• Journal of the Korean Institute of Gas
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• v.21 no.1
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• pp.6-17
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• 2017

Objectives : The purpose of this study was to obtain information regarding Globally Harmonized System(GHS) classification and health hazards that may result from a 4 weeks inhalation exposure of 3-Methylpentane in Sprague-Dawley rats. Methods : The testing method was conducted in accordance with OECD guidelines for the testing of chemicals No. 412(Subacute Inhalation Toxicity). The Rats were divided into 4 groups(5 male and 5 female rats in each group) and exposed to 0 ppm, 284 ppm, 1,135 ppm, 4,540 ppm 3-Methylpentane in each exposure chamber for 6 h/day, 5 days/week, for 4 weeks. After two weeks, the test animals were autopsied and carried out blood test and biochemical tests and histopathological examination. We used PRISTIMA (Toxicology data management system) to confirm the system and to have confidence of the raw data. Results : No death and particular clinical presentation including weight change and change of feed rate was observed. Relationship between dose, gender and response was also not significantly changed in hematologic examination, biochemical examination of blood and blood coagulation time. The histopathologic lesions caused by the test substance did not appear. Conclusions : NOAEL(No Observable Adverse Effect Level) of 3-Methylpentane is more than 4,540 ppm in male group and female group and the Ministry of Employment and Labor Guidance Announcement No. 2013-37(criteria for the classification marks and Safety of Chemicals) Specific target organ toxicity(repeated exposure) was determined with a substance that is not the separator material.

• Journal of the Korean Institute of Gas
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• v.24 no.4
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• pp.84-92
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• 2020

Most facilities in chemical plants operate in environments that are outside the range of temperature and pressure that can be encountered on a daily basis, and are vulnerable to aging due to these stresses and environmental conditions. The facilities exposed to these conditions are not only likely to fail due to cumulative damage, but also lead to accidents if maintenance and replacement are not performed.Recommendation guidelines called risk-based inspection are widely used around the world-wide. However, limits exist for facilities that have already elapsed for a certain. As a result of the survey on the aging of Ulsan industrial complex in Korea, which carries out proper inspection, many of the facilities have been used for 20 years. Also, most of the facilities where the accident occurred have been in operation for more than 20 years. Therefore, this study suggested criteria for classifying devices that have exceeded a certain period of use as obsolete facilities. In addition, quantitative risk assessment was conducted. The safety investment method using the cost-benefit analysis method was proposed in order to calculate the loss cost and reduce the risk by expressing the risks of the corresponding aged facility as an Economic index. By utilizing the method of cost-benefit analysis of old facilities using the quantitative risk assessment presented in this study, it can be expected to improve the performance and life of old facilities, improve production efficiency and reliability of the system of facilities, change the recognition of safety management costs, increase employee stability, and reduce loss costs.

• Resources Recycling
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• v.6 no.2
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• pp.22-28
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• 1997

In recent yean thc problem of wastc plastics arc greatly incrcascd with ihe result uf lndushial growth. As a rcsult the amount of wastc plaslics in domestic area is appraxhnately 2,300,000 t<~nin 1996 base and contmuously increasing more than 12% cvcry ycar. Thc disposal way of these waste plastics arc dlLl malnly rely~ng on landill1 or partially incinuralion So that it hss become a senous social problem due to the second envirnmentd pollution. The tcchnologics iar prducing oil from the waste plastics have hccn dcvelopcd far along pennd and currently some of them are in a commercialiration stage Pyrolysis process in one of the major process m heating waslc plaslics bul still has some restlichons for the cammcrc~dizatian duc lo 11s emnom~cal problems assaciated with a systcmiltlc lecd collcctionidispnsJ ways. Cansldenng cnvaomcnld problems, thc inclease m the charge for waste matcds trcatmcnt and thc lmlitarion ni disposal area, it is inteicstcd that the wastc plastics treabncnt by pyrolysn. which would be the safest and the most eilic~ent process for cnnvcrting fecd wastc to rc-usablc rcsourccs. would he predomhant m ihe near h~lurc Thc shldy aims inr the development of haslc ted~nolagy for scaling up to a com~nercial sire through pyrolys~s process which is cnnduclcd under the absence of air. Furthern~orc the waste plastics can be recycled as iual gas or oil wilhout harmful effects in enviroment, The waste w e d plastics arc pyrolyzed in (he fluidized bcd rcaclor under continuous way and thc ail ylcld gives approx~marcly 47 4%.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.520-520
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• 2016

