• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.489-492
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• 2006

Needs for the new technologies and cutting-edge Ultra Flowing Self-Compacting Concrete are emerging as the concrete structures are becoming bigger and more specialized recently. In North America and Europe, SCC, which has high resistance against flow ability and segregation, is being used as concrete material in applications such as precast and prestressed bridges, where reinforcing bars are overcrowdedly placed. In Korea, SCC has been utilized limitedly in building structures but its utilization should be expanded to engineering structures such as bridges. In this study, for the application in precast and prestressed bridges with overlycrowded reinforcing bars, USCC was mixed with admixtures to give a binary system and a ternary system according to the 1st grade rules by JSCE (Japan Society of Civil Engineers). Compressive strength and splitting tensile strength of the resulting USCCs were tested. Elastic modulus were compared with the values suggested in CEB-FIP code and ACI 318-05.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.33-34
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• 2013

Recently, as the policy of state that it is the low carbon green growth is promoted, the effort for reducing the CO₂ gas generation ejected from the construction industry in the cement production is continued. That is, the method using the mineral admixtures including the silica fume and red mud, silica fume and etc. it is the industrial byproduct with the method solving the exhaustion problem of the environmental contamination settlement and natural resources, the great quantity as the cement substitute material is examined. Accordingly, in this research, the strength characteristic of the curing body differentiating the curing method of the ternary system inorganic binder using the blast furnace slag and red mud, silica fume and etc. as the cement substitute material tried to be examined.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.179-180
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• 2020

CO2 emissions are caused by cement manufacturing process. To solve this problem construction industry are using industrial by-products to replace cement. In this study, three different industrial by products were used and mixed with hybrid fibers to enhance bond strength. As the result, Regardless of the mixing rate of silica fume, the compressive strength of the ternary non cent mortar was higher than that of OPC and binary. And mixed hybrid fibers cured by room temperature compressive strength were 23% higher than those without hybrid fibers.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.1
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• pp.10-18
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• 2014

This study carried out to evaluate the hydration heat analysis and fundamental characteristics such as air content, slump, compressive strength and dry shrinkage according to concrete with premixed cement, ternary concrete and OPC concrete for using concrete with premixed cement. The results of experiment are founded that concrete with premixed cement have sufficient performances such as workability, compressive strength and dry shrinkage. Also, the results of hydration heat analysis are founded that concrete with premixed cement have more performance than ternary concrete and OPC concrete at a point of view for the quality control such as thermal crack reducing and economic benefit. Therefore, it is desirable that concrete with premixed cement should be used to rise durability performance and convenience of maintenance.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.204-211
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• 2018

In this study, densities of water + N-Methyldiethanolamine (MDEA), Water + 2-Amino-2-Methyl-1-Propanol (AMP), MDEA + AMP binary systems and Water+MDEA+AMP ternary system were measured over the full range of composition at temperatures from 303.15 K to 333.15 K by using an Anton Paar digital vibrating tube densimeter (DMA4500). The experimental excess volumes have been obtained from the experimental density results and have been fitted using the Redlich-Kister-Muggianu expression. The parameters obtained from the binary excess volume data were used for the correlation of ternary system with one additional ternary parameter for each isotherm. All investigated binary and ternary systems are completely miscible, because the values of excess volume are negative under the examined conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.390-395
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• 2011

In order to develope piezoelectric transformer for the ballast of fluorescent lamp, the composition of piezoelectric ceramics was 0.95Pb($Zr_xTi_{1-x}$)O3+yPb($Mn_{1/3}Nb_{2/3}$)$O_3$+(0.05-y)Pb($Sb_{1/2}Nb_{1/2}$)$O_3$. PMN compound was selected to improve mechanical quality factor and PSN to prevent the decrease of dielectric constant and electromechanical coupling coefficient. Dielectric and piezoelectric characteristics in the region of MPB of 0.95Pb($Zr_xTi_{1-x}$)$O_3$+yPb($Mn_{1/3}Nb_{2/3}$)$O_3$+(0.05-y)Pb($Sb_{1/2}Nb_{1/2}$)$O_3$ ceramics was discussed both quantatively and qualitatively.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.137-140
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• 2017

