• 대한의생명과학회지
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• 제26권3호
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• pp.217-225
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• 2020

Scuttle fly which moves abruptly after standing for a while and stop suddenly to rush off again, is a fly species in the Phoridae family. This species like rotten organic materials and it is known to proliferate even in the industrial materials including organic solvents. These characteristic behaviors of the scuttle fly seem to be related to muscular and nervous system or neurotransmitters. Thus, we focused at the neurotransmitter, corazonin (Crz) that is known to be related to resistance to stress and investigated the developmental process of the neurons in the scuttle fly. Corazonin is a neuropeptide being expressed in the central nervous system (CNS) and is known to control mainly physiological functions and behaviors. Its many functions that have been proposed are still in controversy. In this studies, we found that there are three groups of corazoninergic neurons in the larval CNS of the scuttle fly and these neurons undergo distinguishable changes through metamorphic process compared to different fly species. Larva has 3 pairs of Crz neurons at the dorsolateral area of the brain, 1 pair at the dorsomedial brain and 8 pairs at the ventral nerve cord.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.125-130
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• 1990

Fly Ash in concrete is known to be effective in improving workability, the reduction of heat of hydration, increasing the long-term compressive strength, and improving durability. Recently, fly ash is consedered an essential material for the high-strength concrete. In this paper, investigations for the strength and workability characteristics was carried out when fly ash was used in the high-strength concrete. As the result, fly ash was effective in increasing the long-term compressive strength, but the short-term compressive strength was gradually decreased with increating fly ash contents. And also the use of superplasticzers was required for providing the proper workability when fly ash contents were increased. The optimum content of fly ash was about 10%.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2001년도 학술논문발표회
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• pp.82-87
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• 2001

The purpose of this study is for the active use of the fly ash, which is a by-product of the combustion pulverizes coal thermal power plants, to compensate for the lack of landfill and for conservation of energy, by using fly ash as the supplementary cementitious material, and to prove its possibility as the related products of the cement. First of all, the ordinary fly ash is grinded in a special method and its fineness is controlled from 6000$\textrm{cm}^2$/g to 8000$\textrm{cm}^2$/g, then replaced it with the 10% to 80% of the cement mortar in order to test physics characteristics. The first experiment conducts on the strength development in fly ash replacing content and fineness. and the changes of the flow values, incorporating fly ash into cement. The second one is about the slow development of the strength of the fly ash mortar in early ages, and improves its strength with the activator $Na_{2}SO_{4}$, using high volume fly ash.

• 한국토양비료학회지
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• 제28권4호
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• pp.334-339
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• 1995

석탄회의 농업적 활용 방안을 모색하기 위하여 포트에 수수를 재배하였다. 토양은 무연탄회와 유연탄회로 각각 0, 6, 12, 18, 24% 처리되었다. 생육시기중 초장과 줄기의 마디수는 무처리 보다 석탄회처리에서 그리고, 무연탄회보다 유연탄회처리에서 효과가 더 좋았다. 석탄회처리는 24%까지 수수의 생육에 좋은 영향을 미쳤다. 성숙기의 고엽화(枯葉化)율은 석탄회처리에서 현저히 심하였고 석탄회의 농도가 증가할수록 그 율이 증대되었다. 줄기와 잎을 포함한 전수확량은 무처리보다 석탄회처리에서 그리고, 무연탄회보다 유연탄회처리에서 더 높았다. 알곡수량은 무처리보다 석탄회처리에서 그리고, 무연탄회보다 유연탄회처리에서 효과가 더 좋았다. 일반적으로 석탄회처리는 12%까지 수량이 증가되었다. 수수 생육은 pH가 높은 토양에서 왕성하므로 유연탄회 처리는 권장될 수 있다.

