Thermally-induced grain boundary grooving has typically been characterized experimentally by either (1) optical interferometry (OI) or (2) reference line (RL) technique. For the OI technique, groove angle and groove width are reported and for the RL technique, groove angle, width and depth are reported. Even recent Atomic Force Microscope (AFM) studies of grain boundary grooving report their results in terms of groove angle, width, and depth exclusively. These measurements have been interpreted in terms of Mullins' 1957 theory on grain boundary grooving, which includes a derivation of the grain boundary groove profile. However, analyzing the groove depth, width, and angle uses only a small fraction of the groove profile information provided by Mullins' theory. In contrast to the literature, this study uses AFM data from thermal grooving in polycrystalline alumina to make a detailed comparison between Mullins' equation (and a modified form of Mullins' equation) for the entire groove profile rather than just the groove width or groove angle, thus providing a more rigorous and comprehensive test of theory. In addition, despite the wider and deeper grooves produced by microwave annealing, the modified form of Mullins' equation fits well both the microwave and conventionally annealed groove profiles.

Effects of annealing and film thickness on the electrical and optical properties of Sb:SnO2films deposited by electron beam from bulk samples prepared using sintering technique have beeninvestigated. A compromise between low resistivity and high transparency of the film has been studiedusing the factor of merit. This factor, which has been found maximum for film 100 nm thick annealed at 550 °C for 15 min, seemed to be enhanced with increasing annealing time and/or film thicknessconfirming the simultaneous improvements of transparency and conductance with the latters. Other opticaland electrical parameters such as refractive index, width of energy gap, density of localized states,concentration and mobility of carriers and Seebeck coefficient have been studied also, discussed andcorrelated to the microstructure changes with annealing and film thickness.

The X-ray diffracted intensity changes considerably when a static electric field is applied perpendicularly to a X- or Y-cut LiNbO3 platelet-shaped crystal. Section diffraction images (topographs) recorded using synchrotron radiation in transmission mode reveal the curvature of the lattice planes under such a field. A theoretical analysis based on the equations of electro-mechanical field in a piezoelectric medium together with chemical etching experiments allows us to explain this effect. Tiny inverted ferroelectric doMayns produced by the applied field exert a strain on the non-inverted bulk leading to the observed curvature of the lattice planes. This approach seems to be valid for other piezoelectric crystals of various symmetry classes.

Oxidation study, at 700 °C and under controlled atmosphere (oxygen partial pressure: 0.04 Pa) for 24 h, of unimplanted or yttrium implanted pure iron specimens was carried out using in situ X-ray diffraction to observe the yttrium implantation effect. In situ X-ray diffraction analyses performed on unimplanted pure iron clearly show the formation of FeO (wustite) and Fe3O4 (magnetite) compounds at the beginning of the oxidation test whereas the formation of Fe2O3 (hematite) is only detected after 1h30 of oxidation. In situ X-ray diffraction analyses performed with the same experimental conditions on yttrium implanted pure iron show the presence of two Mayn yttrium-iron mixed oxides (i.e. FeYO3 and Fe2YO4) in combination with wustite, magnetite and hematite structures. The presence of the Fe2YO4 compound is important because several authors have reported its anticorrosion properties at high temperature. X-ray diffraction results also show that the formation of FeYO3 and Fe2YO4 is Maynly reinforced at the gas-oxide interface which suggests an outward yttrium diffusion through the oxide layer from implanted pure iron.

The aim of this paper is to present the NH2 dielectric behaviour in theprimary amines for the importance it bears in the interaction of aminoacids andproteins and their influence in the electric conduction processes. For that, thedielectric properties of 1-propylamine, 1-butylamine and 1-pentylamine have beenstudied. Measurements were performed between room temperature and −180 °C inthe low frequency range and micro-waves measurements were done between −40 °Cand 25 °C. The isofrequency recordings of dispersion ε′ and absorption ε′′, for these three primary amines, showclearly the relaxations and the effect of the aliphatic chain length.

