733 research outputs found

    5% lidocaine medicated plaster double effect in a case of orofacial localized neuropathic pain

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    Roberto Casale,1,2 Yuriy Romanenko,2,3 Massimo Allegri4–6 1Department of Clinical Neurophysiology and Pain Rehabilitation Unit, Foundation "Salvatore Maugeri", Research and Care Institute, IRCCS, Pavia, Italy; 2EFIC Montescano Pain School, Montescano, Italy; 3Department of Neurology, Lugansk City Hospital 4, Lugansk, Ukraine; 4Department of Clinical, Surgical, Diagnostic and Pediatric Sciences University of Pavia, Pavia, Italy; 5Pain Therapy Service Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; 6SIMPAR group, Pavia, Italy Abstract: Localized neuropathic pain (LNP) is a type of neuropathic pain that is characterized by “consistent and limited area(s) of maximum pain associated with negative or positive sensory signs and/or spontaneous symptoms characteristic of neuropathic pain”. This definition encompasses a huge number of neuropathic orofacial pain syndromes. We present a case report of a patient who was affected with sleep apnea syndrome treated with nocturnal oxygen mask delivery, in whom orofacial LNP hampered the wearing of a mask due to unbearable burning and throbbing pain. The application of 5% lidocaine medicated plaster during the night led to an impressive reduction of both the pain level and the size of the painful area due to the plaster's pharmacological mechanisms, which were associated with a secondary benefit due to its mechanical protective action. This case report shows how these two factors could be of clinical value and have to be considered more systematically in the treatment of LNP in reducing pain and the size of the painful area. Keywords: trigeminal pain, localized neuropathic pain, topical treatment, 5% lidocaine medicated plaste

    Political Parties and Political Foundations in Italy. Their Changing Landscape of Structure and Financing

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    This book, published with research funds from the University of Rome La Sapienza, aims at disseminating knowledge about the Italian system of political parties and political foundations among non-Italian scholars, in the light of the recent legislative reforms in this field. Due to their nature as free associations of citizens under art. 49 Cost., political parties are supposed to enjoy a full autonomy in determining their own purposes, internal organisation and financial management. However, the recent regulation on the funding of political parties contains provisions aimed at influencing the contents of party statutes, imposing upon them several organisational obligations. Moreover, some draft laws concerning the internalfunding have been proposed, with the idea of making intra-party democracy not only a prerequisite for obtaining funds, but also for competing in elections. However, many argue that a law should be the least invasive possible, and parties should instead proceed to self-reformation. The stronger the erosion process of party organisations and of political cultures is, the more strongly affirmed will be the personalised models of political organisation, in which even the funding of the organisation’s own public viability is managed autonomously. This is why ever more frequently some political leaders make use of think tanks for fund-raising, by virtue of the broad degree of autonomy that they enjoy

    A Simplified Layered Beam Approach for Predicting Ply Drop Delamination in Thick Composite Laminates

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    The prediction of delamination onset is a challenging task in the design of thick tapered composite laminates, where multiple ply terminations (“drop-offs”) are present. This paper addresses the development of a global-local finite element-based design approach for tapered laminates, whereby layered Timoshenko beam models are employed to predict delamination initiation from individual drop-offs. This modelling strategy provides a fast and conservative method for evaluating the strength of tapered composite laminates. Parametric test cases are presented in order to validate the methodology and understand its limitations. Finally, the application of the tool to a relatively thick tapered composite test specimen comprising multiple ply-drops is demonstrated

    A novel model of delamination bridging via Z-pins in composite laminates

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    AbstractA new micro-mechanical model is proposed for describing the bridging actions exerted by through-thickness reinforcement on delaminations in prepreg based composite materials, subjected to a mixed-mode (I–II) loading regime. The model applies to micro-fasteners in the form of brittle fibrous rods (Z-pins) inserted in the through-thickness direction of composite laminates. These are described as Euler–Bernoulli beams inserted in an elastic foundation that represents the embedding composite laminate. Equilibrium equations that relate the delamination opening/sliding displacements to the bridging forces exerted by the Z-pins on the interlaminar crack edges are derived. The Z-pin failure meso-mechanics is explained in terms of the laminate architecture and the delamination mode. The apparent fracture toughness of Z-pinned laminates is obtained from as energy dissipated by the pull out of the through-thickness reinforcement, normalised with respect to a reference area. The model is validated by means of experimental data obtained for single carbon/BMI Z-pins inserted in a quasi-isotropic laminate

    Cohesive element formulation for z-pin delamination bridging in fibre reinforced laminates

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    Z-pins are an effective method of reinforcing laminated composite materials for resisting the propagation of delamination. In this paper, a novel numerical method combines the classical cohesive finite element (FE) method with a semi-analytical z-pin crack bridging model. Special purpose cohesive elements, in which the generalized traction-displacement characteristics are provided by the semi-analytical model z-pin bridging map, are implemented in macro-scale FE models. This cohesive element offers the flexibility to employ two cohesive laws concurrently for prediction of delamination propagation, for both the pinned and unpinned behaviour. Its efficacy is evaluated by the simulation of double cantilever beam (DCB), mixed-mode bend (MMB), and pure mode II End-Loaded Split (ELS) fracture tests at 2% z-pin areal density. The numerical results in terms of load-deflection predictions agree well with experiments. The different simulations were all performed using a single set of input parameters derived from single z-pin tests with no fitting factors

    Novel parametric reduced order model for aeroengine blade dynamics

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    © 2015 Elsevier Ltd. All rights reserved.The work introduces a novel reduced order model (ROM) technique to describe the dynamic behavior of turbofan aeroengine blades. We introduce an equivalent 3D frame model to describe the coupled flexural/torsional mode shapes, with their relevant natural frequencies and associated modal masses. The frame configurations are identified through a structural identification approach based on a simulated annealing algorithm with stochastic tunneling. The cost functions are constituted by linear combinations of relative errors associated to the resonance frequencies, the individual modal assurance criteria (MAC), and on either overall static or modal masses. When static masses are considered the optimized 3D frame can represent the blade dynamic behavior with an 8% error on the MAC, a 1% error on the associated modal frequencies and a 1% error on the overall static mass. When using modal masses in the cost function the performance of the ROM is similar, but the overall error increases to 7%. The approach proposed in this paper is considerably more accurate than state-of-the-art blade ROMs based on traditional Timoshenko beams, and provides excellent accuracy at reduced computational time when compared against high fidelity FE models. A sensitivity analysis shows that the proposed model can adequately predict the global trends of the variations of the natural frequencies when lumped masses are used for mistuning analysis. The proposed ROM also follows extremely closely the sensitivity of the high fidelity finite element models when the material parameters are used in the sensitivity
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