• 한국연초학회지
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• 제20권1호
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• pp.5-12
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• 1998

Pot experiment was conducted to investigate the effects of fly ash on growth responses and on accumulation of the heavy metals in soil. Two kinds of fly ash, anthracite and bituminous coal, were treated with different levels of 0, 0.4, 0.8, and 1.2 kg/pot(20L). Tobacco growth was better by application of fly ash than that by the control. However, the early stage of growth by application of bituminous coal, 1.2 kg/pot, was decreased due to the boron toxicity occurred by fly ash. Generally, tobacco yield was significantly increased with applying fly ash, showing the highest yield at 1.2 kg/pot for anthracite and at 0.8 kg/pot for bituminous coal. The content of total nitrogen in leaves was higher with fly ash than that of the control, while the content of calcium in leaves was low, Contents of heavy metal and the other minerals were not significantly different between the control and the treatment of fly ash. Soil pH after experiment was linearly increased with application level of fly ash, indicating that the application of bituminous coal was more effective than that of anthracite. Contents of available phosphate, exchangeable $Ca^{2+}$+ and $Mg^{2+}$ in soil were increased by application of fly ash, especially with bituminous coal. Contents of Cu, Cr, and Ni were increased with application level of bituminous coati even if the contents were still lower than critical levels for farming land. The other heavy metals were similar between the control and the application of fly ash.

• 한국재료학회지
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• 제27권2호
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• pp.76-81
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• 2017

Recently, there have been many efforts to establish suitable processes for recycling fly ash, which is produced in thermal power plants and which poses serious environmental problems. Use of fly ash as a major ingredient of ceramic tiles can increase fly ash utilization, as well as reduce the cost of raw materials in ceramic tile production. In this study, the effects of fly ash addition on ceramic tile properties such as bending strength, water absorption and porosity were investigated. A manufacturing process of ceramic tile was developed for utilization of fly ash with high carbon content. In this approach, it is important to hold the ceramic tiles at a temperature that is sufficient for carbon oxidation, before the pores supplying oxygen to the inside of the ceramic tile are sealed. Ceramic wall tiles were manufactured with 0-40wt% of fly ash addition. The water absorption and porosity of the fired body were slightly changed with increasing fly ash content up to 30wt% and decreased with greater amounts of fly ash addition. The bending strength of ceramic tile including 10wt% fly ash increased, reaching a level comparable to that of ceramic tile without fly ash.

• 한국세라믹학회지
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• 제39권12호
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• pp.1164-1170
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• 2002

고령토질 벽돌에 대한 fly ash의 첨가가 소결온도에 미치는 영향과 그에 따른 물성의 변화를 관찰하였다. Fly ash로는 탄소 8∼9%의 무연탄 연로 재를 사용하였고 고령토 등의 국산 천연원료를 이용하여 실험을 하였다. Fly ash와 고령토 등의 4종의 원료를 5가지의 혼합비로 조합하여 혼합, 성형하고 각각 1050${\circ}C$, 1100${\circ}C$, 1150${\circ}C$, 1200${\circ}C$의 온도로 소성하였다. 소성온도가 증가함에 따라 모든 시편에서 흡수율은 낮아지고 압축 강도는 증가하였다. 소성온도가 1100${\circ}C$ 이하인 경우 fly ash의 함량이 증가함에 따라 흡수율은 증가하고 강도가 감소하였다. 이에 비하여 소성온도가 1150${\circ}C$ 이상인 경우 흡수율은 소성온도가 낮은 경우와 유사한 경향을 보였으나 강도는 증가하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제3권2호
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• pp.191-198
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• 1999

