• Title/Summary/Keyword: Vent control

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Occurrence of Culex pipiens (Diptera, Culicidae) and Effect of Vent Net Sets for Mosquito Control at Septic Tanks in South-eastern Area of the Korean Peninsula (한반도 동남부 지역 정화조 내의 빨간집모기군(群)(Culex pipiens complex) 발생과 정화조 환기통의 방충망 설치에 의한 방제효과)

  • Lee Dong-Kyu
    • Korean journal of applied entomology
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    • v.45 no.1 s.142
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    • pp.51-57
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    • 2006
  • Culex pipiens complex larvae were found at the septic tanks in Busan and Ulsan cities located in South-eastern area of Korean peninsula. The larvae were collected in 25, 35 and 75 septic tanks out of 3,527, 622 and 1,111 septic tanks which the breeding rates were averages of 0.7%, 5.6% and 6.8% in Busan from January to May, 2003; Busan from February to March, 2004; and Ulsan from January to April, 2005, respectively. The average numbers of the mosquitoes in the tanks were 38.8, 14.9 and 13.7 larvae/dip with a 355-ml dipper. The larval densities were from 25.4 larvae/dip in January to 43.7 larvae/dip in April. 2003 which were not significantly different between them. It was the first report to find mosquito breeding at septic tink in Republic of Korea. Culex pipiens larvae were found in 6 out of 379 septic tanks at complex buildings (over $2,000m^2$ in size) in Ulsan from June to September, 2005, having an average of 1.6% for mosquito breeding rate. The mosquito larvae were collected in 8 and 530 septic tanks out of 210 and 3,729 septic tanks at large (over 300 homes) and small apartments (below 300 homes) with 3.8% and 14.2% of the average breeding rates, respectively At the septic tanks of private houses for below 50 persons, 708 out of 7,178 septic tan had Cx. pipiens larvae and pupae with 9.9% of the average breeding rate. Total average of the mosquito breeding rate was 10.9% of the investigated septic tanks of residential buildings in Ulsan. The number of mosquito larvae in the septic tanks were 15 to 75 larvae/dip. The bent net sets of septic tanks prevented from mosquito breeding to the rate of 93.1%.

A study on measures for the mitigation of fire damage in Korea super high-rise building through the improvement of domestic·foreign standards (국·내외 기준개선을 통한 국내 초고층 건축물의 화재피해경감 대책에 관한 연구)

  • Ko, Jaesun
    • Journal of the Society of Disaster Information
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    • v.13 no.2
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    • pp.233-248
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    • 2017
  • Uniform laws and regulations and reasonable design is necessary for the prevention of possible fire in super high-rise building. To this end, this study focused on super high-rise and massive building-related architectural review performance-based design (PBD) evaluation disaster impact assessment (DIA), and provided fire engineering measures for improving fire prevention on the basis of performance-based design by analyzing the buildings subject to these systems and problems in terms of contents. Above all, in the aspect of law and standard improvement, first, with regard to dual parts of two statutes though significant portion of them has the same contents in performance-based design (PBD) evaluation and disaster impact assessment (DIA), it is necessary to operate the systems after making them conform with each other and consolidating or abolishing them. Second, if it is impossible to consolidate or abolish performance-based design (PBD) evaluation and disaster impact assessment (DIA), the areas of contents of performance-based design (PBD) evaluation and disaster impact assessment (DIA) should be precisely classified and established. Next, engineering improvement measures against fire hazard in super high-rise building are as follows. First, it is necessary to revise the provisions of straight-run stairs in special escape stairs. And in case of installing a mechanical smoke exhaust system instead of smoke vent, sandwich pressurization used in the United Stated should be permitted. Second, with regard to smoke control system for special escape stairs, it was shown that there was necessity for revising the standards in order to enable air to be supplied according to section in case of fire, carrying out performance-based design, and the like from the early design stages to the completion stages. In the future, it is expected that an epoch-making contribution will be made to a decrease in casualties and property damage due to fire in case of super high-rise building where the results can be reflected after carrying out a study on maintenance and carrying out an additional study on other considerations of super high-rise building together with reflecting the improvement measures provided in the above-mentioned study.

