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Immobilizing natural antioxidant and biologically active molecules in layered double hydroxides (LDHs) is an excellent method to retain and release these substances in a controlled manner, as well as protect them from thermal and photochemical degradation. Herein, we describe the preparation of host–guest systems based on LDHs and rosmarinic and glycyrrhetinic acids, two molecules obtained from the extraction of herbs and licorice root, respectively, with antioxidant, antimicrobial, and anti-inflammatory properties. Intercalation between the lamellae of the mono-deprotonated anions of rosmarinic and glycyrrhetinic acid (RA and GA), alone or in the presence of an alkyl surfactant, allows for readily dispersible systems in biobased polymer matrices such as poly(lactic acid) (PLA), poly(butylene succinate) (PBS), and a 60/40 wt./wt. PLA/PBS blend. The composites based on the PLA/PBS blend showed better interphase compatibility than the neat blend, correlated with increased adhesion at the interface and a decreased dispersed phase size. In addition, we proved that the active species migrate slowly from thin films of the composite materials in a hydroalcoholic solvent, confirming the optimization of the release process. Finally, both host–guest systems and polymeric composites showed antioxidant capacity and, in the case of the PLA composite containing LDH-RA, excellent inhibitory capacity against E. coli and S. aureus.

Objective To differentially diagnose a calcified formation recovered from a 13th century AD grave from the Tuscan monastery of Badia Pozzeveri, Lucca, Italy. Materials A calcified formation from the thoraco-abdominal region of a skeleton buried in the monastery cemetery. Methods Cone Beam Computed Tomography, Scanning Electron Microscope and Energy Dispersive X-Ray Spectroscopy. Results A hollow, calcified ovoid formation was identified as typical of a hydatid cyst, permitting the diagnosis of cystic echinococcosis in a 35-45year-old female. Conclusions The study reveals the circulation of the parasite Echinococcus granulosus in the region of Lucca in late medieval Tuscany. Significance This finding is the fourth case of cystic echinococcosis from an archaeological context in Italy and provides insight into environmental conditions that appear to have affected members of a community, irrespective of social status. Limitations Caution and the application of multiple analyses must be exercised in the differential diagnosis to discriminate among calcified formations. Suggestions for further research Analysis of stable isotopes of the calcified formation, such as 15N and 13C, in order to compare them with isotopic values of the host individual and to further confirm the parasitic origin of the find.

A novel methodology based on electrochemical hydrogen permeation tests is proposed to study the efficiency of commercial inhibitors for industrial acid pickling of iron and mild steels. Weight loss measurements and hydrogen permeation tests have been carried out in order to compare the sensitivity of different techniques to variations of low inhibitor dosages. It has been found a close dependence between low amounts of filming inhibitors and hydrogen uptake in the metallic surface with related permeation currents. The high sensitivity of permeation currents may be very useful to establish and also control the optimum amount of active substances in industrial pickling baths, with related cost savings. The implementation of the proposed methodology to improve the control of industrial pickling plants is also envisaged, since it would be possible to improve both sensitivity and time response of experimental permeation curves.

Novel materials based on mixtures of immiscible polymers, namely poly (3-hexylthiophene-2,5-diyl) and poly (methyl methacrylate) (P3HT/PMMA), with dispersed phosphorene (2D-bP), obtained by liquid-phase exfoliation (LPE) of black phosphorus (bP) or by in situ polymerization technologies, were prepared for the first time. The new materials were characterized by Raman, UV–Vis, solid state 31P NMR spectroscopies, X-ray diffractometry (XRD), size exclusion chromatography (SEC), morphological (SEM), topographical (AFM) and thermal analysis (DSC and TGA) to investigate the physio-chemical features of both components, polymers and phosphorene owing the composites preparation. Good distribution of the nanoflakes, which preserve their structure and resulted intercalated and partially exfoliated, was achieved thanks to established interactions at the interface between the 2D-bP flakes and the polymers, especially with the P3HT phase, changing the morphology and topography of the mixtures. The preferential allocation of 2D-bP in P3HT, besides inducing a particular polymers phase segregation (a vertical phase separation with P3HT continuous phase onto the surface) encouraged testing these materials as an active layer in Organic Field Effect Transistor (OFET) devices. The data collected showed that the introduction of 2D-bP in P3HT/PMMA polymer mixtures is somewhat promising, giving an increase in mobility up to an order of magnitude with respect to the corresponding 2D-bP-free mixture.

