Spinel chromite nanoparticles are prospective candidates for a variety of applications from catalysis to depollution. In this work, we used a sol–gel auto-combustion method to synthesize spinel-type MgCr₂O₄ nanoparticles by using fructose (FS), tartaric acid (TA), and hexamethylenetetramine (HMTA) as chelating/fuel agents. The optimal temperature treatment for the formation of impurity-free MgCr₂O₄ nanostructures was found to range from 500 to 750 °C. Fourier transform infrared (FTIR) spectroscopy was used to determine the lattice vibrations of the corresponding chemical bonds from octahedral and tetrahedral positions, and the optical band gap was calculated from UV–VIS spectrophotometry. The stabilization of the spinel phase was proved by X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analysis. From field-emission scanning electron microscopy (FE-SEM), we found that the size of the constituent particles ranged from 10 to 40 nm. The catalytic activity of the as-prepared MgCr₂O₄ nanocrystals synthesized by using tartaric acid as a chelating/fuel agent was tested on the decomposition of hydrogen peroxide. In particular, we found that the nature of the chelating/fuel agent as well as the energy released during the auto-combustion played an important role on the structural, optical, and catalytic properties of MgCr₂O₄ nanoparticles obtained by this synthetic route.

This study aimed to investigate the effects of incorporating carrot pomace from different varieties (Baltimore, Belgrado, Niagara, and Sirkana) into pasta formulations made from durum and common wheat flours, as well as to optimize the addition level and characterize the resulting products. To this end, dough rheological properties, pasta chemical composition, cooking behavior, color, texture, sensory attributes, and microstructure were evaluated. Increasing levels of carrot pomace significantly influenced flour functionality, dough rheology, pasta texture, cooking behavior, and color characteristics. Higher pomace addition resulted in increased flour water absorption, dough complex modulus and hardness, pasta fracturability, cooking losses, and contents of crude fiber and total yellow pigments, while reducing dough deformation resistance, pasta color intensity, and chewiness. The magnitude of these changes was dependent on the carrot variety used. Process optimization allowed the determination of variety-specific optimal inclusion levels of carrot pomace for both flour types. For durum wheat flour, optimal levels ranged from 6.34% to 9.25%, while for common wheat flour they ranged from 8.12% to 11.17%. At these levels, cooking losses remained within acceptable limits (<8%), yellow coloration was enhanced, and dough structure rigidity increased, accompanied by delayed starch gelatinization. Pasta samples containing Niagara and Sirkana pomace showed the highest contents of dietary fiber and yellow pigments, reflecting their elevated β-carotene levels. Sensory evaluation indicated improved overall acceptability compared with control samples. These results demonstrate the potential of carrot pomace as a functional ingredient for the development of nutritionally enriched, value-added pasta products.

We introduce a novel approach to study the dielectric permittivity of spin crossover (SCO) molecular materials using a radio frequency (RF) resonant tunnel diode oscillator (TDO) circuit. By fabricating a parallel plate capacitor using SCO particles embedded into a polymer matrix as an integral part of the LC tank of the TDO we were able to extract the temperature dependence of the dielectric permittivity from frequency measurements for a wide selection of resonance values, spanning from 100 kHz up to 50 MHz, with great precision (less than 2 ppm), in a broad temperature range. By making use of this simple electronic circuit to explore the frequency and temperature dependent dielectric permittivity of the compound Fe[(Htrz)2(trz)]BF4 we demonstrate the reliability and resolution of the technique and show how the results compare with those obtained using complex instrumentation.

We introduce a novel approach to study the dielectric permittivity of spin crossover (SCO) molecular materials using a radio frequency (RF) resonant tunnel diode oscillator (TDO) circuit. By fabricating a parallel plate capacitor using SCO particles embedded into a polymer matrix as an integral part of the inductor (L) capacitor (C) LC tank of the TDO, we were able to extract the temperature dependence of the dielectric permittivity of frequency measurements for a wide selection of resonance values, spanning from 100 kHz up to 50 MHz, with great precision (less than 2 ppm) and in a broad temperature range. By making use of this simple electronic circuit to explore the frequency and temperature-dependent dielectric permittivity of the compound Fe[(Htrz)₂(trz)](BF₄), we demonstrate the reliability and resolution of the technique and show how the results compare with those obtained using complex instrumentation.