Modern telecommunication satellites can benefit from the features of fiber optic sensing wrt to mass savings, improved performance and lower costs. Within the course of a technology study, launched by the European Space Agency, a fiber optic sensing system has been designed and is to be tested on representative mockups of satellite sectors and environment.

Availability of reliable flight sensor data and knowledge of the structural behaviour are essential for safe operation of the Ariane launcher. The Ariane launcher is currently monitored by hundreds of electric sensors during test and qualification. Fibre optic sensors are regarded as a potential technique to overcome limitations of recent monitoring systems for the Ariane launcher [1]. These limitations include cumbersome application of sensors and harness as well as a very limited degree of distributed sensing capability. But, in order to exploit the various advantages of fibre optic sensors (high degree of multiplexing, distributed sensing capability, lower mass impact, etc.) dedicated measurement systems have to be developed and investigated. State-of-the-art fibre optic measurement systems often use free beam setups making them bulky and sensitive to vibration impact. Therefore a new measurement system is developed as part of the ESAstudy [2].

Alle Programme, die auf Computern und Mikrochips ausgeführt werden, auch Krypto- Algorithmen, beeinflussen physikalische Parameter der Hardware wie zum Beispiel den Stromverbrauch. Über solche sogenannten Seitenkanäle können Geheimnisse, die auf einem Chip verarbeitet werden, wie z. B. kryptographische Schlüssel, extrahiert werden. Um zu sicheren Implementierungen zu gelangen, muss dieser Angriffspfad berücksichtigt und entsprechende Gegenmaßnahmen während der Entwicklung getroffen werden.

Thin MnSi films have been prepared on Si(111) by molecular beam epitaxy under simultaneous evaporation of Mn and Si. RHEED analysis in combination with TEM investigation reveals that this codeposition technique leads to smooth films. Resistivity measurements show a metallic behavior that is qualitatively the same as for bulk MnSi. The magnetic ordering temperature T-ord of 43 K, which has been determined from resistivity data and by SQUID magnetometry, is considerably enhanced compared to the bulk value. For the thinnest films, however, a decrease of T-ord is observed which is explained by the reduction of the spin-spin interaction near the surfaces of the film. Recently, it has been stated, that the spin-spin correlation length is much larger than known from other itinerant magnetic materials. In contrast, we show that the coupling range can be estimated as 7 monolayers and does not exceed the values of common magnets.

In FDTC 2009, Li et al. published a DFA attack [20] against the symmetric block cipher SHACAL1 [11]. This block cipher substantially consists of the compression function of the hash function SHA1 [16] except for the final addition operation. When using the SHA1 compression function as a primitive in a keyed hash function like HMAC-SHA1 [17] or in a key derivation function it might be of some interest if the attack of Li et al. also applies to the SHA1 compression function. However, the final addition operation turns out to completely prevent this direct application. In this paper we extend the attack of Li et al. in order to overcome the problem of the final addition and to extract the secret inputs of the SHA1 compression function by analysing faulty outputs. Our implementation of the new attack needs about 1000 faulty outputs and a computation time of three hours on a normal PC to fully extract the secret inputs with high probability.

GaInN/GaN multiple quantum well structures grown on polar and nonpolar surfaces have been compared with respect to the indium incorporation efficiency in the quantum wells (QWs). Under the same growth conditions X‐ray diffraction measurements reveal similar growth rates and In concentrations for c‐plane, a‐plane, and m‐plane with In contents up to 40%. These results are in good agreement with optical experiments, in particular for homoepitaxial growth. However, there is strong evidence that the optical properties of the nonpolar heteroepitaxial GaInN QWs are dominated by the high density of stacking faults in those samples.

Force-torque sensors are key elements in modern force feedback and robotic control applications. For special applications resistance against electromagnetic interference, high amount of load cycles or chemical resistance are important. For these applications, fiber-Bragg-grating based force torque sensors have been seen as possible solutions. Yet the implementation of a force-torque-sensor with six degrees of freedom and well conditioned sensitivities is still lacking demonstration. In this work, we demonstrate the design of a miniaturized fiber-Bragg-grating based force-torque sensor with six degrees of freedom using a numerical nonlinear programming technique. We implement the optimized structure and show its feasibility and sensitivity.

