• The Journal of Engineering Geology
• /
• v.30 no.4
• /
• pp.557-575
• /
• 2020

Plasma blasting which is generated by high voltage arc discharge of electricity is applied to soil mass to improve permeability of soil and cleaning efficiency of oil contamination. A new high voltage generator was manufactured and three types of soil including silty sand, silty sand mixed with lime and silty sand mixed with cement were prepared. Small and large soil columns were produced using these types of soil and plasma blasting was performed within soil columns to investigate the variation of soil volume penetrated by fluid and permeability. Soil volume penetrated by fluid increased by 11~71% when plasma blasting was applied in soil. Although plasma blasting with low electricity voltage induced horizontal fracture and fluid penetrated along this weak plane, plasma blasting with high voltage induced spherical penetration of fluid. Plasma blasting increased the permeability of soil. Permeabilty of soils mixed with lime and cement increased by 450~1,052% with plasma blasting. Permeability of soil increased as discharge voltage increased when plasma blasing was applied once. However, several blastings with the same discharge voltage increase or decrease permeability of soil. Oil contaminated soil was prepared by adding diesel into soil artificially and plasma blasting was performed in these oil contaminated soil. Cleaning efficiency increased by average of 393% for soil located nearby the blasting and by average of 239% for soil located far from the blasting. Cleaning efficiency did not show any correlation with discharge voltage. All these results indicated that plasma blasting might be used for in-situ cleaning of oil contaminated soil because plasma blasting increased permeability of soil and cleaning efficiency.

• (The) Research of the performance art and culture
• /
• no.34
• /
• pp.315-353
• /
• 2017

This study examined the music policies of the three kings, Seongjong, Jungjong, and Injo, who were in power for about 200 years from the late 15th century to the early 17th century. These three kings deserve attention in musical history for different reasons. Sungjong published "Gugjooryeui"(1474), "Gyeong-gugdaejeon"(1476), and "Aghaggwebeom"(1493), the typical etiquette books, law books, and musical books that take the most important position in the history of Joseon, so his direction of music policy deserves attention. Jungjong was the king who rose to the throne after there was a revolt against Yeonsangun's tyranny. Injo ascended to the throne by starting a military coup d'etat himself. One may wonder how the aspect of music policies developed by a king, who was crowned by a revolt, is different from other cases. As each of these three kings had different background of enthronement and the contents of music policies in the royal family also developed with different emphasis, this study examined each aspect separately. Sungjong emphasized the importance of music and regarded it important to cultivate officials who know music. To this end, he gave a special order to Yejo(the office of protocol) and this study tried to clarify the contents first. In addition, this study examined the process, contents, and meaning of various modification works related to the revision of the lyrics used in the ceremonies. Jungjong supplemented the institutional aspects of music. This is the result of expressing the will to correct the anomalous and reckless music policies of the period of Yeonsangun. In addition, many words in the lyrics had been about Buddhist doctrines and love songs between male and female, so there were efforts to reform these. As for the period of Injo, this study examined the music policies that were made in the process of resolving the crisis after the war. It was a time when court musicians were scattered after two times of war and it was not possible to hold the national ritual properly, so music policies in this period were different from the ones in stable era. This study covered discussions on the measures to collect lost instruments and scattered musicians. It also looked at how the restoration effort was made in the situation that the music used in ancestral rites was abolished.

