• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.31-32
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• 2022

Unlike conventional building materials, the living building material (LBM) cube is composed of sand, gelatin, and cyanobacteria without cement. The surface of the LBM cube absorbs CO2 from the atmosphere by photosynthesis and is deposited in the form of CaCO3. In addition, the crystals generated in this process strengthened the gelatin-sand structure to enhance the compressive strength.

• Magazine of the Korea Concrete Institute
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• v.28 no.4
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• pp.10-14
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• 2016

• Journal of Energy Engineering
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• v.27 no.2
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• pp.55-60
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• 2018

In this study investigated the Controlled Low Strength Materials using coal ash and steel slag(KR slag) as the main material in the thermal power plant classified as waste resource. Bottom ash and KR slag are mixed at a ratio of 7: 3 to expand the use of industrial by-products through carbonate($CO_2$-fixation) reactions and inhibit the exudation of heavy metals. The results showed that the water content increased as the content of bottom ash increased. It was confirmed that as the powder content increased, the bleeding ratio decreased. Also, as the content of one kind of ordinary portland cement (OPC) decreased, activation of hydration reaction decreased and compressive strength decreased. However, when the mixed composition is appropriately adjusted, the compressive strength of 2.0 MPa required for the controlled low-strength material can be satisfied.

• Journal of the Korean Magnetics Society
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• v.26 no.2
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• pp.50-54
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• 2016

We analyzed the angular dependence of ferromagnetic resonance linewidth in exchange coupled CoFe/MnIr bilayers. The maximum and minimum linewidth was observed in the easy and hard direction of unidirectional anisotropy by exchange coupling, respectively, and it was well agreed with the angular dependence of exchange bias field. The maximum linewidth was due to the twist of CoFe magnetization near CoFe/MnIr interface from direction of pinned MnIr spin to direction of applied magnetic field. While, minimum linewidth more higher than that of CoFe was related to rotatable anisotropy field, and explained by easy axis distribution of MnIr grains.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.47-48
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• 2016

Mineral carbonation technology is a process whereby CO₂ is chemically reacted with calcium-and/or magnesium-containing minerals to form stable carbonate materials. Add the Materials that could fix CO₂ as mineral admixture to concrete can improve the anti-carbonation properties of concrete. This paper has carried on the literature research on the carbonated mechanism of Material that could fix carbon dioxide. Such as Brucite, 𝜞-C₂S, Mg₂SiO₄, MgO, Ca₃MgSi₂O₈. And summarizes the development of the development of this field.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.203-210
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• 2018

Corrosion of the rebar is one of the main factors affecting the durability of reinforced concrete in the world which lead to the failure of the reinforced concrete structures. In this research, a new method of fixing $CO_2$ is practiced to improve the carbonation resistance of the concrete. Brucite($Mg(OH)_2$), a kind of common $CO_2$ fixation materials, was added into ordinary Portland cement paste. Samples containing 0%, 5%, 10%, and 15% $Mg(OH)_2$ were exposed to an accelerated carbonation curing regime with 20% concentration of $CO_2$, 60% relative humidity, and a temperature of $20^{\circ}C$ until tested at 3d, 7d, 14d and 28d. After 28d of $CO_2$ accelerated curing, in the paste containing $Mg(OH)_2$, magnesian calcite was detected by SEM-EDX. Meanwhile, the paste containing $Mg(OH)_2$ exhibit the better pore distribution than ordinary Portland cement paste and the compressive strength of the cement paste containing $Mg(OH)_2$ were more than 50Mpa.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.85-95
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• 2001

