811 research outputs found
Industrial policies in Europe: an introduction
As guest editors of this Special Issue of PE/JEP we have selected a small number of rather detailed assessment of contemporary history of domestic industrial policies in the international context. The four papers included in this Special Issue can be seen as three case studies of
“sectoral” innovation policies (broad band, wind energy, biotechnology) with a strong emphasis on country institutional features and policy instruments, together with one “horizontal” case of industrial policy in a specific country context (innovative startups in Italy).
The heterogeneous theoretical background (industrial organization, evolutionary theory of the
firm, economics of innovation, development) provides a somewhat unifying hidden thread of
these case studies, without becoming a subject of analysis per se. This approach has been our
intentional editorial choice and we are fully aware of its limitations.
After very short non-technical summaries of the four papers (Section 1) we try to present a
rather synthetic assessment of our personal views (largely shared among us even with partial
minor disagreements) about the increasingly hot debate on the nature, limitations and desirable
perspectives of industrial policy today. We argue for a non-ideological forward-looking role of
governments as active players in helping domestic entrepreneurial resources not only to fully
exploit inherited comparative advantages but also to face structural uncertainties and discover
own potential competitive advantages in a rapidly changing international context (Section 2)
Electron-Phonon Coupling in Charged Buckminsterfullerene
A simple, yet accurate solution of the electron-phonon coupling problem in
C_{60} is presented. The basic idea behind it is to be found in the
parametrization of the ground state electronic density of the system calculated
making use of ab-initio methods, in term of sp hybridized orbitals.
This parametrization allows for an economic determination of the deformation
potential associated with the fullerene's normal modes. The resulting
electron-phonon coupling constants are used to calculate Jahn-Teller effects in
C_{60}^-, and multiple satellite peaks in the corresponding photoemission
reaction. Theory provides an accurate account of the experimental findings.Comment: 11 pages, 3 figures. Accepted for publication in Chem. Phys. Let
Tailoring the magnetic ordering of the Cr4O5/Fe(001) surface via a controlled adsorption of C60 organic molecules
We analyse the spinterface formed by a C60 molecular layer on a Fe(001) surface covered by a two-dimensional Cr4O5 layer. We consider different geometries, by combining the high symmetry adsorption sites of the surface with three possible orientations of the molecules in a fully relaxed Density Functional Theory calculation.We show that the local hybridization between the electronic states of the Cr4O5 layer and those of the organic molecules is able to modify the magnetic coupling of the Cr atoms. Both the intra-layer and the inter-layer magnetic interaction is indeed driven by O atoms of the two-dimensional oxide. We demonstrate that the C60 adsorption on the energetically most stable site turns the ferromagnetic intra-layer coupling into an antiferromagnetic one, and that antiferromagnetic to ferromagnetic switching and spin patterning of the substrate are made possible by adsorption on other sites
Quasiparticle Electronic structure of Copper in the GW approximation
We show that the results of photoemission and inverse photoemission
experiments on bulk copper can be quantitatively described within
band-structure theory, with no evidence of effects beyond the
single-quasiparticle approximation. The well known discrepancies between the
experimental bandstructure and the Kohn-Sham eigenvalues of Density Functional
Theory are almost completely corrected by self-energy effects.
