574 research outputs found
Understanding the relationships between tourists\u27 emotional experiences, perceived overall image, satisfaction, and intention to recommend
The purpose of this study is to empirically test an integrative model linking touristsâ emotional experiences, perceived overall image, satisfaction, and intention to recommend. The model was tested using data collected from domestic tourists visiting Sardinia, Italy. Results show that touristsâ emotional experiences act as antecedents of perceived overall image and satisfaction evaluations. In addition, overall image has a positive influence on tourist satisfaction and intention to recommend. The study expands current theorizations by examining the merits of emotions in tourist behavior models. From a practical perspective, the study offers important implications for destination marketers
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
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
Recent progress in the truncated Lanczos method : application to hole-doped spin ladders
The truncated Lanczos method using a variational scheme based on Hilbert
space reduction as well as a local basis change is re-examined. The energy is
extrapolated as a power law function of the Hamiltonian variance. This
systematic extrapolation procedure is tested quantitatively on the two-leg t-J
ladder with two holes. For this purpose, we have carried out calculations of
the spin gap and of the pair dispersion up to size 2x15.Comment: 5 pages, 4 included eps figures, submitted to Phys. Rev. B; revised
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An RBF Meshless Approach to Evaluate Strain Due to Large Displacements in Flexible Printed Circuit Boards
Thin plates are very often employed in a context of large displacements and rotations, for example, whenever the extreme flexibility of a body can replace the use of complicated kinematic pairs. This is the case of the flexible Printed Circuit Boards (PCBs) used, for example, within last-generation foldable laptops and consumer electronics products. In these applications, the range of motion is generally known in advance, and a simple strategy of stress assessment leaving out nonlinear numerical calculations appears feasible other than desirable. In this paper, Radial Basis Functions (RBFs) are used to represent a generic transformation of a bi-dimensional plate, with all the derivate fields being analytically achieved without the need for a numerical grid for large-displacement applications. Strains due to bending are easily retrieved with this method and satisfactorily compared to analytical and shell-based Finite Element Method (FEM) benchmarks. On the other hand, the computational costs of the juxtaposed methods appear far different; with the machine being equal, the orders of magnitude of the time elapsed in computation are seconds for the RBF-based strategy versus minutes for the FEM approach
Technique of sentinel lymph node biopsy and lymphatic mapping during laparoscopic colon resection for cancer
BACKGROUND: The utility of lymph node mapping to improve staging in colon cancer is still under evaluation. Laparoscopic colectomy for colon cancer has been validated in multi-centric trials. This study assessed the feasibility and technical aspects of lymph node mapping in laparoscopic colectomy for colon cancer.
METHODS: A total of 42 patients with histologically proven colon cancer were studied from January 2006 to September 2007. Exclusion criteria were: advanced disease (clinical stage III), rectal cancer, previous colon resection and contraindication to laparoscopy. Lymph-nodal status was assessed preoperatively by computed tomography (CT) scan and intra-operatively with the aid of laparoscopic ultrasound. Before resection, 2-3 ml of Patent Blue V dye was injected sub-serosally around the tumour. Coloured lymph nodes were marked as sentinel (SN) with metal clips or suture and laparoscopic colectomy with lymphadenectomy completed as normal. In case of failure of the intra-operative procedure, an ex vivo SN biopsy was performed on the colectomy specimen after resection.
RESULTS: A total number of 904 lymph nodes were examined, with a median number of 22 lymph nodes harvested per patient. The SN detection rate was 100%, an ex vivo lymph node mapping was necessary in four patients. Eleven (26.2%) patients had lymph-nodal metastases and in five (45.5%) of these patients, SN was the only positive lymph node. There were two (18.2%) false-negative SN. In three cases (7.1%) with aberrant lymphatic drainage, lymphadenectomy was extended. The accuracy of SN mapping was 95.2% and negative predictive value was 93.9%.
CONCLUSIONS: Laparoscopic lymphatic mapping and SN removal is feasible in laparoscopic colectomy for colon cancer. The ex vivo technique is useful as a salvage technique in case of failure of the intra-operative procedure. Prospective studies are justified to determine the real accuracy and false-negative rate of the technique
Cloud Manufacturing: state of the art and evaluation of the BaSyx project
The emergence of new technologies such as the Internet of Things (IoT) and Cloud Computing hasstrongly boosted the manufacturing industry, opening the doors to a much broader world ofpossibilities and starting what many consider to be the Fourth Industrial Revolution. In this context iswhere the manufacturing paradigm of Cloud Manufacturing (CMfg) emerges, with the goal to connectmanufacturing processes through the Cloud in such a way that it allows different organizations tocooperate and to offer services to customers that could not be possible by their own independently. Asystematic review of the literature was carried out in order to determine the main characteristics andfunctionalities that a CMfg system should provide as well as the main current lines of research in thisregard. Then, we developed a prototype CMfg system based on the open source middleware EclipseBaSyx, a software development kit for CMfg systems. The developed prototype consists of a webinterface module that allows different users to create new machines and to insert job orders from thecustomers, and a server logic module that is responsible for accepting jobs, dividing them intosubtasks and distributing them among the different machines that work independently from eachother. The web module is composed by three main sub-modules: 1) a scheduler to control anddistribute the orders among the different machines of the system; 2) a verifier, which is in charge ofmonitoring the state of the machines in the real time, collecting a large amount of information fromthem and notifying the scheduler in case of failures or when they need special attention; and 3) aBaSyx module that is in charge of the creation of the Digital Twins. Finally, several numericalexperiments were carried out to show the potential of BaSyx for leveraging different productionplanning and operations management problems that may arise under Cloud Manufacturingenvironments.Fil: Videla Helal, MatĂas Emiliano. Universidad de la RepĂșblica; UruguayFil: Chiappa Curbelo, Carlos S.. Universidad de la RepĂșblica; UruguayFil: Piñeyro, Pedro. Universidad de la RepĂșblica; UruguayFil: Viana, VĂctor. Universidad de la RepĂșblica; UruguayFil: Rossit, Daniel Alejandro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto de MatemĂĄtica BahĂa Blanca. Universidad Nacional del Sur. Departamento de MatemĂĄtica. Instituto de MatemĂĄtica BahĂa Blanca; Argentina. Universidad Nacional del Sur. Departamento de IngenierĂa; ArgentinaXXI Latin Ibero-American Conference on Operations Research -CLAIO 2022Buenos AiresArgentinaUniversidad de Buenos Aires. Facultad de Ciencias Exactas y Naturale
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
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