The influence of climate on morphometric traits of fossil populations of Microtus arvalis and M. agrestis from the Carpathian Basin, northern Hungary

In this study, we analysed morphometrically fossil populations of Microtus arvalis and M. agrestis from eight late Middle to Late Pleistocene archaeological and palaeontological sites in the Carpathian Basin, northern Hungary. The intra- and interspecific variations in both species can be related to climatic oscillations linked to the onset of the Eemian interglacial and the first phases of Marine Isotope Stage 5. The size of M. agrestis can be correlated with the presence/absence of relatively humid climatic and environmental conditions and of surface water resources (such as marshes and flooded areas). A possible immigration event of M. arvalis populations into the Carpathian Basin, also related to the Eemian interglacial, is also identified.info:eu-repo/semantics/publishedVersio

Effect of Nb addition to Ti-bearing super martensitic stainless steel on control of Austenite grain size and strengthening

The role of Nb in normalized and tempered Ti-bearing 13Cr5Ni2Mo super martensitic stainless steel is investigated through in-depth characterization of the bimodal chemistry and size of Nb-rich precipitates/atomic clusters and Nb in solid solution. Transmission electron microscopy and atom probe tomography are used to analyze the samples and clarify precipitates/atom cluster interactions with dislocations and austenite grain boundaries. The effect of 0.1 wt pct Nb addition on the promotion of (Ti, Nb)N-Nb(C,N) composite precipitates, as well as the retention of Nb in solution after cooling to room temperature, are analyzed quantitatively. (Ti, Nb)N-Nb(C,N) composite precipitates with average diameters of approximately 24 ± 8 nm resulting from epitaxial growth of Nb(C,N) on pre-existing (Ti,Nb)N particles, with inter-particle spacing on the order of 205 ± 68 nm, are found to be associated with mean austenite grain size of 28 ± 10 µm in the sample normalized at 1323 K (1050 °C). The calculated Zener limiting austenite grain size of 38 ± 13 µm is in agreement with the experimentally observed austenite grain size distribution. 0.08 wt pct Nb is retained in the as-normalized condition, which is able to promote Nb(C, N) atomic clusters at dislocations during tempering at 873 K (600 °C) for 2 hours, and increases the yield strength by 160 MPa, which is predicted to be close to maximum increase in strengthening effect. Retention of solute Nb before tempering also leads to it preferentially combing with C and N to form Nb(C, N) atom clusters, which suppresses the occurrence of Cr- and Mo-rich carbides during tempering