Textile Reinforced Mortar (TRM) composite systems have recently been developed using environmentally sustainable binders, including alkali-activated mortars (AAMs). Despite their promising mechanical performance and reduced environmental impact, the feasibility of incorporating AAMs into TRM strengthening systems has not yet been fully established. In particular, the behaviour of AAM-based TRM composites, known as TRAAMs, under elevated temperatures remains poorly understood, and limited experimental evidence is currently available regarding their mechanical stability, bond performance, and failure mechanisms after thermal exposure. This study investigates and compares the performance of TRM systems manufactured with different binders (lime, cement, and alkali-activated) reinforced with coated basalt textiles, both at room temperature (20 degrees C) and after exposure to elevated temperatures (200 degrees C, 400 degrees C, and 600 degrees C). Residual properties were assessed through mechanical testing and microstructural analyses. Furthermore, the results were benchmarked against data available in the literature for comparable TRM systems subjected to high temperatures. The findings indicate that exposure up to 200 degrees C has a negligible influence on the TRM residual performance, with TRAAM systems even showing slight improvements. Conversely, exposure to 400 degrees C and above leads to a significant degradation of performance in all TRM systems.
Objectives: This study aimed to assess stroke coordination and biomechanics in elite U23 male kayakers under valid on-water conditions (instrumented K1 kayak on a competition lake) across race-relevant stroke frequencies (60, 80, and 100 strokes & centerdot;min(-1)). Methods: To achieve our aims, twelve male athletes (age 21.00 +/- 0.47 years) completed 500 m trials at three randomized paddle frequencies (60, 80, 100 strokes & centerdot;min(-1)) with 10 min of passive recovery in-between. Data were collected with inertial measurement units, and a customized seat/footrest with integrated strain-gauge sensors. Results: Principal Component Analysis identified four key components: Mechanical Work, Mechanical Energy, Stroke Variability (PCI, Phase Coordination Index), and boat acceleration, accounting for 76% of total variance. Linear mixed-effects models (within-subject LME; Participant random intercept; Satterthwaite df) revealed that Mechanical Work (chi(2) = 17.10, p < 0.001) and Mechanical Energy (chi(2) = 53.10, p < 0.001) increased significantly with stroke frequency. Phase Coordination Index showed a significant increase at 60 and 100 strokes & centerdot;min(-1) (chi(2) = 16.78, p < 0.001; t = 4.78, p < 0.001), while boat acceleration was not significantly affected (chi(2) = 4.95, p = 0.08). The PCI correlated negatively with Mechanical Work (r = -0.37, p = 0.022) and positively with boat acceleration (r = 0.39, p = 0.010). Effect sizes were moderate to large (eta p(2) = 0.18-0.36; corresponding 95% confidence intervals are reported in the main text). For the primary mechanical indicator (Paddle Factor), the mixed-effects model yielded a marginal R-2 = 0.57, reflecting the proportion of variance explained by cadence. Conclusions: Approximately 80 strokes & centerdot;min(-1) may represent a condition in which coordination metrics appear comparatively favorable. These findings are exploratory and hypothesis-generating, not prescriptive. No causal inference can be drawn, and any training application attempts should await replication in larger, longitudinal and randomized studies.
We consider a Large Eddy Simulation (LES) model for an incompressible Newtonian fluid in a box-shaped domain with periodic boundary conditions on the lateral boundaries and homogeneous Dirichlet conditions on the top and bottom. The model is obtained through the application of an anisotropic horizontal filter, defined as the inverse of the corresponding Helmholtz operator. The existence of global “regular weak solutions” for this model is already known [9]. Here, we study the associated dynamics and we show, with elementary methods, the existence of the global attractor in a suitable phase space. This extends the analysis provided in [17].
La sarcopenia è sempre più riconosciuta per i suoi effetti negativi sullo stato funzionale e sulla qualità della vita, spesso associati a disfunzioni metaboliche e ormonali. Queste condizioni possono anche avere un impatto negativo sulla salute sessuale. La letteratura valutata è costituita principalmente da studi trasversali condotti su uomini con età avanzata, ad eccezione di una ricerca che ha riportato una forte associazione tra sarcopenia (o le sue componenti) e disfunzioni sessuali, in particolare la disfunzione erettile. Tuttavia, la significativa eterogeneità dei criteri diagnostici e il numero limitato di studi incentrati sulle donne portano a risultati non conclusivi. Sono necessari ulteriori studi longitudinali con coorti più ampie e criteri di valutazione standardizzati per chiarire i meccanismi sottostanti, stabilire relazioni causali e sviluppare interventi su misura per un trattamento ottimale. Infine, questa rassegna sottolinea la necessità di approfondire tale tematica nelle donne.
The creep response of AISI 316L austenitic stainless steel produced by additive manufacturing has garnered considerable attention in recent years. This interest stems from the unique microstructure created by the exceptionally high cooling rates characteristic of this technology. Despite numerous studies addressing this issue, the constitutive analysis of the relationships between temperature, stress, and creep response has predominantly relied on traditional phenomenological models, which do not facilitate an easy quantitative correlation with microstructural features. The primary objective of this study was to bridge this knowledge gap by proposing a physically based constitutive model that elucidates the unique dependence of the minimum creep rate on applied stress and temperature in AISI 316L steels manufactured through additive processes. The short-term creep behavior of AISI 316L stainless steel fabricated by the laser powder bed fusion additive manufacturing technology was investigated at 600 and 650 °C, using constant load and variable load experiments. The microstructure was characterized by transmission electron microscopy; fracture analysis was performed on crept samples by scanning electron microscopy. Creep response was compared to literature concerning other 316L stainless steel samples fabricated by the same additive manufacturing technology and to conventional wrought steels having a similar composition. Results showed comparable time to ruptures, although the steel investigated in the present study showed much lower (one order of magnitude) minimum creep rates. The microstructural results suggested assimilating the steel to a purposedly developed simplified model-material. Combination with available constitutive models confirmed the strong relationship between creep behavior and microstructural features.
