• Title/Summary/Keyword: Oxidation stress

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Stress-assisted oxidation behaviour of inconel 52M/316 austenitic stainless-steel dissimilar weld joints in a simulated pressurised water reactor

  • Xu, Youwei;Yang, Binhui;Shi, Yu
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3778-3787
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    • 2022
  • The stress-assisted oxidation behaviour of Inconel 52 M/316 austenitic stainless-steel (SS) dissimilar weld joints (DMWJ) in a simulated pressurised water reactor environment was investigated. A corrosion galvanic couple formed between the Inconel 52 M and 316 SS due to differences in their nonferrous metal content. The electric field from the corrosion couple attracted metal cations (e.g. Fe2+, Cr3+) to the Inconel 52 M that were deposited as FeCr2O4. An additional corrosion galvanic couple was generated due to variations in the plastic deformation of the DMWJ. The superposition of electric fields from the different couples resulted in ridge-like oxide depositions in the fusion zone.

The Role of Meat Protein in Generation of Oxidative Stress and Pathophysiology of Metabolic Syndromes

  • Ahmad, Muhammad Ijaz;Ijaz, Muhammad Umair;Haq, Ijaz ul;Li, Chunbao
    • Food Science of Animal Resources
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    • v.40 no.1
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    • pp.1-10
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    • 2020
  • Various processing methods have a great impact on the physiochemical and nutritional properties of meat that are of health concern. Hence, the postmortem processing of meat by different methods is likely to intensify the potential effects on protein oxidation. The influence of meat protein oxidation on the modulation of the systemic redox status and underlying mechanism is well known. However, the effects of processed meat proteins isolated from different sources on gut microbiota, oxidative stress biomarkers, and metabolomic markers associated with metabolic syndromes are of growing interest. The application of advanced methodological approaches based on OMICS, and mass spectrometric technologies has enabled to better understand the molecular basis of the effect of processed meat oxidation on human health and the aging process. Animal studies indicate the involvement of dietary proteins isolated from different sources on health disorders, which emphasizes the impact of processed meat protein on the richness of bacterial taxa such as (Mucispirillum, Oscillibacter), accompanied by increased expression of lipogenic genes. This review explores the most recent evidences on meat processing techniques, meat protein oxidation, underlying mechanisms, and their potential effects on nutritional value, gut microbiota composition and possible implications on human health.

Electrical and Mechanical Properties of Semiconductive Shield in Power Cable; Volume Resistivity and Stress-Strain Measurement (전력케이블내 반도전 재료의 전기적 및 기계적 특성; 체적저항과 Stress-Strain 측정)

  • Lee Kyoung-Yong;Yang Jong-Seok;Choi Yong-Sung;Park Dae-Hee
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.2
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    • pp.45-50
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    • 2005
  • To improve mean-life and reliability of power cable, in this study, we have investigated electrical properties and stress-strain showing by changing the content of carbon black that is semiconductive additives for underground power transmission. Specimens were made of sheet form with the nine of specimens for measurement. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the pre-heated oven of both 25±1 [℃] and 90±1 [℃]. And stress-strain of specimens was measured by TENSOMETER 2000. A speed of measurement was 200[mm/min], ranges of stress and strain were 400[Kgf/㎠] and 600[%]. In addition tests of stress-strain were progressed by aging specimens in air oven. From this experimental results, volume resistivity was high according to increasing the content of carbon black. And yield stress was increased, while strain was decreased according to increasing the content of carbon black. And stress-strain were decreased some after aging because of oxidation reaction of chemical defect. We could know EEA was excellent more than other specimens from above experimental results.

SREBP-1c Ablation Protects Against ER Stress-induced Hepatic Steatosis by Preventing Impaired Fatty Acid Oxidation (지방산 산화 장애 제어를 통한 SREBP-1c 결핍의 소포체 스트레스 유발 비알콜성지방간 보호작용)

  • Lee, Young-Seung;Osborne, Timothy F.;Seo, Young-Kyo;Jeon, Tae-Il
    • Journal of Life Science
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    • v.31 no.9
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    • pp.796-805
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    • 2021
  • Hepatic endoplasmic reticulum (ER) stress contributes to the development of steatosis and insulin resistance. The components of unfolded protein response (UPR) regulate lipid metabolism. Recent studies have reported an association between ER stress and aberrant cellular lipid control; moreover, research has confirmed the involvement of sterol regulatory element-binding proteins (SREBPs)-the central regulators of lipid metabolism-in the process. However, the exact role of SREBPs in controlling lipid metabolism during ER stress and its contribution to fatty liver disease remain unknown. Here, we show that SREBP-1c deficiency protects against ER stress-induced hepatic steatosis in mice by regulating UPR, inflammation, and fatty acid oxidation. SREBP-1c directly regulated inositol-requiring kinase 1α (IRE1α) expression and mediated ER stress-induced tumor necrosis factor-α activation, leading to a reduction in expression of peroxisome proliferator-activated receptor γ coactivator 1-α and subsequent impairment of fatty acid oxidation. However, the genetic ablation of SREBP-1c prevented these events, alleviating hepatic inflammation and steatosis. Although the mechanism by which SREBP-1c deficiency prevents ER stress-induced inflammatory signaling remains to be elucidated, alteration of the IRE1α signal in SREBP-1c-depleted Kupffer cells might be involved in the signaling. Overall, the results suggest that SREBP-1c plays a crucial role in the regulation of UPR and inflammation in ER stress-induced hepatic steatosis.

