• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.25-32
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• 1993

Granular activated carbon is commonly used in fixed-bed adsorbers to remove organic chemicals. In this experiment organic chemical solutions were prepared by adding the reagent grade organic chemical to distilled water. Isotherm adsorption tests of volatile organic chemicals were conducted using bottle-point technique and column test. Organic chemicals after passing through the column were extracted with hexane and analyzed with gas chromatography (Hewlett-Packard 5890) to check the adsorption capacity and breakthrough curve. The result were as follows: 1. The BET surface area of coconut activated carbon was 658~1,010 m$^2$/g where as coconut shell carbon was 6.6 m$^2$/g. Coconut activated carbon increased the BET surface area and adsorption capacity in bottle-point isotherm. 2. The adsorption capacity of coconut activated carbon for trichloroethylene (TCE) was reduced in the presence of humic substance. 3. A decrease in particle size of activated carbon resulted in higher adsorption capacity and lower intraparticle diffusion coefficient. It is reflected not only as a decrease in Freudlich adsorption capacity value (K) but also as an increase in Freudlich exponenent value (1/n).

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.59-62
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• 2001

The dried fruit-body of Daedaleopsis tricolor was extracted by the petroleum ether. The extracts were purified by liquid-liquid extraction, column chromatography, and recrystallization. The purified compound was a colorless orthorhombic crystal form. Its melting point, molecular weight and molar extinction coefficient $(\varepsilon)$ were estimated $168-170^{\circ}C$, 424 and 3,935 at 208 nm, respectively. Its structure was elucidated to be 20(29)-lupen-3-one by UV-Vis, FT-IR, NMR and X-ray crystallographic analysis. It showed antifungal activities against Saccharomyces cerevisiae and Microsporum gypseum, and antibacterial activities against Escherichia coli, Proteus vulgaris, Pseudomonas pyocyanea, Bacillus subtilis, and Staphylococcus aureus. In addition, this compound showed an antioxidative activity on lipid-peroxidation by 6.4%.

• Environmental Analysis Health and Toxicology
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• v.30
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• pp.17.1-17.6
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• 2015

Objectives In this study, the possibility of using existing test data provided in Korea and elsewhere for the registration of chemical substances was examined. Data on 510 chemical substances that are among the first subject to registration under the "Act on the Registration and Evaluation, etc. of Chemical Substances (K-REACH)" were analyzed. Methods The possibility of using existing data from 16 reference databases was examined for 510 chemical substances notified in July 2015 as being subject to registration. Results Test data with the reliability required for the registration of chemical substances under the K-REACH constituted 48.4% of the required physicochemical characteristics, 6.5% of the required health hazards, and 9.4% of the required environmental hazards. Conclusions Some existing test data were not within the scope of this research, including data used for registration in the European Union (EU). Thus, considering that 350 of these 510 species are registered in EU Registration, Evaluation, Authorisation & Restriction of Chemicals, more test data may exist that can be utilized in addition to the data identified in this study. Furthermore, the K-REACH states that non-testing data (test results predicted through Read Across, Quantitative Structure-Activity Relationships) and the weight of evidence (test results predicted based on test data with low reliability) can also be utilized for registration data. Therefore, if methods for using such data were actively reviewed, it would be possible to reduce the cost of securing test data required for the registration of chemical substances.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.57-63
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• 2017

Foreign materials with a variety of types and sizes are found in food; thus, extraordinary efforts and various analytical methods are required to identify the types of foreign materials and to find out accurate causes of how they unintentionally enter food. In this study, human, cow, pig, mouse, duck, goose, dog, and cat were chosen as various types of animal hairs because they can be frequently incorporated into food during its production or consumption step. We morphologically analyzed them using stereoscopic, optical, SUMP method, and scanning electron microscopes, showing differences in each type. In addition, X-ray fluorescence spectrometer (XRF) was used to analysis chemical compositions ($^{11}Na{\sim}^{92}U$, Mass%) of samples. As a result, we observed that mammalian hairs were mainly composed of sulfur. Organic compounds of samples were further analyzed by fourier transform infrared spectroscopy (FT-IR) that can compare spectra of given materials; however, this method did not show significant differences in each sample. In this study, we suggest a rapid method for the identification of the causes and types of foreign materials in food.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.2
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• pp.73-81
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• 2011

The purpose of this study was to obtain scientific information regarding classification and health hazards that may result from a 13 weeks inhalation exposure of isoprene in Sprague-Dawley (SD) rats. The testing method was conducted in accordance with OECD guidelines for the testing of chemicals No. 413. The Rats were divided into 4 groups (10 male and 10 female rats in each group) and exposed to 0, 360, 1,620, 7,300 ppm isoprene in each exposure chamber for 6 h/day, 5 days/week, for 13 weeks. As a result, there were no mortality or abnormality during the period of study and did not show any significant changes of body weight. There were no dose response changes in urinalysis, hematological and serum biochemical value examination. Relative organ weight was increased significantly the right kidney in 7,300 ppm group of male rats. In female rats, relative organ weight of the left kidney and the both lungs in 1,620 ppm group and the left lung and the both kidneys in 7,300 ppm group were increased significantly. But the histopathological findings did not reveal any exposure-related changes. According to the above results, the no observable adverse effect level (NOAEL) of isoprene was 7,300 ppm (20.3 mg/L) in both male and female rats. In conclusion, Isoprene was not classified specific target organ toxicity of the 'Standard for Classification and Labeling of Chemical Substance and Material Safety Data Sheet' (Ministry of Employment and Labor, 2009).

