Biagi R.,University of Modena and Reggio Emilia |
Biagi R.,CNR Institute of Neuroscience |
Fernandez-Rodriguez J.,European Synchrotron Radiation Facility |
Gonidec M.,Campus de la UAB |
And 10 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2010
Bisphthalocyaninato terbium complexes show a long magnetization relaxation time at relatively high temperatures-which makes them very interesting as magnets at single-molecule level. Their technological exploitation, however, requires the addressing of the individual molecules, therefore the deposition of single-molecule magnets on surfaces is a topic of great interest as the interaction with the substrate can play a crucial role in the definition of the molecule properties. In this work we investigate the electronic and magnetic properties of anionic and neutral forms of a bis(phthalocyaninato)terbium derivative deposited on graphite by means of x-ray absorption spectroscopy and x-ray magnetic circular dichroism, performed at low temperature and high magnetic field at the M4,5 edge of Tb. We were able to reproduce the experimental spectra by means of multiplet calculations and to validate the applicability of sum rules to the present case. Sum rules were then used for determining the orbital and spin moments of thick (several monolayers) and of thin films (submonolayer range). Calculations of spectra as a function of the molecule orientation with respect to the impinging x-ray beam, allowed us to ascertain the adsorption geometry of molecules. For both compounds, molecules stay essentially flat when adsorbing as thin film on graphite. This result is also confirmed by scanning probe microscopy, which also finds a very interesting ordered arrangement for the molecules of the neutral form. In the thick film of the neutral compound the molecules keep the same orientational order, arranging almost flat as well. On the contrary, in the thick film of the anionic compound their orientation appears to be random. The origin of this different behavior can be related to the hindrance of the counterion moiety and/or to the different solvent used for each compound. Finally, the comparison of the magnetization values and their dependence on the external magnetic field and temperature suggest that the magnetic properties of molecules are preserved when adsorbed onto the graphite surface. © 2010 The American Physical Society.
Ribes A.,Campus de la UAB |
Ribes A.,Imperial College London |
Cerquides J.,Campus de la UAB |
Demiris Y.,Imperial College London |
De Mantaras R.L.,Campus de la UAB
IEEE-RAS International Conference on Humanoid Robots | Year: 2015
Nowadays robots are becoming more ubiquitous, and focus is increasingly put on the variety of tasks they can perform autonomously. However, due to the dynamics of the environment or the robot itself, sometimes the models that were learned in the past do not exactly fit in the present situation. Adaptation mechanisms are of key importance in this case since they enable the robot to reuse prior knowledge, which is useful for the current context. In this work we introduce an active adaptation mechanism which enables a humanoid robot to recover from a failure, exemplified as a displacement of the object it is interacting with. © 2015 IEEE.
Alvaro S.,Campus de la UAB
Artnodes | Year: 2013
Developments in recent years in electronic art and the new media can be characterized in many ways, among them with discourses based on their development in parallel with the technologies they use or based on the development of specific features such as interactivity, communication, synaesthesia and their relationship with the virtual. This article proposes a hybrid perspective, along the lines of the discourse of Edward Shanken, with new media art and contemporary art - especially as related to vanguard movements such as kinetic art, conceptual art, performance, the Fluxus movement, Dadaism, Situationism and experimental film - being more simultaneous than continuous. Media art and contemporary art both develop from a topological thought - as expressed by authors like Bergson, Deleuze, Serres, Agamben and Latour - that is pushed into movement. Objects and stable boundaries disappear and we have, rather, a complex world, with relationships, intensities and connections as defining elements and with an ability to simultaneously generate new, mutable territories. In this setting, life feeds on information exchange and art leaves behind the stable place it formerly inhabited to venture into the creation of new contexts and forms of interaction and the production of emergent meanings, and taking account of the kinetic and immersive spaces of multimedia installations, urban space and virtual and ubiquitous web space, the coexistence of urban and web space in augmented reality, and, finally, the ecology of a connected world where technology, life, culture, nature and the local - with its global implications - are all brought together.