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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Thermal Oxidation of Porous Silicon (다공질 실리콘 (Porous Silicon) 의 열산화)

  • Yang, Cheon-Soon;Park, Jeong-Yong;Lee, Jong-Hyun
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.10
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    • pp.106-112
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    • 1990
  • The progress of oxidation of a porous silicon layer(PSL) was studied by examining the temperature dependence of the oxidation and the infrared absorption spectra. Thick OPSL(oxidized porous silicon layer). which has the same properties as thermal $SiO_{2}$ of bulk silicon, is formed in a short time by two steps wet oxidation of PSL at $700^{\circ}C$, 1 hr and $1100^{\circ}C$, 1 hr. Etching rate, breakdown strength of the OPSL are strongly dependent on the oxidation temperature, oxidation atmosphere. And its breakdown field was ${1\MV/cm^-2}$ MV/cm The oxide film stress was determined through curvature measurement using a dial gauge. During oxidation at temperature above $1000^{\circ}C$ in dry $O_{2}$, stress on the order of ${10^9}\dyne/{cm^2}{-10^10}\dyne/{cm^2}$ are generated in the OPSL.

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The Analysis of Three-dimensional Oxidation Process with Elasto-viscoplastic Model

  • Lee Jun-Ha;Lee Hoong-Joo
    • Transactions on Electrical and Electronic Materials
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    • v.5 no.6
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    • pp.215-218
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    • 2004
  • This paper presents a three-dimensional numerical simulation for thermal oxidation process. A new elasto-viscoplastic model for robust numerical oxidation simulation is proposed. The three-dimensional effects of oxidation process such as mask lifting effect and corner effects are analyzed. In nano-scale process, the oxidant diffusion is punched through to the other side of the mask. The mask is lifted so the thickness of oxide region is greatly enhanced. The compressive pressure during the oxidation is largest in the mask corner of the island structure. This is because the masked area near the corner is surrounded by an area larger than the others in the island structure. This stress induces the retardation of the oxide growth, especially at the masked corner in the island structure.

Effects of Surface Deformation on Intergranular Oxidation of Alloy 600 (Alloy 600의 결정립계 산화에 대한 표면 변형의 영향)

  • Ha, Dong Woog;Lim, Yun Soo;Kim, Dong Jin
    • Corrosion Science and Technology
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    • v.19 no.3
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    • pp.138-145
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    • 2020
  • Immersion tests of Alloy 600 were conducted in simulated primary water environments of a pressurized water reactor at 325 ℃ for 10, 100, and 1000 h to obtain insight into effects of surface deformation on internal and intergranular (IG) oxidation behavior through precise characterization using various microscopic equipment. Oxidized samples after immersion tests were covered with polyhedral and filamentous oxides. It was found that oxides were abundant in mechanically ground (MG) samples the most. The number density of surface oxides increased with time irrespective of the method of surface finish. IG oxidation occurred in mechanically polished (MP) and chemically polished (CP) samples with thin internal oxidation layers. However, IG oxidation was suppressed with relatively thick internal oxidation layers in MG samples compared to MP and CP samples, suggesting that MG treatment could increase resistance to primary water stress corrosion cracking (PWSCC) from the standpoint of IG oxidation. As a result, appropriate surface treatment for Alloy 600 could prevent oxygen diffusion into grain boundaries, inhibit IG oxidation, and finally induce its high PWSCC resistance.

Effects of Malvae Semen and Abutili Semen on Anti-oxidation Activities (동규자(冬葵子)와 경마자의 항산화(抗酸化) 효능(效能) 연구(硏究))

  • Choi, Jung-Woon;Seong, Nak-Sull;Lee, Young-Jong
    • The Korea Journal of Herbology
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    • v.21 no.4
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    • pp.159-170
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    • 2006
  • Objectives : Anti-oxidation activities of Malvae Semen and Abutili Semen were compared and evaluated. Methods : We tested the anti-oxidant effect through in vitro experiment and in vivo experiment that induced oxidative stress using ethanol. Results : 1. In the anti-oxidative activities of Malvae Semen and Abutili Semen they had high effects in case of the scavenging activitie of DPPH and superoxide anion radical, and inhibitory effect of linoleic acid oxidation. 2. Malvae Semen had large quantities of phenolic compound than Abutili Semen, but the anti-oxidative activity of Malvae Semen was weaker than that of Abutili Semen. 3. The anti-oxidative effect of Abutili Semen was more strong than that of Malvae Semen in the rat stressed by ethanol. Conclusion : Anti-oxidation activities of Abutili Semen were stronger than those of Malvae Semen. Therefore, the complementary usage of Malvae Semen and Abutili Semen can be considered.

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Si-buffer pinholes in the SEPOX (selective poly oxidation) process (SEPOX (selective poly oxidation) process에서 Si-buffer layer에 발생하는 pinhole 현상에 대한 연구)

  • 윤영섭
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.6
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    • pp.151-157
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    • 1996
  • We propose a mechanism for the formation of pinholes in the Si-buffer layer, through the observations with varying the process- and structure variables in the SEPOX (selective poly-oxidation) process, an isolation method for sub-u DRAMs. Pinholes are formed through the accumulation of Si vacancies generated by the oxidation of Si, in which Si atoms leave the sites (vacancies) at the Si/SiO$_{2}$ interfaces and diffuse into the oxide to be oxidized near interface. In the course of the accumulation of Si-vacancies, the stress induced in the Si-buffer layer affects the migration of vacancies to result in the final size and distribution of pinholes. This paper may be, to our knowledge, the first report about the oxidation-induced pinhole in the Si/SiO$_{2}$ system.

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