• 제목/요약/키워드: internal damage

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고속철도 궤도구성품의 손상유형 표준화 (The Standardization of Damage Types of Track Components on High Speed Railway)

  • 오승재;성덕룡;김준형;박용걸
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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    • pp.1056-1064
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    • 2008
  • It is estimated that the running of locally-developed next generation High Speed Trains with maximum speed of 400km/h will help to deteriorate track components. It was presented rail defect coding system in UIC 712R includes the definitions of damage types of rail, maintenance procedures, and etc to detect and maintain. It is necessary to make a track maintenance manual determining track maintenance periods using the standardization of damage types of track components such as: sleeper, fastener, elastic pad. In this paper, the damage types of high speed track components are investigated by referring domestic and foreign literatures. And then the damage types of rail given in UIC 712R is reclassified more particularly and classified damage types of track components using internal high speed railway. In conclusion, this paper suggests standardization for damage types of track components on internal high speed railway.

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이동원(李東垣)의 풍약(風藥) 활용법(活用法)에 대한 고찰 (A Research on Li Dong-yuan's Application Rule of Wind Herbs(風藥))

  • 신상원
    • 대한한의학원전학회지
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    • 제31권4호
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    • pp.1-16
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    • 2018
  • Objectives : The paper studies the epistemology of Wind Herbs, its origin, its drug category and medicinal property, attempted to understand Lidongyuan's framework of mechanism of internal damage and treatment principle, and why he used it from his viewpoint. Methods : His suggestion was based on this treatment of internal damage suing wind herbs. Therefore, it cannot be viewed as a simple herbological concept. It rather displays the characteristics of medication based on clinical pathology. Therefore, wind herb should be comprehensively understood from the understanding of the mechanism of internal damage. That is why the paper studied around Piweilun, where Lidongyuan's concept on internal damage is established with finality. Additionally, the paper also referred to Wanghaogu's Tangyenbencao, a text that comprehensibly assembles the authors of Zhangyuans, Yixuqiyan's and Yishuixuepi's knowledge o herbology. Results : The origin of wind herb is 'herbs that uses the unique nature of wind in treatment of disease.' Medication unfolds yang qi, and this signifies the Shengyang function. This means that it starts from the lower energizer yin aspect, which is the beginning point of yang qi, and unfolds to the whole body through upbearing and effusion. Instead of producing yang qi directly similar to pungent, sweet and warm formula, however, it contributes to the achievement of the final purpose of the way of Shengyang through forming a ascending mechanism in the whole body via yin aspect's yang qi upbearing and effusion. Conclusions : Wind herb is within the scope of clinical herbology selected by Lidongyuan, for the purpose of achieving comprehensive clinical purposes, in order to treat internal damage. In this way, wind herb is distinguished from the application of other medicines that are limited in usage depending on Qiwei.

열역학 기반 내부 변수를 이용한 균질화 탄소성 구성방정식 및 입자강화 복합재에서의 소성변형집중 (Homogenized Elastic-plastic Relation based on Thermodynamics and Strain Localization Analyses for Particulate Composite)

  • 윤수진;김기근
    • 소성∙가공
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    • 제33권1호
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    • pp.18-35
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    • 2024
  • In the present work, the evolution rules for the internal variables including continuum damage factors are obtained using the thermodynamic framework, which are in turn facilitated to derive the elastic-plastic constitutive relation for the particulate composites. Using the Mori-Tanaka scheme, the homogenization on state and internal variables such as back-stress and damage factors is carried out to procure the rate independent plasticity relations. Moreover, the degradation of mechanical properties of constituents is depicted by the distinctive damages such that the phase and interfacial damages are treated individually accordingly, whereas the kinematic hardening is depicted by combining the Armstrong-Frederick and Phillips' back-stress evolutions. On the other hand, the present constitutive relation for each phase is expressed in terms of the respective damage-free effective quantities, then, followed by transformation into the damage affected overall nominal relations using the aforementioned homogenization concentration factors. An emphasis is placed on the qualitative analyses for strain localization by observing the perturbation growth instead of the conventional bifurcation analyses. It turns out that the proposed constitutive model offers a wide range of strain localization behavior depending on the evolution of various internal variable descriptions.

