112,692 research outputs found
Analisi (critica) del discorso normativo sulla situazione penitenziaria delle persone trans all’estero
No full textTestimonianze epigrafiche per una sintesi sulla proprietá imperiale nel territorio riminese
No full textTemperature Distribution along an Outdoor Insulator Subjected to Different Pollution Levels
No full textThe appearance of dry bands on polluted insulator surfaces may cause the ignition of electrical arcs, which in turn give rise to tracking and erosion, or may elongate until they bridge the electrodes causing flashover. Efficient models able to predict the occurrence of such a severe problem are of paramount importance for the engineer involved in the design of power line insulation. The present paper concerns the evaluation of the temperature distribution along the surface of an outdoor insulator subjected to pollution of different severity in order to predict dry band formation. The proposed numerical procedure, based on the joint solution of Maxwell equations in their quasi-static formulation and thermal equations, has been applied to study the case of a suspension cap-and-pin glass insulator, covered with pollution layers of different conductivity and thickness. The dependence of the conductivity of the layer on the temperature has been taken into account properly. The influence of uniform and nonuniform pollution distribution on the temperature profile is discussed for an applied sinusoidal power frequency voltag
On the effect of anisotropy in nonlinear composite materials for stress grading applications: a numerical study
No full textNumerical analysis of performances of stress grading cable accessories made of different anisotropic composite materials
No full textStress control tubes made out of composite materials characterized by nonlinear and anisotropic electric properties, are widely adopted for the realization of cable accessories, in order to achieve an efficient stress control. In this paper a numerical model, able to take into account both anisotropy and nonlinearity of stress grading composites, will be used to investigate on the effect of the different properties on the field distribution inside cable terminations
Dispersione di ossitetraciclina nell'ambiente in seguito a trattamento dei vitelli
No full textDopo aver trattato dei vitelli con 60 mg/kg di ossitetraciclina per cinque giorni, il farmaco e' stato rintracciato nelle feci, nella lettiera e nel letame. Il tempo di cinque mesi necessario per la maturazione del letame consente una degradazione adeguata ed e' sufficiente per minimizzare l'impatto ambientale del farmac
VALUTAZIONI SUL CONTENUTO RUMINALE DI VITELLI SOTTOPOSTI AD ALIMENTAZIONI DIVERSE
No full textAbbiamo ritenuto opportuno valutare le caratteristiche del contenuto ruminale in vitelli clinicamente sani in vari momenti dello sviluppo, della produttività ed in rapporto ad alimentazioni diverse, a completamento di una ricerca nella quale erano stati controllati numerosi parametri ematici.
Physical aspects, pH values, protozoa and bacteria of the rumen fluid in calves diversely fed were investigated
EM Fields Generated by Lightning Channels with Arbitrary Location and Slope
No full textIt is well known that lightning discharges follow a tortuous path; therefore, a general technique able to evaluate the electromagnetic (EM) fields associated with discharge currents flowing into tortuous channels seems to be worthy of consideration. Two techniques have been adopted to find the EM field generated by a current pulse traveling along a single line radiator with arbitrary slope and location above the ground. The first one employs the Fraunhofer approximation, which can provide useful information only on distant radiated fields. The second technique is exact, but applies only to the case of a velocity of propagation v of the current pulse equal to c (velocity of light). Even this solution is indeed inadequate for our purposes since v<c, as evidenced in the literature. In this paper, we evaluate the EM field associated to an arbitrarily oriented radiator without making any mathematical approximation in order to obtain closed-form solutions for the fields. A schematic square-pulse representation of the current and charge distributions along the discharge channels are adopted. The fields due to arbitrary time-varying sources are obtained adopting a suitable convolution integratio
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