석유 화학공장에서 발생하는 spent sulfidic caustic (SSC) 폐수는 액화석유가스(LPG)나 천연가스(NG)의 정제과정에서 발생되는 것으로 고농도의 sulfide와 cresylic, phenolic 그리고 mercaptan 등이 포함된 독성과 냄새를 유발하는 물질이다. 이러한 물질들은 LPG나 NG의 정제과정에서 높은 산도를 가진 휘발성 황화합 물질들을 제거하기 위해 사용된 NaOH가 $H_2S$와 반응하여 발생하는 것이다. 진한 갈색 또는 검은색을 띄는 SSC 폐수는 12 이상의 높은 pH를 가지고 있으며 5~12 wt%의 높은 염분도를 가지고 있다. 또한 강한 부식성과 독성을 가진 황화합물의 농도가 1~4 wt%이며, 방향족 탄화수소 물질 (i.e. methanethiol, benzene, tolune and phenol)들도 다량 함유되어 있다. 따라서 이러한 유해 물질들은 기존의 하수처리 공정으로 방류하기 전에 완벽하게 처리해야만 하수처리 공정의 오염 부하량을 줄일 수 있다. 습식산화공정은 SSC 폐수를 처리하기 위해 흔히 사용되고 있는 물리-화학적 처리 공정이지만 고비용, 고에너지가 필요하며, 고온 및 고압에서만 작동되어 안전상의 문제점을 갖고 있다. 또한 습식산화공정을 거친 폐수는 배출허용기준을 만족하기 위해 생물학적 2차 처리가 반드시 필요하다. 철-과산화수소를 이용하는 펜톤산화 공정, 그리고 sulfide를 sulfate로 전환시키는 생물학적 처리 공정은 황화합물의 완전한 무기물화가 힘들며, 현장 적용 시 기술적 경제적 부담이 크다. 이러한 단점을 극복하고, SSC 폐수를 효과적으로 처리하기 위해 본 연구는, 높은 흡착력과 광산화력을 가진 흡착광산화 반응 시스템(Adsorption Photocatalysis System, APS)을 개발하였다. APS는 SSC 폐수를 시스템 내부로 유입하여 수중의 오염물질을 흡착광산화제로 구성된 반응구조체가 흡착하고, 흡착된 오염물질을 UV에너지와 이산화티타늄 광촉매의 광화학반응에 의해 최종적으로 무해한 물질로 환원시키는 폐수처리시스템이다. APS의 반응구조체는 태양에너지 및 인공에너지원에 의해 활용 가능하며, 난분해성 유기화합물질을 물과 이산화탄소로 분해할 수 있는 친환경적이고 경제적인 소재로서 널리 쓰이고 있는 이산화티타늄 광촉매와 화력발전소의 높은 소성온도에 의해 연소된 후 발생되는 bottom ash를 이산화티타늄의 지지체로 사용하여 높은 흡착력과 광촉매 산화력을 가진 복합물이다. 개발된 APS에 의해 SSC 폐수를 처리한 결과, COD 86.1%, 탁도 98.4%, sulfide 99.9%의 높은 처리효율을 보여주고 있다. 따라서 본 연구를 통해 개발된 APS는 강한 부식성과 독성 그리고 높은 농도를 가지고 있는 SSC 폐수를 효과적으로 처리할 수 있다.

• Journal of the Korean Applied Science and Technology
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• v.38 no.5
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• pp.1241-1248
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• 2021

In order to figure out various environmental problems, various governments and companies are investigating more environmentally policies and technologies. In other words, activated carbon is widely used for the adsorption of different harmful gases and waste liquid treatment. However since the required surface properties are different in various industry, depending on the adsorption properties, the development of activated carbon demand in different ways. In this work, we have investigated and developed the activated carbon surface to improve the hydrophilic properties by nitric acid treatment through reforming of activated carbon.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.136-143
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• 2018

Cellular automata have been applied to simulations in many fields such as astrophysics, social phenomena, fire spread, and evacuation. Using cellular automata, this study develops a model for consequence analysis of the dispersion of hazardous chemicals, which is required for risk assessments of and emergency responses for frequent chemical accidents. Unlike in cases of detailed plant safety design, real-time accident responses require fast and iterative calculations to reduce the uncertainty of the distribution of damage within the affected area. EPA ALOHA and KORA of National Institute of Chemical Safety have been popular choices for these analyses. However, this study proposes an initiative to supplement the model and code continuously and is different in its development of free software, specialized for small and medium enterprises. Compared to the full-scale computational fluid dynamics (CFD), which requires large amounts of computation time, the relative accuracy loss is compromised, and the convenience of the general user is improved. Using Python open-source libraries as well as meteorological information linkage, it is made possible to expand and update the functions continuously. Users can easily obtain the results by simply inputting the layout of the plant and the materials used. Accuracy is verified against full-scale CFD simulations, and it will be distributed as open source software, supporting GPU-accelerated computing for fast computation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.3
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• pp.132-139
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• 2019

