196,148 research outputs found
COVID-19 pandemic and rehabilitation: How protective is social isolation in the care of frail patients (and their caregivers)?
No full textGuidelines for the anatomopathological diagnosis of chronic idiopathic inflammatory bowel disease
No full textSkorohod-Olevsky Viscous Sintering Model Sensitivity to Temperature Distribution During the Sintering Process
No full textThis paper investigates the influence of temperature field non-uniformity on sintering simulation results using the Skorohod-Olevsky viscous sintering model. As a difference to previous studies, here a thermal transient analysis is performed to provide a detailed temperature field over the component within sintering time. Results obtained using uniform temperature distribution are compared to those obtained using a non-uniform distribution derived from a transient thermal analysis. Results are compared for different geometry sizes, that lead to different temperature non-uniformity levels. The study has shown that the temperature non-uniformity cannot always be neglected and should be considered as a possible source of modeling error
Sectional homogenization with a general nonlinear constitutive law for corrugated board analysis
No full textCorrugated board is widely used in packaging applications due to its favorable mechanical properties and cost-effectiveness. This study proposes a two-step, multiscale, sectional homogenization approach to determine the effective elastic parameters and predict the mechanical behavior of cardboard under various loading conditions. In the first step, a representative 3D periodic model of corrugated board is developed to extract its effective elastic properties. This homogenization process reduces the complex 3D structure to a simplified 2D shell model. The second step focuses on computing deformations, strains, and stresses in cardboard structures. Instead of using a conventional plastic constitutive model, the 3D Representative Volume Element (RVE) model is employed. Strains from the 2D model are applied as boundary conditions to the 3D RVE, where corresponding stresses are determined based on pre-calibrated strain-stress relationships obtained from uniaxial tests. Stiffness degradation is captured, from a computational viewpoint, at Gauss points in the 2D model. The results demonstrate that the proposed approach accurately reproduces the real mechanical behavior of cardboard while utilizing a simplified 2D model
How do children make sense of peace and war? An exploratory study through the drawings of Italian pupils with an indirect experience of the war in Ukraine
No full textThe indirect exposure to war could have an impact on children's construction of meaning about peace and war. The study investigates Italian children's representations of peace and war by observing the contents and expressive connotations of their drawings, and the possible influences of the conflict in Ukraine. Drawings of peace and war of 38 children (M = 9.43, SD = 1.47) were collected in Italy in the Spring of 2022 after the beginning of the war in Ukraine. Parents answered a socio-demographical questionnaire, including information about family indirect experience of war. According to previous literature, peace images resulted as positive actions or absence of war, and war images are typical objects and activities of war. In contrast to the negative connotation of war drawings, peace drawings were more colored and convey a positive expressivity. The majority of children began by representing peace and included few people in both drawings. The frequencies of references to the war in Ukraine are not high, even if the majority of children talked about war with their parents after the beginning of the war in Ukraine. Educational implications of understanding the representations of peace and war in children with indirect exposure to conflicts are discussed
A numerical model of capsulorhexis to assess the relevance of size and position of the rhexis on the IOL decentering and tilt
No full textFinite element simulations of the mechanical stability of a post-cataract capsular bag demonstrate that a decentered and non-circular rhexis does not induce appreciable IOL decentering and tilt.
Finite element models of human crystalline capsular bag and zonular fibers are used to estimate the mechanical response of the capsule to the presence of a C-loop Intra-Ocular Lens (IOL) after cataract surgery, to assess the influence of capsulorhexis size, shape and location on IOL decentration and tilt. The model includes, in the anterior capsule, a hole with variable size, shape and position, which represents the rhexis obtained in a manual or laser-assisted manner. The IOL is not explicitly modelled, but its action is reproduced by means of a set of elastic ties, connecting the opposite sides of the bag and exerting the force corresponding to an expanded IOL. Numerical simulations show that IOL decentration and tilt are not related to the size of the rhexis. A decentered rhexis induces IOL decentration <40 μm and a tilt <12°; the combination of non-circular shape and decentering of the rhexis induces IOL decentration <47 μm. While the introduction of a circular central rhexis causes an increment of the stresses in the capsule up to 100% relative to the physiological state, the combination of rhexis decentering and non-circular shape causes an additional 10% stress change. The values of IOL decentering and IOL tilt obtained from simulations are of scarce relevance in the clinical practice
Optimised structural modelling for inverse analysis parameter identification relying on dynamic measurements.
No full textIn the context of Inverse Analysis in Civil Engineering, parameter identification and
model calibration, of a structural system, relying on dynamic measurements, are subjects of a
growing research interest. In the present contribution, the topic is tackled with reference both
to simplified structural numerical examples and to a specific case study, namely a historical
road three-span reinforced concrete arched bridge, with vibrational data previously acquired
by standard wired accelerometers on the deck, under operational traffic conditions. In particular, the present work aims at focussing on the identification issues, concerning the definition of a maximum allowable threshold number of sought material parameters (e.g., Young’s moduli and mass densities of different structural components), with respect to the amount of available measurement data, and the investigation of the inverse analysis discrepancy function to be optimised, in order to set the intrinsic issue of multiple “realizations”, in case of a plain use of modal properties, and in view of forming a well–posed optimisation problem. Structural modelling, sensitivity analysis and numerical optimisation approaches are herein combined toward a robust and efficient identification strategy, to be effectively employed in structural assessment and diagnosis, also with respect to originally available or enriched sets of experimental data.
The proposed methodology, and collected results, shall outline an efficient identification procedure, in view of automated inverse analysis, practically oriented to the dynamic assessment and structural diagnosis in the Civil Engineering context, as applied e.g. to strategic bridge infrastructures
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