The objective of this work is to approach the possibilities of stimulated infrared thermography in dimensional characterization of defects situated in mural paintings. Towards this end, we have proceeded in two stages. Initially, we have developed, with the help of a point source photothermal analysis, an in situ measurement of the longitudinal thermal diffusivity parameter. Then, we have proceeded to the characterization of the depth of the studied defect, by means of a wide photothermal analysis and of a confrontation between theory and experiment. In this article, we present these two measurement techniques and show that the approach allows a good estimation of the depth of an inclusion of plastazote in a copy of the “Saint Christophe” of the “Campana” collection of the “Louvre Museum”.

In this work, we present various examples of assistance to the restoration of works of art by stimulated infrared thermography. We show initially that the method allows the detection of delamination located in mural paintings, such as in the “Saint Christophe” of the Campana collection of the Louvre French museum. We show then that it also makes it possible to detect delaminations or galleries of worms in marquetries. We show in a third stage that it provides for the detection of detachment of grayness in stained glasses. We show in a fourth stage that it allows the visualization of shards or metal inserts located in a Greek “panathénaque” amphora of the French National museum of the Ceramics of Sevres. We show finally, that the method permits the detection of a crack located in an ovoid vase of the same French National museum of the Ceramics of Sevres.

Based on the dielectric-continuum model and Loudon’s crystal model, the propagating optical phonons and electron-phonon interactions are studied by using the determinate method. The dispersions and electron-phonon coupling functions of the propagating optical phonons are investigated for wurtzite GaN/ZnO single quantum well (QW). The numerical results show that there are infinite propagating phonon branches by a quantum number m in the two regions. The propagating optical phonons are more dispersive for decreasing m. Moreover, the electron-phonon coupling functions have oscillating behavior in barrier layer (GaN), the periods of electron-phonon coupling functions in low frequency region are larger than those in high frequency region. The electron-phonon coupling functions of propagating phonon modes in low frequency region are more important than those in high frequency region.

This study investigated the stability of shock-waves in brittle granular materials and thus determined whether materials, such as sand, could be represented by a Hugoniot equation to describe their shock response. A series of plate impact experiments on quasi-mono-disperse soda-lime glass microspheres was conducted with the aim of measuring the shock-wave profile to determine if there was any change over time/run distance. Granular bed thickness and input stress were varied to study the effects of dispersion on shock-wave velocity (Csh). It has been shown that it is possible to sustain steady shock-waves in brittle granular materials due to no measurable wave dispersion occurring in the samples tested. This study also highlighted an unsteady precursor wave that is present in the wave profiles at low stresses.

GaAs crystal presents some interesting perspectives for resonant biosensors due to its piezoelectric and good mechanical properties and the opportunity to bio-functionalize the surface. Moreover, GaAs can be micromachined by wet etching in several solutions, which constitutes a batch and low-cost process of fabrication. The lateral field excitation (LFE) is used to generate bulk acoustic waves. The main advantage of LFE is the possibility to measure in liquid media, moreover reduced aging and increased frequency stability are also ensured. In this study, an analytical modelization is used to determine the orientations of the vibrating membrane and the electric field that give satisfactory metrological performances. Electrical performances are discussed as a function of geometrical parameters. A simulation based on a Finite Element Modelization is performed in order to optimize the design of the resonant structure. The microfabrication process of the structure is presented. The choice of etchants is discussed in terms of etching rates and surface textures. Several steps of the fabrication of the sensing area structure are shown and characterized. Finally, the active area is fabricated according to the theoretical and experimental results of this study.

A relevant modeling-method of distributed interconnect line for the high-speed signal integrity (SI) application is introduced in this paper. By using the microwave and transmission line (TL) theory, the interconnect lines are assumed as its distributed RLC-model. Then, based on the transfer matrix analysis, the second-order global transfer function of the interconnect network comprised of the TL driven by voltage source including its internal resistance and the impedance load is expressed. Thus, mathematical analysis enabling the physical SI-parameters’ extraction was established by using the transient response of the loaded line. To verify the relevance of the developed model, RC- and RLC-lines excited by square-wavepulse with 10-Gbits/s-rate were investigated. So, comparisons with SPICE-computations were performed. As results, transient responses perfectly well correlated to the reference SPICE-models were evidenced. As application of the introduced model, evaluations of rise-/fall-times, propagation delays, signal attenuations and even the settling times were realized for different values of TL-parameters. Compared to other methods, the computation execution time and data memory consumed by the program implementing the proposed delay modeling-method algorithm are much better.

Three-dimensional atomic magnetometry scheme is proposed and experimented. The scheme uses only one laser beam and can measure three components of the magnetic field independently. Spin-exchange-relaxation-free regime is verified by magnetic resonance measurement. The open loop scale factors of −2.722 mV/nT, −1.452 mV/nT and 0.076 mV/nT for the three axes are characterized. The model considering the frequency response and linewidth variation can fit the measurement data well. As only one laser beam is required, the magnetometry is easy to be realized on chip scale and is particularly attractive for applications requiring low power, low cost and high precision at the same time.

