• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.125-126
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• 2022

As environmental problems around the world become serious, Korea has also raised the greenhouse gas reduction in the building sector to 32.8% compared to 2018, and efforts to reduce carbon in buildings are expanding. Recently, research is being actively conducted to reduce carbon in the long term by expanding the scope of greenhouse gas indirect emissions (Scope3), and even within the domestic Green Standard for Energy and Environmental Design(G-SEED) by quantitatively evaluating the environmental impact of buildings during the entire life cycle. However, it is difficult to accurately evaluate the carbon emission of the transportation process by assuming the material transport distance in the evaluation of the Life Cycle Assessment(LCA). Therefore, in this study, the main building materials of the building were selected through case evaluation and the carbon emission of the material transport process was derived based on the actual transport distance, and this was compared and analyzed with the theoretical LCA results.

• Journal of the Korean institute of surface engineering
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• v.56 no.5
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• pp.328-334
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• 2023

The carbon-based films have various properties, which have been widely applied in industrial application. However, it has critical drawback for poor adhesion between films and metal substrate. In the present work, we have deposited carbon-based films on injection mold steel by plasma assisted chemical vapor deposition (PACVD). In order to improve adhesion, prior to film deposition, the substrate was nitriding-treated using PACVD. And its effect on the adhesion was investigated. Due to the pre-nitriding, the amorphous carbon nitride (a-CN:H) films presented 10 times higher adhesion (34.9 N) than that of un-nitirided. In addition, a friction coefficient was decreased from 0.29 to 0.15 for the amorphous carbon (a-C:H) due to improved adhesion. The obtained results demonstrated that pre-nitriding considerably improved the adhesion, and the relationship among adhesion, hardness, and surface roughness was discussed in detail.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.569-577
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• 2023

This study selected seven carbon-neutral villages, considering the characteristics of each region, including all five administrative districts of Changwon City, and proposed activation plans based on business evaluations through surveys of local residents and FGIs with leaders. The analysis showed that carbon-neutral education was the most important factor for activating carbon-neutral villages, with a response rate of 91.9% for 17 multiple-choice questions, followed by legal (ordinance) arrangements at 79.3% and village organization building at 74.1%. Based on this, the following activation plans through the participation of residents who are involved in the project of creating a carbon-neutral village in Changwon City were proposed. First, the characteristics of each carbon-neutral village model were classified into a resource circulation-based model, an environmental creation-based model, an environmental education and experience event-based model, and an energy efficiency-based model. Second, it is necessary to create and present carbon-neutral village growth stage guidelines for the growth of carbon-neutral villages. Third, manuals and teaching materials related to carbon neutrality, such as theories, issues, and practices, need to be produced and distributed for leaders and activists to easily apply and access for self-government operation of the village. Finally, if a carbon-neutral support center that is legally installable in Changwon City is established, it is expected that the lives of local residents will become more sustainable for carbon-neutral living in preparation for climate crises.

• International Journal of Concrete Structures and Materials
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• v.8 no.1
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• pp.27-41
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• 2014

The use of carbon fibers (CF) and glass fibers (GF) were combined to strengthen concrete flexural members. In this study, data of tensile tests of 94 hybrid carbon-glass FRP sheets and 47 carbon and GF rovings or sheets were thoroughly investigated in terms of tensile behavior. Based on comparisons between the rule of mixtures and test data, positive hybrid effects were identified for various (GF/CF) ratios. Unlike the rule of mixtures, the hybrid sheets with relatively low (GF/CF) ratios also produced pseudo-ductility. From the calibrated results obtained from experiments, a new analytical model for the stress-strain relationship of hybrid FRP sheets was proposed. Finally, the hybrid effects were verified by structural tests of concrete members strengthened with hybrid FRP sheets and either carbon or glass FRP sheets.

• Transactions on Electrical and Electronic Materials
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• v.16 no.4
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• pp.198-200
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• 2015

The microwave plasma enhanced chemical vapor deposition (PECVD) system was used to grow a carbon nanowall (CNW) on a silicon (Si) substrate with hydrogen (H₂) and methane (CH₄) gases. To find the growth mechanism of CNW, we increased the growth time of CNW from 5 to 30 min. The vertical and surficial conditions of the grown CNWs according to growth time were characterized by field emission scanning electron microscopy (FE-SEM). Energy dispersive spectroscopy (EDS) measurements showed that the CNWs consisted solely of carbon.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1311-1320
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• 2005