Using time-resolved photoluminescence spectroscopy on GaInN/GaN multiple quantum well structures, we analyze the radiative and nonradiative processes contributing to the "green gap" in GaN-based light emitting devices. We observe that it is only partly caused by a reduced oscillator strength due to the Quantum Confined Stark Effect (QCSE) which becomes stronger with increasing indium concentration and well width.As the dominant effect we observe a reduction of nonradiative lifetimes when the indium concentration is increased. For higher indium concentrations, we find an additional nonradiative recombination path that might be attributed to an increased generation of defects like misfit dislocations, nitrogen vacancies and/or indium clusters within the optically active region. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Fiber-optic sensors have experienced great interest in research and development since their invention. Dedicated measurement systems are essential for utilization and development of these sensors. Instruments based on tunable lasers are established devices for the demodulation of such sensors. We introduce and demonstrate a tunable laser measurement system based on a widely tunable monolithic laser diode (TML). It is capable of demodulating different types of fiber-optic sensors, although we focus on the interrogation of fiber Bragg grating (FBG) sensors. The rapid tuning of the laser's wavelength is critical for achieving high measurement rates. However, the high tuning rate is demanding and requires careful characterization. We present a method for this and show, to our knowledge for the first time, data on the rapid tuning through the whole spectrum of this type of laser diode. We propose a modified centroid algorithm that can cope with nonequidistantly sampled spectra caused by the laser's functional principle. Finally, we demonstrate the dynamic performance of the new measurement system in an application: An FBG-based acceleration sensor is demodulated at a 5-kHz sample rate during a vibrational test showing the potential of the approach.

JCMS: Journal of Common Market StudiesVolume 48, Issue 2 p. 451-452 Constitutionalizing the European Union – By T. Christiansen and C. Reh LARS HOFFMANN, LARS HOFFMANN Tilburg UniversitySearch for more papers by this author LARS HOFFMANN, LARS HOFFMANN Tilburg UniversitySearch for more papers by this author First published: 01 February 2010 https://doi.org/10.1111/j.1468-5965.2009.02059_7.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume48, Issue2March 2010Pages 451-452 RelatedInformation

The aim of this study was to evaluate a novel third‐generation enzyme‐linked immunosorbent assay (ELISA) for the high‐sensitivity detection of autoantibodies to proteinase‐3 (PR3) in patients with Wegener's granulomatosis (WG). First‐ and second‐generation ELISA for the detection of antineutrophil cytoplasmic antibodies (ANCA) frequently demonstrate insufficient sensitivity due to inadequate presentation of autoantigenic epitopes. Human PR3 was immobilized on the solid phase of ELISA plates by anchoring technique. Anti‐PR3 reactivity was measured in 34 C‐ANCA positive patients with WG, 11 MPO‐ANCA–positive patients with other autoimmune vasculitides, 65 patients with systemic lupus erythematosus (SLE), and 137 healthy blood donors. Thirty‐three of 34 patients with WG (97.1%) showed positive anti‐PR3 IgG antibody reactivity. None of 11 MPO‐ANCA positive vasculitis patients, none of 137 blood donors, and 3 of 65 SLE patients expressed elevated IgG reactivity to PR3 (specificity: 98.4%). Comparison with another third‐generation ELISA did not reveal different qualitative results. However, there was no significant correlation between quantitative results of both assays. Receiver operating characteristic (ROC) curve analysis revealed a significantly better assay performance compared with first (direct)‐ and second (capture)‐generation assays ( P = 0.011 and P = 0.001, respectively). Third‐generation (anchor) anti‐PR3 ELISA exhibit significantly higher sensitivity than previous generation assays. Anchoring of PR3 renders the granulocyte protein more autoantigenic compared with direct or capture immobilization.

In late June the German Constitutional Court ruled on the compatibility of the Lisbon Treaty as well as the German accompanying laws (that ratified the Treaty) with the German Basic Law. Although the Court ruled that the Treaty was compatible with the Basic Law, it requested changes to the accompanying laws. The Court specifically refers to shortcomings in the areas of parliamentary accountability and democracy. This Commentary critically analysis the judgement and argues that the Court's ruling could start a new phase of national judicial activism that might threaten the legal and political integration process.

Embedded fiber Bragg gratings can be subjected to arbitrary states of strain including shear strain. Such perturbations can cause coupling between polarization modes. Coupled-mode theory in Bragg gratings so far neglected this effect and only considered forward-backward coupling. Polarization mode coupling within a Bragg grating leads to interdependencies between Bragg reflection peaks which have so far been unaddressed.We formulate a full strain tensor treatment of fiber Bragg gratings, considering the coupling of the polarization modes within the grating. We give an approximation for the coupling coefficients affecting the polarization mode coupling and numerically solve the coupled-mode equations for representative states of strain. We show in which way shear strain affects the optical response of a grating and demonstrate how the fiber's beat length influences this characteristic.

Robotic control and force-feedback applications require multi-axial force and torque sensing. One possible implementation of future sensors is seen in fiber optic force torque sensors, since the signal demodulation may be located in some distance to the actual sensor and they also do not have to include any magnetic material. This article presents a fiber Bragg grating-based force and torque sensor with six degrees of freedom. The general setup resembles a Stewart platform. Its connecting beams are formed by the fiber used to measure the deformation of the transducer. The element creating stiffness may be of arbitrary form. We demonstrate how the sensor is realized and show results of all six force and torque measurements. We present a theoretical model of the sensor. The results in this work demonstrate the feasibility of a fiber-optic force-torque sensor.

Modern telecommunication satellites can benefit from the features of fiber optic sensing wrt to mass savings, improved performance and lower costs. Within the course of a technology study, launched by the European Space Agency, a fiber optic sensing system has been designed and is to be tested on representative mockups of satellite sectors and environment.