• Journal of the Korean Wood Science and Technology
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• v.49 no.5
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• pp.416-429
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• 2021

Raru is a lesser-known plant species originating from North Sumatra, Indonesia. Information on the characteristics is still limited, especially its chemical component. Therefore, this study aims to examine the chemical composition information of Cotylelobium lanceolatum, Cotylelobium melanoxylon, and Vatica pauciflora woods based on their axial log positions (bottom, middle, and top). The wood chemical analysis was performed in terms of the Indonesian National Standard (SNI) method. Furthermore, the analysis measured holocellulose, 𝛼-cellulose, hemicellulose, lignin content, alcohol benzene extractive content, the extractive substance in hot and water, and solubility in NaOH 1%. The results indicated that the species and their log axial positions affected different chemical components, which included 𝛼-cellulose, hemicellulose, and lignin of C. lanceolatum amounting to 41.88%, 19.39%, and 28.68% respectively. Meanwhile, for C. Melanoxylon, they were 42.01%, 21.11%, and 24.76% respectively; and for V. pauciflora wood, they were 42.95%, 23.24%, and 30.11% respectively. The average values of the extractive contents including the solubility in 1: 2 ethanol benzene, NaOH, and hot water for C. lanceolatum, C. melanoxylon, and V. pauciflora wood were (10.58%, 27.62%, 8.13%), (14.54%, 28.22%, 7.82%), and (10.95%, 28.60%, 7.57%) respectively. The wood species had a significant effect on chemical components including lignin, cellulose and hemicellulose, and extractive solubility in cold water. Furthermore, the axial log position had a significant effect on all the parameters of the chemical composition of the wood being tested.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.3
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• pp.265-272
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• 2023

Objectives: Since the material safety data sheets(MSDS) submission and non-disclosure review system was introduced in January 2021, the implementation status of MSDS for chemical manufacturing and importing workplaces being supervised for the first time. Methods: A supervisory team consisting of two labor inspectors and one from the Korea Occupational Safety and Health Agency directly visited the selected workplaces to check compliance with the MSDS system as a whole. Results: As a result of supervising 214 chemical substance manufacturing/importing workplaces, a total of 241 violations of the law were found in 121 workplaces, or 57% of them. In response, the Ministry of Employment and Labor took legal action on 8 cases in 6 locations, imposed a fines totaling of 249.69 million won on 120 chemical handling workplaces, and took action to correct the violations immediately. Conclusions: Major violations were in the order of non-request for warning signs, non-submission of MSDS, non-execution of MSDS training, and non-posting of MSDS. This shows the reality that employers who handle chemical substances are sufficiently communicating chemical information to workers. In the future, the government will actively implement preparation and submission support and system guidance for the implementation of the MSDS system, while making efforts to ensure that the MSDS system works well in the field through thorough on-site supervision in the future.

• Industry Promotion Research
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• v.9 no.1
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• pp.57-64
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• 2024

In 2015, the paradigm of hazardous chemical substance management in Korea shifted from the workplace to the regional level due to the complete revision of the Chemicals Control Act. Although regional chemical accident response plans were established in 2020, there were slight differences in the scope and criteria of each local government. Therefore, this study compared and analyzed chemical accident response plans established in four different regions to provide insights into effective chemical accident response plans. Based on publicly available information, the current status of accident preparedness, chemical accident response systems, and resident evacuation response and education/training were compared and analyzed. The results showed that there were not significant differences in the accident preparedness and response systems between the regions. However, there was a lack of discussion on the preparedness system linked to the characteristics of each workplace in each region. Additionally, there were differences in education and training for residents between regions. In the future, each local government needs to establish a response organization that fits the characteristics of their region and develop strategies for agile and effective accident response through cooperation with relevant agencies.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.571-578
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• 2016

Recently, review on viability of various industrial by product and natural materials as raw material for concrete has been actively done in aspect of environment-friendly issue and depletion of natural resource. This study conducted fundamental study on the possibility of utilizing mud flat as admixture and filling material for concrete. First, chemical analysis on the viability of mud flat as admixture was done and the researchers compared it with the substance of fly ash and blast furnace slag. According to the result, substance content was proven to be inadequate. In addition, as the replacement rate of mud flat increased, compressive strength and tensile strength decreased. According to the estimated result of chemical substance analysis, possibility of utilizing mud flat as admixture was low. According to the result of experiment done as filling material, 10% ~ 30% replacement rate of mud flat manifested more than 8 Mpa of compressive strength of block which may be utilized for secondary product. However, additional experiment such as making block is required afterward. According to the result of flow experiment, as the replacement rate of mud flat increased, flow value decreased, and through chloride content analysis test, it was proven that mud flat is inappropriate to be applied as steel beam using structure since it has high content of sodium. It may be utilized as products that does not use steel beam such as internal brick.

• Journal of IKEEE
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• v.22 no.4
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• pp.1062-1067
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• 2018

In this study, the research processed with a chemical sensor for measuring trace amount of heavy metal ions which is based on the requirements of the efficient sensing technology as recent equipment is applies molecular system in the chemical sensing section that can precisely recognizing selective target substance and transmit its data to physical signal as a result. In this research is concentrated on realize highly precise by utilizing SPR sensor application of recognition functional sensing membrane. Consequently, according to DTSQ-dye sensing membrane, the resonance angle from low-concentration to the highest concentration $10^{-4}M$ of $Ag^+$ ion is $2.17[^{\circ}]$ and this result indicating 4.3 times larger resonance angle changes compare to the other metal substance. Based on SQ-dye sensing membrane, the difference of resonance angle between low concentration and the highest concentration $10^{-4}M$ of $Cu^{2+}$ ion is $2.3[^{\circ}]$ and this outcome is indicating 4.5 times greater resonance angle change to the other metal substance.