On the flexural vibration of cylinders under axial loads:Numerical and experimental study

The flexural vibration of a homogeneous isotropic linearly elastic cylinder of any aspect ratio is analysed in this paper. Natural frequencies of a cylinder under uniformly distributed axial loads acting on its bases are calculated numerically by the Ritz method with terms of power series in the coordinate directions as approximating functions. The effect of axial loads on the flexural vibration cannot be described by applying infinitesimal strain theory, therefore, geometrically nonlinear strain–displacement relations with second-order terms are considered here. The natural frequencies of free–free, clamped–clamped, and sliding–sliding cylinders subjected to axial loads are calculated using the proposed three-dimensional Ritz approach and are compared with those obtained with the finite element method and the Bernoulli–Euler theory. Different experiments with cylinders axially compressed by a hydraulic press are carried out and the experimental results for the lowest flexural frequency are compared with the numerical results. An approach based on the Ritz formulation is proposed for the flexural vibration of a cylinder between the platens of the press with constraints varying with the intensity of the compression. The results show that for low compressions the cylinder behaves similarly to a sliding–sliding cylinder, whereas for high compressions the cylinder vibrates as a clamped–clamped one

A public early intervention approach to first-episode psychosis: Treated incidence over 7 years in the Emilia-Romagna region

AimTo estimate the treated incidence of individuals with first-episode psychosis (FEP) who contacted the Emilia-Romagna public mental healthcare system (Italy); to examine the variability of incidence and user characteristics across centres and years. MethodsWe computed the raw treated incidence in 2013-2019, based on FEP users aged 18-35, seen within or outside the regional program for FEP. We modelled FEP incidence across 10 catchment areas and 7 years using Bayesian Poisson and Negative Binomial Generalized Linear Models of varying complexity. We explored associations between user characteristics, study centre and year comparing variables and socioclinical clusters of subjects. ResultsThousand three hundred and eighteen individuals were treated for FEP (raw incidence: 25.3 / 100.000 inhabitant year, IQR: 15.3). A Negative Binomial location-scale model with area, population density and year as predictors found that incidence and its variability changed across centres (Bologna: 36.55; 95% CrI: 30.39-43.86; Imola: 3.07; 95% CrI: 1.61-4.99) but did not follow linear temporal trends or density. Centers were associated with different user age, gender, migrant status, occupation, living conditions and cluster distribution. Year was associated negatively with HoNOS score (R = -0.09, p < .001), duration of untreated psychosis (R = -0.12, p < .001) and referral type. ConclusionsThe Emilia-Romagna region presents a relatively high but variable incidence of FEP across areas, but not in time. More granular information on social, ethnic and cultural factors may increase the level of explanation and prediction of FEP incidence and characteristics, shedding light on social and healthcare factors influencing FEP

The characteristics and activities of child and adolescent mental health services in Italy: a regional survey

<p>Abstract</p> <p>Background</p> <p>To date, no studies have assessed in detail the characteristics, organisation, and functioning of Child and Adolescent Mental Health Services (CAMHS). This information gap represents a major limitation for researchers and clinicians because most mental disorders have their onset in childhood or adolescence, and effective interventions can therefore represent a major factor in avoiding chronicity. Interventions and mental health care are delivered by and through services, and not by individual, private clinicians, and drawbacks or limitations of services generally translate in inappropriateness and ineffectiveness of treatments and interventions: therefore information about services is essential to improve the quality of care and ultimately the course and outcome of mental disorders in childhood and adolescence.</p> <p>The present paper reports the results of the first study aimed at providing detailed, updated and comprehensive data on CAMHS of a densely populated Italian region (over 4 million inhabitants) with a target population of 633,725 subjects aged 0-17 years.</p> <p>Methods</p> <p>Unit Chiefs of all the CAMHS filled in a structured 'Facility Form', with activity data referring to 2008 (data for inpatient facilities referred to 2009), which were then analysed in detail.</p> <p>Results</p> <p>Eleven CAMHS were operative, including 110 outpatient units, with a ratio of approximately 20 child psychiatrists and 23 psychologists per 100,000 inhabitants aged 0-17 years. All outpatient units were well equipped and organized and all granted free service access. In 2008, approximately 6% of the target population was in contact with outpatient CAMHS, showing substantial homogeneity across the eleven areas thereby. Most patients in contact in 2008 received a language disorder- or learning disability diagnosis (41%). First-ever contacts accounted for 30% of annual visits across all units. Hospital bed availability was 5 per 100,000 inhabitants aged 0-17 years.</p> <p>Conclusion</p> <p>The percentage of young people in contact with CAMHS for mental disorders is in line with those observed in previous epidemiological studies. The overall number of child psychiatrists per 100,000 inhabitants is one of the highest in Europe and it is comparable with the most well equipped areas in the US. This comparison should be interpreted with caution, however, because in Italy, child psychiatrists also treat neurological disorders. Critical areas requiring improvement are: the uneven utilisation of standardised assessment procedures and the limited availability of dedicated emergency services during non-office hours (e.g., nights and holidays).</p

