Analysis on Isotropic and Anisotropic Samples of Polypropylene/Polyethyleneterephthalate Blend/Graphene Nanoplatelets Nanocomposites: Effects of a Rubbery Compatibilizer

Over the past few years, polymer nanocomposites have garnered a significant amount of interest from both the scientific community and industry due to their remarkable versatility and wide range of potential uses in various fields, including automotive, electronics, medicine, textiles and environmental applications. In this regard, this study focuses on the influence of a compatibilizer rubber on a nanocomposite incorporating graphene nanoparticles (GNPs), with a polymer matrix based on a blend of polypropylene (PP) and polyethylene terephthalate (PET). This effect has been investigated on both isotropic samples and on anisotropic/spun fiber samples. The influence of the compatibilizer rubber on morphological, rheological and mechanical properties was analysed and discussed. Mechanical and morphological properties were evaluated on both isotropic samples obtained by compression moulding and melt-spun fibers. The addition of the rubbery compatibilizer increased the viscosity, improving interfacial adhesion, and the same effect was observed for the melt strength and breaking stretching ratios. Mechanical properties, including the elastic modulus, tensile strength and elongation at break, improved in both types of samples but more significantly in the fibers. These improvements were attributed to the orientation of the matrix, the formation of PET microfibrils, and the reduction in the size of graphene nanoparticles due to the action of the elongational flow. This reduction, facilitated by the elongation flow and the action of the compatibilizer, improved matrix-nanofiller adhesion due to the increased contact area between the two polymeric phases and between the filler and matrix. Finally, a transition from brittle to ductile behaviour was observed, particularly in the system with the compatibilizer, attributed to defect reduction and improved stress transmission

Novel utilization of powder-suspension hybrid feedstock in HVAF spraying to deposit improved wear and corrosion resistant coatings

Deployment of a suspension feedstock has been known to alleviate problems associated with using sub-micron and nanosized powder feedstock for thermal spraying of monolithic as well as powder-suspension ‘hybrid’ composite coatings. However, a powder-suspension hybrid feedstock has never been previously used in high-velocity air-fuel (HVAF) spraying. In this work, for the very first time, a chromium carbide (Cr3C2) suspension has been co-sprayed along with an Inconel-625 (IN-625) powder by the HVAF process as an illustrative case study. Two variants of the IN-625 + Cr3C2 hybrid coatings were produced by varying relative powder-suspension feed rates. For comparison, pure IN-625 coating was also deposited utilizing identical spray parameters. Detailed microstructural characterization, porosity content, hardness measurement and phase analysis of the as-deposited coatings was performed. The suspension-derived carbides were retained in the bulk of the coating, resulting in higher hardness. In the dry sliding wear test, the hybrid coatings demonstrated lower wear rate and higher coefficient of friction (CoF) compared to the conventional, powder-derived IN-625 coatings. Furthermore, the wear rate improved slightly with an increase in Cr3C2 content in the hybrid coating. Post-wear analysis of the worn coating, worn alumina ball and the wear debris was performed to understand the wear mechanisms and material transfer in the investigated coatings. In the potentiodynamic polarization test, higher corrosion resistance for hybrid coatings than conventional IN-625 coatings was achieved, indicating that the incorporation of a secondary, carbide phase in the IN-625 matrix did not compromise its corrosion performance. This work demonstrates a novel approach to incorporate any finely distributed second phase in HVAF sprayed coatings to enhance their performance when exposed to harsh environments

Statistical analysis of inter-arrival times of rainfall events for Italian Sub-Alpine and Mediterranean areas

Abstract. In this work a set of time-series of inter-arrival times of rainfall events, at daily scale, was analysed, with the aim to verify the issue of increasing duration of dry periods. The set consists of 12 time-series recorded at rain gauges in 1926–2005, six of them belong to an Italian Sub-Alpine area (Piedmont) and six to a Mediterranean one (Sicily). In order to overcome the problem related to limited sample size for high values of inter-arrival times, the discrete probability polylog-series distribution was used to fit the empirical data from partial (20 yr) time-series. Moreover, a simple qualitative trend analysis was applied to some high quantiles of inter-arrival times as well as to the average extent of rain clusters. The preliminary analysis seems to confirm the issue of increasing duration of dry periods for both environments, which is limited to the ''cold'' season

Throughput and energy efficiency in IEEE 802.11 WLANs: friends or foes?

Proceedings of: 6th International ICST Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QShine 2009 and 3rd International Workshop on Advanced Architectures and Algorithms for Internet Delivery and Applications, AAA-IDEA 2009, Las Palmas, Gran Canaria, November 23-25, 2009Understanding and optimizing the energy consumption of wireless devices is critical to maximize network lifetime and to provide guidelines for the design of new protocols and interfaces. In this work we first provide an accurate analysis of the energy performance of an IEEE 802.11 WLAN, and then we derive the configuration to maximize it. We also analyze the impact of the energy configuration of the device on the throughput performance, and discuss in which circumstances throughput and energy efficiency can be both maximized and where they constitute different challenges.European Community's Seventh Framework ProgramPublicad

