• The Korea Journal of Herbology
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• v.23 no.3
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• pp.61-66
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• 2008

Objecives : Aucklandiae Radix is a root of Aucklandia lappa which has been widely used for regulating the flow of vital energy, invigorating the spleen, alleviating pain. Aucklandiae Radix contains the costunolide which is the main ingredient. The substitutive Aucklandiae Radix are Inulae helenii Radix, Aristolchiae Radix, Vladimiriae Radix, and Inulae racemosi Radix in Korea and China. This paper is analysised and compared the costunolide and HPLC pattern in Aucklandiae Radix and substitute herbs. Methods : Chromatographic separation performed using C18 column(Luna 5 u, 250 mm ${\times}$ 4.6 mm) with a mixture of methanol and water(65:35)(v/v). The analyses detected at UV(210 nm). Results : Optimal extraction condition of costunolide was 100% methanol for 2hr. Costunolide was detected in Aucklandiae Radix and Vladimiriae Radix, but other herbs were not detected. In Korea herbal market, Aristolchiae Radix merchandise was identified as the imported Inulae helenii Radix. Conclusions : According to above results, this method was useful identified to Aucklandiae Radix and substitutive herbs. In Korea herbal market, Aristolchiae Radix was identified as Inulae helenii Radix.

• Korean Journal of Child Studies
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• v.16 no.2
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• pp.125-138
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• 1995

The purpose of the present research was to study developmental trends in categorical organization strategy. The subjects were 160 children - 40 nine - year - old boys, 40 nine - year - old girls, 40 seven - year - old boys, 40 seven - year - old girls. All subjects received one of three lists of items differing in category representativeness in either a free -recall or a sort -recall task. The selection of list materials permitted separation of the effects of age differences in category knowledge from those of knowledge per se on children's recall behavior. The tasks were administered to children individually with the memory task followed by the metamemory task. The data was analyzed with three - way ANOVA arid Pearson's correlation coefficient. The results were that (1) Children's recall, clustering, and metamemory increased with age, while age effects for clustering were restricted to the sort - recall/high typicality condition. At each age level, children showed higher level of recall, clustering and metamemory for category typical rather than atypical list, and sort - recall than free-recall. Level of clustering and metamemory were superior in the sort - recall task and for items of high category typicality. (2) 9 - year - old children were capable of deliberately and efficiently using category organization as a memory strategy at least when appropriate contextual support was present (as determined by task requirements and list materials: sort - recall/high typicality).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.251-253
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• 2017

Numerical study of air-blast type injector for low emission aircraft engines was conducted. Volume-of-fluids approach was used to track interface of fuel and air. Primary atomization of fuel stream was visualized, and thickness and mean velocity at the injector exit was calculated. Liquid fuel injected from fuel slots joined together as a thin film on preflimer surface, and interacted with swirling air. As instability on the fuel surface increased, separation of fuel as ligaments and droplets occured. The film thickness and velocity were used to as fuel injection boundary condition for reactive flow simulation. Primary reaction zone was formed in vicinity of the fuel nozzle, creating a stable flame inside the combustor.

• Steel and Composite Structures
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• v.18 no.3
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• pp.565-582
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• 2015

This paper is concerned with the dynamic analysis of simply-supported steel-concrete composite beams under moving loads. Considering the interface slip between steel girder and concrete slab, the governing motion equations are derived from the direct balanced method. By variable separation approach, the analytical solution of natural frequencies and mode shapes are obtained, as well as the orthogonal conditions. Then the dynamic responses of the composite beam under moving loads are analyzed, and compared with the experimental results. The analysis results show that the governing motion equations become more complicated when interface slip is taken into account, and the dynamic behaviors are significantly influenced by the shear connection stiffness. In the dynamic calculation of composite beams, the global stiffness should not be reduced as the same factor to all orders, but as different ones according to the dynamic stiffness reduction factor (DSRF), to which should be paid more attention in calculation, design and experiment, or else great deviation is inevitable.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.12
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• pp.769-775
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• 2011

Methane hydrate is formed by physical binding between water molecules and methane gas, which is captured in the cavities of water molecules under the specific temperature and pressure. $1m^3$ hydrate of pure methane can be decomposed to the methane gas of $172m^3$ and water of $0.8m^3$ at standard condition. Therefore, there are a lot of practical applications such as separation processes, natural gas storage transportation and carbon dioxide sequestration. For the industrial utilization of hydrate, it is very important to rapidly manufacture hydrate. So in this study, hydrate formation was experimented by adding THF and oxidized carbon nanotubes in distilled water, respectively. The results show that when the oxidized carbon nanofluids of 0.03 wt% was, the amount of gas consumed during the formation of methane hydrate was higher than that in the THF aqueous solution. Also, the oxidized carbon nanofluids decreased the hydrate formation time to a greater extent than the THF aqueous solution at the same subcooling temperature.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.571-580
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• 2016

