• Title/Summary/Keyword: harmful factor

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A Study on the Analysis of $CO_2$ Concentration Variation According to the Indoor Space Condition Changes (다양한 실내 환경에서의 $CO_2$ 농도 변화 분석 연구)

  • Ahn, Gwang-Hoon;Kwon, Jong-Won;Kim, Gyu-Sik;Kim, Hie-Sik
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.347-349
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    • 2009
  • Air quality of indoor space environment is affected by various pollutants like as particles and chemical stuffs. The indoor air pollution affects directly the human respiration organs to cause consequently unpleasant mental status. The $CO_2$ concentration level is one of the harmful components of air pollutants. Major factor to increase the $CO_2$ concentration level is the people's breath amount in indoor. The car exhaust gas diffused from the around road also has strong affect on $CO_2$ concentration. There are some other reasons to affect the $CO_2$ concentration change, such as, real-time change of the population movement, closeness to the indoor air flow inlet window and changes in road car traffic amount. A remote monitoring system to measure environmental indoor air pollution concerning on the $CO_2$ concentration was studied and installed realized set-up model. Zigbee network configuration was applied for this system and the $CO_2$ concentration data were collected through USN network. A software program was developed to assure systematic analysis and to display real-time data on web pages. For the experimental test various condition was set up, like as, window opening, stopping air condition operation and adjusting fan heater work, etc. The analysis result showed the relation of various environmental conditions to $CO_2$ concentration changes. The causes to increase $CO_2$ concentration were experimentally defined as windows closing, the stopping air condition system, fan heater operation. To keep the $CO_2$ concentration under the legally required ppm level in public access indoor space, the developed remote measurement system will be usefully applied.

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A transient CFD simulation of ventilation system operation for smoke control in a subway station equipped with a Platform Screen Door(PSD) when a train under fire is approaching the station (화재열차의 역사 접근 시 PSD가 설치된 역사 제연을 위한 환기장치 운전 비정상상태 해석)

  • Shin, Kyu-Ho;Hur, Nahm-Keon;Won, Chan-Shik
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.269-272
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    • 2006
  • The heat and smoke which generated by subway under fire is one of the most harmful factor in air tighten underground station. To prevent this, Trackway Exhaust System(TES) can be used. The heat released from the train running in the tunnel raises the temperature at the platform and the trackway, and thus proper ventilation system is required for comfortable underground environment. When the fire is occurred, TES is operated as smoke exhaust mode from normal ventilation mode. In the present study, the subway station which is one of the line number 9 in Seoul subway is modeled, and fired situation is simulated with several ventilation mode of ventilation system in trackway. For this simulation whole station is modeled. Non steady state 3D simulation which considered train under fire is entering to the station is performed. Temperature and smoke distribution in platform and trackway are compared. To represent heat by fire, heat flux was given to the fired carriage, also to describe smoke by fire, concentration of CO is represented. As the result of present study, temperature and smoke distribution is different as the method of ventilation in trackway and platform is changed. In over side of trackway, the fan must be operated as exhaust mode for efficient elimination of heat and smoke, and supply mode of fan operation in under side shows better distribution of heat and smoke. The ventilation system which is changed from ventilation mode to exhaust mode can be applied to control heat and smoke under fire.

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Employment and Married Women's Health in Korea; Beneficial or Harmful? (기혼 여성의 직업이 신체적, 정신적 건강에 미치는 영향)