• (The) Research of the performance art and culture
• /
• no.32
• /
• pp.31-70
• /
• 2016

Jongmyo Jeryeak [Royal ancestral shrine music] is a precious cultural heritage, which has been played till now since two great kings Sejong and Sejo who made it. But going through Japanese occupation, Jongmyo Jeryeak has been changed into a music totally different from the music the two kings intended. And the changed Jongmyo Jeryeak is being played these days. The original Jongmyo Jeryeak, which was made by the two kings, remains in old music scores. Therefore there is a need to investigate the differences between the original and current Jongmyo Jeryeak by interpreting the old music scores and recovering the original. This paper recovers the origianl Jongmyo Jeryeak from the music score Daeakhubo and compares it with the current Jongmyo Jeryeak. The results are as follows. The origianl Jongmyo Jeryeak is a set of common songs made with Hyangak and Gochiak to sing the verses which extol royal ancestors' virtues. All of the musical elements are matched with the verses so that the meaning of the verses is transmitted naturally. Jangdan musical time musical structure are matched with the structure of verses, and the musical motif of the songs is matched with the meaning of the verses. The music, which is easy and expresses the meaning of the verses well, demonstrates King Sejong's talent as a musician. The current Jongmyo Jeryeak is a set of special songs in which Sigimsae is emphasized rather than the meaning of the verses. The melodies are broken into pieces inconsistently, the meaningless word 'ae' is added thoughtlessly, and Jangdan musical time musical structure are unrelated to the verses. Therefore the meaning of the verses is not transmitted at all. These changes, which were made during the period of Japanese occupation, seem to desecrate the verses of the original songs. The melodies, which are broken into pieces inconsistently, revive into the current mysterious ritual music through Sigimsae. But in order to be a proper ritual music, some corrections have to be made to convey the meaning of the verses.

• Korean Journal of Comparative Education
• /
• v.27 no.4
• /
• pp.255-283
• /
• 2017

The purpose of this study is to analyze the comtent of the education system of US and the UK in order to build an integrated system that can develop the leadership competency of preschool principle. Based on this, the implications are as follows. First, competencies can developed through learning rather than fixed. Therefore, re-conceptualization of leadership competence appropriate to the characteristics and organization of the individual as the presiding authority of the preschool can be considered as ability to show visible knowledge and skills, invisible self concept. Therefore, it is necessary to establish a capacity development plan based on this. Second, the introduction and implementation of continuous and systematic training programs such as the training system that strengthens the capacity of the directors and principals of the United States and the United Kingdom is necessary. To do this, we must introduce a system that renews certification every five years, like the United States, rather than a system that acquires and maintains certification with a single training. Third, various training methods should be carried out. In the case of the US and the UK, we think it is desirable to train in various ways in the training period, the university, the teacher center, and the private organization or association. Therefore, it is necessary to build a cooperation system with various institutions such as training institutes, universities, teacher centers, educational information research institutes, and private organizations in each province, and strengthen them in various ways. Fourth, the contents and methods of qualification training and future job training of the director of the preschool should be deviated from the uniform level. Therefore, the systematic research that reflects the knowledge and contents of the administration required in the field should be given priority by the university or research organization that is in charge of the training.

• New Physics: Sae Mulli
• /
• v.68 no.12
• /
• pp.1293-1301
• /
• 2018

The basic magnetic properties of commercially available High-$T_c$ Superconductor (HTS) GdBCO-coated conductor (GdBCO-CCs) were investigated by using physical property measurement system-vibrating sample magnetometer (PPMS-VSM). From the zero-field-cooled (ZFC) m(T) curve, the $T_c$ was found to be ~93 K. After removing the background m(H) data, we obtained both the net m(H) data and the ${\Delta}m_{irr}$. The $H_{irr}(T)$ coincided very well with the power-law relation $H_{irr}=H_{irr}(0)(1-T/T_c)^n$ with $$n{\sim_=}1.19$$. The magnetic flux behavior was investigated by using the ${\delta}$ values in the relationship $J_c{\propto}{\Delta}m_{irr}{\propto}H^{-{\delta}}$. A ${\delta}{\approx}0$ region denoting an independent magnetic flux pinning effect, a ${\delta}{\approx}0.6{\sim}1.2$ region representing a collective flux pinning effect due to the interaction, and a ${\delta}{\gg}2$ region representing freely moving magnetic fluxes caused by the Lorentz force were observed. The boundary line between ${\delta}{\approx}0$ and ${\delta}{\approx}0.6{\sim}1.2$ is denoted by a $H_1$, and the one between ${\delta}{\approx}0.6{\sim}1.2$ and ${\delta}{\gg}2$ is denoted by a $H_2$. The ${\delta}(T)$ was obtained in the region of $H_1$ < H < $H_2$. As the temperature was decreased, the ${\delta}$ value gradually decreased.

