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The originality of the present photocatalytic system consists in using luminous textiles for a double purpose: (i) supporting TiO2 photocatalysts and (ii) conveying UV-light all along the optical fibers and distributing it to the TiO2 particles deposited. Photocatalytic luminous textiles were tested in terms of stability and their photocatalytic activities were determined in the purification of water containing either formic acid or phenol. Luminous textiles were coated with TiO2 sols and or suspensions. The location of TiO2 was analysed by ESEM and EDX analysis and was shown to be uniform over the surface of optical fiber textiles, except for TiO2 powder coating, exhibiting titania present as clusters. A good adhesion and stability of the photocatalyst layer were found. The photocatalytic performances of the different TiO2 coatings, tested in the degradation of two model pollutants (formic acid and phenol), in a batch reactor indicated an optimum mass of TiO2 of about 2 mg/cm2. Degradation tests highlighted the higher activity of TiO2 powder coating in comparison with others coating tested, whatever the catalyst mass or pollutant tested. Photonic yields depend on the absorption properties of the coating. They range from 23 to 60% for formic acid degradation and from 6 to 8% for that of phenol, proving the efficiency of such luminous textile coating by TiO2. The performances observed indicate that luminous textiles are good candidates for supporting titania photocatalysts, thus avoiding tedious final filtrations when using suspensions

A newly designed thin-layer STM (TLSTM) technique is presented based on a microfabricated probe combining an electrolytic STM probe with an annular iridium oxide microelectrode operating as a potential-controlled generator or scavenger of H+. This TLSTM configuration can be used to combine in situ STM studies of electrode processes with the simultaneous investigation of H+ flux integrals associated with the electrode reaction. In this paper, the technique is applied to investigate the H+ exchange behaviour of electropolymerised polyaniline films and associated STM-relevant properties in 0.5 M NaClO4 + 10-2 M HClO4. For a polyaniline film kept in the intermediate (emeraldine) oxidation state at 0 mV versus MSE it is shown that its thickness increases due to H+ insertion if the pH is lowered from pH 2 to ca. 1.6, and that its conductivity decreases significantly if the pH is increased from 2 to ca. 12. In a second experiment, where the exchange of H+ at pH 2 is monitored during film oxidation and reduction within the potential range of both redox transfer steps, it is shown that significant exchange of H+ occurs only in the interval of the second (emeraldine/pernigraniline) redox transfer. © 2001 Elsevier Science Ltd. All rights reserved.

Diamond tips are attractive tools for nanoscience because of their hardness and, when doped chemical vapor deposited (CVD) diamond is used, their electrical conductivity. In this article, devices based on CVD diamond coated silicon tips and molded diamond pyramids are described. A new type of tip, with a controlled selectively deposited diamond coating, on its upper part only, is presented, which will be useful for integration with actuators, sensors, etc. Pyramidal diamond tips with cantilevers have been micromachined and characterized, with apex radii in the range 10 to 40 nm. Structuring the diamond layer by reactive ion etching resulted in a very well defined shape of the cantilever. From resonance frequency measurements, Young's modulus of the diamond cantilevers was found to be in agreement with reported values. Preliminary tests have shown the pyramidal tips to be suitable for atomic force microscopy.

Thick photoresist (about 40 m) was patterned and used as a protective layer for protruding structures (sharp, high aspect ratio atomic force microscope tips) in wet (buffered hydrofluoric acid) and dry (reactive ion etching) etching. The process and results of its use are discussed, and some applications are proposed.

Silicon bulk micro machining allows the batch fabrication of miniaturized xy-stages integrating a tip for atomic force sensing, via hole for optical detection and electrostatic comb actuators for lateral scanning. In this paper we present a device which integrates a large tip (about 50 /spl mu/m high) with high aspect ratio (1.7:1) on the central stage, improving thus significantly the access to the sample to be scanned. In spite of the mass increase due to the larger tip dimensions, measured resonance frequencies remain high enough (several kHz) to make the device insensitive to the environmental noise.

Self sharpening tips have been integrated on arrays of cantilevers provided with self exciting piezoelectric sensors (ZnO) by using monocrystalline silicon micromachining. Atomic force microscopy (AFM) images of grids with periods of 0.25 /spl mu/m, 1 /spl mu/m and 5 /spl mu/m and with height differences of 100 nm, 15 nm and 180 nm respectively have been achieved with single cantilevers.

The use of laser in arthroscopy is the result of historical developments, and its evolution follows the course common to most new technologies, with particular relevance to the concept of minimally invasive surgery. The gradual introduction of new laser beams such als neodymium, holmium, and erbium — the latter still at the experimental stage — has allowed the development of fiberoptics and made it possible to use these lasers in arthroscopy surgery.

A new technique for measuring CO(2) concentration in air samples, based on mass spectrometry, is described as an alternative to the common gas chromatographic method. Using a dual inlet isotope ratio mass spectrometer (IRMS), the ratio of the abundances of the m/z peaks 44 and 28 is determined. The precision of measurements (standard deviation

In-situ nanoscale probing of the solid-liquid interface, in particular by electrolytic STM and SFM, has gained considerable importance in electrochemistry and has given rise to novel nanoscale applications in electrochemical systems, including first attempts for electrochemical nanostructuring methods. In this report, selected examples are presented to illustrate the present state and future potential of nanoscience in electrochemistry.

Note: 231 Reference SAMLAB-ARTICLE-2000-015 Record created on 2009-05-12, modified on 2016-08-08

A high-resolution ice-core record of atmospheric CO2 concentration over the Holocene epoch shows that the global carbon cycle has not been in steady state during the past 11,000 years. Analysis of the CO2 concentration and carbon stable-isotope records, using a one-dimensional carbon-cycle model,uggests that changes in terrestrial biomass and sea surface temperature were largely responsible for the observed millennial-scale changes of atmospheric CO2 concentrations.

Note: 202 Reference SAMLAB-ARTICLE-1999-018doi:10.1002/(SICI)1096-9918(199905/06)27:5/6 3.0.CO;2-E Record created on 2009-05-12, modified on 2016-08-08