• Journal of Korean Society of Environmental Engineers
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• v.38 no.8
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• pp.435-443
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• 2016

In this study, MACT (Maximum Achievable Control Technology) application effect was evaluated for minimization of benzene fugitive emission in petrochemical industry. Although fugitive emission for benzene in the nation was regulated by the Clean Air Conservation Act from 2015, the US EPA already has introduced MACT standard to minimize its emission with up-to-date technology since 1995. EPA Emission Factor (AP-42) and EPA MACT Standard Guideline were used to assess MACT application effect. As a result, For MACT application it could reduce benzene emission up to 98% (average) comparing with uncontrolled facility, while the national regulation could achieve about 95% (average) reduction which is slightly lower than MACT. However there is no control measure in the national regulation to reduce benzene emission for vessel loading even though MACT standard requires preventive facility such as VRU (Vapor Recovery Unit). For further reduction of benzene emission, it needs to be mandatory for operation of VRU when benzene product is loaded in vessel. These efforts could contribute to achieve the global level for benzene emission management in national petrochemical industry.

• Current Research on Agriculture and Life Sciences
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• v.16
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• pp.84-95
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• 1998

Apple Marssonina blotch, caused by Diplocarpon mali, which has been increasing on apple trees and become one of the most serious diseases on apple trees in Korea since the begining of 1990's. In this study, ecology of Marssonina blotch including disease incidence and spore dispersals was surveyed from 1992 to 1995 in Kyungpook, and factors influencing the incidence of the disease were analyzed. Marssonina blotch began to occur on apple leaves in June and was observed commonly in most of apple orchards after August, and increased rapidly in September. The incidence of this disease was high at the year of low temperature and a lot of precipitation. The conidia discharge began to occur in May and continued to October, and the peak period of spore release was in August and usually more than 70% of total spore release of the year released from August to September. The incidence of the disease was high in the northern and mountain are as such as Yeongjoo, Chungsong, Andong, and relatively low in the southern areas such as Kunwi, Yongchon. Jonathan cultivar was the most susceptible to Marssonina blotch, and Jonagold, Sekaiichi was secondly susceptible and the next Fuji was more susceptible than Tsugaru. The incidence of the disease was relatively high in orchards which cultivation management of irrigation, drainage, air circulation, fertilization, and fungicide spraying were poor.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.3-3
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• 2010

GM 들잔디의 환경위해성평가는 유전자변형생물체의 국가간이동등에 관한 법률 (2008년)에 안전관리 및 시험평가가 수행되었다. 일반적으로 GM 작물의 환경위해성평가는 도입 유전자의 안정적 발현여부, 일반적으로 사용되어온 식물과의 실질적 동등성, 화분비산에 의한 유전자이동성 검정, GM재배작물 주변 환경에 미치는 영향, GM작물 및 유전자의 인체 및 동물에 대한 안전성 평가, 위해성 관리 등이 있다. 본 발표에서는 제초제저항성 GM 들잔디를 실용화 하기위한 환경위해성평가의 내용을 소개하기 위하여 GM 들잔디의 안전성평가를 수행한 포장시험에 대해서 간략히 발표하고자 한다. GM 들잔디는 제초제저항성 유전자가 식물체내에 1개의 복제수를 갖으며, 후세대에서도 안정적으로 발현되었다. 또한 TAIL PCR을 통한 도입 유전자의 삽입 부위를 확인하였고, 주변염기서열을 이용한 JG21 들잔디 만의 특이적 염기서열을 얻었다. GM 들잔디의 실질적 동등성검정은 격리온실 수준과 격리포장 수준에 생물학적, 화학적 특성을 조사하였고, 일반 들잔디와 큰 차이가 없음을 확인하였다. GM 들잔디의 화분은 일광조건하에서 약 1시간 이내에 불활성 되었고, 실내의 실온조건에서는 3시간까지 활성이 유지되었다. GM 들잔디 재배포장 ($12m{\times}6m$ 크기)으로부터 화분비산 밀도는 3 m 이내에서 높게 나타났고, 9 m 이상의 거리에서는 낮은 빈도로 일정하게 나타났다. 화분비산에 의한 GM 들잔디 유전자이동성은 근접거리에서 약 15%가 관찰되었고, 반경 3 m 이내에서 거리에 따라서 2 ~ 0.12%의 유전자이동성이 관찰되었다. 각각의 시험모형에 따른 GM 들잔디와 일반들잔디 간의 교잡율을 조사한 결과 들잔디 교잡율은 GM 잔디의 면적과 거리에 의존적이었고, GM 들잔디 면적에 따라서 6-21%의 교잡율이 나타났다. GM들잔디의 인체위해성평가는 독성 및 알레르기 반응성을 검정하였고, 도입유전자 산물인 PAT 단백질은 독성 및 알레르기 반응성이 없음이 알려져 있다. 본 연구에서는 GM들잔디의 독성 및 알레르기 반응성을 검토한 결과 아플라톡신 등의 독성은 검출되지 않았으나, GM과 일반 들잔디 모두에서 화분 알레르기 반응성이 양성으로 나왔다. 그러나 GM들잔디에 도입된 유전자에 의한 알레르기 반응이 아닌 일반들잔디 화분에 가진 알레르겐에 의한 반응성이라 할 수 있다. GM들잔디의 비의도적 방출가능성을 조사하기위하여 시험포장외부의 자연환경에 대해서 환경모니터링을 수행한 결과 GM 들잔디의 유출 및 유전자이동 의한 제초제저항성 들잔디는 나타나지 않았다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.265-266
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• 2002

