• Carbon letters
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• v.10 no.1
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• pp.5-8
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• 2009

We measured the non-carbon content of single-walled carbon nanotubes (SWCNTs) in SWCNT soot using thermogravimetric analysis. The weight increased percentage by the oxidation of metal in the raw soot is well obtained by TGA graph which was confirmed with ICP-AES, XRD, and XPS. This work will be very useful for the purity precise evaluation of SWCNT with UN-vis-NIR spectroscopy.

• Journal of the Korean Ceramic Society
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• v.44 no.11
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• pp.607-612
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• 2007

Zn-AC and Zn-H-AC series prepared from non- and surface-modified activated carbon were investigated in terms of their hydrogen production capacity. An increase in the concentration of the zinc salts used with these series was shown to lead to a decrease in the values of the surface textural properties. The existence of zinc complexes on the surface was confirmed from an analysis of XRD data. The SEM micrographs of the two different sample types showed that the transformation of the carbon surface with an acid pre-treatment significantly change the metal contents on the surfaces of the carbon matrix. The EDX spectra indicated that all of the samples were richer in the amount of oxygen and zinc compared to any other elements. The results obtained using the Boehm's titration method showed that the positive introduction of the acidic groups on the carbon surfaces with the acid treatment is correlated with an increase in the amounts of zinc complexes with variation of the acidic groups. In terms of the hydrogen production performance, the volume fractions of the Zn-H-AC series were found to produce higher amounts than the Zn-AC series as a function of the metal contents considering the effects of the acid treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.181-193
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• 2016

This experiment was conducted to evaluate the effect of carbonized rice hull (CRH) application on soil carbon storage and $N_2O$ emissions from upland soil. It was used at different rates of 0, 5, 10 and $20Mg\;ha^{-1}$. During the Chinese cabbage cultivation, several soil chemical characteristics such as soil moisture, temperature and soil carbon were observed. Also, $CO_2$ and $N_2O$ emissions were monitored. Soil organic matter contents slightly increased with carbonized rice hull applied in all the treatments. The soil carbon contents with application rate of 0, 5, 10 and $20Mg\;ha^{-1}$ were 0, 1.3, 1.2 and $2.6g\;kg^{-1}$, respectively. It was observed that soil carbon content was higher with increasing CRH application rate. Total nitrogen contents of soil applied with CRH relatively decreased with the course of time. However, $NO_3$-N contents in the soil with CRH application rate of 5, 10 and $20Mg\;ha^{-1}$ were 28.6, 25.7 and $21.5mg\;kg^{-1}$ at the end of experiment, respectively. $CO_2$ emission at the $5Mg\;ha^{-1}$ application of CRH was higher about 18.9% than non-treatment, whereas those of $10Mg\;ha^{-1}$ and $20Mg\;ha^{-1}$ treatment were lower 14.4% and 11.8% compared to non-treatment, respectively. Also, it was shown that $N_2O$ emission reduced by 19.9, 28.3 and 54.0% when CRH was applied at 5, 10 and $5Mg\;ha^{-1}$, respectively.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.76-84
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• 1996

Flue-cured tobaccos(cv. NC82, grade AB3O-1) expanded by super steam, volatile organic solvents(tricuorofluoromethane, propane), carbon dioxide, nitrogen, and by freeze-drying were examined for their physico-chemical properties. The expanding rate by using the organic solvents or carbon dioxide at the impregnated pressure was 70% or more, whereas the rate by super steam and freeze-drying was 49.4 and 42.9%, respectively. The contents of total sugar, alkaloid and ether extracts of the expanded tobacco by organic solvents or carbondioxide were decreased to 27.6, 20% or more, and 13%, respectively, when compared to non-expanded one. The contents of citric acid of the tobacco expanded by using trichlorofluoromethane and carbon dioxide were increased to 19.1, 14.0%, respectively. Linoleic acid in the tobacco expanded by super steam or trichlorofluoromethane was also increased to 17.3%, but malonic acid in the tobacco expanded by super steam was 18.5% less than that in the non-expanded one. Nineteen essential oil among 22 assayed in this experiment were decreased in the expanded tobaccos. Key words : expanding method, tobacco, physico-chemical properties.

• Journal of Soil and Groundwater Environment
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• v.13 no.2
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• pp.21-29
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• 2008

Sorption and desorption processes play an important role in the transport and fate of organic contaminants in subsurface system. In this study, sorption and desorption characteristics of atrazine in 7 soils selected at the Gwangju area were investigated. Soil organic carbon contents ranged from 0.42 to 2.82%. Sorption and desorption experiments were performed in batch slurries. Sorption distribution coefficient ($K_d$) of atrazine were ranged from 0.48 to 3.26 l/kg and $K_d$ value increased with increasing organic carbon contents except of Kyongbang and Youngdong soils. Single desorption data were analyzed by the three-site desorption model including equilibrium, non-equilibrium and non-desorbable site. Non-desorbable site fractions of atrazine in all soils were enumerated and non-desorbable atrazine was observed in seriesdilution desorption experiment. Sorption/desorption hysteresis was also observed in the series-dilution desorption experiment.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.83-88
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• 2003

