• Korean Journal of Pharmacognosy
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• v.26 no.1
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• pp.31-39
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• 1995

In order to investigate the chemical and pharmacological characterization of crude drug processing, the triterpenoidal constituents of Glycyrrhizae Radix(GR) were examined. Processed GR has been often used to reinforce and change the efficacy of GR. Glycyrrhizin(GL) is one of the main constituents of GR. Following procedure described in the oriental medicinal reference, GR and GL were heated at $140^{\circ}C{\sim}240^{\circ}C$ in GC oven. And then, the content of GL in the processed GR and GL was analyzed by HPLC. GL was transformed to $18-{\beta}-glycyrrhetic\;acid\;mono-{\beta}-D-glucuronide(GM)$ and glycyrrhetic acid(GA) by processing at $170^{\circ}C$. Determination of the content of GL increasing the heating temperature showed that GL was decomposed by heat above $150^{\circ}C$. It was also found that the content of GL in GR processed by heat above $170^{\circ}C$ remakeably decreased.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.3
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• pp.375-383
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• 2009

This study was conducted to measure the total polyphenol contents and DPPH radical scavenging activities of different potato plants parts, varieties, and grades, and by distribution and different cooking conditions. The results were as follows. For the plant parts, total phenolic content and DPPH radical scavenging activity were highest in the flowers followed by leaves and stems, respectively. Among 5 potato varieties, 'Jasim' had the highest DPPH radical scavenging activity and the activity of its pulp was lower than that of its cortex(peel). Regardless of potato grade, the cortexes(peel) of samples had two-fold higher DPPH radical scavenging activity than pulp, and the Grade SS potato had the highest phenolic content. It was also found that the bud ends and stem ends had comparably larger amounts of phenolic compounds in horizontally cut potatoes. Finally, the descending order for DPPH radical scavenging activity, according to different cooking conditions, was as follows: gas oven range-baking, frying, microwave-heating, sauteing, boiling in 1% saline solution, steaming, and boiling in 3% saline solution.

• Journal of the Korean Chemical Society
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• v.20 no.5
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• pp.417-423
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• 1976

Corona treatment of PE, PP and PVC showed a dramatic increase of bond strength when lap joints were made between the polymers and aluminum plates. Heating the corona-treated PE and PP, and PVC in a drying oven at 80 and $50^{\circ}C$, respectively, for 15 min reduced the bond strength to about a half of that of corona-treated but unheated polymers, which indicated that the increase of bond strength was not due to oxidation of the polymer surface. The Weibull distribution function was employed to check reliability of the scattered data obtained from testing the lap joints. It is speculated that electron was deposited on the corona-treated polymer surface to enhance bond strength with aluminum.

• Resources Recycling
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• v.5 no.4
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• pp.17-24
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• 1996

The computer simulation model was established to verify the applicability of smelting reduction concept to treatment of industrial wastes which becomes issue on the enviromental and recycling view point. Computer simulation model provides as following results. The increase of post combustion ratio(PCR) and heat transfer efficiency of PC energy(HTE) is effective ways to save energy. But, in order to increase PCR, recovery efficiency of post combustion energy(HTE) have to be higher than 85% HTE considering refractory life and saving energy together. Coke is most useful fuel source because it shows lowest dependence of PCR and low hydrogen content. The quality of hot metal of current process would be expected to the similar level with that of blast furnace. The utilization of scrap and Al dross can be also possible to maximize the advantages of current process which is high temperature and chemical dilution with hot metal and slag. In case of scrap, energy consumption was slightly increases because of heating up energy of scrap. Consquently, current process concept provides the possibility of intergrating recycles of industrial wastes materials such as EAF slag, coke oven dust, life terminated acidic refractory, aluminium dross and scrap by smelting reduction process.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.2
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• pp.99-108
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• 2018

This paper presents a design study of a solid state power oscillator to replace the conventional magnetron. The operational conditions of a single-stage 300 W LDMOS power amplifier were fully characterized. The power module consisted of two amplifiers connected in parallel. A delay-line feedback loop was designed for self-oscillation. A phase shifter was inserted in the delay-line feedback loop for adjusting the round-trip phase. Experiments performed using the power oscillator showed an output power of 800 W and a DC-RF conversion efficiency of 58 % at 2.327 GHz. The measured results were in good agreement with those predicted by numerical simulations.

