Thermal Ablation Damage Analysis of CFRP Suffering from Lightning Based on Principles of Tomography

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.     

Progressive motor neuron disease associated with electrical injury

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.     

Effect of SWCNT-Tuball Paper on the Lightning Strike Protection of CFRPs and Their Selected Mechanical Properties

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.     

New onset postural tachycardia syndrome following lightning injury

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.     

二甲双胍对肺腺癌细胞Nrf2基因表达的调控作用研究

目的 探讨Nrf2基因在对顺铂耐药的肺腺癌细胞中的表达及二甲双胍对其调控作用的研究.方法 应用细胞增殖实验(CCK-8)和流式细胞仪,检测二甲双胍对肺腺癌A549和A549/DDP细胞增殖抑制率、凋亡率,Real-timePCR检测相关耐药基因表达,Western Blot法检测相关蛋白水平表达.结果 Nrf2、GST...     

开县雷击事件对中小学生心理的影响研究

目的 研究重庆开县雷击事件对学生心理健康的影响及相应心理干预的效果.方法 采用心理健康诊断测验(MHT)对雷击组和对照组各49人进行心理健康水平测定.对雷击组学生进行心理干预.结果 雷击组的心理健康水平显著低于对照组,雷击事件对5年级学生心理健康的影响显著大于7年级学生.结论 对雷击组进行心理干预,干预效果显著,但5年级学生的干预效果显著好于7年级学生.     

Observations of Ball-Lightning-Like Plasmoids Ejected from Silicon by Localized Microwaves

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.     

Neurological and neuropsychological consequences of electrical and lightning shock:review and theories of causation

Injuries from lightning and electrical injuries involve multiple systems of the body, however neurological symptoms are very widely reported. A disabling neuropsychological syndrome is also noted.This paper presents a comprehensive review of neurological and neuropsychological symptoms. Partial theories of causation for these injuries have been advanced, however, there is no convincing explanation for both delay in onset of symptoms and also the genesis of the neuropsychological syndrome. A theory of causation is proposed which satisfies both these constraints.This theory suggests circulating hormones such as cortisol, together with nitric oxide and oxidant free radicals from glutamatergic hyper-stimulation, act on tissues remote from the injury path including the hippocampus.This theory opens a research path to explore treat-ment options.     

Lightning induced inappropriate ICD shock: an unusual case of electromagnetic interference

An unusual case of electromagnetic interference is presented. As a result of a lightning shock to a Shower House, our patient received two shocks. An elucidation of the different mechanisms for the two shocks is presented.     

National athletic trainers' association position statement: preventing sudden death in sports

Objective:

To present recommendations for the prevention and screening, recognition, and treatment of the most common conditions resulting in sudden death in organized sports.

Background:

Cardiac conditions, head injuries, neck injuries, exertional heat stroke, exertional sickling, asthma, and other factors (eg, lightning, diabetes) are the most common causes of death in athletes.

Recommendations:

These guidelines are intended to provide relevant information on preventing sudden death in sports and to give specific recommendations for certified athletic trainers and others participating in athletic health care.