• Title/Summary/Keyword: damage condition

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Methanol Extract of Cassia mimosoides var. nomame and Its Ethyl Acetate Fraction Attenuate Brain Damage by Inhibition of Apoptosis in a Rat Model of Ischemia-Reperfusion

  • Kim, Ki-Hong;Lee, Jong-Won
    • Preventive Nutrition and Food Science
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    • v.15 no.4
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    • pp.255-261
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    • 2010
  • Ischemic stroke, a major cause of death and disability worldwide, is caused by occlusion of cerebral arteries that, coupled with or without reperfusion, results in prolonged ischemia (hypoxia and hypoglycemia) and, ultimately, brain damage. In this study, we examined whether methanol extract of the whole plant of Cassia mimosoides var. nomame Makino that grows naturally in Korea, as well as Japan and China, and some of its fractions obtained by partitioning with organic solvents could protect human hepatocellular carcinoma cells (HepG2) under hypoxic condition by inhibiting apoptosis. We also investigated if these extracts could attenuate brain damage in a rat model of 2 hr of ischemia, generated by middle cerebral artery occlusion, and 22 hr of reperfusion. The whole extract ($100{\mu}g$/mL) maintained the cell number at more than half of that initially plated, even after 24 hr of cell culture under hypoxic condition (3% $O_2$). In the absence of the whole extract, almost all of the cells were dead by this time point. This improvement of cell viability came from a delay of apoptosis, which was confirmed by observing the timing of the formation of a DNA ladder when assessed by gel electrophoresis. Of fractions soluble in hexane, ethyl acetate (EA), butanol and water, EA extracts were selected for the animal experiments, as they improved cell viability at the lowest concentration ($10{\mu}g$/mL). The whole extract (200 mg/kg) and EA extract (10 and 20 mg/kg) significantly reduced infarct size, a measure of brain damage, by 34.7, 33.8 and 45.2.0%, respectively, when assessed by 2,3,5-triphenyl tetrazolium chloride staining. The results suggest that intake of Cassia mimosoides var. nomame Makino might be beneficial for preventing ischemic stroke through inhibition of brain cell apoptosis.

A Comparative Study on Marine Transport Contract and Marine Insurance Contract with Reference to Unseaworthiness

  • Pak, Jee-Moon
    • Journal of Korea Trade
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    • v.25 no.2
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    • pp.152-177
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    • 2021
  • Purpose - This study analyses the excepted requirement and burden of proof of the carrier due to unseaworthiness through comparison between the marine transport contract and marine insurance contract. Design/methodology - This study uses the legal analytical normative approach. The juridical approach involves reviewing and examining theories, concepts, legal doctrines and legislation that are related to the problems. In this study a literature analysis using academic literature and internet data is conducted. Findings - The burden of proof in case of seaworthiness should be based on presumed fault, not proved fault. The burden of proving unseaworthiness/seaworthiness should shift to the carrier, and should be exercised before seeking the protections of the law or carriage contract. In other words, the insurer cannot escape coverage for unfitness of a vessel which arises while the vessel is at sea, which the assured could not have prevented in the exercise of due diligence. The insurer bears the burden of proving unseaworthiness. The warranty of seaworthiness is implied in hull, but not protection and indemnity policies. The 2015 Act repeals ss. 33(3) and 34 of MIA 1906. Otherwise the provisions of the MIA 1906 remain in force, including the definition of a promissory warranty and the recognition of implied warranties. There is less clarity about the position when the source of the loss occurs before the breach of warranty but the actual loss is suffered after the breach. Nonetheless, by s.10(2) of the 2015 Act the insurer appears not to be liable for any loss occurring after the breach of warranty and before there has been a remedy. Originality/value - When unseaworthiness is identified after the sailing of the vessel, mere acceptance of the ship does not mean the party waives any claims for damages or the right to terminate the contract, provided that failure to comply with the contractual obligations is of critical importance. The burden of proof with regards to loss of damage to a cargo caused by unseaworthiness is regulated by the applicable law. For instance, under the common law, if the cargo claimant alleges that the loss or damage has been caused by unseaworthiness, then he has the burden of proof to establish the followings: (i) that the vessel was unseaworthy at the beginning of the voyage; and that, (ii) that the loss or damage has been caused by such unseaworthiness. In other words, if the warranty of seaworthiness at the inception of the voyage is breached, the breach voids the policy if the ship owner had prior knowledge of the unseaworthy condition. By contrast, knowingly permitting the vessel to break ground in an unseaworthy condition denies liability only for loss or damage proximately caused by the unseaworthiness. Such a breach does not, therefore, void the entire policy, but only serves to exonerate the insurer for loss or damage proximately caused by the unseaworthy condition.

