• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.1-8
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• 2016

Gu-mi hydrogen fluoride leak accident in 2012 was amplified social anxiety for chemical accidents. To relieve these anxieties Off-site Risk Assessment was introduced in 2015. Off-site Risk Assessment is targeted at most chemicals, and most of the high-pressure-toxic gases which are mainly used in high-tech industries such as semi conductor, display, Photovoltaic panels industry are included in the substance of the Off-site Risk Assessment. Since Korean companies occupy a high market share in high-tech industries, high pressure-toxic domestic gas consumption is constantly increasing. Accordingly, it is expected to increase the possibility of accidents. In accordance with the circumstances, this study was to conducted Consequence Analysis(CA) about high pressure-toxic gases those are high demand in domestic. CA was used for ALOHA developed by US EPA & US NOAA and the CA result of Arsine was the largest at 4,700 m. CA results are expected to be utilized for determining the effective Safety distances when high pressure-toxic gas leak.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.224-236
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• 2015

We conducted the algicidal activity screening tests using 10 L microcosm to investigate the possibility of the field application of naphthoquinone derivative Nq 4-6 compound as an algicide. We determined its application range to assess its algicidal effects on the phytoplankton and to evaluate the response of the planktonic community and the water environment to this chemical. From results of the microcosm experiments, Nq 4-6 compound showed high algicidal activity on the centric diatoms such as Stephanodiscus hantzschii and Cyclotella meneghiniana, but it had no effect on other phytoplankton. The abundance of S. hantzschii continuously increased in the control, but its cell density decreased 1 day after the Nq 4-6 treatment. In particular, Nq 4-6 showed algicidal activity of 94.4% against S. hantzschii 7 days after the treatment. The dominance index of phytoplankton community was lower in the treatment than in the control. The diversity index, richness index and evenness index of phytoplankton community was higher in the treatment. Environmental factors and biological factors did not show specific changes after the Nq 4-6 compound treatment. Therefore, the results of this study demonstrates that Nq 4-6 is an effective agent for the control of S. hantzschii blooms, and that the microcosm tests play a crucial role when assessing field application.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.202-206
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• 2013

Biocontrol potential of an isolate of Helicosporium spp. against Rhizoctonia solani, Fusarium oxysporium and Phytophthora drechsleri was evaluated in vitro and in vivo. A selected biocontrol agent designated as Helicosporium 0635BP strongly inhibited growth and lysed mycelium of Rhizoctonia solani and Fusarium oxysporium on PDA. Autoclaved culture filtrate of the agent also completely inhibited growth of the turfgrass large patch pathogen, R. solani AG2-2 IV at the concentration of 50 ml $L^{-1}$. The pathogen was killed when dipped under the 20% filtrate for four hours or 50% for one hr. In a field trial, plots applied with the crude or times diluted culture filtrate showed 100% control efficacy of the turfgrass large patch as a chemical applied for a comparison. Results indicated that Helicosporium 0635BP is a promising biocontrol agent on control of the turfgrass large patch disease and its culture filtrate contained unknown heat suitable antifungal substance (s). Further studies on mass production, purification and identification of the unknown compound (s) are in progress for practical use.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.147-154
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• 2010

Gulbi, made of fresh yellow corvenia (Psendosciaena manchurica) that has been salted and dried, is one of the most popular traditional marine foods in Korea. The objective of this study was to develop a method to safely manufacture Gulbi with low levels of oxidation and contamination, by a hot air drying method. Changes in total acidity, pH, salt concentration, thiobarbituric acid-reactive substance (TBARS) and volatile basic nitrogen (VBN) were measured during drying at 30, 35 and $40^{\circ}C$ for 15 days in a hot air-dryer using a semi-dried method. Acidity increased with increasing drying time at all drying temperatures. The pH decreased gradually with increasing drying time. Salt concentration was increased as drying time increased at all drying temperatures due to moisture loss. The VBN increased as drying time increased for all drying temperatures. Data indicate that the drying at $35^{\circ}C$ appears to have a significant sensory and physicochemical advantage in Gulbi products.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.355-359
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• 2017