• The Korean Journal of Food & Health Convergence
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• v.5 no.5
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• pp.11-25
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• 2019

Extraction of oil from Moringa oleifera seed using Response Surface Methodology (RSM) was investigated. Effects of three factors namely: sample mass, particle size and extraction time on the response, Moringa oleifera a volume extracted, were determined. The Box-Behnken design of RSM was employed which resulted in 15 experimental runs. Extraction was carried out in a 250 ml Soxhlet extractor with Hexane and Ethanol as solvent. The Moringa oleifera seed powder was packed inside a muslin cloth placed in a thimble of the Soxhlet extractor. The extraction was carried out at 60℃ using thermostatic heating mantle. The solvent in the extracted oil was evaporated and the resulting oil further dried to constant weight in the oven. This study demonstrates that Moringa oleifera oil can be extracted from its seed using ethanol and acetone as extraction solvent. The optimum process variables for both solvent (ethanol and acetone) was determined at sample weight of 40 g, particle size of 325 ㎛ and extraction time of 8 hours. It can be deduced that using acetone as solvent produces a higher yield of oil at the same optimum variable conditions compared to when ethanol was used.

• Korean journal of food and cookery science
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• v.10 no.3
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• pp.232-237
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• 1994

A Texture profile for frozen pizzas was developed and applied to a comparison of the texture of frozen pizzas heated by conventional and microwave ovens. The texture profile consisted of 29 attributes evaluated at the following five stages: visual and manual. lip feel, first bite, mastication, and swallowing. The microwave pizza tended to be more crisp, dry, and rough but less tender than the conventionally heated pizza. Separate evaluations of the center and edge portions showed differences only in top greasiness, wetness of sauce on palate, moisture release for both types of pizza suggesting that the separated evaluations were not necessarily required. The edge tended to be less greasy and moist than the center possibly because it is more susceptible to overcooking and subsequent drying out.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.673-679
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• 2009

To develop ready-to-eat (RTE) style Korean traditional Galbi-jjim, the optimal conditions for sous-vide cooking and cookchill preparation and the sensory properties of the cooked products were investigated. During heating, the meat core temperatures reached $85^{\circ}C$ within 30 min and 45 min when a water bath and combination oven were used, respectively. Chilling to $3^{\circ}C$ within 45 min was conducted to meet the standards for microbiological safety set by the UK Department of Health and Social Security (DHSS) Guideline. Galbi-jjim that was vacuum-cooked in a water bath was much more tender than that of Galbi-jjim prepared using the cook-chill method, but had no difference in any reheating methods. The average sensory scores of juiciness and the overall acceptance of Galbi-jjim were significantly higher when water bath cooking was used, and there were no differences in reheating methods. In conclusion, the serial methods of sous-vide processing and rapid chilling can be applied to produce RTE traditional Galbi-jjim, and this can be conducted while meeting the standards specified in safety guidelines.

• Journal of the Korean Wood Science and Technology
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• v.49 no.3
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• pp.226-233
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• 2021

This article aimed at thermally treating and charactering the Eucalyptus grandis wood under three different temperatures. For this, pristine eucalypt samples were treated by heating in a laboratory oven at 160 ℃, 200 ℃ and 240 ℃, always for 2 h. Treatment parameters (based on weight percentage loss and specific gravity), as well as mechanical (by hardness tests), chemical (by infrared spectroscopy), thermal (by thermogravimetry), and colorimetric (by CIELab method) features were evaluated. Compared to the pristine ones, the treated woods have there was a drop in apparent density at 12 % and consecutively greater thermal stability which is probably related to a previous partial degradation of some major amorphous components (namely cellulose, hemicellulose and lignin), as suggested by the treatment parameters and infrared spectra. Besides of that, the higher the temperature treatment, the higher the loss in surface hardness and the higher the colour darkening.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.2
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• pp.83-92
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• 2019

Spontaneous combustion propensity of various coals of carbonization grade as a pulverized fuel of coal-fired power plant has been tested from an initial temperature of $25^{\circ}C$ to $600^{\circ}C$ by heating in an oven with air to analyze the self-oxidation starting temperature. These tests produce CPT (Cross Point Temperature), IT (Ignition temperature), and CPS (Cross Point Slope) calculated as the slope of time taken for a rapid exothermic oxidation reaction at CPT base. CPS shows a carbonization rank dependence whereby wood pellet has the highest propensity to spontaneous combustion of $20.995^{\circ}C/min$. A sub-bituminous KIDECO coal shows a CPS value of $15.370^{\circ}C/min$, whereas pet coke has the highest carbonization rank at $2.950^{\circ}C/min$. The nature of this trend is most likely attributable to a concentration of volatile matter and oxygen functional groups of coal surface that governs the available component for oxidation, as well as surface area of fuel char, and constant pressure molar heat.