Mass transfer and hydrodynamic characteristics of new carbon carbon packing: Application to CO2 post-combustion capture

A novel structured packing, the 4D packing, has been characterized in terms of hydrodynamics, effective area and gas side mass transfer coefficient. The increase of the 4D opening fraction allows to reduce pressure drop and to get a better capacity than Mellapak 500Y and 750Y, for which the geometric areas are similar. The 50% open 4D packing, 4D-50%, leads to effective areas which are higher than Mellapak 500Y ones, and doubled compared with Mellapak Plus 252Y ones. Effective areas for the 4D do not decrease when the opening fraction increases from 30 to 50%, this indicates that a non-negligible amount of droplets is generated at 50%. Gas side mass transfer coefficient had been measured with an original experimental method: water evaporation. Corresponding results seem to be in agreement with the literature, and with the fact that a large amount of droplets is generated. Correlations are proposed for both effective area and gas side mass transfer coefficient for the 4D-50%.The 4D-50% packing could be very interesting for post-combustion CO2 capture since it generates low pressure drop and a very high interfacial area. This will be further confirmed by an economic study for which the absorber plant will be designed with a rate based model

Loss of containment: Experimental validation of initially subcooled two phase critical flow models

International audienceA new setup allows us to experiment initially subcooled two-phase critical flows with five different fluids: water, R11, methanol ethyl acetate and butane. We verify that good estimates of the mass flow rate can be derived from the extended HEM for all of the fluids in high subcooling conditions (within ± 20% accuracy). In low subcooling conditions, a satisfactory agreement (± 30% accuracy) with the DEM or HEM predictions is found. This means that the main phenomena involved seem to be correctly taken into account

Le rabais britannique et la révision de la PAC. Vers la fin de la solidarité financière ?

Lors des discussions budgétaires 2007-2013, la remise en cause du rabais britannique fut conditionnée par le RU à une refonte de la PAC. Episode de l’opposition classique de conceptions, c’est aussi l’amorce d’un sérieux réexamen de la PAC, de son coût budgétaire et du principe de solidarité financière. Les auteurs montrent que l’exception britannique ne se justifie plus par son solde net actuel, mais ils proposent aussi de remplacer le principe de solidarité, source d’échec de la décision publique, par celui de responsabilité financière : le cofinancement de toute les dépenses la PAC par les Etats qui en bénéficient.During the discussions of the 2007-2013 budget the UK conditioned the renegotiation of the rebate upon a deep reform of CAP. More than a new episode of a classic internal struggle, it launches a process of re-examination of the CAP, of its budgetary outlays and of the financial solidarity principle. The article shows that the UK exception is no longer justified by its net financial balance due to the CAP, but it also argues in favour of substituting the financial solidarity principle which entails political failures for a “responsibility principle” i.e., the co-financing of all CAP expenditures by benefiting Member States

Numerical method for three-dimensional macroscale simulations of two-phase flows with moving contact lines

Un modèle d'angle de contact dynamique est développé avec une méthode level-set pour simuler des écoulements macroscopiques tridimensionnels avec lignes de contact mobiles. Le code est validé à partir de simulations numériques directes et résultats expérimentaux d'étalement de gouttelette en régimes visqueux et inertiel. Le code permet de simuler des écoulements tridimensionnels avec ligne de contact mobile en tenant compte de l'hystérésis de l'angle de contact

Healthy knee kinematic phenotypes identification based on a clustering data analysis

The purpose of this study is to identify healthy phenotypes in knee kinematics based on clustering data analysis. Our analysis uses the 3D knee kinematics curves, namely, flexion/extension, abduction/adduction, and tibial internal/external rotation, measured via a KneeKG™ system during a gait task. We investigated two data representation approaches that are based on the joint analysis of the three dimensions. The first is a global approach that is considered a concatenation of the kinematic data without any dimensionality reduction. The second is a local approach that is considered a set of 69 biomechanical parameters of interest extracted from the 3D kinematic curves. The data representations are followed by a clustering process, based on the BIRCH (balanced iterative reducing and clustering using hierarchies) discriminant model, to separate 3D knee kinematics into homogeneous groups or clusters. Phenotypes were obtained by averaging those groups. We validated the clusters using inter-cluster correlation and statistical hypothesis tests. The simulation results showed that the global approach is more efficient, and it allows the identification of three descriptive 3D kinematic phenotypes within a healthy knee population

Establishment of an in vitro chicken epithelial cell line model to investigate Eimeria tenella gamete development

Background: Eimeria tenella infection leads to acute intestinal disorders responsible for important economic losses in poultry farming worldwide. The life-cycle of E. tenella is monoxenous with the chicken as the exclusive host; infection occurs in caecal epithelial cells. However, in vitro, the complete life-cycle of the parasite has only been propagated successfully in primary chicken kidney cells, which comprise undefined mixed cell populations; no cell line model has been able to consistently support the development of the sexual stages of the parasite. We therefore sought to develop a new model to study E. tenella gametogony in vitro using a recently characterised chicken cell line (CLEC-213) exhibiting an epithelial cell phenotype. Methods: CLEC-213 were infected with sporozoites from a precocious strain or with second generation merozoites (merozoites II) from wild type strains. Sexual stages of the parasite were determined both at the gene and protein levels. Results: To our knowledge, we show for the first time in CLEC-213, that sporozoites from a precocious strain of E. tenella were able to develop to gametes, as verified by measuring gene expression and by using antibodies to a microgamete-specific protein (EtFOA1: flagellar outer arm protein 1) and a macrogamete-specific protein (EtGAM-56), but oocysts were not observed. However, both gametes and oocysts were observed when cells were infected with merozoites II from wild type strains, demonstrating that completion of the final steps of the parasite cycle is possible in CLEC-213 cells. Conclusion: The epithelial cell line CLEC-213 constitutes a useful avian tool for studying Eimeria epithelial cell interactions and the effect of drugs on E. tenella invasion, merogony and gametogony.This work was supported by INRA

