4,321 research outputs found

    Microwave intermodulation distortion of MgB2 thin films

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    The two tone intermodulation arising in MgB2 thin films deposited in-situ by planar magnetron sputtering on sapphire substrates is studied. Samples are characterised using an open-ended dielectric puck resonator operating at 8.8 GHz. The experimental results show that the third order products increase with the two-tone input power with a slope ranging between 1.5 and 2.3. The behaviour can be understood introducing a mechanism of vortex penetration in grain boundaries as the most plausible source of non linearities in these films. This assumption is confirmed by the analysis of the field dependence of the surface resistance, that show a linear behaviour at all temperatures under test.Comment: 13 pages, 3 figures; to be published in Appl. Phys. Let

    Structure and morphology of an active conjugate relay zone, Messina Strait, southern Italy

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    Messina Strait is a narrow fault-bounded marine basin that separates the Calabrian peninsula from Sicily in southern Italy. It sits in a seismically active region where normal fault scarps and raised Quaternary marine terraces record ongoing extension driven by southeastward rollback of the Calabrian subduction zone. A review of published studies and new data shows that normal faults in the Messina Strait region define a conjugate relay zone where displacement is transferred along strike from NW-dipping normal faults in the northeast (southern Calabria) to the SE-dipping Messina-Taormina normal fault in the southwest (offshore eastern Sicily). The narrow marine strait is a graben undergoing active subsidence within the relay zone, where pronounced curvature of normal faults results from large strain gradients and clockwise rotations related to fault interactions. Based on regional fault geometries and published age constraints, we infer that normal faults in southern Calabria migrated northwest while normal faults in NE Sicily migrated southeast during the past ca. 2–2.5 Myr. This pattern has resulted in tectonic narrowing of the strait through time by inward migration of facing normal faults and rapid mantle-driven uplift

    The Perioperative Nursing Workforce Program in NSW: How a professional perioperative nursing association meets one of its mandates Part 1

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    The need to review and change the way nursing care is delivered in perioperative settings is predicated on nursing workforce shortages, the changing, increasingly technologised and risk-prone OR practice milieu, and increasing demand for surgery. In responding to members' concerns about these issues, the NSW Operating Theatre Association Inc. (NSW OTA) in conjunction with and with sponsorship from the NSW Chief Nursing and Midwifery Officer, initiated and oversaw the development of a program, called the Perioperative Nursing Workforce Program (PNWP). The aims of this program are to make better use of human resources, to improve the way care is provided and thus improve patient outcomes; and to empower perioperative nurses so they are capable of independently improving their working environment. The program, which takes a practice development approach, program participants and some of their projects are presented in this paper. What is known about the topic The role of perioperative professional nursing associations is to write standards for practice and to assist in the professional development of their members. Practice development is hypothesised to assist clinical nurses to 'see' their work contexts afresh and to implement changes to improve patient care by focusing on patient-centredness and the use of credible evidence. What this article contributes It describes the contents and the implementation of a perioperative nursing workforce program, initiated by the NSW OTA and auspiced by the Chief Nursing and Midwifery Officer, NSW Health. The PNWP uses the tenets of practice development (PD) to achieve its aims and this is possibly the first use of PD in perioperative settings, and on a statewide basis

    Quantum Field Theory of Forward Rates with Stochastic Volatility

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    In a recent formulation of a quantum field theory of forward rates, the volatility of the forward rates was taken to be deterministic. The field theory of the forward rates is generalized to the case of stochastic volatility. Two cases are analyzed, firstly when volatility is taken to be a function of the forward rates, and secondly when volatility is taken to be an independent quantum field. Since volatiltiy is a positive valued quantum field, the full theory turns out to be an interacting nonlinear quantum field theory in two dimensions. The state space and Hamiltonian for the interacting theory are obtained, and shown to have a nontrivial structure due to the manifold moving with a constant velocity. The no arbitrage condition is reformulated in terms of the Hamiltonian of the system, and then exactly solved for the nonlinear interacting case.Comment: 7 Figure

    Permeability characterisation of sedimentological facies in the Bunter Sandstone Formation, Endurance CO2 storage site, offshore UK

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    Permeability variations due to sedimentological heterogeneity are important in controlling CO2 migration pathways, CO2 plume dynamics, and stratigraphic, capillary and dissolution trapping of CO2 in subsurface storage units and complexes. Thus, knowing these parameters is crucial to developing a CO2 injection strategy that maximizes storage and trapping efficiency. In this study we analyzed the sedimentological and permeability heterogeneity of the Bunter Sandstone Formation at the Endurance CO2 storage site, offshore UK, through integrated facies analysis, minipermeameter measurements, and thin section analysis. Detailed core logging and outcrop analysis were performed to identify facies and related heterogeneities. Twelve lithofacies have been identified in cores. By analyzing the stacking patterns of the facies, three facies associations and three architectural elements were identified in cores and outcrop analogues, respectively. Heterogeneities occur at all the scales ranging from mm-scale laminae to 10′s m-scale architectural elements.Permeability variations at outcrop and in core are closely related to sedimentological heterogeneities. Minipermeameter and core plug permeability data show up to three orders of magnitude variation across the facies. Cross-bedded (Sp, St, Sl, Spmc) and structureless (Sm) sandstones are the most permeable (4–5400 mD) facies, whereas pebbly conglomerates (Gmg) and laminated mudstones (Fl) are least permeable (0.18–89 mD) facies. Mottled and deformed sandstone (Smd) and crinkly laminated sandstone (Sc) have highly variable permeability (0.69–480 mD). Minipermeameter data reveal permeability varies by a factor of five at centimeter scale within planar cross-bedded (Sp), trough cross-bedded (St) and planar bedded sandstone (Sh) sandstone facies, while planar cross-bedded sandstone with mud clasts along foresets (Spmc) exhibit permeability variation up to a factor of four. Petrographic analysis of thin sections shows that these permeability variations are related to changes in grain size, clay content, and distribution of dolomite cements

