• Textile Coloration and Finishing
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• v.33 no.1
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• pp.10-23
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• 2021

In order to synthesize the dye suitable for supercritical carbon dioxide(ScCO2) dyeing, a series of azo based disperse dyes were prepared using various aniline derivatives as diazo components and indol derivatives as coupling components. Dyeing process in ScCO2 of the synthesized dyes was performed on PET fiber at 120℃ for 2 hrs under 250bar pressure with 0.5% o.w.f. of dye concentration. The absorption maxima varied from 400 to 580nm depending on the substituted groups in aniline derivatives and the indol derivatives. The dyes showed high molar extinction coefficients(ε) of 27,000~61,000M-1cm-1. Dyed PET fiber exhibited excellent brightness and good light, washing and perspiration(acid/alkali) fastness properties.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.489-497
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• 2022

In this study, the fluidity, mechanical properties and microstructure of cement pastes with carbon nanotube (CNT) were experimentally investigated. The 6 types of cement paste mixes with different PCE:CNT and w/b had been manufactured, and several tests including flow, compressive strength, absorption and water porosity were performed on cement pastes with or without CNT.Additionally, microstructural observations such as x-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out to examine hydrates formed in cement paste with CNT. As a result, it was found that the performance of cement pastes with CNT was better compared to that of control cement paste (OPC) due to both of hydration acceleration effect and filling effect. Furthermore, the SEM images clearly showed that CNT can bridge cracks formed in cement matrix. Conclusively, it is believed that the CNT, if mixed appropriately, could be an option as nono-materials to improve performance of concrete structures.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.299-306
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• 2023

Environmental pollution problems are occurring due to the negative treatment of basalt waste in Jeju Island. This study identifies the characteristics of permeable block with basalt with physical and chemical adsorption mechanisms and examines their applicability and functionality as building materials. This experiment is basic data for evaluating the functionality of the permeable block by analyzing flexural strength, compressive strength, permeability coefficient, carbon dioxide, and fine dust adsorption rate by producing a permeable block using a basalt waste rock. As the basalt waste stone replacement rate increased, the flexural strength and compressive strength tended to decrease, and as the replacement rate increased, the water permeability coefficient, absorption rate, carbon dioxide, and fine dust adsorption rate tended to increase. Therefore, it is judged that the permeable block using the basalt waste rock is superior to the existing permeable block.

• New & Renewable Energy
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• v.20 no.1
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• pp.135-144
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• 2024

The present study investigated waste medium from a domestic shiitake mushroom farm, which was pyrolyzed to produce biochar. The yield rate of the biochar was compared after exposure to various pyrolysis temperature conditions, and the characteristics of the produced biochar were analyzed. The present study focused on the carbon dioxide (CO₂) adsorption capacity of the resulting biochar. The CO₂ adsorption capacity exhibited a correlation with the pyrolysis temperature of the biochar, with increasing temperatures resulting in higher CO₂ adsorption capacities. Brunauer-Emmett-Teller (BET) analysis showed that the CO₂ adsorption capacity was related to the surface area and pore volume of the biochar. Calcium is added to the process of producing mushroom medium. Experiments were performed to investigate the CO₂ adsorption capacity of the biochar from the waste medium with the addition of calcium. In addition, CO₂ adsorption experiments were conducted after the pyrolysis of kenaf biochar with the addition of calcium. The results of these experiments show that calcium affected the CO₂ adsorption capacity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.1
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• pp.48-53
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• 2009

The effect of bloating and fluxing agent on the microstructure and physical properties were studied in manufacturing the artificial lightweight aggregates of bulk density below] using clay and stone sludge. In case of the aggregates added only with bloating agent, the bulk density and water absorption were $0.5{\sim}1.0$ and $41{\sim}110%$ respectively but the microstucture was not uniform with a rough appearance. For the aggregates added with a fluxing agent and one bloating agent, a part of shell was lost due to explosion of specimen caused by over-bloating during a sintering. The mixed addition of bloating agents with vacuum oil, carbon and ${Fe_2}{O_3}$ made the microstructure homogeneous by generating an uniform black core and shell structure. The aggregates added with mixed agents and sintered at $1200^{\circ}C$ showed the bulk density 67 % lower and water absorption 48 times higher than those of the specimen with no additives. ]n this study, the artificial lightweight aggregates showing the bulk density of $0.5{\sim}1.0$ and water absorption of $50{\sim}125%$ could be fabricated to apply to various fields.

