• Journal of the Korean Society of Safety
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• v.25 no.2
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• pp.35-40
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• 2010

Explosion limit and flash point are the major combustion properties used to determine the fire and explosion hazards of the flammable substances. In this study, in order to predict upper explosion limits(UEL), the upper flash point of n-alcohols were measured under the VLE(vapor-liquid equilibrium) state by using Setaflash closed cup tester(ASTM D3278). The UELs calculated by Antoine equation using the experimental upper flash point are usually lower than the several reported UELs. From the given results, using the proposed experimental and predicted method, it is possible to research the upper explosion limits of the other flammable substances.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1654-1659
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• 2008

The aim of this study was to compare the fermentation characteristics of tissue cultured mountain ginseng, extruded tissue cultured mountain ginseng, and root hair of red ginseng. Also, pH, acidity, brix, reducing sugar, total sugar, and alcohol were analyzed. The extrusion conditions were barrel temperature of 110 and $140^{\circ}C$ and moisture content of 25 and 35%. Fermentation temperature was $27^{\circ}C$ for 15 days and the cultivation was fixed with Saccharomyces cerevisiae, Aspergillus usamii, and Rhizopus japonicus. The results showed that pH, brix, reducing sugar content, and total sugar content of fermented broths were decreased after 5 days and then maintained steadily for the following 10 days. Acidity of final fermented broths were 1.12% (root hair of red ginseng), 1.19% (tissue cultured mountain ginseng), and $0.97{\sim}1.02%$ (extruded tissue cultured mountain ginseng), respectively. Alcohol content of final fermented broths were 3.82% (root hair of red ginseng), 0.91% (tissue cultured mountain ginseng), and $1.86{\sim}2.18%$ (extruded tissue cultured mountain ginseng). The fermentation efficiency of extruded tissue cultured mountain ginseng (barrel temperature $140^{\circ}C$, moisture content 25%) were the highest. In conclusion, the fermentation efficiency was increased by extrusion process.

• Food Science and Preservation
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• v.13 no.1
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• pp.108-114
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• 2006

This study was conducted to determine the volatile flavor compositions of the essential oil and the headspace of Capsella bursa-pastoris Medicus. Essential oil and headspace from the plant were extracted by simultaneous steam distillation extraction (SDE), and solid-phase microextraction(SPME) methods, respectively. Seventy-two compounds including 28 hydrocarbons, 4 aldehydes, 6 ketones, 16 alcohols, 4 esters, 8 acids, and 6 miscellaneous ones were identified in the leaf essential oil extracted by SDE method Sixty-eight compounds including 26 hydrocarbons, 2 aldehydes, 6 ketones, 17 alcohols, 4 esters, 6 acids, and 7 miscellaneous ones were identified in the root essential oil. According to the instrumental analyses the essential oil, phytol ($21.12\%$ in leaves, $20.94\%$ in roots) was the most abundant compound Alcohols, esters, and acids were main groups of the essential oil. On the other hand, thirty-eight compounds including 18 hydrocarbons, 3 aldehydes, 3 ketones, 9 alcohols, 2 esters, 3 miscellaneous ones were identified in the leaf headspace by SPME. In root headspace, thirty-three compounds including 16 hydrocarbons, 2 aldehydes, 1 ketone, 9 alcohols, 3 esten;, and 2 miscellaneous ones were identified. Hydrocarbons($44.02\%$ in leaves, $56.98\%$ in roots) were the main components of the headspace of Capsella bursa-pastoris Medicus.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.55-59
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• 2008

The composition of essential oil from the aerial part of Erigeron canadensis L. was analyzed by GC-MS. Thirty-one constituents were identified from the essential oil: eighteen hydrocarbons (91.99% of the total oil), two acetates (2.92%), three alcohols (3.59%), four ethers (0.49%), one aldehyde (0.05%), and three ketone (0.23%). Major constituents of the essential oil were D,L-limonene (68.25% of the total oil) and delta-3-carene (15.9%). The $IC_{50}$ value of the essential oil was 0.027 ${\mu}g$ $mg^{-1}$ in MTT assay using HaCaT keratinocyte cell line.

• Applied Chemistry for Engineering
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• v.25 no.6
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• pp.648-653
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• 2014

Cr(VI)-heterocyclic complex (2,4'-bipyridinium chlorochromate) was synthesized by the reaction between heterocyclic compound(2,4'-bipyridine) and chromium trioxide, and characterized by IR and ICP analysis. The oxidation of benzyl alcohol using 2,4'-bipyridinium chlorochromate in various solvents showed that the reactivity increased with the increase of the dielectric constant (${\varepsilon}$), in the order : N,N-dimet-hylformamide (DMF) > acetone > chloroform > cyclohexene. In the presence of DMF solvent with acidic catalyst such as hydrochloric acid (HCl solution), 2,4'-bipyridinium chlorochromate oxidized benzyl alcohol (H) and its derivatives (p-$CH_3$, m-Br, m-$NO_2$). Electron-donating substituents accelerated the reaction rate, whereas electron acceptor groups retarded the reaction rate. The Hammett reaction constant (${\rho}$) was -0.67 (303 K). The observed experimental data have been rationalize the proton transfer occurred followed the formation of a chromate ester in the rate-determining step.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.219-223
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• 2014

