• Preventive Nutrition and Food Science
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• v.22 no.3
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• pp.157-165
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• 2017

Fruits of Sonneratia apetala (Buch.-Ham.), (English: mangrove apple, Bengali: keora) both seeds and pericarps, are largely consumed as food besides their enormous medicinal application. The fruit seeds have high content of nutrients and bioactive components. The seeds powder of S. apetala was successively fractionated using n-hexane, diethyl ether, chloroform, ethyl acetate, and methanol. The fractions were used to evaluate antibacterial, anti-diarrhoeal, analgesic, and cytotoxic activities. Methanol fraction of seeds (MeS) stronly inhibited Escherichia coli strains, Salmonella Paratyphi A, Salmonella Typhi, Shigella dysenteriae, and Staphylococcus aureus except Vibrio cholerae at $500{\mu}g/disc$. All the fractions strongly inhibited castor oil induced diarrhoeal episodes and onset time in mice at 500 mg extract/kg body weight (P<0.001). At the same concentration, MeS had the strongest inhibitory activity on diarrhoeal episodes, whereas the n-hexane fraction (HS) significantly (P<0.05) prolonged diarrhoeal onset time as compared to positive control. Similarly, HS (P<0.005) inhibited acetic acid induced writhing in mice at 500 mg extract/kg, more than any other fraction. HS and diethyl ether fractions of seed strongly increased reaction time of mice in hot plate test at 500 mg extract/kg. All the fractions showed strong cytotoxic effects in brine shrimp lethality tests. Gas chromatography-mass spectrometry analysis of HS led to the identification of 23 compounds. Linoleic acid (29.9%), palmitic acid (23.2%), ascorbyl palmitate (21.2%), and stearic acid (10.5%) were the major compounds in HS. These results suggest that seeds of S. apetala could be of great use as nutraceuticals.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.389-394
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• 2001

In order to isolate antimicrobial substances from Schizandra chinensis, the dried fruits were extracted with the methanol and the extract showed a strong antimicrobial activity. Also, the methanol exract was further fractionated with hexane, dichloromethane, ethylacetate and buthanol. The ethyl acetate-soluble fraction showed the strongest antimicrobial activity. These fraction were further separated by using various chromatographic methods including thin layer chromatography, silicagel open column chromatography and prep. HPLC. A major component S-EA-5-T1 and S-EA-5-T3 from the ethyl acetate fraction, which showed a strong antimicrobial activity was identified by Mass and NMR spectrometry. Two compounds were isolated and identified as trimethylcitrate and the essential oil of Schizandra chinensis and was estimated as gomisin C, respectively. The growth of S. typhimurium was also inhibited about 1.65 to 2.86 log cycle in minced pork by the addition 1% of Schizandra chinensis extract for 12 days at $4^{\circ}C$. These results suggested that these compounds have a strong potential as a natual food preservatives.

• New & Renewable Energy
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• v.18 no.4
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• pp.12-21
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• 2022

The pyrolysis characteristics of high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP) were analyzed numerically using a 1D plug flow reactor (PFR) model. A lumped kinetic model was selected to simplify the pyrolysis products as wax, oil, and gas. The simulation was performed in the 400-600℃ range, and the plastic pyrolysis and product generation characteristics with respect to time were compared at various temperatures. It was found that plastic pyrolysis accelerates rapidly as the temperature rises. The amounts of the pyrolysis products wax and oil increase and then decrease with time, whereas the amount of gas produced increases continuously. In LDPE pyrolysis, the pyrolysis time was longer than that observed for other plastics at a specified temperature, and the amount of wax generated was the greatest. The maximum mass fraction of oil was obtained in the order of HDPE, PP, and LDPE at a specified temperature, and it decreased with temperature. Although the 1D model adopted in this study has a limitation in that it does not include material transport and heat transfer phenomena, the qualitative results presented herein could provide base data regarding various types of plastic pyrolysis to predict the product characteristics. These results can in turn be used when designing pyrolysis reactors.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.975-984
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• 2018

Fast pyrolysis bio-oil has unfavorable properties that restrict its use in many applications. Among the main issues are high acidity, instability, and water and oxygen content, which give rise to corrosiveness, polymerization during storage, and a low heating value. Esterification and azeotropic water removal can improve all of these properties. A 500 g of Quercus mongollica which grounded 0.8~1.4 mm was processed into bio-oil via fast pyrolysis for 2 seconds at $550^{\circ}C$. The esterification consists of treating pyrolysis oil with a high boiling alcohol like n-butanol at $70^{\circ}C$ under reduced pressure (100 hPa). All products are analyzed for water mass fraction, viscosity, higher heating value, pH, FT-IR and GC/MS. The water mass fraction can be reduced by 91.4 % (from 31.5 % to below 2.7 %), the viscosity by 65.8 % (from 36.5 to 12.5 cP) and the higher heating value can be increased by 96.8 % (from 3,918 to 7,712 kcal/kg), the pH by 1.3 (from 2.7 to 4.0). FT-IR and GC/MS analysis indicated that labile acids, aldehydes, ketones and lower alcohols were transformed to stable target products. Using this approach, the water content of the pyrolysis oil is reduced significantly. These improvements should allow the utilization of upgraded pyrolysis liquids in standard boilers and as fuel in CHP (Combined heat and power) plants.

