Diagnosis of Active Systems by Automata-Based Reasoning Techniques

This paper presents a method for the diagnosis of active systems, these being a class of distributed asynchronous discrete-event systems, such as digital networks, communication networks, and power transmission protection systems. Formally, an active system is viewed as a network of communicating automata, where each automaton describes the behavior of a system component. The diagnostic method encompasses four steps, namely system modeling, reconstruction planning, behavior reconstruction, and diagnosis generation. System modeling formally defines the structure and behavior of system components, as well as the topology of the active system. Based on optimization criteria, reconstruction planning breaks down the problem of system behavior reconstruction into a hierarchical decomposition. Behavior reconstruction yields an intensional representation of all the dynamic behaviors that are consistent with the available system observation. Eventually, diagnosis generation extracts diagnostic information from the reconstructed behaviors. The diagnostic method is applied to a case study in the power transmission network domain. Unlike other proposals, our approach both deals with asynchronous events and does not require any global diagnoser to be built off-line. The method, which is substantiated by an ongoing implementation, is scalable, incremental, and amenable to parallelism, so that real size problems can be handled.     

Synthesis of 8-hydroxyquinoline functionalised DO3A ligand and Eu(III) and Er(III) complexes: Luminescence properties

The synthesis of a new DO3A-based macrocyclic ligand bearing a 8-hydroxyquinoline residue together with the preparation of its Eu³⁺ and Er³⁺ neutral complexes are described. In a previous report [F. Rizzo, A. Papagni, F. Meinardi, R. Tubino, M. Ottonelli, G.F. Musso, G. Dellepiane, Synth. Met. 147 (2004) 143], we have shown that lanthanide complexes display very high stability combined with a good luminescence in aqueous solution under UV radiation, which indicate an energy transfer process from the excited 8-hydroxyquinoline moiety to the metal. In this work, we correlate the ability to transfer the energy from the sensitizer to lanthanide ion with pH behaviour of the antenna. Furthermore, the variation of pH in Eu³⁺ complex supports the hypothesis of presence of charge-transfer transitions. The good solubility and sensitized emission in different solvents (organic and water) are very important aspects for their technologic applications as luminescent probes or NIR-emitting devices.     

Evaluation of the Feasibility of Irrigation Storage in a Flood Detention Pond in an Agricultural Catchment in Northern Italy

During recent years, the international attention paid to rational use and saving of water has increased, partly because of frequent water shortages occurring also in countries not usually involved in these problems, and partly as a consequence of rising conflicts on water allocation. Hence it is important to find new surface-water volumes satisfying agricultural water demand, as well as new ways and areas to store them. The simulation model presented by the paper enables evaluation, in a phase of design feasibility analysis, of whether a flood detention pond can be adapted to act as water storage during irrigation periods in order to reduce agricultural water shortages; it simulates detention pond response to floods and droughts under different hydraulic conditions and reservoir management rules. The first policy goal of the model is to maintain the stored volume within the maximum admissible for flood safety. The second goal is to maintain at the same time a minimum flow in the river and to satisfy irrigation water demand. The model, implemented in a purpose-made simulation software, was applied to an Italian river in the Emilia Romagna region: the results demonstrate that the use of a flood detention pond as an irrigation reservoir is not only possible, if it complies with the operating rules that emerge from this study, but also it brings tangible benefits in reducing agricultural water deficit.     

Towards single atom analysis of biological structures.

Mapping single atoms in biological structures is now becoming within the reach of analytical electron microscopy. Electron energy-loss spectroscopy (EELS) in the field-emission scanning transmission electron microscope (STEM) provides a particularly high sensitivity for detecting the biologically important element, phosphorus. Imaging can be performed at low dose with dark-field STEM prior to analysis at high dose, so that structures of macromolecular assemblies can be correlated with the numbers of specific atoms that they contain. Measurements confirm theoretical predictions that single atom detection requires a nanometer-sized probe. Although phosphorus atoms may have moved several nanometers from their original positions by beam-induced structural degradation at the high required dose of approximately 10(9) e/nm2, damaged molecules are nevertheless stable enough to be analyzed at 1 or 2 nm resolution. Such analyses can only be achieved by means of spectrum-imaging with correction for specimen drift. Optimal strategies for mapping small numbers of phosphorus atoms have been investigated using well-characterized specimens of DNA plasmids and tobacco mosaic virus.     