CaCu3Ti4O12 (CCTO) powder was synthesized by the combustion method. The effect of sintering temperature was studied on dielectric properties of the prepared ceramic samples. They have the dielectric constant of ~31 000 and 80 000 for the grain size of 0.3 and 30–100 μm. It is unusual for CCTO with a grain size of 0.3 μm to have a dielectric constant of ~31 000. Their giant dielectric constant could be explained by a two-step internal-barrier-layer-capacitor model, associated with grain boundaries and domain boundaries. The existence of domain boundaries helped to explain the contradiction of the dielectric mechanisms between polycrystalline and single-crystal CCTO.

The venous circulation in the lower limb is mainly controlled by the muscular action of the calf. To study the mechanisms governing the venous draining and filling process in such a situation, an experimental setup, composed by a collapsible tube under external pressure, has been built. A valve preventing back flows is inserted at the bottom of the tube and allows to model two different configurations: physiological when the fluid flow is uni-directional and pathological when the fluid flows in both directions. Pressure and flow rate measurements are carried out at the inlet and outlet of the tube and an original optical device with three cameras is proposed to measure the instantaneous cross-sectional area. The experimental results (draining and filling with physiological or pathological valves) are confronted to a simple one-dimensional numerical model which completes the physical interpretation. One major observation is that the muscular contraction induces a fast emptying phase followed by a slow one controlled by viscous effects, and that a defect of the valve decreases, as expected, the ejected volume.

This article describes the influence of the magnetic field on a small amount of residual Fe3+ ion impurities contained in a sapphire resonator excited on a whispering gallery mode and cooled down to 4 K. The energy levels and transition probabilities between pairs of levels of the system are calculated in order to determine the effect of the magnetic field on the maser output power and also on the pump power threshold.

We study the problem of scattering by a thin and conducting screen perforated periodically with square apertures, when the screen is illuminated by an electromagnetic wave in subwavelength regime. Our formulation extends the monomodal approximation technique up to the second-order Floquet modes, which enable us to investigate not only propagation mode, but also nonpropagation mode in the low-frequency regime. We also study dispersion relation of the principal Floquet modes and show the behavior of electromagnetic fields in the periodic system at the extremely low frequency, the resonance frequency and Wood’s anomaly frequency. The interesting characteristics of the fields can be found in these specific frequencies.

In this paper, we study the optical, optoelectronic and photoluminescence properties of stain-etched porous silicon nanostructures obtained with different etching times. Special attention is given to the use of the stain-etched PS as an antireflection coating as well as for surface passivating capabilities. The surface morphology has been analyzed by scanning electron microscopy. The evolution of the Si-O and Si-H absorption bands was analyzed by Fourier transform infrared spectrometry before and after PS treatment. Results show that stain etching of the silicon surface drops the total reflectivity to about 7% in the 400–1100 nm wavelength range and the minority carrier lifetime enhances to about 48 μs.

In this work a new passivation method is proposed for multicrystalline silicon wafers. This method combines the use of porous silicon (PS) and silicon nitride (SiN) coating. SiN thin film is deposited on porous silicon by the plasma-enhanced chemical vapor deposition (PECVD) technique at low temperature and investigated as a passivating and an antireflection coating. We demonstrate that silicon nitride-covered porous silicon is capable of giving an outstanding surface passivation quality on mc-Si. PS-SiN passivation on mc-Si leads to an effective minority carrier lifetime of 100 μs, which is among the highest lifetimes attained on this kind of material. This high effective lifetime results not only from the excellent degree of surface passivation but also from the grain boundaries and bulk passivation. The surface reflectivity was dramatically reduced from 27% for untreated Si wafer to about 5% after PS-SiN coating in the 400–1100 nm wavelength range.

Investigations of surface alloys are important in various applications such as that of heterogeneous catalysis, where the electronic structure and geometric arrangement of the surface atoms strongly influence the reactions taking place on the surface. So, a deeper understanding of the physical and chemical phenomena associated with the creation of surface alloys appears to be essential in order to further progress in catalysis. In this paper, we present the calculation of vibrational properties of the Cu(1 1 0)-2×1-Pd surface alloy formed by depositing Pd atoms onto the Cu(1 1 0) surface substrate. The surface phonon frequencies and local vibration density of state (LDOS) are calculated with the use of the matching theory. New surface modes have been found on the Cu(1 1 0)-2×1-Pd surface alloy along the directions of high-symmetry ΓX¯$ \overline{{\Gamma X}}$, XS¯$ \overline{{XS}}$, SY¯$ \overline{{SY}}$ and YΓ¯$ \overline{Y\mathrm{\Gamma }}$ of the two-dimensional Brillouin zone, in comparison with the clean surface Cu(1 1 0). From the calculated local phonon densities of states (LDOS) we find that the layer DOS start to settle at the fourth layer, where there are only small differences with the bulk DOS spectrum.