Alluvial gravel sedimentation in a contractional growth fold setting, Sant Llorenc de Morunys, southeastern Pyrenees

This paper is included in the Special Publication entitled 'Cenozoic foreland basins of Western Europe' edited by A. Mascle, C. Puigdefabregas, H.P. Luterbacher and M. Fernandez. New data are presented on the classic growth structure at Sant Llorenc de Morunys (NE Ebro Basin, Spain). During the late Eocene to Oligocene thick alluvial-fan gravel sediments accumulated principally by repetitive sub-aerial mass flow (cohesionless debris flow and fluidal sediment flow) events, with smaller volumes of fan-stream flows. Subaerial, high-viscosity (cohesive) debris flows contributed comparatively small volumes of sediment to the succession. These sediments constructed a complex architecture of conglomeratic and sandstone-bearing lithosomes that were affected by stratal thickening and erosion across a growth fold pair and genetically related internal unconformities, which formed a long-lived thrust-related structure in the immediate footwall of the SE Pyrenean mountain front. Four periods of evolution for the Sant Llorenc growth structure are defined on the basis of distintive stratigraphical architecture. These describe a gross evolution from onlapping to overlapping growth strata, related to the ultimate demise of growth folding. In detail complex erosional and offlapping events punctuated the growth history, which shows extreme variation parallel to the axis of the structure. Patterns of palaeoflow were highly complex, showing distinct axial and transverse directions relatable to growth fold evolutionary periods. Palaeocurrents are considered to have been deflected and diverted by surficial differential subsidence and areas of relative uplift and erosion generated by fold growth. The complexity of sediment dispersal is compounded by variables intrinsic to alluvial fan environments. The Sant Llorenc de Morunys growth strata provide information on how sediments are reorganized by syndepositionally-growing structures and on the nature of sediment distribution between external fold-and-thrust belts and foreland basins

Methodology and reliability of respiratory muscle assessment

The optimal method for respiratory muscle endurance (RME) assessment remains unclear. This study assessed the test-retest reliability of two RME-test methodologies. Fifteen healthy adults attended the laboratory on four occasions, separated by 5 ± 2 days, and completed each test in a random, “one on two” order. They performed spirometry testing, maximal respiratory pressure assessment and two different RME tests: an inspiratory resistive breathing (IRB) and an isocapnic hyperpnea endurance (IHE) test. Typical error, expressed as coefficient of variation, for IRB maximal inspiratory pressure (MIP) and IHE maximal ventilation were 12.21 (8.85–19.67) % and 10.73 (7.78–17.29) %, respectively. Intraclass correlation coefficients for the same parameters were 0.83 (0.46-0.94) and 0.80 (0.41-0.93), respectively. No correlations were found between RME parameters derived from the IHE and IRB tests (all p > 0.05). Significant positive correlations were found between both IRB and IHE outcomes and spirometry parameters, MIP and maximal expiratory pressure (p < 0.05).Given these results, IRB and IHE appear to be suitable for RME testing in healthy people, although they may reflect different physiological mechanisms (respiratory mechanics and respiratory muscle capacity for IHE test vs. inspiratory muscle capacity for IRB test). Future studies are therefore warranted that compare IRB and IHE tests in clinical settings

Superconductivity of a Metallic Stripe Embedded in an Antiferromagnet

We study a simple model for the metallic stripes found in $La_{1.6-x}Nd_{0.4}Sr_xCuO_4$: two chain Hubbard ladder embedded in a static antiferromagnetic environments. We consider two cases: a ``topological stripe'', for which the phase of the Neel order parameter shifts by $\pi$ across the ladder, and a ``non-topological stripe'', for which there is no phase shift across the ladder. We perform one-loop renormalization group calculations to determine the low energy properties. We compare the results with those of the isolated ladder and show that for small doping superconductivity is enhanced in the topological stripe, and suppressed in the non-topological one. In the topological stripe, the superconducting order parameter is a mixture of a spin singlet component with zero momentum and a spin triplet component with momentum $\pi$. We argue that this mixture is generic, and is due to the presence of a new term in the quantum Ginzburg-Landau action. Some consequences of this mixing are discussed.Comment: 6 pages, 3 eps figure

