13 research outputs found
Optimisation of Thiourea Concentration in a Decorative Copper Plating Acid Bath Based on Methanesulfonic Electrolyte
The role of thiourea as an organic additive in the nucleation and growth mechanism was studied for copper deposition and its application in the decorative electroplating and fashion accessory industries. The bath was designed to reduce the environmental and ecological impacts using methanesulfonic acid as electrolyte as an alternative to alkaline cyanide baths. We evaluated the nucleation and growth mechanism of copper exploiting voltametric and chronoamperometric measurements with a brightener concentration ranging from 0 to 90 ppm. We used the Scharifker– Hills model to estimate the type of nucleation mechanism after progressive addition of thiourea. Scanning electron microscope was employed for surface analysis and morphological characterisation of the nuclei. We verified that progressive nucleation is a key step in the obtainment of a shiny and homogeneous copper film, but an excess of thiourea could cause parasitic adsorption reactions on the surface of the substrate. X-ray fluorescence spectroscopy was used for the thickness determination of the copper deposits and the electrodeposition efficiency correlated to thiourea concentration. Finally, the optimal concentration of thiourea was assessed to be 60 ppm for the used formulation of copper plating
MWCNTs-Supported Pd(II) Complexes with High Catalytic Efficiency in Oxygen Reduction Reaction in Alkaline Media
Rank-Rankl-Opg Axis in Multiple Sclerosis: The Contribution of Placenta
Women with multiple sclerosis (MS) can safely become pregnant and give birth, with no side effects or impediments. Pregnancy is generally accepted as a period of well-being in which relapses have a softer evolution, particularly in the third trimester. Herein, we hypothesized that the placenta, via its “secretome”, could contribute to the recognized beneficial effects of pregnancy on MS activity. We focused on a well-known receptor/ligand/decoy receptor system, such as the one composed by the receptor activator of nuclear factor-kB (RANK), its ligand (RANKL), and the decoy receptor osteoprotegerin (OPG), which have never been investigated in an integrated way in MS, pregnancy, and placenta. We reported that pregnancy at the term of gestation influences the balance between circulating RANKL and its endogenous inhibitor OPG in MS women. We demonstrated that the placenta at term is an invaluable source of homodimeric OPG. By functional studies on astrocytes, we showed that placental OPG suppresses the mRNA expression of the CCL20, a chem-okine responsible for Th17 cell recruitment. We propose placental OPG as a crucial molecule for the recognized beneficial effect of late pregnancy on MS and its potential utility for the development of new and more effective therapeutic approaches
An XRPD and EPR spectroscopy study of microcrystalline calcite bioprecipitated by Bacillus subtilis
We report in this study the first XRPD and EPR spectroscopy characterisation of a biogenic calcite, obtained from the activity of the bacterium Bacillus subtilis. Microcrystalline calcite powders obtained from bacterial culture in a suitable precipitation liquid medium were analysed without further manipulation. Both techniques reveal unusual parameters, closely related to the biological source of the mineral, i.e., to the bioprecipitation process and in particular to the organic matrix observed inside calcite. In detail, XRPD analysis revealed that bacterial calcite has slightly higher c/a lattice parameters ratio than abiotic calcite. This correlation was already noticed in microcrystalline calcite samples grown by bio-mineralisation processes, but it had never been previously verified for bacterial biocalcites. EPR spectroscopy evidenced an anomalously large value of W6, a parameter that can be linked to occupation by different chemical species in the next nearest neighbouring sites. This parameter allows to clearly distinguish bacterial and abiotic calcite. This latter achievement was obtained after having reduced the parameters space into an unbiased Euclidean one, through an isometric log-ratio transformation. We conclude that this approach enables the coupled use of XRPD and EPR for identifying the traces of bacterial activity in fossil carbonate deposits
Morphology and composition of Cu2S ultra-thin films deposited by E-ALD
CIGS are very promising semiconducting materials for solar energy conversion, but at the same time are considered unfavorable for the large scale exploitation. Thus, the scientific community is focusing attention on new compounds based on economic and low-environmental impact elements such as Cu, Sn, Fe and Zn. Exploiting electrodeposition by means of Electrochemical Atomic Layer Deposition (E-ALD) it is possible to grow ultra-thin films of semiconductors with tunable properties, such as copper sulphides films grown on Ag(111) single crystals. Considering the E-ALD scheme one would expect a CuS hexagonal structure (covellite) with no any important electronic properties, but recently operando Surface X-Ray Diffraction (SXRD) studies were able to show the presence of a chalcocite phase (Cu2S). In this communication we report a morphological and compositional study, confirming the composition and morphology expected from the results of the SXRD operando measurements pointing to the growth of Cu2S by means of E-ALD
The Amphipod Talitrus saltator as a bioindicator of human trampling on sandy beaches
