0000000001279450
AUTHOR
M Salerno
Active macro-zones algorithm via multidomain SBEM for strain-hardening elastoplastic analysis
In this paper a strategy to perform strain-hardening elastoplastic analysis by using the Symmetric Boundary Element Method (SBEM) for multi-domain type problems is shown. The procedure has been developed inside Karnak.sGbem code by introducing an additional module.
MACRO-ZONES SGBEM APPROACH FOR STATIC SHAKEDOWN ANALYSIS AS CONVEX OPTIMIZATION
A new strategy utilizing the Multidomain SGBEM for rapidly performing shakedown analysis as a convex optimization problem has been shown in this paper. The present multidomain approach, called displacement method, makes it possible to consider step-wise physically and geometrically nonhomogeneous materials and to obtain a self-equilibrium stress equation regarding all the bem-elements of the structure. Since this equation includes influence coefficients, which characterize the input of the quadratic constraints, it provides a nonlinear optimization problem solved as a convex optimization problem. Furthermore, the strategy makes it possible to introduce a domain discretization exclusively of…
Frctionless contact: step by step analysis and mathematical programming technique
The object of the paper concerns a consistent formulation of the classical Signorini's theory regarding the frictionless unilateral contact problem between two elastic bodies in the hypothesis of small displacements and strains. A variational approach employed in conjunction with the Symmetric Boundary Element Method (SBEM) leads to an algebraic formulation based on generalized quantities [1]. The contact problem is decomposed into two sub-problems: one is purely elastic, the other pertains to the unilateral contact conditions alone [2,3]. Following this methodology, the contact problem, by symmetric BEM, is characterized by symmetry and sign definiteness of the coefficient matrix, thus adm…
Severity of Asymptomatic Carotid Stenosis and Risk of Ipsilateral Hemispheric Ischaemic Events: Results from the ACSRS Study
Objectives. This study determines the risk of ipsilateral ischaemic neurological events in relation to the degree of asymptomatic carotid stenosis and other risk factors. Methods. Patients (n = 1115) with asymptomatic internal carotid artery (ICA) stenosis greater than 50% in relation to the bulb diameter were followed up for a period of 6-84 (mean 37.1) months. Stenosis was graded using duplex, and clinical and biochemical risk factors were recorded. Results. The relationship between ICA stenosis and event rate is linear when stenosis is expressed by the ECST method, but S-shaped if expressed by the NASCET method. In addition to the ECST grade of stenosis (RR 1.6; 95% CI 1.21-2.15), histor…
SHAKEDOWN ANALYSIS BY BEM
In the ambit of the symmetric Galerkin boundary element formulation the statical shakedown load multiplier and the limit analysis are reformulated making use of macrozone modelling. The subdivision of the domain into macroelements makes it possible to deal with piecewise homogeneous materials of the body. For each macroelement a discretization of the boundary and a subdivision of the domain into portions called cells are performed in order to introduce the unknowns (i.e. traction and displacement discontinuities) on the boundary and material plastic laws appropriately interpolated. The weighed regularity imposed between adjacent macroelements produces algebraic operators which are symmetric…
Il metodo degli spostamenti nella formulazione simmetrica degli elementi di contorno
Il metodo degli elementi di contorno nella sua versione simmetrica (SGBEM) sta assumendo un ruolo sempre più incisivo per la soluzione di vari problemi di ingegneria. Recentemente ci si è occupati di impiegare tale metodo a corpi bidimensionali piani costituiti da materiale aventi differenti proprietà fisiche attraverso una suddivisione in sottodomini denominati macroelementi.
THE PSYCHOTERAPEUTIC INTERVENTIONS AND STRATEGIES FOR CHILDREN AND ADOLESCENTS WITH BEHAVIOURAL DISORDERS: THE INCREDIBLE YEARS TREATMENT PROGRAM
The psychotherapeutic interventions disposable and considered the key role in behavioral therapy are the Incredible Years, the evidence-based parenting support
Frictionless contact formulation by mathematical programming technique
The object of the paper concerns a consistent formulation of the classical Signorini's theory regarding the frictionless unilateral contact problem between two elastic bodies in the hypothesis of small displacements and strains. A variational approach, employed within the symmetric Boundary Element Method, leads to an algebraic formulation based on nodal quantities. The contact problem is decomposed into two sub-problems: one is purely elastic, and the other pertains to the unilateral contact condition alone. Following this methodology, the contact problem, faced with symmetric BEM, is characterized by symmetry and sign definiteness of the coefficient matrix, thus admitting a unique solutio…
Pediatric selective mutism and sleep disorders: A pilot restrospective case control-study
Introduction: Selective mutism (SM) is characterized by the persistent inability to speak in some specific contexts (i.e. school, home, social contexts) or within interaction with peer group and/or adults when a normal verbal linguistic competence may be expected, according to DSM5 criteria. The main sleep disorders in children with neurodevelopmental disorders are represented by difficulty in falling asleep at night (51%) and nocturnal awakenings (67%).The main goal of the present study is verify the putative relationship between sleep disorders and selective mutism in children.Materials and methods: 30 children were diagnosed with SM (13 males and 17 females) with mean age 9.47 (SD +/- 12…
The size of juxtaluminal hypoechoic area in ultrasound images of asymptomatic carotid plaques predicts the occurrence of stroke
Abstract OBJECTIVE: To test the hypothesis that the size of a juxtaluminal black (hypoechoic) area (JBA) in ultrasound images of asymptomatic carotid artery plaques predicts future ipsilateral ischemic stroke. METHODS: A JBA was defined as an area of pixels with a grayscale value 10 mm(2) (P 8 mm(2)) was still significant after adjusting for other plaque features known to be associated with increased risk, including stenosis, grayscale median, presence of discrete white areas without acoustic shadowing indicating neovascularization, plaque area, and history of contralateral TIA or stroke. Plaque area and grayscale median were not significant. Using the significant variables (stenosis, discr…
A BRIEF ANATOMO-SURGICAL DISSECTION GUIDE TO HUMAN NECK: RESULTS OF THE COLLABORATION BETWEEN THE UNIVERSITY OF PALERMO AND THE UNIVERSITY OF MALTA
The aim of this article is to show methods for dissection of the neck. In the summer of 2017 a group of students of the University of Palermo that have already passed the exam of Human Anatomy took a 4 weeks dissection course at the University of Malta. The students were provided with a dissection kit, video recording equipment and cameras for taking pictures. They dissected the skin, the subcutaneous tissue, the muscular bundles, the muscles, the vascular and nervous bundles, the nerves, the larynx, the trachea and the esophagus. This paper presents the results of the dissection course and a small and simple guide to young students and medical doctors who want to learn the bases of neck di…