• Journal of Hydrogen and New Energy
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• v.30 no.2
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• pp.111-118
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• 2019

Greenhouse gas emissions have a profound effect on global warming. Various environmental regulations have been introduced to reduce the emissions. The largest amount of greenhouse gases, including carbon dioxide, is produced in the steel industry. To decrease carbon dioxide emission, hydrogen-based iron oxide reduction, which can replace carbon-based reduction has received a great attention. Iron production generates various by-product gases, such as cokes oven gas (COG), blast furnace gas (BFG), and Linz-Donawitz gas (LDG). In particular, COG, due to its high concentrations of hydrogen and methane, can be reformed to become a major source of hydrogen for reducing iron oxide. Nevertheless, continuous COG cannot be supplied under actual operation condition of steel industry. To solve this problem, this study proposed to use two alternative COG-based fuel mixtures; one with natural gas and the other with biogas. Reforming study on two types of mixed gas were carried out to evaluate catalyst performance under a variety of operating conditions. In addition, methane conversion and product composition were investigated both theoretically and experimentally.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.1
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• pp.177-188
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• 1987

A compute program based on the minimization of total Gibbs' free energy and enthalpy balance was developed to calculate the chemical equilibrium composition and adiabatic flame temperature, especially stressed on NO and CO concentration of Heavy oil. Twenty four components of combustion gases which would be produced from the combustion of Heavy oil were chosen and utilized for the products composition analysis of competing combustion reaction. As the results, following conclusions were turned out; (1) Maximum adiabatic flame temperature was found around to be 2900K, when the stoichiometric air ratio was 0.8. (2) Maximum NO quantity in adiabatic process was occurred when supplied air quantity was around 120% of theoretical air requirement. (3) NO and CO quantities were increased with combustion gas temperature at constant stoichiometric air ratio. (4) At constant temperature of combustion gas, NO quantity was increased and Co quantity was decreased with supplied air quantity.

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.363-370
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• 2017

This study investigated the chemical composition of headspace gas from white-flowered lotus (Nelumbo nucifera Gaertner). Volatile flavor compositions of headspace from white-flowered lotus (floral leaf, stamen, flower stalk, stem) were investigated through the solid-phase microextraction method using polydimethylsiloxane-divinylbenzene fiber. The headspace was directly transferred to a gas chromatography-mass spectrometry. Sixty-three volatile flavor constituents were detected in the headspace of lotus floral leaves, and undecanoic acid (7.81%) was the most abundant component. Fifty-three volatile flavor constituents were detected in the headspace of lotus stamina, and isobutylidene phthalide (7.94%) was the most abundant component. Forty-four volatile flavor constituents were detected in the headspace of lotus flower stalks, and 3-butyl dihydrophthalide (11.23%) was the most abundant component. Fifty-nine volatile flavor constituents were detected in the headspace of lotus stems, and ligustilide (16.15%) was the most abundant component. The content of phthalides was higher in the headspace of flower stalks and stems, while alcohols and acids were the predominant compounds in lotus floral leaves.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.1
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• pp.9-15
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• 2004

$CO_2$ is a well-known green house gas as well as the major source of global warming. Many researchers have studied to reduce $CO_2$ emission in combustion processes. Among the method for reducing $CO_2$ emission, oxygen-enriched combustion has been proposed. Because its adiabatic flame temperature is relatively too high, existing facilities must be changed or the flame temperature in the combustion zone should be reduced. The combustion characteristics, composition in the flame zone, temperature profile and emission gases were investigated experimentally for the various oxygen-enriched ratios(OER) by the addition of $CO_2$, under constant $O_2$ flow rate. Results showed that the reaction zone was quenched and broadened as the addition of $CO_2$ was increased. The emission of NOx in flue gas was decreased as decreasing temperature in reaction zone. It was also shown that the reaction was delayed by the cooling effect. As the addition of $CO_2$ was increased, the composition of CO in the flame zone was increased due to the increase of reaction rate by increasing mixing effect of oxidant/fuel at OER=0％, but the composition of CO was decreased by quenching effect at OER=50％ and 100％.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1389-1394
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• 2003

