• Journal of Energy Engineering
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• v.11 no.2
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• pp.81-89
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• 2002

IGCC (Integrated Coal Gasification Combined Cycle) is a technology that generates electric power using coal gasification and gasified fuel. Carbon conversion value of IGCC is higher and the influence on the environment is lower than the pulverized coal power plant. Especially, in the nations where the weight of fossil fuel for power generation is remarkably high like in Korea, IGCC stands out as an alternative plan to cope with sudden limitation for the emissions. In this paper, system design study for the commercial IGCC system which the introduction is imminent to Korea was performed. Two cases of entrained gasification process are adapted, one is FHR(full heat recovery) type IGCC system for high efficiency and the other is Quench type IGCC system for low cost. System simulations using common codes like AspenPlus were performed for each system. In the case of Quench system, system option study and sensitivity analysis of the air extraction rate was performed. Thermal performance result for the FHR system is 42.6% (HHV, Net) and for the quench system is 40% (HHV, net) when 75% air is extracted.

• Economic and Environmental Geology
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• v.12 no.4
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• pp.207-221
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• 1979

The studied area occupies the southern part of Haenam peninsula located in the southwestern corner of Korea. The stratigraphic sequences of the area are grouped into following three units in ascending order. (1) Late Cretaceous sedimentary rocks of Uhangri Formation which consist of the alternative beds of black shales and tuffaceous sediments, Hwangsan acidic fine grained tuffs and Jindo rhyolite flows. (2) Late Cretaceous biotite granite and acidic porphyries which intruded the Late Cretaceous sedimentary rocks. (3) Tertiary(?) pitchstone. The study purposes to delineate any of geochemical aspects on the deposition of the sequences, the average amounts of organic materials and the effect to the maturation of hydrocarbonization which has been occured by the intrusives. Sixty nine black shale samples were collected from Uhangri Formation in the northern and southern coasts of the peninsula. Organic carbons, total extracted organic matters and hydrocarbons were mainly determined by the Soxhlet extraction method, together with C-H-N elemental analyses. Based on the field and laboratory studies, the following interpretations have been obtained. (1) The paleohydrostatic condition of the sedimentation which took place was relatively calm and stable to delineate a lacustrine environment. (2) The amounts of organic material were more or less constant throughout the period of the deposition of the sediments. (3) The degree of hydrocarbonization of the Uhangri Formation in the northern coast was taken place higher than that in the southern coast due to the differences of thermal effect by the biotite granite which is assumed to be as a heat source in the area. Among the northern coast, some black shales in Uhangri and Mogsam areas which had been under the most moderate temperature environment snow symptomatic oily material, whereas, those in Sinseongri area do not, which were presumably to be intensive thermal alteration by the later acidic porphyries.

• KIEAE Journal
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• v.16 no.6
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• pp.109-114
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• 2016

Purpose: The underground air is the warm air discharged from the porous volcano bedrock 30-50m underground in Jeju, including excessive humidity. The temperature of the underground air is $15-20^{\circ}C$ throughout the year. In Jeju, the underground air was used for heating greenhouses by supplying into greenhouses directly. This heating method by supplying the underground air into greenhouses directly had several problems. The study was conducted to develop the heat pump system using underground air as heat source for resolving excessive humidity problem of the underground air, adopting the underground air as a farm supporting project by Ministry of Agriculture, Food and Rural Affairs(MAFRA) and saving heating cost for agricultural facilities. Method: 35kW scale(10 RT) heat pump system using underground air installed in a greenhouse of area $330m^2$ in Jeju-Special Self-Governing Province Agricultural Research & Extension Services, Seogwipo-si, Jeju. The inlet and outlet water temperature of the condenser, the evaporator and the thermal storage tank and the underground air temperature and the air temperature in the greenhouse were measured by T type thermocouples. The data were collected and saved in a data logger(MV200, Yokogawa, Japan). Flow rates of water flowing in the condenser, the evaporator and the thermal storage tank were measured by an ultrasonic flow meter(PT868, Panametrics, Norway). The total electric power that consumed by the system was measured by a wattmeter(CW240, Yokogawa, Japan). Heating COP, rejection heat of condenser, extraction heat of evaporator and heating cost were analyzed. Result: The underground air in Jeju was adopted as a farm supporting project by Ministry of Agriculture, Food and Rural Affairs(MAFRA) in 2010. From 2011, the heat pump systems using underground air as a heat source were installed in 12 farms(16.3ha) in Jeju.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.150-157
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• 2009

