1,246 research outputs found

    Free Vibration Analysis Of The Moderately Thick Laminated Composite Rectangular Plate On Two-Parameter Elastic Foundation With Elastic Boundary Conditions

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    An improved Fourier series method is presented for the free vibration analysis of the moderately thick laminated composite rectangular plate with general elastic supports and point supports resting on an elastic foundation. The approach is based on the first order shear deformation theory and foundation effect using two-parameter Pasternak foundation model. The displacement and rotation functions are generally sought, regardless of boundary conditions, as Fourier series and supplementary functions. All the series expansion coefficients are determined using the Rayleigh-Ritz technique. The excellent accuracy of the current results is validated by comparing them with existing results

    Charged bottomonium-like structures Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650)

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    The observation of two charged bottomonium-like structures Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650) has stimulated extensive studies of the properties of Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650). In this talk, we briefly introduce the research status of Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650) combined with our theoretical progress.Comment: 6 pages, 1 table, 5 figures. Plenary talk given at the international conference The Fifth Asia-Pacific Conference on Few-Body Systems in Physics 2011 (APFB2011), Seoul, Republic of Korea, 22-26 August 201

    An Efficient Sensitivity Analysis Method for Optimization of Vehicle Random Vibrations

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    AbstractAn efficient and accuracy sensitivity analysis method for optimal analysis of random vibration of vehicle-bridge coupled system is purposed. The pseudo-excitation method is used to transform random road surface roughness into a series of deterministic harmonic excitations, and then the precise integration method is adopted to compute vehicle/bridge system response. The pseudo-excitation method and the precise integration method are both accurate and efficient, so that the first and second order sensitivity information of the responses can be obtained very conveniently. Taking ride comfort as the objective function, an optimal analysis for a vehicle/bridge system is performed

    Scalable, Time-Responsive, Digital, Energy-Efficient Molecular Circuits using DNA Strand Displacement

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    We propose a novel theoretical biomolecular design to implement any Boolean circuit using the mechanism of DNA strand displacement. The design is scalable: all species of DNA strands can in principle be mixed and prepared in a single test tube, rather than requiring separate purification of each species, which is a barrier to large-scale synthesis. The design is time-responsive: the concentration of output species changes in response to the concentration of input species, so that time-varying inputs may be continuously processed. The design is digital: Boolean values of wires in the circuit are represented as high or low concentrations of certain species, and we show how to construct a single-input, single-output signal restoration gate that amplifies the difference between high and low, which can be distributed to each wire in the circuit to overcome signal degradation. This means we can achieve a digital abstraction of the analog values of concentrations. Finally, the design is energy-efficient: if input species are specified ideally (meaning absolutely 0 concentration of unwanted species), then output species converge to their ideal concentrations at steady-state, and the system at steady-state is in (dynamic) equilibrium, meaning that no energy is consumed by irreversible reactions until the input again changes. Drawbacks of our design include the following. If input is provided non-ideally (small positive concentration of unwanted species), then energy must be continually expended to maintain correct output concentrations even at steady-state. In addition, our fuel species - those species that are permanently consumed in irreversible reactions - are not "generic"; each gate in the circuit is powered by its own specific type of fuel species. Hence different circuits must be powered by different types of fuel. Finally, we require input to be given according to the dual-rail convention, so that an input of 0 is specified not only by the absence of a certain species, but by the presence of another. That is, we do not construct a "true NOT gate" that sets its output to high concentration if and only if its input's concentration is low. It remains an open problem to design scalable, time-responsive, digital, energy-efficient molecular circuits that additionally solve one of these problems, or to prove that some subset of their resolutions are mutually incompatible.Comment: version 2: the paper itself is unchanged from version 1, but the arXiv software stripped some asterisk characters out of the abstract whose purpose was to highlight words. These characters have been replaced with underscores in version 2. The arXiv software also removed the second paragraph of the abstract, which has been (attempted to be) re-inserted. Also, although the secondary subject is "Soft Condensed Matter", this classification was chosen by the arXiv moderators after submission, not chosen by the authors. The authors consider this submission to be a theoretical computer science paper