In this paper, performance of the gas turbine combined cycle(GTCC) using pre-combustion carbon capture technology was comparatively analysed. Steam reforming and autothermal reforming were used. In the latter, two different methods were adopted to supply oxygen for the reforming process. One is to extract air form gas turbine compressor (air blowing) and the other is to supply oxygen directly from air separation unit ($O_2$ blowing). To separate $CO_2$ from the reformed gas, the chemical absorption system using MEA solution was used. The net cycle efficiency of the system adopting $O_2$ blown autothermal reforming was higher than the other two systems. The system using air blown autothermal reforming exhibited the largest net cycle power output. In addition to the performance analysis, the influence of fuel reforming and carbon capture on the operating condition of the gas turbine and the necessity of turbine re-design were investigated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.570-577
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• 1995

Aspergillus sp. SB-2704 was selected for its strong polygalacturonase activity among various strain of mold found in soil. It was found that production of polygalacturonase reached to maximum when the wheat bran medium containing 1% polypepton, 1% glucose, and 0.2% FeSO4 were cultured for 3 days at 35$^{\circ}C$. Polygalacturonase was purified 20.90 fold from Aspergillus SB-2704. The purification procedures include ammonium sulfate treatment, gel filtration on Sephdex G-150 and DEAE-cellulose ion exchange chromatography. Yield of the enzyme purification was 4.34%. Purified enzyme was confirmed as a single band by the polyacrylamide gel electrophoresis. When the purified enzyme was applied to SDS-polyacrylamide gel electrophoresis, the molecular weight was estimated to be 36,000. The optimum pH for the enzyme activity was 5.5 and optimum temperature was 5$0^{\circ}C$. The enzyme is stable in acidic condition. The activity of purified enzyme was inhibited by Pb2+, Hg2+ and Ba2+, whereas activated by Cu2+, Mn2+, Mg2+ and Fe2+. The activity of polygalacturonase was inhibited by the treament wit maleic anhydride, iodine, and EDTA. The result indicate the possible involvement of histidine and metal ion at active site.

• KSBB Journal
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• v.27 no.1
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• pp.33-39
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• 2012

In this study three major curcuminoids in turmeric curcumin (1), demethoxycurcumin (2) and bismethoxycurcumin (3) were efficiently extracted by optimizing extraction condition and simultaneously identified using a fast and reliable RP-HPLC-UV-MS and TLC method. The analysis by the $C_{18}$ column was performed and the UV wavelength was fixed at 425 nm. In this result, the total extraction yield of turmeric (Curcuma longa) was increased with extraction time from 1 to 7 h. So, optimum extraction time is 4 h. Also, the highest yield of extraction amount 0.433g 8.66% was obtained by ultrasonic waves with quarter frequency kHz and an extraction time of 7 h. The experiment method was consistent with theoretical Value $r^2$ = 0.987 (1), 0.997 (2) and 0.998 (3). Moreover, LC-MS analysis provided efficiently molecular weight information of three major curcuminoids in turmeric extracts and high purity (~95%) of the curcuminoids were obtained. This work offers would be useful for chemical and biological studies of natural plants and its products.

• Journal of the Korean Home Economics Association
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• v.29 no.1
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• pp.71-96
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• 1991

The purpose of this study was to identify kitchen space needs in regard to the architectural elements and facilities of rural houses. Three rural villages, Kum-Sung Ri, Young-San 1 Ri, and Yu-Bang 2.5 Ri were selected for this study. The present and past condition of the kitchen space was investigated by the field survey method. The major findings were that: 1) The interior floor materials of the kitchen had been changed from mostly mudplastered floor to linoleum, and the former low level of the kitchen floor had been lifted to the same level of the house plane. This change was made possible by the separation of the cooking from the heating system. 2) Western style kitchen, work centers and kitchen cabinets had been installed in the most of the rural houses. 3) On the basis of this study, the rural Korean kitchen space was classified into six types.

• Environmental Engineering Research
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• v.10 no.1
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• pp.38-44
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• 2005

Electro-thermal production of white phosphorus(WP, P4) generates substantial amount of highly toxic phossy water and sludges. Because of their high phosphorus contents and lack of reliable processing technology, large tonnages of these hazardous wastes have accumulated from current and past operations in the United States. In this study, two different methods for treatment of phosphorus sludge were investigated. These were bulk removal of WP by physical separation(froth flotation) and transformation of WP to oxyphosphorus compounds by air oxidation in the sludge medium. Kerosene, among other collectors, resulted in selective flotation of WP from the associated mineral gangue. Solvent action of kerosene occurring on the WP surface(by rendering WP particles hydrophobic) might produce the high selectivity of WP. The WP recovery in the froth was 79.3% from a sludge assaying 34.2% of WP. In the oxidation study, air gas was dispersed in the sludge medium by the rapid rotation of the impeller blades. The high level of sludge agitation intensity caused a fast completion of the oxidation reactions and it resulted in the high percentage conversion of WP to PO4-3 with PO3-3 making up almost all portion of oxyphosphorus compounds. The WP analysis on the treated sludge showed that supernatant solution and solid residue contained an average of 4.2 μg/L and 143 ppm respectively from the sludge containing about 26 g of WP. Further investigation will be required on operational factors to better understand the processes and achieve an optimum condition.