Poly(ADP-ribose) protects vascular smooth muscle cells from oxidative DNA damage

  • Zhang, Chao;Luo, Tao;Cui, Shijun;Gu, Yongquan;Bian, Chunjing;Chen, Yibin;Yu, Xiaochun;Wang, Zhonggao
    • BMB Reports
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    • 제48권6호
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    • pp.354-359
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    • 2015
  • Vascular smooth muscle cells (VSMCs) undergo death during atherosclerosis, a widespread cardiovascular disease. Recent studies suggest that oxidative damage occurs in VSMCs and induces atherosclerosis. Here, we analyzed oxidative damage repair in VSMCs and found that VSMCs are hypersensitive to oxidative damage. Further analysis showed that oxidative damage repair in VSMCs is suppressed by a low level of poly (ADP-ribosyl)ation (PARylation), a key post-translational modification in oxidative damage repair. The low level of PARylation is not caused by the lack of PARP-1, the major poly(ADP-ribose) polymerase activated by oxidative damage. Instead, the expression of poly(ADP-ribose) glycohydrolase, PARG, the enzyme hydrolyzing poly(ADP-ribose), is significantly higher in VSMCs than that in the control cells. Using PARG inhibitor to suppress PARG activity facilitates oxidative damage-induced PARylation as well as DNA damage repair. Thus, our study demonstrates a novel molecular mechanism for oxidative damage-induced VSMCs death. This study also identifies the use of PARG inhibitors as a potential treatment for atherosclerosis. [BMB Reports 2015; 48(6): 354-359]

Variation in wind load and flow of a low-rise building during progressive damage scenario

  • Elshaer, Ahmed;Bitsuamlak, Girma;Abdallah, Hadil
    • Wind and Structures
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    • 제28권6호
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    • pp.389-404
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    • 2019
  • In coastal regions, it is common to witness significant damages on low-rise buildings caused by hurricanes and other extreme wind events. These damages start at high pressure zones or weak building components, and then cascade to other building parts. The state-of-the-art in experimental and numerical aerodynamic load evaluation is to assume buildings with intact envelopes where wind acts only on the external walls and correct for internal pressure through separate aerodynamic studies. This approach fails to explain the effect of openings on (i) the external pressure, (ii) internal partition walls; and (iii) the load sharing between internal and external walls. During extreme events, non-structural components (e.g., windows, doors or rooftiles) could fail allowing the wind flow to enter the building, which can subject the internal walls to lateral loads that potentially can exceed their load capacities. Internal walls are typically designed for lower capacities compared to external walls. In the present work, an anticipated damage development scenario is modelled for a four-story building with a stepped gable roof. LES is used to examine the change in the internal and external wind flows for different level of assumed damages (starting from an intact building up to a case with failure in most windows and doors are observed). This study demonstrates that damages in non-structural components can increase the wind risk on the structural elements due to changes in the loading patterns. It also highlights the load sharing mechanisms in low rise buildings.

Anisotropic continuum damage analysis of thin-walled pressure vessels under cyclic thermo-mechanical loading

  • Surmiri, Azam;Nayebi, Ali;Rokhgireh, Hojjatollah;Varvani-Farahani, Ahmad
    • Structural Engineering and Mechanics
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    • 제75권1호
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    • pp.101-108
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    • 2020
  • The present study intends to analyze damage in thin-walled steel cylinders undergoing constant internal pressure and thermal cycles through use of anisotropic continuum damage mechanics (CDM) model coupled with nonlinear kinematic hardening rule of Chaboche. Materials damage in each direction was defined based on plastic strain and its direction. Stress and strain distribution over wall-thickness was described based on the CDM model and the return mapping algorithm was employed based on the consistency condition. Plastic zone expansion across the wall thickness of cylinders was noticeably affected with change in internal pressure and temperature gradients. Expansion of plastic zone over wall-thickness at inner and outer surfaces and their boundaries demarking elastic and plastic regions was attributed to the magnitude of damage induced over thermomechanical cycles on the thin-walled samples tested at various pressure stresses.