PLA-based composites were prepared by mixing the polymer in the melt with organophilic Mg/Al LDH and Mg Stearate. The obtained materials were therefore characterized in comparison with the unfilled PLA with the aim of investigating the relationships between the morphology of the polymer composites and their thermal stability, crystallinity and mechanical properties. The degradative effects induced by the presence of O-LDH and its organic component (i.e. alkyl carboxylates used as surfactant) were evaluated by analysing the samples with SEC and TGA under standard and modulated conditions, in the presence of nitrogen and air. The collected results proved that the main effects on degradation are due to inorganic reactive species and to increased interfacial surface owing to intercalated/exfoliated morphology. The main thermal transitions of the composites were studied by XRD and DSC (even in modulated conditions) before and after annealing processes at different temperatures. The results inherent to the percentage of crystallinity, the content of rigid amorphous fraction (RAF), and the main size of crystalline domains were discussed by considering the filler nature/content, its dispersion degree in polymer matrix and the annealing temperature. By crystallization at 80 °C the filler promoted both RAF and crystallites size. Unlike unfilled PLA, the composites showed an increase of the stiffness and a general loss of ductility which were tentatively ascribed to annealing at 80 °C and to the extent of interfacial interactions.

Laser beam welding of dissimilar AISI 440C and AISI 430F stainless steels was investigated in a circular constrained configuration. The beam incidence angle and the offset of the focusing position respect to the contact point between the two materials were used as main control parameters to vary the melting ratio inside the seam. The objective of the study is twofold: to avoid surface microcracks related to the high percentage of carbon of the martensitic steel and to enhance the shear strength of the weld by making it less brittle. To reach this scope the effects of incidence angle and offset on weld bead geometry and melting ratio were studied by means of metallographic analyses, microstructure and microhardness characterization. As last step, the weld mechanical strength was tested by tensile-shear stress test on the whole seam. Experiments demonstrated that varying incidence angle and offsetting the focal position is a reliable method to modify the melting ratio and maintaining the expected resistance length at the material interface, as well. It was found that increasing the percentage of ferritic steel into the joint has beneficial effects on the weld quality and on the shear resistance. The critical carbon content determining the mechanical properties in the fusion zone can be calculated by taking into account the melting ratio.

This research activity aims at investigating the hydrogen embrittlement of Maraging steels in connection to real sudden failures of some of the suspension blades of the Virgo Project experimental apparatus. Some of them failed after 15 years of service in working conditions. Typically, in the Virgo detector, blades are loaded up to 50-60% of the material yield strength. For a deeper understanding of the failure, the relationship between hydrogen concentration and mechanical properties of the material, have been investigated with specimens prepared in order to simulate blade working conditions. A mechanical characterization of the material has been carried out by standard tensile testing in order to establish the effect of hydrogen content on the material strength. Further experimental activity was executed in order to characterize the fracture surface and to measure the hydrogen content. Finally, some of the failed blades have been analyzed in DICI-UNIPI laboratory. The experimental results show that the blades failure can be related with the hydrogen embrittlement phenomenon.

In this work, the structural behaviour during tempering of two different heats of 16Cr-5Ni supermartensitic stainless steel has been studied by means of dilatometry, transmission electron microscopy and X-ray diffraction. A thermomechanical simulator (Gleeble 3800) has been also used to characterize the effects on final mechanical properties of different tempering temperatures in the range 600 °C to 700 °C and the influence of sub-zero cooling on industrial double tempering treatments. It has been found that the pre-existence of retained austenite in as-quenched conditions can induce significant differences in the microstructural evolution during tempering and on the final mechanical properties of industrial components, thus inducing problems in controlling final maximum hardness allowable by normative requirements.

This paper investigates the effects of energy density on geometry of the weld seam and development of microstructures at various weld zones. Energy-based local microhardness profiles are made and linked with the formation of the microstructures. Weld resistance at the interface is energy-limited and seam profile only changes from conical to cylindrical after a certain limit of energy input. Microstructures in the fusion zone changes from cellular to columnar dendritic and equiaxed dendritic with increasing energy input. Variation in morphology of microstructures across the fusion zone is evident within the weld. A distinct region exists in between fusion and heat affected zones due to retention of the primary ferrite. Local microhardness reaches its peak in the fusion zone and decreases gradually from fusion zone to base metal of the outer shell. In the inner shell, peak microhardness occurs in HAZ and the local softening relative to fusion zone and HAZ is visible at the fusion boundary.

