Quantum Interference Phenomena Between Impurity States in d-wave Superconductors

We investigate the mutual influence of impurities in two-dimensional d-wave superconductors involving self-consistent solutions of the Bogoliubov-de Gennes equations. The local order parameter suppression, the local density of states (LDOS) as well as the interference of impurity-induced structures are analyzed. We employ an impurity position averaging scheme for the DOS that does not neglect these interference effects, as the commonly used $T$-matrix approaches do.Comment: 4 eps figures, presented at SNS200

Pollutant emissions in common-rail diesel engines in extraurban cycle: rapeseed oils vs diesel fuel

The new energy strategy of EU (i.e., Directive 2009/28/EC) requires increasing the use of biofuels in transports up to at least 10% of the total fuel consumption. In the last years, the share of Diesel engines in automotive applications reached about 55% in EU market, thus trying to widen the alternatives to Diesel fuel is very important. In this framework straight vegetable oils (SVO) can represent one of the available possibilities at least in some specific applications (i.e., public transportation, hybrid or marine propulsion, etc.). SVO properties may be very different form Diesel fuel, thus operating a Diesel engine with SVO might result in some problems, especially in automotive configuration where the electronic unit acts as if it is working with Diesel fuel. This reflects in possible engine power and torque reduction, maintenance problems, and pollutant emissions during vehicles running. The latter aspect is the focus of the present paper. In this work, we used a turbocharged, four stroke, four cylinders, water cooled, commonrail multijet Diesel engine in automotive configuration to simulate the extraurban cycle according to the EU standard, comparing pollutant emissions in case of SVO and gasoil fuelling

Toolkit for simulated commissioning of storage-ring light sources and application to the advanced light source upgrade accumulator

We present a new accelerator toolbox (AT)-based toolkit for simulating the commissioning of light-source storage rings. The toolkit provides a framework for supporting high-level scripts to represent with realism the various procedures (e.g., orbit and optics correction, beam-based alignment, etc.) encountered during commissioning and is designed to mirror as closely as possible the reality as seen from the control room. Emphasis is placed on the inclusion of a comprehensive set of error sources and faithful modeling of beam diagnostics. The toolkit capabilities are demonstrated in an application to the recent design and commissioning studies of the Advanced Light Source Upgrade (ALS-U) Accumulator Ring, a short-time successful commissioning of which will be critical to the overall ALS-U project success

Reply to Comment on:"Nonmonotonic d_{x^2-y^2} Superconducting Order Parameter in Nd_{2-x}Ce_xCuO_4"

We confirm that all the results of scanning SQUID, tunneling, ARPES, penetration depth and Raman experiments are consistent with a nonmonotonic d_{x^2-y^2} superconducting order parameter proposed in Phys. Rev. Lett., 88, 107002 (2002).Comment: Reply to Comment by F. Venturini, R. Hackl, and U. Michelucci cond-mat/020541

Rain erosion numerical modeling applied to multi-MW off-shore wind turbine

In this work, the authors present a numerical prediction of erosion on two different blade geometry of a 6 MW HAWT designed for different aerodynamic loading, with the aim of studying their sensitiveness to erosion. First, the fully 3D simulations are performed using an Euler-Lagrangian approach. Flow field simulations are carried out with the open-source code OpenFOAM, based on a finite volume approach, using Multiple Reference Frame methodology. Reynolds Averaged Navier- Stokes equations for incompressible flow were solved with a k-ε turbulence model. An in-house code (P-Track) is used to compute the rain drops transport and dispersion, adopting the Particle Cloud Tracking approach (PCT). The PCT was used by some of the authors in previous works (Corsini et al., 2012; Corsini et al., 2014) to predict erosion on both axial and centrifugal fans, obtaining satisfactory results. The PCT allows to simulate a huge number of transported phase tracking just few cloud trajectories, thus resulting in reduction of computational time comparing with single particle tracking approach. Erosion is modelled accounting for the main quantities affecting the phenomenon, which is impact velocity and angle, and material properties of the target surface. Results provide the regions of the two blades more sensitive to erosion, and the effect of the blade geometry on erosion attitude

