Structural validation of a realistic wing structure: the RIBES test article

Several experimental test cases are available in literature to study and validate fluid structure interaction methods. They, however, focus the attention mainly on replicating typical cruising aerodynamic conditions forcing the adoption of fully steel made models able to operate with the high loads generated in high speed facilities. This translates in a complete loss of similitude with typical realistic aeronautical wing structures configurations. To reverse this trend, and to better study the aerolastic mechanism from a structural point of view, an aeroelastic measurement campaign was carried within the EU RIBES project. A half wing model for wind tunnel tests was designed and manufactured replicating a typical metallic wing box structure, producing a database of loads, pressure, stress and deformation measurements. In this paper the design, manufacturing and validation activities performed within the RIBES project are described, with a focus on the structural behavior of the test article. All experimental data and numerical models are made freely available to the scientific community

Radial basis functions mesh morphing for the analysis of cracks propagation

Abstract Damage tolerant design requires the implementation of effective tools for fracture mechanics analysis suitable for complex shaped components. FEM methods are very well consolidated in this field and reliable procedures for the strength assessment of cracked parts are daily used in many industrial fields. Nevertheless the generation of the computational grid of the cracked part and its update after a certain evolution are still a challenging part of the computational workflow. Mesh morphing, that consists in the repositioning of nodal locations without changing the topology of the mesh, can be a meaningful answer to this problem as it allows the mesh updating without the need of rebuilding it from scratch. Fast Radial Basis Functions (RBF) can be used as an effective tool for enabling mesh morphing on very large meshes that are typically used in advanced industrial applications (many millions of nodes). The applicability of this concept is demonstrated in this paper exploiting state of the art tools for FEA (ANSYS Mechanical) and for advanced mesh morphing (RBF Morph ACT Extension). Proposed method is benchmarked using as a reference a circular notched bar with a surface defect. Reliability of fracture parameter extraction on the morphed mesh is first verified using as a reference literature data and ANSYS Mechanical tools based on re-meshing: different crack shapes are achieved using the new geometry as a morphing target. Crack propagation workflow is then demonstrated showing the computed shape evolution for different size and shape of the initial crack

Users' participation in facebook brand pages and its influence on word-of-mouth: the role of brand knowledge and brand relationship

Due to the development of social media, brands have integrated Social Networking Sites (SNS) as an important part of their communication mix. This change calls for studies that help to understand the role of SNS in the communication mix, through further investigating their effects for brands and acknowledging their influencing triggers. Concerning that, previous studies have associated the use of SNS to effects on WoM, with SNS contributing as a tool skilled for generating conversations about the brand. The current study focuses on investigating the triggers of these effects. In previous research, WoM was accepted as being triggered by constructs related to the effects of SNS on increasing users´ knowledge about the brand and improving perceived relationship value. Despite their relevance, studies in SNS so far have not yet explored these approaches in an integrative manner. So researchers and managers could understand how these dimensions behave in relation to each other in triggering WoM. The current study addresses this research gap, proposing an integrative perspective that combines brand knowledge and brand relationship constructs while investigating the effects on WoM. Direct and indirect effects are proposed with mediating relations being supported by the Theory of Reason Action (TRA) and Social Exchange (SET). Two surveys were implemented, with 218 and 550 valid responses obtained. Results were analyzed using structural equation modeling. Findings support the relevance of brand relationship variables (trust and affective commitment) in influencing WoM, with trust assuming a pivotal role. Moreover, triggers related to brand knowledge also influence the effects, with brand awareness and attitude driving significant effects. Managerial and theoretical implications are discussedinfo:eu-repo/semantics/publishedVersio

Retroperitoneal pararenal isolated neurofibroma: report of a case and review of literature

The neurofibroma is a tumour of neural origin. This kind of neoplasm, though, is generally skin located. Rare cases in deep organs or in the peritoneal cavity are also reported in the literature. There are two types of neurofibromas, localized and diffuse; the latter is associated with von Recklinghausen disease and always occurs together with skin neurofibromas. Here we report the case of a 47-year-old man affected by retroperitoneal neurofibroma, but not associated with von Recklinghausen disease. A computed tomography (CT) scan described a retroperitoneal pararenal lesion with no clear involvement of adjacent viscera. We describe the diagnostic modality, treatment planning and the timing of treatment of this neoplasm, reviewing also the literature

Comparison of numerical models for Acoustic Emission propagation

Abstract Acoustic Emissions (AE) are at the basis of extremely accurate and reliable monitoring systems. Within the SmartBench project, data regarding structural health of components are gathered in a database in order to make safety integrated, operative and smart. An accurate modelling of wave propagation is a necessary requirement for a proper design of sensor networks as well as for data interpretation. Numerical simulations of the transient behavior of structural systems are well-established in this field but, on the minus side, they are very expensive in terms of computational time and resources. This paper reports different instances of AE propagation through metallic media. Bulk waves and guided waves are both investigated by means of 2D and 3D models and resorting to different software. Obtained results are cross-checked and computational times are compared as well. As a last point, High Performance Computing is applied to the case of waves simulation in order to get a significant reduction of the required computational time

