• Title/Summary/Keyword: Damage mechanism

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Effects of Low Level Laser Treatment at LR2 and LR8 acupoint on the liver damage induced in D-GalN in rats (간경(肝經)의 형화혈(滎火穴)과 합수혈(合水穴)에 시술한 레이저침이 D-GalN 간손상 유발 흰쥐에 미치는 영향)

  • Kim, Wang-In;Youn, Dae-Hwan;Choi, Chan-Hun;Na, Chang-Su
    • Korean Journal of Acupuncture
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    • v.29 no.1
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    • pp.131-141
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    • 2012
  • Objectives : This study was performed to investigate the effect of invasive laser acupuncture treatment at Liver Brook (LR2) acupoint and Liver Sea (LR8) acupoint on liver damage induced by D-galactosamine (D-GalN) in rats Methods : Liver damage was induced by D-GalN. The experimental rats were divided into two groups (control group, Low Level Laser Treatment (LLLT) group). Control groups were classified into small groups. Intact group had no liver damage and no treatment. D-GalN group was induced liver damage induced by D-GalN and not treated. LLLT group were induced liver damage induced by D-GalN and then treated at the LR2 or LR8 acupoint with 532, 658, 904 nm invasive laser acupuncture. The treatment was carried out three days at a time for 15days at both acupoints. To examine mechanism of the effect of invasive laser acupuncture, we measured the contents of ASP, ALT, ALP, TBIL in serum, CBC in blood and SOD in liver tissue. Results : The change of body weight increased in all groups. That change was AST and ALP, the AST activity decreased significantly compared with the control groups and decreased by 532 nm and 904 nm both LLLT groups. But ALP increased at LR8 acupoint by 658 nm. TBIL level significantly decreased in all LLLT groups. The SOD of LLLT groups increased in the liver tissue of rats compared to the control groups. SOD activity indicated that LLLT can help cellular defense mechanism by preventing scavenging hydrogen peroxide. In the change of WBC, it was increased in D-GalN Control group compared to intact group and LLLT groups. Conclusions : These results suggested that invasive laser acupuncture treatment at LR2 or LR8 acupoint reduced activation of hepatic enzyme and damage of liver tissue. Thus, the effect of invasive laser acupuncture was nearly identical to the way of the traditional acupuncture for the treatment of hepatocytotoxicity.

The vibration impact assessment for long-term damage mechanism of a pump (펌프 장기손상 메커니즘 규명을 위한 진동영향 평가)

  • Kim, T.H.;Kim, H.S.;Kim, D.K.;Kim, W.T.;Han, B.S.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.10a
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    • pp.441-445
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    • 2009
  • The most of the goals of pump designers and users are efficient operation and productivity. But the safety-grade pumps in nuclear power plants are needed to operate continuously for an essential condition of system operation. Also, most of the rules and regulatory standards that have been prepared for nuclear pumps are dedicated to achieve public safety. The study examined pump vibration in a pump outlet flow and distinguished the regions of pump vibration frequency cause by cavitation and recirculation. The study made a counterproposal in determination of pump outlet flow so that the discharge flow will be able to minimize the long-term damage of the pump.

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3D TCAD Analysis of Hot-Carrier Degradation Mechanisms in 10 nm Node Input/Output Bulk FinFETs

  • Son, Dokyun;Jeon, Sangbin;Kang, Myounggon;Shin, Hyungcheol
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.2
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    • pp.191-197
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    • 2016
  • In this paper, we investigated the hotcarrier injection (HCI) mechanism, one of the most important reliability issues, in 10 nm node Input/Output (I/O) bulk FinFET. The FinFET has much intensive HCI damage in Fin-bottom region, while the HCI damage for planar device has relatively uniform behavior. The local damage behavior in the FinFET is due to the geometrical characteristics. Also, the HCI is significantly affected by doping profile, which could change the worst HCI bias condition. This work suggested comprehensive understanding of HCI mechanisms and the guideline of doping profile in 10 nm node I/O bulk FinFET.

