Soft spin waves and magnetization reversal in elliptical permalloy nanodots: Experiments and dynamical matrix results

We present an experimental and theoretical investigation of magnetization reversal in Permalloy elliptical nanodots under the application of a varying (quasistatic) magnetic field directed along the hard (short) and easy (long) axes of the ellipses. The magnetic response of the particles is investigated with the magneto-optic Kerr effect (MOKE) and Brillouin scattering (BLS). Experimental MOKE results are reproduced by micromagnetic simulations. The spectrum of the normal modes, calculated with the dynamical matrix method, reproduces the BLS results. We find that when an abrupt magnetization switching occurs it is accompanied by a soft magnetic mode (different in the two cases), the symmetry of which determines the initial steps (onset) of the microscopic reversal path

Online Learning Support in a Ubiquitous Learning Environment

The ubiquitous learning environment (ULE) is both an ontological and epistemological problem. For most scholars, ULE provides an interoperable, pervasive, and seamless learning architecture to connect, integrate, and share three major dimensions of learning resources: learning collaborators, learning contents, and learning services. Furthermore, ULE is described as an educational paradigm that mainly uses technology for curriculum delivery. Through reflection and exploration, this chapter argues that online learning support has a symbiotic relationship with ULE because the student, at some point, should move beyond the “text” level into concepts and conceptual organization schemes (ontologies). In line with this viewpoint, this chapter problematizes the gap created by real-world and digital-world resources—and argues that online learning support for teaching and learning processes have not yet emulated ULE as an important pedagogical resource.Institute for Open and Distance Learning (IODL