ALBERT

Description: Journal of the American Chemical Society DOI: 10.1021/jacs.6b03166

Description: The Betic Ophiolites consist of numerous tectonic slices, metric to kilometric in size, of eclogitized mafic and ultramafic rocks associated to oceanic metasediments, deriving from the Betic oceanic domain. The outcrop of these ophiolites is aligned along 250 km in the Mulhacén Complex of the Nevado-Filábride Domain, located at the center-eastern zone of the Betic Cordillera (SE Spain). According to petrological/geochemical inferences and SHRIMP (Sensitive High Resolution Ion Micro-Probe) dating of igneous zircons, the Betic oceanic lithosphere originated along an ultra-slow mid-ocean ridge, after rifting, thinning and breakup of the preexisting continental crust. The Betic oceanic sector, located at the westernmost end of the Tethys Ocean, developed from the Lower to Middle Jurassic (185–170 Ma), just at the beginning of the Pangaea break-up between the Iberia-European and the Africa-Adrian plates. Subsequently, the oceanic spreading migrated northeastward to form the Ligurian and Alpine Tethys oceans, from 165 to 140 Ma. Breakup and oceanization isolated continental remnants, known as the Mesomediterranean Terrane, which were deformed and affected by the Upper Cretaceous-Paleocene Eo-Alpine high-pressure metamorphic event, due to the intra-oceanic subduction of the Jurassic oceanic lithosphere and the related continental margins. This process was followed by the partial exhumation of the subducted oceanic rocks onto their continental margins, forming the Betic and Alpine Ophiolites. Subsequently, along the Upper Oligocene and Miocene, the deformed and metamorphosed Mesomediterranean Terrane was dismembered into different continental blocks collectively known as AlKaPeCa microplate (Alboran, Kabylian, Peloritan and Calabrian). In particular, the Alboran block was displaced toward the SW to occupy its current setting between the Iberian and African plates, due to the Neogene opening of the Algero-Provençal Basin. During this translation, the different domains of the Alboran microplate, forming the Internal Zones of the Betic and Rifean Cordilleras, collided with the External Zones representing the Iberian and African margins and, together with them, underwent the later alpine deformation and metamorphism, characterized by local differences of P-T (Pressure-Temperature) conditions. These Neogene metamorphic processes, known as Meso-Alpine and Neo-Alpine events, developed in the Nevado-Filábride Domain under Ab-Ep amphibolite and greenschists facies conditions, respectively, causing retrogradation and intensive deformation of the Eo-Alpine eclogites.

Description: Surface permanent-magnet machines are widely used in different applications, from industrial automation to home appliance and electrical traction. Among any possible machine topology, the fractional-slot surface permanent-magnet one has gained increasing importance, because of its high torque density, low cogging torque, extended flux weakening capability and high efficiency. In addition, fractional-slot machines are attractive for tooth concentrated windings, which allow some optimized manufacturing solutions such as modular stator tooth and high slot filling factor, which result in copper volume reduction; cost reduction, and lower stator parasitic resistances. The slot–pole combination is one of the most important design parameter and, as shown in this paper, it affects performances and the robustness of the machine with respect to the manufacturing imperfections. In the literature, slot–pole combinations are optimized at design phase by finite-element analysis relying on a healthy machine model. The original contribution of this paper is a design for reliability method that models manufacturing defects and includes them at design phase in the optimization process of slot–pole combinations. A method is presented that allows defining the optimal design parameters for maximum performances and robustness towards unavoidable imperfections caused by tolerances of the manufacturing process.