• Clean Technology
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• v.20 no.2
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• pp.146-153
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• 2014

In this study, the effect of alkanolamine additives, 2-amino-2-methyl-1-propanol (AMP) and 2-amino-2-methyl-1,3-propanediol (AMPD) on $CO_2$ absorption rate of $K_2CO_3$ solution and the formation of $KHCO_3$ crystals was investigated. The normalized $CO_2$ flux and the equilibrium $CO_2$ partial pressure were measured for 5 wt% additives and 30 wt% $K_2CO_3$ mixtures using a wetted-wall column unit at $40^{\circ}C$ and $60^{\circ}C$. Both additives showed the increased $CO_2$ absorption rate and lowered the equilibrium $CO_2$ partial pressure acting as promoters. Besides, AMPD which has two hydroxyl groups enhanced the formation of $KHCO_3$ solid product separated from the $CO_2$-rich solution from the results of batch cooling crystallization experiments.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.31-33
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• 2008

The study related that Red Phosphorus is surface coated by Al(OH)$_3$ using the proportion 1:1, 1:3, 1:5 respectively, and then take the coated red phosphorus as the core material, at the same time, use Melamine-Formaldehyde resin as the capsule materials for microcapsule processing. According to the TG analysis, the coated red phosphorus with the proportion 1:3 has the tiptop temperature of thermal decomposition, it reaches 376.20^{\circ}C$$. The same to the ratio of burning incomplete carbon it reaches 26.5%. The lowest moisture absorption ratio of the red phosphorus that used coated red phosphorus for microcapsule processing can reach 0.5% with the condition that thermal decomposition temperature decline 3.6%.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.67-67
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• 2012

Graphene, two-dimensional one-atom-thick planar sheet of carbon atoms densely packed in a honeycomb crystal lattice, exhibits fascinating electrical properties, such as a linear energy dispersion relation and high mobility in addition to a wide-range optical absorption and high thermal conductivity. Graphene's outstanding tensile strength allows graphene-based electronic and photonic devices to be flexible, bendable, or even stretchable. Recently many groups have reported high performance electronic and optoelectronic devices based on graphene materials, i.e. field-effect transistors, gas sensors, nonvolatile memory devices, and plasmonic waveguides, in which versatile properties of graphene materials have been incorporated into a flexible electronic or optoelectronic platform. However, there are several fundamental or technological hurdles to be overcome in real applications of graphene in electronics and optoelectronics. In this tutorial we will present a short introduction to the basic material properties and recent progresses in applications of graphene to electronics and optoelectronics and discuss future outlook of graphene-based devices.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.41-42
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• 2015

The concrete aggregate generates carbon dioxide in production but its demanding is gradually increased in accordance with the depletion of natural resources. Therefore we evaluated compatibility and basic physical properties of Silicon manganese slag generated in iron production as an applicable concrete aggregate. In our test, the silicon maganese slag shows 2.8g/㎥ of density in 10mm of maximum particle size similar to a natural aggregate, and its absorption rate was 0.3% similar to the electric furnace slag. Unit volume weight and ratio of absolute volume was respectively 2,001㎏/㎥ and 51%. Strength properties of Silicon manganese slag will be evaluated with further studies and experiments.

• Advances in concrete construction
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• v.6 no.4
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• pp.407-422
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• 2018

The study evaluates properties of brick having coal ash and explores the possibility of utilization of coal bottom ash and coal fly ash as an alternative raw material in the production of coal ash bricks. Lower cement content was used in the investigations to attain appropriate strength and prohibit high carbon content that is cause of environmental pollution. The samples use up to 7% of cement whereas sand was replaced with bottom ash. Bricks were tested for compressive strength, modulus of rupture, ultrasonic pulse velocity (UPV), water absorption and durability. The results showed mix proportions of bottom ash, fly ash and cement as 1:1:0.15 i.e., M-15 achieved optimum values. The coal ash bricks were well bonded with mortar and could be feasible alternative to conventional bricks thus can contribute towards sustainable development.