Electroplated Ni/Ni-Co multilayer coatings for higher corrosion-erosion resistance

Erosion-corrosion behaviour of hierarchical structured hydrophobic nickel-cobalt coating, obtained by electrodeposition, was assessed. In situ electrochemical measurements were carried out to study the corrosion resistance and stability during erosion tests. The electrochemical behaviour was related to surface hydrophobicity and its hierarchical structure nature as well as its modification. The pure Ni showed the lowest erosion-corrosion resistance. A smoothing of the hierarchical structure and thus a reduction the hydrophobicity was highlighted. On the other hand, Ni-Co coating even if associated to a lower electrochemical stability showed a more stable hierarchical structure also at high …

Acute and chronic hepatitis in childhood leukemia: a multicentric study from the Italian Pediatric Cooperative Group for Therapy of Acute Leukemia (AIL-AIEOP).

The incidence of acute and chronic liver damage and its relation to hepatitis B virus (HBV) infection was evaluated in 164 consecutive children with acute leukemia seen in ten Italian hemato-pediatric units. Thirteen out of 164 children (7.9%) had acute hepatitis (AH) during treatment, while 8/90 (8.8%) showed an acute exacerbation of liver damage within 6 months after therapy withdrawal. Seven of the 13 children with AH while on therapy were HBsAg positive. In 12/13 cases, liver disease progressed to chronicity. Five of eight children who developed AH after completion of treatment were HBsAg positive. Eighty-nine patients (54.2%) developed biochemical evidence of chronic hepatitis during t…

Influence of anodizing surface treatment on the aging behavior in salt-fog environment of aluminum alloy 5083 to fiber reinforced composites adhesive joints

The present work aims to evaluate how an innovative and eco-friendly anodizing process with tartaric-sulfuric acid (TSA) bath and a pore widening in an aqueous solution of NaOH 0.1 M can improve the durability in marine environment of co-cured adhesive joints between an aluminum alloy (AA 5083) and fiber (i.e., glass or basalt)-reinforced composite substrates. The aging was carried out by exposing samples to salt-fog spray conditions (5 wt.% NaCl) for 30, 60 and 90 days in a climate chamber, in accordance with ASTM B117. In order to get further insights on the aging behaviour of bonded joints, neat matrix was also exposed to the same environment for 60 days. Quasi-static mechanical tests an…

A mathematical description accounting for the superfluous hydrogen evolution and the inductive behaviour observed during electrochemical measurements on magnesium

When electrochemical techniques are used to probe the surface of corroding magnesium with the aim of obtaining quantitative information on the corrosion process, two peculiarities are generally observed: i) with anodic polarization, the rate of hydrogen evolution increases instead of decreasing and ii) during electrochemical impedance spectroscopy measurements, an inductive contribution is often observed at the low-frequency end of the spectra. The presence of these two phenomena clearly has an impact on the methodology that should be applied to correctly estimate corrosion rates from electrochemical data. The aim of this work is to provide a general mathematical description of the corrodin…

Fabrication and Characterization of Chitosan-Heteropolyacid complex as membranes for low temperature H2-O2 fuel cell

In this work we describe an easy procedure to fabricate homogeneous CS-HPA polyelectrolyte films using phosphotungstic acid (PTA) as cross-linking agent. The re action between CS chains and PTA is controlled in order to allow fabricating PEC thin films, that can be easily peeled off from the support, cut to any size and shape, whose thickness can be controlled by setting reticulation and time and/or chitosan concentration

Electronic properties of Al-Nb mixed oxide as a function of their composition

Resistive switching of anodic TiO2-based Memristors

In recent years, memristors have attracted great attention owing to their simple fabrication process, high scalability, good compatibility with the CMOS technology, high switching speed, low power consumption and low cost for next-generation non-volatile memory technology [1]. The basic cell structure of a memristor is an insulator sandwiched between two metal electrodes. Among the materials being studied for memristors fabrication, binary metal oxides, such as TiO2, are most favourable because of their simple constituents, compatible with CMOS processes, and resistive to thermal/chemical damages. Anodizing is a an electrochemical low cost process carried out at room temperature to grow oxi…

Polymeric C3N4 and O-doped C3N4: Photoelectrochemical and EPR Features for Selective Photocatalytic Oxidation of Alcohols to Aldehydes

Polymeric C3N4 and O-doped C3N4: Photoelectrochemical and EPR Features for Selective Photocatalytic Oxidation of Alcohols to Aldehydes

The Effect of Electronic Properties of Anodized and Hard Anodized Ti and Ti6Al4V on Their Reactivity in Simulated Body Fluid

The electronic properties of barrier and porous layers on Ti and Ti6Al4V were studied. Barrier anodic oxides grown to 40 V on Ti and on Ti6Al4V are both n-type semiconductors with a band gap of 3.3 eV and 3.4 eV respectively, in agreement with the formation of amorphous TiO2. Anodizing to 200 V at 20 mA cm−2 in calcium acetate and β-glycerol phosphate disodium pentahydrate leads to the formation of Ca and P containing porous films with a photoelectrochemical behaviour dependent on the metallic substrate. A band gap of 3.2 eV and the flat band potential of −0.5 V vs Ag/AgCl were measured for the porous oxide on Ti, while optical transitions at 2.15 eV and a significantly more positive flat b…

Anodizing of aluminium and AA 2024-T3 alloy in chromic acid: Effects of sulphate on film growth

Chromic acid anodizing is important for the corrosion protection of aerospace aluminium alloys. Previous study has demonstrated that SO42 − impurity in the chromic acid affects the film growth on aluminium at a voltage of 100 V. The present work further investigates aluminium and extends the study to industrial anodizing conditions (Bengough-Stuart (B-S) process) and to the AA 2024-T3 alloy. It is shown that SO42 − concentrations between ~ 38–300 ppm reduce the film growth rate for aluminium anodized at 100 V in comparison with an electrolyte than contains ≤ 1.5 ppm SO42 −, whereas ~ 1500–3000 ppm SO42 have an opposite effect and lead to an unstable pore diameter. Under the B-S process, the…