• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.216-219
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• 1987

Dielectric and Mechanical Properties of Mica flake/ Epoxy Composite are investigated. The Mica content is about 50 wt % and its thickness is about $240{\mu}m$. The finished Mica flake/Epoxy Composite contains about 0.1-1.0 wt % of aminosilane coupling agent. Ruby Mica filler and high temperature curing Epoxy resin are used. From the viewpoint of dielectric and mechanical properities. the optimum properties is obtained for the sample post cured at $130^{\circ}C$ for 5 h ours after curing at $80^{\circ}C$ for 2 hours and with 0.5 weight % silane coupling agent.

• Journal of the Korean Ceramic Society
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• v.44 no.9
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• pp.496-501
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• 2007

The properties of the polymer-modified mortars are influenced by the polymer film, cement hydrates and the combined structure between the organic and inorganic phases. Also, this quality of polymer modified cement strongly depend on weather condition. To overcome this problem, polymer-modified cement based on rapid setting cement mortars were prepared by varying polymer/cement mass ratio (P/C) with a constant water/cement mass ratio of 0.5. The effect of polymer on the hydration of this polymer cement is studied on different curing temperature. The results showed that the polymer mortar which is modified with rapid setting cement have superior physical strength properties on independent curing temperature. In addition the PIC ratio, the compressive strength, flexural strength, tensile strength and adhesion strength of mortar is enhances and polymer-modified cement based on rapid setting cement is more beneficial to the improvement of the mortar properties in jobsite.

• Elastomers and Composites
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• v.55 no.1
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• pp.6-12
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• 2020

Poly(ethylene-co-vinyl acetate) compounds and vulcanizates containing dicumyl peroxide (DCP) (HD) were prepared, and the curing agent and reaction products were analyzed using gas chromatography/mass spectrometry (GC/MS). Samples containing trially cyanurate (TAC) and DCP (HDT) were also prepared and analyzed. Some raw DCP were decomposed in the injector region of GC to produce acetophenone. DCP was detected in the HD compound but was not observed in the HD vulcanizate, and instead acetophenone and 2-phenyl-2-propanol were detected. Both DCP and TAC were observed in the HDT compound but not in the HDT vulcanizate, where acetophenone and 2-phenyl-2-propanol were detected. Thus, some of the DCP decomposed during the compounding process. The formation mechanism for acetophenone and 2-phenyl-2-propanol during the crosslinking reaction was identified, and differences in the crosslinking reactions of HD and HDT compounds were discussed.

• Macromolecular Research
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• v.16 no.2
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• pp.128-133
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• 2008

Several dual-curable acrylic pressure-sensitive adhesives (PSA) were synthesized by the radical polymerization of acrylic monomers containing benzophenone, hydroxyl, and alkyl groups. The optimum extent of UV-induced cure was determined by varying the content of the benzophenone groups (the photoinitiator) from 0.5 to 1.5 wt%. The weight average molecular weight of the polymers obtained ranged from 300,000 to 700,000 amu. The coated pressure-sensitive adhesives were cured either by short UV exposure to induce the grafting of acrylic polymers, or by heating for 6 hat $60^{\circ}C$ to promote the reactions between the polyisocyanates and hydroxyl groups. The dual-curing behavior was determined by monitoring both processes quantitatively by infrared spectroscopy. The developed dual-curable acrylic pressure-sensitive adhesives were found to compensate for the limitations in UV-induced curing of thick coatings.

• Computers and Concrete
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• v.10 no.1
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• pp.49-57
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• 2012

Nano-particle-reinforced cement mortars have been the basis of research in recent years and a significant growth is expected in the future. Therefore, optimization and quantification of the effect of processing parameters and mixture ingredients on the performance of cement mortars are quite important. In this work, the effects of nano-silica, water/binder ratio, sand/binder ratio and aging (curing) time on the compressive strength of cement mortars were modeled by means of artificial neural network (ANN). The developed model can be conveniently used as a rough estimate at the stage of mix design in order to produce high quality and economical cement mortars.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.71-72
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• 2020

γ-dicalcium silicate (γ-C2S) is characterized by its strong carbonation reactivity and has the prospect to be utilized as a building material with the added benefit of CO2 capture. This paper aims to point out the impact of γ-C2S on the microstructure characteristics and mechanical properties of GGBFS paste, and mortar samples. Three curing conditions including un-carbonation, natural carbonation, and accelerated carbonation were applied to the research. Besides, hydration products after the carbonation process are also detected. What's more, the carbonation treatment method also meets the requirement of capture more greenhouse gas and recycles the waste products of metallurgy.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.105-110
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• 2006

In order to utilize coal fly ash (hereafter : coal ash ) discharged from coal boiler as a material for civil engineering usage such as snow melter or soil improver, we have to prevent leaching hazardous elements such as fluorine boron and heavy metals from the coal ash because the leaching concentrations of some elements in the ash exceed the Japanese standards for environmental soil quality. Through the laboratory experiments and mill trials we confirmed that the leaching concentrations of fluorine, boron and heavy metals were maintained below their environmental standards by mixing with fixation chemicals and curing for a short time.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.5
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• pp.100-108
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• 1998

Compost stability represents the state of microbiological activity and measurements of respiration either through $CO_2$ evolution or $O_2$ uptake should provide the best indication of this state. Hog manure amended with sawdust was composted in a pilot-scale reactor vessels using continuous and intermittent aeration for 3 weeks. In this study we evaluated the $CO_2$ respiration rate effect of aeration method on the reduction of $CO_2$ evolution, and investigated the stability of fresh and finished compost for plant growth. The intermittently aerated composting is a practical proposition for a very stable compost making. The $CO_2$ respiration rate in the fresh and finished compost during intermittently aerated composting was maintained from 0.3 to 1.4 and was good for use in horticulture, while the continuously aerated composting was 7 to 23 and needed more time for compost curing.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.75-76
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• 2023

In the cement industry, various research initiatives are underway to achieve carbon neutrality. Mineral carbonation is a technology that converts carbon dioxide into minerals for storage, and CO₂ reactive hardening cement is a type of cement that incorporates mineral carbonation technology. In this study, we aimed to manufacture CO₂ reactive hardening cement for reducing carbon emissions in the cement industry by utilizing waste concrete powder generated in the construction sector.

• Current Research on Agriculture and Life Sciences
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• v.18
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• pp.61-69
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• 2000

This study was conducted to investigate most effective the optimum lime content for lime-clay modification. To achieve the aim, characteristics of compaction and compressive strength were tested by adding of 0, 5, 10, 15 and 20% lime (Hydrated lime) of dry weight of the clay. Distilled water was added 10, 15, 20 and 25% of dry weight of lime-clay mixture. In this test, the compressive strength of the specimens was measured according to the following curing period : 7, 21, 28, 35 and 49 days. The results are as follows. (1) As lime additive increased, the optimum moisture content of lime-clay mixture was increased and the maximum dry density was decreased. (2) The soil mixture of 20% of the moisture content and 10% of lime additive was shown the maximum compressive strength. (3) As curing period longer, the compressive strength was increased but after 21 curing days, the increasing rate of compressive strength was low as compared with earlier its value. (4) In the range of 20% of the moisture content, compressive strength of mixture of 10% lime additive increased twice compared with that of mixture of 0% lime additive. (5) All of the lime-clay are possible to use for an sub-base material and 20% of moisture content of lime-clay mixture is possible to use for a base material.