This study focuses on the development of multi-material solutions for fire-resistant structural materials for transport and thermal insulation in the construction field. Special attention was paid to ...combining recyclable and bio-mass derived raw materials without interfering with an easy end-of-life separation, recycling and reuse. Fire-resistant biomass derived resins were associated with basalt derived Mineral Fibres (BDMF) in the form of prepregs, which were studied as semi-finished materials. Fire-resistance was obtained by associating these prepregs with thin gres tiles in the case of fire-resistant thermal insulating facades and with aluminum layers (giving origin to Fibre Metal Laminates-FML) in the case of structural components for transport applications. Thermophysical characterization of the solutions was carried out to assess both thermal conductivity and thermal diffusivity. Fire resistance tests were performed on FML to determine the number of Al layers needed to ensure fire resistance. Results suggest that fire resistance depends primarily on the number of Al layers, rather than on their thickness. Accelerated ageing tests (salty mist and freeze-thaw) were executed to predict durability in the expected working conditions. Results suggest a durability issue in FML with preceramic interface in salty environments.
Mortar-based reinforcements are an innovative solution for retrofitting existing structures that combine effectiveness, compatibility, and sustainability. Despite the recent spreading of field ...applications, there is still insufficient knowledge on their fundamental mechanical properties, and a regulatory gap for experimental procedures and design criteria. A Round Robin Test initiative was organized by the Rilem TC 250-CSM (Composites for the Sustainable strengthening of Masonry) to investigate the tensile and bond behaviour of mortar-based composites with basalt, carbon, glass, polyparaphenylene benzobisoxazole (PBO), aramid and steel textiles. This paper presents the tests carried out on Steel Reinforced Grout (SRG) systems, comprising three textile and four mortar types, supplied by three producers. Ten laboratories from Italy, Poland and Portugal were involved for a total of 150 tests, including direct tensile tests on textiles and composites, and single-lap bond tests on masonry substrate. The influence of the layout of the textile, the mechanical properties of the mortar matrix, the manufacturing and curing conditions, as well as the testing setup and instrumentation, is discussed to contribute to the optimization of the reinforcement systems and to the development of recommendations for laboratory testing. Finally, results are combined to derive engineering parameters for qualification and design purposes.
An increasing interest and application is nowadays found for composite systems in construction and rehabilitation industry. The consensus on fibre reinforced composite systems was mainly based on ...high tensile strength, light weight, relative ease of installation, and resistance to corrosion. However, some drawbacks related to the epoxy (hence, organic) matrices of Fiber-Reinforced Polymers (FRP) have been solved by inorganic ones yielding to novel fibre reinforced composites. In these materials the composite action is mainly achieved through mechanical interlock between the matrix (e.g. a cement- or a lime-based mortar or a geopolymer with the option of chopped fibres and/or low-content polymer addition) and the mesh-like fibrous structure (a textile) that allows the mortar to protrude through the grid's openings. Aiming at the investigation of the mechanical properties and the development of testing procedures for this new family of materials (termed herein as Fabric-Reinforced Cementitious Matrix (FRCM)) the present paper presents the results of an extensive experimental program on different combinations of basalt fibre textiles and inorganic matrices organized by RILEM TC 250-CSM (Composites for the Sustainable strengthening of Masonry) involving ten European laboratories. The tests involve more than 100 specimens: half are tensile tests and the other half are bond tests carried out on prisms made of clay bricks, on three different basalt-based FRCM configurations comprising readily available commercial systems provided by different producers. The scope of this work is aimed not only at presenting a comparative performance assessment of different Basalt FRCM systems, but also at providing meaningful criteria to reliably design and analyse retrofit applications. The relevant round robin test program provides valuable data generated during the experimental activity and statistical analysis thereof; then, based on the various testing approaches employed, the advantages/drawbacks of certain testing factors are summarized and critically assessed, reflecting the experience of involved institutions. It is believed that this represents a crucial step in improving knowledge on innovative retrofit applications and developing standard test methods.
Abstract This paper reports the activities carried out under project FENICE (Upscaling, KAVA 9, EIT Raw Materials, www.Fenice-composites.eu, 2022-2025) about improving fire resistance of electric ...cars batteries, in particular through the development of Fiber Metal Laminates (FML) battery boxes. The aim of this study is to analyse the corrosion behaviour of FML based on bio-based and closed loop recyclable prepregs, in typical ageing conditions (thermal ageing, neutral and cupric acetic salt spray). FML degradation, evaluated in term of residual tensile strength after ageing, along with surface corrosion is remarkably low, and also resistance to humid environment seems satisfactory. However proper inorganic surface finishing is needed, since otherwise typical automotive tests, such as salty spray chamber ageing, cannot be passed in term of corrosion resistance requirements. The project is studying surface vitrification with sol-gel formulations, since traditional painting, based on organic polymers could ensure aluminium corrosion resistance, but would inevitably decrease fire resistance, while Cr-plating is not environmentally friendly, because of its higher carbon footprint and since it would make direct aluminium recyclability impossible, so. These advanced treatments were, up to now, not compatible with the adoption in the mass production, but things are rapidly changing, following the green transition that is currently bringing a number of small revolutions in the manufacturing sector.