A 2.7-V CMOS single-chip baseband processor for CT2/CT2+ cordlesstelephones

A low-voltage, low-power CMOS single-chip baseband processor for CT2 and CT2+ cordless telephones is presented. The chip integrates a complete voiceband codec, a tone generator, a G721 adaptive differential pulse code modulation coder/decoder, a burst-mode logic controller for CT2/CT2+ framings, and an I/Q baseband signal generator. The only external components are made of two quartz crystals. The chip is interfaced with standard microcontrollers through a parallel interface. With a 2.7 V minimum supply, it consumes normal and standby powers of 35 mW and 25 μW, respectively. Maximum supply is 5.5 V, and temperature range is from -40 to 70°C. Chip area (including scribe line) is 55.5 mm² in a 0.8 μm N-well double-metal single-poly CMOS process with implanted capacitors     

Two-point constraint approximation in structural optimization

The use of constraint approximations is recognized as a primary means of achieving computational efficiency in structural optimization. Existing approximation methods are based upon the value of the constraint function and its derivatives at a single point. The present paper explores the use of approximations based upon the value of the constraint and its derivative at two points. Several candidate approximations are suggested and tested for randomly generated rational constraint functions. Several of the approximations prove to be superior to the single-point approximations.     

New Active Tools for Supporting Narrative Structures

Constructing stories is a type of playing that involves mobilizing the storyteller’s imagination and finding original ways to convey narrative intentions. When a child invents a story, there is a natural interaction with the local environment and the use of various means of expression. We adopted a user-centered approach to design POGO, a playful environment which utilizes the child’s physical environment and sensory modalities. Pogo is a system of active tools that enable children to create stories by connecting physical and virtual environments. By providing children with the possibility of capturing and manipulating images and various media, and combining them in sequential form, Pogo triggered new strategies in the construction of narrative logic, time and space, in the construction of the episodes and in the visual narration. Correspondence to: Fran?oise Decortis, Psychology and Education Sciences Department, University of Liege, 4000 Liege, Belgium. Email:francoise.decortis@ulg.ac.be     

Kinetic study of 1,5-cyclooctadiene hydro-isomerization on Pd/pumice catalysts

A new route for obtaining 1,4-cyclooctadiene by catalytic isomerization of 1,5-cyclooctadiene at low temperature in presence of H₂ in a three-phase reactor is presented. Wei, Prater and Silvestri methods are used for the kinetic studies. A comparison of the activity-selectivity patterns of the Pd/pumice catalysts with Pd on silica and Pt and Pd–Pt on pumice catalysts is performed. Although Pt catalysts are not active in the hydro-isomerization of 1,5-cyclooctadiene, the presence of small amount of Pt in Pd/pumice catalysts increases the yield to 1,4-cyclooctadiene. Besides the catalyst characteristics, temperature and H₂ pressure influence the production of 1,4-cyclooctadiene. A mechanism of the process is proposed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Improvement of Drug Therapy by Covalent PEG Conjugation: An Overview From a Research Laboratory

In the last two decades, efforts focused in the field of drug delivery have made it possible to reach important goals, especially with proteins and peptides. The story of the evolution of this matter is vast and it is difficult to summarize its various aspects in a single review. On the other hand, it could be really interesting to look at the inside story of a typical academic research lab that has dedicated almost all its resources to drug delivery. In our case, an initial interest in the issue of protein conformation stability soon paved the way for a new area of study: the modification of proteins with synthetic polymers. We have seen this technique transformed from a crude and inhomogeneous procedure into a well-recognized and successful approach. This great advance has been possible thanks to the development of dedicated chemical coupling methods and to the better understanding of the behavior of polymers in vivo. In particular, among the several polymers investigated, PEG has became the best polymer for protein modification. Exploiting the unique properties of this polymer, we have conducted several investigations in the field of protein PEGylation and then transferred the acquired know-how to the development of conjugates with low molecular weight drug. This last aspect still presents several unmet needs that are awaiting proper solutions.     

An effective multipurpose building block for 3D electropolymerisation: 2,2′-Bis(2,2′-bithiophene-5-yl)-3,3′-bithianaphthene

Novel thiophene-based oligomer, 2,2′-bis(2,2′-bithiophene-5-yl)-3,3′-bithianaphthene (TX), was designed and synthesized, and its electrochemical and spectral properties characterised. TX was readily polymerised electrochemically to form well organized conducting homopolymer films on various solid electrode substrates. Moreover, it was successfully used for deposition by electropolymerisation of electrochemically active thin films of co-polymers with three different monomers of functionalised bis(2,2′-bithienyl)methane derivatives. It appeared that TX was an effective crosslinker and 3D promoter in these electropolymerisations involving co-monomers intrinsically showing limited aptitude for the electropolymerisation or forming polymer films of low conductivity. This attractive TX ability stems from combination of its (i) high conjugation efficiency in each of the two planar moieties, (ii) intrinsic 3D structure on account of the presence of the central node, and (iii) intrinsic regioselectivity in electropolymerisation on account of the positions of the two available free α-thiophene sites.