Microwave characterization of polymer composite based on Biochar: A comparison of composite behaviour for Biochar and MWCNTs

In this work, Biochar is used as a filler in Epoxy resin for composite preparation. The electrical characteristics of composites are analyzed in function of different filler percentages. Results obtained are compared with composites based on multi-wall carbon nanotubes

Plasma defect-engineering of bulk oxygen-deficient zirconia

Oxygen-deficient zirconia (ZrO2-x) has recently emerged as a promising material for light absorption and photocatalytic applications. However, the economic and environmentally friendly manufacture of bulk ZrO2-x remains challenging and has limited widespread adoption. In this study, we present a novel low-pressure (300 Pa) plasma treatment (H2 gas at 500 °C for 5 h) capable of producing fully-dense bulk ZrO2-x without significant structural modifications. EPR (electron paramagnetic resonance) and XPS (X-ray photoelectron spectroscopy) characterisation of the plasma treated zirconia indicate the formation of Zr3+ ions and F2+ (VO··) centres. The increase of oxygen vacancies is also supported by the greater exothermic heat flow and relative mass gain observed through TGA (thermogravimetric analysis) and DSC (differential scanning calorimetry) analyses. Diffuse reflectance spectroscopy (DRS) reveals a substantial enhancement in light absorption, with an average increase of 66.2 % and >65 % absolute absorption across the entire spectrum (200–3000 nm). XPS and DRS measurements suggest significant reduction in both direct (from 4.84 to 2.61 eV) and indirect (from 3.19 to 1.45 eV) bandgap transition. By effectively enhancing the light absorption capability, reducing bandgap transitions, and maintaining the structural integrity of zirconia, low-pressure plasma treatments offer a promising and scalable approach for the environmentally friendly production of next-generation ZrO2-x materials

Investigation of Carbon Fibres Reclamation by Pyrolysis Process for Their Reuse Potential

During Carbon Fibre Reinforced Polymers (CFRPs) manufacturing, large quantities of scrap are being produced and usually disposed to landfill or incinerated, resulting in a high environmental impact. Furthermore, CFRP parts that have been damaged or reached their end-of-life, follow the same disposal route and because of this, not only the environment is affected, but also high added-value materials, such as carbon fibres (CFs) are lost without further valorisation. Several recycling technologies have been suggested, such as pyrolysis, to retrieve the CF reinforcement from the CFRPs. However, pyrolysis produces CFs that have residual resin and pyrolytic carbon at their surface. In order to retrieve clean long fibres, oxidation treatment in high temperatures is required. The oxidation treatment, however, has a high impact on the mechanical properties of the reclaimed CFs; therefore, an optimised pyrolysis procedure of CFRPs and post-pyrolysis treatment of reclaimed fibres (rCFs) is required. In this study, CFRPs have been subjected to pyrolysis to investigate the reclamation of CF fabrics in their primal form. The temperature of 550 °C was selected as the optimum processing temperature for the investigated composites. A parametric study on the post-pyrolysis treatment was performed in order to remove the residues from the fabrics and at the same time to investigate the CFs reusability, in terms of their mechanical and surface properties

Effets de l'ozone sur la forêt et la végétation dans les Alpes franco-italiennes.

Depuis le début des années 80, dans le sud des Alpes (frontière franco-italienne), plusieurs essences ont présenté des endommagements de leur feuillage avec un déficit foliaire bien marqué. Des premières études ont montré que la pollution par l'ozone influait sur le mauvais état de santé général des peuplements concernés. A partir de 1999, il importait d'évaluer (programme européen Interreg II) l'impact spécifique de la pollution par l'ozone sur les dommages observés. Les premiers résultats ont révélé des concentrations en ozone élevées. Parallèlement, l'endommagement foliaire a été estimé sur des placettes forestières. Ont été recherchés également des symptômes spécifiques de l'ozone sur quelques essences arborées, mais aussi sur toute la végétation de proximité. Des essais de corrélation ont été réalisés entre les niveaux d'ozone et les dégâts foliaires observés et des analyses microscopiques ont permis de confirmer la spécificité des dégâts observés

A narrative review of epidemiology and prevention of lung cancer: sex/gender differences?

Background and Objective: Sex and gender-related factors can both differently influence cancer susceptibility, progression, survival, and therapeutic response. Nevertheless, these differences are not extensively studied. The aim of this narrative review is to summarize sex/gender related differences in lung cancer epidemiology, the burden of its risk factors, and the role of prevention. Methods: Through PubMed Central and official websites of International and European Agencies and Societies, recent evidence about potential differences between males and females in lung cancer epidemiology (prevalence, temporal/spatial trend, biomarkers), risk factors (tobacco smoking and air pollution) and prevention coming from international reports and original studies have been selected. The study was limited to published original manuscripts/reviews/reports in the English language from 1990 to 2021. Key Content and Findings: Lung cancer is the most commonly diagnosed cancer (11.4% of the total cases), and the leading cause of cancer death (18.0% of the total cancer deaths). An increasing lung cancer incidence and mortality trends, largely but not only due to the increasing smoking prevalence, were evidenced among women. Females seem to be more susceptible to carcinogenic effect of tobacco smoke, and hormonal factors, use of hormone replacement therapy (HRT) and genetic predisposition are suggested to affect susceptibility to lung cancer. The incidence of lung cancer among females is globally increasing also in those who doesn’t smoke. Therefore, it becomes important to investigate the influence of other factors such as environmental tobacco exposure (ETS), outdoor and indoor air pollution, occupational exposure to hazardous chemicals and radon exposure from soil and building materials. The risk of lung cancer can be significantly reduced with tobacco cessation. Sex/gender differences in smoking cessation rates have been hypothesized with contrasting results. Conclusions: Lung cancer prevalence, trend and susceptibility as well as efficacy of risk factors preventive measures (e.g., smoking cessation) are a result of sex and gender differences, thus both aspects should be considered as contributing factors in lung cancer management