    U-model enhanced dynamic control of a heavy oil pyrolysis/cracking furnace

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    This paper proposes a case study in the control of a heavy oil pyrolysis/cracking furnace with a newly extended U-Model based Pole Placement Controller (U-PPC). The major work of the paper includes: 1. establishing a control oriented nonlinear dynamic model with Naphtha cracking and thermal dynamics, 2. analysing a U-model (i.e. control oriented prototype) representation of various popular process model sets, 3. designing the new U-PPC to enhance the control performance in pole placement and stabilisation, 4) taking computational bench tests to demonstrate the control system design and performance with a user-friendly step by step procedure

    Compact graphene mode-locked wavelength-tunable erbium-doped fiber lasers: from all anomalous dispersion towards all normal dispersion

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    Soliton operation and soliton wavelength tuning of erbium-doped fiber lasers mode locked with atomic layer graphene was experimentally investigated under various cavity dispersion conditions. It was shown that not only wide range soliton wavelength tuning but also soltion pulse width variation could be obtained in the fiber lasers. Our results show that the graphene mode locked erbium-doped fiber lasers provide a compact, user friendly and low cost wavelength tunable ultrahsort pulse source

    Operation of a DNA-Based Autocatalytic Network in Serum

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    The potential for inferring the presence of cancer by the detection of miRNA in human blood has motivated research into the design and operation of DNA-based chemical amplifiers that can operate in bodily fluids. As a first step toward this goal, we have tested the operation of a DNA-based autocatalytic network in human serum and mouse serum. With the addition of sodium dodecyl sulfate to prevent degradation by nuclease activity, the network was found to operate successfully with both DNA and RNA catalysts

    Flux transitions in a superconducting ring

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    We perform a numeric study of the flux transitions in a superconducting ring at fixed temperature, while the applied field is swept at an ideally slow rate. The current around the ring and its free energy are evaluated. We partially explain some of the known experimental features, and predict a considerably large new feature: in the vicinity of a critical field, giant jumps are expected

    The anti-caries efficacy of a dentifrice containing 1.5% arginine and 1450ppm fluoride as sodium monofluorophosphate assessed using Quantitative Light-induced Fluorescence (QLF)

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    AbstractObjectiveTo compare the efficacy of a new dentifrice containing 1.5% arginine, an insoluble calcium compound and 1450ppm fluoride to arrest and reverse naturally occurring buccal caries lesions in children relative to a positive control dentifrice containing 1450ppm fluoride alone.Study designParticipants from Chengdu, Sichuan Province, China tested three dentifrices: a new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450ppm fluoride, as sodium monofluorophosphate, a positive control dentifrice containing 1450ppm fluoride, as sodium fluoride, in a silica base, and a matched negative control dentifrice without arginine and fluoride. Quantitative Light-induced Fluorescence (QLF) was used to assess buccal caries lesions at baseline and after 3 and 6 months of product use.Results438 participants (initial age 9–13 years (mean 11.1±0.78) and 48.6% female) completed the study. No adverse events attributable to the products were reported during the course of the study. The subject mean ΔQ (mm2%), representing lesion volume, was 27.26 at baseline. After 6 months of product use, the ΔQ values for the arginine-containing, positive and negative control dentifrices were 13.46, 17.99 and 23.70 representing improvements from baseline of 50.6%, 34.0% and 13.1%. After 6 months product use, the differences between the pair wise comparisons for all three groups were statistically significant (p<0.01). The arginine-containing dentifrice demonstrated an improvement after only 3 months that was almost identical to that achieved by the conventional 1450ppm fluoride dentifrice after 6 months.ConclusionThe new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450ppm fluoride provides statistically significantly superior efficacy in arresting and reversing buccal caries lesions to a conventional dentifrice containing 1450ppm fluoride alone
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