Cohesive crack approach to debonding analysis

Debonding of coatings from substrate due to coating compression occurs in many engineering applications. A simplified analytical approach for the estimation of the ultimate coating compression leading to debonding is developed in this paper, assuming an assigned out-of-plane defect of the coating. The formulation is based on the solution of a beam on a Pasternak (two parameters) elastic foundation, and on the assumption of a Mode I cohesive failure of the coating-substrate interface. The resulting formulas are simple and require the knowledge of a limited number of parameters

Prevalence and Correlates of Sexually Transmitted Infections in Transgender People: An Italian Multicentric Cross-Sectional Study

The burden of sexually transmitted infections (STIs) in the transgender population remains an underestimated issue. The aims of the present study were to evaluate the prevalence of either self-reported and serological STIs and to describe socio-demographic and clinical characteristics of transgender individuals with STIs. A consecutive series of 705 transgender individuals (assigned-male at birth, AMAB n = 377; assigned-female at birth, AFAB n = 328) referring to six Italian gender clinics were included. Sociodemographic and clinical information was collected during the first visit. In a subsample of 126 individuals prevalence of STIs (human immunodeficiency virus, HIV; hepatitis C, HCV; hepatitis B, HBV; syphilis) were evaluated through serology tests. The self-reported prevalence of HIV, HBV, HCV and syphilis infection in the total sample were 3.4%, 1.6%, 2.6% and 2.0%, respectively. In the subsample who underwent serological tests, higher rates of serological prevalence were found (9.5%, 4.0%, 5.6% and 7.9% for HIV, HBV, HCV and syphilis, respectively). When comparing transgender people with or without selfreported STIs, unemployment, previous incarceration, justice problems and sex work resulted more frequent in the first group (p< 0.03 for all). Regarding health status, we observed higher rates of lifetime substance abuse and psychiatric morbidities in trans people with at least one reported STI (p < 0.05). The prevalence of STIs exceeded that reported in general population and STIs correlates underline the importance of stigma and discrimination as determinants of transgender health

Strength assessment of adhesively bonded tile claddings

A simplified analytical approach for the assessment of bonding strength in tiled flooring is formulated and discussed. The approach is conceived for application to a specific type of failure mechanism, usually activated by differential elongation/shortening between tiles and substrate, of the type induced by thermal gradients or fresh concrete maturation. It is discussed how the failure mechanism, promoted by eccentric tile compression, can be studied as a Mode I cohesive crack propagation through the adhesive layer and a closed form estimate of the ultimate tile compression is provided. Based on closed-form solutions for the problem of stress transfer between substrate and tile through shear of the adhesive, simple formulas for the estimation of the tile compression are also derived

A simplified numerical approach for studying the pile-landslide interaction in hard soils

Vertical piles can be profitably employed as deep retaining structures to prevent landslides, providing a convenient restraint to soil movements. The design procedures commonly employed in engineering practice to evaluate the mechanical response of piles to lateral loads are usually based on P-y curves, giving the value of the local interaction force as a function of the local pile deflection (i.e. the interaction between each slice of the pile and the surrounding soil). In the present paper a simplified procedure, capable of computing the global resultant interaction force arising between the pile and the soil moving mass as a function of the soil displacement, is presented. Non linearities of both the structure and the soil can be taken into consideration, in particular with reference to the case of piles drilled in hard soils, usually characterized, these latter, by a softening mechanical behaviour. The influence of both the shape of the soil displacement profile and of additional constraints (like deep pretensioned ground anchors) is investigated as well

Soil-pipeline interaction along active fault systems

The problem of soil-pipe interaction along active faults is numerically taken into consideration by following a displacement-based approach. The interaction is analysed by means of lumped coupled elastoplastic springs, whose failure locus is linearized piece-wise, and the equations governing their behaviour are set in a form such that a linear complementarity problem can be formulated. The numerical formulation is conceived for taking large displacements into account. The ground motion is controlled; the solution is presented in terms of pipe displacements and internal pipe actions, and its dependency on geometrical parameters is discussed. The problem of the axial instability of the pipeline is also studied