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[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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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.

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Philosophers have often argued that ascriptions of content are appropriate only to the personal level states of folk psychology. Against this, this paper defends the view that the familiar propositional attitudes and states defined over them are part of a larger set of cognitive processes that do not make constitutive reference to concept possession. It does this by showing that states with nonconceptual content exist both in perceptual experience and in subpersonal information-processing systems. What makes these states content-involving is their satisfaction of certain basic conditions deriving from a eneral account of representation-driven behaviour that is neutral on the question ofconcept possession. It is also argued that creatures can be in states with nonconceptual content even though they possess no conceptual abilities at all.How distinctive are the cognitive processes, such as beliefs, desires, hopes and fears, which constitutively involve the possession of concepts? Recent work in philosophy, psychology and cognitive science has suggested that there might be various types of cognitive state that possess content although they do not require possession of the concepts needed to specify that content.

Summary In ferrets, the selective 5-hydroxytryptamine (5-HT) 5-HT3 receptor antagonist BRL 43694 given as a single injection (0.05-0.5 mg kg-1 i.v.) before cisplatin, or by divided dose (2 x 0.005-2 x 0.5 mg kg-I i.v.) before and after cisplatin dramatically reduced or abolished the severe cisplatin-induced vomiting. BRL 43694 also substantially reduced the vomiting induced by cyclophosphamide: doxorubicin, and prevented the trimelamol-induced emesis. The severe emesis caused by whole body exposure to X-irradiation was prevented by intravenous or oral BRL 43694. A single i.v. dose of BRL 43694 given during an emetic episode or within the peak emetic period, abolished the vomiting induced by the cytotoxic drugs and by X-irradiation, usually within 30s. Where the induction of emesis was prevented or subsequently abolished by BRL 43694, the associated behaviour (subjectively assessed as nausea) was also absent or greatly attenuated. BRL 43694 (0.1 mg kg-1 i.v.) did not affect the emesis evoked in dogs by the dopamine agonist apomorphine. The potent anti-emetic activity of BRL 43694 is discussed in terms of potential clinical use, and of the fundamental role that 5-HT3 receptors may play in the mechanisms of nausea and vomiting.High intravenous doses of metoclopramide (Maxolon; Beecham Pharmaceuticals) are used in the management of nausea and vomiting in man. and Miner et al. (1987) Induction of emesis Emesis was induced by i.v. injection of cisplatin (10mg kg-1), or cyclophosphamide (80mg kg-1) with doxorubicin (6mg kg-1), or by intraperitoneal (i.p.) injection of trimelamol (50mg kg-1). For trimelamol, the i.p. route of injection was preferred over the i.v. route because dimethylsulphoxide (DMSO) was required as the solvent. These doses of cytotoxic drugs were the lowest required to cause repeated and reproducible vomiting. In the experiments with dogs, apomorphine (0.1 mg kg-1) was injected subcutaneously.To evoke emesis by X-irradiation, ferrets were closely confined in a ventilated box constructed of perspex 1 mm thick. X-rays were derived from the tungsten anode of a Machlett Model OEG-50 X-ray supply, operating at 50kV and 20 mA through a berylium window with a 0.18mm aluminium filter and placed about 25cm above the ferret. This low energy X-ray beam was just sufficient to cause reproducible emesis; exposure time was 10.4 min.Observations Ferrets given cisplatin or cyclophosphamide and doxorubicin were observed for the onset of emesis (latency period) and the number of emetic episodes over 240 min after injection. Emesis had usually ceased in control animals within this period. The observation period following trimelamol was 210min, minimising any discomfort caused by the i.p. injection of the large volume of trimelamol and solvent. For dogs given apomorphine, the observation period was 30min. The observation period following X-irradiation was 120 min, since in control animals, emesis had ceased within this time. Untreated ferrets were observed for 240 min.In some experiments, additional behavioural events ...