A Study on the Strength Properties of Mortar Under Various Types and Contents of Accelerators for Freezing Resistance (내한촉진제의 종류 및 혼입양 변화에 따른 모르터의 강도특성에 관한 연구)

  • Lee, Sang-Soo;Won, Cheol;Park, Sang-Joon;Kim, Dong-Seok
    • Journal of the Korea Institute of Building Construction
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    • v.2 no.2
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    • pp.151-156
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    • 2002
  • When fresh concrete is exposed to low temperature, the concrete may suffer frost damage due to freezing at early ages and strength development may be delayed. One of the solution methods for resolve these problems is to reduce freezing temperature of concrete by the use of chemical admixture called Accelerators for freezing resistance. In this study, we investigate the effect on strength development of cement mortar using accelerators for freezing resistance with the variance curing condition. As the result of this study, the mortar using accelerators for freezing resistance show that continuously strength development in curing condition of -5$^{\circ}C$. And compressive strength under the variance temperature condition was higher than constant temperature condition in same maturity.

The Effect on Strength Development of Cement Mortar using Accelerators for Freezing Resistance with the Curing Condition (양생조건이 내한촉진제를 사용한 시멘트 모르타르의 강도증진에 미치는 영향에 관한 연구)

  • Won, Cheol;Kim, Dong-Seok;Park, Sang-Joon;Lee, Sang-Soo;Kim, Young-Jin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.533-536
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    • 2001
  • When fresh concrete is exposed to low temperature, the concrete may suffer frost damage due to freezing at early ages and strength development may be delayed. One of the solution methods for resolving these problems is to reduce freezing temperature of concrete by the use of chemical admixture called Accelerators for freezing resistance. In this study, we investigate the effect on strength development of cement mortar using accelerators for freezing resistance with the variance curing condition. As the result of this study, the mortar using accelerators for freezing resistance show that continuously strength development in curing condition of -5$^{\circ}C$. And compressive strength under the variance temperature condition was higher than fixed temperature condition in same maturity.

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Development of Deduct Value Curves for the Pavement Condition Index of Asphalt Airfield Pavement (아스팔트 공항포장의 PCI 산출을 위한 공제값 곡선 개발)

  • Lee, Kang-Jin;Seo, Young-Chan;Cho, Nam-Hyun;Park, Dae-Wook
    • International Journal of Highway Engineering
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    • v.15 no.3
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    • pp.37-44
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    • 2013
  • PURPOSES: This study is to develop the deduct value curves for the calculation of pavement condition index of asphalt airfield pavement. METHODS: To develop the deduct value curves of asphalt airfield pavement, panel rating was conducted to decide the pavement condition based on pavement distress type, severity, and density. RESULTS: Results show that standard deviation of deduct values by panel rating is increased at higher severity level and as damage density increases. The deduct value of alligator cracking show the highest. CONCLUSIONS: The deduct value curves based on panel rating could be used without existing problems which were occurred in Shahin's method.

Condition Evaluation of Concrete Bridge Decks using CPR (레이더를 이용한 콘크리트 교량의 바닥판 상태평가)

  • Suh, Jin-Won;Rhee, Ji-Young;Lee, Il-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.4 no.4
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    • pp.101-107
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    • 2000
  • In this study, the Ground Penetrating Radar(GPR) was tested to evaluate the condition of concrete decks. Test results obtained by CPR were compared with values measured from drilled cores and damage mapping by the visual survey. It is shown that GPR can provide highly accurate measurements of layer properties of concrete decks and can map areas of deterioration in bridge decks by dielectric constants. The deck condition can be grouped into categories of "good" or "distressed". The ground penetrating radar data shows promise for producing rapid and accurate condition assessment for bridge decks. And these data can be used to evaluate highway bridge condition and make cost-effective bridge deck rehabilitation by accurately estimating the quantity of deteriorated concrete.

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Condition Monitoring of Hydraulic Piston Motor using Morphological Analysis of Wear Particles (마멸입자 형태해석에 의한 유압피스톤용 모터의 상태감시)

  • 문병주;조연상;박흥식;전태옥
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.6
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    • pp.127-132
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    • 2000
  • Morphological analysis of wear particles is one of useful methods for machine condition monitoring because it is well reflected in machine driving state. This paper was undertaken to apply to the condition monitoring of hydraulic piston motor. The lubricating wear test was performed under different experimental conditions using the wear test device and wear specimens of the pin on disk type was rubbed in paraffinic base oil by three kinds of lubricating materials, varying applied load, sliding distance. The four shape parameters(50% volumetric diameter, aspect, roundness and reflectivity) are used for morphological analysis of wear particles. The results showed that the four shape parameters of wear particles depend on a kind of the lubricating materials. It was capable of calculating presumed wear volume for three kinds of materials on driving time to foresee as damage condition of lubricating materials.

