Vibrational analysis of d-PCL(530)/siloxane-based hybrid electrolytes doped with two lithium salts

The present study has been focused on environmentally friendly sol–gel-derived electrolytes based on a di-urethane cross-linked d-PCL(530)/siloxane network [where d represents di, PCL identifies the poly(ε-caprolactone) biopolymer, and 530 is the average molecular weight in grams per mole] doped with a wide range of concentration of lithium perchlorate and lithium bis(trifluoromethanesulfonyl)imide. Fourier Transform Infrared and Raman spectroscopies have been applied to evaluate the extent of ionic association. Characteristic bands of the PCL(530) segments, of the urethane cross-links, and of the anions have been examined to gain insight into the cation/biopolymer, cation/anion, and cation/cross-link interactions. In both electrolyte systems, “free” ions and contact ions have been identified. The addition of salt modifies the hydrogen-bonded array of the host matrix, causing the destruction/formation of the urethane/urethane aggregates.     

Analysis of the gate current as a suitable indicator for FET degradation under nonlinear dynamic regime

Electron device degradation, although not directly accounted for, represents a key issue in microwave circuit design. This is especially true when the particular applications involved (e.g., satellite, military, consumer) do not allow or strongly discourage any kind of maintenance. As a matter of fact, in order to account for device degradation in circuit design, a suitable electron device model is needed which is able to predict the performance degradation as a function of the actual electrical regime involved in the device operation. Such a kind of model is not available in literature. In this paper, quantitative results are provided for device degradation indicators which correlate DC and RF stress experiments. These results can be considered an important step toward the definition of a nonlinear model accounting for device degradation.     

Making a mesh router/gateway from a smartphone: Is that a practical solution?

This paper aims at answering the question whether it is practical to build a mesh-phone or not. A mesh-phone is a smartphone acting as a mesh router, i.e. either actively participating in the process of packet forwarding towards a mesh gateway, or acting itself as a gateway toward the Internet. Technical aspects of the mesh-phone implementation, such as design constraints and implementation details, are addressed. The technical feasibility is validated by describing the implementation of a prototype of the mesh-enabled phone over the Openmoko^TM open platform. Besides technical feasibility also convenience of the addressed solution is analyzed in terms of the consumed power, and some “energy-saving” related enhancements are suggested to be applied to future user’s devices.     

Unexpected reactivity of trifluoromethylated olefins with indole: a mechanistic investigation

Several trifluoromethylated compounds were reacted with indole sodium salt, leading to monofluorinated compounds. The unexpected products formation was rationalized by DFT calculations.     

Electronic structure of IPR and non-IPR endohedral metallofullerenes: Connecting orbital and topological rules

The electronic structure of endohedral metallofullerenes is rationalized by connecting the apparently independent orbital and topological rules that explain the stability of this family of fullerenes. The separation of the 12 pentagons of the fullerene, which is maximized in order to minimize the Coulomb repulsion, is found to be correlated with the orbital energies of the cage that accepts the electron transfer from the internal cluster. An explanation for the absence of non-IPR cages in large-size EMFs is also provided.     

A Note on the Legendre Series Solution of the Biharmonic Equation for Cylindrical Problems

The solution of cylindrical problems is addressed. A series solution is considered of the biharmonic equation, in which the series terms of the stress function Φ are expressions based upon Legendre polynomials and logarithmically singular functions. An explicit form of a polynomial supplementing each logarithmically singular part of the series solution is obtained.     

A Lie symmetry approach for the solution of the inverse kinematics problem

In this paper, it is considered the inverse kinematics problem, which is faced from a differential point of view. In particular, it is shown that an asymptotic inverse kinematics can be interpreted as a Lie symmetry of the direct kinematics. A parameterization of all Lie symmetries of the direct kinematics is proposed, and the classical Newton and gradient method are obtained as particular cases.     

A topological phase transition between small-worlds and fractal scaling in urban railway transportation networks?

Fractal and small-worlds scaling laws are applied to study the growth of urban railway transportation networks using total length and total population as observational parameters. In spite of the variety of populations and urban structures, the variation of the total length of the railway network with the total population of conurbations follows similar patterns for large and middle metropolis. Diachronous analysis of data for urban transportation networks suggests that there is second-order phase transition from small-worlds behaviour to fractal scaling during their early stages of development.     

Water flows induced by microwave electric fields in microsystems

AC electric fields are of increasing importance for the generation of fluid flows in microsystems. We analyse numerically the use of AC electric fields at microwave frequencies for electro-thermal actuation of water in microdevices. Water is heated because of its significant dielectric loss at microwave frequencies. Buoyancy and dielectric forces actuate in the liquid bulk, and the relative importance between them is studied. The microwave liquid actuation can be used for pure water as well as for water saline solutions, such as bio-fluids. Therefore, it is of interest for the Lab-on-a-Chip technology.     

Gauss’ law of error revisited in the framework of Sharma-Taneja-Mittal information measure

We reformulate the Gauss’ law of error in presence of correlations which are taken into account by means of a deformed product arising in the framework of the Sharma-Taneja-Mittal measure. Having reviewed the main proprieties of the generalized product and its related algebra, we derive, according to the Maximum Likelihood Principle, a family of error distributions with an asymptotic power-law behavior.