• Title/Summary/Keyword: Oxidation of carbon

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Removal of Phenol Loaded with Activated Carbon by Potentiostatic Method (정전위전해에 의한 활성탄에 함유된 페놀 제거)

  • 김성우;박승조
    • Resources Recycling
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    • v.10 no.4
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    • pp.18-23
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    • 2001
  • Air pollutants, phenol was generated in case of thermal regeneration of used activated carbon loaded with phenol and because of this problem, removal process of phenol were studied. Electrolytic oxidation of samples, used S.company granular activated carbon (WS-GAC), used C.company granular activated carbon (WC-GAC) and used L.company granular activated carbon (WL-GAC) loaded with phenol carried out by potentiostatic method in this study. In case of experiment was to come into operation in condition of samples containing 100 mg/g phenol, supporting electrolyte was 1.0% sodium chloride solution, Ti-Ir (10$\times$10$\textrm{cm}^2$) electrode and electrode distance was 2 cm, current density was $1.25 A/dm^2$, Obtained from the results of electrolytic oxidation experiments were not detected residual phenol. And then we knew about reaction time of electrolytic oxidation, current density, concentration of supporting electrolyte and electrode and electrode distance were 60 minutes, 1.25 A/dm$^2$, 1.0%, 2 cm.

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Physioelectrochemical Investigation of Electrocatalytic Activity of Modified Carbon Paste Electrode in Alcohol Oxidation as Anode in Fuel Cell

  • Shabani-Shayeh, Javad;Ehsani, Ali;Jafarian, Majid
    • Journal of the Korean Electrochemical Society
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    • v.17 no.3
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    • pp.179-186
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    • 2014
  • Methanol electro oxidation on the surface of carbon paste modified by $NiCl_2/6H_2O$ was studied in 1M NaOH by potentiostatic and potentiodynamic methods. Ni/C catalyst by the concentration of 5% Ni showed about twice higher electro catalytic activity than Ni metal. The amount of monolayer's on the surface of electrode is almost one order higher for Ni/C than Ni electrode. The kinetic parameters and the diffusion coefficient of methanol were derived from chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements.

LOW TEMPERATURE DEPOSITION OF SILICON OXIDE FILMS BY UV-ASSOSTED RF PLASMA-ENHANCED CVD

  • Hozumi, Atsushi;Sugimoto, Nobuhisa;Sekoguchi, Hiroki;Takai, Osamu
    • Journal of the Korean institute of surface engineering
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    • v.29 no.6
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    • pp.773-780
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    • 1996
  • Silicon oxide films were prepared by using five kinds of organosilicon compound as gas sources without oxygen by rf plasma-enhanced CVD (PECVD). UV light was irradiated on a substrate vertically during deposition to enhance film oxidation and ablation of carbon contamination in a deposited films. Films prepared with UV irradiation contained less carbon than those prepared without UV irradiation. The oxidation of the films was improved by UN irradiation. The effect of UV irradiation was, however, not observed when the films were prepared with tetramethy lsilane (TMS) which contained no oxygen atom. Dissociated oxygen atoms from an organosilicon compound were excited in the plasma with UV irradiation around the substrate surface and affected the enhancement of film oxidation and ablation of carbon in the films.

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Kinetics and Mechanisms of the Oxidation of Carbon Monoxide on Ni-Doped $\alpha-Fe_2O_3$

  • Kim, Keu-Hong;Jun, Jong-Ho;Choi, Jae-Shi
    • Bulletin of the Korean Chemical Society
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    • v.5 no.1
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    • pp.41-44
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    • 1984
  • The oxidation of carbon monoxide has been investigated on Ni-doped ${\alpha}-Fe_2O_3$ catalyst at 300 to $450^{\circ}$. The oxidation rates have been correlated with 1.5-order kinetics; first with respect to CO and 1/2 with respect to $O_2$. Carbon monoxide is adsorbed on lattice oxygen of Ni-doped ${\alpha}-Fe_2O_3$, while oxygen appears to be adsorbed on oxygen vacancy formed by Ni-doping. The conductivities show that adsorption of CO on O-lattice produces conduction electron and adsorption of $O_2$ on O-vacancy withdraws the conduction electron from vacancy. The adsorption process of CO on O-lattice is rate-determining step and dominant defect of Ni-doped ${\alpha}-Fe_2O_3$ is suggested from the agreement between kinetic and conductivity data.

