Undoped, 5%, and 10% lanthanum doped lithium tantalate thin films were annealed at 550 • C temperature for 12.5 hours and their properties were characterized. The results showed that the dopant addition affects the crystal formation of LiTaO 3 , especially the 10% La 2 O 5 dopant, where the lattice of a = 5.11 Å, c = 13.30 Å, and its crystal was hexagonal. The observed functional groups were O-H, N-H, C = C, Li-O, Ta-O. The higher La 2 O 5 dopant concentration leads to the higher absorption of Ta-O and Li-O, the lower the energy gap, the higher the refractive index, and the smaller the particle size of thin films.

Sycamore maple (Acer pseudoplatanus L.) is a wood species particularly known for its wavy grain figure and its high-value utilization among luthiers and craftsmen for making musical instruments or furniture. In this study, the anatomical and physical-acoustical characteristics of its wood, taken from different trees with various surface figure, were characterized. Vibrational mechanical measurements were conducted taking into account radial and longitudinal directions and local variations, waviness' parameters were quantified on split blocks, and anatomical properties such as microfibril angle and rays' dimensions were measured using light microscopy. Results provide a complete dataset on the properties of sycamore maple showing a gradient of wavy figure. Through statistical analysis, it can be concluded that there exist significant correlations between the measured parameters, particularly between waviness and microfibril angle, and between these anatomical features and the specific modulus of elasticity and damping by internal friction of the wood in longitudinal direction. Anisotropy was found to be very low but was not satisfactorily explained by the studied anatomical features. Prospects for future studies on wavy figure are introduced.

Grenadilla wood (Dalbergia melanoxylon Guill. & Perr.) is a hardwood species found in Tanzania, Mozambique, and other countries in the tropical part of Africa, especially in the Eastern-Central region. Thanks to its high density and good hygroscopic stability, it is used in the making of various musical instruments and fine furniture. Due to the scarcity of published data on this wood species, more studies on its properties are needed to improve its processing and use, and even to search for sustainable alternative materials as its trade is increasingly limited by new regulations. This work is focused on the hygromechanical properties, which hold an important role in the applications of this wood: diffusion coefficients and adsorption-desorption curve (both measured at T = 20 • C), swelling-shrinkage coefficients and full orthotropic elastic constants using an ultrasonic method. Results show that grenadilla wood possesses small water diffusion coefficients (from 1.54 ± 0.49 × 10 −7 cm 2 ∕s in T direction to 4.58 ± 0.84 × 10 −7 cm 2 ∕s in L direction), which is probably related to its high density (1250.0 ± 26.2 kg∕m 2 ); unique equilibrium moisture content (sorption) curve with a lower fiber saturation point (0.173 ± 0.003); smaller swellingshrinkage coefficients (0.20 ± 0.03 and 0.32 ± 0.05 in T and R directions, respectively); and elastic constants lower in the longitudinal direction (15.56 ± 1.79 GPa) and higher in the transverse ones (5.10 ± 0.46 GPa and 4.05 ± 0.35 GPa in R and T directions, respectively) than what could be expected with a standard model based on the density only. Several explanations were described here, from the effects of a high extractive content to the possibility of a high microfibril and/or fiber angle.