• Title/Summary/Keyword: failure line

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A Study on the Concept and Clinical Application of "冬不藏精, 春必病溫" ("동부장정(冬不藏精), 춘필병온(春必病溫)"의 개념 및 임상활용에 대한 고찰)

  • Eun, Seok-min
    • Journal of Korean Medical classics
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    • v.32 no.4
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    • pp.17-33
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    • 2019
  • Objectives : The verse, "冬不藏精, 春必病溫", which had much influence, has been falsely referenced as contents of "Neijing". This study aims to examine this process, while looking at its theoretical meaning within clinical practice. Methods : The origins of the concept "冬不藏精, 春必病溫" are explained through annotations of "Neijing" and Li Dong Yuan(李東垣)'s interpretation of Shanghan(傷寒), while its clinical meaning is examined through theories of doctors's who applied the concept in their practices. Results : The beginning of "冬不藏精, 春必病溫" could be traced back to Li's annotation of the verse "冬傷于寒, 春必病溫" from the "Neijing", where he based his understanding on the concept "少陰不藏." Since then, the discourse on "冬傷于寒, 春必病溫" has been replaced by "冬不藏精, 春必病溫" as a new concept to explain the pathology of Wenbing(溫病). These discussions followed the line of thought that by failure to store Jing(精) during the winter, Cold pathogen would infiltrate, hiding itself in Shaoyin(少陰). Various arguments on how the Cold pathogen would develop into Wenbing and its treatment followed. Conclusions : "冬不藏精, 春必病溫" can be understood as the result of a new interpretation of "冬傷于寒, 春必病溫" through the perspective of Cold pathogen infiltration based on "少陰不藏".

Investigation of bond-slip modeling methods used in FE analysis of RC members

  • Demir, Serhat;Husem, Metin
    • Structural Engineering and Mechanics
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    • v.56 no.2
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    • pp.275-291
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    • 2015
  • Adherence between reinforcement and the surrounding concrete is usually ignored in finite element analysis (FEA) of reinforced concrete (RC) members. However, load transition between the reinforcement and surrounding concrete effects RC members' behavior a great deal. In this study, the effects of bond-slip on the FEA of RC members are examined. In the analyses, three types of bond-slip modeling methods (perfect bond, contact elements and spring elements) and three types of reinforcement modeling methods (smeared, one dimensional line and three dimensional solid elements) were used. Bond-slip behavior between the reinforcement and surrounding concrete was simulated with cohesive zone materials (CZM) for the first time. The bond-slip relationship was identified experimentally using a beam bending test as suggested by RILEM. The results obtained from FEA were compared with the results of four RC beams that were tested experimentally. Results showed that, in FE analyses, because of the perfect bond occurrence between the reinforcement and surrounding concrete, unrealistic strains occurred in the longitudinal reinforcement. This situation greatly affected the load deflection relationship because the longitudinal reinforcements dominated the failure mode. In addition to the spring elements, the combination of a bonded contact option with CZM also gave closer results to the experimental models. However, modeling of the bond-slip relationship with a contact element was quite difficult and time consuming. Therefore bond-slip modeling is more suitable with spring elements.

Development of gamma ray scanning coupled with computed tomographic technique to inspect a broken pipe structure inside laboratory scale vessel

  • Saengchantr, Dhanaj;Srisatit, Somyot;Chankow, Nares
    • Nuclear Engineering and Technology
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    • v.51 no.3
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    • pp.800-806
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    • 2019
  • This paper presents a laboratory experiment on data acquisition technique that applied to the gamma radiation scanning coupled with computed tomography (CT) technique for inspection of broken nozzle inside the vertical vessel. The acquisition technique was developed to inspect a large diameter vessel when suspicious problem location is not easily accessed. This technique allows the installation of gamma radiation source (Cesium 137, Cs-137), and detectors (Sodium Iodine. NaI(Tl)) from the accessible location to the required location and performs the scanning by designed pattern. To demonstrate the designed technique, top opened tank which installed with six cut steel pipes diameter of 76.2 mm (3") at a certain position was selected. They were assumed to be a gas riser pipes inside the vessel. Three studied cases were performed, (a) projection of well installed six pipes, (b) projection of one out of six broken pipe and (c) one of nozzle was assumed to be failure and fell down until one out of six pipes was broken and obstructed by nozzle. Results clearly indicated the capability of developed technique to distinguish between normal situation case and abnormal situation cases.