Implications of Charge Ordering for Single-Particle Properties of High-Tc Superconductors

The consequences of disordered charge stripes and antiphase spin domains for the properties of the high-temperature superconductors are studied. We focus on angle-resolved photoemission spectroscopy and optical conductivity, and show that the many unusual features of the experimentally observed spectra can be understood naturally in this way. This interpretation of the data, when combined with evidence from neutron scattering and NMR, suggests that disordered and fluctuating stripe phases are a common feature of high-temperature superconductors.Comment: 4 pages, figures by fax or mai

Fault-controlled and stratabound dolostones in the Late Aptian-earliest Albian Benassal Formation (Maestrat Basin, E Spain) : petrology and geochemistry constrains

This study was developed under the ExxonMobil FC2 Alliance (Fundamental Controls on Flow in Carbonates). The authors wish to thank ExxonMobil Production Company and ExxonMobil Upstream Research Company for providing funding. The views in this article by Sherry L. Stafford are her own and not necessarily those of ExxonMobil. This research was supported by the Sedimentary Geology Research Group of the Generalitat de Catalunya (2014SGR251). We would like to thank Andrea Ceriani and Paola Ronchi for their critical and valuable reviews, and Associated Editor Piero Gianolla for the editorial work.Peer reviewedPostprin

Structural Disorder Induced Polaron Formation and Magnetic Scattering in the Disordered Holstein-Double Exchange Model

In this paper we present results on the disordered Holstein-Double Exchange model, explicitly in three dimension and `metallic' densities, obtained by using a recently developed Monte Carlo approach. Following up on our earlier paper, cond-mat/0406085, here we provide a detailed microscopic picture of the thermally driven metal-insulator transition (MIT) that arises close to the ferromagnet to paramagnet transition in this problem. This paper is focused mainly on the `diagnostics', clarifying the origin of the effective disorder that drives the MIT in this system. To that effect, we provide results on the thermal evolution of the distributions of (i) lattice distortions, (ii) the net `structural disorder' and (iii) the `hopping disorder' arising from spin randomness feeding back through the Hunds coupling. We suggest a phenomenology for the thermally driven MIT, viewing it as an `Anderson-Holstein' transition.Comment: 6 pages, latex, JPSJ style, 7 eps figs. Style files included. Proceedings of the SPQS Meeting at Sendai, Japan, 2004. To appear in JPS

Signatures of Stripe Phases in Hole Doped La2NiO4La_2NiO_4

We study nickelate-centered and oxygen-centered stripe phases in doped La$_{2}$NiO$_{4}$ materials. We use an inhomogeneous Hartree-Fock and random-phase approximation approach including both electron-electron and electron-lattice(e-l) coupling for a layer of La$_{2}$NiO$_{4}$. We find that whether the ground state after commensurate hole doping comprises Ni-centered or O-centered charge-localized stripes depends sensitively on the e-l interaction. With increasing e-l interaction strength, a continuous transition from an O-centered stripe phase to a Ni-centered one is found. Various low- and high-energy signatures of these two kinds of stripe phases are predicted, which can clearly distinguish them. These signatures reflect the strongly correlated spin-charge-lattice features in the vicinity of Ni-centered or O-centered stripe domains. The importance of e-l interaction for recent experiments on stripe phases is discussed.Comment: 11 pages, 12 figures, to appear in Phys.Rev.B(July 1,1998

Optimal trapping wavelengths of Cs2_2 molecules in an optical lattice

The present paper aims at finding optimal parameters for trapping of Cs$_2$ molecules in optical lattices, with the perspective of creating a quantum degenerate gas of ground-state molecules. We have calculated dynamic polarizabilities of Cs$_2$ molecules subject to an oscillating electric field, using accurate potential curves and electronic transition dipole moments. We show that for some particular wavelengths of the optical lattice, called "magic wavelengths", the polarizability of the ground-state molecules is equal to the one of a Feshbach molecule. As the creation of the sample of ground-state molecules relies on an adiabatic population transfer from weakly-bound molecules created on a Feshbach resonance, such a coincidence ensures that both the initial and final states are favorably trapped by the lattice light, allowing optimized transfer in agreement with the experimental observation