Exchange-correlation contributions to the self-energy arising from 3s and 3p
core levels are shown to be crucial.Comment: 4 pages, 2 figures embedded in the text. 3 footnotes modified and 1
reference added. Small modifications also in the text. Accepted for
publication in PR
Elementary structural building blocks encountered in silicon surface reconstructions
Driven by the reduction of dangling bonds and the minimization of surface
stress, reconstruction of silicon surfaces leads to a striking diversity of
outcomes. Despite this variety even very elaborate structures are generally
comprised of a small number of structural building blocks. We here identify
important elementary building blocks and discuss their integration into the
structural models as well as their impact on the electronic structure of the
surface
Antibacterial β-Glucan/Zinc Oxide Nanocomposite Films for Wound Healing
Advanced antimicrobial biomaterials for wound healing applications are an active field of research for their potential in addressing severe and infected wounds and overcoming the threat of antimicrobial resistance. Beta-glucans have been used in the preparation of these materials for their bioactive properties, but very little progress has been made so far in producing biomedical devices entirely made of beta-glucans and in their integration with effective antimicrobial agents. In this work, a simple and eco-friendly method is used to produce flexible beta-glucan/nanostructured zinc oxide films, using glucans derived from the yeast Saccharomyces cerevisiae. The properties of the films are characterized through scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, infrared and UV–visible spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and water absorption tests. Finally, the antibacterial properties of the nanostructured zinc oxide and of the composite films are assessed against Staphylococcus epidermidis and Escherichia coli, showing a marked effectiveness against the former. Overall, this study demonstrates how a novel bionanocomposite can be obtained towards the development of advanced wound healing devices
Supercritical solvent impregnation of different drugs in mesoporous nanostructured zno
Supercritical solvent impregnation (SSI) is a green unconventional technique for preparing amorphous drug formulations. A mesoporous nanostructured ZnO (mesoNsZnO) carrier with 8-nm pores, spherical-nanoparticle morphology, and an SSA of 75 m2/g has been synthesized and, for the first time, subjected to SSI with poorly water-soluble drugs. Ibuprofen (IBU), clotrimazole (CTZ), and hydrocortisone (HC) were selected as highly, moderately, and poorly CO2-soluble drugs. Powder X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, nitrogen adsorption analysis, and ethanol extraction coupled with ultraviolet spectroscopy were employed to characterize the samples and quantify drug loading. Successful results were obtained with IBU and CTZ while HC loading was negligible, which could be related to different solubilities in CO2, drug size, and polarity. Successful SSI resulted in amorphous multilayer confinement of the drug. The mesoNsZnO-IBU system showed double drug loading than the mesoNsZnO-CTZ one, with a maximum uptake of 0.24 g/g. Variation of contact time during SSI of the mesoNsZnO-IBU system showed that drug loading triplicated between 3 and 8 h with an additional 30% increment between 8 h and 24 h. SSI did not affect the mesoNsZnO structure, and the presence of the adsorbed drug reduced the chemisorption of CO2 on the carrier surface
Understanding Selectivity of Mesoporous Silica-Grafted Diglycolamide-Type Ligands in the Solid-Phase Extraction of Rare Earths
Rare earth elements (REEs) and their compounds are essential for rapidly developing modern technologies. These materials are especially critical in the area of green/sustainable energy; however, only very high-purity fractions are appropriate for these applications. Yet, achieving efficient REE separation and purification in an economically and environmentally effective way remains a challenge. Moreover, current extraction technologies often generate large amounts of undesirable wastes. In that perspective, the development of selective, reusable, and extremely efficient sorbents is needed. Among numerous ligands used in the liquid-liquid extraction (LLE) process, the diglycolamide-based (DGA) ligands play a leading role. Although these ligands display notable extraction performance in the liquid phase, their extractive chemistry is not widely studied when such ligands are tethered to a solid support. A detailed understanding of the relationship between chemical structure and function (i.e., extraction selectivity) at the molecular level is still missing although it is a key factor for the development of advanced sorbents with tailored selectivity. Herein, a series of functionalized mesoporous silica (KIT-6) solid phases were investigated as sorbents for the selective extraction of REEs. To better understand the extraction behavior of these sorbents, different spectroscopic techniques (solid-state NMR, X-ray photoelectron spectroscopy, XPS, and Fourier transform infrared spectroscopy, FT-IR) were implemented. The obtained spectroscopic results provide useful insights into the chemical environment and reactivity of the chelating ligand anchored on the KIT-6 support. Furthermore, it can be suggested that depending on the extracted metal and/or structure of the ligand and its attachment to KIT-6, different functional groups (i.e., C= O, N-H, or silanols) act as the main adsorption centers and preferentially capture targeted elements, which in turn may be associated with the different selectivity of the synthesized sorbents. Thus, by determining how metals interact with different supports, we aim to better understand the solid-phase extraction process of hybrid (organo)silica sorbents and design better extraction materials
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