Palladium nanoparticles are arousing an increasing interest because of their strong activity in heterogeneous catalysis in a wide range of reactions. Driven by the interest of producing Pd nanoparticles to be deposited for catalysis over hydrophobic supports, we investigated their synthesis via Pulsed Laser Ablation in Liquid in several organic solvents, as acetone, ethanol, 2-propanol, toluene, n-hexane. The colloids were produced by using a Nd:YAG ns laser and without the addition of surfactant agents. The morphology, composition, stability and oxidation state of the obtained nanoparticles were investigated by TEM-EDS analysis, UV-vis spectroscopy, X-ray Photoelectron Spectroscopy and micro-Raman spectroscopy. The results evidence that the nature of the solvent influences both the yield and the physico-chemical properties of the produced nanoparticles. While in acetone and alcohols spheroidal, non aggregated and stable particles are obtained, in case of toluene and n-hexane few unstable particles surrounded by a gel-like material are produced. Raman/XPS measurements suggest the presence of amorphous or graphitic carbon onto crystalline Pd nanoparticles, which could have hindered their growth and determined the observed smaller sizes if compared to nanoparticles produced in water. The stability of Pd colloids obtained in acetone and alcohols was attributed to adsorbed anions like enolates or alcoholates; non polar solvents like toluene and n-hexane, unable to give rise to adsorbed anionic species, cannot provide any stabilization to the palladium nanoparticles. XPS analyses also evidenced a partial oxidation of particles surface, with a ratio Pd2+: Pd-0 of 1:2.5 and 1:4 in acetone and ethanol, respectively. (C) 2011 Elsevier B.V.

Bimetallic Pt–Ru nanoparticles supported on carbon substrates have been prepared reproducibly by a simple method that utilizes commercially available metal-organic precursors at low temperature in vacuum. Particles morphology, composition and structure have been investigated using HRTEM, EDX, selected area electron diffraction (SAED) and powder XRD analysis. TEM shows that the obtained nanoparticles are homogeneously dispersed on the substrate surface and exhibit narrow size distribution, the average diameter being ca. 2 nm. Point resolved EDX analysis demonstrates co-presence of both Pt and Ru in each particle, thereby indicating that truly bimetallic nanoparticles have been obtained. Moreover, EDX performed on several areas of the sample evidences uniform particles composition. The latter can be controlled very easily and effectively by regulating the operation temperature during particles preparation. HRTEM imaging shows that the particles possess crystalline structure. Both SAED and XRD analyses indicate presence of nanoparticles exhibiting structure consistent with that of an f.c.c. Pt–Ru alloy. Besides the f.c.c. alloy, an additional crystalline phase might also be present as noticed by SAED. These nanoparticles display electrocatalytic activity with regard to methanol oxidation as evidenced by cyclic voltammetry (CV).

Results concerning the compatibilization and the chemical-physical characterisation of blends of PET and polyolefins (HDPE, PP) obtained from postconsumer packaging materials are presented. The blend compatibilization was carried out by melt mixing and extrusion processes in the presence of a variety of polyolefins functionalized with reactive groups, such as maleic anhydride, acrylic acid, and glycidyl methacrylate. The effect of the type and concentration of compatibilizer, as well as the mixing conditions on the morphology, crystallization behavior, thermal stability, rheological, and dynamic-mechanical properties of the blends was investigated by various techniques, such as scanning electron microscopy, rheometry, differential calorimetry, thermogravimetry, FTIR, NMR, and mechanical analysis.