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Pain management in 『Treatise on Cold Damage and Miscellaneous Disease』 according to sufficiency-deficiency of fluid and humor (mainly with greater yang disease part) (진액(津液)의 유무(有無)에 따른 『상한잡병론(傷寒雜病論)』의 통증(痛症) 치법(治法)에 관하여(태양병편을 중심으로))

  • Lee, Myeong-Cheol;Kang, Yeon-Seok
    • The Journal of Korean Medical History
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    • v.27 no.2
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    • pp.135-143
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    • 2014
  • Human body fluid and humor include not only sweat, joint fluid but also every fluids, for example, blood, essence, kidney essence and marrow. Historically, in the oriental medicine, there are a lot of efforts in order to preserve fluid and humor. In "Treatise on Cold Damage and Miscellaneous Disease (傷寒雜病論)", when treating cold damage, preservation of fluid and humor is put first. I tried to find out the relation about fluid and humor and pain treatment in "Treatise on Cold Damage and Miscellaneous Disease". So, I investigated sentences related to pains in "Treatise on Cold Damage and Miscellaneous Disease" "greater yang disease part" and commentaries of several chinese medical doctors. And I divide pain treatments into four categories. (fluid and humor sufficiency-exterior pattern, fluid and humor sufficiency-interior pattern, fluid and humor deficiency-exterior pattern, fluid and humor deficiency-interior pattern) At first, when treating pains of cold damage, there are many considerations about deficiency and sufficiency of fluid and humor through pulse condition and symptoms. Second, in pain-cases of fluid and humor sufficiency, purge methods is chosen. And in pain-cases of fluid and humor deficiency, tonifying methods is chosen. Finally, one of the main objects of "Treatise on Cold Damage and Miscellaneous Disease" is preservation and supply of fluid and humor.

A new approach for quantitative damage assessment of in-situ rock mass by acoustic emission

  • Kim, Jin-Seop;Kim, Geon-Young;Baik, Min-Hoon;Finsterle, Stefan;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • v.18 no.1
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    • pp.11-20
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    • 2019
  • The purpose of this study was to propose a new approach for quantifying in situ rock mass damage, which would include a degree-of-damage and the degraded strength of a rock mass, along with its prediction based on real-time Acoustic Emission (AE) observations. The basic approach for quantifying in-situ rock mass damage is to derive the normalized value of measured AE energy with the maximum AE energy, called the degree-of-damage in this study. With regard to estimation of the AE energy, an AE crack source location algorithm of the Wigner-Ville Distribution combined with Biot's wave dispersion model, was applied for more reliable AE crack source localization in a rock mass. In situ AE wave attenuation was also taken into account for AE energy correction in accordance with the propagation distance of an AE wave. To infer the maximum AE energy, fractal theory was used for scale-independent AE energy estimation. In addition, the Weibull model was also applied to determine statistically the AE crack size under a jointed rock mass. Subsequently, the proposed methodology was calibrated using an in situ test carried out in the Underground Research Tunnel at the Korea Atomic Energy Research Institute. This was done under a condition of controlled incremental cyclic loading, which had been performed as part of a preceding study. It was found that the inferred degree-of-damage agreed quite well with the results from the in situ test. The methodology proposed in this study can be regarded as a reasonable approach for quantifying rock mass damage.

Electrochemical Characteristics and Damage Behavior in Cathode Operating Conditions of 316L Stainless Steel with Test Time and Applied Potential in Metallic Bipolar Plates for PEMFC (고분자 전해질 연료전지 양극 작동 환경에서 실험 시간 및 작동 전압 변수에 따른 316L 스테인리스강의 전기화학적 특성과 손상 거동)

  • Shin, Dong-Ho;Kim, Seong-Jong
    • Corrosion Science and Technology
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    • v.20 no.6
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    • pp.451-465
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    • 2021
  • In this investigation, electrochemical characteristics and damage behavior of 316L stainless steel polymer electrolyte membrane fuel cell(PEMFC) were analyzed by potentiodynamic and potentiostatic tests in cathode operating condition of PEMFC. As the result of potentiodynamic polarization test, range of passive region was larger than range of active region. In the result of potentiostatic test, damage depth and width, pit volume, and surface roughness were increased 1.57, 1.27, 2.48, and 1.34 times, respectively, at 1.2 V compared to 0.6 V at 24 hours. Also, as a result of linear regression analysis of damage depth and width graph, trend lines of damage depth and width according to applied potentials were 16.6 and 14.3 times larger, respectively. This demonstrated that applied potential had a greater effect on pitting damage depth of 316L stainless steel. The damage tendency values were 0.329 at 6 hours and 0.633 at 24 hours with applied potentials, representing rapid growth in depth direction according to the test times and applied potentials. Scanning electron microscopy images revealed that surface of specimen exhibited clear pitting damage with test times and applied potentials, which was thought to be because a stable oxide film was formed by Cr and Mo.