Coherent caloritronics in Josephson-based nanocircuits

We describe here the first experimental realization of a heat interferometer, thermal counterpart of the well-known superconducting quantum interference device (SQUID). These findings demonstrate, on the first place, the existence of phase-dependent heat transport in Josephson-based superconducting circuits and, on the second place, open the way to novel ways of mastering heat at the nanoscale. Combining the use of external magnetic fields for phase biasing and different Josephson junction architectures we show here that a number of heat interference patterns can be obtained. The experimental realization of these architectures, besides being relevant from a fundamental physics point of view, might find important technological application as building blocks of phase-coherent quantum thermal circuits. In particular, the performance of two different heat rectifying devices is analyzed.Comment: 34 pages, 15 figures, review article for Ultra-low temperatures and nanophysics ULTN2013. Microkelvin Proceeding

Nongalvanic thermometry for ultracold two-dimensional electron domains

Measuring the temperature of a two-dimensional electron gas at temperatures of a few mK is a challenging issue, which standard thermometry schemes may fail to tackle. We propose and analyze a nongalvanic thermometer, based on a quantum point contact and quantum dot, which delivers virtually no power to the electron system to be measured.Comment: 5 pages, 3 figure

Performance Of The High Speed Rail In Spain In The Context Of The New Regulation Framework. Evidence From The Madrid-Seville Hsr Corridor

The ambitious planned development of the high-speed rail (HSR) network in Spain requires the implementation of new sector regulations to fully achieve its objectives, namely to make the sector more competitive and to promote a more balanced and efficient transport system. For this purpose, the Spanish administration recently launched the new Rail Sector Act (39/2003), on a national regulatory framework. The planned liberalisation process foresees the end of the monopoly of the Spanish state operator RENFE, opening up passenger transport to new rail operators by 2010. On a European level, this new regulatory framework comes in line with EU’s concerns both on transport service performance and on infrastructure development. On the one hand, European regulations have focused in measures to guarantee quality of service, equal access and effective competition market rules. On the other, the relevance of the development of HSR projects in the Iberian peninsula is proved with their inclusion among the priority projects of the trans-European networks (TEN).Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Trees, homology, and automorphism groups of right-angled Artin groups

We study the homology of an explicit finite-index subgroup of the automorphism group of a partially commutative group, in the case when its defining graph is a tree. More concretely, we give a lower bound on the first Betti number of this subgroup, based on the number and degree of a certain type of vertices, which we call deep. We then use combinatorial methods to analyze the average value of this Betti number, in terms of the size of the defining tree

Point defects on graphene on metals

Understanding the coupling of graphene with its local environment is critical to be able to integrate it in tomorrow's electronic devices. Here we show how the presence of a metallic substrate affects the properties of an atomically tailored graphene layer. We have deliberately introduced single carbon vacancies on a graphene monolayer grown on a Pt(111) surface and investigated its impact in the electronic, structural and magnetic properties of the graphene layer. Our low temperature scanning tunneling microscopy studies, complemented by density functional theory, show the existence of a broad electronic resonance above the Fermi energy associated with the vacancies. Vacancy sites become reactive leading to an increase of the coupling between the graphene layer and the metal substrate at these points; this gives rise to a rapid decay of the localized state and the quenching of the magnetic moment associated with carbon vacancies in free-standing graphene layers

Self-organization of ultrasound in viscous fluids

We report the theoretical and experimental demonstration of pattern formation in acoustics. The system is an acoustic resonator containing a viscous fluid. When the system is driven by an external periodic force, the ultrasonic field inside the cavity experiences different pattern-forming instabilities leading to the emergence of periodic structures. The system is also shown to possess bistable regimes, in which localized states of the ultrasonic field develop. The thermal nonlinearity in the viscous fluid, together with the far-from-equilibrium conditions, are is the responsible of the observed effects

Metropolitan Mobility In Spain Are We Tending Towards Sustainability?

