Modelling of Microstructure Evolution during Thermoplastic Deformation of Steel by a Finite Element Method

A microstructure evolution model was coupled into finite element method to evaluate the dynamic recrystallization (DRX) and deformation behavior of low carbon steel under hot working. The flow stress curves and recrystallized grain size is measured from hot compression tests performed on Gleeble-1500. The recrystallization kinetics is expressed as Avrami equation calculated from measured flow stress curves including the effect of work hardening (WH), dynamic recovery (DRV)and DRX. Taking a hot compressed cylinder sample of Q235 as an example, an obvious non-uniform deformation is observed although the assumption of uniform deformation is commonly applied in this case. Microstructure evolution and macroscopic mechanical behavior of this sample were simulated and compared with measurements to examine the availability of the developed model

Surfactant-Free Emulsion Polymerization Stabilized by Ultrasmall Superparamagnetic Iron Oxide Particles Using Acrylic Acid or Methacrylic Acid as Auxiliary Comonomers

Iron oxide (IO)-based composite latex particles with a patchy IO overlayer were successfully prepared by Pickering emulsion polymerization of acrylic monomers and/or styrene using acrylic acid or methacrylic acid as auxiliary comonomers. The ultrasmall IO particles adsorbed at the latex surface and played the role of a solid stabilizer. The influence of the synthesis conditions on the composite particle size, polymerization kinetics, IO incorporation efficiency, and particle morphology was studied. Thermogravimetric analysis indicated that the efficiency of iron oxide incorporation was improved with increasing the suspension pH, the amount of auxiliary comonomer, or the IO content and reached ca. 90% under optimized conditions. Reducing the initial iron oxide concentration at constant monomer concentration led to an increased particle size and a reduced colloid stability, indicating that the magnetic nanoparticles stabilized the colloidal nanocomposites. Transmission electron microscopy studies confirmed the presence of iron oxide at the particle surface. In light of these results, a tentative mechanism for Pickering emulsion polymerization using IO nanoparticles as solid stabilizer in the presence of (meth)­acrylic acid auxiliary comonomers was proposed

Improving and Fining of Nanostructures by Mixing W with Mo in Metal Organic Hybrid Crystal

A bialloy-like multilayered bulk single crystal consisting of [(CH₃CH₂)₃NH)]₂­[W_0.25Mo_0.75O₂­(C₁₄H₆O₄)₂] has been synthesized, from which Mo–W-mixed organic hybrid nanotubes with a diameter of about 50 nm and length from tens to hundreds of nanometers were prepared by grinding and ultrasonication. The nanotubes possess the uniformity of Mo-based nanopipes and the rigidity of W-based nanotubules and are more delicate and standardized than W-based nanotubules and shorter than Mo-based nanopipes. Furthermore, the Mo–W-mixed nanotubes are disassembled into Mo-based nanowires with a diameter of about 5 nm and lengths in tens of nanometers and W-based nanoparticles with a diameter of 6 nm, which are much finer than the nanoarchitectures produced from Mo- and W-based crystal isomorphs. This research offers two new methods: one is the improvement of nanostructures in physical properties and morphologies by bialloy-like treatment, and another is the refinement of nanostructures compared with those made from crystal isomorphs based on one kind of metal, by mixing metals in a crystal lattice

Modélisation et ingénierie de la photosynthèse

La modélisation numérique a permis d'améliorer de nombreux procédés biotechnologiques à tous les niveaux (conception, optimisation, commande, supervision). C'est également le cas pour la culture des microalgues, où des efforts intenses sont aujourd'hui déployés pour développer des modèles de divers niveaux de complexité en fonction des objectifs et des dispositifs de production considérés (photobioréacteurs ou raceways), relevant cependant tous de l'ingénierie. Lorsqu'il s'agit de produire de la biomasse, le procédé est conduit de façon à ce que tous les éléments nutritifs soient maintenus à des concentrations optimales pour la croissance. Les deux principaux facteurs restants (éminemment variables dans le temps) agissant sur la croissance sont alors la lumière et la température dont les évolutions résultent du flux d'énergie solaire. Ce chapitre propose une revue des différents modèles physiques et biologiques existant, et présente les défis futur pour améliorer la modélisation de ces systèmes biotechnologiques émergeants

Additional file 4: Figure S4. of The administration of intranasal live attenuated influenza vaccine induces changes in the nasal microbiota and nasal epithelium gene expression profiles

Graphic representation of the relative abundance of Staphylococcus over time in subjects classified as having a low baseline level of Staphylococcus (i.e., below 10 %) at their first visit. The blue points represent the control group while the red points represent members of the LAIV group

Additional file 2: Figure S2. of The administration of intranasal live attenuated influenza vaccine induces changes in the nasal microbiota and nasal epithelium gene expression profiles

Ubiquity-ubiquity plot contrasting the ubiquities of a number of selected taxa, across a range of relative abundances between visits 1 and 2 in the control group as ascertained by hypervariable region V3–V5 sequencing. Only OTUs with a relative abundance greater than 0.5 % and change in ubiquity greater than 20 % were included in this plot. OTUs that aligned to the right of the diagonal were more ubiquitous during visit 1, while those to the left were more ubiquitous at visit 2

Expression and activation of the oxytocin receptor in airway smooth muscle cells: Regulation by TNFalpha and IL-13.

Background During pregnancy asthma may remain stable, improve or worsen. The factors underlying the deleterious effect of pregnancy on asthma remain unknown. Oxytocin is a neurohypophyseal protein that regulates a number of central and peripheral responses such as uterine contractions and milk ejection. Additional evidence suggests that oxytocin regulates inflammatory processes in other tissues given the ubiquitous expression of the oxytocin receptor. The purpose of this study was to define the role of oxytocin in modulating human airway smooth muscle (HASMCs) function in the presence and absence of IL-13 and TNFα, cytokines known to be important in asthma. Method Expression of oxytocin receptor in cultured HASMCs was performed by real time PCR and flow cytomery assays. Responses to oxytocin was assessed by fluorimetry to detect calcium signals while isolated tracheal rings and precision cut lung slices (PCLS) were used to measure contractile responses. Finally, ELISA was used to compare oxytocin levels in the bronchoalveloar lavage (BAL) samples from healthy subjects and those with asthma. Results PCR analysis demonstrates that OXTR is expressed in HASMCs under basal conditions and that both interleukin (IL)-13 and tumor necrosis factor (TNFα) stimulate a time-dependent increase in OXTR expression at 6 and 18 hr. Additionally, oxytocin increases cytosolic calcium levels in fura-2-loaded HASMCs that were enhanced in cells treated for 24 hr with IL-13. Interestingly, TNFα had little effect on oxytocin-induced calcium response despite increasing receptor expression. Using isolated murine tracheal rings and PCLS, oxytocin also promoted force generation and airway narrowing. Further, oxytocin levels are detectable in bronchoalveolar lavage (BAL) fluid derived from healthy subjects as well as from those with asthma. Conclusion Taken together, we show that cytokines modulate the expression of functional oxytocin receptors in HASMCs suggesting a potential role for inflammation-induced changes in oxytocin receptor signaling in the regulation of airway hyper-responsiveness in asthma