  • Kim, Il-Ho;Chun, Hee-Ran
    • Journal of Preventive Medicine and Public Health
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    • v.42 no.5
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    • pp.323-330
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    • 2009
  • Objectives : The aim of this study was to investigate whether working married women in different occupational classes affected diverse health outcomes. Methods : We used data for married women aged 25-59 (N=2,273) from the 2005 National Health and Nutritional Examination Survey. Outcome measures included physical/mental and subjective/objective indicators (selfrated poor health, chronic diseases, depression, and suicidal ideation from reported results; metabolic syndrome dyslipidemia from health examination results). Agestandardized prevalence and logistic regression were employed to assess health status according to three types working groups (housewives, married women in manual jobs, married women in non-manual jobs). Sociodemographic factors (age, numbers of children under 7, education, household income) and health behaviors (health examination, sleep, rest, exercise, smoking, drinking) and a psychological factor (stress) were considered as covariates. Results : Non-manual married female workers in Korea showed better health status in all five health outcomes than housewives. The positive health effect for the non-manual group persisted in absolute (age-adjusted prevalence) and relative (odds ratio) measures, but multivariate analyses showed an insignificant association of the non-manual group with dyslipidemia. Manual female workers showed significantly higher age-adjusted prevalence of almost all health outcomes than housewives except chronic disease, but the associations disappeared after further adjustment for covariates regarding sleep, rest, and stress. Conclusions : Our results suggest that examining the health impact of work on married women requires the consideration of occupational class.

Characterization of Nivalenol-Producing Fusarium culmorum Isolates Obtained from the Air at a Rice Paddy Field in Korea

  • Kim, Da-Woon;Kim, Gi-Yong;Kim, Hee-Kyoung;Kim, Jueun;Jeon, Sun Jeong;Lee, Chul Won;Lee, Hyang Burm;Yun, Sung-Hwan
    • The Plant Pathology Journal
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    • v.32 no.3
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    • pp.182-189
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    • 2016
  • Together with the Fusarium graminearum species complex, F. culmorum is a major member of the causal agents of Fusarium head blight on cereals such as wheat, barley and corn. It causes significant yield and quality losses and results in the contamination of grain with mycotoxins that are harmful to humans and animals. In Korea, F. culmorum is listed as a quarantine fungal species since it has yet to be found in the country. In this paper, we report that two isolates (J1 and J2) of F. culmorum were collected from the air at a rice paddy field in Korea. Species identification was confirmed by phylogenetic analysis using multilocus sequence data derived from five genes encoding translation elongation factor, histone H3, phosphate permease, a reductase, and an ammonia ligase and by morphological comparison with reference strains. Both diagnostic PCR and chemical analysis confirmed that these F. culmorum isolates had the capacity to produce nivalenol, the trichothecene mycotoxin, in rice substrate. In addition, both isolates were pathogenic on wheat heads and corn stalks. This is the first report on the occurrence of F. culmorum in Korea.

A Study on the Analysis of Hazardous Risk Factors for Component in Hydrogen Station with Water Electrolysis Device (수전해 수소충전소 부품별 유해위험요인 분석)

  • Seo, Doo-Hyoun;Rhie, Kwang-Won;Kim, Tae-Hun
    • Journal of the Korean Institute of Gas
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    • v.23 no.6
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    • pp.33-38
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    • 2019
  • In order to invigoration the hydrogen economy, production of hydrogen needed for hydrogen charging stations and hydrogen fuel cells is needed. Generally, it is reforming used to coal fuel or natural gas. Other technologies include water electrolysis using pure water. Among these water electrolysis technologies, development is mainly carried out using PEM(Polymer Electrolyte Membrane electrolysis). In this study, the company aims to identify potential harmful hazards to PEM electrolysis hydrogen stations in the development stage among hydrogen charging stations. In order to find the hazardous factors in the facilities of the electrolysis and hydrogen charging stations, we were analyzed by Failure Mode & Effect Analysis(FMEA).