휘발성 유기화합물(Volatile Oraganic Compounds: VOCs)은 오존 등의 광화학 스모그 생성의 원인물질일 뿐만 아니라 발암성의 유해물질, 지구온난화, 대기중의 악취물질 등으로 환경 및 건강에 악영향을 초래한다. 최근 들어 VOCs에 대한 대기중 배출규제가 강화됨에 따라 이를 효과적으로 제거 또는 회수하는 연구가 매우 중요시되고 있으며, 활성탄을 이용한 흡착은 이러한 기체상의 VOCs 분자를 고체 흡착제에 약한 분자력의 인력에 의해 접촉시켜 분리하는 공정으로 회수율 및 에너지 절약의 관점에서 효과적인 방법으로 알려져 있다. (중략)

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.5
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• pp.254-259
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• 2012

The mechanical property enhancement was studied using fly ash produced from fluidized bed type boiler in power plant, which contains a lot of Ca component being used to carbonate for $CO_2$ fixation in the lightweight aggregates made of cement and some portion of fly ash as a cement substitution under the supercritical condition. Specimens having various fly ash substitution rates and curing periods were carbonated under the supercritical condition at $40^{\circ}C$. The weight change rate, carbonation rate by TG/DTA analysis, 1% Phenolphthalein test, specific gravity and mechanical compression strength test were performed to observe the mechanical property enhancement of the cemented materials after carbonation under the supercritical condition and to make sure those could be classified as lightweight aggregates having specific gravity under 2.0.

• Resources Recycling
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• v.27 no.3
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• pp.58-65
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• 2018

For the recycling of coal ash from the domestic circulating fluidized bed boilers, a lime-based sorbent with 0.2~0.4 mm size was prepared by using limestone powder and CFBC fly ash. Mixing a small amount of slaked lime in the lime-based absorbent lead the formation of calcium silicate on the surface of the particle and the strength of absorbent particle was improved. As a result of comparing the desulfurization characteristics, it was found that the conversion rate was about 10% higher than that of commercially available limestone desulfurization used in the furnace, which is confirmed that it can be used as a desulfurization absorbent.

