The Living Application: a Self-Organising System for Complex Grid Tasks

We present the living application, a method to autonomously manage applications on the grid. During its execution on the grid, the living application makes choices on the resources to use in order to complete its tasks. These choices can be based on the internal state, or on autonomously acquired knowledge from external sensors. By giving limited user capabilities to a living application, the living application is able to port itself from one resource topology to another. The application performs these actions at run-time without depending on users or external workflow tools. We demonstrate this new concept in a special case of a living application: the living simulation. Today, many simulations require a wide range of numerical solvers and run most efficiently if specialized nodes are matched to the solvers. The idea of the living simulation is that it decides itself which grid machines to use based on the numerical solver currently in use. In this paper we apply the living simulation to modelling the collision between two galaxies in a test setup with two specialized computers. This simulation switces at run-time between a GPU-enabled computer in the Netherlands and a GRAPE-enabled machine that resides in the United States, using an oct-tree N-body code whenever it runs in the Netherlands and a direct N-body solver in the United States.Comment: 26 pages, 3 figures, accepted by IJHPC

Narrow optical gap ferroelectric Bi2ZnTiO6 thin films deposited by RF sputtering

This work reports the deposition of single phase Bi2ZnTiO6 thin films onto Pt/Si-based substrates using the RF-sputtering method and the respective structural, morphological, optical and local ferroelectric characterization. The thin film grows in the polycrystalline form with tetragonal P4mm symmetry identified by X-ray diffraction. The lack of a spatial inversion centre was confirmed by the second harmonic generation. A narrow indirect optical gap of 1.48 eV was measured using optical diffuse reflectance. The ferroelectric domain reversal was further demonstrated through piezo-response force microscopy. This work demonstrates a practical method to fabricate the BZT perovskite phase, without resorting to high pressure and temperature conditions necessary to synthetize the bulk form, with outstanding optical and ferroelectric properties.This work was supported by national funds through the Portuguese Foundation for Science and Technology (FCT/MEC) and COMPETE 2020. when appropriate, co-financed by FEDER under the PT2020 Partnership Agreement: Grants SFRH/BPD/80663/2011 and SFRH/BPD/92896/2013; Projects IFIMUP-IN:Norte-070124-FEDER-000070; CICECO-AIM: POCI-01-0145- FEDER-007679, PTDC/FIS-NAN/0533/2012, UID/CTM/50011/2013, UID/FIS/04650/2013, CERN/FIS/NUC/0004/2015 and NECL: NORTE-01-0145-FEDER-022096 and UID/NAN/50024/2019. Foundation CAPES through the project PNPD-UFAM/Física/1671526 is also acknowledged