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Coupled electrical–thermal finite element analysis (FEA) models are widely adopted to analyze the thermal ablation damage of carbon fiber reinforced polymer (CFRP) caused by lightning, but it is still difficult to analyze the ablation due to its complex space geometry. According to the principle of computerized tomography (CT), tomographic images of FEA models’ temperature fields with different thicknesses were obtained to calculate the mass loss and compare the damage morphology. The four areas including Area 0, Area I, Area II, and Area III; were separated from the temperature fields in terms of different vaporization and pyrolysis temperature ranges of carbon fiber (CF) and resin matrix. Ablation mass losses were calculated by pixel statistics and tomographic intervals, which were consistent with the experimental results. The maximum ablation area of unprotected CFRP was found on the tomography images of 50 μm rather than the surface by comparing tomographic images with different thickness due to the influence of the thermal radiation, but this effect was not found in CFRP protected by copper mesh. Some other phenomena, including continuous evolutions of ablation areas and the influence of the intersection angle on the direction of the ablation extension, were also discovered. 相似文献
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Lightning injuries are one of the top three causes of death from environmental causes. Survivors of lightning injuries may be left with injuries, which may affect either the somatic or autonomic nervous systems. We report on two previously healthy patients who developed severe forms of postural tachycardia syndrome following a lightning injury, and review the literature on the subject. 相似文献
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Kamil Dydek Anna Boczkowska Rafa Kozera Pawe Duraek ukasz Sarniak Magorzata Wilk Waldemar ogin 《Materials》2021,14(11)
The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt.% or 90 wt.% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil. 相似文献
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A patient in perfect health prior to electrical shock developed an ALS-like syndrome after the shock. Onset of the disease occurred in the limb through which the shock entered, and subsequently followed a course well-described in previous case reports. Possible mechanisms of disease are discussed. 相似文献
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Lightning injuries 总被引:1,自引:0,他引:1
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Yehuda Meir Eli Jerby Zahava Barkay Dana Ashkenazi James Brian Mitchell Theyencheri Narayanan Noam Eliaz Jean-Luc LeGarrec Michael Sztucki Oleg Meshcheryakov 《Materials》2013,6(9):4011-4030
This paper presents experimental characterization of plasmoids (fireballs) obtained by directing localized microwave power (<1 kW at 2.45 GHz) onto a silicon-based substrate in a microwave cavity. The plasmoid emerges up from the hotspot created in the solid substrate into the air within the microwave cavity. The experimental diagnostics employed for the fireball characterization in this study include measurements of microwave scattering, optical spectroscopy, small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Various characteristics of these plasmoids as dusty plasma are drawn by a theoretical analysis of the experimental observations. Aggregations of dust particles within the plasmoid are detected at nanometer and micrometer scales by both in-situ SAXS and ex-situ SEM measurements. The resemblance of these plasmoids to the natural ball-lightning (BL) phenomenon is discussed with regard to silicon nano-particle clustering and formation of slowly-oxidized silicon micro-spheres within the BL. Potential applications and practical derivatives of this study (e.g., direct conversion of solids to powders, material identification by breakdown spectroscopy (MIBS), thermite ignition, and combustion) are discussed. 相似文献
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目的 探讨激活大麻素受体2(CB2)对大鼠脓毒症急性肺损伤的保护作用及机制。方法 将48只SD大鼠随机分为对照组、模型组、CB2激动剂组和P38 MAPK抑制剂组(12只/组)。对照组腹腔注射生理盐水,其余3组均腹腔注射脂多糖造模6 h;CB2激动剂组在注射脂多糖前30 min腹腔注射CB2激动剂JWH133(3 mg/kg),P38 MAPK抑制剂组在CB2激动剂组基础上提前30 min腹腔注射P38 MAPK抑制剂SB203580(5 mg/kg)。观察和检测肺组织病理学、含水率、液体清除率、炎症因子的变化情况,肺组织CB2、紧密连接的基因及蛋白表达情况以及P38 MAPK磷酸化情况。结果 与对照组相比,模型组大鼠的肺泡结构破坏严重,液体清除率、肺组织中CB2、occludin和ZO-1蛋白的mRNA及蛋白表达降低,肺组织含水率、P38 MAPK的磷酸化程度、肺灌洗液中TNF-α、IL-1β均增加,差异有统计学意义(P<0.05)。与模型组相比,CB2激动剂组肺泡形态有所恢复,但仍有炎性浸润,肺组织含水率、P38 MAPK磷酸化程度、肺灌洗液中TNF-α、IL-1β降低,液体清除率、肺组织CB2、occludin和ZO-1蛋白的mRNA及蛋白表达增加,差异均有统计学意义(P<0.05)。与CB2激动剂组相比,P38 MAPK抑制剂组肺泡结构有所恢复,肺组织P38 MAPK磷酸化程度、肺灌洗液中TNF-α、IL-1β水平降低,occludin、ZO-1蛋白表达增加,差异均有统计学意义(P<0.05),而CB2的mRNA及蛋白表达无变化(P>0.05)。结论 CB2激活后可通过抑制P38 MAPK信号通路,降低肺组织炎症因子释放,促进紧密连接蛋白表达,对实验性脓毒症大鼠急性肺损伤起到保护作用。 相似文献
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Kondur AK Afonso LC Berenbom LD Lakkireddy DR 《Pacing and clinical electrophysiology : PACE》2008,31(2):256-257
We report an unusual case of a 75-year-old male electrocuted by lightning strike rescued by implantable cardioverter defibrillator (ICD) shock coincidentally. Lightning strikes are an unusual cause of fatal cardiac arrhythmias. Depending on the amount of energy and the current vector affecting the heart, the arrhythmia burden ranges from asystole to ventricular fibrillation. 相似文献