Refined multilayered beam, plate and shell elements based on Jacobi polynomials

In this paper, theories of structures based on hierarchical Jacobi expansions are explored for the static analysis of multilayered beams, plates and shells. They belong to the family of classical orthogonal polynomials. This expansion is employed in the framework of the Carrera Unified Formulation (CUF), which allows to generate finite element stiffness matrices in a straightforward way. CUF allows also to employ both layer-wise and equivalent single layer approaches in order to obtain the desired degree of precision and computational cost. In this work, CUF is exploited for the analysis of one-dimensional beams and two-dimensional plates and shells, and several case studies from the literature are analysed. Displacements, in-plane, transverse and shear stresses are shown. In particular, for some benchmarks, the shear stresses are calculated using the constitutive relations and the stress recovery technique. The obtained results clearly show the convenience of using equivalent single layer models when calculating displacements, in-plane stresses and shear stresses recovered by three-dimensional indefinite equilibrium equations. On the other hand, layer-wise models are able to accurately predict the structural behaviour, even though higher degrees of freedom are needed

Use of Lagrange polynomials to build refined theories for laminated beams, plates and shells

This paper proposes an equivalent single-layer approach for modeling laminated structures, where the number layers to be considered as a single one is chosen a priori by the user. Lagrange points are set to locate and, eventually, join equivalent single-layer and layer-wise tenchiques by imposing displacement continuity in the thickness direction. The Finite Element (FE) method is applied to provide numerical solutions whereas the Carrera Unified Formulation (CUF) is used to generate the related stiffness matrices in a compact and straightforward way. The approach is employed using one-dimensional beam and two-dimensional plate and shell models and several case studies, taken from well-known examples in the literature, are analyzed. Results clearly show the advantages and superiority of the present approach to completely capture the displacements and the distribution of the axial stress components, whereas local values of the shear stresses can be obtained by opportunely chosing the Lagrange points pattern opportunely

Evaluation of transverse shear stresses in layered beams/plates/shells via stress recovery accounting for various CUF-based theories

This paper exploits the stress recovery technique to evaluate the out-of-plane stress components in the static analysis of composite beams, plates and shells. This technique is implemented in the framework of the Carrera Unified Formulation, an approach allowing the implementation of the theories of structures in a compact way. This work uses Taylor, Legendre and Jacobi polynomials with equivalent single-layer and layer-wise approaches. The finite element method is applied to provide numerical solutions. Multi-layered beams, plates and shells subjected to different loading and boundary conditions are studied to validate and assess the proposed technique. The results are compared with those from the literature and show that the stress recovery technique provides reasonable accuracy for the shear stresses, even with lower-order models. Furthermore, results confirm that, when dealing with thick structures, the adoption of layer-wise models is mandatory to obtain accurate results

Determination of Pesticide Residues in IV Range Artichoke (Cynara cardunculus L.) and Its Industrial Wastes

Fourth-range products are those types of fresh fruit and vegetables that are ready for raw consumption or after cooking, and belong to organic or integrated cultivations. These products are subject to mild post-harvesting processing procedures (selection, sorting, husking, cutting, and washing), and are afterwards packaged in packets or closed food plates, with an average shelf life of 5–10 days. Artichokes are stripped of the leaves, stems and outer bracts, and the remaining heads are washed with acidifying solutions. The A LC-MS/MS analytical method was developed and validated following SANTE guidelines for the detection of 220 pesticides. This work evaluated the distribution of pesticide residues among the fraction of artichokes obtained during the industrial processing, and the residues of their wastes left on the field were also investigated. The results showed quantifiable residues of one herbicide (pendimethalin) and four fungicides (azoxystrobin, propyzamide, tebuconazole, and pyraclostrobin). Pendimethalin was found in all samples, with the higher values in leaves 0.046 ± 8.2 mg/kg and in field waste 0.30 ± 6.7 mg/kg. Azoxystrobin was the most concentrated in the outer bracts (0.18 ± 2.9 mg/kg). The outer bracts showed the highest number of residues. The industrial waste showed a significant decrease in the number of residues and their concentration

The effect of the relative amount of ingredients on the rheological properties of semolina doughs

"Pani carasau" is a traditional Sardinian bread, made with re-milled durum wheat semolina, with a long shelf-life. The production process is highly energy consuming, but its automation can make it more energy-efficient and sustainable. This requires a deep knowledge of the rheological parameters of the doughs. This study investigated the rheological properties of doughs-prepared by mixing semolina with water, yeast, and salt-as a function of the relative amount of the ingredients. The rheological measurements were carried out by an Anton Paar MCR 102 rheometer, equipped with a plate-plate fixture. In more detail, frequency sweep and creep tests were performed. It was found that doughs obtained with different amounts of ingredients showed significant differences in the rheological responses. The addition of water led to a significant decrease in the viscosity and improved the deformability of the dough. In addition, the yeast addition produced a viscosity decrease, while the presence of salt produced an improvement of the three-dimensional gluten network characteristics and, consequently, of the strength of the dough. In addition to the production process of pani carasau, this work contributes to improving the general performance of the doughs used in the production of flour-and-semolina-based foods

Coordinating Pluggable Transceiver Control in SONiC-based Disaggregated Packet-Optical Networks

Effective control of pluggable transceivers in SONiC-based packet-optical nodes is demonstrated. A workflow for multi-layer recovery upon soft failure detection is validated, showing no traffic disruption and fast node-driven coordination between packet and optical operations

Screening, Genetic Variants, and Bipolar Disorders: Can Useful Hypotheses Arise from the Sum of Partial Failures?

