349 research outputs found
Railway deformation detected by DInSAR over active sinkholes in the Ebro Valley evaporite karst, Spain
Subsidence was measured for the first time on railway tracks in the central sector of Ebro Valley (NE Spain) using Differential Synthetic Aperture Radar Interferometry (DInSAR) techniques. This area is affected by evaporite karst and the analysed railway corridors traverse active sinkholes that produce deformations in these infrastructures. One of the railway tracks affected by slight settlements is the Madrid-Barcelona high-speed line, a form of transport infrastructure highly vulnerable to ground deformation processes. Our analysis based on DInSAR measurements and geomorphological surveys indicates that this line shows dissolution-induced subsidence and compaction of anthropogenic deposits (infills and embankments). Significant sinkhole-related subsidence was also measured by DInSAR techniques on the CastejĂłn-Zaragoza conventional railway line. This study demonstrates that DInSAR velocity maps, coupled with detailed geomorphological surveys, may help in the identification of the railway track sections that are affected by active subsidence
Robustness of different indicators of quantumness in the presence of dissipation
The dynamics of a pair of coupled harmonic oscillators in separate or common
thermal environments is studied, focusing on different indicators of
quantumness, such as entanglement, twin oscillators correlations and quantum
discord. We compare their decay under the effect of dissipation and show,
through a phase diagram, that entanglement is more likely to survive
asymptotically than twin oscillators correlations
Comparison between Spanish and Italian Regulations on Cooperative Firms: Traditional or Hybrid Model?
This paper analyses the differences between the regulations on agrarian cooperatives set up in Spain and Italy. Some of these aspects are related to the solutions proposed and used by cooperatives belonging to the hybrid model to solve problems faced by the cooperatives belonging to the traditional model. The main differences
in the calculation of returns and reserves and in the fiscal aspects involved have also been analysed. Although in both countries there exist regulations referring to the hybrid model, the lack of conditions required for their implementation and the absence of professional management makes cooperatives of both countries fall within the traditional model. Several differences have been found in terms of the calculation of returns and reserves and of the fiscal aspects involved.Ce document analyse les différences entre la loi espagnole et la loi italienne sur les coopératives agricoles. Certaines différences relèvent aux solutions que les coopératives hybrides proposent et mettent en oeuvre afin de résoudre les problèmes auxquels les coopératives traditionnelles font face. Même les différences principales en ce qui concerne aussi bien le calcul de la rentabilité économique et des réserves que les aspects fiscaux impliqués ont été investiguées. En réalité, aussi bien les coopératives espagnoles que les coopératives italiennes appartiennent au modèle traditionnel, même si dans les deux pays il existe un règlement concernant des aspects du modèle hybride. L’ennui c’est qu’il y a le manque de conditions requises et de staff professionnel adéquat pour la mise sur pied du modèle hybride. Bon nombre de différences ont été trouvées en matière de calcul de la rentabilité économique et des réserves et des aspects fiscaux impliqués
Entanglement dynamics in presence of diversity under decohering environments
We study the evolution of entanglement of a pair of coupled, non-resonant
harmonic oscillators in contact with an environment. For both the cases of a
common bath and of two separate baths for each of the oscillators, a full
master equation is provided without rotating wave approximation. This allows us
to characterize the entanglement dynamics as a function of the diversity
between the oscillators frequencies and their mutual coupling. Also the
correlation between the occupation numbers is considered to explore the degree
of quantumness of the system. The singular effect of the resonance condition
(identical oscillators) and its relationship with the possibility of preserving
asymptotic entanglement are discussed. The importance of the bath's memory
properties is investigated by comparing Markovian and non-Markovian evolutions
Microscopic description for the emergence of collective dissipation in extended quantum systems
Practical implementations of quantum technology are limited by unavoidable effects of decoherence and dissipation. With achieved experimental control for individual atoms and photons, more complex platforms composed by several units can be assembled enabling distinctive forms of dissipation and decoherence, in independent heat baths or collectively into a common bath, with dramatic consequences for the preservation of quantum coherence. The cross-over between these two regimes has been widely attributed in the literature to the system units being farther apart than the bath's correlation length. Starting from a microscopic model of a structured environment (a crystal) sensed by two bosonic probes, here we show the failure of such conceptual relation, and identify the exact physical mechanism underlying this cross-over, displaying a sharp contrast between dephasing and dissipative baths. Depending on the frequency of the system and, crucially, on its orientation with respect to the crystal axes, collective dissipation becomes possible for very large distances between probes, opening new avenues to deal with decoherence in phononic baths
Dimensional Stability and Process Capability of an Industrial Component Injected with Recycled Polypropylene