국소 전뇌 허혈 모델 백서에서 가감정지환(加減定志丸)과 오수유(吳茱萸)가 기억증진과 신경세포보호에 미치는 효과 (Effect of Gagamjeongji-hwan and Evodiae Fructus on Memory Impairment and Neuronal Damage Induced by Focal Ischemia in the Rat)

  • 김회영;손현수;강지홍;최우정;이진석;양재훈;설재균;이언정
    • 동의생리병리학회지
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    • 제22권6호
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    • pp.1487-1494
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    • 2008
  • This study was conducted to determine the effect of Gagamjeongji-hwan (JJH)(Jiajiandingzhi-wan) and Evoidae Fructus (EF) on learning and memory disturbance and neuronal damage induced by focal ischemia in the rat. Rats were used for testing in the following three. Morris Water Maze, Cholineacetyltransferase (ChAT) immunohistochemistry, acetylcholine esterase (AchE) histochemistry. JJH+ISCH group (ischemia-induced rats pretreated with JJH) and EF+ISCH group (ischemia-induced rats pretreated with EF) significantly reduced the latency of swimming time, compared with those of ISCH group (ischemia-induced rats) in morris water maze acquisition test. JJH+ISCH group attenuated ischemia.induced learning and memory damage in morris water maze retention test. The density of ChAT neurons of the JJH+ISCH and EF+ISCH group in the hippocampal CA1 area was increased, compared to that of SAL+ISCH group (ischemia-induced rats pretreated with SAL). The density of AchE neurons of the JJH+ISCH and EF+ISCH group in the hippocampal CA1 and CA3 area was increased, compared to that of SAL+ISCH group. These results suggest that Gagamjeongji-hwan (JJH) and Evodiae Fructus (EF) may have significant protective effects on ischemia-induced brain damage and memory impairments.

만성 활동성 B형 간염 질환 환자의 요추간판 탈출증 치험례 (Case Report of a Lumbar Disc Herniation (LDH) Patient with Chronic Active Hepatitis B)

  • 정유진;강경래;이민수;최아련;강아현;한동근;송우섭;이형철
    • 대한한방내과학회지
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    • 제37권2호
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    • pp.374-380
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    • 2016
  • Objective: Although the incidence of chronic hepatitis B has decreased around the world due to widespread national preventative control measures, mortality from the same condition can increase if the condition leads to liver cancer or liver cirrhosis. In most cases, herbal medicine does not show any statistically significant effects related to liver damage, but preconceptions do exist that herbal medicine can be toxic and cause such liver damage. To investigate this situation, this study therefore investigated a patient with hepatitis B who had combined traditional Korean medicine therapy and the use of analgesic drugs during a hospitalization period.Method: A patient with hepatitis B was given combined traditional Korean medicine therapy and the use of analgesic drugs during a hospitalization period.Results: Within 26 days, the patient was free from liver damage during the hospitalization period. She was followed up with a liver function test and was discharged after her condition improved; she also reported decreased back pain.

Damage assessment for buried structures against internal blast load

  • Ma, G.W.;Huang, X.;Li, J.C.
    • Structural Engineering and Mechanics
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    • 제32권2호
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    • pp.301-320
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    • 2009
  • Damage assessment for buried structures against an internal blast is conducted by considering the soil-structure interaction. The structural element under analysis is assumed to be rigid-plastic and simply-supported at both ends. Shear failure, bending failure and combined failure modes are included based on five possible transverse velocity profiles. The maximum deflections with respect to shear and bending failure are derived respectively by employing proper failure criteria of the structural element. Pressure-Impulse diagrams to assess damage of the buried structures are subsequently developed. Comparisons have been done to evaluate the influences of the soil-structure interaction and the shear-to-bending strength ratio of the structural element. A case study for a buried reinforced concrete structure has been conducted to show the applicability of the proposed damage assessment method.