• Title/Summary/Keyword: 탄소성 모델

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Study on the hepatoprotective effects of lemon balm and dandelion leaf extract combination in carbon tetrachloride-mediated liver injured mice (사염화탄소 유도성 급성 간 손상 모델에서 레몬밤과 민들레 잎 추출물의 혼합 비율에 따른 간 보호 효능 연구)

  • Choi, Beom-Rak;Cho, Il Je;Jung, Su-Jin;Kim, Jae Kwang;Lee, Dae Geon;Ku, Sae Kwang;Park, Ki-Moon
    • Herbal Formula Science
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    • v.27 no.3
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    • pp.199-211
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    • 2019
  • Objectives : Present study investigated the hepatoprotective effects of various combinations of lemon balm and dandelion (LD) leaf extract on carbon tetrachloride ($CCl_4$)-induced acute liver injury. Methods : Mice were orally treated with 200 mg/kg of LD extracts [1:1, 1:2, 1:4, 1:6, 1:8, 2:1, 4:1, 6:1, or 8:1 (weight : weight)] for 7 days, and then intraperitoneally injected with $CCl_4$ (0.5 mL/kg). Silymarin (100 mg/kg) was used as reference drug. Body weight gain, relative liver weight, serum biochemistry, histopathologic analyses, and hepatic antioxidant system were examined to elucidate the fittest combination ratio of LD extract. Results : All varying combinations of LD extract significantly increased body weight gain and decreased relative liver weight by $CCl_4$. In addition, LD extract reduced serum aspartate aminotransferase and alanine aminotransferase. Histopathological analyses indicated that LD extract significantly decreased histological activity index score, degenerated hepatocytes, and infiltrated inflammatory cells induced by $CCl_4$. Moreover, LD extract reduced lipid peroxidation, and attenuated the reduction of hepatic glutathione, superoxide dismutase, and catalase by $CCl_4$. Although there were no statistical differences in body weight gain between silymarin- and LD extract-treated groups, administration of 1:1, 2:1, and 4:1 combination of LD extract exhibited more favorable hepatoprotective effects than silymarin. Especially, 2:1 combination of LD extract showed the most potent hepatoprotective effects. Conclusion : Of various combinations of LD extract tested, present results suggest that 2:1 combination of LD extract would be a promising herbal formulation to protect liver from oxidative stress.

The Applicability of Metaverse for Urban Inundation Response (도시 침수 대응을 위한 메타버스의 활용 가능성 고찰)

  • Kim, Dong Hyun;Park, Hyung Jun;Yoo, Hyung Ju;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
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    • v.15 no.2
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    • pp.13-25
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    • 2022
  • Public consent is essential to proceed with large-scale projects such as dam and hydroelectric power plant in the Carbon Neutral Era. In general, when designing facilities such as dams and river facilities, the impact due to constructing them is analyzed through numerical simulation in advance. Those facilities are built to cope with floods and usually HEC-RAS is used for numerical simulation in this process. The numerical simulation provides accurate data, but it is very difficult to persuade the public only with the data. Therefore, this study intends to consider the utilization of metaverse in the field of urban flooding and flood response. The applicability of metaverse was confirmed by emphasizing visual effects and providing easy-to-see data, using a kind of metaverse platform called Cities: Skylines. The functions and limitations of this platform were reviewed. A virtual flood scenario was applied after implementing real cities on a metaverse. The hazard map established in Korea and the results of applying the scenario of metaverse platform were compared. On the metaverse, not only the disaster situation caused by realizing the city and society as it is, but also the spread of social disasters after the disaster can be confirmed. Through this, countermeasures can be virtually implemented. If these social and humanistic data are also verified in the future, it is expected that the overall process for responding to urban flooding can be modeled.

