• Korean journal of applied entomology
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• v.59 no.2
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• pp.83-91
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• 2020

We assessed efficacy of spraying pesticides from an unmanned helicopter to control two insect species, Monochamus alternatus and M. saltuarius, which are vectors of pine wood nematodes. Control efficacy of thiacloprid FL (33×), acetamiprid ME (33×), and flupyradifurone SL (33×) was determined by placing caged insects in the canopy of pine trees (Pinus sp). Water-sensitive paper was used to record the spray pattern of pesticide droplets and the degree of coverage; furthermore, we investigated peripheral scattering due to spraying. The three pesticides showed > 96% control efficacy against the targeted vectors, and pesticide droplet spray patterns were similar. Peripheral scattering was observed up to 20 m in front and 10 m to the left, right, and behind the targeted area. The coverage index of all the directions at 5 and 10 m distance was 6-7 and 2, respectively.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.335-336
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• 2000

도시 대기는 복잡한 성분을 가진 입자상 물질로 이루어져 있는데, 검댕 입자나 비산재(fly ash)등과 같이 일차오염물질과 복잡한 대기 화학반응에 의해 생성되는 이차오염물질이 혼재하고 있기 때문이다. 도시 대기 중의 입자상 물질은 대부분 황산염, 질산염, 암모늄염 입자상 물질과 유기 입자들로 구성되어 있는데, 탄소 입자는 도시의 미세 입자 중 거의 반 정도를 차지한다. (Ro et. el., 2000) 본 연구에서는 서울 대기에서의 입자상 물질에 대한 분석을 EPMA(Electron Probe X-ray Microanalysis)를 이용한 단일 입자 분석법(Single Particle Analysis)을 가지고 행하였다. (중략)

• Journal of Korean Society of Environmental Engineers
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• v.38 no.2
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• pp.96-99
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• 2016

This study characterized fly ash produced from a sewage sludge incineration facility in Korea to determine if the byproducts can be utilized. All the incinerated sewage sludge was from a city in Korea. To characterize fly ash and to determine if it can be utilized, pH, water contents, elemental components, particle size, surface morphology, heavy metal compositions, and others were analyzed. In average, pH was 6.2, and water contents was about 5%. T-N and $T-P_2O_5$ were 3% and 24.5%, respectively. Particle size averaged 836 nm; surface morphology did not exhibit any significant results. X-ray diffraction (XRD) analysis results revealed that major components of the fly ash were $P_2O_5$, CaO, MgO, $K_2O$. Composition of heavy metals by the Korea Standard Methods for Waste Quality did not exceed the criteria for specified wastes in Korea.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.10
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• pp.574-579
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• 2016

This study assessed feasibility of making granular fertilizer with fly ash from a sewage sludge incinerator in Korea. Composition, characteristics, strength, and heavy metal contents of the granular fertilizers were investigated. Due to its high contents of phosphorus, fly ash from a sewage sludge incinerator could be used to make fertilizers. Granulation rates (2-4 mm granules) over 80% could be achieved as the fly ash contents were 15% or less of the fertilizer. Leaching tests of the fertilizers, based upon the Korean Standard Methods for Solid Wastes, showed the concentrations of heavy metals less than the risk limits. However, contents analysis of the fertilizers, based upon the Korean Standard Methods for Soils, experienced higher levels of heavy metals than the risk limits as the fly ash content exceeded 7% of the fertilizer. Thus, the fly ash needs to be added less than 7% of the fertilizer if there is no pretreatment to remove heavy metals.

• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.295-298
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• 2008

In the reactor for the american standard test method (ASTM) D5757-95 with swirl injection nozzles, the attrition characteristics of sand was investigated. The change of particle size distribution and weight of fine particles were compared to identify the effect of swirl injection nozzle on attrition. The fine particles due to particle attrition increased with increasing gas velocities. The weight of fine particles due to jet attrition was changed with angle of swirl injection nozzle. The fine particles decreased with decreasing the angle of swirl injection nozzle. Also, the change of particle size distribution increased with increasing the number of swirl injection nozzles at the same flow rate.

