mushroom. However, the numbers of flavor extracted SDE, SFE and headspace were 33, 26 and 17 respectively. The major flavor compounds obtained by SDE, SFE and headspace were 1-octen-3-ol, 1-octen-3-one, 3-octanone, 2-octen-1-ol, 3-octanol, 1-octanol and benzenealdehyde. As the results of sniffing test, the major flavor compounds were found to be fresh mushroom flavor, wood flavor, refreshing sweet flavor, mold flavor, bitter-mushroom and metalic-flavor.

• Membrane and Water Treatment
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• v.10 no.4
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• pp.287-298
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• 2019

Lotus leaf has a special dual micro and nano surface structure which gives its highly hydrophobic surface characteristics and so-called self cleaning effect. In order to endow PVDF hollow fiber membrane with this special structure and improve the hydrophobicity of membrane surface, PVDF hollow fiber composite membranes was obtained through the immersion coating of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) dilute solution on the outside surface of PVDF support membrane. The prepared PVDF composite membranes were used in the vacuum membrane distillation (VMD) for the desalination. The effects of PVDF-HFP dilute solution concentration in the dope solution and coating time on VMD separation performance was studied. Membranes were characterized by SEM, WCA measurement, porosity, and liquid entry pressure of water. VMD test was carried out using $35g{\cdot}L^{-1}$ NaCl aqueous solution as the feed solution at feed temperature of $30^{\circ}C$ and the permeate pressure of 31.3 kPa. The vapour flux reached a maximum when PVDF-HFP concentration in the dilute solution was 5 wt% and the coating time was kept in the range of 10-60 s. This was attributed to the well configuration of micro-nano rods which was similar with the dual micro-nano structure on the lotus leaf. Compared with the original PVDF membrane, the salt rejection can be well maintained which was greater than 99.99 % meanwhile permeation water conductivity was kept at a low value of $7-9{\mu}S{\cdot}cm^{-1}$ during the continuous testing for 360 h.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.845-855
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• 2021

In this study, Camellia sinensis Leaf cultivated in Boseong was extracted by vacuum distillation and hydrothermal extraction methods, and we performed in vitro experiments such as antioxidant, anti-wrinkle, whitening, and antibacterial activity test and HPLC analysis. Wrinkle improvement (elastase inhibition assay) and whitening effect (mushroom tyrosinase inhibition assay) of Boseong vacuum distilled extract have excellent results and IC50 values of vacuum distillation extract was measured at a lower concentration than that of the hydrothermal extract. The antioxidant activity of the Boseong hydrothermal extract was excellently measured in DPPH radical and ABTS+ radical scavenging activity, SOD-like activity, and total polyphenol content. In the antibacterial experiment, the Boseong hydrothermal extract formed a clear zone for the Staphylococcus aureus and Cutibacterium acnes strain. As a result of HPLC analysis, EGCG and caffeine in the hydrothermal extract were 40.29 mg/g, 9.94 mg/g respectively, and caffeine in the vacuum distilled extract was 3.40 mg/g. Therefore, we examined that Boseong Camellia sinensis vacuum distilled extract has excellent anti-wrinkle and whitening effect, and its hydrothermal extract has good antioxidant and antibacterial efficacy.

• International Journal of Automotive Technology
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• v.5 no.4
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• pp.311-319
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• 2004

There are many methods to test engine emissions depending on the regulations used such as FTP-75(CYS-75) mode, 10-15 mode and ECE-15 mode. Most of these modes consist of transient conditions such as cranking, rapid acceleration or deceleration modes. In this experimental research, the transient characteristics including cranking and accelerating mode in SI engines were studied to compare pure gasoline with methanol-reformulated fuels for performance and exhaust emissions. The results show that methanol-reformulated fuels have a better emissions reduction rate than that of pure gasoline especially for HC, CO and NOx emissions during cranking mode. The acceleration performances conform to the results of the distillation curve and the CO concentration for RM50 varies slightly in acceleration mode.