Static analysis of Timoshenko beam resting on elastic half-plane based on the coupling of locking-free finite elements and boundary integral

Making use of a mixed variational formulation including the Green function of the soil and assuming as independent fields both the structure displacements and the contact pressure, a finite element model is derived for the static analysis of a foundation beam resting on elastic half-plane. Timoshenko beam model is adopted to describe structural foundations with low slenderness and to impose displacement compatibility between beam and half-plane without requiring the continuity of the first order derivative of the surface displacements enforced by Euler-Bernoulli beam. Numerical results are obtained by using locking-free Hermite polynomials for the Timoshenko beam and constant reaction over the soil. Foundation beams loaded by many load configurations illustrate accuracy and convergence properties of the proposed formulation. Moreover, the different behaviour of the Euler-Bernoulli and Timoshenko beam models is thoroughly discussed. Rectangular pipe loaded by a force in the upper beam exemplifies the straightforward coupling of the foundation finite element with a structure described by usual finite elements

Nonlocal behavior of a mixed F.E. model for soil-foundations interaction problems

Starting from a mixed variational formulation including the Green function of the soil, a F.E. model is derived for the interaction of a foundation beam with the underlying soil. Numerical results are obtainedn by adopting Hermite cubics for the beam deflection and constant soil reaction over each element. It is shown that the soil stiffness matrix exhibits a strong diagonal dominance and explicit techniques for the construction of an approximate sparse matrix are discussed

Torri pendenti in muratura di mattoni: il campanile di S. Benedetto in Ferrara.

In questo lavoro viene generalizzato il problema affrontato da Jacques Heyman dell’inclinazione critica delle torri pendenti in muratura, assumendo un asse generico di rota-zione. Vengono considerate superfici di rottura piane e curve utilizzando rispettivamente una formulazione di tipo analitico ed una di tipo numerico. In entrambi i casi, vengono esclusi modi di collasso locali. Viene analizzato il caso del campanile di S. Benedetto in Ferrara che presenta uno strapiombo di m 2.50, determinandone il coefficiente di sicurezza rispetto alla rotazione

Minimi retributivi e retribuzioni al minimo. Riflessioni teoriche e riscontri empirici

The authors introduce the main topics dealt with in the articles of the issue, highlighting their different perspectives of analysis and interconnections. They also emphasise the several methodological approaches adopted, explaining how theoretical reflections are coupled with empirical investigations and assessments. In the lack of an Italian minimum wage legilslation, the role of collective agreements in the setting and protection of minimum pay levels is examined from multiple angles, which include an analysis of instruments to fight against collective bargaining dumping, also in the context of posted workers and outsourcing. © Società editrice il Mulin

Debonding of FRP and thin films from an elastic half-plane using a coupled FE-BIE model

A Finite Element-Boundary Integral Equation (FE-BIE) coupling method is proposed to investigate a flexible bar weakly attached to an elastic orthotropic half-plane. Firstly, the analysis focused on the case of a bar subjected to horizontal forces and thermal loads considering interfacial displacements linearly proportional to the tangential traction. Secondly, the debonding behaviour of a composite reinforcement glued to a substrate has been modelled. Using an incremental nonlinear analysis, a bilinear elastic-softening interfacial traction-slip law has been implemented simulating the delamination of pure Mode II. Finally, the influence of the anchorage length on the ultimate bearing capacity of the adhesive joint has been investigated

Interfacial shear stress analysis of bar and thin film bonded to 2D elastic substrate using a coupled FE-BIE method

In the present work, a Finite Element-Boundary Integral Equation (FE-BIE) coupling method is proposed to investigate the problem of axially loaded thin structures bonded to a homogeneous elastic half-plane. Making use of a mixed variational formulation including the Green function of the substrate, the axial displacement of the bar is interpolated by using Lagrange polynomials of first or second order, whereas the interfacial shear stress is approximated by piecewise constant functions. Bars subject to different load conditions are investigated, including the case of a bar partially detached from the substrate. The strength of interfacial stress singularities are investigated in detail