$CO_2$ is a well-known green house gas, which is the major source of global warming. Many researchers have studied to reduce $CO_2$ emission in combustion processes. Among the method for reducing $CO_2$ emission, oxygen-enriched combustion has been proposed. But the adiabatic flame temperature is too high. So existing facilities must be changed, or the adiabatic flame temperature in the combustion zone should be reduced. The combustion characteristics, composition in the flame zone, temperature profile and emission gases were studied experimentally for the various oxygen-enriched mtios(OER) by addition of $CO_2$ under coustant $O_2$ flowrate. Results showed that the reaction zone was quenched, broadened, as addition of $CO_2$ was increased. Temperature has a large effect on the NOx emission. The emission of NOx in flue gas decreased due to the decreased temperature of reaction zone. It was also shown that the reaction was delayed by the cooling effect. As the addition of $CO_2$ was increased, the composition of CO in the flame zone increased due to the increase of reaction rate by increasing mixing effect of oxidant/fuel at OER=0, but the composition of CO decreased by quenching effect at OER=50 and 100%.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.292-298
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• 2008

The volatile composition of Kiyomi peel oil cultivated in Korea was studied by using gas chromatography and gas chromatography-mass spectrometry. The peel oil from the Kiyomi fruit was prepared by using a cold-pressing extraction method. Among the 65 components quantified in Kiyomi oil, 25 terpene hydrocarbons and 40 oxygenated compounds were identified, with peak weight percentages measuring 94.5% and 4.9%, respectively. Limonene was the predominant compound (87.5%), followed by myrcene (2.4%), sabinene (0.9%), $\alpha$-pinene (0.8%), $\beta$-sinensal (0.8%), (Z)-$\beta$-farnesene (0.7%), neryl acetate (0.6%), valencene (0.5%), $\alpha$-farnesene (0.5%), and $\alpha$-sinensal (0.5%). A unique characteristic of the volatile profile of the Kiyomi oil was the proportion of aldehydes (2.7%), which resulted from the relative abundance of $\alpha$- and $\beta$-sinensal. Another unique characteristic of the Korean Kiyomi oil was its relative abundance of $\beta$-sinensal, (Z)-$\beta$-farnesene, neryl acetate, valencene, $\alpha$-sinensal and nootkatone. Valencene and $\alpha$- and $\beta$-sinensal were regarded as the influential components of Korean Kiyomi peel oil.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.975-988
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• 2023

The fatty acid composition and small molecular metabolites in breast and leg meat of Yanjin blackbone chickens (YBC) and Piao chickens (PC) were detected by gas chromatography-mass spectrometry and liquid chromatography-quadrupole static field orbital trap mass spectrometry. Thirty-two fatty acids were detected, and the total fatty acid content of PC was significantly higher than that of YBC (p<0.05). Oleic acid, linoleic acid, palmitic acid, stearic acid, and arachidonic acid were the main fatty acids in the two chicken varieties, and the composition of fatty acids in the two varieties were mainly unsaturated fatty acids, being more than 61.10% of the total fatty acids. Meanwhile, 12 and 16 compounds were screened out from chicken legs and chicken breasts of YBC and PC, respectively, which had important contributions to the differences between groups.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.1
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• pp.1-10
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• 1981

Volatile compounds in the headspace vapors of five aromatic tobacco varieties have been examined us ins the polymer adsorption method and high- resolution glass capillary gas chromatography. The gas chromatographic profiles thus obtained were compared, and the aroma composition was found to be characteristic of each tobacco sample with significant differences in the concentrations of major components.

• Journal of Mechanical Science and Technology
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• v.14 no.3
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• pp.298-305
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• 2000

The functionally graded material (FGM) is the new concept for a heat resisting material. FGM consists of ceramics on one side and metal on the other. A composition and microstructure of an intermediate layer change continuously from ceramics to metal at the micron level. This study is carried out to analyze the thermal shock characteristics of functionally graded PSZ/ metal composites. Heat-resistant property was evaluated by gas burner heating test using $C_2H_2/O_2$ combustion flame. The ceramic surface was heated with burner flame and the bottom surface cooled with water flow. Also, the composition profile and the thickness of the graded layer were varied to study the thermo mechanical response. Furthermore, this study carried out the thermal stress analysis to investigate the thermal characteristics by the finite element method. Acoustic emission (AE) monitoring was performed to detect the microfracture process in a thermal shock test.

• Korean Journal of Pharmacognosy
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• v.18 no.3
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• pp.184-187
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• 1987

Fatty acids and sterols were isolated from petroleum ether extract of seeds of Acanthopanax sessiliflorum Seeman. Fatty acids were obtained from the saponified fraction and sterols from nonsaponified fraction of petroleum ether extract. Fatty acids were identified by gas liquid chromatography, and its composition was myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. The composition of sterols were determined by preparative TLC and gas liquid chromatography. It was confirmed to be a mixture of stigmasterol and ${\beta}-sitosterol$. These fatty acids and sterols were not previously reported from seeds of Acanthopanax sessiliflorum Seemann.