Mineral inclusions entrapped in other minerals may record the local stresses at the moment of their entrapment in the deep Earth. When rocks are exhumed to the surface of the Earth, residual stresses ...and strains may still be preserved in the inclusion. If measured and interpreted correctly through elastic geobarometry, they give us invaluable information on the pressures (P) and temperatures (T) of metamorphism. Current estimates of P and T of entrapment rely on simplified models that assumes that the inclusion is spherical and embedded in an infinite host, and that their elastic properties are isotropic. We report a new method for elastic geobarometry for anisotropic inclusions in quasi-isotropic hosts. The change of strain in the inclusion is modelled with the axial equations of state of the host and the inclusion. Their elastic interaction is accounted for by introducing a 4th rank tensor, the relaxation tensor, that can be evaluated numerically for any symmetry of the host and the inclusion and for any geometry of the system. This approach can be used to predict the residual strain/stress state developed in an inclusion after exhumation from known entrapment conditions, or to estimate the entrapment conditions from the residual strain measured in real inclusions. In general, anisotropic strain and stress states are developed in non-cubic mineral inclusions such as quartz and zircon, with deviatoric stresses typically limited to few kbars. For garnet hosts, the effect of the mutual crystallographic orientation between the host and the inclusion on the residual strain and stress is negligible when the inclusion is spherical and isolated. Assuming external hydrostatic conditions, our results suggest that the isotropic and the new anisotropic models give estimations of entrapment conditions within 2%.
•Elastic geobarometry is extended to include the elastic anisotropy of minerals.•P and T of entrapment can be determined from the strains in one inclusion.•Effects of anisotropy on spherical inclusions in cubic host minerals are small.•Non-hydrostatic stress can be detected during metamorphism.
Systemic sclerosis (SSc) is burdened by Raynaud phenomenon (RP) and digital ulcers (DUs), and sometimes standard vasoactive therapies are ineffective or contraindicated. Selexipag is an oral ...selective IP prostacyclin receptor agonist approved for the treatment of SSc-related pulmonary arterial hypertension. We aimed to evaluate the clinical and instrumental efficacy of selexipag in SSc digital vasculopathy.
Patients with SSc with severe digital vasculopathy refractory or with contraindication to all other vasoactive therapies were administered selexipag. RP- and DU-related clinical outcomes were evaluated, and digital perfusion was assessed by laser speckle contrast analysis (LASCA), all at baseline and after 3 months.
Selexipag was administered to 9 patients with SSc (66.6% female, mean age 52.3 SD 16.6 yrs). One patient had to stop the drug because of adverse effects. After 3 months of selexipag administration, there was a significant reduction in RP daily episodes (
= 0.01) and RP mean duration (
= 0.04). The number of DUs decreased from 10 to 4 without reaching statistical significance. A significant improvement in mean perfusion of the fingers (
= 0.02) was observed with LASCA.
Selexipag showed good potential for the treatment of SSc digital vasculopathy. Our results are certainly preliminary, yet quite encouraging. New trials for the evaluation of selexipag efficacy in SSc digital vasculopathy are needed.
To evaluate finger proximal-distal gradient (PDG) perfusion in subjects with primary Raynaud's phenomenon (PRP), then making comparisons with systemic sclerosis (SSc) patients and healthy controls ...(HC).
Consecutive adult PRP subjects were enrolled, along with an equal number of SSc and HC. Peripheral blood perfusion of the hands was assessed by laser speckle contrast analysis (LASCA). PDG was then calculated applying a generalizable formula independent of both intra- and inter-personal factors. Non-specific anti-nuclear autoantibody (ANA) isolated positivity was assessed.
Fifty PRP patients (88 % female, mean age 45 ± 17.9 years) were enrolled, along with 50 SSc patients and 50 HC. After adjusting mean PDG results for age and sex, no significant differences emerged between PRP and SSc (1.80 ± 0.43 vs 1.76 ± 0.53; p = 0.294). Conversely, PRP values were significantly reduced when compared to HC (2.72 ± 0.37; p < 0.001). Among PRP subjects, no significant differences were found regarding isolated ANA positivity (1.86 ± 0.44 vs 1.74 ± 0.44; p = 0.42).
PRP and SSc seems to share the same basal PDG perfusion impairment assessed by LASCA. Isolated ANA positivity, in the absence of clinical and capillaroscopic suspicion for secondary causes, should not be considered an exclusion criterion for PRP classification.
•Proximal-distal gradient perfusion is reduced in primary Raynaud's phenomenon (PRP).•PRP and systemic sclerosis share the same proximal-distal gradient impairment.•PRP criteria could also include non-specific isolated ANA positivity.
ABSTRACT
We present a study of the 1173 sources brighter than $S_{1.4\, \rm GHz}= 120\, \mu$Jy detected over an area of $\simeq 1.4\, \hbox{deg}^{2}$ in the Lockman Hole field. Exploiting the ...multiband information available in this field for ∼79 per cent of the sample, sources have been classified into radio loud (RL) active galactic nuclei (AGNs), star-forming galaxies (SFGs), and radio quiet (RQ) AGNs, using a variety of diagnostics available in the literature. Exploiting the observed tight anticorrelations between IRAC band 1 or band 2 and the source redshift we could assign a redshift to 177 sources missing a spectroscopic measurement or a reliable photometric estimate. A Monte Carlo approach was used to take into account the spread around the mean relation. The derived differential number counts and luminosity functions at several redshifts of each population show a good consistency with models and with earlier estimates made using data from different surveys and applying different approaches. Our results confirm that below $\sim 300\, \mu$Jy SFGs+RQ AGNs overtake RL AGNs that dominate at brighter flux densities. We also confirm earlier indications of a similar evolution of RQ AGNs and SFGs. Finally, we discuss the angular correlation function of our sources and highlight its sensitivity to the criteria used for the classification.
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