60 research outputs found

    Tribostimulated Emission of Electrons and Neutral Particles from Anodized Aluminum

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    The physical and chefmical properties of anodic oxide layers on metals such as Al play important roles in a number of applications such as adhesive bonding and corrosion resistance. An overall test of an oxide layer sensitive to a number of oxide properties is difficult to find. We have been studying the tribostimulated emission of charged particles, neutral particles, and photons during tensile deformafion of anodically oxidized Al alloys. The characteristic emission curve (emission rate vs. strain of the Al substrate during constant strain rate) is found to depend strongly on the anodization parameters. A comparison of neutral particle emission with electron emission will be presented. Correlations between acoustic emission from oxide cracking and electron emission will also be discussed

    Recent Decisions

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    Comments on recent decisions by William A. Alder, William B. Ball, John F. Bodle, Wm. J. Braunlich, Jr., James A. Cassidy, John J. Cauley, F. J. Coufal, Louis F. Di Giovanni, George B. Kashmer, Robert D. Londergan, James W. Oberfell, Robert S. Olivier, William V. Phelan, John G. Smith, E. A. Steffen, Jr., Edward L. Twohey, and Robert R. Uhl

    Status Update and Interim Results from the Asymptomatic Carotid Surgery Trial-2 (ACST-2)

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    Objectives: ACST-2 is currently the largest trial ever conducted to compare carotid artery stenting (CAS) with carotid endarterectomy (CEA) in patients with severe asymptomatic carotid stenosis requiring revascularization. Methods: Patients are entered into ACST-2 when revascularization is felt to be clearly indicated, when CEA and CAS are both possible, but where there is substantial uncertainty as to which is most appropriate. Trial surgeons and interventionalists are expected to use their usual techniques and CE-approved devices. We report baseline characteristics and blinded combined interim results for 30-day mortality and major morbidity for 986 patients in the ongoing trial up to September 2012. Results: A total of 986 patients (687 men, 299 women), mean age 68.7 years (SD ± 8.1) were randomized equally to CEA or CAS. Most (96%) had ipsilateral stenosis of 70-99% (median 80%) with contralateral stenoses of 50-99% in 30% and contralateral occlusion in 8%. Patients were on appropriate medical treatment. For 691 patients undergoing intervention with at least 1-month follow-up and Rankin scoring at 6 months for any stroke, the overall serious cardiovascular event rate of periprocedural (within 30 days) disabling stroke, fatal myocardial infarction, and death at 30 days was 1.0%. Conclusions: Early ACST-2 results suggest contemporary carotid intervention for asymptomatic stenosis has a low risk of serious morbidity and mortality, on par with other recent trials. The trial continues to recruit, to monitor periprocedural events and all types of stroke, aiming to randomize up to 5,000 patients to determine any differential outcomes between interventions. Clinical trial: ISRCTN21144362. © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved

    Closed-loop control of product properties in metal forming

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    Metal forming processes operate in conditions of uncertainty due to parameter variation and imperfect understanding. This uncertainty leads to a degradation of product properties from customer specifications, which can be reduced by the use of closed-loop control. A framework of analysis is presented for understanding closed-loop control in metal forming, allowing an assessment of current and future developments in actuators, sensors and models. This leads to a survey of current and emerging applications across a broad spectrum of metal forming processes, and a discussion of likely developments.Engineering and Physical Sciences Research Council (Grant ID: EP/K018108/1)This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.cirp.2016.06.00

    Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy

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    Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86–1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91–1·32; p=0·21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable. Funding: UK Medical Research Council and Health Technology Assessment Programme

    Tribostimulated Emission of Electrons and Neutral Particles from Anodized Aluminum

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    The physical and chefmical properties of anodic oxide layers on metals such as Al play important roles in a number of applications such as adhesive bonding and corrosion resistance. An overall test of an oxide layer sensitive to a number of oxide properties is difficult to find. We have been studying the tribostimulated emission of charged particles, neutral particles, and photons during tensile deformafion of anodically oxidized Al alloys. The characteristic emission curve (emission rate vs. strain of the Al substrate during constant strain rate) is found to depend strongly on the anodization parameters. A comparison of neutral particle emission with electron emission will be presented. Correlations between acoustic emission from oxide cracking and electron emission will also be discussed.</p

    Tribostimulated Emission of Electrons and Neutral Particles from Anodized Aluminum

    No full text
    The physical and chefmical properties of anodic oxide layers on metals such as Al play important roles in a number of applications such as adhesive bonding and corrosion resistance. An overall test of an oxide layer sensitive to a number of oxide properties is difficult to find. We have been studying the tribostimulated emission of charged particles, neutral particles, and photons during tensile deformafion of anodically oxidized Al alloys. The characteristic emission curve (emission rate vs. strain of the Al substrate during constant strain rate) is found to depend strongly on the anodization parameters. A comparison of neutral particle emission with electron emission will be presented. Correlations between acoustic emission from oxide cracking and electron emission will also be discussed.</p
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