Mechanical analysis of the ENEA TF coil proposal for the EU DEMO fusion reactor

The design of the superconducting magnet system of the European DEMO fusion reactor is currently being pursued in the framework of the EUROfusion Magnets Work Package (WPMAG). Three alternative winding pack (WP) options for the Toroidal Field Coils (TFCs) are being proposed by different research units, each featuring a different conductor manufacturing technology (react-and-wind vs. wind-and-react) or winding layout (layer vs. pancake). One of the options (namely, WP#2), proposed by Italian ENEA, features a layer-wound WP design adopting a wind-and-react conductor with rectangular cross section with high aspect ratio, obtained squeezing an initially circular conductor. In order to assess the capability of all the TFC components to withstand the electromagnetic loads due to the huge Lorentz forces without any structural failure during the magnet lifetime, the mechanical analysis of the 2016 version of the WP#2 design option is performed here applying a hierarchical approach herein defined as the Stress Recovery Tool (SRT): the Finite Element Analysis (FEA) of a whole magnet (including the casing) is performed at a low computational cost adopting a coarse WP model with smeared (homogenized) properties. The displacements computed on the smeared WP are then used as boundary conditions for a refined FEA of some WP slices, located in selected (critical) poloidal positions, where all the conductors detailed features (jacket, insulations) are properly accounted for

Surgical ‘damage control’ treatment of a large retroperitoneal liposarcoma encasing a horseshoe kidney

Damage control is a surgical strategy for severely compromised trauma patients based on speed control of life-threatening injuries that aims to rapidly resuscitate patients in an intensive care unit (ICU). We report on the use of such therapeutic strategy in a patient affected by a retroperitoneal sarcoma concomitant to a horseshoe kidney, a relatively rare anatomical malformation

Artificial intelligence weights the importance of factors predicting complete cytoreduction at secondary cytoreductive surgery for recurrent ovarian cancer

Objective: Accumulating evidence support that complete cytoreduction (CC) at the time of secondary cytoreductive surgery (SCS) improves survival in patients affected by recurrent ovarian cancer (ROC). Here, we aimed to determine whether artificial intelligence (AI) might be useful in weighting the importance of clinical variables predicting CC and survival. Methods: This is a retrospective study evaluating 194 patients having SCS for ROC. Using artificial neuronal network (ANN) analysis was estimated the importance of different variables, used in predicting CC and survival. ANN simulates a biological neuronal system. Like neurons, ANN acquires knowledge through a learning-phase process and allows weighting the importance of covariates, thus establishing how much a variable influences a multifactor phenomenon. Results: Overall, 82.9% of patients had CC at the time of SCS. Using ANN, we observed that the 3 main factors driving the ability of achieve CC included: disease-free interval (DFI) (importance: 0.231), retroperitoneal recurrence (importance: 0.178), residual disease at primary surgical treatment (importance: 0.138), and International Federation of Gynecology and Obstetrics (FIGO) stage at presentation (importance: 0.088). Looking at connections between different covariates and overall survival (OS), we observed that DFI is the most important variable influencing OS (importance: 0.306). Other important variables included: CC (importance: 0.217), and FIGO stage at presentation (importance: 0.100). Conclusion: According to our results, DFI should be considered as the most important factor predicting both CC and OS. Further studies are needed to estimate the clinical utility of AI in providing help in decision making process

Efficacy and fertility outcomes of levonorgestrel-releasing intra-uterine system treatment for patients with atypical complex hyperplasia or endometrial cancer: A retrospective study

Objective: To investigate the efficacy of levonorgestrel-releasing intra-uterine system (LNG-IUS) treatment in patients affected by atypical complex hyperplasia/endometrial cancer (ACH/EC) wishing to preserve their fertility and to present fertility outcomes of those patients who actively tried to conceive. Methods: Data of consecutive women with ACH/EC who underwent fertility-sparing treatment using LNG-IUS were retrospectively evaluated. Results: Overall, 48 patients and the mean (\ub1standard deviation) length of follow-up was 82.6\ub147.2 months. Among patients with ACH, 25/28 (89.3%) had a complete response (CR), 2/28 (7.1%) had a partial response (PR) and 1/28 (3.6%) had a progressive disease (PD). Mean (\ub1standard deviation) time to CR was 6.7\ub14.0 months. Among patients with G1 EC, 13/16 (81.3%) had a CR, 1/16 (6.3%) had a PR and 2/16 (12.5%) had a PD. Mean (\ub1standard deviation) time to CR was 5.0\ub12.9 months. Among patients with G2 EC, 3/4 (75.0%) had a CR and 1/4 (25.0%) had a PD. Mean (\ub1standard deviation) time to CR was 4.0\ub10 months. Only 19 (39.6%) patients who had CR actually attempted to conceive. Eleven (57.9%) women tried to conceive naturally while 8 (42.1%) women underwent an in vitro fertilization (IVF). Fourteen (73.7%) patients wishing to conceive achieved a pregnancy (6 spontaneously and 8 through IVF). Conclusions: Fertility-sparing treatment of patient with ACH/EC with LNG-IUS achieves high regression rates and good fertility outcomes. Future larger multi-institutional studies should be designed to confirm these preliminary findings