• Korean Journal of Agricultural Science
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• v.40 no.1
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• pp.13-18
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• 2013

Effect of electric pulse stimulation was tested on the fruit body formation of valuable mushroom Tricholoma matsutake in the field of natural habitat of this mushroom. After applying the electric stimulator to the specific area of pine forest we found that the treatment especially stimulated the fructification of T. matsutake. And the most valuable findings of our study was that only our treatment plots showed fruit body formation whereas the control plots and the whole natural habitats of our study area showed zero production of this mushroom during the same time. From the point of view of mushroom production, our experiment shows that fruit body production can be upgraded by using pulsed power as an electrical stimulation in the field of the natural habitat of this mushroom. These findings from our experiment confirm the effectiveness of the significance of pulsed power technology for the improvement of T. matsutake fruit body production in the natural habit of this mushroom.

• Journal of Korean Clinical Health Science
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• v.4 no.4
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• pp.730-736
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• 2016

Purpose. The aim of this study was to provide Aromatherapist with analysis of the effect of natural aroma essential oil on middle school students' self-concept. Methods. In total, 20 students were recruited to answer a self-administered questionnaire in pre and post. The questionnaire was composed of questions about general self-concept, class self-concept, achievement self-concept, ability self-concept, social self-concept, family self-concept, emotional self-concept, physical self-concept. The natural aroma essential oil program was operational in a 90-minute once a week for ten weeks. Results. As a result, the score of emotional self-concept(t=-2.60, p<.05) is higher than pre the experiment post experiment. Conclusions. This study is to get a basic data of natural aroma should be applied to improve self-concept of middle school students.

• Journal of the Korean Applied Science and Technology
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• v.22 no.3
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• pp.241-249
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• 2005

This experiment extracted the natural green-tea using ethanol and obtained the refined oil component after filterated green-tea extract. This study tested the antimicrobial effect as characteristics experiment, and analyzed refined oil component with pH-meter and GC/MS. In the result of this experiment, it obtained the next conclusions. In the first result of extraction experiment, it could know that extraction ratio of refined oil component appeared about 9.0%. In the second result of characteristics experiment, it could certificate that in case of increasing the refined oil component in concentration of 100ppm and above, and according to passage of cultivation time, the number of S-aureus and E-coli in microbe decreased less and less. But in case of blank test not adding the refined oil component, the number of microbe increased more and more. In these phenomena, it could certificate that refined oil component of green-tea appeared antimicrobial effect against microbe. In the third result of instrumental analysis, refined oil component of green-tea appeared about 7.6 in 1% distilled water solution with pH-meter, and the aromatic components of benzene, bonyl acetate, campene, ${\alpha},{\beta},{\gamma}$-pinnene etcs from refined oil component of green-tea was detected with GC/MS.

• Bulletin of the Korean Chemical Society
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• v.14 no.5
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• pp.554-556
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• 1993

A chemical investigation of the stem bark of Melia azedarach var. Japonica (Meliaceae) has led to a new limonoid, 12-hydroxyamoorastatone (1), whose structure has been elucidated by spectroscopic measurements including 2D-NMR. The 2D-NOESY experiment on its di-p-bromobenzoate derivative (1a) has established the relative configuration of 1.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.489-492
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• 2001

There were many reports on the natural antioxidants, but only tocopherol has been widely used despite of its high market price because of its recognized safety. On the other hands, antimicrobial effects of various plant extracts also have been extensively studied. There exist many substances showing antimicrobial activity in plants and their activities have been studied.

• Proceedings of the Korean Society of Crop Science Conference
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• 1996.05a
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• pp.88-89
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• 1996

• Proceedings of the Korean Society of Crop Science Conference
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• 1992.05a
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• pp.26-27
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• 1992

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.2
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• pp.94-94
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• 1999

Natural gas is considered to be on e of the most promising candidates for a clean substitute fuel and a great amount of research on the compressed natural gas(CNG) fueled vehicle has been performed. In this s tudy, we try to understand the property of CNG fuel with using CNG engine experiment. In order to present the direction and application of CNG, we experiment with various operating conditions that is, spark timing, A/F ratio, air quantity and fuel quantity, etc. 11,967 cc engine was used in the experiment and the engine fuel ratio was determined in the way that the performance of dedicated CNG engine is corresponded to that of existing diesel engine. The performance and dedicated CNG engine were measured by changing the fuel injection timing. The dedicated CNG engine was proved to be good in describing the experimental results and according to the actual road test, acceleration and constant speed driving for dedicated CNG engine was better than existing diesel engine.

• Journal of Food Hygiene and Safety
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• v.7 no.2
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• pp.99-106
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• 1992

To prevent food-poisoning outbreaks by Vibrio vulnificus the antimicrobial efficacy of grapefruit seed extract (GFSE) was examined. Minimal inhibitory concentration (in vitro) for the microorganism was found to be 50∼100 ppm. Transmission electron micrographs of Vibrio vulnificus showed the biocidal action of this natural antimicrobial agent would be related to specific respiratory effect coupled with the destruction of permeable function of microbial cell membrane. After Anguilla japonica GFSE-injected to the body was incubated in the seawater contaminated by Vibrio vulnifiucs the fish meats were taken up, mixed with control diet and used as a diet in the feeding experiment. In this experiment the effect of GFSE treated with fish muscle on body weight, protein efficiency ratio, serum enzymes and serum blood components of broiler chicks was investigated. It is proved from this study that there is neither Vibriosis nor toxicity associated with GFSE itself an fish meats treated with it when it is injected to the fish body at a level of 250 ppm or less.

• Journal of Labour Economics
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• v.32 no.3
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• pp.91-121
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• 2009

Utilizing the fact that student allocation to private or public high schools in Korea is done randomly within a given school district, this study conducted a natural experiment, free from selection bias, to analyze whether private schools are more effective than public schools in terms of enhancing students' academic performance. After analyzing a model that controls the fixed effects of school districts, it was found that private schools do not have a statistically significant impact compared to public schools with respect to improving academic records. Nevertheless, the private school effect has shown a positive value equivalent to 0.13 standard deviation for female students at the highest academic levels.