Sunscreens’ uv filters risk for coastal marine environment biodiversity: A review

Considering the rapid growth of tourism in recent years and the acknowledgement that exposure to solar UV radiation may cause skin cancer, sunscreens have been widely used by beach-goers in recent decades. UV filters contained in sunscreens, however, were recently identified as emerging pollutants in coastal waters since they accumulate in the marine environment with different adverse effects. In fact, exposure to these components was proven to be toxic to most invertebrate and vertebrate marine species. Some UV filters are linked to the production of significant amounts of reactive oxygen species (ROS), such as hydrogen peroxide, and the release of inorganic micronutrients that may alter the status of coastal habitats. Bioaccumulation and biomagnification have not yet been fully addressed. This review highlights recent progress in research and provides a comprehensive overview of the toxicological and ecotoxicological effects of the most used UV filters both on the abiotic and biotic compartments in different types of coastal areas, to gain a better understanding of the impacts on coastal biodiversity

Microstructure and interfacial reactions during active metal brazing of stainless steel to titanium

Microstructural evolution and interfacial reactions during active metal vacuum brazing of Ti (grade-2) and stainless steel (SS 304L) using a Ag-based alloy containing Cu, Ti, and Al was investigated. A Ni-depleted solid solution layer and a discontinuous layer of (Ni,Fe)2TiAl intermetallic compound formed on the SS surface and adjacent to the SS-braze alloy interface, respectively. Three parallel contiguous layers of intermetallic compounds, CuTi, AgTi, and (Ag,Cu)Ti2, formed at the Ti-braze alloy interface. The diffusion path for the reaction at this interface was established. Transmission electron microscopy revealed formation of nanocrystals of Ag-Cu alloy of size ranging between 20 and 30 nm in the unreacted braze alloy layer. The interdiffusion zone of β-Ti(Ag,Cu) solid solution, formed on the Ti side of the joint, showed eutectoid decomposition to lamellar colonies of α-Ti and internally twinned (Cu,Ag)Ti2 inter- metallic phase, with an orientation relationship between the two. Bend tests indicated that the failure in the joints occurred by formation and propagation of the crack mostly along the Ti- braze alloy interface, through the (Ag,Cu)Ti2 phase layer

Internationalizationof Read-Across as a Validated New Approach Method (NAM) for Regulatory Toxicology

Read-across (RAx) translates available information from well-characterized chemicals tothe substance for which there is a toxicological data gap. The OECD is working on case studies to probe general applicability of RAx, and several regulations (e.g. EU-REACH) already allow this procedure to be used to waive new in vivotests. The decision to prepare a review on the state of the art of RAx as a tool for risk assessment for regulatory purposes was taken during a workshop with international experts in Ranco, Italy in July 2018. Three major issues were identified that need optimisation to allowa higher regulatory acceptance rate of the RAx procedure: (i) the definition of similarity of source and target, (ii) the translation of biological/toxicological activity of source to target, in the RAx procedure, and (iii) how to deal with issues of ADMEthat may differ between source and target. The use of new approach methodologies (NAM) was discussed as one of the most important innovations to improve the acceptability of RAx. At present, NAM data may be used to confirm chemical and toxicological similarity. In the future, the use of NAM may be broadened to fully characterize the hazard and toxicokinetic properties of RAx compounds. Concerning available guidance, documents on Good Read-Across Practice (GRAP) and on best practices to perform and evaluatethe RAx process were identified. Here, in particular the RAx guidance, being worked out by the European Commission’s H2020 project EU-ToxRisk, together with many external partners with regulatory experience, is given

Numerical investigations of different tip designs for shroudless turbine blades

Copyright © 2015 by Rolls-Royce plc. The over-tip leakage represents a third of the loss encountered in a typical high-pressure turbine stage. In this paper numerical investigations are carried out to study the effects of different tip designs on the aerodynamic performance and cooling requirements. A parametric design tool is used to conduct an automatic optimisation of the blade tip. The parameterisation allows overhangs to be added to the tip of the aerofoil to form a winglet and in addition a recessed cavity can be applied to produce a squealer tip. The squealer rim may also be opened near the Leading-Edge and the Trailing-Edge of the aerofoil. Flow computations are performed by an in house 3D high fidelity CFD solver for predicting the performance of the component. The solver has been validated with experimental data. Following a preliminary design of experiment, a meta-model is built and an automatic, multi-objective optimisation is carried out to reduce the loss introduced by the over-tip leakage and minimise the heat load on the blade. Three novel designs from the Pareto front have been further analysed. They show a significant improvement over a reference closed squealer in terms of the aerodynamic performance and the heat load. The flow mechanisms providing these benefits are explained in detail