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Conventional high-chromium ferritic / martensitic steels, such as T91 and AISI 316 L as well as the new oxide dispersed strengthened (ODS) steels, i.e. Fe-Cr (ferritic or martensitic) with a fine Y2O3 dispersion, are promising candidates as structural materials for applications in aggressive environments. In order to improve the efficiency and lifetime of structural materials for liquid metal fast reactor (LMFR), where liquid lead (Pb) is used as coolant, the investigations are currently focused on the interfacial phenomena occurring at the liquid Pb/steel interfaces. The better understanding of the interfacial phenomena is the key issue for the selection of structural materials meeting the requirements of the demanding application. In the present work, a fundamental study on the wetting characteristics and the interfacial phenomena of liquid Pb in contact with T91, AISI 316L, ODS- 12Cr and ODS-14Cr steels over the temperature range 550�820�C and under different oxygen containing atmospheres is reported.

Several pufferfish species belonging to the Tetraodontidae family are currently present in the Mediterranean Sea. Since 2013 Lagocephalus sceleratus is increasingly reported also along Italian coasts, where other two species of less concern, Lagocephalus lagocephalus and Sphoeroides pachygaster, have also occured since a long time. This study represents one of the first attempts to sistematically describe the occurrence in the Mediterranean, and in particular along Italian coasts, of the three aforesaid species, in order to characterize an emerging public health hazard. Reports were searched in scientific articles and dedicated online databases. The following data were collected: number of specimens and type of record, geographical location and date of report, fish size, depth and type of seabed. Overall, at least 111079 individuals of the three species were found in the Mediterranean Sea, including 110237 specimens of L. sceleratus (since 2003), 126 of L. lagocephalus (1878–2017) and 716 of S. pachygaster (1979–2017). The evident differences confirm the invasive character of the toxic Lessepsian immigrant L. sceleratus, the species of main public health concern. Despite this species was recorded along Italian coasts in low numbers (0.08% of the total individuals of L. sceleratus) and its current distribution is limited to southern regions, the picture could change rapidly. Moreover, the collected data show that most L. sceleratus specimens have a large size and are mainly caught by commercial fishing gears. These factors may increase the risk of this species entering the seafood chain with serious consequences for consumers’ health. Results suggest that the presence of L. sceleratus should be strictly monitored. Institutional measures should be implemented to inform people as regards a new hazard that has the potential to affect the Italian seafood chain.

In this work, we have analyzed the key features of Rickettsia spp. maintenance in Dermacentor marginatus ticks in four regions of the northern Mediterranean area, where extensive investigations are currently lacking. For this purpose, 380 adult D. marginatus ticks were collected from vegetation and wild ungulates during a 3-year study. A host-vector-pathogen interaction approach was applied to investigate the key components of the disease systems and evaluate their respective weight in the intensity of infection in natural foci. A high variability in the R. slovaca infection rate among sampling sites was observed, whereas R. raoultii was sporadically present and at low infection rates. Dermacentor marginatus presence was confirmed in all the investigated regions. The local wild boar population showed a strong association with adult D. marginatus ticks. The results of this investigation suggest that wild boars not only maintain D. marginatus populations by feeding adult ticks, but may also have a potential role in the eco-epidemiology of rickettsioses, as carriers of rickettsiae-infected ticks. The public health implications of these results are discussed.

The knowledge of thermophysical properties of liquid Co-Si alloys is a key requirement for manufacturing of composite materials by infiltration method. Despite this need, the experimental and predicted property data of the Co-Si system are scarce and often inconsistent between the various sources. In the present work the mixing behaviour of Co-Si melts has been analysed through the study of the concentration dependence of various thermodynamic, surface (surface tension and surface composition) and structural properties (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the framework of the Compound Formation Model (CFM) and Quasi Chemical Approximation for regular solutions (QCA). In addition, the surface tension of the Co22·5Si77.5 (in at%) eutectic alloy, that is proposed to be used as the infiltrant, has been measured by the pendant drop method at temperatures ranging from 1593 to 1773 K. The results obtained were discussed with respect to both, temperature and concentration, and subsequently compared with the model predictions and literature data.

Eustrongylides spp. are cosmopolitan parasitic nematodes with several freshwater fish species as intermediate or paratenic hosts, rarely reported as zoonotic agents. This work aims to report, for the first time, the occurrence of this parasite in specimens of big scale sand smelt (Atherina boyeri) caught in the lake Massaciuccoli (Northwest Tuscany, Italy). Totally 3317 specimens of A. boyeri were collected in three different samplings (August–October 2019). Fish were visually examined and then submitted to artificial digestion. Visible parasites were collected and counted after both procedures, then they were identified to genus level by microscopic examination and to species level by molecular analysis of the ITS gene region. Overall, 75 nematodes identified as larval stages of Eustrongylides excisus were found (P: 2.3% 95% CI 1.8–2.8; MA: 0.02; MI: 1), in the viscera and in the muscle. A. boyeri is a highly appreciated fish species in several Italian areas as well as in various Mediterranean countries. Beside an epidemiological interest due to its role in the parasite cycle, the report of E. excisus in the study area arises possible quality and public health issues. Therefore, also considering the method of preparation of A. boyeri and that lately the increasing consumption of raw fish has also targeted freshwater fish species, it is essential to communicate the presence of this hazard and the need of applying appropriate sanitary measures to all FBOs along the supply chain and to consumers.