Comparison of the Bacterial and Fungal Colonies from Rana dybowskii which Collected from Inside and Outside Frog Farms and Identification of the Bacteria from the Tadpoles (개구리 증양식장 내·외부에서 채집된 북방산개구리(Rana dybowskii)로부터 검출된 세균과 곰팡이 콜로니 수의 비교 및 유생으로부터 확인된 세균 규명)

  • Kwon, Sera;Park, Daesik;Choi, Woo-Jin;Park, Jae-Jin;Cho, Han-Na;Han, Ji-Ho;Lee, Jin-Gu;Koo, Kyo-Soung
    • Korean Journal of Environment and Ecology
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    • v.31 no.5
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    • pp.444-454
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    • 2017
  • There are many ongoing studies of infectious diseases as the major factor responsible for global declining of the amphibian population. Although some point out the amphibian rearing facilities like frog farms as one of the important sources of harboring and spreading amphibian infectious pathogens in the wild, there have been few related studies in South Korea. In this study, we investigated the bacterial and fungal colonies on the skin and in the internal organs of frogs and tadpoles collected inside and outside of Dybowski's brown frog farms in Inje, Goesan, and Gongju to compare the difference according to the region and between inside and outside the farm. We also intended to classify the bacteria collected from the tadpoles into species by analyzing 16s rDNA gene sequences. The result showed that the number of bacterial colonies found in the skin and gut of frogs and the number of fungal colonies found in the skin and liver of frogs collected in Goesan was significantly greater than those in the frogs in Inje. However, there was no difference between the frogs collected inside and outside of farms in both regions. In the case of tadpoles, the number of fungal colonies in the tadpoles collected from Gongju was greater than that in the tadpoles collected from Inje. The comparison of inside and outside frog farms showed that there were more bacterial colonies on the skin of the tadpoles collected from inside than outside the frog farm in Inje and more bacterial colonies in the organs of the tadpoles collected from outside than inside the farm in Gongju. The frogs with higher condition factor (body weight/snout-vent length*100) showed fewer bacterial colonies on the skin and fewer fungal colonies in the heart, but there were no significant relationships in tadpoles. We identified the total of 15 genera and four phyla of bacteria, but the difference according to regions and between inside and outside farm was not evident. The result of this study indicates that the different conditions according to the locality of farm and between inside and outside farm cause the difference in the population sizes of bacterial and fungal colonies and that it can affect the overall health condition of Dybowski's brown frogs in the farm. Moreover, the result suggests that effective disease control in the facility is greatly necessary to ensure successful operation of amphibian rearing facility and to prevent the possible spread of diseases from the facility to the wild.

Long-term Climate Change Research Facility for Trees: CO2-Enriched Open Top Chamber System (수목의 장기 기후변화 연구시설: CO2 폭로용 상부 개방형 온실)

  • Lee, Jae-Cheon;Kim, Du-Hyun;Kim, Gil-Nam;Kim, Pan-Gi;Han, Sim-Hee
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.1
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    • pp.19-27
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    • 2012
  • The open-top chamber (OTC) system is designed for long term studies on the climate change impact on the major tree species and their community in Korea. In Korea Forest Research Institute (KFRI), the modified OTC system has been operating since September 2009. The OTC facility consists of six decagon chambers (10 meters in diameter by 7 meters high) with controlled gas concentration. In each chamber, a series of vertical vent pipes are installed to disperse carbon dioxide or normal air into the center of the chamber. The OTC is equipped with remote controlled computer system in order to maintain a stable and elevated concentration of carbon dioxide in the chamber throughout the experimental period. The experiment consisted of 4 treatments: two elevated $CO_2$ levels ($1.4{\times}$ and $1.8{\times}$ ambient $CO_2$) and two controls (inside and outdoors of the OTC). Average operational rate was the lowest (94.2%) in June 2010 but increased to 98% in July 2010 and was 100% during January to December 2011. In 2010~2011, $CO_2$ concentrations inside the OTCs reached the target programmed values, and have been maintained stable in 2011. In 2011, $CO_2$ concentrations of 106%, 100% and 94% of target values has been recorded in control OTC, $1.4{\times}$ $CO_2$-enriched OTC and $1.8{\times}$ $CO_2$-enriched OTC, respectively. With all OTC chambers, the difference between outside and inside temperatures was the highest ($1.2{\sim}2.0^{\circ}C$) at 10 am to 2 pm. Temperature difference between six OTC chambers was not detected. The relative humidity inside and outside the chambers was the same, with minor variations (0~1%). The system required the highest amount of $CO_2$ for operation in June, and consumed 11.33 and 17.04 ton in June 2010 and 2011, respectively.