2,004 research outputs found
Asymptotic description of solutions of the exterior Navier Stokes problem in a half space
We consider the problem of a body moving within an incompressible fluid at
constant speed parallel to a wall, in an otherwise unbounded domain. This
situation is modeled by the incompressible Navier-Stokes equations in an
exterior domain in a half space, with appropriate boundary conditions on the
wall, the body, and at infinity. We focus on the case where the size of the
body is small. We prove in a very general setup that the solution of this
problem is unique and we compute a sharp decay rate of the solution far from
the moving body and the wall
Syntheses, Structures, and Photophysical Properties of Mono- and Dinuclear Sulfur-Rich Gold(I) Complexes
Sulfur-rich 1,2 dithiolene and neutral thione ligands were used for the synthesis of gold complexes, some of them exhibiting aurophilic interactions. Surprisingly, the closest Au···Au contact is observed in an unsupported dinuclear complex, which makes part of a supramolecular network. Photophysical studies, combined with DFT calculations, indicate that the participations of the Au···Au interactions have some relevance to the rich luminescence properties of these compounds
Integral potential method for a transmission problem with Lipschitz interface in R^3 for the Stokes and Darcy–Forchheimer–Brinkman PDE systems
The purpose of this paper is to obtain existence and uniqueness results in weighted Sobolev spaces for transmission problems for the non-linear Darcy-Forchheimer-Brinkman system and the linear Stokes system in two complementary Lipschitz domains in R3, one of them is a bounded Lipschitz domain with connected boundary, and the other one is the exterior Lipschitz domain R3 n. We exploit a layer potential method for the Stokes and Brinkman systems combined with a fixed point theorem in order to show the desired existence and uniqueness results, whenever the given data are suitably small in some weighted Sobolev spaces and boundary Sobolev spaces
Antioxydant activity, oxidative stability properties of Colza oil, comparison of mechanical agitated and ultrasonic extraction on green tea catechins of Camellia sinensis L.
peer reviewedUltrasonic extraction “UE” used to optimize the extraction yield of phenolic compounds “PC” from green tea Camellia sinensis L., and compared with mechanical agitated extraction “MAE”.
UE was applied at different times (15, 10 and 5min) and temperatures (25, 60 and 95°C) and MAE was performed at these experimental conditions (15 min, 95°C, 400 rpm). Results demonstrate that the maximum yield of epigallocatechin 3-gallate “EGCG” extracted by UE was significantly (P < 0.05) higher than that obteined using MAE (136 mg/g vs 100 mg/g, respectively). The optimum conditions for the polyphenol compounds “PC” recovery are obtained using UE during 15 min at 95°C (~134.66 mg/g). Four catechins from extracted PC were identified using high-performance liquid chromatography equipped with a diode array detector and liquid chromatography mass spectrometry “HPLC-DAD & LC-MS”: epigallocatechin “EGC”, epicatechin “EC”, epigallocatechingallate “EGCG”, and epicatechin-gallate “ECG”. EGCG is the major compound in polyphenol extracts representing 60 %. The antioxidant capacity of the obtained extracts was also studied. Diphényl-2-pycril-hydrazyl “DPPH” scavenging activity is higher for UE than MAE (~ 90 % vs ~85%). Moreover, the PC obtained by UE added to colza oil had a higher oxidative stability, determined by rancimat than those extracted by MAE method (~30.62 h vs ~21.26 h). Results indicate the suitability of UE method for production of PC as potent antioxidant for stabilization of vegetable oils such as colza oil
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Day-ahead industrial load forecasting for electric RTG cranes
Given the increase in international trading and the significant energy and environmental challenges in ports around the world, there is a need for a greater understanding of the energy demand behaviour at ports. The move towards electrified rubber-tyred gantry (RTG) cranes is expected to reduce gas emissions and increase energy savings compared to diesel RTG cranes but it will increase electrical energy demand. Electrical load forecasting is a key tool for understanding the energy demand which is usually applied to data with strong regularities and seasonal patterns. However, the highly volatile and stochastic behaviour of the RTG crane demand creates a substantial prediction challenge. This paper is one of the first extensive investigations into short term load forecasts for electrified RTG crane demand. Options for model inputs are investigated depending on extensive data and correlation analysis. The effect of estimation accuracy of exogenous variables on the forecast accuracy is investigated as well. The models are tested on two different RTG crane data sets that were collected from the Port of Felixstowe in the UK. The results reveal the effectiveness of the forecast models when the estimation of the number of crane moves and container gross weight are accurate
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Z boson production in Pb+Pb collisions at √Snn = 5.02 TeV measured by the ATLAS experiment
The production yield of Z bosons is measured in the electron and muon decay channels in Pb+Pb collisions at √S = 5.02 TeV with the ATLAS detector. Data from the 2015 LHC run corresponding to an integrated luminosity of 0.49 nb are used for the analysis. The Z boson yield, normalised by the total number of minimum-bias events and the mean nuclear thickness function, is measured as a function of dilepton rapidity and event centrality. The measurements in Pb+Pb collisions are compared with similar measurements made in proton-proton collisions at the same centre-of-mass energy. The nuclear modification factor is found to be consistent with unity for all centrality intervals. The results are compared with theoretical predictions obtained at next-to-leading order using nucleon and nuclear parton distribution functions. The normalised Z boson yields in Pb+Pb collisions lie 1-3σ above the predictions. The nuclear modification factor measured as a function of rapidity agrees with unity and is consistent with a next-to-leading-order QCD calculation including the isospin effect. nn -
Measurement of J/ψ production in association with a W ± boson with pp data at 8 TeV
A measurement of the production of a prompt J/ψ meson in association with a W± boson with W± → μν and J/ψ → μ+μ− is presented for J/ψ transverse momenta in the range 8.5–150 GeV and rapidity |yJ/ψ| < 2.1 using ATLAS data recorded in 2012 at the LHC. The data were taken at a proton-proton centre-of-mass energy of s = 8 TeV and correspond to an integrated luminosity of 20.3 fb−1. The ratio of the prompt J/ψ plus W± cross-section to the inclusive W± cross-section is presented as a differential measurement as a function of J/ψ transverse momenta and compared with theoretical predictions using different double-parton-scattering cross-sections. [Figure not available: see fulltext.]
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