Interfacial adhesion characterization of plasma coatings by V(z) inversion technique and comparison to interfacial indentation

This paper presents the development of V(z) inversion technique and its application to quantitative determination of interface adhesion by measuring interface tangential stiffness parameter K_T. The measurement is performed in two steps on an air plasma sprayed bronze-aluminum alloy coating (on a steel substrate) having different adhesion levels: the determination of the coating elastic constants and the determination of the interface tangential stiffness K_T are performed by optimizing the inverted angular-frequency reflectance function R(θ,f). The results obtained by the V(z) inversion are then compared to mechanical testing by interfacial indentation on the same sample. The same behavior (quality of interface adhesion) can be seen by both methods: the coating adhesion decreases as the interfacial stiffness parameter K_T decreases.     

Development of an innovative, two-processor data processing unitfor the magnetospheric imaging instrument onboard the Cassini mission toSaturn. I. Hardware architecture

This paper presents an innovative two-processor computer architecture, developed for the data processing unit (DPU) of the Magnetospheric IMaging Instrument (MIMI), on-board the Cassini spacecraft mission to Saturn. The main advantages of this architecture are its high performance and reliability, and its intelligence. The high performance is justified by the following: 1) optimum combination of two powerful Harris RTX 2010 processors; 2) adoption of two independent main bus structures used for the communication of the processors with the various instrument interfaces and subsystems; 3) adoption of two additional local buses on each processor board used to speed the on-board operations of the processors; 4) high speed interprocessor communication port. The high reliability is justified by the following: 1) simplicity of hardware/software structures; 2) fault tolerance capabilities; 3) capability for on-flight hardware/software reconfiguration by ground command. Moreover, the on-board intelligence is justified by the following: 1) sophisticated fault protection, data handling, and instrument control software; 2) intelligent interfaces [implemented using held programmable gate arrays (FPGAs)]; 3) capability for autonomous on-flight hardware/software reconfiguration in case of an unrecoverable failure in one processor. The advantages of this architecture make it the best choice for the DPU of the complex, sophisticated scientific MIMI instrument, compared to the traditional master-slave (low reliability-single point failure) and common shared bus (low performance, hardware and software complexity) architectures     

II. Yeast sequencing reports. Sequence analysis of a 31 kb DNA fragment from the right arm of Saccharomyces cerevisiae chromosome II

The nucleotide sequence of a 31 352 bp fragment from chromosome II of Saccharomyces cerevisiae has been determined and analysed. The fragment originates from the right arm of chromosome II, located between the GAL7,10,1 and the PHO3,5 loci, at a distance of about 130 kb from the centromere. The sequence contains a tRNA tandem repeat and 17 open reading frames (ORFs) larger than 100 amino acids. One of them extends into adjacent DNA and is incomplete. The two tRNA genes, coding for a tRNA^asp and a tRNA^arg, and three of the ORFs, had been sequenced previously, i.e. HSP26, SEC18, and UBC4. Four other ORFs showed similarity with yeast genes; amino acid transporter genes, the RAD54, SNF2 and STH1 family, the SPS2 gene and the bromodomain of SPT7, respectively. Two showed homology with sequences from other organisms, i.e. with a Plasmodium falciparum gene encoding a surface antigen and with a gene from Saimirine herpes virus respectively. Three ORFs, YBR0726, YBR0735 and YBR0740 are completely contained in YBR0727, YBR0734 and YBR0739 respectively, and thus probably do not represent real genes. Two ORFs, YBR0727 and YBR0745 most likely contain an intron. The sequences have been deposited in the EMBL data library under Accession Number X76294.     

Influence of Irradiation on the Oxide Film Formed on 316 L Stainless Steel in PWR Primary Water

Oxidation of stainless steel in PWR primary water at 325 °C was studied by investigating the influence of defects created at the alloy subsurface by proton irradiation before corrosion exposure. Corrosion experiments were conducted by sequentially exposing samples, with H ₂ ¹⁸ O used for the second exposure. The oxide layer, formed in these conditions was studied by SEM and TEM and could be divided in two parts: an external discontinuous layer composed of crystallites rich in iron and an internal continuous layer richer in chromium. Tracer experiments revealed that the growth of this protective scale was due to oxygen diffusion in the grain boundary of the oxide layer. Defects created by irradiation have an effect on the two oxide layers. They are a preferential nucleation site for the external layer and so increase the density of the crystallites. They also induce a slower diffusion of oxygen in the internal layer.     

Multichannel dosemeter and Al2O3:C optically stimulated luminescence fibre sensors for use in radiation therapy: evaluation with electron beams

This article proposes an innovative multichannel optically stimulated luminescence (OSL) dosemeter for on-line in vivo dose verification in radiation therapy. OSL fibre sensors incorporating small Al(2)O(3):C fibre crystals (TLD(500)) have been tested with an X-ray generator. A reproducible readout procedure should reduce the fading-induced uncertainty ( approximately - 1% per decade). OSL readouts are temperature-dependent [ approximately 0.3% K(-1) when OSL stimulation is performed at the same temperature as irradiation; approximately 0.16% K(-1) after thermalisation (20 degrees C)]. Sensor calibration and depth-dose measurements with electron beams have been performed with a Saturne 43 linear accelerator in reference conditions at CEA-LNHB (ionising radiation reference laboratory in France). Predosed OSL sensors show a good repeatability in multichannel operation and independence versus electron energy in the range (9, 18 MeV). The difference between absorbed doses measured by OSL and an ionisation chamber were within +/-0.9% (for a dose of about 1 Gy) despite a sublinear calibration curve.