137 research outputs found

    Statistical significance of notch fatigue prognoses based on the strain-energy-density method: Application to conventionally and additively manufactured materials

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    The inverse search determination of the strain-energy–density (SED) control radius R1 devised in Benedetti et al. Int J Fatigue 2019;126:306–318 and based on the knowledge of the notch fatigue factor estimated using an optimal V-notch specimen geometry is here reformulated to take into account the statistical properties of the input fatigue properties. It was found that R1 exhibits a non-symmetric probability density function that is well represented by a skew-normal distribution. The uncertainty in R1 can be attributed to the uncertainty in the inverse search procedure and to the material variability in notch sensitivity. By applying the devised procedure to real experimental data, it was found that the former contribution is preponderant in the assessment of very sharp notches, while the latter dictates the fatigue strength of blunt notches, especially in the case of intrinsically flawed materials, such as those additively manufactured

    Perspectives of stack and environmental monitoring in the surroundings of a waste-to-energy plant

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    Waste-to-Energy (WtE) processes respond both to the emerging need for reducing the flow of waste into the environment and, at the same time, to the increasing demand for energy. Despite, these evident advantages, WtE plants still present some critical issues regarding the emissions of heavy metals into the atmosphere, which are regulated by the environmental legislations but, concerning the European Union, are regarded as groups of metals with no consideration of the different carcinogenic potential of each metal. In addition, there are uncertainties on the estimation of the balance of carbon dioxide, which depends on several factors like transportation, type of incoming waste, processes in use and secondary emissions. Despite great improvements in air pollution control from this sector, persistent organic pollutants are still emitted by WtE plants. Therefore, the implementation of adequate environmental monitoring (EM) plans is essential to monitor the impact of WtE plants in their surroundings, especially in the presence of the population, fields and pastures. In view of these considerations, this paper aims to provide guidance on basic and novel approaches that are necessary for a comprehensive monitoring of the impacts of a new WtE plant in terms of air quality and public health. A case study regarding the EM plan proposed for a new WtE plant will also be reported as an example

    SARS-CoV-2 structural coverage map reveals viral protein assembly, mimicry, and hijacking mechanisms

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    We modeled 3D structures of all SARS-CoV-2 proteins, generating 2,060 models that span 69% of the viral proteome and provide details not available elsewhere. We found that ˜6% of the proteome mimicked human proteins, while ˜7% was implicated in hijacking mechanisms that reverse post-translational modifications, block host translation, and disable host defenses; a further ˜29% self-assembled into heteromeric states that provided insight into how the viral replication and translation complex forms. To make these 3D models more accessible, we devised a structural coverage map, a novel visualization method to show what is-and is not-known about the 3D structure of the viral proteome. We integrated the coverage map into an accompanying online resource (https://aquaria.ws/covid) that can be used to find and explore models corresponding to the 79 structural states identified in this work. The resulting Aquaria-COVID resource helps scientists use emerging structural data to understand the mechanisms underlying coronavirus infection and draws attention to the 31% of the viral proteome that remains structurally unknown or dark

    Efeitos dos parâmetros operacionais do tratamento por eletrofloculação de aguas residuais da suinocultura.

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    A água residuária da saída do biodigestor apresenta elevado potencial poluidor podendo ocasionar impactos ambientais indesejáveis, quando aplicado em excesso no solo. Neste contexto, a eletrofloculação (EF) apresenta-se como uma técnica promissora, devido a sua facilidade de operação e elevada eficiência. O objetivo desse estudo foi avaliar o desempenho da EF no tratamento de água residuária da suinocultura, submetida a pré-digestão anaeróbia, em sistema batelada. O efluente utilizado no tratamento foi coletado na saída de um biodigestor na unidade da Embrapa Suínos e Aves. O reator de EF em batelada possui capacidade de tratar 1,7 litros de efluente, com dois pares de eletrodos de alumínio, com dimensões de 130 mm de altura e 70 mm de largura, ligados a uma fonte de corrente contínua, sendo o sistema mantido sob agitação constante, o pH do efluente foi ajustado para 6,0 e o tempo de tratamento foi de 60 minutos. Um planejamento fatorial 22 foi aplicado para avaliar as variáveis: distância entre os eletrodos e a voltagem. Resultados de eficiência de remoção (%) para a condição 3cm 6V foram de 99%, 71%, 3% e 83% para turbidez, COT, Ntotal e DQO, respectivamente. O sistema de EF em batelada reproduziu resultados satisfatórios, assim tornando-se uma alternativa promissora a ser aplicada para tratamento de resíduos líquidos provenientes da suinocultura

    Hamiltonian Dynamics and the Phase Transition of the XY Model

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    A Hamiltonian dynamics is defined for the XY model by adding a kinetic energy term. Thermodynamical properties (total energy, magnetization, vorticity) derived from microcanonical simulations of this model are found to be in agreement with canonical Monte-Carlo results in the explored temperature region. The behavior of the magnetization and the energy as functions of the temperature are thoroughly investigated, taking into account finite size effects. By representing the spin field as a superposition of random phased waves, we derive a nonlinear dispersion relation whose solutions allow the computation of thermodynamical quantities, which agree quantitatively with those obtained in numerical experiments, up to temperatures close to the transition. At low temperatures the propagation of phonons is the dominant phenomenon, while above the phase transition the system splits into ordered domains separated by interfaces populated by topological defects. In the high temperature phase, spins rotate, and an analogy with an Ising-like system can be established, leading to a theoretical prediction of the critical temperature TKT0.855T_{KT}\approx 0.855.Comment: 10 figures, Revte

    Why place matters in residential care: the mediating role of place attachment in the relation between adolescents’ rights and psychological well-being

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    Little evidence exists on the relationship between rights’ perceptions and well-being outcomes during the adolescence, and particularly in care, as well as on the mediating role of place attachment. Young people in residential care are psychologically and socially vulnerable, showing greater difficulties than their peers do in the family. Youth’s rights fulfilment in residential care may positively affect their psychological functioning together with positive attachments to this place. A sample of 365 adolescents in residential care settings (M = 14.71, SD = 1.81) completed a set of self-reported measures, specifically, the Rights perceptions scale, the Place attachment scale and Scales of psychological well-being. Results revealed significant mediating effects of place attachment (Global scale and subscales of Friends Bonding and Place Dependence) on the relationship between Participation and Protection rights in residential care and Psychological well-being (Positive Relations with others, Personal Growth and Self-Acceptance). The positive role of rights fulfilment in residential care, specifically participation opportunities, as well as the role of youth’s attachment to the care setting are discussed based on previous evidence and theoretical assumptions. A set of practical implications is described.info:eu-repo/semantics/acceptedVersio
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