Various properties of spinel iron oxide nanoparticles are reviewed in relation to the control of the particle size and the control of their dispersion in a variety of matrices. The deep knowledge of the different synthesis parameters and the interfacial oxide-solution characteristics allows to prepare a large variety of materials like calibrated nanoparticles and inorganic or hybrid nanocomposites.

The spectral signatures of non-axially excited, absorbing TFHBM slabs are determined, after using a single-resonance Lorentzian model to describe the dispersive properties of the medium. Optical phenomena such as the optical rotation, circular dichroism and ellipticity transformation by absorbing TFHBM slabs are described. The effect of absorption on the functionality of TFHBM-based devices, such as multi-notch filters and ultranarrow-bandpass filters, are noted and engineering guidelines on the fabrication of such devices are provided.

The nature of the hydrogen bonding and content and their influence on the film microstructure have been investigated in detail, as a function of the H2 dilution and the residual pressure, in hydrogenated amorphous silicon (a-Si:H) films prepared by radiofrequency (rf) magnetron sputtering at a common substrate temperature (~ 250 °C) and pressure (5 × 10−4 torr) and high rates (11−15 Å/s). H2 percentages in the gas phase mixture (Ar + % H2) of 5, 10, 15 and 20% have been introduced during growth. For the 20% of H2, two different pressures of 5 × 10−4 and 50 × 10−4 torr were used. A combination of infrared absorption, optical transmission and elastic recoil detection analysis experiments have been carried out to fully characterize the samples in their as-deposited state. The results clearly indicate that for H2 percentage equal to or lower than 15% , the total bonded H content in the films increases as the H2 percentage increases, and then reaches a saturation value or even decreases for higher H2 percentage. Moreover, the microstructure is also found to be deeply affected by the H2 dilution and pressure. In particular, for high H2 percentage (20%) and high pressure (50 × 10−4 torr), unbounded H as well as polyhydride (Si-H2)n chains, possibly located in structural inhomogeneities such as voids, are also present in the films in addition to the isolated monohydride Si-H and polyhydride Si-H2 complexes. As a result, a reduction of the compactness of the film structure associated with a decrease of the refractive index n is observed. The optical gap is found to be rather controlled by the total bonded hydrogen content. The lowest proportion of isolated polyhydride Si-H2 complexes and the highest density are observed for films deposited with 10% of H2 in the gas phase and a pressure of 5 × 10−4 torr.

Metal nanoparticles (gold, silver, copper) that are embedded in an insulating organic host material exhibit optical plasma resonance absorption in the visible and near-infrared region. The spectral position, the half width and the intensity of the plasma resonance absorption all depend on the particle size, the particle shape, and the optical behavior of the cluster and the host material.The optical extinction of various gold, silver or copper particle assemblies embedded in plasma polymer or gelatin was measured at 4.2 K and 1.2 K as well as at room temperature. The packing density of several samples was high enough to resolve a reversible increase of the plasma resonance absorption intensity towards lower temperatures. Additionally, at larger silver particles $D_{\rm m} >50$ nm a significant blue shift of the plasma resonance absorptionwas measured. Particle size and shape distribution were determined by transmissionelectron microscopy (TEM). For the first time, simultaneous measurements of the electrical and optical properties at one and the same particle assembly were performed at low temperatures. Contrary to the increasing optical extinction, the d.c. conductivity decreased to two orders of magnitude. At silver particles embedded in a plasma polymer made from thiophene a significant photocurrent was measured.

In this paper, a new concept called "Floating Islands diode" (FLI-diode) is proposed: the voltage handling capabilityof this new diode is assumed by the association of several PN junctions in series. This concept can be applied to anypower devices (lateral or vertical). An example of vertical power MOSFET based on this concept is presented here: thisnew structure, called "FLIMOSFET", exhibits improved on-state resistance performance when compared to the conventional VDMOSFET. For instance, for a breakdown voltage of 900 volts, the theoretical performance are strongly improved in term of specific on-resistance (reduction of about 70% relative to the conventional structure and 40% relative to thesilicon limit). Moreover the specific on-resistance theoretical limits of FLIMOSFET family are determined and comparedto those of the "Superjunction" MOS Transistor family: this comparison shows the strong interest of the FLIMOSFET inthe 200 volts-1000 volts breakdown voltage range.

The stable corona discharge has found use in a large number of electrostaticapplications and one of their important properties is the inception voltage which can beeasily and accurately measured. The empirical Peek's law which yields the corona inceptionfield is previously made in standard air for wire-to-cylinder geometry and used for manyyears. However, the generalisation of this law, which at present derives from Hartmann'sphysical-mathematical model, requires new measurements with varying air physical parameters.This classical law expresses the inception field at the anode surface in function of theanode diameter, the related air density and the humidity. New measurement method ofthepositive DC corona-current voltage characteristics have been introduced in a wire-to-cylinderand wire-to-plane systems. Remarkable similarities between these basically different systemsare shown in this paper and the steady corona-current voltage characteristics are describedby the Townsend's square law in a large range of related air density. The normalizationfactor at air density equals unity and the humidity function suggested by the model are also determined from the measurements. The model values of the inception field at the wire surfaceagree with measured values in both wire-to-cylinder and wire-to-plane systems.

We study two-phase flow in a tall vertical slot differently heated from the side walls, where one of the phase is fluid and another phase consists of small solid particles. The particles are subjected to downward drag exerted by the gravity and the drag exerted by finite-frequency horizontal vibrations along the layer. In the framework of the generalized Boussinesq approximations we derive non-contradictive set of governing equations describing the dynamics of suspension. The pulsed base flow is obtained and its linear stability is analysed. The comparison of the numerical results with the recent experimental findings is given.

A method founded on the follow-up of an electromagnetic cavity resonant frequency working round 390 MHz has been carried out in order to measure the void rates of bubble field induced by a 308 kHz ultrasonic cavitation in liquids. This method can detect void rates as low as 2 × 10−5. The experimental set up permits to study the influence of some experimental parameters on the void rate, such as the acoustic power, the acoustic irradiation duration, and the dissolved gas concentration in the liquid. Moreover, an estimation of the bubble size distribution is obtained. The extension of the method to open resonators and the possibility to observe the fast evolutions of the void rate are considered.