There is a growing concern in the urban transport field about the development of a data set of indicators that would allow to undertake ongoing monitoring and evaluation of current transportation policies, compare data from territories facing the same kind of challenges, identify good practices and strategies to be followed, and strengthen the information, participation and decision-making process. These data set of indicators, known as observatories, are aimed to fulfil stakeholders needs, so that they achieve the precise knowledge to adopt pertinent policies. The Spanish Metropolitan Mobility Observatory, sponsored by the Spanish Ministry of Environment, was launched in 2003 by the Metropolitan Transport Authorities of the major metropolitan areas in Spain, and TRANSyT. Its scope is to identify those elements within urban transport policy packages which have had a more significant impact on mobility (i.e. global transport demand, travel time, modal split,…), and on land use patterns. And its main goal is to serve as basis for Metropolitan Transport Authorities to improve operation of their public transport system, and thus increasing their contribution to sustainable mobility. For itsFor its second edition, based on the year 2003, a set of data from the different Metropolitan Transport Authorities has been collected, in order to: Highlight public transport contribution to improve urban areas and sustainable development - Describe the role of Metropolitan Transport Authorities in achieving an attractive and quality public transport - Monitoring transport supply and demand characteristics, focusing on public transport - Analyse resources dedicated to the public transport system - Describe the financial models used for the public transport system - Highlight the main initiatives and innovations developed by Metropolitan areas This information will be compared to that one from the previous edition, and a statistical analysis will be conducted in order to identify those variables, which are likely to explainresults in most cities.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Metropolitan Mobility In Spain Are We Tending Towards Sustainability?

Workshop FThere is a growing concern in the urban transport field about the development of a data set of indicators that would allow to undertake ongoing monitoring and evaluation of current transportation policies, compare data from territories facing the same kind of challenges, identify good practices and strategies to be followed, and strengthen the information, participation and decision-making process. These data set of indicators, known as observatories, are aimed to fulfil stakeholders needs, so that they achieve the precise knowledge to adopt pertinent policies. The Spanish Metropolitan Mobility Observatory, sponsored by the Spanish Ministry of Environment, was launched in 2003 by the Metropolitan Transport Authorities of the major metropolitan areas in Spain, and TRANSyT. Its scope is to identify those elements within urban transport policy packages which have had a more significant impact on mobility (i.e. global transport demand, travel time, modal split,…), and on land use patterns. And its main goal is to serve as basis for Metropolitan Transport Authorities to improve operation of their public transport system, and thus increasing their contribution to sustainable mobility. For itsFor its second edition, based on the year 2003, a set of data from the different Metropolitan Transport Authorities has been collected, in order to: Highlight public transport contribution to improve urban areas and sustainable development - Describe the role of Metropolitan Transport Authorities in achieving an attractive and quality public transport - Monitoring transport supply and demand characteristics, focusing on public transport - Analyse resources dedicated to the public transport system - Describe the financial models used for the public transport system - Highlight the main initiatives and innovations developed by Metropolitan areas This information will be compared to that one from the previous edition, and a statistical analysis will be conducted in order to identify those variables, which are likely to explainresults in most cities.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Y-stent-assisted coil embolization of anterior circulation aneurysms using two solitaire AB devices: a single enter experience

Wide-neck intracranial aneurysms remain a challenge to endovascular treatment. We describe our experience in repairing wide-neck aneurysms of the anterior circulation located at arterial branch points using coil embolization assisted by Y-stenting using two Solitaire® stents. Six wide-neck intracranial aneurysms located on the middle cerebral artery bifurcation 3, pericallosal artery 1, and anterior communicating artery 2 were repaired by Y-stent-assisted coil embolization using two Solitaire® stents. Four cases were incidental findings of aneurysm and two cases were previously treated ruptured aneurysms that had undergone recanalization. All the cases were successfully treated without complications. Follow-up by digital subtraction angiography and magnetic resonance angiography at six months showed the stents to be patent with no recanalization of the aneurysm sacs. Repairing wide-neck aneurysms of the anterior circulation by Y-stent-assisted coil embolization using two Solitaire® stents is a simple and safe method of treating complex aneurysms. While the results are promising, larger series with longer term follow-ups are needed to corroborate that this treatment method is superior to other technique

Endmember extraction algorithms from hyperspectral images

During the last years, several high-resolution sensors have been developed for hyperspectral remote sensing applications. Some of these sensors are already available on space-borne devices. Space-borne sensors are currently acquiring a continual stream of hyperspectral data, and new efficient unsupervised algorithms are required to analyze the great amount of data produced by these instruments. The identification of image endmembers is a crucial task in hyperspectral data exploitation. Once the individual endmembers have been identified, several methods can be used to map their spatial distribution, associations and abundances. This paper reviews the Pixel Purity Index (PPI), N-FINDR and Automatic Morphological Endmember Extraction (AMEE) algorithms developed to accomplish the task of finding appropriate image endmembers by applying them to real hyperspectral data. In order to compare the performance of these methods a metric based on the Root Mean Square Error (RMSE) between the estimated and reference abundance maps is used