Influence of cutting process mechanics on surface integrity and electrochemical behavior of OFHC copper

The authors gratefully acknowledge the support received from IC ARTS and CEA ValducSuperfinishing machining has a particular impact on cutting mechanics, surface integrity and local electrochemical behavior. In fact, material removal during this process induces geometrical, mechanical and micro-structural modifications in the machined surface and sub-surface. However, a conventional 3D cutting process is still complex to study in terms of analytical/numerical modeling and experimental process monitoring. So, researchers are wondering if a less intricate configuration such as orthogonal cutting would be able to provide information about surface integrity as close as possible to that one generated by a 3D cutting process. For that reason, in the present paper, two different machining configurations were compared: face turning and orthogonal cutting. The work material is oxygen free high conductivity copper (OFHC) and the cutting tools are uncoated cemented carbide. The research work was performed in three steps. In the first step, the process mechanics of superfinishing machining of OFHC copper was performed. In the second step, the surface integrity and the chemical behavior of the machined samples were analyzed. Finally, in the third step, correlations between input parameters and output measures were conducted using statistical techniques. Results show that when applying low ratios between the uncut chip thickness and the cutting edge radius, the surface integrity and cutting energy are highly affected by the ploughing phenomenon. Otherwise, the most relevant cutting parameter is the feed. In order to compare face turning with orthogonal cutting, a new geometrical parameter was introduced, which has a strong effect in the electrochemical behavior of the machined surface

High Genetic Diversity and Clonal Growth in Relict Populations of Olea europaea subsp. laperrinei (Oleaceae) from Hoggar, Algeria

• Background and Aims The Laperrine's olive (Olea europaea subsp. laperrinei) is an endemic tree from Saharan massifs. Its populations have substantially regressed since the Pleistocene and are presently distributed in a fragmented habitat. Long-term persistence of this taxon is uncertain and programmes of preservation have to be urgently implemented. To define a conservation strategy, the genetic diversity and breeding system of this tree have to be investigated. • Methods One hundred and eleven ramets were prospected in the laperrinei populations from the Tamanrasset region, southern Algeria. Genetic polymorphism was revealed at nuclear and chloroplast DNA (cpDNA) microsatellite loci allowing a comparative assessment of the genetic diversity of laperrinei and Mediterranean populations based on bi-parental and maternal markers. Additionally, nuclear microsatellite markers enabled the genotypes to be identified unambiguously. • Key Results Based on nuclear microsatellite data, the total diversity was high (Ht = 0·61) in laperrinei populations and similar to that observed in western Mediterranean populations. A substantial cpDNA diversity (Ht = 0·19) was also observed. Genetically identical ramets originated from the same stump (which can cover >80 m2) were identified in each population. Sixteen per cent of genets exhibited more than one ramet. In addition, several cases of somatic mutations were unambiguously revealed in distinct ramets stemming from the same stump. • Conclusions These data show that highly isolated and small laperrinei populations are able to maintain a high genetic diversity. This supports the existence of relict trees persisting for a very long time (probably since the last humid transition, 3000 years ago). It is proposed that the very long persistence associated with an asexual multiplication of highly adapted trees could be a strategy of survival in extreme conditions avoiding a mutational meltdown due to reproduction in reduced population

Varietal Tracing of Virgin Olive Oils Based on Plastid DNA Variation Profiling

Olive oil traceability remains a challenge nowadays. DNA analysis is the preferred approach to an effective varietal identification, without any environmental influence. Specifically, olive organelle genomics is the most promising approach for setting up a suitable set of markers as they would not interfere with the pollinator variety DNA traces. Unfortunately, plastid DNA (cpDNA) variation of the cultivated olive has been reported to be low. This feature could be a limitation for the use of cpDNA polymorphisms in forensic analyses or oil traceability, but rare cpDNA haplotypes may be useful as they can help to efficiently discriminate some varieties. Recently, the sequencing of olive plastid genomes has allowed the generation of novel markers. In this study, the performance of cpDNA markers on olive oil matrices, and their applicability on commercial Protected Designation of Origin (PDO) oils were assessed. By using a combination of nine plastid loci (including multi-state microsatellites and short indels), it is possible to fingerprint six haplotypes (in 17 Spanish olive varieties), which can discriminate high-value commercialized cultivars with PDO. In particular, a rare haplotype was detected in genotypes used to produce a regional high-value commercial oil. We conclude that plastid haplotypes can help oil traceability in commercial PDO oils and set up an experimental methodology suitable for organelle polymorphism detection in the complex olive oil matrices

Pouring CREAM into natural gas: The introduction of Common Performance Conditions into the safety management of gas networks

International audienceLearning from operational experience is a process that has arisen as a result of the need in industry to manage the increasing complexity of technical systems. While dependability was initially dominant, limitations in its ability to account for human variability have gradually become apparent. The use of the human and organisational factors paradigm emerged in an attempt to overcome these limitations, and learning from operational experience has evolved out of this. This evolution led to a shift of interest towards the influence of the work environment on human performance. The CREAM method, structured by the Common Performance Conditions (CPCs), is a major example of this trend. This paper discusses the design and deployment of an accident analysis grid developed in 2008 by a major French gas distribution company. This grid was a response to the company's decision to revitalise the learning from operational experience process through the use of human and organisational factors

Accidents in the gas distribution industry. Some consequences of the introduction of new analysis criteria

International audienceThe learning from experience process is necessitated by the growing complexity of industrial technical systems. The formerly dominant dependability paradigm has gradually shown its limits in the understanding of human performance. The paradigm of human and organizational factors attempts to remedy this, and is the basis for a new accident analysis grid implemented in a large French gas distribution company. This paper is a description of the technical contents of the grid and an account of the various changes that were introduced in the company. Beyond the implementation of the grid culture and practices have changed that make the effect on safety less easy to characterize than one might expect