The corrosion behaviour of oxide dispersion strengthened (ODS) steels with different chromium contents (9, 12 and 14 wt% Cr) is investigated in stagnant liquid lead at a temperature of 973 K for 2000 h. Under an oxygen concentration close to the passivation domain (i.e. Co ~10-5-10-4 wt% O), neither an internal oxidation zone in the steel matrix, nor dissolution attack caused by liquid lead or its penetration is observed. Indeed, thin layers of chromium rich oxides with different compositions are detected.

Oxide dispersion-strengthened (ODS) steels are being studied as potential materials for future Generation IV concepts of Nuclear Fast Reactors. In particular, the use of heavy liquid metals (HLM), lead and lead bismuth eutectic alloy, is foreseen as coolant and target. However, most of the structural materials used traditionally, suffer severe damage when in contact with HLMs. Structural materials such as the austenitic 316L and the ferritic–martensitic T91 steels have been considered for operation at temperature lower than 823 K. On the other hand, for operations at elevated temperature and under severe neutron exposure environment, the ODS steels are taken into account and currently studied. In the frame of the FP7-GETMAT (Generation IV and Transmutation Materials) project, ODS steels containing 12 wt% Cr were tested in different conditions and environments, comparing experimental techniques and results. This paper reports the results of the study on the behaviour of the 12Cr-ODS steel in contact with molten lead at the temperature of 923 K. The corrosion tests were performed both in a static cell (CorAL) and in flowing conditions, in a natural convection loop (COLONRI II), in Pb, for an exposure time up to 2000 h. The microstructure analysis of the specimens was done before and after the corrosion tests. The results of the corrosion experiments in both experimental facilities are described and the characteristics of the oxides developed on the 12Cr-ODS steel are discussed.

The systems containing highly reactive element such as Ti are the most difficult to be determined experimentally and therefore, it is often necessary to estimate the missing values by theoretical models. The thermodynamic data of the Al–Ti system are scarce, its phase diagram is still incomplete and there are very few data on the thermophysical properties of Al–Ti melts. The study on surface, dynamic and static structural properties of liquid Al–Ti alloys has been carried out within the framework of the Compound Formation Model. In spite of the experimental difficulties, the surface tension of liquid Al–2 at.%Ti alloy has been measured over a temperature range by the pinned drop method.

The mass transfer phenomena between a liquid metal and the surrounding gas phase play an important role in several technological processes: the existence of oxygen fluxes can strongly affect the properties of the gas–liquid interface. Here, known kinetic criteria will be connected to saturation laws and arranged in a series of tests easily applicable to real cases in order to forecast the steady configuration of the phases. The case of tin will be discussed.

Based on the phase diagram evidence of the existence of three intermetallic compounds, the phenomenon of compound formation in Ni–Ti liquid alloys has been analysed through the study of surface properties (surface tension and surface composition), dynamic properties (chemical diffusion) and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short range order parameter) in the frame of compound formation model (CFM).

In previous works a theoretical analysis was developed for the interactions of a pure liquid metal and an oxidizing atmosphere in both an inert gas carrier and a vacuum. In particular, the effects of oxidation reactions taking place in the gas phase and the evaporation of the condensed oxides were considered. In both cases the presence of oxidation phenomena contributed to maintaining interface cleanness and then strongly affected the shape of the boundary separating the oxidation and de-oxidation regimes. In this work we present a more general physico-mathematical analysis, which is extended to liquid binary alloys and their oxides. The theoretical results obtained indicate that the behaviour of the alloy towards oxygen tends to be similar to that of the less oxidizable component: so the existence of a volatile oxide can often prevent surface oxidation even if the corresponding metal is present in low percentages.

The main objective of this work is to determine the wetting behaviour of lead-free solders on copper substrates in view of their applications in electronic industry. The wetting behaviour of X–In–Sn (X=Au, Bi) ternary molten alloys in contact with copper has been studied and compared with the corresponding behaviour of their binary subsystems with a particular attention to the In–Sn/Cu system. The contact angle measurements on Cu-plates were performed by using a sessile drop apparatus. The solder/copper interface was characterised by the SEM-EDS analysis.

