2,186 research outputs found

    A digital twin framework for Industry 4.0 enabling next-gen manufacturing

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    Digital twins offer a framework to support the ever-rising demands in the fast-paced industrial evolution. This technology not only adds to the reliability of industrial processes but also offers an insight in to long-term behaviors and pattern during the aging of the industrial equipment. In this paper, a digital twin framework is presented to replicate the processes of a real production line for product assembly. The proposed work implements a digital/graphical replica of Festo Cyber Physical Factory (CPF) for Industry 4.0 (I4.0). The implemented system allows to schedule orders and specify product configuration which embodies the actions of CPF in digital world. In addition, the paper also presents a viable framework to interlink the physical system with the digital instance to offer extended services and a pathway towards realization of fully functional digital twins

    DEVELOPMENT OF POLYRROLE THIN FILM BASED SOLID-CONTACT ION-SELECTIVE ELECTRODES FOR NITRATE AND NITRITE

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    Joint Research on Environmental Science and Technology for the Eart

    Helminth eggs die-off and nutrients : human excreta storage experiment

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    Are the current practices of handling human excreta for agricultural purposes by farmers in Vietnam good enough?This study set up an excreta storage experiment to research how to inactivate Ascaris lumbricoides eggs and stillmaintain the nutrient value of human excreta

    ULTRA-TRACE DETERMINATION OF IRIDIUM BY ETV/ICP-MS USING CHEMICAL MODIFIERS

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    Joint Research on Environmental Science and Technology for the Eart

    INSIGHT INTO NANOPARTICLE CHARGING MECHANISM IN NONPOLAR SOLVENTS TO CONTROL THE FORMATION OF PT NANOPARTICLE MONOLAYERS BY ELECTROPHORETIC DEPOSITION

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    Electrophoretic deposition of nanoparticles is considered to be one of the convenient methods for preparation of ordered nanoparticle monolayers. By using a nonpolar suspension of nanoparticles, we can (a) limit the current between the electrodes; (b) reduce the changes in the composition and conductivity of the medium due to the generation of charged species near the electrodes; and (c) suppress electrochemical reactions at the electrodes. One of the important questions about understanding the principle mechanisms of electrophoretic deposition is to identify the origin of electric charge in nonpolar suspension from which the nanoparticles are deposited. We developed a simple model of nanoparticle charging and we explained how the amount of the charge carried by nanoparticles can affect the quality of deposited monolayers. For electrophoretic deposition, we used silicon substrates as electrodes and Pt nanoparticles in water-AOT-isooctane reverse micellar system as a suspension. We used the centrifugation of Pt in combination with DLS measurements for controlling the charge carried by nanoparticles. Prepared nanoparticle monolayers were analyzed by AFM, SEM and electrical measurements. Please click Additional Files below to see the full abstract

    PREPARATION AND CHARACTERIZATION OF LOW RESISTIVITY CuS FILMS USING SPRAY PYROLYSIS

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    CuS films were prepared by spray pyrolysis from solutions of (NH 2 ) 2 CS and CuCl 2 .2H 2 O mixed at ratios of 3:1, 4:1 and 5:1 on glass substrates heated at 160 to 240 o C. The deposition temperatures and pulsed regime of spray were controlled with the help of electronic equipments. The resistivity, phase composition, morphology, band gap energy and type of conductivity of the films were characterized using volt-ampere, XRD, SEM, optical absorption and Hall effect measurements. It was found that for all ratios of precursors the low resistivity of the films was stably obtained at substrate temperatures from 170 to 220 o C. Among them the lowest sheet resistivity of the films reached value of 8 ohm/sqr. The influences of deposition temperature and material ratio on characteristics of the spray deposited CuS films were discussed

    CONTAMINATION BY ARSENIC AND LEAD IN RESIDENTS FROM VIETNAM

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    Joint Research on Environmental Science and Technology for the Eart

    Bayesian inverse problems for recovering coefficients of two scale elliptic equations

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    We consider the Bayesian inverse homogenization problem of recovering the locally periodic two scale coefficient of a two scale elliptic equation, given limited noisy information on the solution. We consider both the uniform and the Gaussian prior probability measures. We use the two scale homogenized equation whose solution contains the solution of the homogenized equation which describes the macroscopic behaviour, and the corrector which encodes the microscopic behaviour. We approximate the posterior probability by a probability measure determined by the solution of the two scale homogenized equation. We show that the Hellinger distance of these measures converges to zero when the microscale converges to zero, and establish an explicit convergence rate when the solution of the two scale homogenized equation is sufficiently regular. Sampling the posterior measure by Markov Chain Monte Carlo (MCMC) method, instead of solving the two scale equation using fine mesh for each proposal with extremely high cost, we can solve the macroscopic two scale homogenized equation. Although this equation is posed in a high dimensional tensorized domain, it can be solved with essentially optimal complexity by the sparse tensor product finite element method, which reduces the computational complexity of the MCMC sampling method substantially. We show numerically that observations on the macrosopic behaviour alone are not sufficient to infer the microstructure. We need also observations on the corrector. Solving the two scale homogenized equation, we get both the solution to the homogenized equation and the corrector. Thus our method is particularly suitable for sampling the posterior measure of two scale coefficients

    Noncommutative gravity: fuzzy sphere and others

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    Gravity on noncommutative analogues of compact spaces can give a finite mode truncation of ordinary commutative gravity. We obtain the actions for gravity on the noncommutative two-sphere and on the noncommutative CP2{\bf CP}^2 in terms of finite dimensional (N×N)(N\times N)-matrices. The commutative large NN limit is also discussed.Comment: LaTeX, 13 pages, section on CP^2 added + minor change

    Theory of Exciton Recombination from the Magnetically Induced Wigner Crystal

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    We study the theory of itinerant-hole photoluminescence of two-dimensional electron systems in the regime of the magnetically induced Wigner crystal. We show that the exciton recombination transition develops structure related to the presence of the Wigner crystal. The form of this structure depends strongly on the separation dd between the photo-excited hole and the plane of the two-dimensional electron gas. When dd is small compared to the magnetic length, additional peaks appear in the spectrum due to the recombination of exciton states with wavevectors equal to the reciprocal lattice vectors of the crystal. For dd larger than the magnetic length, the exciton becomes strongly confined to an interstitial site of the lattice, and the structure in the spectrum reflects the short-range correlations of the Wigner crystal. We derive expressions for the energies and the radiative lifetimes of the states contributing to photoluminescence, and discuss how the results of our analysis compare with experimental observations.Comment: 10 pages, no figures, uses Revtex and multicol.st
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