• Journal of Energy Engineering
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• v.9 no.4
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• pp.348-357
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• 2000

본 연구에서는 동해화력 순환유동층 보일러와 유사한 3개의 사이클론을 갖는 직사각형 구조의 순환유동층 반응기를 이용하여 동해화력 운전조건 -연소로 공기 속도, 일-이차 공기비, 전체 고체량(inventory), 입도 및 입도분포 등- 에 따른 축방향 고체 체류량 및 순환량 등의 수력학적 특성을 고찰하였다. 상승관에서의 공기유속(U$_{0}$)이 증가함에 따라, 또는 PA/[PA+SA]비가 증가함에 따라, 그리고 전체 고체량(inventory)이 증가함에 따라 고채 채류량 및 순환량은 증가하는 것으로 나타났다. 또한 넓은 입도 분포를 갖는 석탄 회재의 경우는 균일한 입도 분포의 입자들에 비해 입자 비산량 및 고체 순환량이 작을 것으로 나타났다. 한편, 층내에서의 고체 체루량 분포를 감소지수 a 및 K를 사용하여 나타낼 수 있었으며, a 및 K와 유속 및 입자간의 상관 특성치를 도출하여 유동 및 순환특성을 고찰하였다. 상기의 상관수는 균일한 입도의 모래에 비해 석탄회재가 비교적 큰 값을 나타내었으며, 상관수가 클수록 희박상 영역에서의 비산 및 고체 순환량이 작은 것으로 나타났다.다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.320-321
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• 2002

가상임펙터(virtual impactor)는 충돌판을 가지고 있는 관성임팩터(inertial impactor)와는 다르게 분리입경보다 큰 입자를 분리할 수 있는 부 유동과 분리입경보다 작은 입자를 분리할 수 있는 주 유동으로 나누어져서 입자의 튀김(bouncing)이나 재비산(reentrainment) 없이 입자를 분리 또는 농축할 수 있다. 하지만 관성임팩터처럼 여러 단을 연결하여 작은 입자를 분리할 수 없기 때문에 주로 큰 입자의 분리 및 농축에 쓰여왔다. (중략)

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.11a
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• pp.101-104
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• 2000

1980년대 중반이후 화력발전소용으로 순환유동층 연소로(Circulating fluidized bed combustor : CFBC)가 많이 건설되고 있다. 이는 기존의 고정층 연소로보다 효율면에서 좋고, 차지하는 부피는 훨씬 적기 때문이다. 순환유동층의 층물질로 사용되는 모래, 석탄회, 석회석 등은 순환하는 입도, 비산유출되는 회재(fly ash)와 하부로 배출되는 회재(bottom ash)로 나누어진다. 주입되는 석탄 및 석회석의 입도는 입자-입자, 입자-연소로의 마모(attrition), 입자의 깨짐(fragmentation), 입자의 축소(shrinking) 등에 의해서 변화하게 된다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1998.10a
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• pp.73-75
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• 1998

• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.147-163
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• 2015

Chemical and mineralogical properties of coal ash samples from the nine thermal power plants of Korea were investigated to acquire basic data for estimating the potential of rare metal recovery. Chemical compositions of coal ash were consistent with those of average shale and foreign coal ashes. However, there were small differences between the metal contents of domestic anthracitic and imported bituminous coal ashes. Unburned coal particles were much abundant in the ash of domestic anthracitic coal. Chalcophile elements were relatively enriched in the fly ash compared to bottom ash. Silicate glass was the major component of coal ash with minor minerals such as quartz, illite (muscovite), mullite, magnetite, lime, and anhydrite. Al and Si were the major components of the glass with varying contents of Ca, Fe, K, and Mg. Glass occurred in a form of porous sphere and irregular pumace-like grain often fused with iron oxide spheres or other glass grains. Iron oxide spheres were fine intergrowth of fast-grown iron oxide crystals in the matrix of silicate glass. Chemical, microstructural, and mineralogical properties would guide successful rare metal recovery from coal ash.