2,201 research outputs found

    Jobs and Competitiveness in a Polarised Europe

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    In the aftermath of the crisis, Europe is becoming more polarised in terms of employment, competitiveness and industrial specialisation. A “German-centred core”–which maintained employment and production–has emerged, contrasted by a “Southern periphery”, where major economic losses have occurred. Such geographical divergence is associated with a further polarisation in terms of skills. A new European industrial policy is needed to reverse this polarisation process and its dangerous implications for trade balances and cohesion

    Superconducting nanowire quantum interference device based on Nb ultrathin films deposited on self-assembled porous Si templates

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    Magnetoresistance oscillations were observed on networks of superconducting ultrathin Nb nanowires presenting evidences of either thermal or quantum activated phase slips. The magnetic transport data, discussed in the framework of different scenarios, reveal that the system behaves coherently in the temperature range where the contribution of the fluctuations is important.Comment: accepted for publication on Nanotechnolog

    Technology and occupations in business cycles

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    Building on studies on the impact of the Great Recession on the occupational and skill structure of employment, this article investigates developments over the last business cycle (2002–2007 and 2007–2011) in 36 manufacturing and service industries of five major European countries (Germany, France, Spain, Italy and United Kingdom). We analyse how technology, education and wages have shaped the evolution of four professional groups—Managers, Clerks, Craft and Manual workers—defined on the basis of ISCO classes. During the upswing in manufacturing industries all professional groups except managers have experienced job losses, while new jobs in services have followed a pattern of growing occupational polarization. Demand growth has a general positive effect across all occupations; new products lead to job creation in the group of managers only; wage increases slow down job creation except in the lowest occupational group. During the downswing, large job losses are concentrated in the lowest occupations and most relationships—including the role of demand and wages—break down; product innovation loses its positive impact on jobs while new processes drive restructuring and job destruction across all professional groups

    Resting EEG asymmetry markers of multiple facets of the behavioral approach system: a LORETA analysis

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    Previously published models of frontal activity linked high relative left frontal activity to the behavioral approach system (BAS) and impulsivity. Additionally, these models did not account for BAS facets encompassing the anticipation of reward, i.e., goal-driven persistence (BAS–GDP) and reward interest (BAS–RI), from those that deal with the actual hedonic experience of reward, i.e., reward reactivity (BAS–RR) and impulsivity (BAS–I). Using resting electroencephalographic (EEG) recordings, the source localization (LORETA) method allowed us to calculate the hemispheric asymmetry of the current density within the alpha band (7.5–13 Hz) in ten regions of interest. Compared to low BAS subtrait scorers, high BAS subtrait scorers (except for BAS–I) were correlated with greater relative left-sided activity in the superior frontal gyrus (BA10). Further, an isolated effective coherence (iCOH) analysis of the beta activity (21 Hz) disclosed that high impulsive scorers as compared to low impulsive ones had higher connectivity between the superior frontal gyrus and middle temporal gyrus, which was not compensated for by enhanced inhibitory alpha (11 Hz) connectivity between these regions. For the beta frequency, we also found in highly impulsive individuals that (i) both left and right middle temporal lobes directly influenced the activity of the left and right superior frontal lobes, and (ii) a clear decoupling between left and right superior frontal lobes. These findings could indicate reduced control by the supervisory system in more impulsive individuals

    Microwave-induced flow of vortices in long Josephson junctions

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    We report experimental and numerical study of microwave-induced flow of vortices in long Josephson junctions at zero dc magnetic field. Our intriguing observation is that applying an ac-bias of a small frequency ffpf \ll f_p and sufficiently large amplitude changes the current-voltage characteristics (II-VV curve) of the junction in a way similar to the effect of dc magnetic field, well known as the flux-flow behavior. The characteristic voltage VV of this low voltage branch increases with the power PP of microwave radiation as VsPαV_{s}\propto P^{\alpha} with the index α0.5\alpha \simeq 0.5 . Experiments using a low-temperature laser scanning microscope unambiguously indicate the motion of Josephson vortices driven by microwaves. Numerical simulations agree with the experimental data and show strongly {\it irregular} vortex motion. We explain our results by exploiting an analogy between the microwave-induced vortex flow in long Josephson junctions and incoherent multi-photon absorption in small Josephson junctions in the presence of large thermal fluctuations. In the case of long Josephson junctions the spatially-temporal chaos in the vortex motion mimics the thermal fluctuations. In accordance with this analogy, a control of the intensity of chaos in a long junction by changing its damping constant leads to a pronounced change in the shape of the II-VV curve. Our results provide a possible explanation to previously measured but not yet understood microwave-driven properties of intrinsic Josephson junctions in high-temperature superconductors.Comment: 8 pages, 13 figure