A Comparative Study on the Effect of Tamping Materials on the Impact Efficiency at Blasting Work (발파작업 시 충전매질에 따른 발파효과 비교 연구)

  • Bae, Sang-Soo;Han, Woo-Jin;Jang, Seung-Yup;Bang, Myung-Seok
    • Journal of the Korean Geosynthetics Society
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    • v.21 no.2
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    • pp.57-65
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    • 2022
  • This study simulated the shock wave propagation through the tamping material between explosives and hole wall at blasting works and verified the effect of tamping materials. The Arbitrary Lagrangian-Eulerian(ALE) method was selected to model the mixture of solid (Lagrangian) and fluid (Eulerian). The time series analysis was carried out during blasting process time. Explosives and tamping materials (air or water) were modeled with finite element mesh and the hole wall was assumed as a rigid body that can determine the propagation velocity and shock force hitting the hole wall from starting point (explosives). The numerical simulation results show that the propagation velocity and shock force in case of water were larger than those in case of air. In addition, the real site at blasting work was modeled and simulated. The rock was treated as elasto-plastic material. The results demonstrate that the instantaneous shock force was larger and the demolished block size was smaller in water than in air. On the contrary, the impact in the back side of explosives hole was smaller in water, because considerable amount of shock energy was used to demolish the rock, but the propagation of compression through solid becomes smaller due to the damping effect by rock demolition. Therefore, It can be proven that the water as the tamping media was more profitable than air.

Design of Riparian Buffer Zone by Citizen's Participation for Ecosystem Service - Case Study of Purchased Land along Gyeongan-cheon in Han River Basin - (생태계 서비스를 위한 주민 참여형 수변완충녹지 설계 고찰 - 한강수계 경안천변 매수토지 사례 연구 -)

  • Bahn, Gwon-Soo
    • Journal of Wetlands Research
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    • v.24 no.3
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    • pp.170-184
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    • 2022
  • The Riparian Buffer Zone(RBZ) is a sustainable social-ecological system created in the middle zone between water and land. For the RBZ, close communication with the local community is important, and it is necessary to promote it as a communicative environmental planning process. In this study, for the RBZ project, three strategies are presented as a communicative act to understand and implement planning. First, government-led projects were avoided and improved to a process in which citizens and stakeholders participated together, centered on local partnership. Second, it was intended to introduce design criterias in terms of enhancing the function of ecosystem services that citizens can sympathize with, and to increase acceptance and awareness through the planning of preferred spaces and facilities. Third, after a balanced plan for habitats, water cycle-based ecological environment, ecological experience and open space, citizens felt the restoration effect and value as an ecological resources, and a system was prepared to participate in the operation and management. This study will work as a process model based on citizens's participation. In addition, it will be possible to provide lessons for the change of the policy paradigm for the RBZ and the implementation of similar projects in the future.

ESG Evaluation and Response of Construction Companies in Korea (국내 건설기업의 ESG 평가 및 대응방안)

  • Park, Hwan-Pyo
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.6
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    • pp.785-796
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    • 2023
  • The adoption of Environmental, Social, and Governance(ESG) practices in domestic construction firms is predominantly driven by major corporations. These companies not only publish reports on their ESG management but also engage in a meticulous process of identifying key issues and setting priorities. This process entails an in-depth evaluation of the severity of various issues and the gathering of insights from experts in the field. Interestingly, a comparative analysis of ESG assessments for construction companies, both domestically and internationally, reveals significant discrepancies in outcomes. These differences stem from the varied evaluation methodologies and criteria employed by different assessing bodies. Addressing this gap, our study proposes a suite of strategies aimed at bolstering ESG management within the construction sector. We advocate for enhanced policy support and financial backing, especially targeting small and medium-sized enterprises(SMEs) to facilitate their engagement in ESG practices. A critical step forward involves the standardization and transparent disclosure of ESG evaluation criteria, tailored to reflect the unique aspects of the construction industry. Moreover, the standardization and publication of ESG assessments for subcontractors are essential, equipping them with the necessary tools for effective ESG management and evaluation. Given the global nature of construction projects, particularly those commissioned by the European Union in regions like Africa and East Asia, adherence to ESG standards is imperative. Our long-term vision includes the development of a comprehensive database detailing ESG regulations and their impacts, segmented by region and country. This repository will serve as a valuable resource for companies venturing into international construction projects.

