Thermal Deposition of Intact Tetrairon(III) Single‐Molecule Magnets in High‐Vacuum Conditions

A tetrairon(III) single‐molecule magnet is deposited using a thermal evaporation technique in high vacuum. The chemical integrity is demonstrated by time‐of‐flight secondary ion mass spectrometry on a film deposited on Al foil, while superconducting quantum interference device magnetometry and alternating current susceptometry of a film deposited on a kapton substrate show magnetic properties identical to the pristine powder. High‐frequency electron paramagnetic resonance spectra confirm the characteristic behavior for a system with S = 5 and a large Ising‐type magnetic anisotropy. All these results indicate that the molecules are not damaged during the deposition procedure keeping intact the single‐molecule magnet behavior.     

Structural and electrochemical study of the reaction of lithium with silicon nanowires

The structural transformations of silicon nanowires when cycled against lithium were evaluated using electrochemical potential spectroscopy and galvanostatic cycling. During the charge, the nanowires alloy with lithium to form an amorphous Li_xSi compound. At potentials <50 mV, a structural transformation occurs. In studies on micron-sized particles previously reported in the literature, this transformation is a crystallization to a metastable Li₁₅Si₄ phase. X-ray diffraction measurements on the Si nanowires, however, show that they are amorphous, suggesting that a different amorphous phase (Li_ySi) is formed. Lithium is removed from this phase in the discharge to form amorphous silicon. We have found that limiting the voltage in the charge to 70 mV results in improved efficiency and cyclability compared to charging to 10 mV. This improvement is due to the suppression of the transformation at low potentials, which alloys for reversible cycling of amorphous silicon nanowires.     

P300-based BCI mouse with genetically-optimized analogue control.

In this paper we propose a brain-computer interface (BCI) mouse based on P300 waves in electroencephalogram (EEG) signals. The system is analogue in that at no point a binary decision is made as to whether or not a P300 was actually produced in response to the stimuli. Instead, the 2-D motion of the pointer on the screen, using a novel BCI paradigm, is controlled by directly combining the amplitudes of the output produced by a filter in the presence of different stimuli. This filter and the features to be combined within it are optimised by an evolutionary algorithm.     

A solar hydrogen hybrid system with activated carbon storage

A solar hydrogen hybrid system has been developed to convert, store and use energy from renewable energy sources. The theoretical model has been implemented in a dynamic model-based software environment and applied to real data. A photovoltaic sub-system drives a residential load and, if a surplus of energy is available, an electrolyzer to produce hydrogen which is stored in a cluster of nitrogen-cooled tanks filled with activated carbons; when needed, hydrogen is used in a fuel cell to supply power to the load. Hydrogen storage is achieved through physisorption at low temperature and low pressures. Physisorption storage provides safer operations along with good gravimetric and volumetric capacities at costs comparable to or smaller than compression or liquefaction storage.     

Characterizing the pollution produced by an industrial area: chemometric methods applied to the Lagoon of Venice

The industrial area of Porto Marghera discharges every year about 1.85 10(9) m(3) of waste waters in the Lagoon of Venice through its 142 discharge points, 17 of them being constantly active. The Anti-Pollution Department of Magistrato alle Acque, the Venice Water Authority, has been controlling these discharges for many years. The huge database built up during the last years could help the authorities in making choices regarding the water quality of the Venetian environment. The application of chemometric methods to the dataset obtained from chemical analyses of industrial waste water samples (almost 250, for each of them up to 57 chemical variables having been measured) is useful to answer fundamental questions related to the pollution generated by the industrial area: i) which are the main differences among the individual discharge points? ii) is there a temporal trend in global and punctual pollution? iii) which is the discharge point having the strongest relative impact on the waters? The results of the present work allow to 1) identify two different groups of discharge points, discriminated by the level of contamination and by the presence of different contaminants; 2) detect a relevant temporal trend in one of the main outfalls (the industrial and civil waste treatment plant); 3) set up a multivariate strategy to "measure" the relative modification induced on receiving lagoon waters by a single discharge. The application of such a "3-STEP multivariate analysis" to the present and future data of water quality could represent a relevant tool for monitoring industrial activities, providing at the same time a support in management decision processes.     

Dynamic output feedback linearization and global stabilization

We present a class of single-input single-output nonlinear systems which are globally transformable by a dynamic output feedback control and a time-varying state space transformation into a linear, observable and minimum phase system. We then show how those systems can be globally stabilized by a dynamic output feedback nonlinear control and how global output tracking can be achieved as well.     

Dopant Distributions in Rare-Earth-Doped Alumina

The distribution of yttrium and lanthanum dopants has been mapped in yttrium- and lanthanum-doped polycrystalline aluminas using imaging secondary-ion mass spectrometry (imaging-SIMS). Both dopants segregate to grain boundaries and pore surfaces. On average, yttrium occupies 7.1%–9.0% of the available grain-boundary cation sites, whereas lanthanum occupies only 2.0%–5.2%. In 1000-ppm-yttrium-doped alumina, an abundance of yttrium aluminum garnet precipitates also is observed. Implications of these observations to the creep behavior of alumina are discussed. The similarity in the segregation behavior of yttrium and lanthanum highlights the potential of lanthanum-doped alumina for improved creep properties.