Search

The sedimentation of micro and nanosized plastics is of considerable environmental relevance and the need to assess its sublethal effects to biota increasingly recognized. In their majority, as bottom, non-selective grazers, independent-feeding young life stages of amphibians, an already severely endangered worldwide group, may be particularly vulnerable to sedimented plastics. Alongside, they may be good model organisms for the assessment of the effects of micro(nano)plastics (MNPs) through ingestion. However, to our knowledge, few studies have assessed amphibians' exposure to MNPs through contaminated food or its effects in feeding behaviour assays. The available studies reveal a lack of consistent methodology: organisms, food type, media of exposure, or exposure conditions (temperature and light) in the assessment of effects. This perspective article, will address major differences found in the available studies, identifying type, size and concentrations of the polymers tested, species, and observed effects, aiming to highlight the importance of feeding exposure assays when attempting to evaluate the effect of MNPs in amphibians. [ABSTRACT FROM AUTHOR]

The sedimentation of micro and nanosized plastics is of considerable environmental relevance and the need to assess its sublethal effects to biota increasingly recognized. In their majority, as bottom, non-selective grazers, independent-feeding young life stages of amphibians, an already severely endangered worldwide group, may be particularly vulnerable to sedimented plastics. Alongside, they may be good model organisms for the assessment of the effects of micro(nano)plastics (MNPs) through ingestion. However, to our knowledge, few studies have assessed amphibians' exposure to MNPs through contaminated food or its effects in feeding behaviour assays. The available studies reveal a lack of consistent methodology: organisms, food type, media of exposure, or exposure conditions (temperature and light) in the assessment of effects. This perspective article, will address major differences found in the available studies, identifying type, size and concentrations of the polymers tested, species, and observed effects, aiming to highlight the importance of feeding exposure assays when attempting to evaluate the effect of MNPs in amphibians. [ABSTRACT FROM AUTHOR]

Abstract: A new inverse technique to characterise the nonlinear mechanical properties of viscoelastic core layers in sandwich panels has been developed based on simple vibration tests. The present methodology allows one to preserve the frequency and temperature dependences of the storage and loss moduli of viscoelastic materials for a wide range of frequencies and to perform a structural analysis using high damping tests. The computational effort has been substantially reduced by using an optimisation based on the planning of the experiments and the response surface technique in order to minimise the error functional. This new inverse technique has been tested and applied to characterise the viscoelastic properties of a 3M damping polymer (ISD-112) used as a core material in sandwich panels. The identified material properties have been verified successfully by comparing structural dynamic parameters obtained from the numerical analysis with experiments. [Copyright &y& Elsevier]