The present paper assesses the use of the supralittoral amphipod Talitrus saltator as a bioindicator of the effects of human trampling on the supralittoral sandy band. Samplings in delimited areas were carried out at sites subjected to different human impact. The results showed a strong negative correlation between the number of swimmers and the sandhopper population density, while there was no clear relationship between sandhopper abundance and the other factors considered: granulometry, compactness and organic carbon content of the sand, and trace metal contents in the sand and sandhoppers. A field test of trampling conducted in a confined space showed its direct negative effect on sandhopper survival. However, trace metal analysis confirmed the ability of T. saltator to bioaccumulate some elements (Hg, Zn, Cu, Cd). Our study demonstrates that T. saltator is a good bioindicator of human impact in the supralittoral zone of sandy shores. (C) 2008 Elsevier Ltd. All rights reserved
AMPHIBIAN CNR experimental data MnZn ferrite HP-FAST_JNanosciNanotechnol2019 [Dataset]
Peer reviewe
High Density Nanostructured Soft Ferrites Prepared by High Pressure Field Assisted Sintering Technique
[EN] The synthesis of highly compacted, nanostructured soft magnets is highly desirable due to their promising properties for the development of electronic devices working at frequency higher than 2 MHz. In this work we investigated the potentiality of High Pressure Field Assisted Sintering Technique (HP-FAST). To this aim, we first synthesized soft Mn–Zn ferrite magnetic nanoparticles (MNPs) through an easy-scalable, eco-friendly strategy based on aqueous co-precipitation in basic media, starting from transition metal chlorides. Powder X-ray diffraction (PXRD) and Transmission Electron Microscopy (TEM) analyses evidenced the formation of crystalline nanoparticles with the cubic spinel structure and average crystal size of 7.5 nm. Standard magnetometric measurements showed a saturation magnetization value of ca. 56 emu/g and no magnetic irreversibility at room temperature. The MNPs were then compacted applying an uniaxial pressure over a toroidal shaped die. In order to obtain a material with a density close to the bulk one, the as-prepared green toroids underwent either a classic sintering treatment, obtaining a microstructured system, or to High Pressure Field Assisted Sintering Technique (HP-FAST), which allowed for preserving the nanostructure. The relative permeability and core losses of the toroidal samples were evaluated in the frequency range 1–2 MHz using an in-house built setup. The comparison of the behavior of samples obtained by the two different sintering approaches showed the nanostructured samples had a much smaller relative magnetic permeability (ten times lower than the microstructured sample) and, consequently, higher core losses. However, when samples with similar μr were compared, a significant decrease of core losses at the larger frequencies was observed. This result suggests HP-FAST is a very promising approach to prepare high density nanostructured soft magnetic materials.Research supported by H2020 AMPHIBIAN (n. 720853) and Regione Lombardia
INSTM, “Motorsport” projects.Peer reviewe
The Smart City and the Creation of Local Public Value
none1The distinctive feature of local authorities is the creation of public value in a financially sustainable way. In other words, they are expected to meet effectively the public needs of citizens, generating a positive spread between social benefits and costs and thus contributing to the prosperity of their community of reference (i.e. their constituency). At the same time, they are expected to pursue financial stability by efficiently using the increasingly scarce and therefore precious public resources.
The fulfillment of this function is very complex, due to both the growing proliferation of public needs and the progressive lack of available resources, but also because it is significantly affected by the roles played by many other actors, including citizens, businesses, other public authorities and not-for-profit organizations.
To address this difficulty, many local authorities state, in their strategic plans, that they wish to become smart. A smart city, in fact, identifies an urban environment actively engaged in improving the quality of life of its citizens and in pursuing sustainable socio-economic development, thanks to the wide and innovative use of information and communication technology.
However, so far the concept of smart city, although widely used, does not have a consistent meaning and therefore needs to be deepened and better defined. More precisely, this paper seeks to identify fields of action in which the city can be smart, analyzing the potential benefits to quality of life, environmental protection and economic development, but also looking into the possible obstacles and potential solutions in the relationship between the local authority and other actors in the social system.
Moreover, even the application of the smart city model is quite varied. In this regard, the paper aims to describe the state of the art of Italian regional capitals, seen as a significant sample of large and medium-size cities in the country, analyze their common and different features, strengths and weaknesses, and suggest some solutions to overcome weaknesses and exploit strengths.
Therefore, the aim of this paper is two-fold. On a theoretical level, it aims to contribute to the smart city definition and critically analyze the relationship between this concept and the creation of local public value. On a practical level, it intends to verify the adoption of the smart city model by a significant sample of large and medium-size Italian cities, in order to draw useful indications of perspective. In essence, the paper aims to provide a critical and empirically informed analysis of the potential success, but also possible failure of the smart city projects.Federico FontanaFontana, Federic