• 제목/요약/키워드: Protection time

검색결과 2,887건 처리시간 0.03초

A Study on the Emission and Dispersion of Particulate Matter from a Cement Plant (한 시멘트공장의 분진발생과 대기확산에 관한 조사연구)

  • Chang, Man-Ik;Chung, Yong;Kwon, Sook-Pyo
    • Journal of Preventive Medicine and Public Health
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    • 제16권1호
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    • pp.67-77
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    • 1983
  • To investigate the an air pollution by particulate matter and its dispersion, a cement plant produceing portland cement 600,000 ton/year and its vicinity were surveyed from Obtober, 1980 to April, 1983. The survey was mainly focused on main stack emmission rate of the cement plant and particle size distribution in the dust, dustfall and total suspended particulate concentration in the area by month and distance from the stack. The results of the study were as follows; 1. The main stack emission rate was surveyed before and after the spray tower was additionally installed to the original E.P bag filter. Before the spray tower installed, the main stack emission rate was higher ($0.64g/Nm^3$) than the emission standard of Korean Environmental Preservation Law's ($0.59g/Nm^3$, amended to $0.4g/Nm^3$ on April 1983), but after the spray tower was installed, its main stack emission rate was markedly decreased to the standard ($0.43g/Nm^3$). 2. $2{\sim}3{\mu}m$ of the particle size was the largest portion (20.8%) of the dust particulate from the main stack and 50% of the frequency distribution was $1.5{\mu}m$ of the size. Most particle size was below $10{\mu}m$. 3. The spray tower reduced the dustfall to $37.81{\sim}9.76\;ton/km^2/month$ while dustfall appeared at $45.29-15.45ton/km^2/month$, in the vicinity of plant before spray tower installed 4. Mean concentrations of total suspended particulate for 24 hours of the various stations were determined in $20.6-200.0{\mu}g/m^3$, 3 stations of tham were higher than the value of Harry and William's arthmetic average standard $130{\mu}g/m^3$. 5. Linear regression between dustfall [X] and total suspended particulate[Y] concentration was an equation, Y=4.024X+11.479.[r=0.91] 6. During the whole seasons in the opposite area 100m apart from the omission source the prevailing wind direction was with estimated more than $30ton/km^2/month$, and the concentration of total suspended particulate for 24 hours averaging time was more than $140{\mu}g/m^3$ in the same area and direction. 7. Assuming the wind direction were constant through the day dustfalls for a day were estimated at $13.40ton/km^2/day,\;10.79ton/km^2/day$ and $4.55ton/km^2/day$ at various distances of 100m, 500m and 1,500m from the emission source respectively. 8. In the simutalion of dustfall and suspended dust by area, Gaussian dispersion model modified by size distribution of particulate matter was not applicated since the emission of dust were from multi sources other them stack. From the above results, it could be applied that the dispersion of dust from the cement plant is estimated and regulated for the purpose of environmental protection.

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Protection of Primary Cultured Mouse Hepatocytes from Chemical Hypoxia-induced Injury by Hydrogen Sulfide (화학적 허혈에 의해 손상된 마우스 간세포에 대한 hydrogen sulfide의 간세포 보호 효과)

  • Lee, Min Young
    • Journal of Life Science
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    • 제23권11호
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    • pp.1342-1350
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    • 2013
  • We examined the effect of hydrogen sulfide ($H_2S$) in chemical hypoxia-induced injury in mouse hepatocytes. Cell viability was significantly decreased by cobalt chloride ($CoCl_2$), a well-known hypoxia mimetic agent in a time- and dose- dependent manner. Sodium hydrosulfide (NaHS, a donor of $H_2S$) pretreatment before exposure to $CoCl_2$ significantly attenuated the $CoCl_2$-induced decrease of cell viability. $CoCl_2$ treatment resulted in an increase of intracellular ROS generation, which is inhibited by NaHS or N-acetyl-cysteine (NAC, a ROS scavenger), and p38 MAPK phosphorylation, which is also blocked by NaHS or NAC. The $CoCl_2$-induced increase of the Bax/Bcl-2 ratio was attenuated by NaHS, NAC, and SB 203580 (p38 MAPK inhibitor). The $CoCl_2$-induced decrease of cell viability was also attenuated by NaHS, NAC, and SB 203580 pretreatment. Additionally, NaHS inhibited the $CoCl_2$-induced COX-2. Similar to the effect of NaHS, NAC blocked $CoCl_2$-induced COX-2 expression. Furthermore, NS-398 (a selective COX-2 inhibitor) attenuated not only the $CoCl_2$-induced increase of the Bax/Bcl-2 ratio, it also decreased cell viability. Taken together, $H_2S$ protects primary cultured mouse hepatocytes against $CoCl_2$-induced cell injury through inhibition of the ROS-activated p38 MAPK cascade and the COX-2 pathway.