The purpose of this study was to analyze the anthocyanin contents of black soybean crude extracts derived using a countercurrent system and to compare the effects of stabilizers(${\beta}-cyclodextrin$, maltodextrin) and sugars(sucrose, maltose) on the color deterioration of the anthocyanin. When the extraction process was kept at 100$^{\circ}C$ for 120$\sim$180 min, only C3G (cyanidin-3-glucoside) was detected in the water extract. The C3G contents in the water extracts acquired at 8$^{\circ}C$, 60$^{\circ}C$, and 80$^{\circ}C$ were 2.38 ppm, 1.73 ppm, and 1.73 ppm, respectively. Sucrose and maltose retarded color deterioration of the crude pigment extract by the countercurrent method with methanol. Finally, the additions of maltodextrin or ${\beta}-cyclodextrin$ did not retard thermal color deterioration of the black soybean crude pigment extract.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.641-648
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• 2010

The objective of this study was to evaluate the pre-heating treatment effects on the antioxidant properties of ethanolic garlic and onion extracts. Garlic and onion with or without heating ($100^{\circ}C$, 30 min) were extracted with ethanol, and the total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, iron chelating ability, reducing power, and antioxidant activity in a linoleic acid emulsion system were evaluated. Garlic (41%) had a higher drying yield than onion (11%). Regardless of pre-heating, ethanol extracts of onion resulted in an approximately 25-fold higher yield than those of garlic. Thermal treatment before extraction decreased the levels of ethanol-soluble phenolics for both garlic and onion. Regardless of pre-heating, the radical scavenging abilities of ethanol extracts from garlic were greater than the ethanol extracts from onion. The iron chelating abilities of ethanol extracts from fresh and heated garlic were 85 and 81% at 10 mg/mL, respectively, whereas those of onion extracts were 10 and 9% at the same concentration, respectively. However, no differences in reducing power between garlic and onion extracts were observed. Both garlic and onion inhibited the formation of hydroperoxide in linoleic acid emulsion systems when ethanol was used as a solvent. Overall, garlic extracts had greater antioxidant activity than onion extracts, and the antioxidant activity of garlic and onion extracts were not significantly affected by thermal treatment.

• Journal of Powder Materials
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• v.1 no.1
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• pp.72-78
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• 1994

Two kinds of $U_3Si$ powders and $U_3Si$ dispersed nuclear fuel meats have been prepared by conventional comminution process and a newly developed rotating disk atomization process. In contrast to angular shape and broad size distribution of the conventionally processed powder, the atomized powder was spherical and showed narrow size distribution. For the atomized powder, the heat treatment time for the formation of $U_3Si$ by a peritectoid reaction was reduced to about one tenth, thanks to microstructure refinement by rapid cooling of about 5$\times$104 K/s. The extruding pressure of atomized $U_3Si$ powder and Al powder mixture was lower than that of comminuted $U_3Si$ and Al powder mixture. The elongation of the atomization processed fuel meats was much higher than that of the comminution processed fuel meats and remained over 10% up to 80wt.% of $U_3Si$ powder fraction in the fuel meats. It appears therefore that the loading density of $U_3Si$ in fuel meat can be increased by using atomized $U_3Si$ powder. The atomized spherical particles were randomly distributed, while the comminuted particles with angular and longish shape were considerably aligned along the extrusion direction. Along the transverse direction of the extraction the electrical conductivity of the atomization processed fuel meats was appreciably higher than that of comminution processed fuel meats. This tendency became pronounced as $U_3Si$ content increased. Because the thermal conduction which is believed to be proportioned to the electrical conduction in the nuclear fuel meats occurs in radial direction, the atomization processed fuel can be better used in research reactors where high thermal conductivity is required.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.81-88
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• 2015

