An automated steady state photocarrier grating experiment.

The design of an automated steady state photocarrier grating (SSPG) experiment is presented that matches most of the requirements of an industrial environment. We first briefly recall the bases of the SSPG technique and that the minority carrier diffusion length deduced from this experiment is a key parameter in the fabrication of thin film solar devices. We then underline the main drawbacks of the use of the classical SSPG technique as an industrial and systematic characterization technique mostly that all the adjustments have to be done manually.

Cytoglobin conformations and disulfide bond formation.

The oligomeric state and kinetics of ligand binding were measured for wild-type cytoglobin. Cytoglobin has the classical globin fold, with an extension at each extremity of about 20 residues. The extended length of cytoglobin leads to an ambiguous interpretation of its oligomeric state.

Heme ligand binding properties and intradimer interactions in the full-length sensor protein dos from Escherichia coli and its isolated heme domain.

Dos from Escherichia coli is a bacterial gas sensor protein comprising a heme-containing gas sensor domain and a phosphodiesterase catalytic domain. Using a combination of static light scattering and gel filtration experiments, we established that, as are many other sensor proteins, the full-length protein is dimeric. The full-length dimer (association constant <10 nm) is more stable than the dimeric heme domain (association constant approximately 1 mum), and the dimer interface presumably includes both sensor and catalytic domains.

Neuroglobin and prion cellular localization: investigation of a potential interaction.

Neuroglobin (Ngb) and the cellular prion protein (PrP(c)), proteins of unknown function in the nervous system, are known to be expressed in the retina and have been observed in different rat retinal cells. The retina is the site of the highest concentration for Ngb, a heme protein of similar size and conformation to myoglobin. In this study, we demonstrated by immunohistochemical analysis of retinal colocalization of Ngb and PrP(c) in the ganglion cell layer.

Characterization of defect levels in semi-insulating 6H-SiC by means of photoinduced transient spectroscopy and modulated photocurrent technique.

Parameters of electrically active defect centres in vanadium-doped 6H silicon carbide (6H-SiC:V) were investigated by means of the photoinduced transient spectroscopy (PITS) and modulated photocurrent (MPC) method. After a short description of the two techniques, experimental results are presented and briefly compared. Our aim is mainly to understand and explain these experimental results.

The influence of hopping on modulated photoconductivity.

We have developed equations taking into account both multiple-trapping and hopping processes for describing transport phenomena in disordered semiconductors. These equations have been introduced into a numerical simulation to model the steady state dark conductivity and photoconductivity as well as the modulated photoconductivity. The influence of parameters such as the density of states and attempt-to-hop frequency on the results of these experiments has been investigated.