Recovery Pattern and Seasonal Dynamics of Kelp Species, Ecklonia cava Population Formed Following the Large-scale Disturbance (대규모 교란현상 후 형성된 대형갈조류 감태(Ecklonia cava) 개체군의 계절적 변동 및 회복 양상)

  • KIM, SANGIL;KANG, YUN HEE;KIM, TAE-HOON;PARK, SANG RUL
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • 제21권3호
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    • pp.103-111
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    • 2016
  • Seasonal dynamics of kelp forest-forming algae, Ecklonia cava population formed following the large-scale disturbance by Typhoon 'Bolaven' in August 2012 were investigated in Jeju Island, Korea. Morphological characteristics, recruits density, mortality rate, total density and biomass were monitored bimonthly from June 2013 to June 2015. Total and longest blade lengths, and individual weight of E. cava showed distinct seasonal trends. Stipe length increased from winter to spring, but did not show increase or reduced from summer to autumn. This indicates that morphological characteristics of E. cava are mainly affected by the change of blades. The optimal temperature for E. cava growth was about $15-18^{\circ}C$ during winter to spring while the growths were inhibited at the water temperature above $20^{\circ}C$ during summer. E. cava exhibited very low recruitment during spring-summer. However, high recruitment was observed on April 2015 when canopy cover was very low due to low density. This indicates that recruitment of E. cava was controlled not by seasonal effects but by physical factors such as canopy and space. The mortality rate of juvenile plants was highest due to their unstable settlement. By June 2015, 34 months after the disturbances, E. cava was almost recovered to the pre-disturbance population size structure. These results suggest that recovery of kelp forest following the large-scale disturbance requires a considerable period of time (more than three years). This study should provide valuable ecological information on management, restoration and protection of kelp species.

A study on the evaluation of fire safety according to the ventilation mode in a train fire at the subway platform (지하철 승강장에서 열차 화재시 제연모드에 따른 화재 안전성 평가 연구)

  • Ryu, Ji-Oh;Lee, Hu-Young
    • Journal of Korean Tunnelling and Underground Space Association
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    • 제22권3호
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    • pp.293-310
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    • 2020
  • The purpose of this study is to present the most effective smoke exhaust mode by comparing the quantitatively evaluated risks according to the smoke exhaust mode when a train fire occurs in a subway platform. Therefore, applying the typical subway platform as a model, train fire scenarios are developed with the evacuation start time and location of the fire train for each exhaust mode. The fire accident rates (F) are calculated and the number of fatalities (N) was quantitatively estimated by fire analysis and evacuation analysis for each scenario. In addition, the F/N curve compared with the social risk assessment criteria and the following conclusions were obtained. In the event of a train fire at the subway station platform, the evacuation must start up within 600 s in maximum to ensure the evacuees' safety. To secure evacuation safety, it is advantageous to operate the HVAC system of the platform in the air-supply mode at station without TVF. Comparing the F/N curve for each exhaust mode with the social risk criteria, it turned out that the risk significantly exceeds the social risk criteria in case of no mechanical ventilation. As a result, this paper shows that the ventilation mode in which TVF are exhausted and HVAC system is operated in the pressurized mode are the most effective smoke exhaust mode for ensuring evacuation safety.

Acaricidal Efficacy of Herbal Extracts against Tetranychus urticae (Acarina: Tetranychidae) (점박이응애, Tetranychus urticae (Acarina: Tetranychidae)에 대한 약용식물 추출물의 살비 효과)

