This work investigates the effects of gamma irradiation (0.1–10 kGy) on four Italian wheat matrices, such as durum, conventional soft, integrated soft, and biological soft wheat, by coupling Raman, FTIR-ATR and EPR spectroscopies to provide complementary insights into the structural, conformational, and radical-based transformations occurring in starch, the primary polysaccharide in wheat. As a general trend, gamma irradiation up to 10 kGy does not induce drastic degradation or depolymerization of wheat components. However, deeper investigations reveal that wheat composition is crucial in modulating the effects of gamma irradiation on structural and conformational rearrangements of starch units. Raman and FTIR-ATR spectroscopy analyses showed an increase in random coil fractions, with the most significant changes observed in durum wheat, plausibly attributed to its higher protein content. EPR analyses confirmed a dose-dependent increase in free radicals, with different recombination kinetics between wheat types influenced by their intrinsic composition and molecular organization. The proposed spectroscopic approaches allow for rapid and non-destructive analyses of molecular structure, chemical composition, and free radical content in irradiated wheat matrices with minimal sample preparation. These approaches can be extended in the development of screening methods for a wide range of polysaccharides in a variety of crops.

Parabolic trough concentrated solar power (CSP) plants are particularly promising renewable sources of energy, whose easy integration with thermal energy storage (TES) systems allows to mitigate the intermittency of electricity generation. Currently, molten nitrates, with two tanks arrangement, are mainly used for sensible heat accumulation. To reduce costs and make the CSP storage systems more manageable, single tank configurations have been proposed, where the cold and hot fluids are stored in the same container and separated because of their density difference. The aim of the present work is to study the storage performances presented by two novel ternary and quaternary mixtures, proposed within the European project IN POWER. An experimental campaign was preliminarily performed to investigate the fluids thermo-physical properties, and the obtained values were utilized as input data to model the discharge phase in a thermocline tank. The simulation results were compared with the ones acquired considering two commercial materials, namely, solar salt and Hitec XL®. Overall, considering same temperature ranges, higher discharging times are obtained for the quaternary and ternary mixtures, with the ternary presenting a smaller thermocline thickness than the solar salt while this parameter is the same considering the quaternary and Hitec XL®.

Thermal oils have been utilized as heat transfer fluids for several decades in many applications, including industrial facilities, power plants and solar receiver systems. Despite their large employment, very few data are available about oils behavior under thermal stress and related degradation processes. For these reasons, the thermal stability of a silicone-based diathermic oil, Bluesil FLD 550 HT, was investigated in the present work. A laboratory-scale set-up was assessed to perform controlled heating tests, and fresh and thermally aged oils samples were analyzed to determine changes in chemical composition and thermo-physical features. Degradation products in the gaseous and vapor phase were also detected and analyzed by online and offline measurements. The obtained results are compared with the ones present for aromatic oils, largely employed as heat transfer media. Bluesil showed a higher thermal resistance compared to aromatic materials, and, thanks to its low volatility together with a high chemical stability, it was successfully tested up to 500 °C. According to its polymeric structure, thermal degradation processes occur mainly through Si-O bond scission, leading to both the segmentation of silicone chains and the formation of cross-linked species as byproducts.

This work investigates the effects of gamma irradiation (0.1–10 kGy) on four Italian wheat matrices, such as durum, conventional soft, integrated soft and biological soft wheat by coupling Raman, FTIR-ATR and EPR spectroscopies to provide complementary insights into the structural, conformational, and radical-based transformations occurring in starch, the primary polysaccharide in wheat. As a general trend, gamma irradiation up to 10 kGy does not induce drastic degradation or depolymerization of wheat components. However, deeper investigations reveal that wheat composition is crucial in modulating the effects of gamma irradiation on structural and conformational rearrangements of starch units. Raman and FTIR-ATR spectroscopy analyses showed an increase in random coil fractions with the most significant changes observed in durum wheat, plausibly attributed to its higher protein content. EPR analyses confirmed a dose-dependent increase in free radicals, with different recombination kinetics between wheat types, influenced by their intrinsic composition and molecular organization. The proposed spectroscopic approaches allow for rapid and nondestructive analyses of molecular structure, chemical composition and free radical content in irradiated wheat matrices with minimal sample preparation. These approaches can be extended in the development of screening methods for a wide range of polysaccharides in a variety of crops.