The purpose of this research is to survey characteristics of microbial community and the removal efficiency of organic materials for biological activated carbon in water treatment plant. Coal based activated carbon retained more attached bacterial biomass on the surface of the activated carbon than the other activated carbon with operating time and materials. The heterotrophic plate count(HPC), eubacteria(EUB) and 4,6-diamidino-2-phenylindole(DAPI) counts were ranged from $0.95{\times}10^7$ to $52.4{\times}10^7$ CFU/g, from $3.8{\times}10^8$ to $134.2{\times}10^8$ cells/g and from $7.0{\times}10^8$ to $250.2{\times}10^8$ cells/g, respectively. The biomass of EUB and DAPI appeared to be much more $10^2$ than HPC, which were increasing in bed volume of 20,000 at the stage of steady-state. The change of microbial community by analyzing fluorescent in situ hybridization(FISH) method with rRNA-targeted oligonucleotide probes, the dominant group was $\alpha$-proteobacteria($\alpha$ group) and high G+C content bacteria(HGC) the lowest distributing rate before reaching the bed volume of 20,000. After reaching the bed volume of 20,000, $\alpha$ group and other groups of bacteria became decreased, on the other hand, the proportion of both $\beta$-proteobacteria($\beta$ group) and $\gamma$-proteobacteri($\gamma$ group) were increasing. Coconut and wood based activated carbons had similar trend with coal based activated carbon, but the rate of $\alpha$ group on coal based activated carbon had gradually increased. Bacterial production with the operating period appeared highest in coal based activated carbon at the range of $1.2{\sim}3.4\;mg-C/m^3{\cdot}h$ while the coconut and wood based activated carbon were ranged from 1.1 to 2.6 $mg-C/m^3{\cdot}h$ and from 0.7 to 3.5 $mg-C/m^3{\cdot}h$ respectively. The removal efficiency of assimilable organic carbon(AOC) showed to be highly correlated with bacterial production. The correlation coefficient between removal efficiency of AOC and bacterial production were 0.679 at wood based activated carbon, 0.291 at coconut based activated carbon and 0.762 at coal based activated carbon, respectively.

• Carbon letters
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• v.19
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• pp.23-31
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• 2016

Carbon rich fly ash was recently reported to have compositions that are ideal for use as a precursor and catalyst for carbon nanotube growth. This fly ash powder is mostly composed of pure carbon, predominantly present as sp². In this work, the effect of sonication time on the morphology and structural properties of carbon rich fly ash particles is reported. The obtained results show that ultrasound treatment is an effective tool for producing ultrafine particles/fragments with higher porosity, which might be suitable for the adsorption of gasses. Moreover, carbon nanoparticles (CNPs) of this fly ash were produced in parallel using the ball milling technique, and were evaluated as reinforcements for epoxy based composites. These CNPs have almost spherical shapes with particle sizes of around 30 nm. They were found to have strong C=O carbonyl group bonds, which might be generated during the ball milling process. The tensile testing results of a fly ash CNP reinforced epoxy composite showed significant improvements in the mechanical properties, mainly in the stiffness of the polymer. The stiffness value was increased by around 23% of that of neat epoxy. These CNPs with chemically active groups might also be useful for other applications.

• Journal of the Korean Institute of Rural Architecture
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• v.26 no.2
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• pp.9-16
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• 2024

In order to achieve carbon neutrality in the architectural field by 2050, this study analyzed the energy impact proportional to CO2 emissions of each technique, such as design methods, the properties of building structures, prefabrication methods, passive houses, and active facilities. In addition, the results were presented quantitatively in terms of carbon reduction, and corresponding housing cases were analyzed. The research method is limited to residential buildings at the Passive House energy level, and carbon reduction techniques and elements in architecture are examined through various literature and materials, and empirical cases are analyzed to determine the specific possibility of realizing carbon reduction in architecture. We want to secure it. Based on these analysis results, it was possible to suggest that it is possible to explore various approaches to carbon reduction in future residential construction. By combining the most efficient techniques according to the energy reduction level or goal setting of the building in question, we expect the possibility of achieving the goal of carbon reduction in the residential sector more realistically.

• Journal of the Korean institute of surface engineering
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• v.51 no.5
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• pp.332-336
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• 2018

Alkaline oxygen electrocatalysis, targeting anion exchange membrane alkaline-based metal-air batteries has become a subject of intensive investigation because of its advantages compared to its acidic counterparts in reaction kinetics and materials stability. However, significant breakthroughs in the design and synthesis of efficient oxygen reduction catalysts from earth-abundant elements instead of precious metals in alkaline media still remain in high demand. One of the most inexpensive alternatives is carbonaceous materials, which have attracted extensive attention either as catalyst supports or as metal-free cathode catalysts for oxygen reduction. Also, carbon composite materials have been recognized as the most promising because of their reasonable balance between catalytic activity, durability, and cost. In particular, heteroatom (e.g., N, B, S or P) doping on carbon materials can tune the electronic and geometric properties of carbon, providing more active sites and enhancing the interaction between carbon structure and active sites. Here, we focused on boron and nitrogen doped nanocarbon composit (BNC nanocarbon) catalysts synthesized by a solution plasma process using the simple precursor of pyridine and boric acid without further annealing process. Additionally, guidance for rational design and synthesis of alkaline ORR catalysts with improved activity is also presented.

• Advances in materials Research
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• v.13 no.3
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• pp.173-181
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• 2024

Fly ash, plastic waste, and clay are mineral materials and residues commonly found in Malaysia. In this study, these materials were fully utilized as raw materials for synthesizing carbon nanotubes (CNTs). Recycled polypropylene, previously used as a food container, served as a carbon source. Fly ash and clay were explored as potential substrates for CNTs growth. The recycled polypropylene was thermally decomposed at 900 ℃ in an inert environment for 90 minutes. Carbon atoms released during this process were deposited on fly ash and clay substrates, which had been immersed in a ferrocene solution to provide a metal catalyst for CNTs growth. The deposited products were characterized using a Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). Morphological analysis revealed that both fly ash and clay were coated with fiber-like structures, confirmed to be CNTs based on a diffraction peak around 26° from the XRD pattern. In conclusion, clay and fly ash demonstrate the potential to be utilized as substrates for CNTs formation.