The woodceramics are porous amorphous carbon and glassy carbon composite materials. Woodceramics attracted a lot of attention in recent years because they are environmentally friendly and because of their unique functional characteristics such as catalysis, moisture absorption, deodorization, purification, carrier for microbial activity, specific stiffness, corrosion and friction resistance, and their electromagnetic shielding capacity. In this paper, we made new products of clay-woodceramics to investigate the industrial analysis and ethylene gas adsorption for basic data of building- and packging- materials keeping fruit fresh for a long time. Clay-woodceramics were carbonized for 3 h of heating in a special furnace under a gas flow of nitrogen(15 ml/min.) from 3 layers-clay-woodparticleboard made from pallet waste wood, phenol- formaldehyde resin(hereafter PF, Non volatile content:52%, resin content 30%), and clay(10%, 20% and 30%). Carbonization temperature was 400℃, 600℃ and 800℃. Experimental results shows that the higher the carbonization temperature, the higher the fixed carbon and the lower the volatile contents. The higher the clay content, the more the ash content. The higher the carbonization temperature, the more the ethylene gas adsorption. Carbonization temperature of 800℃ gave the best reslts as same as that of white charcoal and activated carbon.(800℃-clay-woodceramic: 5.36 ppm, white charcoal: 5.66 ppm, activated carbon: 5.79 ppm) The clay contents did not make difference of ethylene gas adsoption.

• Ecology and Resilient Infrastructure
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• v.2 no.2
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• pp.177-184
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• 2015

This study assessed the performance of activated carbon (AC) amendment to treat polycyclic aromatic hydrocarbons (PAHs) including both parent- and alkylated-moieties in sediment impacted by diesel. A field-collected, diesel-impacted sediment with a NAPL content of 1% was used for the study. No. 2 diesel fuel is weathered by heating at $70^{\circ}C$ for 4 days to obtain a weathered diesel sample having C3-naphthalenes to C2-phenanthrenes/anthracenes (N2/P3) ratio similar to the original sediment. The sediment samples spiked with the weathered diesel to obtain non-aqueous phase liquid (NAPL) contents of 1, 5 and 10% were contacted with AC with a dose of 5% as sediment dry weight for 1 month. By the AC-sediment contact, the freely-dissolved equilibrium concentrations were substantially reduced. Even for sediment with 10% NAPL content, the reductions in the freely-dissolved concentrations were 92% and 75% for total parent-and alkylated-PAHs, respectively. The effect of NAPL contents on the performance of AC was negligible for parent-PAHs, while for alkylated-PAHs, a slightly reduced AC performance was observed. The results suggest that the AC amendment can be an effective option for the treatment of petroleum-impacted sediment with relatively high NAPL contents.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.4
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• pp.256-262
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• 2021

A carbon felt electrode was prepared using ozone and ammonia sequential treatment and applied as an electrode for a vanadium redox flow battery (VRFB). The physical and electrochemical analyses demonstrate that the oxygen groups facilitate nitrogen doping in the carbon felt. Carbon felt (J5O3+NH3), which was subjected to ammonia heat treatment after ozone treatment, showed higher oxygen and nitrogen contents than carbon felt (J5NH3+O3), which was subjected to ammonia heat treatment first and then ozone treatment. From the charging/discharging of VRFB, the J5O3+NH3 carbon felt electrode showed 14.4 Ah/L discharge capacity at a current density of 150 mA /cm², which was 15% and 33% higher than that of J5NH3+O3 and non-activated carbon felt (J5), respectively. These results show that ozone and ammonia sequential treatment is an effective carbon felt activation method to increase the performance of the vanadium redox flow battery.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.676-685
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• 2018

This study is to compare carbon budget between serpentine sites and non-serpentine sites dominated by Pinus densiflora forest in the Andong serpentine area where has high values of magnesium and low values of calcium, and are usually deficient in nitrogen and phosphorus, but rich in heavy metals such as nickel, chrome, cobalt, etc. and to measure soil $CO_2$ efflux and environmental factors between January 2017 and December 2017. Soil $CO_2$ efflux was measured with LI-6400 once a month; the soil temperature at 10 cm depth, air temperature, soil moisture contents, and solar radiation were measured in continuum. Soil $CO_2$ efflux in the serpentine area and non-serpentine were $151.71{\pm}75.09g\;CO_2{\cdot}m^{-2}month^{-1}$(42.48 ~ 262.61 g $CO_2{\cdot}m^{-2}month^{-1}$) and $165.09{\pm}118.96g\;CO_2{\cdot}m^{-2}month^{-1}$(20.94 ~ 449.24 g $CO_2{\cdot}m^{-2}month^{-1}$), respectively. Carbon storage in the serpentine area and non-serpentine area were 91.90, $222.85ton{\cdot}ha^{-1}$, respectively. Carbon absorption in the serpentine area and non-serpentine area were 7.99, $17.41ton{\cdot}ha^{-1}yr^{-1}$, respectively. Carbon budget in the serpentine area and non-serpentine area were absorbs 5.3, $14.49ton{\cdot}Cha^{-1}yr^{-1}$, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.35-36
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• 2006

In Nd:YAG laser welding, evaluation methods of welding flaw are various. But, the method due to fume shape is difficult to classification of welding flaw. The Nd:YAG laser process is known to have high speed and deep penetration capability to become one of the most advanced welding technologies. At the present time, some methods are studied for measurement of fume shape by using high-speed camera and photo diode. This paper describes the machining characteristics of SM45C carbon steel welding by use of an Nd:YAG laser. In spite of its good mechanical characteristics, SM45C carbon steel has a high carbon contents and suffers a limitation in the industrial application due to the poor welding properties. In this study, fume shape was measured by infrared thermal camera that is non-contact/non-destructive thermal measurement equipment through change of laser generating power, speed, focus. Weld was performed on bead-on method. Measurement results are compared as two equipments. Here, two results are composed of measurement results of fume quantities due to fume shape by infrared thermal camera and inspection results of weld bead include weld flaws by ultrasonic inspector.