    Hybrid Superconducting Neutron Detectors

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    A new neutron detection concept is presented that is based on superconductive niobium (Nb) strips coated by a boron (B) layer. The working principle of the detector relies on the nuclear reaction 10B+n \rightarrow α\alpha+ 7Li , with α\alpha and Li ions generating a hot spot on the current-biased Nb strip which in turn induces a superconducting-normal state transition. The latter is recognized as a voltage signal which is the evidence of the incident neutron. The above described detection principle has been experimentally assessed and verified by irradiating the samples with a pulsed neutron beam at the ISIS spallation neutron source (UK). It is found that the boron coated superconducting strips, kept at a temperature T = 8 K and current-biased below the critical current Ic, are driven into the normal state upon thermal neutron irradiation. As a result of the transition, voltage pulses in excess of 40 mV are measured while the bias current can be properly modulated to bring the strip back to the superconducting state, thus resetting the detector. Measurements on the counting rate of the device are presented and the future perspectives leading to neutron detectors with unprecedented spatial resolutions and efficiency are highlighted.Comment: 8 pages 6 figure

    Integrating Superconductive and Optical Circuits

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    We have integrated on oxidized silicon wafers superconductive films and Josephson junctions along with sol-gel optical channel waveguides. The fabrication process is carried out in two steps that result to be solid and non-invasive. It is demonstrated that 660 nm light, coupled from an optical fibre into the channel sol-gel waveguide, can be directed toward superconducting tunnel junctions whose current-voltage characteristics are affected by the presence of the radiation. The dependence of the change in the superconducting energy gap under optical pumping is discussed in terms of a non-equilibrium superconductivity model.Comment: Document composed of 7 pages of text and 3 figure

    Right phrenic nerve palsy following transcatheter radiofrequency current atrial fibrillation ablation: Case report

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    Phrenic nerve palsy (PNP) is a well-known complication of cardiac surgery or jugular/subclavian vein catheterization, presenting with cough, hiccups, dyspnoea/shortness of breath and, in some cases, ventilatory failure. Rarely, PNP is a complication of transcatheter radiofrequency ablation for atrial fibrillation. This report describes the case of a 72-year-old woman with a 2-year history of recurrent paroxysmal atrial fibrillation associated with occasional palpitations and shortness of breath who underwent routine transcatheter radiofrequency ablation. Three days after the procedure, the patient developed shortness of breath and progressive dyspnoea. Motor nerve conduction showed the absence of the right phrenic nerve compound motor action potential compared with the normal left side confirming the diagnosis of a right phrenic nerve palsy. This current case demonstrated the importance of undertaking an electrophysiological evaluation of phrenic nerve conduction after transcatheter radiofrequency ablation in patients presenting with palpitations and shortness of breath even if present a few days after the procedure

    Quantum phase slips in superconducting Nb nanowire networks deposited on self-assembled Si templates

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    Robust porous silicon substrates were employed for generating interconnected networks of superconducting ultrathin Nb nanowires. Scanning electron microscopy analysis was performed to investigate the morphology of the samples, which constitute of polycrystalline single wires with grain size of about 10 nm. The samples exhibit nonzero resistance over a broad temperature range below the critical temperature, fingerprint of phase slippage processes. The transport data are satisfactory reproduced by models describing both thermal and quantum fluctuations of the superconducting order parameter in thin homogeneous superconducting wires.Comment: accepted for publication on Applied Physics Letter
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