1,386 research outputs found

    Dynamical Coulomb blockade and spin-entangled electrons

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    We consider the production of mobile and nonlocal pairwise spin-entangled electrons from tunneling of a BCS-superconductor (SC) to two normal Fermi liquid leads. The necessary mechanism to separate the two electrons coming from the same Cooper pair (spin-singlet) is achieved by coupling the SC to leads with a finite resistance. The resulting dynamical Coulomb blockade effect, which we describe phenomenologically in terms of an electromagnetic environment, is shown to be enhanced for tunneling of two spin-entangled electrons into the same lead compared to the process where the pair splits and each electron tunnels into a different lead. On the other hand in the pair-split process, the spatial correlation of a Cooper pair leads to a current suppression as a function of distance between the two tunnel junctions which is weaker for effectively lower dimensional SCs.Comment: 5 pages, 2 figure

    Extrinsic lactose fines improve dry powder inhaler formulation performance of a cohesive batch of budesonide via agglomerate formation and consequential co-deposition

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    The aim of the study was to investigate how the fine particle content of lactose carriers prepared with different types of lactose fines regulates dry powder inhaler (DPI) formulation performance of a cohesive batch of micronised budesonide. Budesonide formulations (0.8 wt-% ) were prepared with three different lactose carriers (Lactohale (LH) LH100, 20 wt-% LH210 in LH100 and 20 wt-% LH300 in LH100). Fine particle fraction of emitted dose (FPFED) and mean mass aerodynamic diameter (MMAD) of budesonide was assessed with a Next Generation Impactor (NGI) using a Cyclohaler at 90 l/min. Morphological and chemical characteristics of particles deposited on Stage 2 were determined using a Malvern Morphologi G3-ID. The results indicate that increasing concentration of lactose fines (<4.5 μm) not only increased the FPFED but also the MMAD of budesonide, suggesting drug deposition in agglomerates. Presence of agglomerates on Stage 2 was confirmed by morphological analysis of particles. Raman analysis of material collected on Stage 2 indicated that the more fine lactose particles were available the more agglomerates of budesonide and lactose were delivered to the Stage 2. These results suggest drug-fines agglomerate formation is an important mechanism for how lactose fines improve and regulate DPI formulation performance

    Temperature-programmed reduction and dispersive X-ray absorption spectroscopy studies of CeO2-based nanopowders for intermediate-temperature Solid-Oxide Fuel Cell anodes

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    In this work, we study the influence of the average crystallite size and dopant oxide on the reducibility of CeO2-based nanomaterials. Samples were prepared from commercial Gd2O3-, Sm2O3- and Y2O3-doped CeO2 powders by calcination at different temperatures ranging between 400 and 900C and characterized by X-ray powder diffraction, transmission electron microscopy and BET specific surface area. The reducibility of the samples was analyzed by temperature-programmed reduction and in situ dispersive X-ray absorption spectroscopy techniques. Our results clearly demonstrate that samples treated at lower temperatures, of smallest average crystallite size and highest specific surface areas, exhibit the best performance, while Gd2O3-doped ceria materials display higher reducibility than Sm2O3- and Y2O3-doped CeO2

    Effect of Level of Surface Spoilage on the Nutritive Value of Maize Silage Diets

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    This study determined the effect of surface spoilage in the diet on feed intake and nutrient digestibilities using growing steers fed whole-plant maize silage-based diets. A bunker silo, 0.9 m in depth, and a 2.7 m diameter AgBag were filled with alternating loads of chopped forage. After 90 days, the bunker was sealed with a sheet of polyethylene, and this silage was designated “spoiled”. The silage in the AgBag was designated “normal”. The four diets contained 90% silage and 10% supplement (dry matter basis), and the proportions of silage in the diets were A) 100% normal, B) 75% normal: 25% spoiled; C) 50% normal: 50% spoiled; and D) 25% normal: 75% spoiled. Feed intake decreased linearly as the proportion of spoiled silage increased from 0 to 75%. Steers consuming the normal silage diet had the highest nutrient digestibilities. Spoiled silage also had negative associative effects on nutrient digestibilities, and the integrity of the forage mat in the rumen was partially destroyed

    Effects of precompetition state anxiety interventions on performance time and accuracy among amateur soccer players: Revisiting the matching hypothesis