Various satellite sensors having ranges of the visible, infrared, and thermal wavelengths have been launched due to the improvement of hardware technologies of satellite sensors development. According to the development of satellite sensors with various wavelength ranges, the fusion and integration of multisensor images are proceeded. Image matching process is an essential step for the application of multisensor images. Some algorithms, such as SIFT and SURF, have been proposed to co-register satellite images. However, when the existing algorithms are applied to extract matching points between optical and thermal images, high accuracy of co-registration might not be guaranteed because these images have difference spectral and spatial characteristics. In this paper, location of control points in a reference image is extracted by SURF, and then, location of their corresponding pairs is estimated from the correlation of the local similarity. In the case of local similarity, phase correlation method, which is based on fourier transformation, is applied. In the experiments by simulated, Landsat-8, and ASTER datasets, the proposed algorithm could extract reliable matching points compared to the existing SURF-based method.

• Clean Technology
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• v.8 no.1
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• pp.11-17
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• 2002

Petcokes is the final product obtained from a refinery process. This petcokes includes high percentage of inorganic and sulfur compounds. Currently, the petcokes produced from domestic refinery plants include more than 6% of sulfur. To use petcokes as valuable raw materials, the weight percentage of sulfur must be lower than 2% of sulfur. Solvent extraction, thermal desulfurization, and hydro-desulfurization have been used to remove the sulfur. In this study, we attempted new approach to remove the sulfur introducing microwave energy. Microwave increase the reaction rates by providing the fast heating and disconnecting the bonding structure of the molecules. The experiments of microwave thermal desulfurization and microwave plus hydrogen gas were carried out to remove the sulfur. We obtained 68.3% of sulfur removal rate with the 2 hours of reaction time and 1835 W of microwave powder. In the experiment of microwave with hydrogen gas, we obtained 86.4% of sulfur removal rate with the 1.5 hours of reaction time and 1835 W of microwave power. If we increase reaction time or decrease the particle size of petcokes, we expect more than 90% of sulfur removal.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.2
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• pp.174-184
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• 1993

This is to investigate the methodology for the simultaneous determination of Wk, mk and TSNA using gas chromatography(GC) in combination with chemiluminescence detector, thermal energy analyzer(TEA) . The simultaneous analysis has been estimated by evaluating tobacco. The TEA was linked to GC equipped with non -polar SPB -5 fused silica capillary column which was introduced into the ceramic pyrolysis tube by the point of 16cm from the end of TEA. Quantification was carried out by internal standardization with WDPA after calibration of retention times and response factors with authentic nitrosoamines. It was demonstrated that WDPA was most preferable as internal standard for the simultaneous analysis. The recoveries of the internal standard were in the range of 83∼96% . Nitrosoamines in this method were detected with determination limit of 0.1ng and was made by a straight line in calibration curve by TEA response. The suitability of nitrosoamines extraction in tobacco leaf was investigated. It was most suitable to extract nitrosoamines from tobacco leaves with 0.01 M NaOH within a period of 8 hours. Thimerosal as an antibacterial agent was added to NaOH solution to prevent artifactual formation. The fractionation and the purification of nitrosoamines form alkaline extracts were conveniently performed using Extrelut multilayer column and dichloromethane. Reproducible and reliable results were obtained for the determination of nitrosamines in a relatively short time compared to previous known method. TSNA contents in burley were about 4 times higher as those in the fluecured tobacco.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.2
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• pp.46-55
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• 2016

The kinetic analysis of a heavily aluminized cyclotrimethylene-trinitramine(RDX) is conducted using differential scanning calorimetry(DSC), and the Friedman isoconversional method is applied to the DSC experimental data. The pre-exponential factor and activation energy are extracted as a function of the product mass fraction. The extracted kinetic scheme does not assume multiple chemical steps to describe the complex response of energetic materials; instead, a set of multiple Arrhenius factors is constructed based on the local progress of the exothermic reaction. The resulting reaction kinetic scheme is applied to two thermal decomposition tests for validating the reactive flow response of a heavily aluminized RDX. The results support applicability of the present model to practical thermal explosion systems.