The wetting phenomena of molten alloy/ceramic substrate depend on the bonding characteristics of liquid alloys and ceramics as well as on the magnitude of interactive forces at the interface. According to this, the first step of this investigation is to determine the surface properties of Ag–Cu, Ag–Ti and Cu–Ti liquid alloys. The energetics of mixing in liquid alloys has been analysed through the study of surface properties (surface tension and surface composition) and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the frame of statistical mechanical theory in conjunction with the quasi-lattice theory (QLT). The results obtained for these binary systems have been extended to the ternary Ag–Cu–Ti system. Combining the Young and the Dupre equations, the computed results of surface tension together with contact angle data have been used to calculate the work of adhesion and, in the case of non-reactive wetting, the interfacial tension between the solid substrate and the liquid alloys over the whole concentration range. The evaluation of the interfacial tension values is determined from calculated and measured data using solid surface tension data from literature. These results provide more information on the characteristics of metal–ceramic systems, and are therefore useful in guiding experiments, or in predicting the surface properties of metallic systems with similar characteristics as well as their wetting behaviour in contact with ceramic materials.

Auger measurements of the surface composition have been performed on solid and molten Pb-5at%Sn alloys. They confirm the theoretical predictions that, in the absence of oxygen, liquid or solid alloys exhibit no significant surface segregation. On the contrary, surface composition measurements and simultaneous surface tension measurements clearly show that oxygen adsorption strongly affects the segregation of tin at the liquid-vapour interface. This surface enrichment is driven by the contribution of the reaction free energy and of the products surface tension.

The mixing behaviour of liquid Sb–Sn alloys has been described in terms of energetics and structure through the study of their thermodynamic, surface, transport and structural properties by using the Complex Formation Model (CFM) in the weak interaction approximation and by postulating SbSn chemical complexes as energetically favoured. The new Sb–Sn surface tension experimental data, obtained by the pinned drop method at temperatures ranging from 513 to 1023 K , have been analysed in the framework of the CFM and compared with the calculated values as well as with the corresponding literature data. The structural characteristics of Sb–Sn melts are described by the two microscopic functions, i.e. the concentration fluctuations in the long-wavelength limit and the Warren–Cowley short-range order parameter.

The present work was carried out in the framework of the study of new lead-free solder alloys for technical applications in electronic devices. In the focus of this characterisation the wetting behaviour of several Sn-rich alloys belonging to the In–Sn, Au–Sn and Cu–Sn systems has been studied by measuring the contact angle variations on Cu and Ni substrates as a function of time and temperature. The interface between the alloy and the substrate has been analysed by the use of optical microscopy and scanning electron microscopy combined with energy-dispersive X-ray spectrometry in order to study the reaction between the alloy and the solid substrate and the possible formation of different compounds at the interface. A remarkable effect of the two different substrates on the behaviour of the contact angle as a function of temperature and on the morphology of the interface between the liquid solder and the solid substrate was observed for the In–Sn and Cu–Sn, while the Au–Sn system shows a very similar wetting behaviour on Cu and Ni.

Using the monolayer model, a thermodynamic approach is suggested in order to compare the surface reactivity to the volume reactivity under both equilibrium and nonequilibrium conditions (sorption and chemical processes). Capillary parameters, such as surface tension and surface dilation, have a direct influence on the efficiency of chemical reactions and on their stability.

The influence of oxygen on the surface tension of liquid metals is a topic of undoubted interest as the formation of oxide films, or even oxygen contamination of the metal interface, represents the main source of error in determining the surface tension. The evaluation of gas-atmosphere mass exchanges under stationary conditions allows the evaluation of an effective oxygen pressure at which the oxidation of metal becomes evident. This effective oxygen pressure can be considered as a property of the system and, according to experimental evidence, can be many orders of magnitude greater than the equilibrium pressure. The measurement of the surface tension is a good way of studying interface properties, their temporal change and their connections to transport and reaction rates. This paper represents a review of a work undertaken with the aim of understanding oxygen mass transport at the liquid metal surface in relation to the study of capillary phenomena at high temperature.

The surface tension and the density of some gold alloys have been measured and their wetting behaviour investigated in relation to different ceramic supports. Relationships between surface tension and density as a function of temperature are proposed.

A theoretical model on oxygen transport at the surface of liquid metals has been validated by dynamic surface tension measurements performed on liquid Indium as test metal. The oxygen contamination conditions have been obtained at different oxygen partial pressures under both low total pressure (Knudsen regime) and inert atmospheric pressure (Fick regime) conditions, confirming that an oxide removal regime occurs under an oxygen partial pressure much higher than the equilibrium one (the "Effective Oxidation Pressure"). Experimental results are reported which give a further insight on the relative importance of the various processes due to the oxygen mass transport between the liquid metal and the gas phase. The critical aspects involved in surface tension measurements of liquid metals, related to the problem of liquid metal-oxygen interactions, are also underlined.