• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.478-485
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• 2022

The certification performance issued through an external business is sold to companies subject to the emission trading system allocation, and the company subject to the allocation can secure the quota by converting the purchased external business certification performance into offset credits. In this methodology, when fossil fuels that used existing oil boilers (by oil type) were replaced with boilers using propane gas with a relatively low carbon content, the amount of carbon dioxide emission reduction by oil type was recognized. As an initial analysis to make up for the insufficient quota of large corporations, the amount of carbon reduction emissions and emission rights trading was calculated.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.4
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• pp.1-7
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• 2020

This study quantified annual uptake and storage of carbon by urban greenspace in institutional lands and suggested improvement of greenspace structures to enhance carbon reduction effects. The study selected a total of five study cities including Seoul, Daejeon, Daegu, Chuncheon, and Suncheon, based on areal size and nationwide distribution. Horizontal and vertical greenspace structures were field-surveyed, after institutional greenspace lots were selected using a systematic random sampling method on aerial photographs of the study cities. Annual uptake and storage of carbon by woody plants were computed applying quantitative models of each species developed for urban landscape trees and shrubs. Tree density and stem diameter (at breast height) in institutional lands averaged 1.4±0.1 trees/100 ㎡ and 14.9±0.2 cm across the study cities, respectively. Of the total planted area, the ratio of single-layered planting only with trees, shrubs, or grass was higher than that of multi-layered structures. Annual uptake and storage of carbon per unit area by woody plants averaged 0.65±0.04 t/ha/yr and 7.37±0.47 t/ha, which were lower than those for other greenspace types at home and abroad. This lower carbon reduction was attributed to lower density and smaller size of trees planted in institutional lands studied. Nevertheless, the greenspace in institutional lands annually offset carbon emissions from institutional electricity use by 0.6 (Seoul)~1.9% (Chuncheon). Tree planting in potential planting spaces was estimated to sequester additionally about 18% of the existing annual carbon uptake. Enhancing carbon reduction effects requires active tree planting in the potential spaces, multi-layered/clustered planting composed of the upper trees, middle trees and lower shrubs, planting of tree species with greater carbon uptake capacity, and avoidance of the topiary tree maintenance. This study was focused on finding out greenspace structures and carbon offset levels in institutional lands on which little had been known.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.265-265
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• 2010

고분자 소재(polycarbonate; PC)의 표면을 보호하고 광학적 특성을 유지하기 위해 산화물 다층 박막과 비정질 탄소 박막(diamond-like carbon; DLC)을 전자빔 증착(e-beam evaporation)과 이온빔 증착(ion-beam deposition)을 이용하여 고분자 소재에 코팅하였다. 전자빔 증착으로 코팅된 실리콘과 티타늄 산화물 다층 박막은 소재 표면에서 가시광선의 반사율을 낮추는 효과를 가지고 있어 다양한 광학 코팅분야에서 이용되고 있다. 비정질 탄소 박막은 경도가 높고 마찰계수가 낮기 때문에 기계부품의 수명향상을 향상하기 위해 주로 사용되며, 본 연구에서는 고분자 소재의 최상층에 코팅하여 보호막으로 이용하였다. 고분자 윈도우에 산화물 다층 박막을 코팅하면 코팅되지 않은 기판과 비교하여 투과율이 향상되었으며 보호막으로 코팅된 비정질 탄소 박막에 의해서 일어나는 투과율 저하를 부분적으로 상쇄하는 효과를 보였다. 산화물 다층 박막의 수는 광학 분야에서는 주로 5-7층을 이용하지만 고분자 소재는 코팅 공정이 길어지면 열 변형이 일어날 수 있기 때문에 산화막의 층수를 낮추는데 초점이 맞춰졌다. 5층과 3층으로 코팅된 산화물 박막 모두 투과율이 향상되었으며 3층에 비해서 5층의 투과율 향상효과가 큰 것으로 나타났다. 고분자 소재의 투과율은 평균 약 90%이었으며 산화물 다층 박막과 비정질 탄소 박막을 코팅한 후 투과율이 약 81%로 측정되었다. 비정질 탄소 박막과 산화물 다층 박막을 적절하게 설계하고 코팅한다면 고분자 소재의 보호막으로 이용될 수 있을 것으로 판단된다.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.1
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• pp.1-13
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• 2024

Hydrogen is emerging as an essential material for carbon neutrality. In particular, Korea needs 22.9 million tons of imported clean hydrogen by 2050 to achieve carbon neutrality. However, a large amount of carbon is emitted during the import process, and market regulations are being discussed. This research estimates the carbon emissions of importing green hydrogen from Vietnam, Australia, and the United Arab Emirates to Korea, and calculates imported green hydrogen prices under carbon emission market regulations.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.665-677
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• 2021

This study analyzed the optimization method of forest management to enhance economic and public functions, as well as the interrelationship among timber production, carbon storage, and water conservation functions in Mt.Gari leading forest management zone. For these purposes, a forest management planning model was developed using Multi-Objective Linear Programming. The model had an objective function to maximize the total NPV (Net Present Value) of weighted timber production, carbon storage, water conservation, and constraints to limit the rate of change in timber production, percentage of each age-class and tree species area, percentage of conifers and broad-leaved trees area in each management zone, minimum timber production and timber sales amount. Based on the description of forest inventory and the comprehensive plan of Mt.Gari, we analyzed stand information and management constraints of the study area. We compared management alternatives using different weights in the objective function. Therefore, the total NPV was maximized in the alternative considering the three functions in equal proportion, rather than the alternatives of maximizing only one function. When all three functions were considered simultaneously, timber production offset the carbon storage and water conservation, and carbon storage and water conservation interacted synergistically. However, when considering only two of the three functions, all combinations of functions demonstrated tradeoffs with one other. Therefore, we discovered that by considering all three functions equally, rather than only one or two functions, the economic and public values of the study area can be maximized.

• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.117-127
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• 1982

In order to analyze the role of axial carbon atoms in rotational barrier of ethane, we take the carbonless ethane, as a model, which is made of six hydrogens in coordinates of ethane. The energy of the system is calculated by McWeeny's open-shell restricted Hartree-Foch selfconsistent-field (RHF-SCF) method, and the transition density on the staggered-to-eclipsed rotation is examined. As being expected, the eclipsed form of the model is more stable than the staggered one. Through the transition density comparison of this model and real ethane, it is found that the existence of the axial carbon atoms induces the electronic density to be diluted in the vicinity of protonic sites and to be attracted to the region of carbon atoms or further to C-C bond region as the barrier is traversed. This migration of electronic charge tell us that the barrier to the internal rotation of ethane originates from the fact that the magnitude of electronic energy depression is not large enough to offset the increased nuclear-nuclear repulsion on the staggered-to-eclipsed rotation.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.374-375
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• 2003

산업화에 따른 화석 연료의 연소, 기타 오염원에 의하여 생성되는 대류권의 에어로졸은 전 지구적인 평균값으로 볼 때, 약 -0.5 W/$m^2$의 복사강제력(radiative forcing)을 갖는 것으로 보고되고 있다. 이러한 음의 복사강제력은 일산화탄소, 염화불화탄소, 메탄 등과 같은 온실기체에 의한 양의 복사강제력을 상쇄시키는 정도보다 더 클 수 있다고 추측되고 있어 지속적으로 관리가 필요한 것으로 보인다. 본 연구는 국내에서 청정지역으로 꼽히고 있는 제주도 고산 측정소와 한라산 1100 고지 지역에서 에어로졸 시료를 채취하고, 고도에 따라 에어로졸 조성이 어느 정도 차이를 보이는지, 그리고 고도에 따라 에어로졸 성분의 특성이 어떻게 다른지를 비교하기 위한 목적으로 수행되었다. (중략)

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.31-38
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• 2019

This study quantified, through a direct harvesting method, storage and annual uptake of carbon from open-grown trees for three landscape tree species frequently planted in the southern region of Korea, and developed quantitative models to easily estimate the carbon reduction by tree growth for each species. The tree species for the study included Camellia japonica, Lagerstroemia indica, and Quercus myrsinaefolia, for which no information on carbon storage and uptake was available. Ten tree individuals for each species (a total of 30 individuals) were sampled considering various stem diameter sizes at given intervals. The study measured biomass for each part of the sample trees to quantify the total carbon storage per tree. Annual carbon uptake per tree was computed by analyzing the radial growth rates of the stem samples at breast height or ground level. Quantitative models were developed using stem diameter as an independent variable to easily calculate storage and annual uptake of carbon per tree for study species. All the quantitative models showed high fitness with $r^2$ values of 0.94-0.98. The storage and annual uptake of carbon from a Q. myrsinaefolia tree with dbh of 10 cm were 24.0 kg and 4.5 kg/yr, respectively. A C. japonica tree and L. indica tree with dg of 10 cm stored 11.2 kg and 8.1 kg of carbon and annually sequestered 2.6 kg and 1.2 kg, respectively. The above-mentioned carbon storage equaled the amount of carbon emitted from the gasoline consumption of about 42 L for Q. myrsinaefolia, 20 L for C. japonica, and 14 L for L. indica. A tree with the diameter size of 10 cm annually offset carbon emissions from gasoline use of approximately 8 L for Q. myrsinaefolia, 5 L for C. japonica, and 2 L for L. indica. The study pioneers in quantifying biomass and carbon reduction for the landscape tree species in the southern region despite difficulties in direct cutting and root digging of the planted trees.

• Journal of Environmental Policy
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• v.12 no.3
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• pp.123-159
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• 2013

We use a multi-regional dynamic computable general equilibrium model to explain an economic effect of $CO_2$ tax on the national and regional economy of Korea. First, we compare two $CO_2$ taxes: a region-specific $CO_2$ tax and a uniform $CO_2$ tax. In the region-specific tax, the $CO_2$ tax rate in the capital area and the south-eastern region is much greater than those in other regions. GDP loss resulting from the region-specific tax is bigger than that in the uniform tax. Second, we consider three options for tax recycling: consumption tax recycling, labor-income tax recycling, and corporate-income tax recycling. The corporate-income tax recycling has the least GDP-loss effect over the three options. These results support that it is more efficient to use a uniform $CO_2$ tax rate than a region-specific $CO_2$ tax rate and that the corporate-income tax recycling is more desirable in a sense of efficiency than the consumption and labor-income tax recycling options.

• Composites Research
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• v.34 no.6
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• pp.412-420
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• 2021

In this study, we measure the initial electrical conductivity of SCF/rubber specimens and SCF/rubber specimens with nickel particles respectively. The corresponding electrical conductivity with compressive strain on the specimens is also measured. Through this experiment, we observed the effects of the volume fraction of carbon fiber, nickel particles and external strain on the electrical conductivity. Experiments show that even a small difference in the volume fraction of SCF plays a major role in the change of the electrical conductivity and that the piezoresistivity increases due to fiber reorientation respond to external strain. In addition, the nickel particles contribute to improving the electrical conductivity in specimens with carbon fibers above the threshold volume fraction. It was confirmed that there is an effect of offsetting the increment in the piezoresistivity caused by the reorientation of carbon fibers according to external strain.