4,308 research outputs found

    A random wave model for the Aharonov-Bohm effect

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    We study an ensemble of random waves subject to the Aharonov-Bohm effect. The introduction of a point with a magnetic flux of arbitrary strength into a random wave ensemble gives a family of wavefunctions whose distribution of vortices (complex zeros) are responsible for the topological phase associated with the Aharonov-Bohm effect. Analytical expressions are found for the vortex number and topological charge densities as functions of distance from the flux point. Comparison is made with the distribution of vortices in the isotropic random wave model. The results indicate that as the flux approaches half-integer values, a vortex with the same sign as the fractional part of the flux is attracted to the flux point, merging with it at half-integer flux. Other features of the Aharonov-Bohm vortex distribution are also explored.Comment: 16 pages, 5 figure

    Monitoring global vegetation

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    An attempt is made to identify the need for, and the current capability of, a technology which could aid in monitoring the Earth's vegetation resource on a global scale. Vegetation is one of our most critical natural resources, and accurate timely information on its current status and temporal dynamics is essential to understand many basic and applied environmental interrelationships which exist on the small but complex planet Earth

    Explosion at Cardowan Colliery Lanarkshire

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    ERAF: A6.CMND.1260MINISTRY OF POWER EXPLOSION AT CARDOWAN COLLIERY LANARKSHIRE REPORT On the causes of, and circumstances attending, the explosion which occurred at Cardowan Colliery, Lanarkshire, on 25th July, 1960 BY H. R. HOUSTON, C.B.E . H.M. Deputy Chief Inspector of Mines and Quarries Presented to Parliament by the Minister of Power by Command of Her Majesty January 196

    The Dark Tetrad empowered: the Dark Tetrad and power motivations within the normal personality space

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    Within personality psychology there has been a surge in research regarding the Dark Tetrad of personality (Buckels, Jones, & Paulhus, 2014). This research has focused on the way these constructs are related to diverse variables of interest. The present research builds on the prior studies by expanding the exploration into the common features that comprise the four constructs. The hypotheses were that each construct would correlate with facets of Honesty/Humility, Emotionality, Agreeableness, and Conscientiousness, along with four aspects of power motivations, and that narcissism would be connected to Extraversion. Also, it was hypothesized that facets of these domains, as well as power motivations. would be predictive of levels of the dark constructs. These hypotheses were tested against a sample of 300 subjects from Western Carolina University. Results showed predictive significance on the hypothesized models explaining variance within each of the four constructs of Sadism (R2 = 0.27), Machiavellianism (R2 = 0.31), Psychopathy (R2 = 0.40), and Narcissism (R2 = 0.66)

    Inspection of the Lower Half of Wing Lap Joints with EMATs

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    Detection of fatigue cracks at the fastener holes in the lower portion of the C5A wing lap joint is complicated by lack of a direct line of access, and by the presence of fasteners and sealant material. Furthermore, any successful detection procedure must take into account the wide variation in the geometrical features of the joint. In this work, periodic permanent magnet EMATs (electromagnetic-acoustic transducers) have been employed to excite the n=o horizontally polarized shear mode of the skin at 200 kHz and 250 kHz. These modes are partially transmitted into the overlap region joined by the fastener. Spectral analysis of suitably time gated and apodized portions of the reflected waveform have allowed simulated cracks growing out of fastener holes to be detected, and preliminary sizing algorithms have been developed

    Endothelium-derived relaxing factor and coronary vasospasm.

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    The endothelium releases the powerful vasodilator and antiaggregatory substance, EDRF, both under basal conditions and upon stimulation by a wide variety of agents. Endothelial injury or dysfunction may play an important role in the spasmogenicity of the coronary artery, although other possible alterations related to atherosclerosis should also be considered. Among the possible stimuli, aggregating platelets are important as a source of vasoconstrictor substances. The endothelium may also produce the vasoactive substances EDHF and EDCF(s). Their pathophysiologic significance remains to be determined.link_to_subscribed_fulltex

    Hybrid in vitro diffusion cell for simultaneous evaluation of hair and skin decontamination: temporal distribution of chemical contaminants

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    Most casualty or personnel decontamination studies have focused on removing contaminants from the skin. However, scalp hair and underlying skin are the most likely areas of contamination following airborne exposure to chemicals. The aim of this study was to investigate the interactions of contaminants with scalp hair and underlying skin using a hybrid in vitro diffusion cell model. The in vitro hybrid test system comprised “curtains” of human hair mounted onto sections of excised porcine skin within a modified diffusion cell. The results demonstrated that hair substantially reduced underlying scalp skin contamination and that hair may provide a limited decontamination effect by removing contaminants from the skin surface. This hybrid test system may have application in the development of improved chemical incident response processes through the evaluation of various hair and skin decontamination strategies.Peer reviewedFinal Published versio
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