Catalytic CO Oxidation Over Ni Films Supported by Carbon Fiber

  • Seo, Hyun-Ook;Nam, Jong-Won;Kim, Kwang-Dae;Kim, Young-Dok;Lim, Dong-Chan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.266-266
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    • 2012
  • Ni films with a thickness of 700-800 nm were deposited on carbon fiber layers using electroless deposition, and surface structures and chemical properties of these films with various annealing temperatures (300, 600 and $900^{\circ}C$) were studied. $600^{\circ}C$-annealing under atmospheric conditions resulted in formation of porous surface structures with a mean pore size of ~100 nm, whereas the other samples showed non-porous surface structures. $600^{\circ}C$-annealed Ni film showed much higher reactivities for toluene adsorption and CO oxidation comparing to other non-porous surfaces.

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Analysis and Measurement on Failure Behavior off Scales by Acoustic Emission Method (Scale 파괴거동 측정 및 해석)

  • Choi Jin Won;TANIGUCHI S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.330-331
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    • 2005
  • It was found possible to evaluate the temperature at which major scale failure takes place during cooling by installing a most modem acoustic emission(AE) analytical system. Ultra low carbon steel and low carbon steels containing a few minor alloying elements were oxidized in air at 900, 1050 and $1200^{\circ}C$ for 20 min, and then cooled in vacuum at 30, 70 and $110^{\circ}C/min$. The significance of the present research is the evaluation of the spallation temperature and thus the calculation of apparent thermal stress for scale spallation using the difference between oxidation temperature and spallation temperature. They were assessed as 0.22 to 0.68, 0.45 to 1.80, and 0.65 to 1.95 GPa for oxidation at 900, 1050 and $1200^{\circ}C$, respectively.

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Electron Transport System for Carbon Monoxide Oxidation in Acinetobacter sp.1 (Acinetobacter sp.1의 일산화탄소 산화를 위한 전자전달계)

  • 김영민;조진원
    • Korean Journal of Microbiology
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    • v.24 no.1
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    • pp.46-50
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    • 1986
  • Experiments with particulate fractions of Acinetobacter sp. 1 revealed that coeuzyme $Q_{10}$ is not the physiolohical electron acceptor, and that cytochromes of a, b, c, and o types are found in cells grown with carbon monoxide (CO) as the sole source of carbon and energy. It was found that cytochromes of b and o types, but not the a and c types, are functional in CO oxidation. Nicotinamide adenine dinucleotide (phosphate) is not involved in CO oxidation.

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Erosion Behavior of SiC Coated C/C Composites with Condition of Combustion Test

  • Joo, Hyeok-Jong;Min, Kyung-Dae;Lee, Jae-Won
    • Carbon letters
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    • v.4 no.3
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    • pp.133-139
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    • 2003
  • Carbon/carbon composites are ideal candidates for a number of aerospace applications including structural materials for advanced vehicles, leading edges, structures of re-entry and hypersonic vehicles and propulsion systems. One serious defect for such application of the carbon/carbon composites is their poor oxidation resistance in high temperature oxidizing environments. SiC coating was employed to protect the composites from oxidation. It is mechanically and chemically stable under extreme thermal and oxidative environments, provides good adhesion to the substrate, and offers good thermal shock resistance. The SiC layer on the nozzle machined from the carbon/carbon composites was formed by pack-cementation method. Then, erosion characteristic of SiC coated carbon/carbon nozzle was examined by combustion test using a liquid rocket motor. The erosion rates were measured as function of combustion pressure, ratio of oxygen to fuel, combustion time, density of the composites and geometry of reinforced carbon fibre in the composites. The morphology change of the composites after combustion test was investigated using SEM and erosion mechanism also was discussed.

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Mechanical Properties of Unidirectional Carbon-carbon Composites as a Function of Fiber Volume Content

  • Dhakate, S.R.;Mathur, R.B.;Dham, T.L.
    • Carbon letters
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    • v.3 no.3
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    • pp.127-132
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    • 2002
  • Unidirectional polymer composites were prepared using high-strength carbon fibers as reinforcement and phenolic resin as matrix precursor with keeping fiber volume fraction at 30, 40, 50 and 60% respectively. These composites were carbonized at $1000^{\circ}C$ and graphitised at $2600^{\circ}C$ in the inert atmosphere. The carbonized and graphitised composites were characterized for mechanical properties as well as microstructure. Microscopic studies were carried out of the polished surface of carbonized and graphitised composites after etching by chromic acid, to understand the effect of fiber volume fraction on oxidation at fiber-matrix interface. It is found that the flexural strength in polymer composites increases with fiber volume fraction and so does for the carbonised composites. However, the trend was found to be reversed in graphitised composites. In all the carbonized composites anisotropic region has been observed at fiber-matrix interface which transforms into columnar type microstructure upon graphitisation. The extension of strong and weak columnar type microstructure is function of fiber volume fraction. SEM microscopy of the etched surface of the sample reveal that composites containing 40% fiber volume has minimum oxidation at the interface, revealing a strong interfacial bonding.

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