Experimental approach to estimate strength for compacted geomaterials at low confining pressure

  • Kim, Byeong-Su;Kato, Shoji;Park, Seong-Wan
    • Geomechanics and Engineering
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    • v.18 no.5
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    • pp.459-469
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    • 2019
  • It is important to estimate the shear strength of shallow compacted soils as a construction material. A series of constant water content triaxial compression (CWCC) tests under low confining state in this study were performed on compacted geomaterials. For establishing a relationship of the shear strengths between saturated and unsaturated states on compacted geomaterials, the suction stresses were derived by two methods: the conventional suction-measured method and the Suction stress-SWRC Method (SSM). Considering the suction stress as an equivalent confining stress component in the (${\sigma}_{net}$, ${\tau}$) plane, it was found that the peak deviator stress states agree well with the failure line of the saturated state from the triaxial compression test when the SSM is applied to obtain the suction stress. On the other hand, the cavitation phenomenon on the measurement of suction affected the results of the conventional suction-measured method. These results mean that the SSM is distinctly favorable for obtaining the suction value in the CWCC test because the SSM is not restricted by the cavitation phenomenon. It is expected that the application of the SSM would reduce the time required, and the projected cost with the additional equipment such as a pore water measuring device in the CWCC test.

New Helicobacter pylori Eradication Therapies (새로운 헬리코박터 제균 요법)

  • Park, Jae Yong;Kim, Jae Gyu
    • The Korean Journal of Gastroenterology
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    • v.72 no.5
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    • pp.237-244
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    • 2018
  • While the prevalence of Helicobacter pylori (H. pylori) infection is decreasing in Korea, the incidence of gastric cancer remains high, emphasizing the importance of H. pylori eradication. A new treatment strategy is needed as the eradication rate with standard triple therapy, which is currently the standard first-line regimen for H. pylori infection, has decreased below the optimum level. The major cause of eradication failure is increased antibiotic resistance. Sequential, concurrent, and hybrid therapies that include clarithromycin produce higher eradication rates than conventional standard triple therapy. However, the effectiveness of these treatments is limited in regions where the resistance rate to various antibiotics is high. Bismuth quadruple therapy is another alternative therapy, but again the eradication rate is not sufficiently high. Tailored therapy based on individual characteristics, including antibiotic susceptibility, may be ideal, but there are several limitations for clinical application and further research is needed. New potassium-competitive acid blocker-based therapies could emerge as effective alternatives in the near future. A consensus is needed to establish a strategy for applying new eradication therapies in Korea.

Study on seismic performance of steel frame with archaized-style under pseudo-dynamic loading

  • Liu, Zuqiang;Zhou, Chaofeng;Xue, Jianyang
    • Earthquakes and Structures
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    • v.17 no.1
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    • pp.39-48
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    • 2019
  • This paper presents an experimental study on a 1/2 scale steel frame with archaized-style under the pseudo-dynamic loading. Four seismic waves, including El Centro wave, Taft wave, Lanzhou wave and Wenchuan wave, were input during the test. The hysteresis characteristic, energy dissipation acceleration response, displacement response, strength, stiffness and strain were analyzed. Based on the experiment, the elastoplastic dynamic time-history analysis was carried out with the software ABAQUS. The stress distribution and failure mode were obtained. The results indicate that the steel frame with archaized-style was in elastic stage when the peak acceleration of input wave was no more than 400 gal. Under Wenchuan wave with peak acceleration of 620 gal, the steel frame enters into the elastoplastic stage, the maximum inter-story drift was 1/203 and the bearing capacity still tended to increase. During the loading process, Dou-Gong yielded first and played the role of the first seismic fortification line, and then beam ends and column bottom ends yielded in turn. The steel frame with archaized-style has good seismic performance and meets the seismic design requirement of Chinese code.

Analysis of the Phillips Curve: An Assessment of Turkey

  • NAR, Mehmet
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.65-75
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    • 2021
  • This study analyzes the validity of the Phillips curve with regards to Turkey. The existence and direction of the causality relationship (reason-outcome relationship) between unemployment and inflation is investigated using inflation and unemployment data for the period 1980-2019. Unit root tests were utilized to evaluate the stationarity of the series. In line with the Zivot-Andrews unit root test, which was developed in response to the criticism of the failure of studies that presented macro-variables like inflation to consider traditional unit root tests, in this research, the Engle-Granger cointegration test was implemented to check whether the series could perform a joint action, and, finally, the Granger causality relationship was explored. According to the results of the analysis, over the relevant period there was a single directional causality relationship from inflation toward unemployment in Turkey. The importance of this relationship at the 10% significance level indicates the existence of many different factors that affect inflation and unemployment. Given the existence of a cointegration and causality relationship between inflation and unemployment, it can be said that, in Turkey, the Phillips curve is valid for the period 1980-2019 and that an increase of 1% in inflation will reduce the unemployment rate by 0.028%.