We investigated and compared certain chemical properties of Korean natural honey and sugar-fed honey for assessing quality characteristics. The specification component was extracted using an organic solvent, and a single substance was isolated and identified as (E)-2-decenedioic acid. The content of (E)-2-decenedioic acid was $121{\pm}5.9mg/100g$ in sugar cane-fed honey and $127{\pm}4.5mg/100g$ in sugar beet-fed honey. Natural acacia, chestnut, and multi-floral honey contain $13{\pm}0.9$, $17{\pm}0.6$, and $13{\pm}1.3mg/100g$ of honey, respectively. Therefore, (E)-2-decenedioic acid was a major component of sugar-fed honey, however, it occurred in trace amounts in natural honey. We conclude that natural and sugar-fed honey can be distinguished by determining the (E)-2-decenedioic acid content.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.111-122
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• 2021

Objectives: There was a judgment of acquittal for the manufacturer SK Chemical and the vendor Aekyung regarding humidifier disinfectant (HD) containing 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT). The rationale used in this judgement is discussed here in the light of scientific consideration. Methods: The sentencing document for the judgements was obtained from the Korea Supreme Court Service. In particular, the judgements made by the court related to the risk of HD and external and internal exposure to CMIT/MIT are discussed based on scientific evidence. Results: Rendering a determination in a criminal trial of insufficient evidence of causation, the court dismissed the prosecution's motion that humidifier disinfectant-associated lung injuries (HDLI) and asthma were associated with the utilization of these products. However, CMIT/MIT, a strong sensitizing and corrosive substance, has been reported to be associated with brain toxicity, allergic contact dermatitis, and asthma. Furthermore, the judgment did not consider total consumption amounts or the cumulative dose of CMIT/MIT in the humidifier. Lastly, there are several cases supporting the fact that exposure to water-soluble substances including CMIT/MIT can cause lower respiratory tract diseases. In addition to cases of asthma among the workers exposed to CMIT/MIT, we identified lung injury victims who were exposed to HDs exclusively containing CMIT/MIT. Conclusions: We conclude that there is sufficient evidence supporting the assertion that HDs containing CMIT/MIT cause lung injuries, including asthma, contrary to the court's judgement.

• Journal of Ginseng Culture
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• v.1
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• pp.57-66
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• 2019

Ginseng has been recognized as a lifespan extending medicine which has been regarded as one of the medicines classified as top medicines, as the Boncho (medical herbs) study which is influenced by the idea of guidance's costume and food concept mainly in China is gaining its bona fide form. As the demand for ginseng has been expanded to other levels, the demand for ginseng has been increasing. Ginseng from the nature reached its supply chain limit due to its extinction and difficulty of picking, so it translated into ginseng cultivation of economy rather than harvesting in nature. After the start of ginseng cultivation, the ginseng cultivation was further enhanced by the rapid development of processing methods such as white-ginseng and red-ginseng, and the surge of consumption due to the traditional belief in ginseng drug efficacy and support of scientific research. In the Joseon Dynasty, the name Gasam (cultivated ginseng) had been created as ginseng was cultivated on farmland after the stage of SanYang (wild cultivated ginseng), the purpose of the new name Gasam is to differentiate from natural ginseng, and natural ginseng lost its firm position as the genuine ginseng as the Gasam replaced the genuine ginseng, and the natural ginseng got a new name of SanSam (wild ginseng). Because the real ginseng substance concept dissipated, and as Gasam is being called ginseng, the name Gasam was also disappeared. As a result, it was possible to grow large quantities according to the arrival of the Gasam era, and it was possible to supply the demand for ginseng, and it could become one agricultural industry. In this ginseng cultivation, in Japan where ginseng did not grow naturally, it was difficult to obtain ginseng from Joseon and faced with a shortage of ginseng at all times. Therefore, the shogun cultivated the Gasam systematically at the national level by the inside of the shogunate. However, since the natural ginseng is native to China and Korea, there is a concern about the deterioration of the quality of natural ginseng due to the incorporation of cultivated ginseng (Gasam). To protect the interests, the cultivation of ginseng was subject to control. For this reason, the lack of historical information on Gasam cultivation, which had to be started secretly, would be a natural result. In this paper, althouh not sufficient enough, the historical informations were used to summarize the history of ginseng cultivation in China, Japan and Korea.

• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.285-294
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• 2019

Objectives: For suitable risk management of the domestic aquatic environment, it is necessary to conduct toxicity tests using species native to Korea. In the present study, we performed toxicity ring tests using endemic freshwater arthropoda Neocaridina denticulata and evaluated its validity and reproducibility as an international standard test species. Methods: To evaluate the sensitivity levels of N. denticulata to hazardous chemicals, toxicity values for several chemicals were compared with other standard test species. Intra- and inter-laboratory acute toxicity tests were performed both within a single laboratory and among four laboratories respectively using 3,4-Dichloroaniline, which is generally used as a reference test substance in fish toxicity tests. In addition, intra- and inter-laboratory coefficient of variations (CVs) were calculated to evaluate reproducibility based on the estimated toxicity values. Results: The sensitivity of N. denticulata to several chemicals was found to be similar with D. manga, indicating that the species is valid as a test species. The CVs of the intra- and inter-laboratory tests were 22.946% with four qualified runs and 8.828% among the four laboratories, respectively. Conclusions: N. denticulata serves in an important role in the food chain of Korean aquatic ecosystems and also inhabits several other Asian countries. Since the validity and reproducibility of the species were confirmed as a toxicity test species in this study, further efforts are needed to establish N. denticulata as the international standard test species for the appropriate risk assessment of aquatic ecosystems at home and abroad.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.357-364
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• 2018

Fly ash is a material used as a concrete admixture. When fly ash is used for concrete manufacturing, it is expected to improve the performance such as reduction of cement usage and increase of chemical resistance. However, fly ash have some problems such as unburned carbon content and amorphous film on the surface of fly ash particles. When concrete is manufactured using fly ash containing a large amount of unburned carbon, there is a problem that the slump is lowered due to adsorption of AE agent. In addition, the amorphous film on the surface of the particles prevents the reactive substances from leaching out of the fly ash. Therefore, a method of surface treatment of fly ash using plasma has been studied to remove such unburned carbon and amorphous films. However, plasma has the problem that $O_3$ is generated when $O_2$ is used as an active gas. $O_3$ is a harmful substance and adversely affects the health of the experimenter. In this study, the surface of fly ash was treatment by arc discharge. Experimental results show that the unburned carbon is removed when the surface of fly ash is treatment by arc discharge and the amorphous film was broken and the reactivity was improved. Therefore, it is considered that arc discharge can treatment the surface of fly ash and improve the quality of fly ash.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.311-316
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• 2019

Japanese anise (Illicium anisatum L.) leaves and twigs were extracted with 50 % aqueous acetone three times. After filtration, the extracts were fractionated with n-hexane, chloroform, ethyl acetate and $H_2O$, and then freeze dried after condensation. Then antioxidation and antiviral activity were evaluated on each fractions. In the antioxidative activities, the results indicated high activity in the EtOAc soluble fraction of the leaves and the EtOAc and $H_2O$ soluble fractions of the twigs. It showed much higher antioxidative value compare to the controls, BHT and ${\alpha}$-tocopherol. In the antiviral activities, the all fractions were negative effects in HRV 1B and EV 71, but good in Influenza PR8. The activities of the crude extracts of the leaves and twigs showed more than 80% activity at the concentration of $10{\mu}g/mL$ and $50{\mu}g/mL$, respectively, and the activities of the EtOAc and $H_2O$ soluble fractions were close to 80%. Based on the above results, the extracts of Japanese anise may be applied for one of the natural biomass sources that can be used as an antioxidant and an antiviral substance.