• 대한전기학회논문지
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• 제41권7호
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• pp.802-808
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• 1992

To investigate degradation procedure and life time of the oxidized PE and the unoxidized PE, alternative voltage is applied to the CIGRE Method-II (CM-II) electrode system, which is loaded artificial void, and measures the distribution of partial discharging generation. From the results, the samples etched by oxidation had wide degradation area of dielectric strength. Furthermore, discharge starting voltage was shifted to low voltage, the discharge generation frequency was high and consequently, the quantity of mean charge becomes small. Also, life time of the oxdized sample is shortened according as the oxidation time is longer.

• 한국재료학회지
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• 제18권12호
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• pp.645-649
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• 2008

Graphite for the nuclear reactor is used to the moderator, reflector and supporter in which fuel rod inside of nuclear reactor. Recently, there are many researches has been performed on the various characteristics of nuclear graphite, however most of them are restricted to the structural and the mechanical properties. Therefore we focused on the thermal property of nuclear graphite. This study investigated the thermal emissivity following the oxidation degree of nuclear graphite with IG-11 used as a sample. IG-11 was oxidized to 6% and 11% in air at 5 l/min at $600^{\circ}C$. The porosity and thermal emissivity of the sample were measured using a mercury porosimeter and by an IR method, respectively. The thermal emissivity of an oxidized sample was measured at $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$, $400^{\circ}C$ and $500^{\circ}C$. The porosity of the oxidized samples was found to increase as the oxidation degree increased. The thermal emissivity increased as the oxidation degree increased, and the thermal emissivity decreased as the measured temperature increased. It was confirmed that the thermal emissivity of oxidized IG-11 is correlated with the porosity of the sample.

• Mass Spectrometry Letters
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• 제3권1호
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• pp.10-14
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• 2012

Artificially oxidized cysteine residues in peroxiredoxin 6 (Prx6) were detected by electrospray interface capillary liquid chromatography-linear ion trap mass spectrometry after the preparation of two-dimensional gel electrophoresis (2D-GE). We used Prx6 as a model protein because it possesses only two cysteine residues at the 47th and 91st positions. The spot of Prx6 on 2D-GE undergoes a basic (isoelectric point, pI 6.6) to acidic (pI 6.2) shift by exposure to peroxide due to selective overoxidation of the active-site cysteine Cys-47 but not of Cys-91. However, we detected a tryptic peptide containing cysteine sulfonic acid at the 47th position from the basic spot and a peptide containing both oxidized Cys-47 and oxidized Cys-91 from the acidic spot of Prx6 after the separation by 2D-GE. We prepared two types of oxidized Prx6s: carrying oxidized Cys-47 (single oxidized Prx6), and other carrying both oxidized Cys-47 and Cys-91 (double oxidized Prx6). Using these oxidized Prx6s, the single oxidized Prx6 and double oxidized Prx6 migrated to pIs at 6.2 and 5.9, respectively. These results suggest that oxidized Cys-47 from the basic spot and oxidized Cys-91 from the acidic spot are generated by artificial oxidation during sample handling processes after isoelectric focusing of 2D-GE. Therefore, it is important to make sure of the origin of cysteine oxidation, if it is physiological or artificial, when an oxidized cysteine residue(s) is identified.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1185-1194
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• 2022

The maintenance of condenser main pipe is the key to achieve film-forming amine maintenance effectiveness. In this work, oxygen content, pH and temperature of the solution were controlled to simulate the condition of condenser main pipe, and magnetite coated carbon steel sample was prepared by pre-oxidization. CAM was used to characterize the hydrophobicity of film formed samples. Hydrophobic film was formed on pre-oxidized carbon steel samples when octadecylamine concentration reaches 20 mg/kg. SEM, EDS, EIS, and PD were used to characterize the influence of octadecylamine concentration on maintenance effectiveness. It was found that the maintenance effectiveness was enhanced and the corrosion rate was suppressed with the increase of octadecylamine concentration. FIB and TEM were used to detect the adsorbed octadecylamine film thickness founding that octadecylamine adsorbed onto the surface of pre-oxidized carbon steel by multi-layer adsorption mechanism.

• 청정기술
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• 제19권4호
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• pp.453-458
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• 2013

배기가스 중에서 비산재는 수은을 산화하거나 흡착하는 능력을 지닌다. 비산재의 수은 산화 및 흡착 효율은 비산재가 가지는 특성에 따라 변하여 일정하지 않다. 본 연구는 비산재 성분과 수은의 반응특성을 이해하기 위하여 비산재 성분물질이 원소수은과 산화수은에 대해 가지는 산화 및 흡착 능력을 평가하였다. 그리고 비산재 시료의 조성에 맞게 합성한 비산재를 시험하였고, 석탄화력발전소에서 수령한 비산재 시료의 결과와 비교하였다. 원소수은에 대해서는 미세탄소분말, 산화구리, 산화철이 높은 산화 또는 흡착효율을 보였고, 염화수은에 대해서는 미세탄소분말, 산화칼슘, 산화구리, 산화마그네슘이 높은 효율을 보였다. 그리고 합성비산재는 비산재 시료와 유사한 수은 산화 및 흡착 효율을 보였다.