The usage of recycled polymers for industrial purposes arises as one of the most promising methods of reducing environmental impact and costs associated with scrapping parts. This paper presents a systematic study of the dimensional stability of a raw and 100% recycled polypropylene subjected to realistic environmental conditions occurring along its working life. The component studied is an internal part of an induction hob assembly. Industrial samples manufactured with both materials, in the same mold, and in the same injection machine, are subjected to ejection conditions, storage conditions (50 °C), and extreme performance conditions (80 °C). Induced dimensional changes are registered and analyzed using a coordinate measuring machine, and a tactile sensing probe. To verify the process capability of the samples manufacturing, Cp and Cpk values are calculated to evaluate the suitability of the recycled material as an alternative. Results conclude that, although the use of recycled material implies slight differences in terms of dimensional stability due to the changes induced in the polymer structure, these differences are not significant enough to affect the injection process capability. Therefore, recycling arises as one effective method to reduce both overruns associated with the consumption of raw polypropylene material and its environmental impact
New insights into the genesis of the Miocene collapse structures of the island of Gozo (Malta, central Mediterranean Sea)
The large palaeosinkholes located in the NW of Gozo (central Mediterranean Sea, Malta) offer excellent exposures that provide information on the geometry and kinematics of large karst-related collapse structures. Detailed geological analysis of these peculiar palaeosinkholes indicates that deep-seated evaporite dissolution is the most feasible hypothesis to explain their formation, according to the following evidence. (1) Several structures have been formed by progressive foundering of cylindrical blocks with limited internal deformation as revealed by the synsedimentary subsidence recorded by their Miocene sedimentary fill. This subsidence mechanism is more compatible with interstratal dissolution of evaporites than karstification and cave development in limestone formations. (2) The dimensions and deformation style of the palaeosinkholes are similar to those of other collapse structures related to deep-seated dissolution of salt-bearing evaporites. (3) The arcuate monocline associated with some of these collapse structures is also a characteristic feature of subsidence related to dissolution of evaporites.
However, no major evaporite formations have been documented so far in the subsurface of the Malta Platform
Optimized Planar Penning Traps for Quantum Information Studies
A one-electron qubit would offer a new option for quantum information
science, including the possibility of extremely long coherence times.
One-quantum cyclotron transitions and spin flips have been observed for a
single electron in a cylindrical Penning trap. However, an electron suspended
in a planar Penning trap is a more promising building block for the array of
coupled qubits needed for quantum information studies. The optimized design
configurations identified here promise to make it possible to realize the
elusive goal of one trapped electron in a planar Penning trap for the first
time - a substantial step toward a one-electron qubit
Creation and manipulation of entanglement in spin chains far from equilibrium
We investigate creation, manipulation, and steering of entanglement in spin
chains from the viewpoint of quantum communication between distant parties. We
demonstrate how global parametric driving of the spin-spin coupling and/or
local time-dependent Zeeman fields produce a large amount of entanglement
between the first and the last spin of the chain. This occurs whenever the
driving frequency meets a resonance condition, identified as "entanglement
resonance". Our approach marks a promising step towards an efficient quantum
state transfer or teleportation in solid state system. Following the reasoning
of Zueco et al. [1], we propose generation and routing of multipartite
entangled states by use of symmetric tree-like structures of spin chains.
Furthermore, we study the effect of decoherence on the resulting spin
entanglement between the corresponding terminal spins.Comment: 10 pages, 8 figure
Sustained Gq-Protein Signaling Disrupts Striatal Circuits via JNK
International audienceThe dorsal striatum is a major input structure of the basal ganglia and plays a key role in the control of vital processes such as motor behavior, cognition, and motivation. The functionality of striatal neurons is tightly controlled by various metabotropic receptors. Whereas the G s /G i-protein-dependent tuning of striatal neurons is fairly well known, the precise impact and underlying mechanism of G q-protein-dependent signals remain poorly understood. Here, using different experimental approaches, especially designer receptor exclusively activated by designer drug (DREADD) chemogenetic technology, we found that sustained activation of G q-protein signaling impairs the functionality of striatal neurons and we unveil the precise molecular mechanism underlying this process: a phospholipase C/Ca 2Ď© /proline-rich tyrosine kinase 2/cJun N-terminal kinase pathway. Moreover, engagement of this intracellular signaling route was functionally active in the mouse dorsal striatum in vivo, as proven by the disruption of neuronal integrity and behavioral tasks. To analyze this effect anatomically, we manipulated G q-protein-dependent signaling selectively in neurons belonging to the direct or indirect striatal pathway. Acute G q-protein activation in direct-pathway or indirect-pathway neurons produced an enhancement or a decrease, respectively , of activity-dependent parameters. In contrast, sustained G q-protein activation impaired the functionality of direct-pathway and indirect-pathway neurons and disrupted the behavioral performance and electroencephalography-related activity tasks controlled by either anatomical framework. Collectively, these findings define the molecular mechanism and functional relevance of G q-protein-driven signals in striatal circuits under normal and overactivated states
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