Healthy Aging and Dietary Patterns

A number of factors contribute to the complex process of aging, which finally define whether someone will or not develop age-associated chronic diseases in late life. These determinants comprise genetic susceptibility as well as various behavioral, environmental, and dietary factors, all of which have been shown to influence specific pathways regulating the aging process and the extension of life, which makes longevity a multidimensional phenomenon. Although a “miraculous elixir” or a “nutrition pill” are not plausible, researchers agree on the notion that nutritional factors have major impact on the risk of age-associated chronic non-communicable diseases and mortality. In recent years nutrition research in relation to health outcomes has considerably changed from focusing exclusively on single nutrients to considering combinations of foods rather than nutrients in isolation. Although research on specific nutrients is scientifically valid providing crucial evidence on the mechanisms by which nutrition impacts health, the recent switch targeting the multifaceted synergistic interplay among nutrients, other dietary constituents, and whole foods, has promoted emerging interest on the actions of total dietary patterns. This narrative review aims to describe some specific dietary patterns with evidence of associations with reduction in the incidence of chronic diseases allowing older adults to live a long-lasting and healthier life, and confirming the powerful impact nutrition can exert on healthy aging. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Thermal spray coatings for corrosion and wear protection of naval Diesel engines components

Hard chrome plating has been widely used as the standard solution for valves stem, but its limited wear-corrosionresistance and the high toxicity of its galvanic baths suggest to look for suitable alternatives, such as thermalsprayed ceramic-metallic (cermet) and self-fluxing alloys.The present study aims to compare different solutions in terms of corrosion resistance under a selected acidenvironment and of wear resistance both for as-sprayed and post-corrosion samples.Coatings have been deposited by HVOF both on martensitic steel and Ni-based superalloy. A Design of Experimentprocedure has been used for spray parameters optimization, based on porosity and deposition efficiency ofthe coatings. Corrosion tests have shown the effect of porosity of the coatings, while wear tests confirmed thefundamental role of the dispersed hard phases.All the solutions here proposed have shown a significant improvement in terms of corrosion and wear resistancecompared to hard chrome plating

Plant communities and landscape diversity in NW Sicily: The MEMOLA EU FP7 Project case study

The MEMOLA EU FP7 Project case study\u201d was presented at IV International Plant Science Conference (IPSC) held in Parma (Italy) on September 20-22, 2017. The poster focuses on the contribution of botany in the interdisciplinary debate of Memola Project and underline the role plant communities play in understanding the formative processes of the Mediterranean Landscapes

PEER Testbed Study on a Laboratory Building: Exercising Seismic Performance Assessment

From 2002 to 2004 (years five and six of a ten-year funding cycle), the PEER Center organized the majority of its research around six testbeds. Two buildings and two bridges, a campus, and a transportation network were selected as case studies to “exercise” the PEER performance-based earthquake engineering methodology. All projects involved interdisciplinary teams of researchers, each producing data to be used by other colleagues in their research. The testbeds demonstrated that it is possible to create the data necessary to populate the PEER performancebased framing equation, linking the hazard analysis, the structural analysis, the development of damage measures, loss analysis, and decision variables. This report describes one of the building testbeds—the UC Science Building. The project was chosen to focus attention on the consequences of losses of laboratory contents, particularly downtime. The UC Science testbed evaluated the earthquake hazard and the structural performance of a well-designed recently built reinforced concrete laboratory building using the OpenSees platform. Researchers conducted shake table tests on samples of critical laboratory contents in order to develop fragility curves used to analyze the probability of losses based on equipment failure. The UC Science testbed undertook an extreme case in performance assessment—linking performance of contents to operational failure. The research shows the interdependence of building structure, systems, and contents in performance assessment, and highlights where further research is needed. The Executive Summary provides a short description of the overall testbed research program, while the main body of the report includes summary chapters from individual researchers. More extensive research reports are cited in the reference section of each chapter

The sea urchin sns5 chromatin insulator settles a gene therapy vector into an independent domain of expression in the vertebrate genome

One of the critical aspects of introducing a transgene into the eukaryotic genome is the great variability of gene expression due to position effects (1). Chromatin-dependent repressive states could be overcome by incorporation in the transgene of chromatin insulators, functioning to establish and delimit domains of expression. We have previously demonstrated that the sea urchin sns5 DNA element has the typical features of an insulator: by acting as enhancer blocker, it shields promoters from neighboring regulatory elements, and by acting as barrier it buffers a transgene from the propagation of condensed chromatin (2,3). We have investigated the use of sns5 in the field of gene therapy. Our preliminary studies shown that the inclusion of sns5 in \uf0e3-retroviral vectors allows position-independent expression in erythroid cells (4). Moreover, transcription factors and histone modifications mark the sns5 chromatin at the integration site (4), suggesting that sns5 displays mechanisms of action common to other well characterized insulators. Here we show that sns5 increases the likelihood and the expression of a \uf062-globin/lentiviral vector integrated as a single copy in both murine cell clones and in a mouse model of \uf062-thalassemia. It has been proposed that two copies of insulators may direct the formation of a chromatin loop by interaction among protein complexes assembled on their sequences (5). Intriguingly, by using the 3C technology, we found that sns5-flanked vectors integrated at a single copy in the resident genome are specifically organized into an independent chromatin structure. Our findings highlight that sns5 could be a promising tool for improving the performance of vectors in the field of gene therapy. 1. Gaszner and Felsenfeld (2006). Nat Rev Genet 7:703-13 2. Palla et al (1997). PNAS USA 94:2272-7 3. Cavalieri et al (2009). Nucleic Acids Res 37:7407-15 4. D'Apolito et al (2009). Mol Ther 17:1434-41 5. Wallace and Felsenfeld (2007). Curr Op Genet Dev 17:400-