The purpose of this study was to evaluate the material for fixed type retainer, allowing physiologic tooth movement. and proper remodeling or periodontal tissue during retention period. The Present study was Performed to observe the histologic changes of periodontal tissue after application of different types of fixed type retainer after orthodontic tooth movement in young adult dogs. For this study, 4 young adult dogs were used as a experimental animal and experimental group was divided into three groups : experimental group 1 contained right side maxillayy third incisors and canines, experimental group 2 contained contralateral teeth of same animals, and control group contained mandibular premolars. And each dogs were applied the 4 different types of fixed type retainer to experimental group 1. The experimental teeth were ligated on the Sentalloy closed coil $spring^{\circledR}$(Tomy Co., Japan) from maxillary third incisors and canines and applied orthodontic force at initial 200gm-forced during 1 week. All the experimental animals were sacrificed on the 3rd week after the orthodontic teeth movement and then the specimens were taken, fixed in formalin, embeded in parafin, sectioned $6-8{\mu}m$ in thickness and stained with Hematoxylin-Eosin staining, and Masson's trichrome staining method. Examined under the light microscopy The following results were observed. 1. There were observed that decreased infiltration of giant tells in pressure side and increased the new bone forming in tension side on the specimen of 6-stranded 0.0195' $Respond^{\circledR}$(G&H Co., U.S.A.) group. Periodontal ligament fibers were much compressed or elongated in 3-stranded 0.018', 0.020' $Dentaflex^{\circledR}$(Dentarum Co., Germany), and Superbond $C&B^{\circledR}$(Sun Medical Co., Japan) groups. 2. In experimental group 1, necrotic bone inside the alveolar bone of pressure side, forming of the sharpey's fiber in osteoid tissue, and remodeling of the periodontal ligament were observed in all animals. 3. In experimental group 2, it was observed that the amount of bone resorption was equal or decreased in pressure side, and increased new bone forming and significantly decreased infiltration of giant cell than the experimental group 1. By this results, it considered that 6-stranded $Respond^{\circledR}$(G&H Co., U.S.A.) wire was the most useful material allowing early periodontal tissue remodeling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.165-166
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• 2017

Corrosion of reinforcement is the main factors affecting the durability of reinforced concrete in the world which lead to the failure of structures of reinforced concrete buildings. In this research, mixed brucite(Mg(OH)₂) into ordinary portland cement paste in ratio of 5, 10 and 15% as a kind of CO₂ fixation material. Samples were exposed to an accelerated carbonation enslavement of 20% CO₂ concentration, 60% relative humidity, and a temperature of 20℃ until tested at 3d, 7d, 14d and 28d. After 28d CO₂ accelerated curing, in the paste containing MH megnesian calcite was found by XRD and SEM-EDX. Meanwhile, paste containing Mg(OH)₂ exhibit the better pore distribution than ordinary portland cement paste and relatively good compressive strength.

• Resources Recycling
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• v.30 no.1
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• pp.77-82
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• 2021

Reduction of CO2 emissions is an important issue in the steel industry, and the research on carbon materials that can partially replace cokes is necessary to reduce CO2 emissions. Meanwhile, the biomass fuel contains some fixed carbon, and the carbon content in the biomass can be increased by torrefaction. As one of the biomass fuels, coffee grounds contains about 55 mass% of carbon, and its about 270,000 tons are landfilled and incinerated annually in Korea. In addition, research on the recycling process due to the increase in annual coffee consumption is required. In this study, the effect of temperature on the concentration of fixed carbon in coffee grounds was investigated during torrefaction. Moreover, the effects of mixing ratio of torrefied coffee grounds with cokes on the carbon concentration and dissolution efficiency in the metal sample were investigated.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.157-166
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• 2017

In general, carbonation and chlorine ions are the most harmful causes of deterioration of concrete structures. Recently, a method has been developed to control the corrosion of rebar in concrete containing chloride by impregnating a Surface coating material with a inhibitor. In this study, accelerated carbonation and differential thermogravimetric analysis (TG-DTA) and CASS tests were carried out to evaluate the characteristics of Surface coatings containing Organic Corrosion inhibitors which are excellent in corrosion inhibition and fix degradation causes $CO_2$ and $Cl^-$. As a result of the experiment, TG-DTA analysis and accelerated carbonation showed that $CO_2$ was directly reacted with amine derivative in concrete by the incorporation of Organic Corrosion inhibitor. In other words, $CO_2$ was immobilized and carbonation inhibition effect was confirmed. In addition, in the CASS test, the specimen coated with the Surface coating material containing the Organic Corrosion inhibitor with $Cl^-$ fixing property showed no corrosion until the 28th day and had excellent performance in preventing corrosion of a rebar by the chloride ion.