Mechanical properties, surface assessment, and structural analysis of functionalized cfrps after accelerated weathering

The present study focuses on the effect of two novel carbon fibre surface treatments, electropolymerisation of methacrylic acid and air pressure plasma, on the mechanical properties and structural integrity of carbon-fibre-reinforced composites under operational conditions. Extensive mechanical testing was applied, both in nano-and macro-scale, to assess the performance of the composites and the interphase properties after ultraviolet/humidity weathering. The results of the mechanical assessment are supported by structure, surface, and chemistry examination in order to reveal the failure mechanism of the composites. Composites with the electropolymerisation treatment exhibited an increase of 11.8% in interlaminar shear strength, while APP treatment improved the property of 23.9%, rendering both surface treatments effective in increasing the fibre-matrix adhesion. Finally, it was proven that the developed composites can withstand operational conditions in the long term, rendering them suitable for a wide variety of structural and engineering applications

Screening of a Small Number of Italian COVID-19 Syndrome Survivors by Means of the Fatigue Assessment Scale: Long COVID Prevalence and the Role of Gender

Months after healing, a number of COVID-19 syndrome survivors are affected by both psychological and physical limitations. They are mainly troubled with long-term fatigue, which is a crucial aspect of Long Covid syndrome. This paper aims to investigate the level and persistency of fatigue among COVID-19 survivors from the first wave of the pandemic in Western Liguria and to elucidate the role of gender, age, and lifestyle. It also provides data to the scientific community to help drawing a consistent picture of Long Covid syndrome. The patients were requested to fill a Fatigue Assessment Questionnaire twice: (i) a few weeks after discharge from hospital or home confinement and (ii) a few months later. Statistical analysis was carried out on the global scores and on the score for every single item of the questionnaire. The outcome of the two questionnaires were analyzed separately and compared. Females are more affected by fatigue than males. This results holds for both physical and mental fatigue. All the males’ fatigue scores were reduced at the second control, while 40% of females worsened it. Home-confined patients showed a higher fatigue score at the first check. In the initial stages of the recovery, patients are more affected by physical, rather than mental, fatigue. This is worth of further investigation as well as the reasons leading to a higher initial fatigue score for home cared patients

Evaluation of [C(sp3)/[C(sp2)] ratio in diamondlike films through the use of a complex dielectric constant

The evaluation of the amount of tetrahedral and trigonal cross-linking, that is, the sp3- and sp2-hybridized carbon, is of great importance in understanding the properties of amorphous carbon films. In this paper we report a method for deducing the [sp3]/[sp2] ratio from the experimental values of the complex dielectric constant as obtained by optical transmittance and reflectance measurements. We assume a Gaussian-like distribution of π and π* electronic densities of states in order to fit the contribution of π→π* to the imaginary part, ε2, of the dielectric constant in the low-energy region. Through the Kramers-Kronig relationships we deduce the corresponding values of the real part ε1 of the dielectric constant for such transitions. By subtracting these values from the measured ε1 we deduce the contribution of σ→σ* to ε1. The Wemple-Didomenico model has been used to obtain the dispersion energy and the average excitation energy. Knowing the plasmon energies, we apply the ‘‘f-sum rule'' to deduce the [sp3]/[sp2] ratio. The method applied to a-C:H films deposited by rf diode sputtering provides results in agreement with those obtained by other techniques

Tetrahedrally bonded ternary amorphous semiconductor alloys

The properties of tetrahedrally bonded ternary amorphous semiconductors a-CSiSn:H and a-CSiGe:H are reviewed with particular emphasis on the temperature dependence of dark conductivity and the coordination in random networks. It is shown here that the dark conductivity as a function of the temperature strongly depends on the carbon content and, more precisely, on the proportion of sp3 and sp2 sites in the carbon. Ternary alloys with different carbon contents are compared to binary alloys using the average coordination number. The ternary alloys have an average coordination number close to the optimal value predicted for amorphous covalent networks

Noncommutative Differential Forms on the kappa-deformed Space

We construct a differential algebra of forms on the kappa-deformed space. For a given realization of the noncommutative coordinates as formal power series in the Weyl algebra we find an infinite family of one-forms and nilpotent exterior derivatives. We derive explicit expressions for the exterior derivative and one-forms in covariant and noncovariant realizations. We also introduce higher-order forms and show that the exterior derivative satisfies the graded Leibniz rule. The differential forms are generally not graded-commutative, but they satisfy the graded Jacobi identity. We also consider the star-product of classical differential forms. The star-product is well-defined if the commutator between the noncommutative coordinates and one-forms is closed in the space of one-forms alone. In addition, we show that in certain realizations the exterior derivative acting on the star-product satisfies the undeformed Leibniz rule.Comment: to appear in J. Phys. A: Math. Theo