• Journal of Life Science
• /
• v.31 no.5
• /
• pp.488-495
• /
• 2021

The aim of this study was to investigate the possible antioxidant effect of Spirodela polyrhiza (SP) on rats fed a high fat and high cholesterol diet supplemented with either 5% (SPA group) or 10% (SPB group) SP for 4 weeks. The hepatic SOD activity of the HF group significantly decreased compared to that of the N group, but that of the SPA and SPB groups significantly increased. The GPx activity of the SPA and SPB groups in the liver was significantly greater than that of the HF group, and the hepatic catalase activity of the SPA and SPB groups significantly increased compared to the HF group. The hepatic superoxide radical content of the mitochondria and microsomes of the HF group significantly increased compared to that of the N group, but the contents were reduced in the group that took SP powder. The hepatic hydrogen peroxide content in the cytosol and mitochondria of the SP powder group was lower than in the HF group. The carbonyl content in the mitochondria and microsomes of the SPA and SPB groups was significantly lower than in the HF group. The TBARS values in the liver significantly decreased in the SPA and SPB groups. Spirodela polyrhiza was thus effective in reducing oxidative stress by regulating the hepatic antioxidant enzymes and the free radicals in rats fed high fat and high cholesterol diets.

• Journal of Life Science
• /
• v.31 no.5
• /
• pp.475-480
• /
• 2021

Interest in edible insects such as Protaetia brevitarsis has increased rapidly, and several insect producers use these insects in industrialized mass production. However, mass rearing of insects can cause insect diseases. Sprouted barley is a valuable source of nutrients and has antioxidant, antimicrobial, anti-inflammatory, and anti-cancer effects. This study was conducted to investigate the effect of sprouted barley as a feed additive for producing healthy P. brevitarsis larvae. P. brevitarsis larvae were fed feeds with or without sprouted barley, and their body weight and larval period wewe checked weekly. To confirm the antibacterial effects of sprouted barley, in vitro bioassays were performed by counting Serratia marcescens colonies, and in vivo bioassays were performed by determining the survival rate and body weights of the S. marcescens-infected larvae. Larvae fed different feeds were analyzed for their nutrient compositions (i.e., such as proximate composition, minerals, amino acids, and heavy metals). Larvae fed 5% and 10% sprouted barley had maximum weight increases of 19.2% and 23.1%, respectively. Both treatment groups had significantly shorter larval periods than those of the control group. Sprouted barley markedly inhibited the growth of entomopathogenic S. marcescens. Furthermore, larvae fed sprouted barley exhibited higher Cu, Zn, and K levels. Seventeen amino acids were present in larvae fed sprouted barley, of which, tyrosine and glutamic acid were predominant. No heavy metals were detected in any of the investigated groups. Therefore, sprouted barley may be a suitable feed additive for producing high-quality P. brevitarsis larvae.

• Journal of Food Hygiene and Safety
• /
• v.36 no.3
• /
• pp.239-247
• /
• 2021

In order to confirm the impact of the Positive List System (PLS) being applied to all agricultural products from January 1, 2019, we analyzed 28,693 points of inspection-related data on agricultural products distributed in Gyeonggi-do from 2018 to 2020. The ratio of cases exceeding the standard for the total inspection performance was 1.0% in 2018, 1.2% in 2019, and 1.2% in 2020. Out of the 114 cases exceeding the standard in 2019, 55 were applied on a Maximum Residue Limit (MRL) of 0.01 mg/kg, and out of the 115 cases exceeding the standard in 2020, 66 were applied on a MRL of 0.01 mg/kg. To improve this, it seems necessary to manage unintentional pollution, conventional use for unregistered crops, and illegal pesticides. Fluquinconazole detection resulted from unintentional contamination, and diazinon, chlorothalonil, and methabenzthiazuron detection resulted from conventional use in unregistered crops. Chinomethionat is a pesticide component that was discarded in the past and its current use has been attributed to the smuggling of pesticides. This study and future monitoring data can be used as reference data for system supplementation and on-site management reinforcement.

