Inertial-magnetic sensors for assessing spatial cognition in infants

This letter describes a novel approach to the assessment of spatial cognition in children. In particular, we present a wireless instrumented toy embedding magneto-inertial sensors for orientation tracking, specifically developed to assess the ability to insert objects into holes. To be used in naturalistic environments (e.g., day cares), we also describe an in-field calibration procedure based on a sequence of manual rotations, not relying on accurate motions or sophisticated equipment. The final accuracy of the proposed system, after the mentioned calibration procedure, is derived by direct comparison with a gold-standard motion tracking device. In particular, both systems are subjected to a sequence of ten single-axis rotations (approximately 90°, back and forth), about three different axes. The rms of the angular error between the two measurements (gold-standard versus proposed systems) was evaluated for each trial. In particular, the average rms error is under 2°. This study indicates that a technological approach to ecological assessment of spatial cognition in infants is indeed feasible. As a consequence, prevention through screening of large number of infants is at reach.     

RF-MEMS switch design optimization for long-term reliability

This contribution presents an optimization strategy for the mechanical and geometrical characteristics of clamped–clamped dielectric-less RF-MEMS switches in order to enhance their reliability performances both in terms of switch properties control and long-term actuation behavior. The modifications mainly affect the switch membrane, which is made more robust, and the stopping pillar dimensions, while the switch dimensions are practically unaffected. In the case of the proposed ohmic switch, also the mobile contact region was redesigned in order to increase the contact force. Experimental measurements have demonstrated that the optimized version of the capacitive switch investigated shows an improved resistance to high bias voltages (up to 90 V), while the optimized ohmic switch shows a lower, more stable and more reproducible contact resistance. Long-term actuation measurements are analyzed in detail, proposing a model to evaluate the switch lifetime, which was found of the order of few years in the more conservative estimate in the case of capacitive switches. The lifetime estimates are less precise in the case of ohmic switches, mainly because the contact instability sums up with the charging contribution. In spite of the improved switch general properties, lifetime is however not increased with optimization. The most likely explanation is that the optimization strategy was aimed at reducing charge injection and charge non-uniformity, but other effects can be important in lifetime determination.     

Improving Head Movement Tolerance of Cross-Ratio Based Eye Trackers

When first introduced, the cross-ratio (CR) based remote eye tracking method offered many attractive features for natural human gaze-based interaction, such as simple camera setup, no user calibration, and invariance to head motion. However, due to many simplification assumptions, current CR-based methods are still sensitive to head movements. In this paper, we revisit the CR-based method and introduce two new extensions to improve the robustness of the method to head motion. The first method dynamically compensates for scale changes in the corneal reflection pattern, and the second method estimates true coplanar eye features so that the cross-ratio can be applied. We present real-time implementations of both systems, and compare the performance of these new methods using simulations and user experiments. Our results show a significant improvement in robustness to head motion and, for the user experiments in particular, an average reduction of up to 40 % in gaze estimation error was observed.     

First plasma operation of the enhanced JET vertical stabilisation system

A project dedicated to the enhancement of the JET vertical stabilization system was launched in 2006, including an upgrade of the Power Supply of the Radial Field Amplifier, of hardware and software of the vertical stabilization control system. The main aim was to double the JET capability in stabilising high current plasmas when subject to perturbations, in particular large Edge Localised Modes. We present here the results of first plasma operation with the new Enhanced Radial Field Amplifier and its data acquisition and control system, focussing on the benefits of an approach based on phased commissioning, modelling and offline algorithm validation.     

Synthesis and Structure−Activity Relationships of Imidazopyridine/Pyrimidine- and Furopyridine-Based Anti-infective Agents against Trypanosomiases

Neglected tropical diseases remain among the most critical public health concerns in Africa and South America. The drug treatments for these diseases are limited, which invariably leads to fatal cases. Hence, there is an urgent need for new antitrypanosomal drugs. To address this issue, a large number of diverse heterocyclic compounds were prepared. Straightforward synthetic approaches tolerated pre-functionalized structures, giving rise to a structurally diverse set of analogs. We report on a set of 57 heterocyclic compounds with selective activity potential against kinetoplastid parasites. In general, 29 and 19 compounds of the total set could be defined as active against Trypanosoma cruzi and T. brucei brucei, respectively (antitrypanosomal activities <10 μM). The present work discusses the structure−activity relationships of new fused-ring scaffolds based on imidazopyridine/pyrimidine and furopyridine cores. This library of compounds shows significant potential for anti-trypanosomiases drug discovery.     

Correlation between microstructure and corrosion behavior in an AISI 316L steel pipeline exposed for 100,700 h at 640°C in a petrochemical plant

The microstructure and electrochemical properties of 316L stainless steel were investigated after two conditions: aged at 640°C for 100,700 h and solution annealed at 1050°C for 2 h. While the aged samples were obtained from a pipe of a petrochemical reactor plant that was in service, the solution annealing was carried out in a conventional laboratory furnace. After aging, the precipitates present in decreasing order of quantity were sigma, Laves phase, and M₂₃C₆. After solution annealing, the microstructure was full austenitic. These results were in agreement with equilibria phase simulation with Thermo-Calc software. Intergranular corrosion susceptibility, evaluated by means of the single loop electrochemical potentiokinetic reactivation technique and Practice A of ASTM 262, indicated a preponderant role for the sigma precipitate. The pitting potential (E_pit) was evaluated through potentiodynamic polarization curves in 0.6 M NaCl and electrochemical impedance spectroscopy was performed at the corrosion potential to complement the information about the corrosion resistance.