Meteorites provide access to information on the formation and evolution of planetary bodies which is otherwise difficult to study. The unique nature of these samples and their relative scarcity means that non-destructive analysis techniques are needed to study their properties. This paper uses the laser ultrasound technique spatially resolved acoustic spectroscopy to non-destructively determine both the crystal orientation and the single crystal elastic constants (Cif) of a sample of the Gibeon meteorite. There are no published values to directly compare the results of this study, as non-destructive measurements of the single crystal elasticity on granular material have not been possible. Therefore, comparisons with theoretical values for man-made iron-nickel alloys are given showing the Cif values are in the expected range. There are studies providing bulk elastic properties of meteorites, and so calculated bulk properties derived from the single crystal elasticity measurements are compared and also agree well.
This study formulated biodegradable, edible films with sodium alginate and varying concentrations and a combination of seed oils (watermelon seed oil, sesame seed oil) and rosehip extract. In the present study, rosehip, sesame, and watermelon seed oils, which incorporated many bioactive compounds and are known to have antioxidant properties, were incorporated into edible films to improve the film properties due to the controlled release of the active substance and thus increase the storage time. The potential to form alginate-based edible films by incorporating this extract and seed oils into alginate-based films has not been thoroughly investigated. Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and mechanical, physical, thermal, and antioxidant properties characterized the edible film samples. The biodegradability by soil was also performed. Blending rosehip extract and its combination with seed oils significantly improved the films' antioxidant properties while reducing moisture content. In the study, the highest total phenolic content was recorded in the rosehip + sesame oil film (R2) sample (0.418 +/- 0.015 mg GAE/g) and the lowest total phenolic content was recorded in the control sample (0.208 +/- 0.014 mg GAE/g). Additionally, the highest % moisture value was recorded in the control sample (68.060 +/- 0.530%), and the lowest % moisture value was recorded in the rosehip + sesame oil film (R2) sample (61.223 +/- 0.881%). Watermelon seed oil blended film samples showed more homogeneity and had smooth surfaces compared to control samples. Alginate-based films incorporated with seed oils and rosehip extract may have caused color differences and whiteness index due to phenolic and bioactive compounds in their content. Soil degradation properties showed that the films were biodegradable. The elongation at break value of alginate-based films combined with rosehip extract and seed oils showed a significant increase compared to the control films. According to the results, alginate-based films combined with rosehip extract (films compounded with rosehip extract only and films compounded with rosehip and selected seed oils) improved film properties compared to control films. In addition, the incorporation of rosehip extract into the films improved the film properties compared to the films obtained using only seed oil. Based on the findings of this study, the use of rosehip extract, sesame, and watermelon seed oil in the development of composite biodegradable, edible films of sodium alginate could be used as a suitable alternative for edible food packaging.
Earth concrete is composed of fine particles which make them very sensitive to humidity and affects their longterm durability. In this study, the effect of wetting/drying cycles on earth concrete according to ASTM D559 was studied by measuring the weight loss, pH, and Electrical Conductivity (EC). The effect of different percentages of flax fibers was investigated. The residual properties of reference specimens and earth concrete specimens subjected to wetting/drying cycles were evaluated by conducting compressive tests at the end of the 25 cycles. Ultrasound, Acoustic Emission (AE), and Digital Image Correlation (DIC) techniques were applied to estimate the concrete progressive deterioration during and at the end of the 25 wetting/drying cycles. The results showed that earth concrete degradation begins during the first cycle with visible cracks on the surface of the specimens. The mechanical tests showed a considerable loss of earth concrete mechanical properties after 25 cycles. The ultrasonic test showed that the degradation rate was more important for specimens without flax fibers. The cumulative acoustic activity was effectively used to assess the different damage progression phases and crack propagation. The signal parameters (energy, amplitude, etc.) evolution indicates premature damage for earth concrete specimens subjected to wetting drying cycles.