Rain erosion numerical modeling applied to multi-MW off-shore wind turbine

In this work, the authors present a numerical prediction of erosion on two different blade geometry of a 6 MW HAWT designed for different aerodynamic loading, with the aim of studying their sensitiveness to erosion. First, the fully 3D simulations are performed using an Euler-Lagrangian approach. Flow field simulations are carried out with the open-source code OpenFOAM, based on a finite volume approach, using Multiple Reference Frame methodology. Reynolds Averaged Navier- Stokes equations for incompressible flow were solved with a k-ε turbulence model. An in-house code (P-Track) is used to compute the rain drops transport and dispersion, adopting the Particle Cloud Tracking approach (PCT). The PCT was used by some of the authors in previous works (Corsini et al., 2012; Corsini et al., 2014) to predict erosion on both axial and centrifugal fans, obtaining satisfactory results. The PCT allows to simulate a huge number of transported phase tracking just few cloud trajectories, thus resulting in reduction of computational time comparing with single particle tracking approach. Erosion is modelled accounting for the main quantities affecting the phenomenon, which is impact velocity and angle, and material properties of the target surface. Results provide the regions of the two blades more sensitive to erosion, and the effect of the blade geometry on erosion attitude

Effects of three different stimulations (acupuncture, moxibustion, acupuncture plus moxibustion) of BL.67 acupoint at small toe on fetal behavior of breech presentation

The aim of the study was to evaluate cardiovascular effects and fetal behavior during moxibustion, acupuncture or acupuncture plus moxibustion applied on the BL.67 acupoint of women (beside the outer corner of the 5th toenail) in fetal breech presentation. During the acupoint stimulation (20 min, two times a week), the women were submitted to computerized non-stress test. Fourteen cases were treated by both acupuncture and moxibustion, 15 cases by moxibustion and 10 cases by acupuncture. In 56% of cases, fetal position was converted from breech position to cephalic one; the success share was 80% for moxibustion, 28% for acupuncture, 57% for acupuncture plus moxibustion; the conversion, on average, was achieved after 3 sessions. Statistical analysis indicated that acupuncture plus moxibustion was able to reduce fetal heart rate during the application of stimuli while acupuncture and moxibustion separately did not affect such parameter. Moreover, moxibustion and acupuncture with moxibustion reduced fetal movements while acupuncture only appears ineffective. The present study suggests that fetal movements were reduced by both acupuncture plus moxibustion and moxibustion and that fetal heart rate was reduced just by acupuncture plus moxibustion. The mechanisms leading the effect on fetal heart rate and fetal movements remain to be clarified. Even though further studies are needed, such preliminar report mainly investigated the impact of different stimula on the BL.67 acupoint. Unfortunately these small series of data do not allow us to draw any conclusion about the effectiveness of the different treatments

Thermomagnetic history effects in SmMn2_2Ge2_2

The intermetallic compound SmMn$_2$Ge$_2$, displaying multiple magnetic phase transitions, is being investigated in detail for its magnetization behavior near the 145 K first order ferromagnetic to antiferromagnetic transition occuring on cooling, in particular for thermomagnetic history effects in the magnetization data. The most unusual finding is that the thermomagnetic irreversibility, [= M$^{FCW}$(T)-M$^{ZFC}$(T)] at 135 K is higher in intermediate magnetic field strengths. By studying the response of the sample (i.e., thermomagnetic irreversibility and thermal hysteresis) to different histories of application of magnetic field and temperature, we demonstrate how the supercooling and superheating of the metastable magnetic phases across the first order transition at 145 K contribute to overall thermomagnetic irreversibility.Comment: 15 pages, 5 figures, to appear in Physical Review

Complex Systems Science: Dreams of Universality, Reality of Interdisciplinarity

Using a large database (~ 215 000 records) of relevant articles, we empirically study the "complex systems" field and its claims to find universal principles applying to systems in general. The study of references shared by the papers allows us to obtain a global point of view on the structure of this highly interdisciplinary field. We show that its overall coherence does not arise from a universal theory but instead from computational techniques and fruitful adaptations of the idea of self-organization to specific systems. We also find that communication between different disciplines goes through specific "trading zones", ie sub-communities that create an interface around specific tools (a DNA microchip) or concepts (a network).Comment: Journal of the American Society for Information Science and Technology (2012) 10.1002/asi.2264