Measurements of the complex, frequency dependent susceptibility, χ(ω) = χ′ (ω) − i χ′′ (ω) over the frequency range 50 MHz to 15 GHz, of a surfacted ferrofluid comprising MnFe204 ferrite particles in dibutylphthalat (DBP), as a function of a biasing magnetic field arepresented. The biasing field was varied over the range 0 to 100 kAm−1, and has enabledaverage values of anisotropy constant, $\bar{K}$ , and anisotropy field $\bar{H}_{\rm A}$ forthe sample to be determined. Ferromagnetic resonance was exhibited for all values of the biasing field, covering the range 1.2 to 8.5 GHz, with the χ′ (ω) component of the susceptibility going negative in the GHz region.

Most plasma torches applied in modern thermal plasma processes can be ignited by a high voltage sparkoveror by a pilot arc because of the small distance between cathode and anode. The innovative plasma torchLARGE however is characterized by an arrangement of the electrodes opposite to each other on a common axiswith a variable distance up to some hundred millimeters. The central part of the torch between theelectrodes is divided into electrically insulated cascade plates. For industrial application of the torchLARGE a complete electronic ignition for high currents is substantial. A new semiconductor based method ofCombined Ignition by Pilot Arcing and Successive Switching (CIPASS) was developed. This ignition techniquewas investigated by electrical and optical diagnostics.

The question is, what happens when the bone loses its ability for load-driven adaptation, when damage is no longer repaired as it seems to be the case for bone loss associated with age, medication or disease? In this study, we tempt to show how damage can influence the remodeling process. A thermodynamic theoretical framework is therefore provided as a basis for a consistent formulation of bone remodeling involving a chemical reaction and mass transfer between two constituents in presence of microcracks.

A successful global vector field reconstruction from physiological signals is obtained for the first time. Data are generated by blood pressure and arterial diameter oscillations by using an arterial catheter with pressure transducer and an ultrasonic echo-tracking system, respectively. Results lead to the unambiguous evidence that such biological systems are characterized by a low-dimensional deterministic dynamical behavior. It is shown that a physiological system can be modelled from theknowledge of its behaviour only, as this has yet been done fortheoretical systems and for laboratory designed experiments.

The Sapphire Whispering Gallery Mode Resonatortechnology enables the design of microwave oscillators presentingexceptional short term frequency stability. The resonator consistsin a Al2O3 monocrystal disk where theelectro-magnetical field is efficiently confined thanks to aprocess analog to the optical total reflection. Due to the lowvalue of the sapphire dielectric losses, Q-factors as high as200000 at the ambient temperature and better than 10 millions at77 K is currently obtained. The sapphire resonator constitutes thenan ideal frequency reference that can be inserted in an oscillatorloop. At the Laboratoire de Physique et de Métrologie desOscillateurs, we implemented several sapphire resonatoroscillators operating at the ambient temperature and at 77 K. Weproposed original solutions to solve the Mayn difficulties arisingfrom the sapphire resonator, i.e. the large number of spuriousresonances and the large temperature sensitivity.

The equivalent series resistance of polypropylene capacitors has been determined under rated voltage, in the range 1 kHz–1 MHz, between 220 K and 370 K by a calorimetric technique. The original feature of this determination of capacitor losses lies in the use of the isothermal calorimetry and in the measurement of an electrical power and not of a temperature increase. The frequency dependence of the equivalent series resistance, at various temperatures, enables to separate the losses in the conducting material from those in the dielectric and to get their respective variations as a function of frequency and temperature. These variations of the equivalent series resistance with frequency at a given temperature have been reproduced by using an equivalent circuit composed of resistors, inductors and capacitors. This model has been verified for non-sinusoidal waveforms such as those met with in a filtering circuit and is used to evaluate by simulation the losses of the capacitor.