The vacuum thermal evaporation technique (VTET) allows the deposition of highly homogeneous thin films with excellent step coverage. This method has already shows promising results for the deposition of indium sulphide at different substrate temperature between 453 and 513 K. Indium sulphide thin films have been synthesised and deposited by vacuum thermal evaporation technique. Experimental parameters have been adjusted in order to obtain a high band gap and low absorption material at low deposition temperature, as required for photovoltaic applications. The structural, morphological and optical properties were characterised by X-ray diffraction analysis, Surface Electron Microscopy and spectrophotometry. The VTET-In2S3 thin films are homogeneous and crystallised at 513 K with direct band gap values of about 2 eV.

Nanocomposite films containing Au nanoparticles embedded in a polymer matrix were prepared by vapour phase co-deposition of Au and polymers (Teflon AF and Poly($\alpha $-methylstyrene)) in high vacuum. The microstructure of the composite materials as well as metal content strongly depend on the condensation coefficient of the Au atoms, the deposition rates of the components, the substrate temperature, and the type of polymer matrix. The condensation coefficient, which varies between 0.03 and 1, was determined from energy dispersive X-ray spectrometer (EDX) and surface profilometry. It is shown that the microstructure of nanocomposites (size, size distribution, and interparticle separation of metal clusters), which was determined by transmission electron microscopy, can be controlled by the deposition parameters and the choice of polymer matrix. The optical absorption in the visible region due to the particle plasmon resonance has a strong dependence on the metal filling factor. The correlation between the microstructure of nanocomposites and optical properties, studied using UV-Vis spectroscopy, was also established. Further more, the electrical properties of the composites were studied as a function of the metal volume fraction. It was observed that the nanocomposite films exhibit a percolation threshold at a metal volume fraction of 0.43 and 0.20 for gold nanoclusters in Teflon AF and Poly(α-methylstyrene), respectively.

In this work, a non-Fourier heat conduction model considering the effect of heat source is presented and applied into pulsed laser deposition (PLD) technique to study target temperature evolvement when the target is radiated by high-power (≥1013 W/m2) short-pulse (in the order of picosecond) laser. Under this kind of irradiation conditions, the finite propagation speed of heat wave must be taken into account. The temperature profiles obtained from our model are compared with those obtained from Fourier conduction model and non-Fourier model without heat source term. The effects of heat source and relaxation time on non-Fourier temperature evolution are emphatically studied. It is found that the effect of non-Fourier heat conduction mainly shows in that it takes the target temperature certain time to start to increase and the increasing of temperature with time is faster obviously than that of Fourier heat conduction case. As for the heat source, it plays an important role that makes surface temperature ascending quicker than the case without heat source. Results also demonstrate that with the increasing of relaxation time, the Non-Fourier effect becomes remarkable more and more. Meanwhile, the corresponding physical mechanisms are investigated in detail.

We propose a pair of approaches to account for voltage driven coils when solving 3D eddy-current problems with a discrete geometric approach. The formulation we use is based on the circulation a of the magnetic vector potential on primal edges and on a scalar potential χ on conductor primal nodes. The proposed approaches consider distributed or localized voltage sources respectively and they can be applied to general coil geometries. The results are compared with those obtained with Finite Elements.

The structural and magnetic properties of Nd2AlFe16−xMnx (x = 1, 2, 3, 4, and 5) compounds have been investigated by means of X-ray diffraction and magnetization measurements. The Nd2AlFe16−xMnx compounds have a rhomhedral Th2Zn17-type structure. There exist an anisotropic strong spontaneous magnetostriction in magnetic state and a negative thermal expansion near their Curie temperatures. The nearly zero thermal expansion coefficient is found over a broad temperature range including room temperature from 103 to 342 K for Nd2AlFe15Mn compound. In the magnetic state, the thermal expansion coefficients of Nd2AlFe16−xMnx compounds increase with the increasing Mn concentrations x. Mn concentration dependences of the lattice parameters and unit-cell volume, the spontaneous magnetostrictive deformation, the Curie temperature, and the saturation magnetization have been discussed.

There has been a renewed interest in zinc oxide in the materials science community after it was shown to be ferromagnetic when doped with cobalt. However, it has remained difficult to tell whether the origin of the phenomenon was intrinsic or due to secondary phases. Here, we examine with analytical transmission electron microscopy the distribution of cobalt in a thin film of ferromagnetic Al-doped Zn0.7Co0.3O that we have grown by pulsed laser deposition on alumina. We show that precipitation of a secondary phase does occur, but that it concerns less than 10% of the cobalt atoms. The precipitates appear to be made of hexagonal metallic Co, and their average diameter is 4 nm. Their magnetism could be the reason for the low measured Curie temperature of the sample (50 K). On the other hand, the overall measured magnetization of 0.7 $\mu_B$ per cobalt atom suggests that the Co atoms in solution are at the origin of most of the signal.

In this paper we model the thermoelectric magnetic field around isotropic inclusions in anisotropic media. It is demonstrated that while the presence of the inclusion will be the dominant source of the thermoelectric signal, the anisotropy of the host material will affect the signal. Although such a phenomenon will occur for all shapes of inclusions, for simplicity we shall demonstrate our theoretical and numerical modeling on the more mathematically tractable case of a cylindrical inclusion aligned along an axis of symmetry of an anisotropic metal medium.

The electrical supply of portable electronic devices is a crucial problem, which may be solved by harvesting a part of the mechanical energy dissipated in our environment. For the last ten years, many prototype piezoelectric generators have been proposed in research literature, offering different technological choices, but always working according to the same schematics: three different conversion stages. The first one, named mechanical application device (MAD), transforms the initial mechanical stress into a higher level or higher frequency stress. This stress is applied to the second stage, the piezoelectric device (PD). The last stage, an electronic circuit named harvesting system (HS), is essential to maximise the electrical energy delivered to the targeted electronic device. In this paper, we present an experimental test bench that can replace any association of MAD and PD. Then we describe our HS, and demonstrate its performances for our application, where the applied mechanical stress is exponential and varies with a low frequency. Thanks to this HS, the conversion from mechanical energy to electrical energy is improved, and this phenomenon can be explained by simulation, using an equivalent circuit. At last, some experimental results are commented, leading to the perspectives of this research project.

A computerized model of steady–state photon diffusion within turbid media such as biological tissues, solved by means of the Finite Element Method (FEM) is presented in this paper. Assuming that the different media are illuminated by a flat collimated laser beam source, we develop the basic theory including the suitable boundary conditions along the meshed domain. Model simulations depict firstly photon-flux density patterns in the $r-z$ plane associated with axis fluence rate profiles, plotted as functions of media properties and beam sizes. A second objective was to display both the rate of re-emitted optical power integrated by an optical fibre radially displaced away from the source and the power integrated by an optical fibre axially moved inside the tissue. Simulation studies are further extended to multilayered media such as skin and aorta, in order to describe the light propagation through these tissue structures more realistically.

In this work we have considered the R. Nayak et al. [Immunology 102, 387 (2001)] biological model – Relay Hypothesis – to study the time evolution of the clonal repertoire, including the populations of antibodies. Our results suggest that the decrease of the production of antibodies favors the global maintenance of immune memory.