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Background: Opportunistic animals such as gulls are often associated with anthropogenic activities [1,2], and therefore highly susceptible to plastic ingestion and stomach chemical leaching [3]. Yet, such chemical process is still poorly studied and there is almost no information regarding potential hazardous effects in animal physiological processes. Even though it was already reported that gulls accumulate Polybrominated Diphenyl Ethers (PBDEs) [4], there is no information linking plastic ingestion with leaching and accumulation of these chemicals in different tissues. Moreover, it is still not fully known how PBDEs affect gulls’ health and stress parameters. Objective: To evaluate: 1) how BDE99 leaches from ingested plastics into tissues, and 2) how this leaching will impact the individuals’ immune status, nervous transmission and physiological stress parameters. Methods: We fed yellow-legged/black-backed gulls (Larus michahellis/Larus fuscus) in captivity with plastic pellets containing BDE99 (PBDE congener). BDE99 was measured in gulls’ brain, preen oil, liver and fat tissues. Erythrocyte sedimentation rate, glutathione peroxidase activity, plasma antioxidant capacity and reactive oxygen metabolites and levels of cholinesterase and acetylcholinesterase activity were measured in blood samples. Cholinesterase activity levels were measured in the brain. Results: Gulls fed with plastics showed significantly higher concentrations of BDE99 in their fat and brain. There was a tendency for plastic-fed gulls to exhibit a more impaired health, yet only values of cholinesterase and acetylcholinesterase in plasma were significatively reduced at the end of the experiment. Cholinesterase in brain also tended to decrease in plastic-fed gulls. Conclusions: Our results indicate a clear relation of plastic ingestion with chemical leaching, a process occurring even if plastic stays in the stomach for a short period of time and that gulls’ health can be affected, particularly gulls’ neurofunction. Our results should have wider implications to understand the impacts of plastic contaminants’ assimilation in vertebrates., Scientific Letters, Vol. 1 No. Sup 1 (2023)

Submitted by Diana Silva (dianasilva@ua.pt) on 2017-07-27T16:03:18Z No. of bitstreams: 1 Microstructural inspection of the M6C phase in heat-treated WC-AISI 304 stainless steel powders_10.1017S1431927614014251.pdf: 300538 bytes, checksum: 67237f46d6587b982d0f579367bc5189 (MD5) Approved for entry into archive by Diana Silva(dianasilva@ua.pt) on 2017-07-27T16:03:40Z (GMT) No. of bitstreams: 1 Microstructural inspection of the M6C phase in heat-treated WC-AISI 304 stainless steel powders_10.1017S1431927614014251.pdf: 300538 bytes, checksum: 67237f46d6587b982d0f579367bc5189 (MD5) Made available in DSpace on 2017-07-27T16:03:40Z (GMT). No. of bitstreams: 1 Microstructural inspection of the M6C phase in heat-treated WC-AISI 304 stainless steel powders_10.1017S1431927614014251.pdf: 300538 bytes, checksum: 67237f46d6587b982d0f579367bc5189 (MD5) Previous issue date: 2015

X-ray diffraction using synchrotron radiation was used for real-time investigation of the phase evolution of Ni/Ti multilayer thin films during annealing. These multilayers were deposited onto Tie6Ale4V substrates by dc magnetron sputtering from pure Ni and Ti targets. The deposition parameters were adjusted in order to obtain a near equiatomic chemical composition and modulation periods (L) below 25 nm. Along the entire thickness of the films, well-defined structures with alternate Ni- and Ti-rich layers are observed, even for L ¼ 4 nm. In this case, a halo characteristic of an amorphous structure is obtained, while for L of 12 and 25 nm the as-deposited thin films are nanocrystalline being possible to identify the (111) Ni and (002) Ti diffraction peaks. The nanolayered structure vanishes during annealing due to interdiffusion followed by reaction. The reaction between Ni and Ti to produce NiTi in the cubic B2 structure occurs in a short delay of time and within a narrow temperature range. For L of 25, 12 and 4 nm, the reaction temperature is close to 320, 350 and 385 C, respectively. For higher temperatures, in addition to the austenitic phase, the NiTi2 phase is identified. The diffusion of Ti from the substrate and Ni towards the substrate could favour the precipitation of NiTi2.

Comunicação apresentada em: EMAS 2013 : 13th European Workshop on Modern Developments and Applications in Microbeam Analysis, Centro de Congressos da Alfândega do Porto, Portugal, 12 to 16 May 2013 A sample of cryolite was studied with a JEOL JXA 8500-F electron microprobe under several operating conditions. A TAP crystal was used to analyse Na and Al and a LDE1 crystal to analyse F. As F and Na are both highly "volatile" elements, special care must be taken during analysis. The measurement order of Na, F and Al is not irrelevant and optimum conditions may also result in different combinations of accelerating voltage, beam current, beam size or counting times. Relevant X-ray signals were recorded in order to investigate the behaviour of the Na Ka and F Ka counts with elapsed time. The incident beam current was also recorded at the same time. In a clear contrast to what has normally been reported in the EPMA analysis of aluminosilicates and silicate glasses, we found that the Na X-ray counts increase with time. This increment of X-rays intensities for sodium in cryolite depends on the operating conditions and is accompanied by a strong migration of fluorine from the beam excitation volume, leading to a decrease in F X-ray counting rates. It was also observed that higher incident beam currents induce higher radiation damage in the mineral. The current instability is consistent with possible electron induced dissociation in the cryolite structure. An analytical protocol was achieved for 6 kV and 15kV accelerating voltage for the correct EPMA analysis of cryolite.

Polystyrene granules were coated by sputtering with an innovative film of stainless steel obtaining this way a composite. To compare results it was necessary to prepare two different composites, mixing polymer granules with steel fibers mechanically in a drum. Microinjection molding is a processing technique that allowed obtaining a representative sample of each composite. Scanning electron microscope (SEM) allowed the characterization of the coating thickness while the dispersion and distribution of metal particles were analyzed by optical microscopy in polarized light. Results showed a uniform thickness of the coating and good dispersion of the reinforcements in the matrix. Electrical and mechanical properties of the composites were characterized by measuring the electrical resistivity and flexural tests. Considerable values of conductivity were exhibited in composites with carbon nanotubes and a slight increase in the modulus of the polymers due to reinforcement incorporation was noticed.