Agricultural pests, diamondback moth (Plutella xylostella), green peach aphid (Myzus persicae) and two-spotted spider mite (Teyranychus urticae), are becoming major pests in human dwellings in a variety of ways across the world. For management of these pests, the essential oils of Coriandrum sativum and Cinnamomum cassia prepared by steam distillation, hexane extraction and supercritical extraction methods were evaluated for the insecticidal effects. Using the contact bioassay, the $LD_{50}$ value of C. sativum oil by steam distillation extraction method was $30.59{\mu}g/cm^2$ against M. persicae adults. The $LD_{50}$ values of C. cassia oils prepared by steam distillation and hexane extraction methods were 5.96 and $4.64{\mu}g/cm^2$, respectively, against T. urticae adults, and $LD_{50}$ value of the essential oil by supercritical extraction method was $6.50{\mu}g/cm^2$ against M. persicae adults. This study showed that C. sativum and C. cassia oils could be an effective natural acaricide and insecticide against agricultural pests.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.848-851
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• 2009

석탄슬래그는 회분의 조성에 따라 고온에서 매우 상이한 슬래그 거동을 보여준다. 국내 가스화 대상탄으로 검토된 탄 중, 산성 산화물의 함량이 높아 고용융점을 갖는 7종의 석탄 회분을 가스화 조건인 고온, 환원분위기에서 점도 측정을 실시하였다. 4종의 탄에 대해서는 높은 점도를 낮추기 위하여 염기성 산화물인 CaO를 3가지 비율로 혼합하여 점도 측정을 실시하였다. 또한, flux의 혼합으로 인해 발생할 수 있는 결정체 형성을 FactSage 평형계산 프로그램과 CaO-SiO2-Al2O3 3성분계 상평형도를 이용하여 예측하였다. CaO가 첨가된 시료 모두에서 낮은 CaO 첨가비에서는 원래의 시료보다 낮은 점도를 보였으나, CaO첨가비가 20% 이상일 때는 anorthite이 형성되어 $T_{cv}$를 갖는 결정슬래그로 점도 거동이 변화하면서 실제조업 가능한 온도를 증가시켰다. 점도 측정 후 냉각된 시료의 SEM/EDX 분석을 통해 형성된 결정체를 관찰한 결과, FactSage와 상평형도에서 예측된 결정체와 유사하게 나타나 CaO-SiO2-Al2O3 3성분계 상평형도가 결정체 예측에 유용함을 확인하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.6
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• pp.217-221
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• 2005

The evaporation amounts of volatile Cd, Pb and Zn were characterized by measuring their total concentrations in the EAF dust-clay bodies with various mixing ratio and heat treatment temperature. TCLP test was conducted for evaluating the chemical stabilities of the heavy metal elements. Evaporation amounts and leaching concentrations of heavy metal components were strongly dependent on the mixing ratio and heat treatment temperature. The evaporation of the heavy metal components in EAF dust was effectively suppressed by increasing the clay content. The leaching concentrations of heavy metal components were decreased with increasing clay content and temperature. 20 wt% EAF dust-80 wt% clay sample shows nearly zero evaporation and leaching concentrations of heavy metal components. XRD analysis showed that peak intensities of major crystalline phases such as franklinite and quartz were decreased with increasing the heat treatment temperature which means that the stabilization mechanism of the heavy metals was related with the vitrification process of the $SiO_2$ in the clay.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.617-623
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• 1997

In this study, the mechanism on the phase behavior of polysorbate nonionic surfactants was investigated. In the ternary system containing water, hexanol as a polar oil and surfactant, the phase behaviors ranging from micellar region to occurrence of liquid crystal phase were observed by crossed microscope. As results, fine mosaic texture of liquid crystal phase and other phases were examined in the range of 20~70 wt%. This range if thought to give information about the basic data for the formulation of more stable emulsifying systems or dispersed systems. According to the alkyl chain length, three phase region diminished, whereas two phase range increased without an observation of the anisotropic liquid crystalline phase.