Characterisation of Fibre Glass Panels for Naval Use

This work examines the characteristic of fiber glass composite panels constructed by Cantieri Arturo Stabile in Trapani (Italy): composite materials are very used in the naval applications, where high stiffness and resistance are required with reduced weight. Experimental tests are executed following ASTM or UNI EN rules, in particular the shear test is executed using a rig constructed to the purpose, designed following the rule ASTM D 4255-83. Besides the tests were simulated by analytical methods, by means of Cadec software and numerically by FEM software as Altair Hyperworks and Ansys, to evidence the error range of the experimental test and to obtain the configuration that can give suitable results also for more complex designs. The successive phase of optimization is useful to obtain a reduction of the thickness, without compromising the resistance, for a consequent reduction of the production cost and energy saving of the boat during its use

CFD Study of an Innovative Catamaran with Asymmetrical Hulls

The purpose of this paper is the study of the shape of catamaran with asymmetrical hulls by both experimental and numerical viewpoint. The experimental study is based on the towing tank tests on a catamaran hulls shape obtained from previous works, showing that the wave resistance is very low produces a lower energy loss and a greater effectiveness. The hulls shape is optimized by the CFD application by force of commercial software, which shows that the reduction of wasted energy is very sensitive to make some changes; in particular three different width of the catamaran are tested and their performances are compared

PROGETTAZIONE E VERIFICA SPERIMENTALE DI UNA MICROTURBINA IDRAULICA PER L\u2019INDUSTRIA ALIMENTARE

In questo articolo sono descritte le attivit\ue0 di ricerca e sviluppo di una micro-turbina idraulica inserita all\u2019interno di un macchinario che opera un nuovo processo di abbattimento della carica batterica applicabile nell\u2019industria dell\u2019imbottigliamento delle bevande. Peculiarit\ue0 della turbina progettata \ue8 la geometria della palettatura della girante, dritta ed a sviluppo puramente assiale, che ne rende estremamente economica la realizzazione. Lo scambio di energia avviene grazie al moto vorticoso impresso al fluido (swirl) mediante opportuno posizionamento dei condotti di adduzione. Lo studio della turbina \ue8 stato condotto mediante classico approccio unidimensionale, mentre il dimensionamento \ue8 stato effettuato con l\u2019ausilio di simulazioni CFD. Ultimata la progettazione, la turbina \ue8 stata realizzata e si \ue8 avviata una campagna di prove sperimentali su un banco di flussaggio appositamente allestito che ha consentito di verificare il soddisfacimento delle specifiche progettuali

Impact of Mutation Density and Heterogeneity on Papillary Thyroid Cancer Clinical Features and Remission Probability

BACKGROUND: The need to integrate the classification of cancer with information on the genetic pattern has emerged in recent years for several tumors. METHODS: The genomic background of a large series of 208 papillary thyroid cancers (PTC) followed at a single center was analyzed by a custom MassARRAY genotyping platform, which allows the simultaneous detection of 19 common genetic alterations, including point mutations and fusions. RESULTS: Of the PTCs investigated, 71% were found to have pathognomonic genetic findings, with BRAFV600E and TERT promoter mutations being the most frequent monoallelic alterations (42% and 23.5%, respectively), followed by RET/PTC fusions. In 19.2% of cases, two or more point mutations were found, and the co-occurrence of a fusion with one or more point mutation(s) was also observed. Coexisting BRAFV600E and TERT promoter mutations were detected in a subgroup of aggressive PTCs (12%). A correlation between several aggressive features and mutation density was found, regardless of the type of association (i.e., only point mutations, or point mutations and fusions). Importantly, Kaplan-Meier curves demonstrated that mutation density significantly correlated with a higher risk of persistent disease. In most cases, the evaluation of the allelic frequencies normalized for the cancer cell content indicated the presence of the monoallelic mutation in virtually all tumor cells. A minority of cases was found to harbor low allelic frequencies, consistent with the presence of the mutations in a small subset of cancer cells, thus indicating tumor heterogeneity. Consistently, the presence of coexisting genetic alterations with different allelic frequencies in some tumors suggests that PTC can be formed by clones/subclones with different mutational profiles. CONCLUSIONS: A large mono-institutional series of PTCs was fully genotyped by means of a cost- and time-effective customized panel, revealing a strong impact of mutation density and genetic heterogeneity on the clinical features and on disease outcomes, indicating that an accurate risk stratification of thyroid cancer cannot rely on the analysis of a single genetic event. Finally, the heterogeneity found in some tumors warrants attention, since the occurrence of this phenomenon is likely to affect response to targeted therapies

Analysis of mechanical behaviour of wood species by speckle interferometry

The understanding of the mechanical behaviour of wood is a very important task in modern structural engineering. This is due to the increasing role played by wood structures in modern architecture as well as to its use in the restoration of ancient buildings. However, solid mechanics of wood is very difficult since it is a complex, polymer-based, cellular, inhomogeneous material. Moreover, at the cellular scale wood is not a continuum due to the presence of vascular vacuums and it can be regarded as an anisotropic material. Conversely, at a macroscopic scale when the analysis is carried out on a structural member which is large in comparison to the size of cell, wood is usually considered as a continuous homogeneous orthotropic material and its mechanical behaviour is usually approached in cylindrical or rectangular coordinates. The above considerations emphasize the importance of experimental techniques able to investigate the behaviour of wood either at fibre or at macroscopic scale. Strain measurement at the fibre level has not yet been accomplished due to the loading effect on the measured quantity. Aim of the paper is to apply Electronic Speckle-Pattern Interferometry handled by phase-stepping technique to the experimental study of wood mechanical behaviour. The selected wood species are Red Spruce, Pitch Pine, Swedish Pine, Larch, belonging to the conifers, usually classified as softwoods, and Cherry-wood, Baky, Teak, Iroko, Doussi\ue8, Bahia belonging to the latifoliae, usually classified as hardwoods. In the paper the mechanical behaviour due to bending is investigated by adopting a four-point bending test. The obtained results are compared with those for an isotropic material (Plexiglas) in order to show the differences. The results confirm the complexity of the mechanics of wood and suggest further investigations in order to gain a deeper insight in of developing a correct approach from a structural point of view

Study of the performances of a fluidynamic actuator

Aim of this paper is presented a new methodology to study how different geometric parameters affect the performance of a hydraulic actuator. Preliminarily, the real working conditions of a hydraulic machine have been simulated by means of a CFD module. After, to test the reliability of the simulations, the obtained numerical results have been compared with the experimental data of a real prototype. This comparison demonstrates a good level of agreement between numerical and experimental results. Different simulations have been setup by modifying the actuator geometry and evaluating the efficiency of every analysed configuration. The results of this study give useful guidelines for the choice of the best geometry depending on the working conditions of the actuator