• Journal of ILASS-Korea
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• v.9 no.1
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• pp.37-42
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• 2004

In a port fuel injection system of engine, a large part of fuel injected into an intake port adheres on its wall and inlet valve. Consequently, the wall impinging spray interaction might occur the generation of several harmful phenomena. There are uncontrollable mixture formation, an accidental backfire and unburned hydrocarbons. Therefore, it is important to analyze the fuel behavior during the spray-wall interaction. In this study, splash characteristics of impingement and reflecting or scattering behavior of droplets of fuel injected from EFI nozzle were studied experimentally. A test fuel used is LAWS and its physical characteristics are similar to the conventional gasoline except for the ignition point. Since the liquid film formed immediately after impinging on an impingement plate is unstable, it is easy to cause secondary disintegration. In addition, when the intermittently impingement on the impingement plate with LAWS, the splash ratio is around 0.6. If an injection period becomes longer, liquid film will become thick and the splash ratio will fall bout 10 percent. On the other hand, when the injection period of an intermittent spray is long, the same time lapse as a continuous spray is shown.

• Journal of Soil and Groundwater Environment
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• v.9 no.2
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• pp.1-10
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• 2004

The purpose of this study is to evaluate a laboratory test on arsenic reduction efficiency for ARD (Acid Rock Drainage) using limestone and apatite, and to design an apatite drain system. As a result of the laboratory test, results of this study show that pH, arsenic removal ratio, and dissolution amount of limestone ＆ apatite are inversely proportional to flow rates, and apatite removes 100％ of arsenic at 0.6 ml/min/kg flow rate. It is supposed that dissolution rate of apatite is ten times higher than that of limestone. The arsenic compounds are assumed to be Johnbaumnite, and/or Ca-arsenic hydrate. According to the results of the laboratory test, apatite drain system is designed as follow; Sixty two tons of apatite will be needed per one year and six months, and the precipitates will be removed from the precipitation pond per 3 months.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.337-347
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• 1987

Spary and vapor drift injuries of apple, pear, and peach seedling caused by soil-applied oxyfluorfen were studied in a greenhouse. Bud bursting rate of all fruit trees was reduced by both spray and vapor drifts of oxyfluorfen, but reduction in bud bursting rate of pear and peach was greater than that of apple trees. Reduction in the number of leaves per shoot of apple and peach was greater than that of pear trees. Leaf injury of pear was most severe and occurred earliest, but leaves of peach were least injured, Leaf injuries of pear and apple were caused by both spray and vapor drifts, but leaves of peach was injured largely by vapor drift. Reduction in shoot growth of and pear was greater than that of peach trees. Shoot growth of pear was more rapidly retared compared with apple trees. In the field, oxyfluorfen delayed the time of bud bursting in young apple trees. Oxyfluorfen applied between initiation and completion of bud bursting delayed bud bursting more than earlier application although ultimate number of bursted buds was similar to control. The number of leaves per shoot and total length of shoots were lower than control until 40 days after application of oxyfluorfen, and then were similar to control because of vigorous growth after May.

• The Korean Journal of Ecology
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• v.24 no.3
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• pp.131-136
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• 2001

Comparisons of understory vegetation between the burned and the unburned area, and effects of fire on seed germination of Melica onoei, which increased importance value in burned area, were investigated in the black pine forest. The number of plant species in burned and unburned area was 38 and 20, respectively. Melica onoei, indigofera kirilowii, Lespedeza bicolor Miscanthus sinensis were the most abundant species in burned area. A number of seedlings and sprouts of these species were found in burned area. Standing biomass of understory vegetation in burned and unburned area was 88.7g/㎡ and 299.8g/㎡, respectively, in the immediate postfire year. However, standing biomass in burned area increased to 537.2g/㎡ and relative standing biomass of Melica onoei was the highest with a value of 25.7% in the second year Seed germination of Melica onoei in control(C), dark (D), leaf (L), leaf extract (E) treatment was 92.5%, 86.0%, 45.5% and 39.0%, respectively. However, seed germination in L+E and D+L+E treatment was 10.5% and 4.0%, respectively. It is assumed that higher importance value of M. onoei in the postfire vegetation in this study area might be due to the removal of allelopathic inhibitors and the improvement of light condition after fire.