• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.317-320
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• 2000

The optimal temperature and pH for both mycelial growth and exe-biopolymer production by Cordyceps millitaris in shake flask culture were found to be $20^{\circ}C$ and 6.0, respectively. Sucrose (4%) and corn steep powder (1%) were the most suitable carbon and nitrogen source for mycelial growth and exo-biopolymer production. The maximum specific growth rate $(0.142h^{-1})$ was achieved when sucrose was used as the sole carbon source. Exo-biopolymer production was increased with the increase in C/N molar ratio concentration, probably due to the facilitated carbon uptake. Under the optimal culture conditions, the maximum mycelial growth exe-biopolymer concentration were reached to around 13.3 g dry cell weigh/l and 3.33 g/l, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.4
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• pp.217-223
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• 1994

Carbon dioxide emission has been increased by 7% in an annual average toward 212.5 million tons in 1990 from 108.7 million tons in 1980. Among emissions in 1990, industry, residential / commercial, transportation, other and non-energy have occupied 91.12, 68.04, 42.13, 7.13 and 4.09 million tons respectively. The Korea-scenarios corresponding to those of IPCC that is Intergovernmental Panel on Climate Change (A : modest control of $CO_2$; B : stringent control of $CO_2$, C: shifting fuel to renewable and nuclear energy in the second half of the next century ; and D: shifting fuel to renewable and nuclear energy in the first half of the next century show that the global-scale contributions of atmospheric $CO_2$ concentration are 0.77, 0.64 and 0.78% in 2050 for cases A,B, and C respectively. In all cases, the contributions were smaller than 0.09 % in 1985.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.10
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• pp.1037-1043
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• 1990

Diamond thin films were synthesized from the mixed gases of methane and hydrogen on silicon substrates by RF plasma chemical vapor deposition and deposited films were investigated by SEM, X-ray diffractometry and Raman spectroscopy. It is found that high quality diamond-like carbon films were successfully synthesized by PECVD under the deposition condition of 1-10 vol% of methane concentration, 0.15-0.4torr of reactor pressure, 500W of RF power, and 5-20hr of reaction time. Especially, cubo-octahedral diamond-like carbon particles were synthesized by employing 1.0 vol % of methane concentration and 0.4torr of the reactor pressure.

• Journal of the Korean Applied Science and Technology
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• v.20 no.4
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• pp.309-315
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• 2003

Extraction of Natural Artemisia by using super critical carbon dioxide is operated under $40-50^{\circ}C$ and 200-250 atm, thus, conversion rate is very low as 7wt% while high energy is being wasted. When Natural Artemisia Extract is applied in the control of microbe, concentration and reaction time greatly affected to the growth of microbe. Especially, when refined oil concentration from Natural Artemisia added more than 1,000ppm, staphylococcus aureus and fungi are terminated completely. Thus, it is proven that Natural Artemisia Extract has antimicrobial effect.

• Journal of the Korean Chemical Society
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• v.62 no.2
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• pp.79-86
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• 2018

This study reported the adsorption of Cu(II) ions onto activated carbon prepared from Myristica Fragrans shell (MFS AC) over independent variables of contact time, activating chemical (NaOH) concentration, initial adsorbate concentration, initial pH of adsorbate solution and adsorption temperature. The MFS AC structure, morphology and total surface area were characterized by FTIR, SEM and BET techniques, respectively. The Cu(II) ions adsorption on the MFS AC (activated using 0.5 M NaOH) fitted best to Freundlich adsorption isotherm (FAI), and the FAI constant obtained was 0.845 L/g at $30^{\circ}C$ and pH 4.5. It followed the pseudo first order of adsorption kinetic (PFOAK) model, and the PFOAK based adsorption capacity was 107.65 mg/g. Thermodynamic study confirmed the Cu(II) ions adsorption should be exothermic and non-spontaneous process, physical adsorption should be taken place. The total surface area and pore volume based on BET analysis was $99.85m^2/g$ and 0.086 cc/g, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.3
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• pp.325-331
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• 2003