• The Korean Journal of Food And Nutrition
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• v.12 no.2
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• pp.119-123
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• 1999

Test of the optimum condition of solid phase micro extraction(SPME) was performed by use of 5 vol-atile components in dilute aqueous solution. Volatile components of Sancho(Zanthoxylum schinifolium) were isolated by SPME method and were analyzed by GC/MSD and compared with volatile compone-nts isolated by simultaneous distillation extraction (SDE) method. Total 31 components were identified by comparing gas chromatography retention time and mass spectral data. The major compounds were limonene geranyl acetate $\beta$-phellandrene phellandral mycene linalool rose oxide caproic acid and caprylic acid SPME sampling procedure was found to be a good method for qualitative analysis of the volatile components.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.1
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• pp.52-58
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• 2004

To develop a low emission engine, it is necessary to obtain some better quality of automotive fuels. Sulfur in fuel is transformed to sulfate-laden PM as DOC is applied. Therefore, it necessary to provide low sulfur fuels before DOC is applied. According to the specification of test fuels, flash point, distillation 90％, cetane index are improved but viscosity is decreased in the process of desulfurization. Excessively reduced sulfur may cause to decrease lubricity of fuel and engine performance in fuel injection system. Therefore, this research was emphasized how the application of Bio-diesel affects on the emission characteristics and engine performance under the circumstance of ULSD and DOC.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.291-296
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• 2012

The dried roots of Angelica decursiva and Peucedanum praeruptorum are registered as the official sources for the drug 'Junho' in Korean Herbal Pharmacopoeia. In this study the essential oils were extracted from the roots of the two plants by steam distillation. Their compositions and the biological activities were compared. As the results of GC and GC-MS analysis, forty one and thirty five compounds were identified in the essential oils of Angelica decursiva and Peucedanum praeruptorum, respectively. Both of the two essential oils contained ${\alpha}$-pinene as the most abundant component. They showed similar significant antioxidant activities in DPPH scavenging assay, and reducing power test. Their dose dependent inhibitions of the nitrosamine formation were identified in experiment using BHA as control. In MTT test of three cancer cell lines, HeLa, MCF-7 and SK-Hep-1, the essential oil from A. decursiva showed stronger activities than that of P. praeruptorum and their common main component, ${\alpha}$-pinene.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.364-370
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• 2003

Essential oil of Thuja occidental leaves was extracted by steam distillation method, and chemical composition of essential oil was analyzed by GC-MS. The essential oil was tested to antimicrorbiaI activity against 28 test microorganisms and antioxident assay through DPPH free radical scaveging test and insecticidal activity by mosquito insecticide assay. The major constituents in the essential oil of T. occidental were monoterpene as d-isothujone, ${\alpha}-thujone$, camphor, L-fenchone, and hornyl acetate. The essential oil have broad antimicrobiaI activity, which showed strong antimicrobiaI activity for Streptococcus pyogenes as bacteria, Alternaria alternata, Aspergillus niger, Aspergillus oryzae, Saccharomyces cerevisiae, and Streptococcus mutans as fungi. The essential oil also showed DPPH free radical scavenging ability at concentration of $36\;{\mu}{\ell}/m{\ell}$. In spraying and fumigation tests, the essential oil had strong insecticidal activity against mosquito.

• Journal of Power System Engineering
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• v.22 no.6
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• pp.67-73
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• 2018

Gasoline that meets the quality standards is distributed in Korea. However, consumers who use toluene or solvent mixed with gasoline have appeared due to rising crude oil prices and for the purpose of tax evasion. Gasoline quality standard is enacted by the domestic and international research reference. A wrong fuel can influence automobile performance or environmental issue. Thus, empirical data from this issue is necessary. Therefore, this research observed catalyst influence by gasoline property change and inspect influence of environment. In this study, fuel property evaluation, lean-burn evaluation, and real vehicle exhaust emission test were performed. In the result of fuel property, the fuel "A" was measured to be up to 27% less octane than the normal gasoline and the distillation property was measured 24% higher than normal gasoline. In the test result of single cylinder engine lean-burn test, the fuels "A" and "B" show torque value 20% less than the normal gasoline. As a result of vehicle test using the catalyst, the fuel "A" was increased more than the normal gasoline with 83% THC, 1,806% CO and 128% NOx, and the fuel "B" was increased more than normal gasoline with 1.6% THC, 391% CO and 142% NOx.