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Lattice Boltzmann simulations of double-diffusive convection in a rectangular cavity differentially heated and salted are conducted in the presence of internal heat generation and Dufour and Soret effects. The study is performed for an aspect ratio A = 2, an external Rayleigh number RaE = 105, a Lewis number Le = 2, a buoyancy ratio N = -1, and a Prandtl number Pr = 0.71: The study focuses mainly on the effect of Dufour number (Du = 0 and 0.5) to measure its impact on the ranges of steady/unsteady solutions reported in a previous study for the Soret parameter ranging from -0.5 to 0.5 and internal to external Rayleigh numbers ratio ranging from 0 to 80. Compared to Du = 0, the results obtained show that the presence of Dufour mechanism with a positive value leads to a destabilizing effect by widening the ranges of instability observed for the considered values of Sr: The combinations (Sr, Du) the most stabilizing/destabilizing are identified and discussed in this study. [ABSTRACT FROM AUTHOR]

This work presents an investigation on the optical and structural properties of two series of nanocomposites based on the incorporation of spherical‐ (NDs) or rod‐shaped (NRs) semiconductive crystalline titanium dioxide (TiO2) nanoparticles (NPs) into an insulating amorphous polymethylmethacrylate (PMMA) matrix. The UV–visible absorbance and reflectance measurements reveal that the increase in TiO2 NP concentration within the polymer matrix reduces the forbidden band size for both NDs and NRs, leading to an improvement of the refractive index. SEM and TEM morphological characterizations were performed to investigate the size, size distribution and NPs dispersion within the polymeric matrix. The structural analyses performed by using X‐ray diffraction show peaks ascribed to the TiO2 crystalline structure while infrared (FT‐IR) spectra indicate the occurrence of interactions between nanofillers and the polymer chain of the host matrix. [ABSTRACT FROM AUTHOR]

In the present study, the simulation of the direct carbon fuel cell (DCFC) using a hybrid Lattice Boltzmann and finite volume approach is performed. The numerical model was first validated against available experimental data. Parametric studies were carried out to investigate the effect of the microstructure of the carbon fuel on the DCFC performance. The increase of the specific surface area (SSA) or porosity was found to minimize the voltage drop in the cell and ameliorate its output power density. In contrary, the increase of the tortuosity was found to inversely affect these results.

In this paper, we asymptotically investigate a confined fluid flow in a flexible tube with a variable section. The fluid is considered to be newtonian, incompressible and it elapses in elastic and isotropic shell. This study provides a review of recent analysing the effects of the elastic wall tube properties over the fluid behaviour. The unsteady fluid flow will be analysed following the singular perturbations theory according to a large Reynolds number and a small aspect radio. The wall is assumed to be a thin shell that generate a small axisymmetric vibration. This model is mathematically developed by using the thin shell linear theory that is governed by a geodesic curvature parameter.

Ferroelectric thin films of lead titanate (PbTiO3) have been prepared on SiO2/Si(100) and LaNiO3(110)/SiO2/Si(100) substrates by a sol-gel spin coating method, using lead acetate trihydrate, and titanium isopropoxide as precursors along with 2-methoxyethanol as a solvent and acetic acid as catalyst. X-Ray Diffraction patterns show the formation of the perovskites structure of PbTiO3 thin films deposited on SiO2/Si substrates at 650°C. A SEM micrograph of the film cross-section is used to measure the thickness, which gave a value of 0.65 μm. Analysis of its ferroelectric hysteresis measurements gave values of remanent polarisation of Pr = 18.37 μC/cm2 and a coercive field of Ec = 121.53 kV/cm which are essential for non-volatile memories application. The current-voltage characteristic was found to be space charge conduction in the high voltage region and its piezoelectric coefficient d33, as measured by a Laser Scanning Doppler vibrometry, showed small linear decreases from 75 pm/V at 45 kV/cm to 67 pm/V at the highest applied field (330 kV/cm). [ABSTRACT FROM AUTHOR]

Gathering, analyzing and synthesizing large and complex sets of hydraulic, terrestrial, atmospheric, biological and socio-economic data are critical for any decision making process in the water sector. This paper aims to propose a practical approach for increasing the effectiveness of sustainable management of water resources within Integrated Water Resources Management (IWRM) framework and climate change context. The article advocates that the designed Decision Support System (DSS) is a prerequisite in proper IWRM. In fact, it offers a dedicated management system, to assist decision makers and policy makers of water in providing timely, well informed and reproducible answers to important questions, as well as transforming data into knowledge and understandable results through innovative techniques. However, to provide a Decision Support System allowing both access to geographic data needed for IWRM and steering business processes through reliable indicators, it is imperative that the system must be able to combine the geographic information system technology with Business Intelligence, so called Geo-BI (Geo-Business Intelligence). To this end, this paper presents a study that revolves around the concept of Geo-BI and aims to model a Multidimensional Decision Support System, which is a part of an extensive process of spatial data warehouse construction. [ABSTRACT FROM AUTHOR]