Bipolar disorder (BD) is a relevant public health issue, therefore accurate screening tools could be useful. The objective of this study is to verify the accuracy of the Mood Disorder Questionnaire (MDQ) and genetic risk as screeners, and their comparison in terms of reliability. Older adults (N = 61, ≥60 years) received a clinical psychiatric evaluation, the MDQ, and were evaluated according to the presence of the genetic variant RS1006737 of CACNA1C. MDQ+ versus the diagnosis of BD as a gold standard shows a sensitivity of 0.286 (Cl 95% 0.14–0.39); a specificity of 0.925 (Cl 95% 0.85–0.08); a predictive positive value (PPV) of 0.667 (Cl 95% 0.33–0.91); and a predictive negative value (PNV) of 0.702 (Cl 95% 0.65–0.75). The positivity for the variant RS1006737 of the CACNA1C against the diagnosis of BD as a gold standard shows a sensitivity of 0.750 (Cl 95% 0.55–0.90); a specificity of 0.375 (Cl 95% 0.28–0.45); a PPV of 0.375 (Cl 95% 0.28–0.45); and a PNV of 0.750 (Cl 95% 0.55–0.90). The reliability between the MDQ+ and positivity for the variant RS1006737 of the CACNA1C was very low (K = −0.048, Cl 95% −0.20–0.09). The study found that both the genetic and the paper and pencil test were quite accurate, but were not reliable in case finding. In fact, despite some validity, albeit specular (in the case of a positive genetic test, the probability of having the disorder is very high, whereas in the case of a negative score on the paper and pencil test, the probability of not having the disorder is very high), the unreliability of the two tests (i.e., they certainly do not measure the same underlying dimension) opens the door to the need for an interpretation and the possibility of a synergistic use for screening. From a heuristic perspective, which obviously requires all of the necessary verifications, this study seems to suggest the hypothesis that a condition of hyperactivation common to disorders and stress conditions, and identified by a positive score on the MDQ (which is common to BD, post-traumatic stress disorder (PTSD), and anxiety disorders and whose genetic basis has not yet been clarified) can trigger BD in people with a predisposition to hyperactivity (i.e., in people with the condition identified by the analyzed genetic variant)

Mechanical correlates of dyspnea in bronchial asthma.

We hypothesized that dyspnea and its descriptors, that is, chest tightness, inspiratory effort, unrewarded inspiration, and expiratory difficulty in asthma reflect different mechanisms of airflow obstruction and their perception varies with the severity of bronchoconstriction. Eighty-three asthmatics were studied before and after inhalation of methacholine doses decreasing the 1-sec forced expiratory volume by ~15% (mild bronchoconstriction) and ~25% (moderate bronchoconstriction). Symptoms were examined as a function of changes in lung mechanics. Dyspnea increased with the severity of obstruction, mostly because of inspiratory effort and chest tightness. At mild bronchoconstriction, multivariate analysis showed that dyspnea was related to the increase in inspiratory resistance at 5 Hz (R 5) (r (2) = 0.10, P = 0.004), chest tightness to the decrease in maximal flow at 40% of control forced vital capacity, and the increase in R 5 at full lung inflation (r (2) = 0.15, P = 0.006), inspiratory effort to the temporal variability in R 5-19 (r (2) = 0.13, P = 0.003), and unrewarded inspiration to the recovery of R 5 after deep breath (r (2) = 0.07, P = 0.01). At moderate bronchoconstriction, multivariate analysis showed that dyspnea and inspiratory effort were related to the increase in temporal variability in inspiratory reactance at 5 Hz (X 5) (r (2) = 0.12, P = 0.04 and r (2) = 0.18, P < 0.001, respectively), and unrewarded inspiration to the decrease in X 5 at maximum lung inflation (r (2) = 0.07, P = 0.04). We conclude that symptom perception is partly explained by indexes of airway narrowing and loss of bronchodilatation with deep breath at low levels of bronchoconstriction, but by markers of ventilation heterogeneity and lung volume recruitment when bronchoconstriction becomes more severe

Infectious agents including COVID-19 and the involvement of blood coagulation and fibrinolysis. A narrative review

Platelets, blood coagulation along with fibrinolysis are greatly involved in the pathophysiology of infectious diseases induced by bacteria, parasites and virus. This phenomenon is not surprising since both the innate immunity and the hemostatic systems are two ancestral mechanisms which closely cooperate favoring host's defense against foreign invaders. However, the excessive response of these systems may be dangerous for the host itself