Germanium films were grown on c-plane sapphire with a 10 nm AlAs buffer layer using molecular beam epitaxy. The effects of Ge film thickness on the surface morphology and crystal structure were investigated by ex-situ characterization techniques. The nucleation of Ge proceeds by forming (111) oriented three-dimensional islands with two rotational twin domains about the growth axis. The boundaries between the twin grains are the origin of 0.2% strain and tilt grains. The transition to a single-grain orientation reduces the strain and results in a better-quality Ge buffer. Understanding the role of thickness on material quality during the Ge(111)/Al2O3(0001) epitaxy is vital for achieving device quality when using group IV material on the sapphire platform.

In this work, plastic deformation was locally introduced at room temperature by nanoindentation on a γ-TiAl based alloy. Comprehensive analyzes of microstructures were performed before and after deformation. In particular, the Burgers vectors, the line directions and the mechanical twinning systems were studied via accurate electron channeling contrast imaging. Accommodation of the deformation are reported and a scenario is proposed. All features help to explain the poor ductility of the TiAl based alloys at room temperature.

Multiple births or twinning in equids are dangerous, undesirable situations that compromise the life of the dam and resulting offspring. However, embryo vitrification and freezing techniques take advantage of individuals whose multiple ovulations allow flushing more fertilised embryos from the oviduct to be collected, increasing the productivity and profitability of such techniques. Embryo preservation is especially important in highly endangered populations such as certain donkey (Equus asinus) breeds; for which conventional reproductive techniques have previously failed. For instance, becoming an effective alternative to artificial insemination with frozen semen to preserve the individuals’ genetic material. The objective of this study was to examine the historical foaling records of Andalusian donkeys to estimate genetic parameters for multiple births, assessing the historical foal number born per animal, maximum foal number per birth and multiple birth number per animal. We designed an Animal Model with single records considering the fixed effects of birthyear, birth season, sex, farm, and husbandry system, and age as a linear and quadratic covariate. Restricted maximum likelihood reported heritability estimates ranging from 0.18±0.01 to 0.24±0.01. Genetic and phenotypic correlations ranged from 0.01±0.01 to 0.83±0.01 and 0.12±0.01 and 0.53±0.01, respectively. These estimates enable the potential for selection against/for these traits, offering a new perspective for donkey breeding and conservation.

This study investigates the microstructures and deformation mechanism of hetero-structured pure titanium under different high strain rates (500 s-1，1000 s-1，2000 s-1). The influence of strain rate on the deformation mechanism is examined. As the strain rate increases, the dominance of dislocation slip decreases while deformation twinning becomes more prominent. Notably, at a strain rate of 2000s-1, nanoscale twin lamellae are activated within grain with a size of 500nm, which is a rarely observed phenomenon in pure Ti. Additionally, martensitic phase transformation is also identified. These findings can greatly enhance our understanding of the mechanical responses of Ti and broaden the potential applications of Ti in dynamic deformation scenarios.

For a wide industrial application of magnesium alloys, a method for imparting high damping properties while maintaining mechanical properties is required. Controlling the crystallographic texture seems to be useful, because dislocations are known to have a significant influence on the damping characteristics of magnesium alloys. Therefore, the effect of twinning and annealing, which can affect to the recrystallization were investigated in this study. An AZ31 alloy was hot rolled at 673K with a reduction ratio of 10 % and 50 %, and then annealed at 673K and 723K for 0.5, 1, 2, and 3H respectively. SEM-EBSD was used to examine the microstructure and texture. In addition, each specimen’s hardness and internal friction were contemporarily measured. As a result, hot rolling produced tensile twins and their fraction increased with internal friction when the reduction ratio increased. Due to annealing, a discontinuous type of static recrystallization occurred within the twinning grains, and was highly activated along with the increasing annealing temperature and the fraction of twinning. In the samples annealed at 723K, the internal friction continuously increased over the annealing time, whereas in the samples annealed at 673K, the decrease in dislocation density was delayed while, the internal friction showed a relatively low value.

The evaluation of HAADF-STEM images of a sample with the composition Nb18W16O93 provided new insights in its real structure. The basic structure comprises an intact octahedral framework of the tetragonal tungsten bronze (TTB) type. The partial occupation of the pentagonal tunnels (PT) by metal-oxygen strings determines the oxygen to metal ratio (O/SM with M = Nb,W). For a large area, the O/SM was determined to be 2.755 which is smaller than the value of Nb18W16O93 which is O/SM = 2. 735. To a large extent, the threefold TTB superstructure structure of Nb8W9O47 with a high oxygen content is present (O/SM = 2.765). In addition, a new fourfold TTB superstructure was found in small domains: Nb12W11O63 with an O/SM = 2.739 obviously accommodates a part of the sample’s metal excess compared to the stable phase Nb8W9O47.