A Creative “Nanotown”. Framing Sustainable Development Scenarios with Local People in Calabria

During a two-year research programme from 2016 to 2018, scholars and students from diferent disciplinary backgrounds engaged with the local community of the town of Gagliato in Calabria, Italy, to co-produce future scenarios of local development. The aim was to enable a transition towards sustainability for a town afected by economic and demographic decline, like many other rural areas of southern Italy, but also be the protagonist of a promising annual summer science festival which had contributed to raising some expectations of change. The research has been designed to enable transdisciplinary knowledge production in the urban feld that could matter for the local community and would ultimately produce a real, positive impact on people’s lives. Despite its broad premises to test innovative learning practices with participating students for an ideal future academia, its concrete outcomes have been deeply ingrained in the local community, becoming part of their discussions of daily life and even informing their political agenda

Surfactant-like Effect and Dissolution of Ultrathin Fe Films on Ag(001)

The phase immiscibility and the excellent matching between Ag(001) and Fe(001) unit cells (mismatch 0.8 %) make Fe/Ag growth attractive in the field of low dimensionality magnetic systems. Intermixing could be drastically limited at deposition temperatures as low as 140-150 K. The film structural evolution induced by post-growth annealing presents many interesting aspects involving activated atomic exchange processes and affecting magnetic properties. Previous experiments, of He and low energy ion scattering on films deposited at 150 K, indicated the formation of a segregated Ag layer upon annealing at 550 K. Higher temperatures led to the embedding of Fe into the Ag matrix. In those experiments, information on sub-surface layers was attained by techniques mainly sensitive to the topmost layer. Here, systematic PED measurements, providing chemical selectivity and structural information for a depth of several layers, have been accompanied with a few XRD rod scans, yielding a better sensitivity to the buried interface and to the film long range order. The results of this paper allow a comparison with recent models enlightening the dissolution paths of an ultra thin metal film into a different metal, when both subsurface migration of the deposit and phase separation between substrate and deposit are favoured. The occurrence of a surfactant-like stage, in which a single layer of Ag covers the Fe film is demonstrated for films of 4-6 ML heated at 500-550 K. Evidence of a stage characterized by the formation of two Ag capping layers is also reported. As the annealing temperature was increased beyond 700 K, the surface layers closely resembled the structure of bare Ag(001) with the residual presence of subsurface Fe aggregates.Comment: 4 pages, 3 figure

Distinct behaviour of localized and delocalized carriers in anatase TiO2 (001) during reaction with O2

Two-dimensional (2D) metallic states induced by oxygen vacancies (VOs) at oxide surfaces and interfaces provide opportunities for the development of advanced applications, but the ability to control the behavior of these states is still limited. We used angle resolved photoelectron spectroscopy combined with density-functional theory (DFT) to study the reactivity of VO-induced states at the (001) surface of anatase TiO2, where both 2D metallic and deeper lying in-gap states (IGs) are observed. The 2D and IG states exhibit remarkably different evolutions when the surface is exposed to molecular O2: while IGs are almost completely quenched, the metallic states are only weakly affected. DFT calculations indeed show that the IGs originate from surface VOs and remain localized at the surface, where they can promptly react with O2. In contrast, the metallic states originate from subsurface vacancies whose migration to the surface for recombination with O2 is kinetically hindered on anatase TiO2 (001), thus making them much less sensitive to oxygen dosing.PostprintPeer reviewe

Serenity: An ATCA prototyping platform for CMS Phase-2

Serenity is an ATCA prototyping platform designed to explore alternative, novel design choices for CMS Phase-2. It uses a newly available interconnect technology from Samtec (Z-RAY) to mount a removable processing unit (FPGA) that should mitigate risk and provides significant flexibility in processing unit choice and connectivity. We explore the pros and cons of using an industry-standard Computer-On-Module running standard Centos Linux and a small service FPGA for low level control. Specially designed Kapton heaters have been used to validate the thermal design of the card and broader considerations of ATCA systems

Reframing China’s heritage conservation discourse. Learning by testing civic engagement tools in a historic rural village

Urban heritage conservation in China has been subject to severe criticism, although there is now a sense of paradigm shift. Charters, declarations and agendas had the merit of filtering down the international discourse on heritage, while more innovative approaches were arising. The UNESCO Historic Urban Landscape recommendation, offers a new angle from which to observe this process of change. The underlying argument of this article is that HUL can provide a platform to achieve greater sustainability in transforming historic sites in China, particularly in rural areas, overcoming, at the same time, the easy shortcut of the East–West discourse of difference in respect to heritage conservation. This is primarily due to the shifting focus from the materiality of heritage to its role in sustainable development with increasing attention on the role played by local communities. By presenting the proposal for the protection of the historic rural village of Shuang Wan in the Jiangsu Province, this paper aims to reflect on this shift showing its advantages but also some of the risks. These are inherent in a discourse of heritage in danger of legitimising mere pro-growth development approaches, if not accompanied by participatory practices considerate of the specific social reality of China

Determination of the (3x3)-Sn/Ge(111) structure by photoelectron diffraction

At a coverage of about 1/3 monolayer, Sn deposited on Ge(111) below 550 forms a metastable (sqrt3 x sqrt3)R30 phase. This phase continuously and reversibly transforms into a (3x3) one, upon cooling below 200 K. The photoemission spectra of the Sn 4d electrons from the (3x3)-Sn/Ge(111) surface present two components which are attributed to inequivalent Sn atoms in T4 bonding sites. This structure has been explored by photoelectron diffraction experiments performed at the ALOISA beamline of the Elettra storage ring in Trieste (Italy). The modulation of the intensities of the two Sn components, caused by the backscattering of the underneath Ge atoms, has been measured as a function of the emission angle at fixed kinetic energies and viceversa. The bond angle between Sn and its nearest neighbour atoms in the first Ge layer (Sn-Ge1) has been measured by taking polar scans along the main symmetry directions and it was found almost equivalent for the two components. The corresponding bond lengths are also quite similar, as obtained by studying the dependence on the photoelectron kinetic energy, while keeping the photon polarization and the collection direction parallel to the Sn-Ge1 bond orientation (bond emission). A clear difference between the two bonding sites is observed when studying the energy dependence at normal emission, where the sensitivity to the Sn height above the Ge atom in the second layer is enhanced. This vertical distance is found to be 0.3 Angstroms larger for one Sn atom out of the three contained in the lattice unit cell. The (3x3)-Sn/Ge(111) is thus characterized by a structure where the Sn atom and its three nearest neighbour Ge atoms form a rather rigid unit that presents a strong vertical distortion with respect to the underneath atom of the second Ge layer.Comment: 10 pages with 9 figures, added reference