Innovative metamodelling-based process design for manufacturing: an application to Incremental Sheet Forming

The use of metamodelling techniques in process design has become indispensable to perform faster solutions reducing time to market. This approach allows the implementation of decision support tools which are easier to use than the conventional numerical simulations. In this paper, a robust metamodelling technique has been designed and its feasibility has been validated for the crucial problem of localised thinning in sheet metal forming process. The proposed methodology is based on the innovative integration between the Design of Experimental statistical method and the Kriging one. This approach, in fact, allows to analyse contemporary the continuous and categorical factors and, as a consequence, to define a single tool for changing process conditions (i.e., material and product shape). To test the reliability of the mathematical approach, the same was performed for the case study of Incremental Sheet Forming, a process strongly affected by the not homogeneous distribution of the thickness. Taking advantage of this strategy, a wide experimental investigation has been performed to build the base of knowledge of the problem both for the metamodelling design and for the validation of the decision support tool; moreover, the experimental data were utilized to set and validate a numerical model, which was subsequently used to enrich the dataset. The proposed metamodel, suitably modified according to each process peculiarities, can be generally adapted for sheet thickness prediction.     

Towards a Digital Library Policy and Quality Interoperability Framework: The DL.org Project

Interoperability is a property referring to the ability of systems and organizations to work together. Today interoperability is recognized as a key step in the shift from isolated digital libraries toward a common information space that will allow users to browse through different digital libraries within a single integrated environment. In this paper, we discuss the premises underlying a novel Policy and Quality Interoperability Framework, taking into account the preliminary outcomes and the recommendations of the Policy and Quality Working Groups that are currently being run by the EU co-funded project Digital Library Interoperability, Best Practices, and Modeling Foundations (DL.org).     

Towards the development of a novel bioinspired functional material: Synthesis and characterization of hybrid TiO2/DHICA-melanin nanoparticles

A large number of recent literature data focus on modification/modulation of surface chemistry of inorganic materials in order to improve their functional properties. Melanins, a wide class of natural pigments, are recently emerging as a powerful organic component for developing bioinspired active material for a large number of applications from organoelectronics to bioactive compounds.Here we report the use of the approach referred as “chimie douce”, involving in situ formation of the hybrids through reactions of precursors under mild conditions, to prepare novel hybrid functional architectures based on eumelanin like 5,6 dihydroxyindole-2-carboxylic acid (DHICA) polymer and TiO₂. Two synthesis procedures were carried out to get DHICA-melanin coated TiO₂ nanoparticles as well as mixed DHICA/TiO₂ hybrid nanostructures. Such systems were characterized through EPR, FT-IR and fluorescence spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and TEM microscopy in order to assess the effect of synthesis path as well as of DHICA content on structural, morphological and optical properties of TiO₂ nanostructures. In particular, EPR, FT-IR spectra and TGA analysis confirmed the presence of DHICA-melanin in these samples. TEM measurements indicated the formation of the nanoparticles having relatively narrow size distribution with average particle size of about 10 nm. DHICA-melanin does act as a morphological agent affecting morphology of hybrid nanostructures. XRD analysis proved that TiO₂ hybrid nanoparticles kept anatase structures for DHICA-melanin contents within the range of investigated compositions, i.e. up to 50% wt/wt.     

The effect of thiol content on the gelation and mucoadhesion of thiolated poly(aspartic acid)

A synthetic poly(amino acid), poly(aspartic acid) modified with thioethyl side groups, was studied as an in situ gelling and mucoadhesive dosage form. The chemical structure and the controllable, large thiol content of the polymer were confirmed using ¹H NMR spectroscopy and Ellman's assay. In situ gelation of aqueous polymer solutions was induced by oxidation and monitored using oscillation rheometry. The strength of mucoadhesion towards excised mucosa was characterised by tensile tests in ex vivo experiments. Release kinetics of ophthalmic antibiotic ofloxacin was studied from an in situ crosslinked hydrogel and a liquid formulation to prove the sustained release of the former. © 2017 Society of Chemical Industry     

Unveiling the controversial mechanism of reversible Na storage in TiO2 nanotube arrays: Amorphous versus anatase TiO2

Due to their inherent safety,low cost,and structural stability,TiO2 nanostructures represent a suitable choice as anode materials in sodium-ion batteries.In the recent years,various hypotheses have been proposed regarding the actual mechanism of the reversible insertion of sodium ions in the TiO2 structure,and previous reports are often controversial in this respect.Interestingly,when tested as binder-and conducting additive-free electrodes in laboratory-scale sodium cells,amorphous and crystalline (anatase) TiO2 nanotubular arrays obtained by simple anodic oxidation exhibit peculiar and intrinsically different electrochemical responses.In particular,after the initial electrochemical activation,anatase TiO2 shows excellent rate capability and very stable long-term cycling performance with larger specific capacities,and thus a clearly superior response compared with the amorphous counterpart.To obtain deeper insight,the present materials are thoroughly characterized by scanning electron microscopy and ex situ X-ray diffraction,and the insertion of sodium ions in the TiO2 bulk phases is systematically modeled by density functional theory calculations.The present results may contribute to the development of more systematic screening approaches to identify suitable active materials for highly efficient sodium-based energy storage systems.     

Exploring the Role of Genetic Variability and Lifestyle in Oxidative Stress Response for Healthy Aging and Longevity

Oxidative stress is both the cause and consequence of impaired functional homeostasis characterizing human aging. The worsening efficiency of stress response with age represents a health risk and leads to the onset and accrual of major age-related diseases. In contrast, centenarians seem to have evolved conservative stress response mechanisms, probably derived from a combination of a diet rich in natural antioxidants, an active lifestyle and a favorable genetic background, particularly rich in genetic variants able to counteract the stress overload at the level of both nuclear and mitochondrial DNA. The integration of these factors could allow centenarians to maintain moderate levels of free radicals that exert beneficial signaling and modulator effects on cellular metabolism. Considering the hot debate on the efficacy of antioxidant supplementation in promoting healthy aging, in this review we gathered the existing information regarding genetic variability and lifestyle factors which potentially modulate the stress response at old age. Evidence reported here suggests that the integration of lifestyle factors (moderate physical activity and healthy nutrition) and genetic background could shift the balance in favor of the antioxidant cellular machinery by activating appropriate defense mechanisms in response to exceeding external and internal stress levels, and thus possibly achieving the prospect of living a longer life.     

Characterization of Uva Longanesi Red Wine by Selected Parameters Related to Astringency

This research represents a first attempt to chemically characterize wines produced from the autochthonous grape variety, Uva Longanesi, based upon the phenolic compounds responsible for its high astringency as confirmed by preliminary sensory analysis. In addition, a wine produced from Sangiovese, the most popular grape variety in the Emilia-Romagna region, was analyzed for comparative purposes. Results showed that Uva Longanesi wine had a higher pH, alcohol concentration, and total dry extract than the Sangiovese wine. With regards to phenolic constituents, the Uva Longanesi wine had higher color parameters and greater concentrations of total phenolics, including monomeric anthocyanins, small polymeric pigments, and tannins. The phenolic composition of Uva Longanesi wine was found to be responsible for the high reactivity of the wine during fining trials.