• 펄프종이기술
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• 제31권4호
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• pp.58-68
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• 1999

This experiment was to investigate decoloization characteristics of E1 effluents from the bleaching plant of pulp mill with three white-rot fungi(Trametes versicolor, Ganoderma appanatum and Pleurotus ostreatus).In addition, the effect of carbon and nitrogen resources was discussed on its decolorization. The color removal of E1 effluent during shaking and stationary cultures were 72% and 80%, respectively. Stationary culture was more effective on decolorization of E1 effluent compared to the shaking culture. The optimum inoculum weight was 1.0g based on dry weight of mycelia . The decolorization medium I showed 88% of the color removal of E1 effluent with in one day cultivation of T.versicolor and P.ostreatus . Color removal was increased from 87% to 90%. T.versicolor and P.ostreatus by the addition of 0.5% glucose. By addition of nitorgen sources(ammonium sulfate and ammonium choride), medium was much higher than that of carbon source. With 0.1% ammoniumm sulfate, P.ostreatus and T.versicolor showed 94% and 92% of the color removal within one day of cultivation , respectively. On decolorization medium II, T.versicolor and P.ostretus were 94% of oclor removal with addition of carbon source. The addition of nitrogen source was much more efficient than that of carbon source. With 0.1% amminium chloride, T.versicolor and P.ostreatus showed 95% of its color removal . The decolorization medium II was higher color removal than medium I, and also MnP and laccase were produced. However, the decolorization medium I produced a little MnP and laccase activity. It could be suggested that MnP and laccase may play an important role in decolorization of E1 effluent.

• Journal of the Korean Wood Science and Technology
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• 제38권5호
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• pp.429-438
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• 2010

In this study, effect of carbon source on the hydrolytic ability of the enzyme from Fomitopsis pinicola, a brown rot fungi, for lignocellulosic biomass were examined on two lignocellulosic biomasses (rice straw and wood) without any pretreatment. Cellulase activities of crude enzyme from F. pinicola, which was cultured on softwood mixture as a carbon source, were 19.10 U/$m{\ell}$ for endo-${\beta}$-1,4-gulcanase (EG), 36.1 U/$m{\ell}$ for ${\beta}$-glucosidase (BGL), 7.27 U/$m{\ell}$ for cellobiohydrolase (CBH), and 7.12 U/$m{\ell}$ for ${\beta}$-1,4 xylosidase (BXL). Softwood mixture as a carbon source in F. pinicola comparatively enhanced cellulase activities than rice straw. The optimal pH and temperature of the cellulase was identified to pH 5 and $50^{\circ}C$for the hydrolysis of rice straw. Under these condition rice straw was hydrolyzed to glucose by the cellulase up to $32.0{\pm}3.1%$ based on the glucan amount of the rice straw for 72 h, while the hydrolytic capability of commercial enzyme (Celluclast 1.5${\ell}$) from rice straw to glucose was estimated to $53.7{\pm}4.7%$ at the same experimental condition. In case of addition of Tween 20 (0.1% w/w, substrate) to the cellulase the hydrolysis of rice straw to glucose was enhanced to $38.1{\pm}2.0%$.

• 한국약용작물학회지
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• 제2권1호
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• pp.44-50
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• 1994

1. 2.4-D 0.5mg/1에서 배발생캘러스 생장과 발생빈도가 가장 양호하였다. 2. 배지 중에서 MS배지가 체세포배 형성과 생육에 좋았으며, 1X MS배지 보다 1/2X MS배지가 배형성에 더 효과적이었다. 3. 탄소원으로는 sucrose가 효과적이었다. 농도는 1%처리가 가장 양호하였으며 농도가 높아짐에 따라 체세포배 형성이 억제되었다. 4. Sucrose 대신 sugar 처리에서도 체세포배 형성이 앙호하였다. 5. 질소원으로는 $KNO_3\;825mg\;/\;l$ 와 $NH_{4}NO_3$ 238mg /l 처리가 배발생에 가장 효과적이었다.

• 한국표면공학회지
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• 제42권4호
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• pp.179-185
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• 2009

Diamond-like carbon(DLC) films were deposited by linear ion source(LIS)-physical vapor deposition method changing the anode voltages from 800 V to 1800 V, and characteristics of the films were investigated using residual stress tester, nano-indentation, micro raman spectroscopy, scratch tester and Field Emission Scanning Electron Microscope(FE-SEM). The results showed that the residual stress and hardness increased with increasing the ion energy up to anode voltage of 1400 V. It was also found that the content of $SP^3$ carbon increased with increasing the anode voltage $SP^3/SP^2$ ratio through investigation of $SP^3/SP^2$ ratio by the micro-raman analysis. From these results, it can be concluded that the physical properties of DLC films such as residual stress and hardness are increased with increasing the anode voltage. These results can be explained that 3-dimensional cross-links between carbon atoms and Dangling bond are enhanced and the internal compressive stress also increased with increasing the anode voltage. The optimal anode voltage is considered to be around 1400 V in these experimental conditions.

• 한국물환경학회지
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• 제22권3호
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• pp.462-467
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• 2006

An improvement of nitrogen and phosphorus removal in SBR using the elutriated acids from the food waste as an external carbon source was investigated in this study. The food waste was elutriated at $35^{\circ}C$ and pH 9 to produce the external carbon source. The elutriate of food waste were continuously collected. The elutriated liquid contained VFAs of 39,180 mg/L representing soluble COD of 44,700 mg/L. The SBR showed poor denitrification and EBPR (enhanced biological phosphorus removal) without elutriated VFAs addition. An average denitrification rate was 0.4 mg NOx-N/g MLVSS/day. In turn, EBPR was also inhibited by this poor denitrification because the remaining nitrate in anaerobic phase resulting a poor denitrification. On the other hand, the denitrification in anoxic phase significantly improved with an elutriated VFAs addition. Nitrate removal was 82% while the denitrification rate was 2.9 mg NOx-N/g MLVSS/day with 18.4 mL/cycle of elutriated VFAs. With the enhanced denitrification, nitrate concentration in anaerobic phase could effectively be controlled to a very low level. The elimination of nitrate inhibition in anaerobic phase resulted enhancement of EBPR. The specific phosphate release rate was $1.9mg\;PO_4^{3-}-P/g\; MLVSS/day$ with less than 0.5 mg/L of $PO_4^{3-}-P$ concentration.

