A Rough and Ready Galvanic Battery

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Problems of perceptibility affecting formal design in Nontonal music

The thesis argues that the absence of traditional referential elements,-such as tonality and metre, affects the exactitude with which the listener perceives certain aspects of nontonal music. It claims that the listener might impose his own interpretation on a work in which the musical patterns are too complex to be perceived exactly and that, in extreme cases, the patterns which the listener reads into the music may be completely subjective. The thesis examines the extent to which Webern and some post-Webernian composers determine the listener's response to their music and shows that certain aspects of Webern's music are simple enough to be easily grasped and to be perceived exactly and that these aspects control the way in which the listener understands Webern's music. It suggests that the nature of the musical material and the procedures employed in much post-Webernian music precludes the use of many of the controls found in Webern, but that other methods of determining the listener's response to the music can be found in some of the works of the post-Webernian composers. It argues, however, that in some post-Webernian music, and particularly in that composed using chance or serial methods, the listener's response to the music may not be determined by the composer. The thesis claims' that many of the important formal problems facing post-Webernian music must be considered in relation to the problems of auditory perception

Transformer Oil Passivation and Impact of Corrosive Sulphur

In recent years a significant volume of research has been undertaken in order to understand the recent failures in oil insulated power apparatus due to deposition of copper sulphide on the conductors and in the insulation paper. Dibenzyl Disulfide (DBDS) has been found to be the leading corrosive sulphur compound in the insulation oil [1]. The process of copper sulphide formation and the deposition in the paper is still being investigated, but a recently proposed method seems to be gaining some confidence [1]. This method suggests a two-step process; initially the DBDS and some oil soluble copper complexes are formed. Secondly the copper complexes are absorbed in the paper insulation, where they then decompose into copper sulphide [2]. The most commonly used mitigating technique for corrosive sulphur contaminated oil is passivation, normally using Irgamet 39 or 1, 2, 3-benzotriazole (BTA). The passivator is diluted into the oil to a concentration of around 100ppm, where it then reacts with the copper conductors to form a complex layer around the copper, preventing it from interacting with DBDS compounds and forming copper sulphide. This research project will investigate the electrical properties of HV transformers which have tested positive for corrosive sulphur, and the evolution of those properties as the asset degrades due to sulphur corrosion. Parallel to this the long term properties of transformers with passivated insulation oil will be analysed in order to understand the passivator stability and whether it is necessary to keep adding the passivator to sustain its performance. Condition monitoring techniques under investigation will include dielectric spectroscopy, frequency response analysis, recovery voltage method (aka interfacial polarisation) amongst others. Partial discharge techniques will not be investigated, as the voltage between the coil plates is low and therefore it will not contribute significantly to the overall insulation breakdown, in corrosive oil related faults [3]. The goal of this research is to establish key electrical properties in both passivated and non-passivated power transformers that demonstrate detectable changes as the equipment degrades due to the insulation oil being corrosive