  • Lee, Jung-Su;Ham, Eun-hae;Choo, Ho-Yul;Lee, Suk-Jun;Lee, Dong-Woon
    • Journal of agriculture & life science
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    • 제45권6호
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    • pp.151-162
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    • 2011
  • Methanol and hexane extracts from 35 species in 27 families of herbal plants were evaluated for their acaricidal activities against two-spotted spider mite, Tetranychus urticae by leaf-dipping and spraying methods in laboratory, pot and field, respectively. Acaricidal activities were different depending on herbal plants. When T. urticae was released on leaves of Phaseolus vulgaris var. humilis that were dipped in the 1,000 ppm hexane extracts from fruits of Torreya nucifer and Daphan genkwa, seeds of Xanthium strumarium and Pharbitis nil at one minute they experienced 56.8, 47.8, 47.7, and 47.7% mortalities, respectively. Dipping time influenced acaricidal activity, that is, one minute dipping was more effective than 30 second dipping of Phaseolus vulgaris var. humilis leaves. However, extracts of X. strumarium and P. nil seeds had comparatively high activities. Concentration of hexane extract of X. strumarium and P. nil seeds revealing LC50 were 1,824 and 1,899 ppm, respectively. Extracts of both plants from hot and cold water were not effective representing <20% mortality at 1,000 ppm. However, hexane extracts of X. strumarium and P. nil seeds were effective against T. urticae on P. vulgaris var. humilis representing 76.3 and 71.3% mortalities in pot, respectively. Control effects of hexane extract of P. nil seed were 50.8 and 35.1% at 2,000 and 1,000 ppm against T. urticae on Chrysanthemum morifolium in greenhouse, respectively.

A New Spray Chrysanthemum Cultivar, 'Magic Yellow' with Single Type and Bi-Color Petals for Cut Flower (복색 홑꽃 절화용 스프레이국화 '매직옐로우' 육성)

  • Hwang, Ju Chean;Chin, Young Don;Chung, Yong Mo;Kim, Su Kyeong;Ro, Chi Woong;Jeong, Byoung Ryong
    • FLOWER RESEARCH JOURNAL
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    • 제19권3호
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    • pp.172-176
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    • 2011
  • A new spray chrysanthemum (Dendranthema grandiflorum) cultivar, 'Magic Yellow' was developed from a cross between 'Artist pink' and 'S03-47' by selection of seedlings and lines at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) from 2003 to 2008. Its characteristics were investigated three times from 2006 to 2008 under condition of forcing culture in spring and retarding culture in autumn. The natural flowering time of 'Magic Yellow' was October 18th, and year-round production was possible by day length treatment. This cultivar has single-type flowers in good harmony with bi-color ray floret and green center. Its flower was 6.0 cm in diameter, and it had 11.4 flowers per stem in autumn. The days to flowering under the short day treatment is about 45 days in spring season, and 'Magic Yellow' showed the vase life of 22.9 days in autumn. This cultivar was registered for the protection in 2008.

A New Spray Chrysanthemum Cultivar, 'Dimple' with Single Type and Bright Yellow Color Petals for Cut Flower. (밝은 황색 절화용 홑꽃 화형의 스프레이국화 '딤플' 육성)

  • Hwang, Ju Chean;Chin, Young Don;Chung, Yong Mo;Kim, Su Kyeong;Ro, Chi Woong
    • FLOWER RESEARCH JOURNAL
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    • 제19권4호
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    • pp.259-263
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    • 2011
  • A new spray chrysanthemum (Dendranthema grandiflorum) cultivar, 'Dimple' was developed from a cross between 'champy' and 'SP05-135', by selection of seedlings and lines at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) from 2005 to 2009. Its characteristics were investigated three times from 2007 to 2009 under condition of forcing culture in spring and retarding culture in autumn. The natural flowering time of 'Dimple' was October 24th, and year-round production was possible by day-length control. This cultivar has single type flowers with bright yellow ray floret and green center. The plant is very vigorous and very stable in the color of petals when it is cultivated even under high temperature condition in summer. Its flower was 4.7 cm in diameter, and it had 20.3 flowers per stem in autumn. The days to flowering under the short day treatment is about 50 in spring season, and 'Dimple' showed the vase life of 21.3 days in autumn. This cultivar was registered for the protection in 2009.

