Interactions between wear and corrosion on cast and sintered Ti-12Nb alloy in comparison with the commercial Ti-6Al-4V alloy

This work investigates the corrosion and tribocorrosion behavior of alpha + beta Ti-12Nb alloy processed by casting and sintering, in 9 g/l NaCl solution at body temperature, and compares the results with the commercial Ti-6Al-4 V alloy. Different electrochemical techniques were used to access the corrosion behavior. Tribocorrosion behavior was studied at open circuit potential under continuous and intermittent sliding, and at anodic potentiostatic condition under continuous sliding. Results revealed that Ti-12Nb alloys presented similar tribocorrosion behavior although the sintered one exhibited a better corrosion behavior. Nevertheless, Ti-6Al-4 V presented better overall degradation resistance than both Ti-12Nb alloys.- This work was supported by FCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020, together with M-ERA-NET/0001/2015, and co-supported by Brazilian agencies CNPq [grants #308.204/2017-4 and #125.954/2018-2] and FAPESP M-ERA-NET [grant #2015/50.280-5], also by MINECO (Spain) through the program PCIN-2016-123 and the Ramon y Cajal project RYC-2014-15014. I. Caha is grateful for a PhD grant under the NORTE-08-5369-FSE-000012 project

Dendrochronological dating of the historic McKenzie Home, Meigs County, Tennessee, USA

The McKenzie Home is a one-story log structure located in Meigs County, Tennessee. The land tract where the cabin was originally built was purchased by the McKenzie family ca. A.D. 1820 to 1828, which makes the suspected construction date for the home sometime after 1820. Our objective was to date oak (Quercus spp.) cross-sections taken from original logs to accurately determine the year when the trees were cut and therefore when the structure was built. We created a master chronology from measurements taken along 12 radii from five oak sections using program COFECHA to first confirm internal crossdating among the measured radii and then using program ARSTAN to create a floating master chronology. Interactive detrending identified two likely disturbances that affected tree growth on all five oaks and these trends were subsequently removed using 32-year splines. The McKenzie floating chronology was then compared with a composite reference chronology created from four oak chronologies located in Tennessee, Kentucky, and Alabama. An interseries correlation coefficient of 0.412 (n  =  169 years, t  =  5.84, p < 0.0001) was obtained between the floating chronology and the anchored reference chronology, indicating a single year of tree harvesting in A.D. 1876. Cutting dates for the five samples indicate harvesting began in the early part of the growing season in 1876 and lasted until the end of the growing season or possibly into the dormant season of 1876–1877. The graphical and statistical crossdating evidence and cutting dates that confirm 1876 as the year of construction matches historical property and district records, which state the land was purchased by E.G. McKenzie, Sr. from his brother on 1 February 1876. The log structure has since been renamed the “E.G. McKenzie, Sr. Home.”This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]

Method to disperse lipids as aggregates in oil for bilayers production

Several techniques to assemble artificial lipid bilayers involve the zipping of monolayers. Theirefficiency is determined by the renewal of the saturated monolayers to be zipped and this proceeds byadsorption of lipids dispersed in oil as aggregates. The size of these lipids aggregates is a key parameterto ensure both the stability of the suspension and a fast release of lipids at the interface. We proposea new method inspired from the solvent-shifting nucleation process allowing to control and tune thelipid aggregates size and that improves the production of artificial membranes. It is simpler and fasterthan current methods starting from a dry lipid film, which are highly sensitive to environmental conditions.This method opens the route to bilayer production processes with new potentialities in membranecomposition