Cyano-bridged coordination polymer nanoparticles with high nuclear relaxivity: toward new contrast agents for MRI

New water-soluble paramagnetic Gd-containing cyano-bridged metallic coordination polymer nanoparticles with a chitosan shell show high nuclear relaxivity in acidic water which is up to six times higher than that of the actually used Gd-chelates.     

Reproducibility experiments on measuring acoustical properties of rigid-frame porous media (round-robin tests)

This paper reports the results of reproducibility experiments on the interlaboratory characterization of the acoustical properties of three types of consolidated porous media: granulated porous rubber, reticulated foam, and fiberglass. The measurements are conducted in several independent laboratories in Europe and North America. The studied acoustical characteristics are the surface complex acoustic impedance at normal incidence and plane wave absorption coefficient which are determined using the standard impedance tube method. The paper provides detailed procedures related to sample preparation and installation and it discusses the dispersion in the acoustical material property observed between individual material samples and laboratories. The importance of the boundary conditions, homogeneity of the porous material structure, and stability of the adopted signal processing method are highlighted.     

Magnetically induced thermal rectification

We consider far from equilibrium heat transport in chaotic billiard chains with noninteracting charged particles in the presence of nonuniform transverse magnetic field. If half of the chain is placed in a strong magnetic field, or if the strength of the magnetic field has a large gradient along the chain, heat current is shown to be asymmetric with respect to exchange of the temperatures of the heat baths. Thermal rectification factor can be arbitrarily large for sufficiently small temperature of one of the baths.     

Compact fibre-based coherent anti-Stokes Raman scattering spectroscopy and interferometric coherent anti-Stokes Raman scattering from a single femtosecond fibre-laser oscillator

We demonstrate a new approach to CARS spectroscopy by efficiently synthesizing synchronized narrow-bandwidth (less than 10 cm⁻¹) pump and Stokes pulses (frequency difference continuously tunable upto ≈3000 cm⁻¹) based on spectral compression together with second harmonic generation (in periodically-poled nonlinear crystals) of femtosecond pulses emitted by a single compact Er-fibre oscillator. For a far better signal to non-resonant background contrast, interferometric CARS (I-CARS) is demonstrated and CARS signal enhancement upto three orders of magnitude is achieved by constructive interference with an auxiliary local oscillator at anti-Stokes field, also synthesized by spectral compression of pulses emitted from the same fibre oscillator.     

Spectral Theory of a Neumann–Poincaré-Type Operator and Analysis of Cloaking Due to Anomalous Localized Resonance

The aim of this paper is to give a mathematical justification of cloaking due to anomalous localized resonance (CALR). We consider the dielectric problem with a source term in a structure with a layer of plasmonic material. Using layer potentials and symmetrization techniques, we give a necessary and sufficient condition on the fixed source term for electromagnetic power dissipation to blow up as the loss parameter of the plasmonic material goes to zero. This condition is written in terms of the Newtonian potential of the source term. In the case of concentric disks, we make the condition even more explicit. Using the condition, we are able to show that for any source supported outside a critical radius, CALR does not take place, and for sources located inside the critical radius satisfying certain conditions, CALR does take place as the loss parameter goes to zero.     

Determination,aerobic biodegradation and environmental occurrence of aliphatic alcohol polyethoxylate sulfates (AES)

A new analytical method was developed for the routine specific determination of the anionic surfactant Alcohol polyEthoxylate Sulfate (AES) in environmental aqueous samples. An enrichment/fractionation of the target analytes in water samples was performed by solid-phase extraction (SPE) on graphitized carbon black (GCB) (recoveries: 90–103%), followed by hydrolysis/derivatization with fluorescent reagents and separation/detection by reversed-phase high performance liquid chromatography coupled with fluorescence (HPLC-FLD). The developed procedure was applied to the study of the aerobic biodegradation of AES under laboratory conditions and to a ten-month monitoring of AES, as well as of linear alkylbenzene sulfonates (LAS), nonylphenol polyethoxylates (NPE) and alcohol polyethoxylates (AE) surfactants, in the Po river (Northern Italy). The residual concentrations found in the river waters were compared and used for a preliminary estimation of the annual average loads of monitored surfactants in the Adriatic Sea.