13,438 research outputs found

    Design of a spiral-shaped Mach Zehnder interferometric sensor for refractive index sensing of watery solutions

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    The design of a spiral-shaped Mach-Zehnder Interferometric sensor (sMZI sensor) for refractive index sensing of watery solutions is presented. The goal of the running project is to realise a multi-sensing array by placing multiple sMZIs in series to form a sensing branch, and to place several sensing branches in parallel. In such an arrangment it is possible to use a single light source for several sensors. Each sensor will contain an electro-optical modulator, which makes it possible to separately interrogate and accurately read-out each sensor in the same sensing branch

    Depletion-induced biaxial nematic states of boardlike particles

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    With the aim of investigating the stability conditions of biaxial nematic liquid crystals, we study the effect of adding a non-adsorbing ideal depletant on the phase behavior of colloidal hard boardlike particles. We take into account the presence of the depletant by introducing an effective depletion attraction between a pair of boardlike particles. At fixed depletant fugacity, the stable liquid crystal phase is determined through a mean-field theory with restricted orientations. Interestingly, we predict that for slightly elongated boardlike particles a critical depletant density exists, where the system undergoes a direct transition from an isotropic liquid to a biaxial nematic phase. As a consequence, by tuning the depletant density, an easy experimental control parameter, one can stabilize states of high biaxial nematic order even when these states are unstable for pure systems of boardlike particles

    Sellers' hedging incentives at EPA's emission trading auction

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    Cason (1993)argued thattheauction theEPAused in order to start the market for sulfur allowances, is not efficient. The set-up of the auction gives both buyers and sellers an incentive to understate their valuation of an allowance. In this paper, we show that the sellers’ incentives are even more perverse than Cason suggested. In particular, we show that sellers have an incentive to set their ask price equal to zero, while simultaneously hedging their bets by submitting a positive bid. It is not possible to derive the Nash equilibrium for this set-up. If such an equilibrium exists, sellers either set only a positive ask price, or an ask price equal to zero, and a positive bid as well.

    Nano-flow thermal sensor applying dymamic w-2w sensing method

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    This article presents microchannel thermal flow sensors fabricated using standard micromachining technology. The sensors comprise of a SiXNY microchannel created by etching of a poly-Si sacrificial layer. The channels are released by KOH etching through inlets and outlets etched from the backside of the substrate. Liquid flow is measured by platinum resistors deposited on top of the microchannel, while the channel is thermally isolated from the substrate by a SiXNY membrane. Flow rates of DI water in the order of nlâ‹…min-1 have been measured using a dynamic sensing method applying heat waves

    Free Minimization of the Fundamental Measure Theory Functional: Freezing of Parallel Hard Squares and Cubes

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    Due to remarkable advances in colloid synthesis techniques, systems of squares and cubes, once an academic abstraction for theorists and simulators, are nowadays an experimental reality. By means of a free minimization of the free-energy functional, we apply Fundamental Measure Theory to analyze the phase behavior of parallel hard squares and hard cubes. We compare our results with those obtained by the traditional approach based on the Gaussian parameterization, finding small deviations and good overall agreement between the two methods. For hard squares our predictions feature at intermediate packing fraction a smectic phase, which is however expected to be unstable due to thermal fluctuations. This implies that for hard squares the theory predicts either a vacancy-rich second-order transition or a vacancy-poor weakly first-order phase transition at higher density. In accordance with previous studies, a second-order transition with a high vacancy concentration is predicted for hard cubes

    A spiral-shaped mach-zehnder interferometric sensor for monitoring thickness changes in bioreceptor layers

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    Design issues of a spiral-shaped Mach-Zehnder interferometer are discussed
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