8-Aryl-6-chloro-3-nitro-2-(phenylsulfonylmethyl)imidazo[1,2-a]pyridines as potent antitrypanosomatid molecules bioactivated by type 1 nitroreductases

Based on a previously identified antileishmanial 6,8-dibromo-3-nitroimidazo[1,2-a]pyridine derivative, a Suzuki-Miyaura coupling reaction at position 8 of the scaffold was studied and optimized from a 8-bromo-6-chloro-3-nitroimidazo[1,2-a]pyridine substrate. Twenty-one original derivatives were prepared, screened in vitro for activity against L infantum axenic amastigotes and T. brucei brucei trypomastigotes and evaluated for their cytotoxicity on the HepG2 human cell line. Thus, 7 antileishmanial hit compounds were identified, displaying IC50 values in the 1.1-3 mu M range. Compounds 13 and 23, the 2 most selective molecules (SI = >18 or >17) were additionally tested on both the promastigote and intramacrophage amastigote stages of L donovani. The two molecules presented a good activity (IC50 = 1.2-1.3 mu M) on the promastigote stage but only molecule 23, bearing a 4-pyridinyl substituent at position 8, was active on the intracellular amastigote stage, with a good IC50 value (2.3 mu M), slightly lower than the one of miltefosine (IC50 = 4.3 mu M). The antiparasitic screening also revealed 8 antitrypanosomal hit compounds, including 14 and 20, 2 very active (IC50 = 0.04-0.16 mu M) and selective (SI = >313 to 550) molecules toward T brucei brucei, in comparison with drug-candidate fexinidazole (IC50 = 0.6 & SI > 333) or reference drugs suramin and eflornithine (respective IC50 = 0.03 and 13.3 mu M). Introducing an aryl moiety at position 8 of the scaffold quite significantly increased the antitrypanosomal activity of the pharmacophore. Antikinetoplastid molecules 13, 14, 20 and 23 were assessed for bioactivation by parasitic nitroreductases (either in L donovani or in T. brucei brucei), using genetically modified parasite strains that over-express NTRs: all these molecules are substrates of type 1 nitroreductases (NTRI), such as those that are responsible for the bioactivation of fexinidazole. Reduction potentials measured for these 4 hit compounds were higher than that of fexinidazole (-0.83 V), ranging from -0.70 to -0.64 V

Bypass and hyperbole in soil science:A perspective from the next generation of soil scientists

International audienceWe, the co‐authors of this letter, are an international group of soil scientists at early career stages, from PhD students to postdoctoral researchers, lecturers, and research fellows with permanent positions. Here, we present our collective musings on soil research challenges and opportunities and, in particular, the points raised by Philippe Baveye (Baveye, 2020a, 2020b) and Johan Bouma (Bouma, 2020) on bypass and hyperbole in soil science. Raising awareness about these issues is a first and necessary step. To this end, we would like to thank Philippe Baveye and Johan Bouma for initiating this debate.......

Nongenotoxic 3-Nitroimidazo[1,2-a]pyridines Are NTR1 Substrates That Display Potent in Vitro Antileishmanial Activity

Twenty nine original 3-nitroimidazo[1,2-a]pyridine derivatives, bearing a phenylthio (or benzylthio) moiety at position 8 of the scaffold, were synthesized. In vitro evaluation highlighted compound 5 as an antiparasitic hit molecule displaying low cytotoxicity for the human HepG2 cell line (CC50 > 100 mu M) alongside good antileishmanial activities (IC50 = 1-2.1 mu M) against L. donovani, L. infantum, and L. major; and good antitrypanosomal activities (IC50 = 1.3-2.2 mu M) against T. brucei brucei and T. cruzi, in comparison to several reference drugs such as miltefosine, fexinidazole, eflornithine, and benznidazole (IC50 = 0.6 to 13.3 mu M). Molecule 5, presenting a low reduction potential (E degrees = -0.63 V), was shown to be selectively bioactivated by the L. donovani type 1 nitroreductase (NTR1). Importantly, molecule 5 was neither mutagenic (negative Ames test), nor genotoxic (negative comet assay), in contrast to many other nitroaromatics. Molecule 5 showed poor microsomal stability; however, its main metabolite (sulfoxide) remained both active and nonmutagenic, making 5 a good candidate for further in vivo studies

Truncated mass divergence in a Mott metal

The Mott metal–insulator transition represents one of the most fundamental phenomena in condensed matter physics. Yet, basic tenets of the canonical Brinkman-Rice picture of Mott localization remain to be tested experimentally by quantum oscillation measurements that directly probe the quasiparticle Fermi surface and effective mass. By extending this technique to high pressure, we have examined the metallic state on the threshold of Mott localization in clean, undoped crystals of NiS2. We find that i) on approaching Mott localization, the quasiparticle mass is strongly enhanced, whereas the Fermi surface remains essentially unchanged; ii) the quasiparticle mass closely follows the divergent form predicted theoretically, establishing charge carrier slowdown as the driver for the metal–insulator transition; iii) this mass divergence is truncated by the metal–insulator transition, placing the Mott critical point inside the insulating section of the phase diagram. The inaccessibility of the Mott critical point in NiS2 parallels findings at the threshold of ferromagnetism in clean metallic systems, in which criticality at low temperature is almost universally interrupted by first-order transitions or novel emergent phases such as incommensurate magnetic order or unconventional superconductivity