EPS (expanded polystyrene) is one of the most used building materials for insulation that is favored by its excellent heat insulation, economical efficiency and lightweight characteristics. However, EPS is vulnerable to the fire and producing large amount of toxic gases in case of fire. Therefore, ultra-lightweight geopolymer which can replace EPS is fabricated by using IGCC (integrated gasification combined cycle) fused slag and Si sludge as raw materials and the possibility of replacement on ultra-lightweight geopolymer for EPS as an insulation building material was evaluated in this study. Ultra-lightweight geopolymer can be fabricated with the pulverized IGCC fused slag having low carbon content and density, compressive strength, thermal conductivity were $0.064g/cm^3$, 0.04 MPa, and 0.072 W/mK, respectively. The thermal conductivity of ultra-lightweight geopolymer is 1.5~2.0 times higher than that of EPS suggested in the KS M 3808; however, the thermal conductivity value of geopolymer is meaningful and competitive to that of EPS in the market. Therefore, ultralightweight geopolymer can be applicable to the building material for thermal insulation purpose and have an enough possibility to replace EPS in the future because it is not only much safer than EPS in case of fire but also it can be fabricate by using waste materials from the industry.

• Journal of the Korean Chemical Society
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• v.64 no.6
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• pp.327-333
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• 2020

Performance of a portable GC that can be utilized for the real time determination of volatile organic compounds in air was evaluated. It employs purified/compressed ambient air as the carrier gas eliminating the need for high pressure gas tanks. The compact system with dimensions of 35 × 26 × 15 ㎤ and weight of 5 kg is powered by either a 24 V DC external adapter or battery pack. Chromatograms of the mixture sample including benzene, toluene, ethylbenzene, and oxylene at concentrations of 1 ppmv and 20 ppmv represent a good reproducibility: 3.79% and 0.48% relative standard deviations (RSDs) for peak area variations; 0.40% and 0.08% RSDs for retention times. The method detection limit was 0.09 ppmv. A 30 m long, 0.28 mm I.D. column operated at an optimal condition yielded a peak capacity of 61 with good resolution for a 10 min isothermal analysis. The relative standard deviations (RSD) of the peak area variations and retention times during consecutive measurements over 27 h were less than 2.4%RSD and 0.5%RSD, respectively. Thus, this instrument makes it suitable for continuous and field analysis of low-concentration VOC mixtures in the indoor/outdoor environment as well as the spillage accident of hazardous chemicals.

• Journal of the Korea Institute of Building Construction
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• v.23 no.5
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• pp.537-546
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• 2023

For the purpose of fire delineation within buildings, steel walls in Korea are mandated to undergo rigorous certification as fire-resistant entities, substantiated via a series of qualitative assessments. Predominantly, these evaluations comprise the fire resistance test paired with supplementary examinations; specifically for steel walls, these encompass the gas hazard and panel bending strength tests. Given the prevalence of semi-noncombustible core materials, gas hazard tests are largely rendered superfluous, pivoting the focus solely onto the panel bending strength test during the certification trajectory. This particular test is designed to gauge the flexural robustness of individual wall panels. An enhanced bending strength is postulated to fortify both the structural integrity and thermal insulation of the wall by mitigating potential deformations. In this scholarly exploration, an analytical deep dive was undertaken into extant, valid certification test datasets. The endeavor aimed to ascertain the depth of correlation between the designated fire resistance metric and the bending strength, the latter being the sole supplementary assessment for steel walls. In distilling the findings, it was discerned that temperature elevations beyond baseline values exhibited no statistically salient linkage with the panel's bending strength.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.327-332
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• 2008

This study was conducted to evaluate the effects of dietary Bacillus subtilis on meat quality, growth performance and fecal malodor gas emission in finishing pigs. Thirty-six pigs (Landrace ${\times}$ Yorkshire ${\times}$ Duroc, $83.53{\pm}1.01\;kg$ average initial body weight) were used in a 35 d growth assay. Dietary treatments were 1) CON (basal diet), 2) B1 (basal diet + B. subtilis 0.1%) and 3) B2 (basal diet + B. subtilis 0.2%). The pigs were distributed into four pigs per pen with three replicate pens per treatments by completely randomized design. For the entire period, the final weight, ADO, ADFI and gain/feed were not significantly different among the treatments. There were no significant differences in meat quality (sensory evalution, meat color, TBARS, water holding capacity, drip loss, cooking loss and M. longissimus dorsi area) among the treatments. $H_2S$ was significantly decreased in B2 treatment compared to CON and B1 treatments (p<0.05). However, ammonia, mercaptans and acetic acid were not significantly different among the treatments. In conclusion, B. subtilis 0.2% treatments decreased fecal $H_2S$ gas emission in finishing pigs.