Phase-field modelling of failure in hybrid laminates

In this paper, the complex failure process of unidirectional hybrid laminates under uniaxial loading condition is reproduced and investigated by a one-dimensional phase-field model. The key ingredients of the approach, describing the mechanical response of a hybrid composite made of two different layers, are: (i) a phase-field method, based on a variational formulation of brittle fracture with regularised approximation of discontinuities for the two layers, (ii) cohesive law for the adhesive interface that connects the layers and (iii) robust and consolidated numerical strategy for the solution of the non-linear discretised problem. Explicit and well detailed simulations are shown for four peculiar failure mechanisms and the outcomes validated against experimental results available in literature. The model is able to discriminate among these different failure mechanisms according to the geometrical and mechanical properties of the hybrid composite. Both delamination of the adhesive interface is followed and crack patterns within the materials are fully determined. Finally, the proposed approach opens new perspective studies in higher dimension settings

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The Global Impact of the COVID-19 Pandemic on Individuals’ and Couples’ Sexuality

The COVID-19 pandemic and its related restrictions significantly impacted individuals' health, wellbeing, and security. Isolation, limitation of movement, social distancing, and forced cohabiting have had a strong influence on all areas of people's lives as well as on their sexuality. Investigating how the COVID-19 outbreak and its consequences impacted people's sexuality was the primary aim of this review. Particularly, we focused on: (1) the variables associated with the improvement or the deterioration of individuals' and couples' lives during the pandemic; (2) the use of sex as a coping strategy; (3) the impact of COVID-19 outbreak on LGBT people. Results have shown that the worsening of sexual life seems to be related to couples' conflict, emotions and psychological difficulties, being female, being single or away from the partner, being a health care worker, and having children. Moreover, a detrimental effect on sexuality was associated with stress, forced cohabitation, routine, anxiety and worry about the job and the pandemic, feeling partner distance, being unhappy with their partner, and lack of privacy. On the other hand, improvements in sexuality were associated with living happily with a partner, being happy and satisfied with a partner, feeling less stressed and more bored, having more free time, having fewer recreation opportunities, and having minor workload. During the pandemic, there was an increase in using sex toys, pornography consumption, masturbating, and trying sexual experimentations. Among LGBT people, an increase was found in the number of casual sexual partners potentially due to the perceived lower likelihood of transmission through sex. Moreover, the increase in sexual activity may have represented a coping strategy to quarantine-related distress

A definitional implementation of the LAX logical framework LLFP in CoQ, for supporting fast and loose reasoning

The Lax Logical Framework, LLFP, was introduced, by a team including the last two authors, to provide a conceptual framework for integrating different proof development tools, thus allowing for external evidence and for postponing, delegating, or factoring-out side conditions. In particular, LLFP allows for reducing the number of times a proof-irrelevant check is performed. In this paper we give a shallow, actually definitional, implementation of LLFP in Coq, i.e. we use Coq both as host framework and oracle for LLFP. This illuminates the principles underpinning the mechanism of Lock-types and also suggests how to possibly extend Coq with the features of LLFP. The derived proof editor is then put to use for developing case-studies on an emerging paradigm, both at logical and implementation level, which we call fast and loose reasoning following Danielsson et alii [6]. This paradigm trades off efficiency for correctness and amounts to postponing, or running in parallel, tedious or computationally demanding checks, until we are really sure that the intended goal can be achieved. Typical examples are branch-prediction in CPUs and optimistic concurrency control

The Impact of Contingency Management on Quality of Life Among Cocaine Abusers With and Without Alcohol Dependence

The use of quality of life measures (QOL) in substance abuse treatment research is important because it may lead to a broader understanding of patients’ health status and effects of interventions. Despite the high rates of comorbid cocaine and alcohol use disorders, little is known about the QOL of this population, and even less about the impact of an efficacious behavioral treatment, contingency management (CM), on QOL. In this study, data from three clinical trials were retrospectively analyzed to examine QOL in outpatient cocaine abusers with and without alcohol dependence (AD) and the impact of CM on QOL over time as a function of AD status. Patients were randomized to standard care (n = 115) or standard care plus CM (n = 278) for 12 weeks. QOL was assessed at baseline and Months 1, 3, 6, and 9. At treatment initiation, AD patients had lower QOL total scores and they scored lower on several subscale scores than those without AD. CM treatment was associated with improvement in QOL regardless of AD status. These data suggest that CM produces benefits that go beyond substance abuse outcomes, and they support the use of QOL indices to capture information related to treatment outcomes

Structure of the FeBTC Metal\u2013Organic Framework: A Model Based on the Local Environment Study

The local environment of iron in FeBTC, a metal organic framework commercially known as Basolite F300, is investigated combining XANES and EXAFS studies of the iron K-edge. The building block of the FeBTC can be described as an iron acetate moiety. Dehydration induces a change in the coordination of the first shell while preserving the network. We propose that the local structure around Fe atoms does not undergo a rearrangement, thus, leading to the formation of an open site. The analysis conveys that the FeBTC is a disordered network of locally ordered blocks

Early prediction of Autism Spectrum Disorders through interaction analysis in home videos and explainable artificial intelligence

There is considerable discussion about the advantages and disadvantages of early ASD diagnosis. However, the development of easily understandable and administrable tools for teachers or caregivers in order to identify potentially alarming behaviours (red flags) is usually considered valuable even by scholars who are concerned with very early diagnosis. This study proposes an AI pre-screening tool with the aim of creating an easily administrable tool for non-competent observers useful to identify potentially alarming signs in pre-verbal interactions. The use of these features is evaluated using an explainable artificial intelligence algorithm to assess which of the proposed new interaction characteristics were more effective in classifying individuals with ASD vs. controls. We used a rating scale with three core sections - sensorimotor, behavioural, and emotional - each further divided into four items. By seeing home videos of children doing everyday activities, two experienced observers rated each of these items from 1 (highly typical interaction) to 8 (extremely atypical interaction). Then, a machine learning model based on XGBoost was developed for identifying ASD children. The classification obtained was interpreted through the use of SHAP explanations, obtaining an area under the receiver operating curve of 0.938 and 0.914 for the two observers, respectively. These results demonstrated the significance of early detection of body-related sensorimotor features

LF+ in Coq for fast-and-loose reasoning

We develop the metatheory and the implementation, in Coq, of the novel logical framework LF+ and discuss several of its applications. LF+ generalises research work, carried out by the authors over more than a decade, on Logical Frameworks conservatively extending LF and featuring lock-type constructors L-P(N:sigma)[center dot]. Lock-types capture monadically the concept of inhabitability up-to. They were originally introduced for factoring-out, postponing, or delegating to external tools the verification of time-consuming judgments, which are morally proof-irrelevant, thus allowing for integrating different sources of epistemic evidence in a unique Logical Framework. Besides introducing LF+ and its "shallow" implementation in Coq, the main novelty of the paper is to show that lock-types are also a very flexible tool for expressing in Type Theory several diverse cognitive attitudes and mental strategies used in ordinary reasoning, which essentially amount to reasoning up-to, as in e.g. Typical Ambiguity provisos or co-inductive Coq proofs. In particular we address the encoding of the emerging paradigm of fast-and-loose reasoning, which trades off efficiency for correctness. This paradigm, implicitly used normally in naive Set Theory, is producing considerable impact also in computer architecture and distributed systems, when branch prediction and optimistic concurrency control are implemented