    The ATLAS discovery potential for MSSM neutral Higgs bosons decaying to a mu+mu- pair in the mass range up to 130 GeV

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    Results are presented on the discovery potential for MSSM neutral Higgs bosons in the Mh-{max}scenario. The region of large tan beta, between 15 and 50, and mass between ~ 95 and 130 GeV is considered in the framework of the ATLAS experiment at the Large Hadron Collider (LHC), for a centre-of-mass energy = 14 TeV. This parameter region is not fully covered by the present data either from LEP or from Tevatron. The h/A bosons, supposed to be very close in mass in that region, are studied in the channel h/A -> mu+mu- accompanied by two b-jets. The study includes a method to control the most copious background, Zo -> mu+mu- accompanied by two b-jets. A possible contribution of the H boson to the signal is also considered

    The adaptiveness in stock markets: testing the stylized facts in the DAX 30

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    © 2017, Springer-Verlag Berlin Heidelberg. By testing a simple asset pricing model of heterogeneous agents to characterize the power-law behavior of the DAX 30 from 1975 to 2007, we provide supporting evidence on empirical findings that investors and fund managers use combinations of fixed and switching strategies based on fundamental and technical analysis when making investment decisions. A mechanism analysis based on the calibrated model provides a behavioral insight into the explanatory power of rational switching behavior of investors on the volatility clustering and long range dependence in return volatility

    Wet Chemical Method for Making Graphene-like Films from Carbon Black

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    Reduction of strongly oxidized carbon black by hydrazine hydrate yields water-insoluble graphene-like sheets that undergo to self-assembling in thin film on surfaces after drying. The height of a drop-casted graphene-like film was determined by atomic force microscopy (AFM) to be around 20 nm, corresponding to approximately 25 graphene-like layers. The oxidized carbon black and the corresponding reduced form were carefully characterized

    Interplay of tidal and fluvial processes in an early Pleistocene, delta-fed, strait margin (Calabria, Southern Italy)

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    The architecture and morphodynamics of modern and ancient tidal straits and in particular the deposits of strait-margin zones, have been significantly understudied compared to other marginal marine settings, even though many reservoirs in the North Sea and the Norwegian Continental Shelf are developed in narrow grabens or seaways. This paper presents a detailed sedimentological and stratigraphic analysis of an early Pleistocene marginal-marine succession deposited along the northern margin of the Siderno paleostrait (southern Italy). This area represents an excellent case study of sedimentation along a tidal strait margin, interpreted to record the interaction of fluvial and tidal processes. Here, syn-depositional tectonics produced a complex coastal morphology, significantly influencing sedimentation and hydrodynamic processes. Along the strait margin, the emplacement of an isolated tectonic high (Piano Fossati) created a ca. 3.5 km-wide local passageway. This morpho-structural element induced interplays between fluvio-deltaic processes (fed from the northern strait margin) and tidal current reworking (active within the marine strait).The field-based facies analysis reported here documents an initial stage of non-tidal shallow-marine sedimentation across the strait. A subsequent regression caused river-generated hyperpycnal flows and the transfer of large volumes of pebbly and shelly sandstones into deeper water. Tidal currents became amplified in the strait, and, in the delta-front area, they were able to rework river-derived sediments generating large dune fields. Following the local tidal transport pathway, strong tidal currents skewed the delta front (causing it to be asymmetrical) and elongated sand bodies in a direction parallel to the marine strait axis. Differently from the classical tide-influenced deltas in which onshore-offshore tidal flow predominates, coast-parallel deflection and strong asymmetry of delta-front deposits is a typical feature of deltas entering tide-dominated seaways and straits, where strong tidal currents are capable of dispersing large volumes of sand for significant distances along the coast and along the strait axis. This process became progressively enhanced during the following transgression, when tide-modulated currents reworked biocalcarenitic sands over the previous delta deposits, generating southeasterly migrating dunes. At the end of the transgression, strandplain deposits formed in this area. This last stage of sedimentation was followed by a dramatic regional-scale structural uplift, which ended any marine circulation within the strait. This work provides new insights on sedimentation in a tide-dominated strait, and helps to predict sandbody distribution along the strait margin and axis. These findings can be applied to any other setting characterized by a narrow (possibly structurally-confined) basin dominated by tidal currents
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