Controlling spin-spin network dynamics by repeated projective measurements

We show that coupled-spin network manipulations can be made highly effective by repeated projections of the evolving quantum states onto diagonal density-matrix states (populations). As opposed to the intricately crafted pulse trains that are often used to fine-tune a complex network's evolution, the strategy hereby presented derives from the "quantum Zeno effect" and provides a highly robust route to guide the evolution by destroying all unwanted correlations (coherences). We exploit these effects by showing that a relaxationlike behavior is endowed to polarization transfers occurring within a N-spin coupled network. Experimental implementations yield coupling constant determinations for complex spin-coupling topologies, as demonstrated within the field of liquid-state nuclear magnetic resonance.     

Domino reactions for the synthesis of various α-substituted nitro alkenes

Efficient one-pot methods for the synthesis of variously functionalised conjugated nitro alkenes have been reported. Despite the utility in different fields of these compounds, only a few multi-step syntheses have been reported in the literature, giving the target compounds in low overall yields. α-Nitro acrylates or cinnamates, α-nitro α,β-unsaturated ketones and, most importantly, aromatic and heteroaromatic (E)- 2-nitro allylic alcohols, compounds characterised by a well-known anticancer activity, were obtained in high yields and high diastereomeric purity by a domino condensation-dehydration process.     

Unmanned platform for long-range remote analysis of volatile compounds in air samples

This paper describes a long-range remotely controlled CE system built on an all-terrain vehicle. A four-stroke engine and a set of 12-V batteries were used to provide power to a series of subsystems that include drivers, communication, computers, and a capillary electrophoresis module. This dedicated instrument allows air sampling using a polypropylene porous tube, coupled to a flow system that transports the sample to the inlet of a fused-silica capillary. A hybrid approach was used for the construction of the analytical subsystem combining a conventional fused-silica capillary (used for separation) and a laser machined microfluidic block, made of PMMA. A solid-state cooling approach was also integrated in the CE module to enable controlling the temperature and therefore increasing the useful range of the robot. Although ultimately intended for detection of chemical warfare agents, the proposed system was used to analyze a series of volatile organic acids. As such, the system allowed the separation and detection of formic, acetic, and propionic acids with signal-to-noise ratios of 414, 150, and 115, respectively, after sampling by only 30 s and performing an electrokinetic injection during 2.0 s at 1.0 kV.     

Orbits of Lagrangian Subalgebras of the Double sl(2, R)

We describe the variety of Lagrangian subalgebras of the Drinfeld double for an arbitrary bialgebra structure on sl(2, R). We determine the irreducible components and the orbit structure under the natural action of the group SL(2, R)     

Extended Fuzzy C-Means and Genetic Algorithms to Optimize Power Flow Management in Hybrid Electric Vehicles

The need for personal transportation must be harmonized by considering the impact of so huge number of vehicles on the environment. The adoption of hybrid electric vehicles can provide a sensible improvement from an environmental viewpoint, but at the same time makes more difficult the definition and implementation of the overall powertrain control mechanism. In fact, powertrain control problems are known to be very complex due to conflicting requirements, and this difficulty augments in case of hybrid electric vehicles. Most of the features of the future hybrid electric vehicles are enabled by a new energy flow management unit designed to split the instantaneous power demand between the internal combustion engine and the electric motor, ensuring both an efficient power supply and reduced emissions. Classic approaches that rely on static thresholds, optimized on a fixed drive cycle, cannot face the high dynamicity and unpredictability of real-life drive conditions. The need to actually control a real vehicle stimulates the research of innovative methodologies for the real-time identification of the operating points of each energy source. This paper is framed into this context: after a brief discussion about a non-conventional formalization of the energy flows problem based on a multiobjective function, a knowledge-based control system for splitting the vehicle's power demand between the engine and motor is presented. The proposed approach exploits a fuzzy clustering criterion that combined with a genetic algorithm, permits to achieve better results, both in terms of a reduced computational effort and an improved efficiency of the control system over various driving cycles. To validate the proposed approach, simulation tests and comparisons with other energy management strategies are discussed.     

Synthesis of some 2,3-benzo-l-oxaoctems

The synthesis of some 8-hydroxy-2,3-benzo-l-oxaoctems is reported. The imide 7 , a potential β-lactamase inhibitor, was also synthesized.     

Thermoplastic elastomers: Structural and morphological aspects of ether–esteramide copolymers

Polyesteramide 6NT6–polytetramethylene ether glycol (PTMEG) copolymers, precipitated from dilute solution, have been studied by small-angle x-ray scattering (SAXS) and wide-angle x-ray scattering (WAXS) with variation of the PTMEG content. A comparison of the structural characteristics of these materials has been made with those of the 6NT6 homopolymer. Chain folding is assumed as the crystallization mechanism for the low-PTMEG-content copolymers, with possible inclusion of polyether segments within the 6NT6 crystal lattice. WAXS data support the view of a weakening of the 6NT6 crystalline packing in the equatorial planes as the reason for broadening of the diffraction peaks, for changes in their relative intensities, and for the increase in the equatorial interplanar distances in the high-PTMEG-content samples. The annealing behavior has also been investigated.     

AnL s-estimate for the gradient of solutions of some nonlinear unilateral problems

Sunto In questo lavoro si danno stime L^s. s>p, per il gradiente di soluzioni di problemi unilaterali (sia a crescenza controllata che naturale), disequazioni variazionali e minimizzazione di funzionali.     

Inverse Jacobi multipliers

Inverse Jacobi multipliers are a natural generalization of inverse integrating factors ton-dimensional dynamical systems. In this paper, the corresponding theory is developed from its beginning in the formal methods of integration of ordinary differential equations and the “last multiplier” of K. G. Jacobi. We explore to what extent the nice properties of the vanishing set of inverse integrating factors are preserved in then -dimensional case. In particular, vanishing on limit cycles (in restricted sense) of an inverse Jacobi multiplier is proved by resorting to integral invariants. Extensions of known constructions of inverse integrating factors by means of power series, local Lie Groups and algebraic solutions are provided for inverse Jacobi multipliers as well as a suitable generalization of the concept to systems with discontinuous right-hand side.