The purpose of this study was to investigate the protective effects of fucoidan on acute alcohol-induced liver injury in rats. Experimental animals were randomly divided into four groups: (1) a control group, (2) a group fed 25% ethanol, (3) a group fed 25% ethanol and 250 mg/kg BW of fucoidan (25% ethanol+FUCO250), and (4) a group fed 25% ethanol and 500 mg/kg BW of fucoidan (25% ethanol+FUCO500). Each group was fed orally two times per day for 15 days. Liver weights in the 25% ethanol group were increased compared to the control group, while liver weights in the 25% ethanol+FUCO500 group were significantly decreased compared to the 25% ethanol group (p<0.05). Plasma concentrations of triglyceride, cholesterol, and LDL-cholesterol were elevated in the 25% ethanol group; however, these levels in the 25% ethanol+FUCO250 group were significantly decreased compared to the 25% ethanol group (p<0.05). The glutamic-pyruvic transaminase activity of the 25% ethanol+FUCO500 group also was significantly lower than the 25% ethanol group (p<0.05). These results indicate that fucoidan might protect against acute alcohol-induced liver injury.

• Polymer(Korea)
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• v.24 no.5
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• pp.610-620
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• 2000

Vinyl acetate (VAc) was polymerized at 30, 40, and 5$0^{\circ}C$ using 2,2'-azobis (2,4-dimethylvaleronitrile) (ADMVN) and tertiary butyl alcohol (TBA) as the initiator and the solvent, respectively. High molecular weight (HMW) atactic poly(vinyl alcohol) (PVA) was prepared by saponifying the poly(vinyl acetate) (PVAc) synthesized. The effect of polymerization conditions were investigated in terms of conversion, degree of branching for acetyl group of PVAc, and molecular weight of both PVAc and PVA. The polymerization rate of VAc in TBA was proportional to the 0.49th power of ADMVN concentration in good accordance with the theoretical value of 0.5. HMW-PVA with high yield could be obtained successfully, probably due to lower polymerization temperature and decreased chain transfer reaction rate which was achieved by adopting ADMVN and TBA. PYAc having average degree of polymerization (P$_{n}$) of 10000~13000 was obtained at the conversion of 35~70%. Saponification of so prepared PVAc yielded PVA having P$_{n}$ of 2400~6100. The syndiotactic diad content increased with decreasing polymerization temperature and increasing VAc concentration due to a steric hindrance effect of TBA during polymerization.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.222-228
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• 2018

Benzene is one of the most widely used basic materials in the petrochemical industry. Generally, benzene exists as a mixture with alcohols rather than as a pure substance. Further, the alcohols-added mixtures usually exhibit an azeotropic composition. In this context, knowledge of the phase equilibrium behavior of the mixture is essential for its separation and purification. In this study, the vapor-liquid equilibrium data were measured in favor of a recirculating VLE apparatus under constant pressure for the 1 - propanol / benzene system. The measured vapor - liquid equilibrium data were also correlated by using the UNIQUAC and WILSON models and the thermodynamic consistency test based on the Gibbs/Duhem equation was followed. The results of the phase equilibrium experiment revealed RMSEs (Root Mean Square Error) and AADs (Average Absolute Deviation) of less than 0.05 for both models, indicating a good agreement between the experimental value and the calculated value. The results of the thermodynamic consistency test also confirmed through the residual term within ${\pm}0.2$.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.634-647
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• 2019

Purpose: Currently, many chemicals are used in industrial and real life, and many substances are used in the form of a single substance, but most of them are used in the form of a mixture, and there is a need for a criterion for judging the danger of these substances. Method: Therefore, this study aims to confirm the risk criteria of the mixture through experimental studies on flammable mixtures in order to secure the effectiveness of the details of the existing Dangerous Goods Safety Management Act angerous Goods Judgment Criteria and to ensure the reliability and reproducibility of the dangerous goods judgment. Result: Experimental results show that alcohol flash point is mixed with water, which is a non-flammable liquid. Similar flash point trends occurred around 60% on an alcohol basis. In addition, in the case of flammable-combustible mixtures, there was little change in flash point if the flash point difference of the two materials was not large, and if the flash point difference of the two materials was low, the flash point tended to increase with the increase of the high flash point material. Conclusion: In the future, the test results may provide reference data on the experimental criteria for the flammable liquids that are cracked at the fire site.

• Clean Technology
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• v.28 no.3
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• pp.232-237
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• 2022

Biorefineries, in which renewable resources are utilized, are an eco-friendly alternative based on biomass feedstocks. Alginic acid, a major component of brown algae, which is a type of marine biomass, is widely used in various industries and can be converted into value-added chemicals such as sugars, sugar alcohols, furans, and organic acids via catalytic hydrothermal decomposition under certain conditions. In this study, ruthenium-supported activated carbon and magnesium oxide were mixed and applied to the depolymerization of alginic acid in a batch reactor. The addition of magnesium oxide as a basic promoter had a strong influence on product distribution. In this heterogeneous catalytic system, the separation and purification processes are also simplified. After the reaction, low molecular weight alcohols and organic acids with 5 or fewer carbons were produced. Specifically, under the optimal reaction conditions of 30 mL of 1 wt% alginic acid aqueous solution, 100 mg of ruthenium-supported activated carbon, 100 mg of magnesium oxide, 210 ℃ of reaction temperature, and 1 h of reaction time, total carbon yields of 29.8% for alcohols and 43.8% for a liquid product were obtained. Hence, it is suggested that this catalytic system results in the enhanced hydrogenolysis of alginic acid to value-added chemicals.