Surgical treatment for dysesthesia after overfilling of endodontic material into the mandibular canal (하치조신경관으로 과충전된 근관치료 충전재에 의한 감각이상의 외과적 처치)

  • Song, Jae-Min;Kim, Yong-Deok;Lee, Jae-Yeol
    • The Journal of the Korean dental association
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    • v.54 no.11
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    • pp.874-879
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    • 2016
  • Damage to the inferior alveolar nerve(IAN) is a relatively infrequent complication in endodontic treatment. However, endodontic overfilling involving the mandibular canal may cause an injury of the inferior alveolar nerve resulting in sensory disturbances such as pain, dysesthesia, paresthesia or anesthesia. Two mechanism(chemical neurotoxicity and mechanical compression) are responsible for the IAN injury. When absorbent materials overfilled, it can be treated as a non-surgical procedure. But early surgical intervention required when mechanical, chemical nerve damage expected. We report surgical removal of overfilled gutta-percha and IAN decompression through sagittal split osteotomy in case of dysesthesia after overfilling of endodontic material into the mandibular canal. Dysesthesia recovered 3 months after surgical treatment.

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Ozone resistance of radiosensitive strains of escherichia coli K-12 (Escherichia coli K-12 방사선 감수성 균주의 오존 내성)

  • Harvey, Michel
    • Korean Journal of Microbiology
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    • v.26 no.2
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    • pp.113-121
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    • 1988
  • Ozone, an atmospheric pollutant, can damage similar UV and X-rays DNA and its components. It is possible then that the KNA damage produced by this gas are similar, to some extent, to those of radiations and that they could be repaired by the same DNA repair mechanisms. It has been observed in Escherichia coli that radiosensitive strains such as lex A, rec A and pol A, all deficient to some extent for DNA repair, are more sensitive to ozone than a wild type strain. We have thendetermined the ozone resistance and host-cell reactivation of ozone-damaged T3 phages for the E. coli double mutants pol A, lex A, uvr B, lex A, uvr A, rec A and rec A lox A. According to the results, the DNA polymerase 1 plays a key role in ozone resistance and Type 11 mechanism and/or shory patch excision repair are the most important for it. The interactions between the different DNA repair mechanisms are secondary. There is a strong correlation between ozone resistance and the capacity to reactivate T3 phages damaged by ozone.

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Radioprotection of Alliin in Oogenesis Cells of a White Rat (흰쥐 난자형성 세포의 알리인 방어효과)

  • JI, Tae-Jeong
    • Journal of radiological science and technology
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    • v.41 no.5
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    • pp.471-478
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    • 2018
  • Oogenesis process of ovary produces a lot of undifferentiated cells. Especially, the radiation exposure of early immature cells in the process of growth to oocyte causes serious disabilities. This study examined the radiation damage mechanism of undifferentiated cells and organelles in oogenesis process, and the radioprotection after injection of alliin. The ultrastructure after 7Gy X-ray irradiation on the white rat was observed in the experiment. The results is as follows. It was observed that the nucleus membrane of an oogonium was damaged and vacuolated in the several parts after 15 days of irradiation. The damage of mitochondria membrane and flow in cytoplasm after 20 and 30 days was found in the oogonium. After 40 days observation, peroxidation of fat droplets was found and organelles were tangled each other in ovary tissue. The partial damage of nuclear membrane in oogonium past 15 days after injection of alliin was found, but decreased remarkably. Mitochondria, Golgi body, and rough endoplasmic reticulum were also clearly observed, therefore, radioprotection effects in alliin was confirmed partially.

