Anotaciones a la tribu Stipeae (Gramineae) para Andalucía oriental (España)

Anotaciones a la tribu Stipeae (Gramineae) para Andalucía Oriental (España). El estudio taxonómico de los materiales de la tribu Stipeae (Gramineae) procedentes de Andalucía Oriental (España), ha revelado la presencia de dos nuevos taxones, posiblemente endémicos para el área: Macrochloa tenacissima subsp. umbrosa F.M. Vázquez subsp. nov y Stipa almeriensis F.M. Vázquez sp. nov. Además, se incluye una nueva combinación: Macrochloa antiatlantica (Barreña, D. Rivera, Alcaraz & Obón) F. M. Vázquez, comb. nov

Tunable asymmetric magnetoimpedance effect in ferromagnetic NiFe/Cu/Co films

We investigate the magnetization dynamics through the magnetoimpedance effect in ferromagnetic NiFe/Cu/Co films. We observe that the magnetoimpedance response is dependent on the thickness of the non-magnetic Cu spacer material, a fact associated to the kind of the magnetic interaction between the ferromagnetic layers. Thus, we present an experimental study on asymmetric magnetoimpedance in ferromagnetic films with biphase magnetic behavior and explore the possibility of tuning the linear region of the magnetoimpedance curves around zero magnetic field by varying the thickness of the non-magnetic spacer material, and probe current frequency. We discuss the experimental magnetoimpedance results in terms of the different mechanisms governing the magnetization dynamics at distinct frequency ranges, quasi-static magnetic properties, thickness of the non-magnetic spacer material, and the kind of the magnetic interaction between the ferromagnetic layers. The results place ferromagnetic films with biphase magnetic behavior exhibiting asymmetric magnetoimpedance effect as a very attractive candidate for application as probe element in the development of auto-biased linear magnetic field sensors.Comment: 5 figure

Gravitational Lorentz Violations from M-Theory

In an attempt to bridge the gap between M-theory and braneworld phenomenology, we present various gravitational Lorentz-violating braneworlds which arise from p-brane systems. Lorentz invariance is still preserved locally on the braneworld. For certain p-brane intersections, the massless graviton is quasi-localized. This also results from an M5-brane in a C-field. In the case of a p-brane perturbed from extremality, the quasi-localized graviton is massive. For a braneworld arising from global AdS_5, gravitons travel faster when further in the bulk, thereby apparently traversing distances faster than light.Comment: 13 pages, 1 figure, LaTeX, references added, minor corrections and addition

Contribución a la caracterización químico-mineralógica de los esquistos del "Complejo de Ordes"

[Resumen] Se presentan los datos qUlmlcos y mineralógicos de 77 muestras de rocas esquistosas de la "Unidad Betanzos-Arzúa", perteneciente al "Complejo de Ordes" , con objeto de analizar la variabilidad existente y discutir las posibilidades de sectorización de los distintos tipos de rocas en función de parámetros de composición.[Abstract] This paper presents the chemical and mineralogical composi tion of 77 samples of schi ts belonging to the "Unit of Betanzos-Arzua" , included in the "Ordenes Complex" . Tqe data were used to make an analysis the variability in the composi tion of the rocks and a subdivision of the " Unidad " based on the rock characteristics was intented