Experience and Analysis of Pole Interaction for Jeju HVDC No. 2: Practical Solution for Non-Interruptible Power Transfer (제주 HVDC No. 2의 극간 상호작용 경험과 분석: 무정전 전력 송전을 위한 실용적 해결방안)

  • Kim, Hee-Jin;Kim, Chan-Ki;Park, Chang-Hwan
    • The Transactions of the Korean Institute of Power Electronics
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    • v.25 no.6
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    • pp.459-468
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    • 2020
  • The pole interaction of the line-commutated converter high-voltage direct current (HVDC) is analyzed, and a practical solution that uses a surge arrester is proposed. Jeju HVDC No. 2 is a double-monopole HVDC link that has a rated power capacity of 2 × 200 MW and was commissioned in 2012. During normal operation, Jeju HVDC No. 2 is operated in the bipolar mode to minimize the loss caused by the dedicated metallic return. However, when one pole of the inverter valve is bypassed, a commutation failure can occur in the other pole. This phenomenon is called pole interaction in this work. This pole interaction interrupts the HVDC power transfer for almost 2 s and may affect the stability of the power system. This research proposes the installation of a surge arrester at the inverter neutral, which can be an effective and practical solution for pole interaction. The HVDC system is analyzed, and the residual voltage of the surge arrester is determined. Detailed simulation using PSCAD/EMTDC demonstrates that the proposed method eliminates the pole interaction of the bipolar-operated HVDC.

Norflurazon causes developmental defects including cardiovascular abnormalities in early-stage zebrafish (Danio rerio)

  • An, Garam;Park, Hahyun;Hong, Taeyeon;Song, Gwonhwa;Lim, Whasun
    • Journal of Animal Reproduction and Biotechnology
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    • v.37 no.3
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    • pp.176-182
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    • 2022
  • Norflurazon is widely used on agricultural lands and has a high potential to pollute water sources. However, its effects on fish have not been fully elucidated. The purpose of our study was to determine whether norflurazon adversely affects the developmental stage of zebrafish, which are frequently used as a model system to evaluate the environmental impact of pollutants. Norflurazon interfered with the hatching of zebrafish embryos and induced several sublethal deformities including body length reduction, increased yolk sac volume, and enlargement of the pericardial region. We further examined the cardiotoxicity of norflurazon in the flk1:eGFP transgenic zebrafish line. The vascular network, mainly in the brain region, was significantly disrupted in norflurazon-exposed zebrafish. In addition, due to the failure of cardiac looping, norflurazon-exposed zebrafish had an abnormal cardiac structure. These developmental abnormalities were related to the apoptotic process triggered by norflurazon. Overall, the present study demonstrated the non-target toxicity of norflurazon by analyzing the hazardous effects of norflurazon on developing zebrafish.

Evaluation of Dowel Bearing Strength of Structural Composite Lumber(SCL) on the Effect of Moisture Content

  • Oh, Sei Chang
    • Journal of the Korean Wood Science and Technology
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    • v.31 no.3
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    • pp.61-69
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    • 2003
  • This study investigated the effect of moisture content and loading direction on dowel bearing strength of two types of SCL. Dowel bearing tests of LVL and PSL were conducted with two different MC level, 7.5% and 19%, and two different oriention, L-direction(loading parallel to grain) and X-direction(loading perpendicular to grain). Most of specimens showed typical load-deformation curves and intersected 5% offset line. Failure modes were classified into two categories; spliting(for L-direction specimens) and peeling(for X-direction specimens). Dowel bearing strength generally decreased with increasing MC. The decreasing rate was more significant in X-directon. ESG also decreased with increasing MC, and the ratio of ESG of 7.5% versus 19% was about 1.47. Dowel bearing strength of LVL and PSL in L-direction was higher than that of X-direction. This results indicated that MC and loading orientation had a significant effect on dowel bearing strength of SCL. The average dowel bearing strength of LVL were higher than that of PSL in each loading direction. Two types of probability distribution model were chosen to quantify strength distribution, normal and 2-parameter weibull distribution. The two models showed good agreement with the data, especially in lower tail of the cumulative distribution. Normal and 2-parameter weibull distribution seemed to proper model of the dowel bearing strength for each MC levels.