Long term directional wave recording in the Northern Adriatic Sea

We report on the instrumental system used on an oceanographic tower for the directional measurement of wind waves. The associated time series is one of the longest ones in the world. After a compact description of the instrumental part, we present some long term statistics of the wave conditions in the Northern Adriatic Sea. Then we discuss the applications of the results and the possible evolution of the system

Motion dynamics of Si (100) positive and negative islands under electromigration and thermomigration

International audienceMass transport processes play an important role in nano devices. They determine the morphology and the stability of a working device, and eventually its lifetime. When a direct electric current is applied to a material, it affects the mass transport by adding a bias to the atomic diffusive motion. This effect, called electromigration, can play an important role on the dynamics and the morphological stability of nanostructures at surfaces. In this work we have studied the motion of single-step holes and islands under the effect of an electric field on Si(100), in real time, by Low Energy Electron Microscopy (LEEM). The details of the motion depend on the strong diffusion anisotropy of the Si dimer rows. Studying the velocity and the shape of the nanostructures, we discuss a model to explain and guide the motion of holes and islands. Electron energy lower than 20 eV High imaging dynamics (0.1 s per image) LEEM This work was performed in the framework of the ANR grant HOLOLEEM (ANR-15-CE09-0012). We are grateful to B. Ranguelov and M. Michailov for stimulating discussions had in the framework of the PHC Rila project (38663TB)) project. The poster is based on the paper: "2D nanostructure motion on anisotropic surfaces controlled by electromigration", S. Curiotto

Microplastic Contamination in Protected Areas of the Gulf of Venice

We investigated the concentration and composition of plastics in 7 Special Areas of Conservation (SACs) from the Gulf of Venice (northern Adriatic Sea). A total of 42 sediment samples were analyzed from 21 sites from 2017 to 2018. All sites except one were found to be polluted by plastics, with density ranging between 2250 and 28.4 items kg−1. Microplastics ranged from 100 to 61.6% of the collected plastics. Fragments were more represented than filaments. The greatest plastic concentrations were generally recorded in western SACs. Identification through FT-IR spectroscopy evidenced the presence of 8 polymer types: in western SACS, the majority were low-density polymers (PE, PP, PS, and TPU), while in eastern SACs they were high-density polymers (PET, nylon, and PVC). In addition to the role of large rivers (all on the western side of the Gulf) in conveying plastics into the sea, a possible role of the cyclonic water circulation of the northern Adriatic Sea on distribution and composition of plastics along the Gulf coasts is likely

Solidification of Al-Sn-Cu based immiscible alloys under intense shearing

The official published version of the Article can be accessed from the link below - Copyright @ 2009 The Minerals, Metals & Materials Society and ASM InternationalThe growing importance of Al-Sn based alloys as materials for engineering applications necessitates the development of uniform microstructures with improved performance. Guided by the recently thermodynamically assessed Al-Sn-Cu system, two model immiscible alloys, Al-45Sn-10Cu and Al-20Sn-10Cu, were selected to investigate the effects of intensive melt shearing provided by the novel melt conditioning by advanced shear technology (MCAST) unit on the uniform dispersion of the soft Sn phase in a hard Al matrix. Our experimental results have confirmed that intensive melt shearing is an effective way to achieve fine and uniform dispersion of the soft phase without macro-demixing, and that such dispersed microstructure can be further refined in alloys with precipitation of the primary Al phase prior to the demixing reaction. In addition, it was found that melt shearing at 200 rpm and 60 seconds will be adequate to produce fine and uniform dispersion of the Sn phase, and that higher shearing speed and prolonged shearing time can only achieve minor further refinement.This work is funded by the EPSRC and DT

Valutazione dell'efficacia delle aree marine protette nel mitigare la vulnerabilità e capacità adattativa di comunità bentoniche in scenari climatici futuri

