569 research outputs found

    Optically activated ZnO/Sio2/Si cantilever beams

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    The photomechanical effect induced by periodically varying sub-bandgap illumination in thin ZnO films deposited on oxidized Si has been demonstrated for the first time. The efficiency of this effect is at least one order of magnitude higher as compared to the photothermal activation of Si. Thus it can be considered as a powerful optical drive for resonant sensors. A phenomenological model of the mechanisms involved in the process is proposed. The optomechanical effect can also be used as a complementary method in determination of the surface state parameters of ZnO films

    Investigations into Earthworm Control on Airports

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    Earthworms, though generally considered beneficial for soil conditioning, can become a hazard at airports. When found in large numbers on runways or taxiways after heavy rainfall, they create slippery conditions for aircraft rolling over them. Additionally, earthworms attract birds, especially gulls, thereby increasing the risk of bird strikes to aircraft that are landing or taking off. For example, during a 35-minute period on 3 September 2004 at Calgary International Airport (YYC), a B737 of Westjet and an A319 of Air Canada aborted takeoffs after multiple strikes with gulls attracted to the runways to feed on earthworms. The B737 had strikes and damage to both engines and the A319 had damage (apparently an uncontained failure) to one engine. In the Netherlands, they build concrete moats to keep worms off of runways. There are no pesticides registered for earthworm control. Consequently any application of a pesticide to kill worms would be illegal. Researchers in England, Oregon, and Washington found that incorporating abrasive material into soil reduced the number of worms coming to the surface. We are conducting trials at the USDA\u27s National Wildlife Research Center Ohio Field Station to develop simple procedures to reduce earthworm numbers on runways and taxiways. In lab trials, night crawlers (Lumbricus terrestris) have been initially repelled from areas containing phosphate fertilizer, high nitrate fertilizer or a mustard byproduct. Ground mustard mixed with diatomaceous earth also shows promise in reducing the number of earthworms in treated plots. Additionally, when placed on recycled coal slag, the worms have not burrowed into the material but tried to leave the test site. We anticipate field trials to investigate an integrated approach involving products that present both chemical and physical irritants. If a successful combination of products is determined, the number of earthworms crawling onto taxiways and runways could be significantly reduced

    Do state and trait measures measure states and traits? The case of community-dwelling caregivers of older adults

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    Spielberger’s state and trait anxiety and anger scales are widely used and documented, but there is little or no direct evidence that they actually measure their respective state and trait aspects as was intended. We conducted latent state-trait analyses on data collected from 310 community-dwelling caregivers of older adult care recipients and found that (a) both state and trait scales reflected a mixture of state and trait aspects of their latent constructs, (b) state scales reflected more state-like variance than did corresponding trait scales, but (c) both state and trait scales were dominated by stable trait-like variance. Follow-up bivariate latent state-trait analyses indicated that correlations between trait components of anger and anxiety correlated more strongly with trait components of caregiver–care recipient mutually communal behavior and care recipient problem behavior than did state–state component correlations. Implications for the measurement of state and trait components of psychological constructs are discussed

    Functional behaviour of TiO2films doped with noble metals

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    To evaluate the effects of different concentrations of noble metal in a TiO2 matrix, different films of both Ag:TiO2 and Au:TiO2 systems were prepared. Mechanical and tribological characterization was carried out to evaluate the coatings response as a function of the noble metals composition and (micro)structure of the films. The overall set of results indicates that the amorphous films reveal better results than the crystalline ones. For the amorphous samples, the reduced Young’s modulus and the adhesion critical loads followed similar tendencies in both sets of films. Wear rates were similar for all samples except for the one with the highest silver content. To improve brittleness of TiO2 films, the results seem to indicate that a slight metal doping is preferred, and Au showed to be a better choice than Ag. In fact, the sample with the lowest Au content revealed a better mechanical behaviour than the pure TiO2 film.This research was sponsored by FEDER funds through the COMPETE program (Programa Operacional Factores de Competitividade) and by FCT (Fundação para a Ciência e a Tecnologia), under the projects PEST-C/FIS/UI607/2013 and PEst-C/EME/UI0285/2013. The authors also acknowledge the financial support by the project Nano4color – Design and develop a new generation of color PVD coatings for decorative applications (FP7 EC R4SME Project No. 315286)
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