An organic-inorganic hybrid material, PK-SiO2 (PK = polyketone), was employed as support for Pd catalysts. Their synthesis was carried out by MW irradiation of an ethanol solution of Pd(OAc)2 in the presence of the support. The obtained systems were characterized by solid state NMR, SEM, TEM, ICP, XPS, BET, gas porosimetry and tested in two probe reactions: the selective hydrogenation of cinnamaldehyde to hydrocinnamaldehyde carried out in decalin and the oxidation of 1-phenylethanol to acetophenone in water. For comparison, Pd/PK and Pd/SiO2 catalysts were also prepared by using the same procedure, characterized and tested in the same reactions. On the hybrid support the Pd nanoparticles resulted significantly smaller and with a more homogeneous size distribution compared to those on bare SiO2 or PK. The catalysts on the hybrid support allowed a higher performance and could be recycled up to five times without loss of activity and metal leaching. These results were related to the improved surface area of the hybrid material (compared to the low surface area of bare PK) ascribable to silica introduction, combined with the stabilizing effect of the polymeric counterpart against Pd nanoparticles agglomeration. © 2015 Elsevier B.V. All rights reserved.

Nanostructured ceria has been prepared in mild conditions by hydrolysis of the N , N -dibutylcarbamato complex of cerium(III), [Ce(O 2 CNBu 2 ) 3 ], obtained by lanthanide extraction from aqueous solution into heptane containing CO 2 saturated NHBu 2 . In dependence of the hydrolysis conditions, cerium(III) carbonates or hydroxocarbonate (characterized by IR, XRD and metal content) were obtained. Thermal treatment of these products at relatively low temperature (200 °C) yielded CeO 2 in the form of a light yellow powder. The structure and morphology of the samples were studied by TEM, FESEM and XRD studies. The medium crystallite dimensions, estimated by TEM, appear to be of a few nanometers. Ceria with smaller medium crystallite dimensions was obtained by increasing the amine concentration in the course of the hydrolysis process.

In industrial production processes, the respect of hardness and UTS maximum values of 16Cr5Ni steel is of utmost importance and a careful control of chemical composition and thermo-mechanical treatments is a common practice. Nevertheless, some scatter of properties is often observed with consequent rejection of final components. To better understand the role played by different factors, two heats of 16Cr-5Ni supermartensitic stainless steels with very close chemical compositions but different thermal behavior during tempering have been studied by means of TEM observations, X-ray diffraction measurements, dilatometry, and thermo-mechanical simulations. It has been found that Ms–Mf temperature range can extend below the room temperature and the relative amount of retained austenite in as-quenched conditions plays a significant role in determining the thermal behavior. When present, the γ-phase increases the amount of reversed austenite formed during tempering and accelerates the process kinetics of martensite recovery. Moreover, increasing amounts of retained austenite after quenching lower the critical temperature for austenite destabilization and influence the optimum temperature–time combination to be adopted for controlling final mechanical properties. In the studied cases, the very close chemical composition of the heats was not a sufficient condition to guarantee the same as-quenched structure in terms of retained austenite amount. This was proven to be related to solute segregation effects during solidification of original heats.

The intragranular nucleation of ferrite has been studied in a V microalloyed steel (C=0.103; Mn=1.463; V=0.139; N=0.0100% mass). Using torsion tests and applying the double deformation method known as “back extrapolation”, the recrystrallised fraction of austenite has been determined for several deformation temperatures and two strain values (0.20 and 0.35) and has been plotted as a function of time. Recrystallisation-precipitation-time-temperature (RPTT) diagrams have then been drawn. The RPTT diagrams depict precipitation kinetics as a function of the temperature and time and this information has been used to study the intragranular nucleation of ferrite, cooling specimens from programmed temperatures and moments for which the precipitated volume and the average precipitate size (determined by TEM) are known. The results have allowed us to determine the contribution of intragranular nucleation to ferritic grain refinement, which was approximately 20%.

Digital semeiotics is one of the newest recent challenges for assessing a number of computational descriptors to atherosclerotic cardiovascular diseases that are leading causes of mortality worldwide. These descriptors can be expressed involving (i) morphometric, biometrics and colorimetric of the face; (ii) spectroscopic analysis of skin and iris, of sub-cutaneous substances and the function of subcutaneous tissues, and (iii) compositional analysis of breath and exhaled. In this paper, we describe the design and functionality of the Wize Sniffer (WS), a new portable device for breath analysis limited to an effective number of substances. Within the SEMEOTICON Project by the WS, we intend a hardware/software tool for both the analysis of volatile organic compounds of breath and a platform for data mining and data integration. The WS should be able to provide useful information about the “breathprint”, i.e., the analog of fingerprint for the state of health of an individual.