Combination between Taxol-Encapsulated Liposomes and Eruca sativa Seed Extract Suppresses Mammary Tumors in Female Rats Induced by 7,12 Dimethylbenz(α)anthracene

  • Shaban, Nadia;Abdel-Rahman, Salah;Haggag, Amany;Awad, Doaa;Bassiouny, Ahmad;Talaat, Iman
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.1
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    • pp.117-123
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    • 2016
  • Taxol (paclitaxel) is a powerful anti-cancer drug widely used against several types of malignant tumors. Because Taxol may exert several side effects, a variety of formulations have been developed. One of these features liposomes, regarded as one of the most promising drug carriers, biocompatible and best able to reduce drug toxicity without changing efficacy against tumor cells. Eruca sativa seed extract (SE) is considered a promising natural product from cruciferous vegetables against breast cancer, increasing chemotherapeutic and eliminating harmful side effects. The effects of Taxol-encapsulated liposomes (T) alone and in combination between Eruca sativa seed extract on nuclear factor kappa B (NF-${\kappa}B$), cyclooxygenase-2 (COX-2) and B-cell lymphoma-2 (Bcl-2) gene expression levels were investigated in rat mammary gland carcinogenesis induced by 7,12 dimethylbenz(${\alpha}$) anthracene (DMBA) using qRT-PCR. The results showed that DMBA increased NF-${\kappa}B$, COX-2 and Bcl-2 gene expression levels and lipid peroxidation (LP), while decreasing glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities and total antioxidant concentration (TAC) compared to the control group. T and T-SE treatment reduced NF-${\kappa}B$, COX-2 and Bcl-2 gene expression levels and LP. Hence, T and T-SE treatment appeared to reduce inflammation and cell proliferation, while increasing apoptosis, GST and SOD activities and TAC.

A Numerical Analysis on the Collapse and Backfill Mechanism of the Abandoned Mine Cavity (폐광의 점진적 파괴 및 뒷채움 효과에 대한 해석적 연구)

  • Lee, Jun-Suk;Bang, C.S.
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.2 no.2
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    • pp.62-71
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    • 2000
  • The abandoned mines causing settlement of the surface above and collapse of the cavities are the major influencing factor on the stability of the nearby underground structures. To prevent the harmful effect, the backfill methods are commonly applied to the cavities although the design criteria and the analysis method are not properly addressed in some cases. An approximate analytical method together with the numerical technique is considered in this study to simulate the gradual deterioration of the rock masses around the cavities and, therefore, the influential zone to the underground structures passing through the cavities. Also considered in this study is the backfill effect on the stability of the rock masses around the cavities. Specifically, the incomplete backfill effect is compared with that of the idealized backfill method by adopting elasto-plastic analysis involving a strain softening material law.

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Lactobacillus Aggravate Bile Duct Ligation-Induced Liver Inflammation and Fibrosis in Mice

  • Roh, Yoon Seok;Cho, Ara;Cha, Youn-Soo;Oh, Suk-Heung;Lim, Chae Woong;Kim, Bumseok
    • Toxicological Research
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    • v.34 no.3
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    • pp.241-247
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    • 2018
  • Lactobacillus (LAB) have been reported to exert both harmful and beneficial effects on human and animal health. Recently, it has been reported that dysbiosis and bacterial translocation contribute to liver fibrosis. However, the role of Gram-positive LAB in the situation of chronic liver diseases has not been yet elucidated. Liver injury was induced by bile duct ligation (BDL) in LAB or control-administered mice. Liver fibrosis was enhanced in LAB-administered mice compared with control-treated mice as demonstrated by quantification of Sirius-red positive area, hydroxyproline contents and fibrosis-related genes ($Col1{\alpha}1$, Acta2, Timp1, Tgfb1). Moreover, LAB-administered mice were more susceptible to BDL-induced liver injury as shown by increased ALT and AST level of LAB group compared with control group at 5 days post BDL. Consistent with serum level, inflammatory cytokines ($TNF-{\alpha}$, IL-6 and $IL-1{\beta}$) were also significantly increased in LAB-treated mice. Of note, LAB-treated liver showed increased lipoteichoic acid (LTA) expression compared with control-treated liver, indicating that LAB-derived LTA may translocate from intestine to liver via portal vein. Indeed, responsible receptor or inflammatory factor (PAFR and iNOS) for LTA were upregulated in LAB-administered group. The present findings demonstrate that administration of LAB increases LTA translocation to liver and induces profibrogenic inflammatory milieu, leading to aggravation of liver fibrosis. The current study provides new cautious information of LAB for liver fibrosis patients to prevent the detrimental effect of LAB supplements.