• Journal of Microbiology
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• v.45 no.5
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• pp.460-465
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• 2007

This study was carried out in order to investigate the potential of using plant oils derived from Leptospermum petersonii Bailey and Syzygium aromaticum L. Merr. Et Perry as natural antifungal agents. The antifungal effects of essential oils at concentrations of 0.05, 0.1, 0.15, and 0.2 mg/ml on the dermatophytes Microsporum canis (KCTC 6591), Trichophyton mentagrophytes (KCTC 6077), Trichophyton rubrum (KCCM 60443), Epidermophyton floccosum (KCCM 11667), and Microsporum gypseum were evaluated using the agar diffusion method. The major constituents of the active fraction against the dermatophytes were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography analysis. The antifungal activities of S. aromaticum oil (clove oil) against the dermatophytes tested were highest at a concentration of 0.2mg/ml, with an effectiveness of more than 60%. Hyphal growth was completely inhibited in T. mentagrophytes, T. rubrum, and M. gypseum by treatment with clove oil at a concentration of 0.2 mg/ml. Eugenol was the most effective antifungal constituent of clove oil against the dermatophytes T. mentagrophytes and M. canis. Morphological changes in the hyphae of T. mentagrophytes, such as damage to the cell wall and cell membrane and the expansion of the endoplasmic reticulum, after treatment with 0.11 mg/ml eugenol were observed by transmission electron microscopy (TEM). At a concentration of 0.2 mg/ml, L. petersonii oil (LPO) was more than 90% effective against all of the dermatophytes tested, with the exception of T. rubrum. Geranial was determined to be the most active antifungal constituent of L. petersonii oil. Taken together, the results of this study demonstrate that clove and tea tree oils exhibited significant antifungal activities against the dermatophytes tested in this study.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.346-354
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• 1987

The voflatile fraction from Korean mandarin (Citrus reticula) and valencia orange essence oil were analyzed by capillary gas chromatography and the separated components were identified from their retention time and mass pectrum. The essence oil were extracted with methylene chloride after steam distillation. The major volatile constituents of mandarin and sweet orange was limonene which accounted for 68% of total volatiles in mandarin and 87% in sweet orange. The 31 components identified from mandarin include 11 hydrocarbones, 1 ester, 10 alcohols, 4 aldehydes, 5 miscellaneous. The following 37 components were identified in sweet orange; 12 hydrocarbones, 1 ester, 11 alcohols, 8 aldehydes, 5 misecellaneous. Mandarin contained more octanal, ${\alpha}-terpinene$, terpineol, styrene, dcitronellol, citronellal, citral and farnesol while orange included more sweet orange, myrcene, ${\beta}-pinene$, linallol, decanol, ${\beta}-copaene$, elemene, ${\beta}-cadinene$, valencene.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.4
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• pp.207-215
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• 2015

Since the oil shock of 1970's there was a strong upward tendency for the use of the high viscosity and poorer quality fuels. Therefore the misfiring engine occurs due to the decrease of quantity injected for lean burn and emission control in CI diesel engine. In this study, it is designed and used the test bed which is installed with turbocharger and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and emission as operating parameters.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.269-275
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• 2013

Antifungal and insecticidal activity of Korean traditional medicinal plants was carried out to develop natural material for the development of organic cultural heritage conservation. As a result, Phellodendron amurense fruit was finally selected as a candidate of antifungal and insecticidal natural material. An novel active compound was purified from the ethylacetate fraction of Phellodendron amurense fruits using silica gel and Sephadex LH-20 column chromatography and PTLC. The compound was obtained as yellow oil form; UV ${\lambda}_{max}$(MeOH): 260 nm. The chemical structure of novel compound was determined as (4'-ethyl-2'-methylfuranyl)-6-methoxy-7-methylnona-2E,4E,6Z,8E-tetraenoic acid on the basis of various NMR experiments including $^1H$- and $^{13}C$-NMR, HMQC, HMBC and ESI-mass spectrum.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.3
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• pp.317-330
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• 2004

The Purpose of this study was to develop the P $M_{2.5}$ source Profiles, which are mass abundances (fraction of total mass) of a chemical species in P $M_{2.5}$ source emissions. The source categories studied were soil, road dust, gasoline and diesel vehicles, industrial source, municipal incinerator, coal-fired power plant, biomass burning, and marine. The chemicals analyzed were ions. elements. and carbons. From this study, soil source had the crustal components such as Si, hi, and Fe. In the case of road dust. Si, OC, Ca, Fe had large abundances. The abundant species were S $O_4$$^{2-}$, C $l^{[-10]}$ , N $H_4$$^{+}$, and EC in the gasoline vehicle and EC, OC, C $l^{[-10]}$ , and S $O_4$$^{2-}$ in the diesel vehicle. The main components were S $O_4$$^{2-}$, S N $H_4$$^{+}$, and EC in the industrial source using bunker C oil as fuel, C $l^{[-10]}$ , N $H_4$$^{+}$, Fe, and OC in the municipal incinerator source, and Si, Al, S $O_4$$^{2-}$, and OC in the coal -fired power plant source. In the case of biomass burning, OC, EC, and C $l^{[-10]}$ were mainly emitted. The main components in marine were C $l^{[-10]}$ , N $a^{+}$, and S $O_4$$^{2-}$.EX> 2-/.

• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.54-72
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• 2018

This study reviewed standard operation procedures for fractionation and analytical methods of total petroleum hydrocarbons (TPH) in north america and european countries to aid proper establishment of risk assessment protocols associated with TPH exposure in Korea. In current, the TPH fraction methods established by Massachusetts Department of Environmental Protection (MassDEP) and Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) are most frequently employed worldwide. Both methods were developed on the basis of direct exposure of TPH from soil, although the method by TPHCWG also took into account the mobility of TPH. Volatile and extractable fractions of petroleum hydrocarbons were analyzed either separately or together. TPH fractionation methods were evaluated based on conservative toxicity values considering the uncertainty of risk assessment in light of current standard protocol for analyzing soil contaminants in Korea, and it was concluded that the method developed by MassDEP is more appropriate.