Smart photochromic gratings with switchable wettability realized by green-light interferometry

We demonstrate the enhancement of the wetting properties of smart photochromic surfaces by a specifically developed, gentle interferometric patterning employing green light. We realized photochromic gratings with 2.5–10.0μm period by a blend consisting of a green-curable matrix and spiropyran molecules. The structured surfaces exhibit photocontrolled and reversible wettability, and enhanced hydrophilicity with respect to the native substrates. The dynamics of liquid spreading onto the gratings was also investigated, and the wetting behavior analyzed according to Wenzel's [Ind. Eng. Chem. 28, 988 (1936)] model for rough surfaces. These results indicate switchable gratings as promising functional components for microfluidics and modulation, and green-light interferometry as a reliable lithographic method for patterning organics without degradation or photochemical reactions

In vitro cadmium toxicity and its modulation by sulphur amino acids

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Frequency Assignment in Mobile and Radio Networks

. We deal with the problem of frequency assignment in mobile and general radio networks, where the signal interferences are modeled using an interference graph G. Our approach uses graph theoretic and optimization techniques. We first study on-line algorithms for frequency assignment in mobile networks. We prove that the greedy algorithm is \Delta-competitive, where \Delta is the maximum degree of G. We next employ the "classify and randomly select" paradigm to give a 5-competitive randomized algorithm for the case of planar interference graphs. We also show how the problem of on-line frequency assignment in mobile networks with multiple available frequency channels reduces to the problem of on-line frequency assignment in mobile networks with a single channel. We continue to study radio coloring and radio labeling as combinatorial models for frequency assignment in general radio networks. In both problems, the objective is to minimize the maximum frequency channel used, w..

On the Existence of Optimal Taxes for Network Congestion Games with Heterogeneous Users ⋆

Abstract. We consider network congestion games in which a finite number of non-cooperative users select paths. The aim is to mitigate the inefficiency caused by the selfish users by introducing taxes on the network edges. A tax vector is strongly (weakly)-optimal if all (at least one of) the equilibria in the resulting game minimize(s) the total latency. The issue of designing optimal tax vectors for selfish routing games has been studied extensively in the literature. We study for the first time taxation for networks with atomic users which have unsplittable traffic demands and are heterogeneous, i.e., have different sensitivities to taxes. On the positive side, we show the existence of weakly-optimal taxes for single-source network games. On the negative side, we show that the cases of homogeneous and heterogeneous users differ sharply as far as the existence of strongly-optimal taxes is concerned: there are parallellink games with linear latencies and heterogeneous users that do not admit strongly-optimal taxes.

Third-harmonic generation and multi-photon excitation fluorescence imaging microscopy techniques for online art conservation diagnosis

We present an appropriate methodology and results for using thirdharmonic generation (THG) modality for nondestructive high resolution imaging measurements of varnished structures in model painted artifacts. Detection takes place in the reflection mode, demonstrating the ability of the technique to be applied to the evaluation of original artworks. Furthermore, multi-photon excitation fluorescence images were obtained, providing complementary nformation related to the identification of the chemical composition of the artifactsThis work was supported by the UV Laser Facility operating at IESLFORTH under the European Commission ‘‘Improving Human Research Potential’’ program (RII3-CT-2003-506350) and by the Marie Curie Transfer of Knowledge project ‘‘NOLIMBA’’ (MTKD-CT-2005-029194)Postprint (published version

The Biocides Directive: Progress with the First Priority List

The first list of active biocidal substances is currently being evaluated and the progress is described in the following. In 2005 the third review regulation was adopted, and thus rapporteur member states are allocated for all existing active substances. The first list of substances was evaluated by the rapporteur member states and a first substance Annex I inclusion has taken place at technical level. The issues for discussion identified through the evaluation are described.JRC.I.3-Toxicology and chemical substance

Nonlinear imaging microscopy techniques as diagnostic tools for art conservation studies

The present results of the implementation of three-photon excitation fluorescence (3PEF) and third harmonicgeneration imaging measurements for the precise and nondestructive detection of natural and synthetic var-nish layers, which are used for the surface protection of painted artifacts. For this purpose, we employ as anexcitation source a compact femtosecond laser operating at1028 nmThe authors thank the UV Laser Facility operatingat Institute of Electronic Structure and Laser-Foundation of Research and Technology-Hellas(IESL-FORTH) under the European Commission“Improving Human Research Potential” program(RII3-CT-2003-506350) and the Marie Curie Transferof Knowledge project “Non Linear Imaging at Micro-scopic Level for Biological Applications (NOLIMBA)”(MTKD-CT-2005-029194)Postprint (published version

Micromachining of silicon carbide using femtosecond lasers

We have demonstrated micromachining of bulk 3C silicon carbide (3C- SiC) wafers by employing 1028nm wavelength femtosecond laser pulses of energy less than 10 nJ directly from a femtosecond laser oscillator, thus eliminating the need for an amplified system and increasing the micromachining speed by more than four orders of magnitude