Evaluating the RCCI operating range limits in a high compression ratio medium-duty diesel engine fueled with biodiesel and ethanol

[EN] This work investigates the load limits of reactivity controlled compression ignition combustion, a dual-fuel concept which combines port fuel injection of low-reactivity fuels with direct injection of diesel fuel, in a medium-duty diesel engine. The experiments were conducted in a single-cylinder diesel engine derived from the multi-cylinder production engine. In this sense, the stock turbocharger and exhaust gas recirculation systems were replaced by an external compressor and dedicated low-pressure exhaust gas recirculation loop, respectively. Additionally, a port fuel injector was installed in the intake manifold to allow gasoline injection. First, this article presents some results highlighting the effect of the exhaust gas recirculation rate, gasoline fraction, diesel start of injection, diesel injection strategy and intake temperature on the emissions, performance and combustion development in a representative operating condition: 1200r/min and 6.5bar indicated mean effective pressure (25% load). Later, with the aim of showing the reactivity controlled compression ignition potential, the best results in terms of performance and emissions at 25% load are compared against the multi-cylinder diesel engine from 950 to 2200r/min. Reactivity controlled compression ignition engine tests were developed taking into account limitations in nitrogen oxides (NOx) and soot emissions, in-cylinder pressure and maximum pressure rise rate. Finally, keeping the same constraints for testing, the load limits of reactivity controlled compression ignition concept are evaluated for all the engine speeds. Results suggest that reactivity controlled compression ignition allows fulfilling EURO VI limits for NOx and soot emissions without using selective catalytic reduction and diesel particulate filter aftertreatment systems at 25% load at all the engines speeds, providing better indicated efficiency than conventional diesel operation in most operating points. In addition, the maximum engine load that ensured the aforementioned constraints was around 35% for all the engine speeds, with a maximum indicated mean effective pressure of 8.8bar at 2200r/min. In this case, a strong reduction in carbon monoxide (CO) and unburned hydrocarbon (HC) emissions compared to the cases of 25% load was achieved at all the engine speeds.Benajes, J.; García Martínez, A.; Monsalve-Serrano, J.; Balloul, I.; Pradel, G. (2017). Evaluating the RCCI operating range limits in a high compression ratio medium-duty diesel engine fueled with biodiesel and ethanol. 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Evidence for an uncommon alpha-actinin protein in Trichomonas vaginalis.

International audienceAs part of our ongoing project of identification of actin-binding proteins implicated in the cell transition (flagellate to amoeboid/adherent) of Trichomonas vaginalis, we have characterized an alpha-actinin-related protein in this parasite. The protein (P100) has a molecular mass of 100 kDa and an isoelectric point of 5.5. A monoclonal antibody raised against this protein co-localizes with the actin network. P100 gene transcripts are co-expressed with actin throughout the cell cycle. Analysis of the deduced protein sequence reveals three domains: an N-terminal actin-binding region; a central region rich in alpha-helix; and a C-terminal domain with Ca(2+)-binding capacity. Whereas the N- and C-terminal regions are well-conserved as compared to other alpha-actinins, we observe in the central region an atypical distribution of residues in five repeats. The sequence of the repeats does not show any homology with the rod domain of the other alpha-actinins, except for the first repeat which shows some similarity. The four other repeats of T. vaginalis P100 appear to result from a duplication event which is not detectable in the other sequences

The membrane skeleton in Paramecium: Molecular characterization of a novel epiplasmin family and preliminary GFP expression results.

International audiencePrevious attempts to identify the membrane skeleton of Paramecium cells have revealed a protein pattern that is both complex and specific. The most prominent structural elements, epiplasmic scales, are centered around ciliary units and are closely apposed to the cytoplasmic side of the inner alveolar membrane. We sought to characterize epiplasmic scale proteins (epiplasmins) at the molecular level. PCR approaches enabled the cloning and sequencing of two closely related genes by amplifications of sequences from a macronuclear genomic library. Using these two genes (EPI-1 and EPI-2), we have contributed to the annotation of the Paramecium tetraurelia macronuclear genome and identified 39 additional (paralogous) sequences. Two orthologous sequences were found in the Tetrahymena thermophila genome. Structural analysis of the 43 sequences indicates that the hallmark of this new multigenic family is a 79 aa domain flanked by two Q-, P- and V-rich stretches of sequence that are much more variable in amino-acid composition. Such features clearly distinguish members of the multigenic family from epiplasmic proteins previously sequenced in other ciliates. The expression of Green Fluorescent Protein (GFP)-tagged epiplasmin showed significant labeling of epiplasmic scales as well as oral structures. We expect that the GFP construct described herein will prove to be a useful tool for comparative subcellular localization of different putative epiplasmins in Paramecium

Putative membrane assembly of EtpM-colicin V chimeras

International audienc

Utilisation de la radiothermoluminescence de l'alumine pour la dosimétrie de zone

Des tuiles contenant du quartz et du feldspath ont été utilisées pour la dosimétrie des rayonnements gamma émis lors des explosions d’Hiroshima et de Nagasaki. Cette méthode pourrait faire l’objet d’autres applications, notamment pour la dosimétrie des accidents de criticité. Nous avons pensé qu’il serait préférable d’inclure systématiquement, dans les constructions, des briques contenant une forte proportion d’un matériau dosimétrique radiothermoluminescent. Nos études nous ont amenés à sélectionner une qualité industrielle d’oxyde d’aluminium disponible sur le marché à un prix avantageux. Dans ce texte, nous analysons les caractéristiques cristallographiques et chimiques de ce matériau en liaison avec ses propriétés radiothermoluminescentes. Il présente une courbe de thermoluminescence à quatre niveaux d’énergie; on n’utilise que les plus profonds. Avec un matériel de lecture ordinaire on peut faire des mesures de 0,5 à 106 rads. Ce matériau est très peu sensible aux neutrons, ce qui permet de l’utiliser dans les champs mixtes. A titre d’exemple, nous donnons les résultats de la dosimétrie réalisée à l’aide de briques d’alumine lors des essais nucléaires français du Pacifique

Etude du lien entre terroir et produit dans le cas des fromages et des vins

National audienc

Use of intravenous immunoglobulins in clinical practice: data from three French university hospitals

International audienceSince several years, the use of intravenous immunoglobulins (IVIg) has increased. This growth has encouraged some countries to publish guidelines. In parallel, some countries have conducted audits to know how IVIg are used in clinical practice in the light of the available guidelines. The objective of this study was to assess IVIg use in three French university hospitals in 2006. All IVIg administrations were evaluated during 6 months (12 September 2005-12 March 2006) in French university hospitals of Marseille. Different data were recorded for each administration: patient characteristics, indication, formulation and quantity. During the study period, 2802 administrations of IVIg (corresponding to a total quantity of 76 780 g) have been recorded. Four hundred and thirty-five patients received at least one of these administrations. The five most reported indications were multifocal motor neuropathy (11.0% of total quantity), chronic inflammatory demyelinating polyradiculoneuropathy (10.2%), corticoresistant dermatomyositis (10.2%), immune thrombocytopaenia (9.9%) and primary immune deficiency (9.1%). According to available French recommendations, 70% of the IVIg use was for 'acknowledged indications', 9% for 'indications to be assessed' and 18% for 'unwarranted indications'. Th