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Macrofaunal species inhabiting intertidal mudflats and performing intense bioturbation are considered as ecosystem engineers, since they profoundly influence their physical, chemical, and biological environments. Nowadays, to complete our knowledge on the effect of bioturbation processes on the surrounding environment, interdisciplinary approach is essential to unravel their complex intertwined effects on intertidal mudflats. In this study, the effects of bioturbators on sediment properties, biogeochemical variables, and microbial dynamics (microphytobenthos, bacteria and archaea) were investigated. To this end, manipulation experiments were carried out in an intertidal mudflat of the Seine Estuary (France) by revamped the abundance of the two dominant bioturbators, Scrobicularia plana and Hediste diversicolor , in winter and late summer. Results showed that the presence of H. diversicolor in winter had a significant effect, with a significant increase in bed level accretion and microbial nitrate reduction rates. In contrast, the presence of S. plana showed no significant impact on sediment properties, most likely due to a reduced bioturbating activity at low temperature. In summer, both ecosystem engineers strongly influenced their surrounding environment but with opposite effects. The intense reworking of the sediment surface by S. plana limited microbial growth and enhanced erosion processes. Conversely, the presence of H. diversicolor favoured sediment accretion and enhanced microbial growth. Overall, this interdisciplinary study confirms the importance of these two ecosystem engineers in temperate estuarine mudflats by highlighting their simultaneous and intertwined effects on the sedimentary, physicochemical, and biological features. This confirms the importance of actively considering ecosystem engineers when restoring the natural habitats of tidal flats to cope with the different vulnerability risks related to global warming (sandification of estuarine sediments, disappearance of productive mudflats, sea level rise, vulnerability to storms and erosion). • Ecosystem engineers in mudflat simultaneously influence sediment properties, biogeochemical variables, and microbial dynamics • During winter, the bivalve species S. plana has minimal impact on the surrounding environment due to low temperature • During summer, the intense sediment reworking by S. plana limits biogeochemical and microbial processes • H. diversicolor enhances sediment stability, biogeochemistry, and microbial dynamics, via mucous secretion and bioirrigation [ABSTRACT FROM AUTHOR]

Sintered intermetallic Ag 3 Sn powders by spark plasma sintering (SPS) have been studied in order to analyse the effect of the microstructure on the transport properties at room temperature. Firstly, we synthesized Ag 3 Sn submicronic particles by polyol process. Then, we sintered them by SPS at different temperature (473, 573 and 663 K) and pressure (20 and 100 MPa) using fixed dwelling time of 5 min. X-Ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) show that all sintered samples remained single-phased according to the Ag 3 Sn orthorhombic crystal structure. Their corresponding grain size (≈ 0.65 to 1.75 μ m) and relative density (≈ 88–98%) were calculated and show similar evolution respect to the sintering parameters. As a matter of fact, sintering temperature remains the key factor to affect the microstructure of the sintered material s. Finally, the thermal conductivity and the electrical resistivity were investigated at room temperature by using the Flash Laser technique and the Physical Property Measurement System (PPMS) respectively. The obtained values were highly dependent on densitiy and grain showing the key role of the microstructure and thereby confirming the fact that Ag 3 Sn compound is a good candidate for a lead-free die-attach material in power module devices. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effects of the controlled change of a NiP surface roughness on both the wettability under ambient conditions and on pores formation in solder joints for specific soldering conditions have been studied. [•] Both the ability to minimize pores formation in solder joints and the wettability of the substrate decrease and become more variable when its roughness increases. [•] These effects can be explained considering the Cassie–Baxter model, completed by the model of heterogeneous nucleation and growth for gas bubbles inside a liquid. [Copyright &y& Elsevier]

Since 1998, routine [18F]FDG syntheses are being carried out by alkaline hydrolysis on a solid support, i.e. the labeled intermediate is trapped on a tC18 solid phase extraction cartridge, purified and finally hydrolyzed within the cartridge, at room temperature, using sodium hydroxide. The present study demonstrated that no epimerization of [18F]FDG to [18F]FDM occurs even when 12N NaOH is used and when the hydrolysis time is extended up to 1h. The alkaline hydrolysis on solid support appears to be a simple method leading to [18F]FDG with high purity. [Copyright &y& Elsevier]

Electroless Ni plating is widely used for its properties such as wear resistance, uniform coating and excellent brazing and solderability. In electronic and mechatronic applications, the chemical composition of the Ni layer and its surface quality still remains elusive and improvisation of Ni layer surface quality is vital. This research work investigates the surface properties of Ni films subjected to Ar-H 2 RF plasma treatment. Plasma treatment parameters are defined by utilizing D-Optimal design of experiments. A precise mapping of the evolution of Ni surface global chemical composition is obtained using an XPS. Principal component analysis on XPS mapping coupled with 3D ToF-SIMS chemical cartography enables precise identification of the different oxidation states of nickel and their distribution in the plasma-treated nickel samples. The nickel surface wettability is then determined using the classical sessile drop technique. The findings of the study enable to define the plasma optimal power and accomplish the best compromise between the positive effects of the surface decontamination and the negative effects of the surface recontamination. The optimized plasma treatment succeeds to modify the surface nature of the nickel from hydrophobic to strongly hydrophilic. It demonstrates that the Ar-H 2 plasma treatment is a very efficient process to increase the Ni surface wettability and thereby to improve the electronic and mechatronic assembly processes. • Nickel surface chemical composition, dependence on argon‑hydrogen plasma treatment settings is established. • Plasma-induced deoxidation efficiency passes through a maximum for a given power optimum value. • Optimum plasma treatment produces a soft argon ballistic effect which limits surface recontamination. • Optimized plasma treatment produces an efficient reduction of nickel hydroxide by hydrogen. • Optimized plasma treatment changes the nickel surface from hydrophobic to strongly hydrophilic. [ABSTRACT FROM AUTHOR]