Statistical Optimization of Culture Conditions of Probiotic Lactobacillus brevis SBB07 for Enhanced Cell Growth (프로바이오틱 Lactobacillus brevis SBB07의 균체량 증가를 위한 배양 조건 최적화)

  • Jeong, Su-Ji;Yang, Hee-Jong;Ryu, Myeong Seon;Seo, Ji Won;Jeong, Seong-Yeop;Jeong, Do-Youn
    • Journal of Life Science
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    • v.28 no.5
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    • pp.577-586
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    • 2018
  • We recently reported the potential probiotic properties of Lactobacillus brevis SBB07 isolated from blueberries. The present study investigates the effect of culture conditions such as temperature, initial pH, culture time, and medium constituent for industrial application. The ingredients of the medium to improve cell growth were selected by Plackett-Burman design (PBD) and central composite design (CCD) within a desirable range. The PBD was applied with 19 factors: seven carbon sources, six nitrogen sources, and six microelements. Protease peptone, corn steep powder (CSP), and yeast extract were found to be significant factors for the growth of SBB07. The CCD was then applied with three variables found from the PBD at five levels, and the optimum values were decided for the three variables: protease peptone, CSP, and yeast extract. In the case of the growth of SBB07, the proposed optimal media contained 2.0% protease peptone, 2.5% CSP, and 2.0% yeast extract, and the maximum dried-cell weight was predicted to be 2.93963 g/l. By the model verification, it was confirmed that the predicted and actual results are similar. Finally, the study investigated the effects of incubation temperature and initial pH at the optimized medium. It was confirmed that the dried-cell weight increased from $2.2933{\pm}0.0601g/l$ to $3.85{\pm}0.0265g/l$ when compared to the basal medium at $37^{\circ}C$ and initial pH 8.0. Establishing the optimal culture condition for SBB07 provides good potential for applications in probiotics and can serve as the foundation for the industrialization of materials.

Exposure Assessment for Polycyclic Aromatic Hydrocarbons in the Model Menu System of Korean (한국인의 모델식이에 대한 다환방향족탄화수소류(PAHs)의 인체노출량평가)

  • Kim YunHee;Yoon EunKyung;Lee HyoMin;Park KyungAh;Jun EunAh;Lee CherlHo;Choi SangYun;Lim SeungTaek;Ze KeumRyun;Choi KwangSik
    • Journal of Food Hygiene and Safety
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    • v.19 no.4
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    • pp.176-184
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    • 2004
  • This study was conducted to compare and estimate the daily PAHs dietary intake from both home-cooking and dining-out, through approach of model diet used in exposure assessment of food contaminants. Food commodities reflecting in model diet were selected from the KHIDI report and were analysed in cooked or uncooked edible forms using HPLC-Fluorscence Detector. The PAHs dietary intake comparison between home-cooking and dining-out was based on one meal intake suggested in model diet and PAHs dietary intake was estimated by using food consumption rate and body weight of the Korean adult group. The daily PAHs dietary intake was calculated by permutation and combination method with assumption that a person consumed 2 meals from home-cooking menu and 1 meal from dining-out menu. The total PAHs levels in 36 food commodities with 200 samples were ranged from 2.00 ug/kg to 141.28 ug/kg and a food showing the highest PAHs level was the stir-fried anchovy. The $TEQ_{BaP}$ levels of PAHs were calculated using benzo(a)pyrene equivalents individual congener level and corresponding TEF value and the $TEQ_{BaP}$ level were ranged from $0.03\;ugTEQ{BaP}$ to $1.31\;ugTEQ_{BaP}$ and a food showing the highest $TEQ_{BaP}$ level was the hamburger. The PAHs dietary intakes per one meal from home-cooking and dining-out were $2.4\times10^{-3}\;ugTEQ_{BaP}/kg/meal\;and\;4.0\times10^{-3}\;ugTEQ_{BaP}/kg/meal$, respectively. This data showed the PAHs dietary intake from dining-out was about 1.7 times higher than from the home-cooking. The daily PAHs dietary intakes of general Korean adult having two meals from home-cooking and one meal from dining-out per a day were ranged between $8.0\times10^{-3}\~9.7\times10^{-3}\;ugTEQ_{BaP}/gg/day$ and mean value as $8.9\times10^{-3}\~9.7\times10^{-3}\;ugTEQ_{BaP}/gg/day$.

