Kooperative Lernanlässe zur Verbesserung der Konnektivität im dualen System

Die Kooperation der Lernorte des dualen Systems stellt ein grundlegendes Qualitätsmerkmal der Lehrlingsausbildung dar. Empirische Studien aus Österreich und Deutschland zeigen, dass es bei der Abstimmung und Zusammenarbeit zwischen den Lernorten Berufsschule und Betrieb Potenzial zur Verbesserung gibt. Im Rahmen dieses Beitrags wird die Kooperation zwischen den Lernorten des dualen Systems auf der Ebene der Lehr-/Lernprozesse näher beleuchtet. Dabei wird im ersten Schritt die Frage nach den Voraussetzungen für eine erfolgreiche Realisierbarkeit kooperativer Lernanlässe gestellt. Durch einen explorativen Forschungsansatz konnte mithilfe von qualitativen Interviews ein erster Einblick in die aktuelle Situation gewonnen werden. Dabei konnte die Expertise aller involvierten Lernorte, ergo inklusive der Lernorte für die Trainerinnen und Trainer (WIFI) und Berufsschullehrkräfte (PH), eingefangen werden. Auf Basis der durch das Autorenteam erarbeiteten Forschungsergebnisse wurde anhand von drei Gestaltungsansätzen der weitere Forschungsweg festgelegt: (1) Entwicklung kooperativer Lernanlässe auf der Mikroebene gemeinsam mit den lehrenden Akteurinnen und Akteuren, (2) Integration des Themas Lernortkooperation in die Ausbildung der jeweils lehrenden Akteurinnen und Akteure und (3) Verankerung in den Lehrplänen und Ausbildungsordnungen (Mesoebene)

Editorial: Videos in der (Hochschul-)Lehre

24.04.2014 | Thomas Antretter, Johannes Dorfinger, Martin Ebner, Michael Kopp, Walther Nagler, Jutta Pauschenwein, Michael Raunig, Manfred Rechberger, Herwig Rehatschek, Patrick Schweighofer, Reinhard Staber & Martin Teufel (Graz

Concave Plasmonic Particles: Broad-Band Geometrical Tunability in the Near Infra-Red

Optical resonances spanning the Near and Short Infra-Red spectral regime were exhibited experimentally by arrays of plasmonic nano-particles with concave cross-section. The concavity of the particle was shown to be the key ingredient for enabling the broad band tunability of the resonance frequency, even for particles with dimensional aspect ratios of order unity. The atypical flexibility of setting the resonance wavelength is shown to stem from a unique interplay of local geometry with surface charge distributions

Transition from localized surface plasmon resonance to extended surface plasmon-polariton as metallic nanoparticles merge to form a periodic hole array

W. Andrew Murray, Simion Astilean, and William L. Barnes, Physical Review B, Vol. 69, article 165407 (2004). "Copyright © 2004 by the American Physical Society."We present results of experiments to determine the dispersion of the plasmon modes associated with periodic silver nanoparticle and nanohole arrays fabricated using an extension of the nanosphere lithography technique. Ordered monolayers of polystyrene nanospheres were used as a deposition mask through which silver was deposited by thermal evaporation, subsequent removal of the nanospheres thus leaving an array of metallic nanoparticles. By reactive-ion etching of the nanospheres in an oxygen plasma prior to silver deposition, arrays consisting of particles of increasing size were fabricated. The extremities of the particles eventually merge to create a continuous metallic network perforated by subwavelength holes, thus allowing a study of the particle-hole transition. Combining optical measurements of transmittance and reflectance with information gained using scanning electron microscopy, three separate regimes were observed. For low etch times the samples comprise mainly individual nanoparticles and the optical response is dominated by localized surface plasmon resonances that show no dispersion. As the etch time is increased almost all of the nanoparticles merge with adjacent particles, although many defects are present—notably where some particles fail to merge, a small gap being left between them. The presence of these defects prevents an abrupt structural transition from metallic nanoparticles to a continuous metallic film perforated by an array of nanoholes. The presence of such gaps also results in dispersion data that lack clearly defined features. A further increase in etch time leads to samples with no gaps: instead, a continuous metal film perforated by a nanohole array is produced. The optical response of these structures is dominated by extended surface plasmon-polariton modes

Development of robust metal-supported SOFCs and stack components in EU METSAPP consortium

The potential of MS-SOFCs was demonstrated through the previous EU METSOFC project, which concluded that the development of oxidation resistant novel metal-supported solid oxide fule cell (MS-SOFC) design and stack is the requirement to advance this technology to the next level. The following EU METSAPP project has been executed with an overall aim of developing advanced metal-supported cells and stacks based on a robust, reliable and up-scalable technology. During the project, oxidation resistant nanostructured anodes based on modified SrTiO3 were developed and integrated into MS-SOFCs to enhance their robustness. In addition, the manufacturing of metal-supported cells with different geometries, scalability of the manufacturing process was demonstrated and more than 200 cells with an area of ∼150 cm2 were produced. The electrochemical performance of different cell generations was evaluated and best performance and stability combination was observed with doped SrTiO3 based anode designs. Furthermore, numerical models to understand the corrosion behavior of the MS-SOFCs were developed and validated. Finally, the cost effective concept of coated metal interconnects was developed, which resulted in 90% reduction in Cr evaporation, three times lower Cr2O3 scale thickness and increased lifetime. The possibility of assembling these cells into two radically different stack designs was demonstrated

Practical Electromagnetic Template Attack on HMAC

The original publication is available at www.springerlink.comInternational audienceIn this paper, we show that HMAC can be attacked using a very efficient side channel attack which reveals the Hamming distance of some registers. After a profiling phase which requires access to a similar device that can be configured by the adversary, the attack recovers the secret key on one recorded execution of HMAC-SHA-1 for example, on an embedded device. We perform experimentations using a NIOS processor executed on a Field Programmable Gate Array (FPGA) to confirm the leakage model. Besides the high efficiency of this attack, $2^32\cdot 3^k$ where $k$ is the number of 32-bit words of the key, that we tested with experimentations, our results also shed some light on the on the requirements in term of side channel attack for the future SHA-3 function. Finally, we show that our attack can also be used to break the confidentiality of network protocols usually implemented on embedded devices. We have performed experiments using a NIOS processor executed on a Field Programmable Gate Array (FPGA) to confirm the leakage model. We hope that our results shed some light on the requirements in term of side channel attack for the future SHA-3 function

Mode imaging and selection in strongly coupled nanoantennas

The number of eigenmodes in plasmonic nanostructures increases with complexity due to mode hybridization, raising the need for efficient mode characterization and selection. Here we experimentally demonstrate direct imaging and selective excitation of the bonding and antibonding plasmon mode in symmetric dipole nanoantennas using confocal two-photon photoluminescence mapping. Excitation of a high-quality-factor antibonding resonance manifests itself as a two-lobed pattern instead of the single spot observed for the broad bonding resonance, in accordance with numerical simulations. The two-lobed pattern is observed due to the fact that excitation of the antibonding mode is forbidden for symmetric excitation at the feedgap, while concomitantly the mode energy splitting is large enough to suppress excitation of the bonding mode. The controlled excitation of modes in strongly coupled plasmonic nanostructures is mandatory for efficient sensors, in coherent control as well as for implementing well-defined functionalities in complex plasmonic devices.Comment: 11 pages, 5 figures, 1 supplementary informatio