• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.18-25
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• 2020

The purpose of this study is to investigate the mechanical and carbon-capture properties of foam concrete containing stainless steel argon oxygen decarbonization(AOD) slag. AOD slag was used as a binder, and foam concrete having a foaming ratio of 69 ± 0.5 % and a slurry density of 573.2 to 578.6 kg / ㎥ was produced. In order to examine the effect of carbonation, blended specimen was cured by two types : normal curing and CO₂ curing. As a result of the experiment, the specimens incorporating AOD slag showed higher compressive strength than Plain after CO₂ curing. According to the analysis of the image of foam concrete, it was confirmed that the ST30 has a lower total pore volume and average pore size than plain, resulting in high compressive strength. The SEM analysis confirmed the formation of calcite by carbonation of AOD slag. Through the thermogravimetric analysis, the increase of CO₂ uptake was confirmed by the incorporation of AOD slag. Foam concrete has a higher porosity than normal concrete, so it is expected that carbon-capture performance can be improved by using a AOD slag.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.253-260
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• 2015

Enlargement of street tree planting area is the proper and effective solution to reduce carbon dioxide. This solution bases on the ability of carbon storage and uptake by tree metabolism. However, the circumstance of road side has fatal disadvantages in tree metabolism such as growth and maturity because cutting and filling of roadsides cause unnatural soil composition. In this point, early rootage of street tree is the main factor of reducing carbon dioxide. This study aimed to find a appropriate transplantation planting method for sound and rapid rootage of street tree. For the study, Korean Mountain Ash(Sorbus alnifolia) were used for experimental groups. The groups were categorized by three groups such as trees produced on container with mulching treatment, trees produced in outdoor with mulching treatment, trees produced on container with weeding treatment. Each group consisted 10 trees with same size and transplanted in experimental site. Five months after transplanting, each group was estimated the biomass and carbon storage through a direct harvesting method. According to results of the study, the carbon storage of trees produced on container with mulching treatment is 42% more than trees produced in outdoor with mulching treatment. And the carbon storage of trees produced on container with mulching treatment is 19.5% more than trees produced on container with weeding treatment. These results may imply that transplantation of container produced tree with mulching treatment is the most rapid rootage among other groups. The weeding treatment is more effective than mulching treatment for rapid rootage of street trees.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.73-76
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• 1967

A nomogram of gas exchange ratio (R) in air breathing subjects ,was porposed which enables a simple and rapid determination of R value using the fractional concentrations of nitrogen and carbon dioxide in the expired or alveolar gas. The readable limit of R value seems less than 1/100 of R unit and the average difference between the values from the nomogram and the actually calculated values is less than 0.005 of R unit. The usefulness of this nomogram for rapid and frequent determinations of the oxygen uptake is also suggested.

• Journal of Haehwa Medicine
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• v.10 no.1
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• pp.55-65
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• 2001

This study was done to evaluate the immunomodulatory effects of KSDBT. KSDBT significantly enhanced the lymphocyte proliferation through 3H thymidine uptake and also increased T and T helper cell. It upregulated IL-2, IL-12(p35, p40) and INF-${\gamma}$. NO and carbon clearance were significantly increased by KSDBT. These results indicate KSDBT exert antitumor activity by immunomodulation of cytokines.

• Environmental Engineering Research
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• v.10 no.1
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• pp.22-30
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• 2005

Nitrite accumulation is not unusual in batch processes such as sequencing batch reactor (SBR) with high-strength of ammonium or nitrate wastewaters. A possible mechanism of nitrite inhibition on Acinetobacter was depicted in a biochemical model, which the protonated species, nitrous acid form of nitrite, affects proton relating transport at the proton-pumping site crossing the cell membrane under unlimited carbon and phosphorus conditions. This effect exerts inhibition of phosphorylation under aerobic condition and yields low APT/ADP ratio, consequently decrease poly-P synthesis and phosphorus uptake from outside the cell in the model.

• Asian Journal of Atmospheric Environment
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• v.6 no.3
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• pp.137-146
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• 2012

Poor indoor air quality is now worldwide concern due to its adverse impacts on our health and environment. Moreover, these impacts carry a significant burden to the economy. Various technical approaches (e.g., biological, activated carbon fiber (ACF), photocatlytic oxidation (PCO), etc.) have gained popularity in controlling indoor volatile organic compounds (VOCs). This is because removing indoor VOC sources or increasing ventilation rates is often not feasible or economical. This review provides an overview of the various air purification technologies used widely to improve indoor air quality. Although most of these technologies are very useful to remove indoor VOCs, there is no single fully satisfactory method due to their diversity and presence at the low concentration. To achieve technical innovations and the development of specific testing protocols, one should possess a better knowledge on the mechanisms of substrate uptake at VOC concentrations.