The strengthening of North Atlantic Deep Water during the late Oligocene based on the benthic foraminiferal species Oridorsalis umbonatus (저서성 유공충 Oridorsalis umbonatus의 산출 상태에 기록된 후기 올리고세 북대서양 심층수의 강화)

  • Lee, Hojun;Jo, Kyoung-nam;Lim, Jaesoo
    • Journal of the Geological Society of Korea
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    • v.54 no.5
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    • pp.489-499
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    • 2018
  • A series of geological events such as the formation of the Antarctic continental ice sheets, the changes in ocean circulation and a mass extinction after the onset of Oligocene has been studied as major concerns by various researches. However, paleoclimatic and paleoceanographic changes during the most period of Oligocene since the Eocene-Oligocene transition (EOT) still remains unclear. Especially, although the late Oligocene warming (LOW) has been assessed as the largest period in the paleoceanographic changes, the detailed understanding on the changed components is very low. The purpose of this study is the reconstruction of the paleoceanographic history during the late Oligocene using core sediments from IODP Expedition 342 Site U1406 performed in J-Anomaly Ridge in North Atlantic. Because North Atlantic deep water (NADW) has flowed southward through the study area since the early Oligocene, this area has been considered to an important location for studies on the changes of NADW. The core sediment analyzed in this study were deposited from about 26.0 to 26.5 Ma as evidenced by both of onboard and shore-based paleomagnetic data, and this is corresponded to the earliest period of LOW. The sediment profile can be divided into three Units (Unit 1, 2 & 3) based on the changes in both of total number and test size of Oridorsalis umbonatus as well as grain size data of clastic sediments. Unit 2 represents largest values in these three data. Because the total number, test size of O. umbonatus and grain size can be proxy records on the oxygen concentration and circulation intensity of deep water, we interpreted that Unit 2 had been deposited during the period of relatively strengthened NADW. Previous Cibicidoides spp. stable isotope results from the low latitude region of the North Atlantic also support our interpretation that is the intensified formation of NADW during the identical period. In conclusion, our results present a new evidence for the previous ideas that the causes on LOW are directly related to the changes in NADW.

Numerical Study on Thermochemical Conversion of Non-Condensable Pyrolysis Gas of PP and PE Using 0D Reaction Model (0D 반응 모델을 활용한 PP와 PE의 비응축성 열분해 기체의 열화학적 전환에 대한 수치해석 연구)

  • Eunji Lee;Won Yang;Uendo Lee;Youngjae Lee
    • Clean Technology
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    • v.30 no.1
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    • pp.37-46
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    • 2024
  • Environmental problems caused by plastic waste have been continuously growing around the world, and plastic waste is increasing even faster after COVID-19. In particular, PP and PE account for more than half of all plastic production, and the amount of waste from these two materials is at a serious level. As a result, researchers are searching for an alternative method to plastic recycling, and plastic pyrolysis is one such alternative. In this paper, a numerical study was conducted on the pyrolysis behavior of non-condensable gas to predict the chemical reaction behavior of the pyrolysis gas. Based on gas products estimated from preceding literature, the behavior of non-condensable gas was analyzed according to temperature and residence time. Numerical analysis showed that as the temperature and residence time increased, the production of H2 and heavy hydrocarbons increased through the conversion of the non-condensable gas, and at the same time, the CH4 and C6H6 species decreased by participating in the reaction. In addition, analysis of the production rate showed that the decomposition reaction of C2H4 was the dominant reaction for H2 generation. Also, it was found that more H2 was produced by PE with higher C2H4 contents. As a future work, an experiment is needed to confirm how to increase the conversion rate of H2 and carbon in plastics through the various operating conditions derived from this study's numerical analysis results.

Study on the Fire Risk Prediction Assessment due to Deterioration contact of combustible cables in Underground Common Utility Tunnels (지하공동구내 가연성케이블의 열화접촉으로 인한 화재위험성 예측평가)

  • Ko, Jaesun
    • Journal of the Society of Disaster Information
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    • v.11 no.1
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    • pp.135-147
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    • 2015
  • Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.