835 resultados para TO-CUT MATERIALS


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The focused ion beam microscope (FIB) has been used to fabricate thin parallel-sided ferroelectric capacitors from single crystals of BaTiO3 and SrTiO3. A series of nano-sized capacitors ranging in thickness from similar to660 nm to similar to300 nm were made. Cross-sectional high resolution transmission electron microscopy (HRTEM) revealed that during capacitor fabrication, the FIB rendered around 20 nm of dielectric at the electrode-dielectric interface amorphous, associated with local gallium impregnation. Such a region would act electrically in series with the single crystal and would presumably have a considerable negative influence on the dielectric properties. However, thermal annealing prior to gold electrodes deposition was found to fully recover the single crystal capacitors and homogenise the gallium profile. The dielectric testing of the STO ultra-thin single crystal capacitors was performed yielding a room temperature dielectric constant of similar to300, as is the case in bulk. Therefore, there was no evidence of a collapse in dielectric constant associated with thin film dimensions.

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Electrochemical capacitors, also known as supercapacitors, are becoming increasingly important components in energy storage, although their widespread use has not been attained due to a high cost/ performance ratio. Fundamental research is contributing to lowered costs through the engineering of new materials. Currently the most viable materials used in electrochemical capacitors are biomassderived and polymer-derived activated carbons, although other carbon materials are useful research tools. Metal oxides could result in a step change for electrochemical capacitor technology and is an exciting area of research. The selection of an appropriate electrolyte and electrode structure is fundamental in determining device performance. Although there are still many uncertainties in understanding the underlying mechanisms involved in electrochemical capacitors, genuine progress continues to be made. It is argued that a large, collaborative international research programme is necessary to fully develop the potential of electrochemical capacitors.

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With the increase in construction in dense urban environments, the delays associated with managing the material supply chain to site is called into question. Purpose: The aim of this investigation is to gain the perspective of construction contractors operating in a dense urban environment and the resulting strategies adopted to reduce delays in the delivery of materials to site. Methodology: This is achieved through incorporating a comprehensive literature review on the subject in conjunction with industry interviews with construction professionals in the identification of various management issues and corresponding strategies in the reduction of delays in the delivery of materials to site. Findings: The key issue which emerges is the lack of space for unloading bays while the corresponding key strategy is to schedule deliveries outside peak congestion times. Practical Implication: With confined site construction evident throughout the industry and the noted importance of an effective supply chain, the findings here in further assist on-site management in the daily task of ensuring the effective delivery and off-loading of materials in a complex and hazardous environment. Originality/Value: This research aids on-site management of confined site environments in the coordination of the material supply chain to site.

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'If we do not cut social spending, we will end up like Greece'. Establishment politicians and media figures use this new ideological mantra throughout the Western world to frighten people into consenting to further neo-liberal restructuring along with cuts in social spending. This phrase and other ideologically laden assertions hide the real causes of the Greek public debt crisis. This commentary challenges the dominant discourse by contextualizing the Greek case within the larger global neo-liberal restructuring processes and then, drawing upon Gramsci's concept of the organic intellectual, proposes ways that the members of the Professional Association of Social Workers (PASW) can engage in a war of ideas and action, as organic intellectuals, to delegitimize the dominant discourse, which seeks consent for social spending cuts and further neo-liberal restructuring of society. © The Author(s) 2013.