The anthropogenic climate change is causing, globally and locally, loss of biodiversity and regression of priority habitats, making conservation and restoration of species and the ecosystem services they provide the greatest challenges of our time. According to future climate projections of temperature increases (RCPs) and socioeconomic changes (SSPs), finding environmentally and economically sustainable actions, strategies and Nature Based Solutions for climate change adaptation and mitigation is mandatory. Firstly, it is important to understand what the vulnerability and adaptive capacity of relevant species and their relative level of risk will be by the end of the century. The aim of this work is to evaluate the climate risk of some organisms of benthic communities and the mitigation effect of NBS in future climatic and socio-politic scenarios. Climate Risk Assessment is a useful tool to assess and understand the cause/effect relationship between climate change and their associated risk. It is built around the AR5/6 of IPPC guidelines, according to which the risk of a given system or species results from the combination of three dimensions: Hazard, Exposure and Vulnerability, the latter estimated as a function of its Sensitivity and Adaptive Capacity. It investigates three climate hazards (increasing temperature, marine heat waves and ocean acidification) and two human hazards (boat anchoring and nutrient loading) in order to understand the magnitude of exposure and to asses the adaptive capacity of five taxa (Posidonia oceanica, Cystoseira s.l., encrusting corallinaceae algae, Epinephelus marginatus, Paracentrotus lividus) in the presence or absence of NBS, namely the Marine Protected Areas. Then, it asseses the potential mitigation capacity of NBS to mitigate the effects of climate change. Both the Risk and the MPA Mitigation Capacity have been assessed considering two time slices (mid term and long term future) in three different socioeconomic scenarios, based on the RCPs and SSPs projections (Global Sustainability, National Enterprise and World Markets). The results clearly show an overall High values of Risk and a Low Mitigation Capacity of MPAs. Il cambiamento climatico antropogenico sta causando, globalmente e localmente, la perdita di biodiversità e la regressione di habitat prioritari, rendendo la conservazione e il ripristino delle specie e dei servizi ecosistemici da esse forniti la sfida più grande dei nostri tempi. Stando alle proiezioni climatiche future di aumento delle temperature (RCP) e di cambiamenti socioeconomici (SSP), è indispensabile trovare strategie e Soluzioni Basate sulla Natura che siano sostenibili dal punto di vista ambientale ed economico per l'adattamento e la mitigazione dei cambiamenti climatici. In primo luogo, è importante capire quali saranno la vulnerabilità e la capacità adattativa di specie d'interesse e il relativo livello di rischio entro fine secolo. Lo scopo di questo lavoro è valutare il rischio climatico di alcuni organismi di comunità bentoniche e l'effetto mitigativo delle NBS in scenari climatici e socio-politici futuri. La valutazione del rischio climatico è uno strumento utile per valutare e comprendere la relazione causa/effetto tra i cambiamenti climatici e il rischio associato. Si basa sulle linee guida AR5/6 dell'IPPC, secondo le quali il rischio di un determinato sistema o specie risulta dalla combinazione di tre dimensioni: Pericolo, Esposizione e Vulnerabilità, quest'ultima stimata in funzione della Sensibilità e della Capacità Adattativa. Il CRA considera tre rischi climatici (aumento della temperatura, ondate di calore marine e acidificazione degli oceani) e due rischi antropici (carico di nutrienti e ancoraggio delle imbarcazioni) per comprendere l'entità dell'esposizione e valutare la capacità adattativa di cinque taxa (Posidonia oceanica, Cystoseira s.l., alghe corallinacee incrostanti, Epinephelus marginatus, Paracentrotus lividus) in presenza o in assenza di NBS, ovvero le aree marine protette. Quindi, valuta la potenziale capacità di mitigazione delle NBS nell'attenuare gli effetti del cambiamento climatico. Sia il Rischio che la Capacità Mitigatrice delle AMP sono stati valutati considerando due orizzonti temporali (futuro a medio e lungo termine) in tre diversi scenari socioeconomici, basati sulle proiezioni RCP e SSP (Sostenibilità globale, Svillupo Nazionale e Mercati Mondiali). I risultati mostrano chiaramente un valore complessivo di rischio elevato e una bassa capacità di mitigazione delle AMP