A biofilter study was conducted by changing inlet concentration and residence time for the removal of gaseous benzene and ethylene. In addition, carbon dioxide produced from the biofilters was investigated. Over 96% of benzene was removed at the residence times of 2 and 4.3 min, and inlet benzene concentrations of 220∼300 ppm. The ethylene biofilter was capable of achieving ethylene removal efficiency as much as 100％ at a residence time of 14 min, and inlet concentrations of 99∼290 ppm. At a steady state, the carbon dioxide of 409∼611 ppm was produced with an ethylene inlet concentration of 290 ppm. Most of benzene and ethylene were degraded at lower part of the biofilters where more microbial activity occurred.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.1
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• pp.72-78
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• 2014

The study has been designed to develop water vapor supply for semiconductor industry, industrial gas manufacturing, impurities analysis, and fuel cell. Water concentration in air reached $1019{\mu}mol/mol$ at dew temp ($-20^{\circ}C$) and water concentration in CO2 reached $127{\mu}mol/mol$ at dew temp ($-40^{\circ}C$. Carbon dioxide needs more wet gas than air because interaction potential of carbon dioxide shows more strong attraction than air.

• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1560-1564
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• 2005

The influence of cetyltrimethylammonium bromide (CTAB) on the electrochemical behavior of bisphenol A at the carbon paste electrode (CPE) was investigated. CTAB, with a hydrophobic C-H chain, can adsorb at the CPE surface via hydrophobic interaction and then change the electrode/solution interface, and finally affects the electrochemical response of bisphenol A, confirming from the remarkable oxidation peak current enhancement. The electrode process of bisphenol A was examined, and then all the experimental parameters which affects the electrochemical response of bisphenol A, such as pH value of the supporting electrolyte, accumulation potential and time, potential scan rate and the concentration of CTAB, were examined. Finally, a sensitive and simple voltammetric method was developed for the determination of bisphenol A. Under the optimum conditions, the oxidation peak current of bisphenol A varied linearly with its concentration over the range from $2.5\;{\times}\;10^{-8}\;to\;1\;{\times}\;10^{-6}$ mol/L, and the detection limit was found to be $7.5\;{\times}\;10^{-9}$ mol/L. This method was successfully employed to determine bisphenol A in some waste plastic samples.

• Composites Research
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• v.21 no.2
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• pp.25-30
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• 2008

A hemispherical microbond specimen adhered onto single carbon fiber has been proposed for evaluating the interfacial shear strength between epoxy and carbon fiber. Hemispherical microbond specimens showed low interfacial shear strength data and its small standard deviation as compared with the droplet one, which seemed to be caused by the reduction of the meniscus effects and of the stress concentration in the region contacting with the tip of pin hole. In comparison with the droplet specimen the hemispherical specimen showed the shear stress distribution similar to the cylindrical one in that low stress concentration arose around the contacting region. Average interfacial shear strength obtained by the hemispherical ones represented a good correlation with the hardness of the epoxy matrix.

• Carbon letters
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• v.8 no.1
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• pp.6-11
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• 2007

Carbon/$TiO_2$ composites were prepared by $CCl_4$ solvent mixing method with different mixing ratios. Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the Carbon/$TiO_2$ composite series showed a good adsorptivity and photo decomposition activity. The BET surface area for the carbon layer in the sample increases to increasing with pitch contents. The SEM results present to the characterization of porous texture on the Carbon/$TiO_2$ composite and pitch distributions on the surfaces for all the materials used. From XRD data, a weak and broad carbon peak of graphene with pristine anatase peaks were observed in the X-ray diffraction patterns for the Carbon/$TiO_2$. The EDX spectra show the presence of C, O and S with strong Ti peaks. Most of these samples are richer in carbon and major Ti metal than any other elements. Finally, the excellent photocatalytic activity of Carbon/$TiO_2$ with slope relationship between relative concentration (C/$C_0$) of MB and t could be attributed to the homogeneous coated pitch on the external surface by $CCl_4$ solvent method.