• Journal of Mushroom
• /
• v.18 no.4
• /
• pp.357-364
• /
• 2020

The grade and price of Lentinula edodes largely differs in preference depending on the product area and seasonal factors. The product amount of autumn L. edodes was higher than that of spring L. edodes, but high quality, which is divided into "Hwago" is low in preference. Mostly, the autumn L. edodes is obtained as powder; hence, it is necessary to develop a processing method to utilize its flavor and aroma at an affordable price. Additionally, we estimated the content of 𝛽-glucan, ergosterol, vitamin D₂, reducing sugars, and free amino acids and evaluated the anti-inflammatory activity of saccharification powder of log-cultivated L. edodes. In the saccharification powders obtained via 7 min of UV irradiation of log-cultivated L. edodes, 𝛽-glucan and vitamin D₂ contents were found to be the highest, whereas ergosterol content was found to be the lowest. The content of reducing sugars ranged from 62.4 mg/L to 68.2 mg/L. The free amino acids were higher in these saccharification powders than in the control. Subsequently, RAW 264.7 cells were treated with different concentrations (10, 50, 100, 200, 300, and 500 ㎍/mL) of the saccharification powders of log-cultivated L. edodes obtained via different UV irradiation time applications. The cells showed good viability; the anti-inflammatory effect was found to be the highest at 7 min UV irradiation. Therefore, 7 min of UV irradiation was determined to be the optimum condition for manufacturing saccharification powders of log-cultivated L. edodes. Hence, saccharification powders of log-cultivated L. edodes may be used as a raw material for natural sweeteners, food additives, and in the food industry.

• Journal of fish pathology
• /
• v.33 no.2
• /
• pp.111-118
• /
• 2020

The genus Edwardsiella belonging to the family Enterobacteriaceae is a member of Gram-negative rod-shaped bacteria that cause disease in diverse aquatic organisms such as fish, amphibians and reptiles as well as avians and mammals including human throughout the world. This genus had been composed of three species, E. hoshinae, E. ictaluri and E. tarda, but recent researches erected two novel species, E. anguillarum and E. piscicida that were conventionally identified as E. tarda. In this study, we isolated seven strains belonging to the genus Edwardsiella from freshwater fishes that had been reared at inland fish farms in South Korea and investigated their biochemical characteristics and molecular phylogenetic relationships. The seven strains showed typical characteristics of four Edwardsiella species, E. anguillarum, E. ictaluri, E. piscicida and E. tarda, by biochemical analyses of Gram staining, indole and hydrogen sulfide (H2S) production, and API (Analytic Profile Index) 20E test. Molecular phylogenetic analyses inferred from DNA sequence data of both 16S ribosomal RNA (rRNA) and DNA gyrase subunit B (gyrB) genes were congruent with the biochemical characteristics. As a result, both biochemical and molecular phylogenetic analyses identified four strains isolated from three Anguilla species as E. anguillarum, E. piscicida and E. tarda, two strains from Pelteobagrus fulvidraco and Silurus asotus as E. ictaluri, and one strain from Moroco oxycephalus as E. piscicida. In this study, we isolated and successfully identified recently newly erected species, E. anguillarum and E. piscicida in addition to historically notorious pathogenic species, E. ictaluri and E. tarda. In the future study, systematic and comprehensive monitoring of the four Edwardsiella species are required for studying differences in pathogenicity among freshwater fishes.