The status quo and developing measurement of water reuse in China

  • Li, Wei;Li, Jing;Wang, Yiwen;Zhong, Yuxiu;Liu, Hongxian;Li, Peilei
    • Proceedings of the Korea Water Resources Association Conference
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    • 한국수자원학회 2015년도 학술발표회
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    • pp.228-228
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    • 2015
  • Water reuse plays significant role in water saving and water environmental protection, and it helps alleviate the shortage of water resources. China's water reuse was put into practice since 1980s by means of pilot and promotion in National Fifth-year Plan and other strategies. The effects of water reuse is beneficial in both economic, social and environmental aspects. But some shortcomings still undermine future development of water reuse in China. To overcome and boost water reuse, Ministry of Water Resources conducted a successive survey across China. The aim of this study is to demonstrate the current condition of water reuse in China in construction, funds, legislation, planning, policy aspects, to summarize problems and its reasons underneath, to make suggestions for further development. Basically, in 2010, China's water reuse is 2.83 billion cubic meters and the utilization rate is 10.35%. Water reuse in China has four major characteristics: the first one is water reuse differences in amount occur national-widely and North of China has the main percentage as 47.3%; the second one is water reuse is mainly in environment maintenance (42.1%) and industry cooling (29.8%); the third one is funds for water reuse station and pipe construction is main in non-fiscal budget which take percentage as 56.8%; the fourth one is progresses of administrative system, political system, price management, standard system and technologies go rapidly recently. The problems of water reuse such as lack in water reuse station, delay in pipe constriction and limits on water reuse amount still exist due to some reasons. As a think tank of Ministry of Water Resources, we give some suggestions: firstly, water reuse needs to be integrated with traditional water resources allocation; secondly, public budgets need to be strengthened and income mechanism should also be constructed; thirdly, water resources integrated administrative of city and county should be boosted and roles as water reuse need to be clear and precise; fourthly, national, provincial and regional water reuse planning should be made in time; fifthly, regulations on water reuse should be programmed as soon as possible.

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A Study on the Azolla imbricata using as a Cosmetic Active Ingredient (물개구리밥(Azolla imbricata)을 이용한 주요 활성성분의 분리 및 화장품 소재 개발 연구)

  • Song, Min-Hyeon;Bae, Jun-Tae;Lee, Geun-Su;Zhang, Yong-He;Pyo, Hyeong-Bae
    • Journal of the Society of Cosmetic Scientists of Korea
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    • 제36권1호
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    • pp.71-77
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    • 2010
  • The water fern Azolla belongs to the Azollaceae and forms a symbiotic association with a $N_2$-fixing cyanobacterium, referred to as Anabaena azollae, and this association has currently been demonstrated to have potential as a nitrogen source for rice production. Because of that, Azolla fern has been used not only as organic manure in southern China and northern Vietnam for a long time but also as food for animate creatures in the underwater and decontaminant in the water. However, the phenolic compounds and active materials of Azolla have not been examined in detail in the past studies. In the present study, anti-oxidant ability test and experiment to find a particular active material of Azolla imbricata and Azolla imbricata fraction (AIF) were performed. In anti-oxidant test such as DPPH test and lipoxygenase inhibition test, the value of test represented high activities compared with authentic sample - green tea and NDGA (nordihydroguaiaretic acid). In MMP-1 test, related to collagen protection and elasticity of skin, its inhibitory effect was measured over 75 %, and the phenolic compounds of AIF related with this activity were confirmed luteolin derivatives by using FT-IR spectroscopy, element analyzer (EA) and Liquid chromatography-MASS spectroscopy.

Cognitive improvement effects of Momordica charantia in amyloid beta-induced Alzheimer's disease mouse model (여주의 amyloid beta 유도 알츠하이머질환 동물 모델에서 인지능력 개선 효과)

  • Sin, Seung Mi;Kim, Ji Hyun;Cho, Eun Ju;Kim, Hyun Young
    • Journal of Applied Biological Chemistry
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    • 제64권3호
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    • pp.299-307
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    • 2021
  • Accumulation of amyloid beta (Aβ) and oxidative stress are the most common reason of Alzheimer's disease (AD). In the present study, we investigated the cognitive improvement effects of butanol (BuOH) fraction from Momordica charantia in Aβ25-35-induced AD mouse model. To develop an AD mouse model, mice were received injection of Aβ25-35, and then orally administered BuOH fraction from M. charantia at doses of 100 and 200 mg/kg/day during 14 days. In the T-maze and novel object recognition test, administration of BuOH fraction from M. charantia L. at doses of 100 and 200 mg/kg/day improved spatial ability and novel object recognition by increased explorations of novel route and new object. In addition, BuOH fraction of M. charantia-administered groups improved learning and memory abilities by decreased time to reach hidden platform in Morris water maze test. Oral administration of BuOH fraction from M. charantia significantly inhibited lipid peroxidation and nitric oxide levels in the brain, liver, and kidney compared with Aβ25-35-induced control group. These results indicated that BuOH fraction of M. charantia improved Aβ25-35-induced cognitive impairment by attenuating oxidative stress. Therefore, M. charantia could be useful for protection from Aβ25-35-induced cognitive impairment.