Low Cycle Fatigue Behavior of 12Cr Steel for Thermal Power Plant Steam Turbine (화력발전소 증기터빈용 12Cr 강의 저주기 피로거동)

  • Kang, Myeong-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.8
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    • pp.71-76
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    • 2002
  • In this study low cycle fatigue (LCF) behavior of 12Cr steel at high temperature are described. Secondly, comparisons between predicted lives and experimental lives are made for the several sample life prediction models. Two minute hold period in either tension or compression reduce the number of cycles to failure by about a factor of two. Twenty minute hold periods in compression lead to shorter lives than 2 minute hold periods in compression. Experiments showed that life predictions from classical phenomenological models have limitations. More LCF experiments should be pursued to gain understanding of the physical damage mechanisms and to allow the development of physically-based models which can enhance the accuracy of the predictions of components. From a design point-of-view, life prediction has been judged acceptable for these particular loading conditions but extrapolations to thermo-mechanical fatigue loading, for example, require more sophisticated models including physical damage mechanisms.

Effect of reducing tsunami damage by installing fairing in Kesen-Bridge

  • Abukawa, Takahiro;Nakamura, Yuto;Hasegawa, Akira
    • Earthquakes and Structures
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    • v.7 no.6
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    • pp.1045-1060
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    • 2014
  • The 2011 off the Pacific coast of Tohoku Earthquake brought serious damage around the Tohoku district in Japan, and much human life and fortune were lost. Bridges were damaged by this earthquake. It was the most serious damage that the superstructures of bridges were flowed out by tsunami. Earthquakes of the same scale are predicted in other areas of Japan. It is necessary to take measures for bridges near coast. In order to understand the tsunami force acting on the bridge, hydraulic model experiments was conducted. In addition, this paper focused on fairing that is effective in wind resistant stability. Installing fairing to bridges has been verified by experiments whether it is possible to reduce the force of tsunami.

Study on the Characteristics of Cavitation Erosion-Corrosion for Mild Steel ( 2 ) - Damage Behaviour of Vibration Cavitation Erosion-Corrosion - (연강의 캐비테이션 침식-부식 특성에 관한 연구 ( 2 ) - 진동 캐비테이션 침식-부식 손상 거동 -)

  • Hwang, Jae-Ho;Lim, Uh-Joh
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.3
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    • pp.302-309
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    • 1996
  • Cavitation erosion-corrosion implies damage to materials due to the shock pressure or shock wave that results when bubbles form and collapse at a metal surface within a liquid. If the liquids corrosive to the material, a condition typically encountered in industry, the component materials may suffer serious damage by a combination of mechanical and electrochemical attack. To suppress cavitation erosion as well as cavitation erosion-corrosion to hydraulic equipments, innovations such as the improvement in the geometric design of the equipment or the selection of suitably resistant construction materials are necessary. This study was tested by using the piezoelectric vibrator with 20kHz, 24${\mu}$m for cavitation generation. And also, the vibratory cavitation erosion-corrosion tests on commercial mild steel SS41were carried out. We carefully observed the erosion pattern and surface photography. The geometrical mechanism of pit growth, which is to be likely these processing; shallow typelongrightarrowundercut typelongrightarrowwide shallow type.

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Development of Progressive Collapse Analysis Program considering Dynamic Effects (동적효과를 고려한 연쇄붕괴해석 프로그램의 개발)

  • Kim, Jin-Koo;Park, Jun-Hee;An, Da-Woon;Kim, Hyun-Su
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.771-776
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    • 2007
  • Widespread propagation of failure can be triggered by localized damage to a structure because of fires, impact and explosion etc. In this paper, the progressive collapse analysis program is developed to automatically check the failed members and construct the modified structural model at each step. OpenSees, that is widely used in many research groups, was used for the developed progressive collapse analysis control program. The control program developed in this study automatically computes the damage indices of all the structural members and performance a progressive collapse analysis after the first failed member is selected. Using the developed program, we compared the progressive collapse behaviors of the example structures considering dynamic effects or not, and the difference of progressive collapse mechanism according to the modeling method of the failed members.

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