Simultaneous Microwave Extraction and Separation of Volatile and Non-Volatile Organic Compounds of Boldo Leaves. From Lab to Industrial Scale

Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC) from non-Volatile Organic Compounds (NVOC) of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant.     

HA/β-TCP plasma sprayed coatings on Ti substrate for biomedical applications

The present work focuses on the fabrication of βTCP (β-tricalcium phosphate) and HA/βTCP (hydroxyapatite/β-tricalcium phosphate) composite coatings by plasma spraying. The starting powders were produced via solid-state method using 2 wt% MgO to stabilize βTCP phase. The synthesized powders were preliminarily granulated to be used by the plasma spray process. Coatings obtained on titanium substrates are uniform and well adherent but due to the high temperature and cooling rate typical for plasma spraying process, βTCP phase is almost totally transformed into the α allotrope. Thermal treatment at 800 °C allows the reconversion of the phase αTCP→ βTCP. It is therefore possible to produce coatings with tuneable dissolution properties by selecting the proper initial powder mixture and the specific thermal treatment.     

Eumelanin for nature‐inspired UV‐absorption enhancement of plastics

In the human body, the black‐brown biopigment eumelanin blocks harmful ultraviolet (UV) radiation. In the plastics industry, additives are often added to polymers to increase their UV‐absorption properties. We herein report an assessment of the biopigment eumelanin as a nature‐inspired additive for plastics to enhance their UV absorption. Since eumelanin is produced by natural sources and is nontoxic, it is an interesting candidate in the field of sustainable plastic additives. In this work, the eumelanin‐containing films of commercial ethylene–vinyl acetate copolymer, a plastic used for packaging applications, were obtained by melt compounding and compression molding. The biopigment dispersion in the films was improved by means of the melanin free acid treatment. It was observed that eumelanin amounts as low as 0.8 wt% caused an increase of the UV absorption, up to one order of magnitude in the UVA range. We also evaluated the effect of eumelanin on the thermal stability and photostability of the films: the biopigment proved to be double‐edged, working both as UV‐absorption enhancer and photo‐prooxidant, as thermogravimetric analysis and infrared spectroscopy revealed. © 2019 Society of Chemical Industry     

Co-doped willemite ceramic pigments: Technological behaviour,crystal structure and optical properties

Cobalt-doped willemite is a promising blue ceramic pigment, but some important aspects concerning crystal structure, optical properties and technological behaviour are still undisclosed. In order to get new insight on these features, willemite pigments (Zn_2?xCo_xSiO₄, 0 < x < 0.3) were synthesized by the ceramic route and characterized from the structural (XRPD with Rietveld refinement), optical (DRS and colorimetry), microstructural (SEM, STEM, TEM, EDX, EELS) and technological (simulation of the ceramic process) viewpoints. The incorporation of cobalt in the willemite lattice, taking preferentially place in the Zn1 tetrahedral site, induces an increase of unit-cell parameters, metal–oxygen distances, and inter-tetrahedral tilting. It causes shifting and enhanced splitting of spin-allowed bands of Co²⁺ in tetrahedral coordination, implying slight changes of crystal field strength Dq and Racah B parameter, but increasing spin-orbit coupling parameter λ. Willemite pigments impart deep blue hue to ceramic glazes and glassy coatings with a colouring performance better than commercial Co-bearing colorants in the 800–1200 °C range. Detailed SEM-TEM investigation and microanalysis proved that no diffusion phenomena occur at the pigment–glassy coating interface and that willemite pigments are chemically inert during firing at 1050 °C.     

Application of a spectroscopic method to estimate the olive oil oxidative status

A rapid Fourier transformed infrared (FTIR) attenuated total reflectance (ATR) spectroscopic method coupled with partial least squares (PLS), was developed to estimate the oxidation degree of extra virgin olive oil (EVOO). The reference values of EVOO oxidation for the FTIR calibration were obtained by the specific absorptions at 232 and 270 nm, due to the presence of conjugated diene (CD) and conjugated triene (CT) groups, as monitored by the UV spectrophotometric determination. Specific washing procedures were applied to the EVOO to obtain EVOOP and EVOOTP samples, without phenolic compounds and without tocopherols and phenols, respectively. To obtain different oxidation degrees covering wide CD and CT ranges, EVOO, EVOOP, and EVOOTP samples were subjected to a forced oxidation at 60°C for 20 days and aliquots of the oils were daily analyzed. Regression of the FTIR/PLS‐predicted CD and CT of individual oxidized oils EVOO, EVOOP, EVOOTP, and all combined oils (EVOOALL) against UV–Visible reference values demonstrated the good quality of the models in terms of R² and RMSECV values. The results of the study indicated that a strong correlation existed between FTIR and UV–Visible peak intensities. Practical applications: The FTIR‐ATR method coupled with PLS elaboration was developed and applied to predict the oxidation degree of EVOO samples with considerable advantages in terms of simplicity, analysis time, and solvent consumption as compared to the standard method. Moreover, suitable adjustments of the equipment could permit a rapid control at‐line in oil sector.     