• Advances in nano research
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• 제15권3호
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• pp.263-275
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• 2023

The electron transport properties of Y-type zigzag branched carbon nanotubes (CNTs) are of great significance for micro and nano carbon-based electronic devices and their interconnection. Based on the semi-empirical method combining tight-binding density functional theory and non-equilibrium Green's function, the electron transport properties between the branches of Y-type zigzag branched CNT are studied. The results show that the drain-source current of semiconducting Y-type zigzag branched CNT (8, 0)-(4, 0)-(4, 0) is cut-off and not affected by the gate voltage in a bias voltage range [-0.5 V, 0.5 V]. The current presents a nonlinear change in a bias voltage range [-1.5 V, -0.5 V] and [0.5 V, 1.5 V]. The tangent slope of the current-voltage curve can be changed by the gate voltage to realize the regulation of the current. The regulation effect under negative bias voltage is more significant. For the larger diameter semiconducting Y-type zigzag branched CNT (10, 0)-(5, 0)-(5, 0), only the value of drain-source current increases due to the larger diameter. For metallic Y-type zigzag branched CNT (12, 0)-(6, 0)-(6, 0), the drain-source current presents a linear change in a bias voltage range [-1.5 V, 1.5 V] and is symmetrical about (0, 0). The slope of current-voltage line can be changed by the gate voltage to realize the regulation of the current. For three kinds of Y-type zigzag branched CNT with different diameters and different conductivity, the current-voltage curve trend changes from decline to rise when the branch of drain-source is exchanged. The current regulation effect of semiconducting Y-type zigzag branched CNT under negative bias voltage is also more significant.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1331-1337
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• 2006

A mathematical model has been proposed for the batch culture of Agaricus blazei with mixed carbon sources of glucose and dextrin. In the proposed model, the metabolism of A. blazei was divided into three parts: cell growth, exopolysaccharides (EPS) production, and another EPS production pathway activated by dextrin hydrolysis. Each pathway was described mathematically and incorporated into the mechanistic model structure. Batch cultures were carried out with six different carbon source compositions. Although parameters were estimated by using the experimental data from the two extreme cases such as glucose only and dextrin only, the model represented well the profiles of glucose, cell mass, and EPS concentrations for all the six different carbon source mixtures, showing a good interpolation capability. Of note, the lag in EPS production could be quite precisely predicted by assuming that the glucose-to-cell mass ratio was the governing factor for EPS production.

• Carbon letters
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• 제15권4호
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• pp.219-237
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• 2014

The element carbon has been used as a source of energy for the past few hundred years, and now in this era of technology, carbon has played a significant and very prominent role in almost all fields of science and technology. So as an honour to this marvellous element, we humans should know about its various forms of existence. In this review article, we shed light on all possible carbon-allotropes; similarities in their synthesis techniques and the starting materials; their wide range of possible availability; and finally, future perspectives and applications. A brief introduction is given on the types, structures, and shapes of the allotropes of carbon for a better understanding.

• 한국레이저가공학회지
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• 제5권2호
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• pp.17-22
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• 2002

Characteristics of micro carbon structures fabricated with laser-induced chemical vapor deposition (LCVD) are investigated. An argon ion laser (λ＝514.5nm) and ethylene gas were utilized as the energy source and precursor, respectively. The laser beam was focused onto a graphite substrate to produce carbon deposit through thermal decomposition of the precursor. Average growth rate of a carbon rod increased for increasing laser power and pressure. Micro carbon rods with good surface quality were obtained at near the threshold condition. Micro carbon rods with aspect ratio of about 100 and micro tubular structures were fabricated to demonstrate the possible application of this method to the fabrication of three-dimensional microstructures. Laser Raman spectroscopic analysis of the micro carbon structures revealed that the carbon rods are consisting of amorphous carbon.

• 한국대기환경학회지
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• 제25권1호
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• pp.75-89
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• 2009

The purpose of this study was to identify $PM_{2.5}$ sources and to estimate their contributions to the border of Yongin-Suwon area, based on the analysis of the $PM_{2.5}$ mass concentration and the associated inorganic elements, ions and carbon components. The contribution of $PM_{2.5}$ sources were estimated by using a positive matrix factorization (PMF) model to identify air emission sources. For this study, $PM_{2.5}$ samples were collected from May, 2007 to April, 2008. The inorganic elements were analyzed by an ICP-AES. The ionic components in $PM_{2.5}$ were analyzed by an Ie. The carbon components were also analyzed by DRI/OGC analyzer. After performing PMF modeling, a total of 12 sources were identified and their contributions were quantitatively estimated. The contributions from each emission source were as follows: 11.3% from oil combustion source, 3.4% from bus/highway source, 5.8% from diesel vehicle source, 4.7% from gasoline vehicle source, 8.8% from biomass burning source, 15.1 % from secondary sulfate, 5.2% from secondary nitrate source, 13.4% from industrial related source, 4.1% from Cl-rich source, 19.6% from soil related source, 1.0% from aged sea salt, and 7.4% from coal combustion source, respectively. This study provides basic information on the major sources affecting air quality, and then it will help to effectively control $PM_{2.5}$ in this study area.