• Carbon letters
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• 제12권1호
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• pp.1-7
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• 2011

In the present study, the removal of Pb (II) ions on oxidized activated carbons (ACs) was investigated. ACs were derived from activation of indigenous cotton stalks waste with potassium hydroxide (KOH) in two-stage process. The KOH-ACs were subjected to liquid-phase oxidation with hot $HNO_3$ and one untreated sample was included for comparison. The obtained carbons were characterized by Fourier transform infrared (FTIR), slurry pH and $N_2$-adsorption at 77 K, respectively. Adsorption capacity of Pb (II) ions on the resultant carbons was determined by batch equilibrium experiments. The experimental results indicated that the oxidation with nitric acid was associated with a significant increase in mass of yield as well as a remarkable reduction in internal porosity as compared to the untreated carbon. The AC-800N revealed higher adsorption capacity than that of AC-800, although the former sample exhibited low surface area and micropore volume. It was observed that the adsorption capacity enhancement attributed to pore widening, the generation of oxygen functional groups and potassium containing compounds leading to cation-exchange on the carbon surface. These results show that the oxidized carbons represented prospective adsorbents for enhancing the removal of heavy metals from wastewater.

• 한국식품과학회지
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• 제33권2호
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• pp.216-220
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• 2001

이 연구에서는 산화 셀룰로오스가 케이크 등과 같은 식품에서 식이섬유 소재로 사용될 수 있는지 그 가능성을 조사하기 위하여, TEMPO, NaBr 및 NaOCl을 동시에 사용하여 셀룰로오스 내의 1차 알코올기를 산화시키고, 산화 셀룰로오스를 밀가루 함량의 10%수준으로 대체하여 제조한 케이크의 이화학적 및 관능적 특성을 평가하였다. 그 결과 산화 셀룰로오스를 함유한 케이크는 산화 셀룰로오스를 첨가하지 않은 대조군보다 전체적으로 색이 어둡고 노란색이 강하였으나, 전체적인 부피는 증가하는 것으로 나타났다. 관능적 평가 결과 셀룰로오스를 첨가한 케이크는 가루끼 특성이 강하게 나타난 반면, 산화 셀룰로오스를 첨가한 케이크는 대조군과 가루끼 특성에서는 유의적인 차이를 보이지 않았고, 단단한 정도는 적고 촉촉한 정도는 더 크게 나타나, 산화 셀룰로오스를 케이크에 첨가시 텍스처 특성이 오히려 향상되는 것으로 나타났다. 이 실험 결과 산화 셀룰로오스는 케이크에서 외관이나 텍스처 특성의 저하없이 식이섬유 소재로 사용될 수 있음을 알 수 있었다.

• 약학회지
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• 제22권3호
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• pp.157-162
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• 1978

Total organic carbon(TOC) can be determined by means of combustion and flame ionization detector. The principle of string method is that a sample acidified to pH2 and transferred into combustion tube by string is oxidized with air. Another combustion tube method is that organic compounds are oxidized in the combustion tube charged with CuO and cobalt asbestos after the acidified sample is injected directly by microsyringe. Carbon dioxide evolved was reduced under specially treated nickel catalyst and hydrogen, the methane produced was detected by flame ionization detector. Linear relationship was found between concentration and the peak height by the string method. The peak area in the case of combustion tube method is in the range of 1-200ppm. The coefficient of variation by string method was 2.3% and that by combustion tube method was 1.8%. The lower detectable limit was about 10mol. Advantages of the latter are simplicity, sensitivity and reproducibility. TOC in contineous stream can also be determined automatically by means of the string method.

• Carbon letters
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• 제2권3_4호
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• pp.170-175
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• 2001

A petroleum-based isotropic pitch fiber spun by melt-blown method was oxidized in air flow at various conditions. The oxidized pitch fiber obtained was tested for its infusibility and its elemental composition during the process of stabilization. The structural changes were traced by using solvent solubility, FT-IR spectroscopy, and elemental analysis. The samples showed a gradual increase in weight with increasing the oxidization temperature. The weight gain of sample oxidized at $320^{\circ}C$ for 10 min was about 4.5%. The concentration of the pyridine and toluene soluble fraction decreased with an increase in stabilization temperatures. The oxygen uptaken in the stabilization process converted aliphatic side chains into the carbonyl groups. As stabilization proceeded, the more ether and carboxylic acid groups were formed through the oxidations of aldehyde and primary alcohol, and then the carboxylic acid was dehydrated to be aromatic anhydride.

• 동아시아식생활학회지
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• 제5권1호
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• pp.87-93
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• 1995

The oxidized mixture of lipid(methyl linoleate) and phenolics(phloroglucinol) at 37$^{\circ}C$, 82$m\ell$ O/min., for 9 days were separated each by C cartridge and silica cartridge making use of different eluting solvent. And the oxidation products were analyzed by HPLC. In conclusion, the oxidized mixture were separated into methyl linoleate and phloroglucinol by cartridge on HPLC. and also in this experiment, separated methyl linoleate and phloroglucinol could be analyzed in the common eluant, water and acetonitrile on HPLC. SEP-PAK cartridges were used almost sample purification until now, but under the various eluting solvents and conditions, cartridge will be expected to mini columns which can separate different polarity materials.