Characterisation and application of new carboxylic acid-functionalised ruthenium complexes as dye-sensitisers for solar cells

A series of ruthenium complexes with and without TiO₂ anchoring carboxylic acid groups have been synthesised and characterised using nuclear magnetic resonance (NMR), UV–vis and luminescence. These complexes were adsorbed on thin films of the wide band-gap semiconductor anatase and were tested as photosensitisers under standard conditions. I/V characteristics of such devices revealed superior performance of the non-symmetric complexes [4′-(4-bromophenyl)-[2,2′; 6′,2″] terpyridine]Ru(II) [4′-(4-bromophenyl)-[2,2′; 6′,2″] terpyridine-4,4″-dicarboxylic acid] and [2,2′; 6′,2″] terpyridine Ru(II) [2,2′; 6′,2″] terpyridine-4′-carboxylic acid with a maximum output power 0.016 mW cm⁻² under illumination at 100 mW cm⁻² AM1.5 and efficiencies 3 times higher than the symmetric complexes.     

Mesoporous alumina obtained by combustion synthesis without template

Mesoporous alumina has been synthesised by the solution combustion synthesis method. While often the synthesis of mesoporous materials with a relatively narrow pore distribution requires the use of a template, this technique allows a simple and rapid synthesis of pure alumina without the use of any templating agent: by regulating the synthesis conditions is possible to obtain from relatively low surface area α-alumina to high surface mesoporous γ-alumina. The porosity of the latter was assessed chiefly by density functional method and was found to be in the range 2.8–3.5 nm. Low angle X-ray diffraction experiments demonstrated a partial ordering of the structure, with a periodicity in the range 5.5–6.9 nm. The addition of lanthanum to the alumina was tested and found to confer a good temperature resistance to the alumina, without modifying the mesoporous structure. After a prolonged heat treatment at 900 °C the mesoporosity of lanthanum-modified samples was retained, even if the pores size increased and the specific surface area decreased.     

How “Authentic Intentionality” can be Enabled: a Neurocomputational Hypothesis

According to John Haugeland, the capacity for “authentic intentionality” depends on a commitment to constitutive standards of objectivity. One of the consequences of Haugeland’s view is that a neurocomputational explanation cannot be adequate to understand “authentic intentionality”. This paper gives grounds to resist such a consequence. It provides the beginning of an account of authentic intentionality in terms of neurocomputational enabling conditions. It argues that the standards, which constitute the domain of objects that can be represented, reflect the statistical structure of the environments where brain sensory systems evolved and develop. The objection that I equivocate on what Haugeland means by “commitment to standards” is rebutted by introducing the notion of “florid, self-conscious representing”. Were the hypothesis presented plausible, computational neuroscience would offer a promising framework for a better understanding of the conditions for meaningful representation.     

Robust Multilayer Control for Enhanced Wireless Telemedical Video Streaming

M-health is an emerging area of research and one of the key challenges in future research in this area is medical video streaming over wireless channels. Contrasting requirements of almost lossless compression and low available bandwidth have to be tackled in medical quality video streaming in ultrasound and radiology applications. On one side, compression techniques need to be conservative, in order to avoid removing perceptively important information; on the other side, error resilience and correction should be provided, with the constraint of a limited bandwidth. A quality-driven, network-aware approach for joint source and channel coding based on a controller structure specifically designed for enhanced video streaming in a robotic teleultrasonography system is presented. The designed application based on robotic teleultrasonography is described and the proposed method is simulated in a wireless environment in two different scenarios; the video quality improvement achievable through the proposed scheme in such an application is remarkable, resulting in a peak signal-to-noise ratio (PSNR) improvement of more than 4 dB in both scenarios.