Genomic profiling of plastid DNA variation in the Mediterranean olive tree

<p>Abstract</p> <p>Background</p> <p>Characterisation of plastid genome (or cpDNA) polymorphisms is commonly used for phylogeographic, population genetic and forensic analyses in plants, but detecting cpDNA variation is sometimes challenging, limiting the applications of such an approach. In the present study, we screened cpDNA polymorphism in the olive tree (<it>Olea europaea </it>L.) by sequencing the complete plastid genome of trees with a distinct cpDNA lineage. Our objective was to develop new markers for a rapid genomic profiling (by Multiplex PCRs) of cpDNA haplotypes in the Mediterranean olive tree.</p> <p>Results</p> <p>Eight complete cpDNA genomes of <it>Olea </it>were sequenced <it>de novo</it>. The nucleotide divergence between olive cpDNA lineages was low and not exceeding 0.07%. Based on these sequences, markers were developed for studying two single nucleotide substitutions and length polymorphism of 62 regions (with variable microsatellite motifs or other indels). They were then used to genotype the cpDNA variation in cultivated and wild Mediterranean olive trees (315 individuals). Forty polymorphic loci were detected on this sample, allowing the distinction of 22 haplotypes belonging to the three Mediterranean cpDNA lineages known as E1, E2 and E3. The discriminating power of cpDNA variation was particularly low for the cultivated olive tree with one predominating haplotype, but more diversity was detected in wild populations.</p> <p>Conclusions</p> <p>We propose a method for a rapid characterisation of the Mediterranean olive germplasm. The low variation in the cultivated olive tree indicated that the utility of cpDNA variation for forensic analyses is limited to rare haplotypes. In contrast, the high cpDNA variation in wild populations demonstrated that our markers may be useful for phylogeographic and populations genetic studies in <it>O. europaea</it>.</p

De l'utilisation du modèle cream et des "conditions communes de la performance" pour la conduite du retour d'expérience. Application à la sécurité de la distribution du gaz

Le retour d'expérience est un processus qui se justifie par la nécessité de maîtriser la complexité grandissante des systèmes techniques industriels. D'abord dominante, la sûreté de fonctionnement a peu à peu montré ses limites dans la prise en compte de la variabilité humaine. L'émergence du paradigme des facteurs humain et organisationnel tentant d'y remédier, le retour d'expérience a évolué. L'outil OCEANIE développé depuis 2008 par GrDF répond à ce choix de renouveler le retour d'expérience au moyen des facteurs humain et organisationnel

Bretteville-l'Orgueilleuse – Prospection géophysique sur la villa gallo-romaine

Lien Atlas (MCC) :http://atlas.patrimoines.culture.fr/atlas/trunk/index.php?ap_theme=DOM_2.01.02&ap_bbox=-0.546;49.201;-0.493;49.228 Une prospection géophysique par méthode radar a été menée sur la pars urbana en périphérie de la fouille de Bretteville-l’Orgueilleuse, le Bas des Prés. Celle-ci avait déjà fait l’objet d’une prospection par méthode électrique à l’automne 2012, méthode qui avait permis de dresser un plan particulièrement complet de l’ensemble. L’étude réalisée en 2013 avait pour..

Bretteville-l’Orgueilleuse – Villa gallo-romaine

Une prospection géophysique par méthode électrique a été réalisée en périphérie de la fouille de Bretteville-l’Orgueilleuse « Le Bas des Prés ». Étant donné que cette fouille n’a abordé que la périphérie d’un important domaine antique, la démarche avait pour objectif de compléter le plan de la pars urbana et de cartographier le mieux possible les restes bâtis de la résidence principale, jusqu’alors partiellement connue à partir d’une photo aérienne et de sondages mécaniques. La prospection él..

Phylogenetics of Olea (Oleaceae) based on plastid and nuclear ribosomal DNA sequences: Tertiary climatic shifts and lineage differentiation times

Background and Aims The genus Olea (Oleaceae) includes approx. 40 taxa of evergreen shrubs and trees classified in three subgenera, Olea, Paniculatae and Tetrapilus, the first of which has two sections (Olea and Ligustroides). Olive trees (the O. europaea complex) have been the subject of intensive research, whereas little is known about the phylogenetic relationships among the other species. To clarify the biogeographical history of this group, a molecular analysis of Olea and related genera of Oleaceae is thus necessary. Methods A phylogeny was built of Olea and related genera based on sequences of the nuclear ribosomal internal transcribed spacer-1 and four plastid regions. Lineage divergence and the evolution of abaxial peltate scales, the latter character linked to drought adaptation, were dated using a Bayesian method. Key Results Olea is polyphyletic, with O. ambrensis and subgenus Tetrapilus not sharing a most recent common ancestor with the main Olea clade. Partial incongruence between nuclear and plastid phylogenetic reconstructions suggests a reticulation process in the evolution of subgenus Olea. Estimates of divergence times for major groups of Olea during the Tertiary were obtained. Conclusions This study indicates the necessity of revising current taxonomic boundaries in Olea. The results also suggest that main lines of evolution were promoted by major Tertiary climatic shifts: (1) the split between subgenera Olea and Paniculatae appears to have taken place at the Miocene-Oligocene boundary; (2) the separation of sections Ligustroides and Olea may have occurred during the Early Miocene following the Mi-1 glaciation; and (3) the diversification within these sections (and the origin of dense abaxial indumentum in section Olea) was concomitant with the aridification of Africa in the Late Miocen