• Korean Journal of Environment and Ecology
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• v.14 no.3
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• pp.175-182
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• 2000

본 연구는 자연생태계 소목의 생장에 따른 탄소저장 및 흡수량 지표를 도출하고 용인시를 대상으로 임상유형의 영급별 탄소저장 및 흡수를 계량하였다. 침엽수 1주당 탄소저장 및 흡수량은 중부와 남부의 생장지역간 유의한 차이가 없었으나(p>0.05). 활엽수의경우는 남부지역에서 중부지역보다 더욱 많았다. 수목 1주당 탄소저장 및 흡수량은 활엽수가 동일 직경의 침엽수보다 더욱 많았으며, 그 차이는 직경생장과 더불어 증가하는 경향을 보였다. 용인시 자연생태계의 단위면적당 평균 탄소저장 및 흡수량은 역시 영급이 높을수록 많았으며, II 영급을 제외한 동일 영급내에서는 침엽수림보다는 혼효림이, 혼효림보다는 활엽수림이 더욱 많았다. 중부지역에서 생장하는 흉고직경 20cm 의 활엽수 1주는 약 175리터의 휘발유 소비로 인하여 배출되는 탄소량을 저장하고, 1ha의 IV 영급 활엽수림은 시민 57명이 화석연료 소비로 연간 배출하는 탄소량을 저장하였다. 본 연구의 탄소저장 및 흡수 지표는 직경 생장에 따른 삼림수목의 대기탄소농도 저감 가치를 용이하게 추정하는데 활용될 수 있다.

• Korean Journal of Environment and Ecology
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• v.24 no.5
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• pp.591-600
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• 2010

We estimated and compared C storages and annual $CO_2$ uptakes by 9 dominant tree species planted along the streets. DBH and age by tree species were measured in the sites selected considering the planting status and distributions of tree species, and biomass, C storage, growth rate, and annual $CO_2$ uptake were estimated for each species. As a result, L. tulipifera, M. glyptostroboides, P. occidentalis were classified into fast-growing group, P. serrulata, G. biloba, Z. serrata, S. japonica, A. palmatum showed intermediate growth rates, and P. densiflora was slow-growing. Average C storage per tree was 205kgC/tree and ranged from 518kgC/tree(L. tulipifera) to 41kgC/tree(P. densiflora). Average annual $CO_2$ uptake by urban street trees over their lifespan ranged from $7.6kgCO_2$/tree/y to $99.1kgCO_2$/tree/y and L. tulipifera was the greatest, followed by glyptostroboides and P. occidentalis, and P. densiflora was the lowest. Total annual $CO_2$ uptake by all street trees in Gyeonggi-do, estimated based on the annual $CO_2$ uptake by each species, was as small as approximately 0.67% of that by forest in Gyeonggi-do. However, urban trees are still important because forest area continues to decrease and urbanization occurs annually in Gyeonggi-do, and should be managed considering their multi-functional aspects, including mitigation of heat island effect and building energy saving(indirect $CO_2$ uptake).

• Carbon letters
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• v.10 no.2
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• pp.114-122
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• 2009

Crushed, depitted peach stones were impregnated activated with 50% $H_3PO_4$ followed by pyrolysis at $500^{\circ}C$. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional $N_2$ adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.

• Carbon letters
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• v.8 no.2
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• pp.108-114
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• 2007

In this work, activated carbon (AC) after $HNO_3$ modification was used as the support during the production of supported $TiO_2$ to increase the high deposition efficiency and the photocatalytic activity. The results of $N_2$ adsorption showed that the BET surface area of samples decreased with an increasing of the concentration of $HNO_3$ due to the penetration of $TiO_2$. From XRD data, a single crystal structure of anatase peak was observed in diffraction patterns for the AC coated with titanium complexes. From the SEM results, almost all particles were aggregated with each other at the carbon surface and AC was covered with $TiO_2$ particles in all of the samples. The EDX spectra show the presence of C, O, Ti and other elements. It was also observed a decreasing of amount of C content with increasing Ti and O content from the EDX. The results of FT-IR revealed that the modified AC contained more surface oxygen bearing groups than that of the original AC. The effect of surface acidity and basity calculated from Boehm titration method was also evaluated from correlations as a function of NaOH, $NaHCO_3$, and $Na_2CO_3$ uptake. The surface modification of AC by $HNO_3$ leads to an increase in the catalytic efficiency of AC/$TiO_2$ catalysts, and the catalytic efficiency increases with increasing of $HNO_3$ concentration.