The purpose of this study is investigating characteristics of the concrete containing Fly-ash according to different 4 mix design, that is, the first mix design is partial replace Fly-ash of cement, second is partial replace Fly-ash of cement and fine aggregate, third is partial replace Fly-ash of fine aggregate, fourth partial replacement of fine and coarse aggregate. For this purpose, selected test variables were water-binder ratio with two levels of 45%, 50%, and Fly-ash contents with four levels 0%, 10%, 20%, 30%, As the result of this study are as follow. 1) The result of mix design of a partial replacement of cement, the slump-flow value was appeared a promotive effect of viscosity. But in case of the over with Fly-ash 10% and the other mix design was not changed slump value. 2) The unit weight of the mixing rate with Fly-ash 0% was $1.875{\sim}1.884t/m^3$, the other mix design 10% over with Fly-ash was $1.846{\sim}1.615t/m^3$, the difference was appeared less about 15% than that. 3) In design, partial replace Fly-ash of fine aggregate, this compressive strength was appeared that the concrete age after 7 days was higher than in partial replacement of cement, therefore, the default of a concrete with Fly-ash, that is the earlier compressive strength was to lessen, was improved. 4) The thermal conductivity of the all mix design was $0.447{\sim}1.144kcal/mh^{\circ}C$, this value was as good as a lightweight aggregate concrete.

• 대한토목학회논문집
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• 제26권1A호
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• pp.205-211
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• 2006

본 연구에서는 플라이애쉬 혼입률에 따른 라텍스개질 콘크리트의 역학적 특성과 내구성을 평가하였다. 이를 위해 라텍스 혼입률 변화(0%, 10%, 15%)와 플라이애쉬 혼입률 변화(0%, 10%, 20%, 30%)를 주 실험변수로 하여 평가하였다. LMC와 FA-LMC의 특성분석을 위하여 압축강도, 휨강도 그리고 황산 및 염산에 의한 내약품성 시험을 실시하였다. 실험결과, 플라이애쉬를 혼입한 라텍스 개질 콘크리트에 있어서, 플라이애쉬 혼입률이 증가함에 따라 공기량은 감소하는 것으로 나타났다. 그리고 FA-LMC의 압축 및 휨강도는 라텍스 개질 콘크리트(LMC)와 유사한 강도발현 특성을 보이며, 장기재령에 있어서는 FA-LMC가 LMC에 비해 높은 휨강도 발현특성을 보였다. 그리고 투수특성에 있어서 플라이애쉬의 혼입률이 증가할수록 투수저항성이 증가하였으며, 내화학약품성에 대한 저항성도 증진되는 것으로 나타났다. 따라서, 플라이애쉬는 LMC의 혼화재로서 투수저항성을 증진시킬 목적으로 효과적으로 사용될 수 있을 것이다.

• 한국세라믹학회지
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• 제39권2호
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• pp.126-134
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• 2002

Mechanochemical Processing(MP)을 거친 Cement(MPC) 또는 Fly Ash(MPFA)를 사용하여 fly ash 다량 혼화 고강도 mortar의 제조를 위한 연구를 수행하였다. 단순 ball milling processing를 거친 cement(Ball-mill Processed Cement, BPC)와 채취 그대로의 처리하지 않은 fly ash(As Received Fly Ash, ARFA) 혼화시의 공시체와 비교하여 동일한 fly ash의 혼화량(10, 20, 30 wt%), 동일한 재령(7일 및 28일)의 압축강도 및 미세구조의 관점에서 고찰하였다. MPC와 ARFA 및 BPC와 MPFA를 사용한 mortar 공시체가 BPC와 ARFA를 사용한 것보다 각각 5-11% 및 10-20% 상승한 압축강도 값을 나타내었다. 더욱이 MPC와 MPFA의 동시 혼화 mortar 공시체의 압축강도가 fly ash 혼화량 20 wt% 공시체에서 강도 상승률 24%를 나타내었는데 이 값은 MPC 사용에 의한 강도 향상 비율(8%)과 MPFA 혼화에 의한 강도 향상 비율(12%)의 합을 상회하는 synergy 효과를 나다내는 강도 향상율을 나타냈다. 상기의 강도 증진은 MP에 있어서 fly ash와 cement 입자가 혼합되면서 기계적 에너지가 공급되므로 각 입자의 서로에 대한 친화성이 증대되며, 이로 인하여 수화물 생성시 cement와 fly ash 입자간의 결합력이 더욱 증가하게 되어 압축강도가 증가하는 것으로 고려된다.