In this book, José Luis Bermúdez addresses two fundamental problems in the philosophy and psychology of self-consciousness: (1) Can we provide a noncircular account of fully fledged self-conscious thought and language in terms of more fundamental capacities? (2) Can we explain how fully fledged self-conscious thought and language can arise in the normal course of human development? Bermúdez argues that a paradox (the paradox of self-consciousness) arises from the apparent strict interdependence between self-conscious thought and linguistic self-reference. The paradox renders circular all theories that define self-consciousness in terms of linguistic mastery of the first-person pronoun. It seems to follow from the paradox of self-consciousness that no such account or explanation can be given. Drawing on recent work in empirical psychology and philosophy, the author argues that any explanation of fully fledged self-consciousness that answers these two questions requires attention to primitive forms of self-consciousness that are prelinguistic and preconceptual. Such primitive forms of self-consciousness are to be found in somatic proprioception, the structure of exteroceptive perception, and prelinguistic forms of social interaction. The author uses these primitive forms of self-consciousness to dissolve the paradox of self-consciousness and to show how the two questions can be given an affirmative answer. Bradford Books imprint
The salient issues related to lightning protection of long wind-turbine blades are discussed in this paper. We show that the lightning protection of modern wind turbines presents a number of new challenges due to the geometrical, electrical, and mechanical particularities of the turbines. The risk assessment for the lightning-protection-system design is solely based today on downward flashes. We show in this paper that the majority of the strikes to modern turbines are expected to be upward lightning. Neglecting upward flashes, as implicitly done by the International Electrotechnical Commission, might result in an important underestimation of the actual number of strikes to a tall wind turbine. In addition, we show that the rotation of the blades may have a considerable influence on the number of strikes to modern wind turbines as these may be triggering their own lightning. Because wind turbines are tall structures, the lightning currents that are injected by return strokes into the turbines will be affected by reflections at the top, bottom, and junction of the blades with the static base of the turbine. This is of capital importance when calculating the protection of internal circuitry that may be affected by magnetically induced electromotive forces that depend directly on the characteristics of the current in the turbine. The presence of carbon-reinforced plastics (CRP) in the blades introduces a new set of problems to be dealt with in the design of the turbines' lightning protection system. One problem is the mechanical stress resulting from the energy dissipation in CRP laminates due to the circulation of eddy currents. We evaluate in this paper the dissipated energy and propose recommendations as to the number of down conductors and their orientation with respect to the CRP laminates so that the dissipated energy is minimized. It is also emphasized that the high static fields under thunderclouds might have an influence on the moving carbon-fiber parts. This issue needs to be addressed by lightning protection researchers and Manuscript engineers. Representative full-scale blade tests are still complex because lightning currents from an impulse current generator are conditioned to the electrical characteristics of the element under test and return paths. It is therefore desirable to complement laboratory tests with theoretical and computer modeling for the estimation of fields, currents, and voltages within the blades.
[1] On the basis of a distributed-source representation of the lightning channel, the mathematical formulations of the so-called engineering lightning return stroke models are generalized to take into account the presence of a vertically extended strike object. The strike object is modeled as a lossless uniform transmission line, and the reflection coefficients are all assumed to be constant. The distribution of current along the lightning channel for each model is expressed in terms of the ''undisturbed'' current, object height, and current reflection coefficients at the top and the bottom of the object. The undisturbed current is defined as the current that would flow in the channel if the current reflection coefficients at the extremities of the strike object were equal to zero, that is, the characteristic impedances of the lightning channel and the strike object were equal to each other and equal to the grounding impedance of the strike object. The distributedsource representation of the lightning channel adopted in this study allows for a more general and straightforward formulations of the generalized return-stroke models than the traditional representations implying a lumped current source at the bottom of the channel, including a self-consistent treatment of the impedance discontinuity at the tower top.
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