Change in the photocatalytic activity of ZnO nanoparticles by additive H2O

  • Nam, Sang-Hun;Kim, Myoung-Hwa;Lee, Sang-Duck;Choi, Jin-Woo;Kim, Min-Hee;Boo, Jin-Hyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.285-285
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    • 2010
  • Zinc oxide (ZnO) is a direct band gap semiconductor with 3.37 eV, which has in a hexagonal wurtzite structure. ZnO is a good candidate for a photocatalyst because it has physical and chemical stability, high oxidative properties, and absorbs of ultraviolet light. During ZnO is irradiated by UV light, redox (reduction and oxidation) reactions will occur on the ZnO surface, generating the radicals O2- and OH. These two powerful oxidizing agents have been proven to be effective in decomposition of harmful organic materials, converting them into CO2 and H2O. Therefore, we assume that oxygen on the surface of ZnO is a very important factor in the photocatalytic activities of ZnO nanoparticles. Recently, ZnO nanoparticles are studied in various application fields by many researchers. Photocatalyst research is progressing much in various application fields. But the ZnO nanoparticles have disadvantage that is unstable in water in comparison titanium dioxide (TiO2). The Zn(OH)2 was formed at the ZnO surface and ZnO become inactive as a photocatalyst when ZnO is present in the solution. Therefore, we prepared synthesized ZnO nanoaprticles that were immersed in the water and dried in the oven. After that, we measured photocatalytic activities of prepared samples and find the cause of their phtocatalytic activity changes. The characterization of ZnO nanoparticles were analyzed by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and BET test. Also we defined the photocatalytic activity of ZnO nanoparticles using UV-VIS Spectroscopy. And we explained changing of photocatalytic activity after the water treatment using X-ray Photoelectron Spectroscopy (XPS).

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A Study of Perception on the MSG Usage and Self Recognized MSG Symptom Complex After Eating Out (외식섭취 후 MSG사용에 대한 인식과 MSG 복합증후군 자각경험에 대한 연구)

  • Kim, Up Sik;Chang, Hyun Chung;Han, Myung Joo
    • Journal of the Korean Society of Food Culture
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    • v.29 no.6
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    • pp.539-548
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    • 2014
  • The objective of this study was to determine the perception of monosodium glutamate (MSG) contents in eating out menu and MSG symptom complex. Respondents in the Seoul area were surveyed from Feb. 10 to 20, 2014. The results are summarized as follows. The 51.3% of respondents were male and 48.7% of them were female. As for age, 73.5% of respondents were 20~24 years old. Favorite menu of respondents' eating out were Korean food (57.8%), Western food (17.6%), Fast food (9.5%), Japanese food (6.2%), Chinese food (5.2%). Male respondents favored Korean food (62.4%), Fast food (10.2%) and Western food (9.6%), but female respondents favored Korean food (53.0%), Western food (26.2%) and Fast food (8.7%). The 48.7% of respondents considered Chinese food containing high amount of MSG. A few respondents (18.6%) recognized to usage amount of MSG as consideration factor to select eating out menu. However, most respondents (55.2%) perceived harmful to take excessive amount of MSG contained food. The 37.9% of respondents had experience of MSG symptom complex after eating out. Respondents' self recognized MSG symptom complex were thirstiness (84.5%), drowsiness (55.7%), weakness (34.5%), nausea (30.2%), tightness (20.7%) and headache (14.7%). The 19.9% of respondents like MSG contained food. The reason for disliking MSG contained food were 'bad for health' (66.3%) and 'MSG symptom' (33.2%). The reason for liking MSG contained food were 'good taste (83.6%) and 'habitual eating' (14.8%). The result of this study showed that some sensitive people have unpleasant reaction after eating out. Therefore, it is suggested that natural flavor enhancer may develop to replace the use of MSG.