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This paper describes both the mechanical and corrosion behaviour of similar made from AA2024 and AA6056, all in form of rolled sheet Friction Stir Welding (FSW) lap joints. The effects of heating using three different weld speeds, on both alloys employed in this work, were also investigated. Static mechanical tests were carried out providing infor-mation about static strengths and failure modes. Optical observation was used in investigating imicroscopically weld and welding defects. The corrosion behaviour of such joints was investigated by electrochemical dc techniques (open circuit potential -O.C.P. - monitoring and anodic polarization) using a cap-illary electrochemical cell, with a resolution of 0.5 mm. In order to confirm results obtained by local measure-ments, global gel visualization tests were also performed on the same specimens. The best mechanical and electrochemical performance was observed when the weld speed is low. In AA6056 fail-ure occurs in weld along the mixing area, while in the case of welding AA2024 it occurs mainly in the lower plate, most critical zone is the HAZ. [ABSTRACT FROM AUTHOR]

The interaction between matter and microwaves assumes critical significance due to the ubiquity of wireless communication technology. The selective shielding of microwaves represents the only way to achieve the control on crucial technological sectors. The implementation of microwave shielding ensures the proper functioning of electronic devices. By preventing electromagnetic pollution, shielding safeguards the integrity and optimal performances of devices, contributing to the reliability and efficiency of technological systems in various sectors and allowing the further step forwards in a safe and secure society. Nevertheless, the microwave shielding research is vast and can be quite hard to approach due to the large number and variety of studies regarding both theory and experiments. In this review, we focused our attention on the comprehensive discussion of the current state of the art of materials used for the production of electromagnetic interference shielding composites, with the aim of providing a solid reference point to explore this research field.

Background: Physicians in intensive care units have withdrawn life support in incapacitated patients who lack surrogate decision makers and advance directives, yet little is known about how often this occurs or under what circumstances., Objective: To determine the proportion of deaths in intensive care units that occur in patients who lack decision-making capacity and a surrogate and the process that physicians use to make these decisions., Design: Multicenter, prospective cohort study., Setting: Intensive care units of 7 medical centers in 2004 to 2005., Patients: 3011 consecutive critically ill adults., Measurements: Attending physicians completed a questionnaire about the decision-making process for each incapacitated patient without a surrogate or advance directive for whom they considered limiting life support., Results: Overall, 5.5% (25 of 451 patients) of deaths in intensive care units occurred in incapacitated patients who lacked a surrogate decision maker and an advance directive. This percentage ranged from 0% to 27% across the 7 centers. Physicians considered limiting life support in 37 such patients or would have considered it if a surrogate had been available. In 6 patients, there was prospective hospital review of the decision, and in 1 patient, there was court review. In the remaining 30 patients, the decision was made by the intensive care unit team alone or by the intensive care unit team plus another attending physician. The authors found wide variability in hospital policies, professional society guidelines, and state laws regarding who should make life-support decisions for this patient population. Thirty-six of 37 life-support decisions were made in a manner inconsistent with American College of Physicians guidelines for judicial review., Limitations: The results are based on physicians' self-reported practices and may not match actual practices. The number of incapacitated patients without surrogates in the study is small., Conclusions: Incapacitated patients without surrogates accounted for approximately 1 in 20 deaths in intensive care units. Most life-support decisions were made by physicians without institutional or judicial review.