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    In this study, we tested the matching ypothesis, which contends that administration of a cognitive or somatic anxiety intervention should be matched to a participant's dominant anxiety response. Sixty-one male soccer players (mean age 31.6 years, s=6.3) were assigned to one of four groups based on their responses to the Competitive State Anxiety Inventory-2, which was modified to include a directional scale. Interventions were randomly administered in a counterbalanced order 10 min before each performance trial on a soccer skill test. The dominantly cognitive anxious group (n=17), the dominantly somatic anxious group (n=17), and the non-anxious control intervention group (n=14) completed a baseline performance trial. The second and third trials were completed with random administration of brief cognitive and somatic interventions. The non-anxious control group (n=13) completed three trials with no intervention. A mixed-model, GroupTreatment multivariate analysis of variance indicated significant (P0.05), or performance time or accuracy (P>0.05). The present findings do not provide support for the matching hypothesis for state anxiety intensity and direction, or for performance

    Keldysh action for disordered superconductors

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    Keldysh representation of the functional integral for the interacting electron system with disorder is used to derive microscopically an effective action for dirty superconductors. In the most general case this action is a functional of the 8 x 8 matrix Q(t,t') which depends on two time variables, and on the fluctuating order parameter field and electric potential. We show that this approach reproduces, without the use of the replica trick, the well-known result for the Coulomb-induced renormalization of the electron-electron coupling constant in the Cooper channel. Turning to the new results, we calculate the effects of the Coulomb interaction upon: i) the subgap Andreev conductance between superconductor and 2D dirty normal metal, and ii) the Josephson proximity coupling between superconductive islands via such a metal. These quantities are shown to be strongly suppressed by the Coulomb interaction at sufficiently low temperatures due to both zero-bias anomaly in the density of states and disorder-enhanced repulsion in the Cooper channel.Comment: RevTeX; 39 pages + 10 EPS figure

    On reminder effects, drop-outs and dominance: evidence from an online experiment on charitable giving

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    We present the results of an experiment that (a) shows the usefulness of screening out drop-outs and (b) tests whether different methods of payment and reminder intervals affect charitable giving. Following a lab session, participants could make online donations to charity for a total duration of three months. Our procedure justifying the exclusion of drop-outs consists in requiring participants to collect payments in person flexibly and as known in advance and as highlighted to them later. Our interpretation is that participants who failed to collect their positive payments under these circumstances are likely not to satisfy dominance. If we restrict the sample to subjects who did not drop out, but not otherwise, reminders significantly increase the overall amount of charitable giving. We also find that weekly reminders are no more effective than monthly reminders in increasing charitable giving, and that, in our three months duration experiment, standing orders do not increase giving relative to one-off donations

    Mechanistic illustration: How newly‐formed blood vessels stopped by the mineral blocks of bone substitutes can be avoided by using innovative combined therapeutics

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    One major limitation for the vascularization of bone substitutes used for filling is the presence of mineral blocks. The newly-formed blood vessels are stopped or have to circumvent the mineral blocks, resulting in inefficient delivery of oxygen and nutrients to the implant. This leads to necrosis within the implant and to poor engraftment of the bone substitute. The aim of the present study is to provide a bone substitute currently used in the clinic with suitably guided vascularization properties. This therapeutic hybrid bone filling, containing a mineral and a polymeric component, is fortified with pro-angiogenic smart nano-therapeutics that allow the release of angiogenic molecules. Our data showed that the improved vasculature within the implant promoted new bone formation and that the newly-formed bone swapped the mineral blocks of the bone substitutes much more efficiently than in non-functionalized bone substitutes. Therefore, we demonstrated that our therapeutic bone substitute is an advanced therapeutical medicinal product, with great potential to recuperate and guide vascularization that is stopped by mineral blocks, and can improve the regeneration of critical-sized bone defects. We have also elucidated the mechanism to understand how the newly-formed vessels can no longer encounter mineral blocks and pursue their course of vasculature, giving our advanced therapeutical bone filling great potential to be used in many applications, by combining filling and nano-regenerative medicine that currently fall short because of problems related to the lack of oxygen and nutrients

    Spontaneous flux in a d-wave superconductor with time-reversal-symmetry-broken pairing state at {110} boundaries

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    The induction of an s-wave component in a d-wave superconductor is considered. Near the {110}-oriented edges of such a sample, the induced s-wave order parameter together with d-wave component forms a complex combination d+e^{i\phi} s, which breaks the time reversal symmetry (BTRS) of the pairing state. As a result, the spontaneous current is created. We numerically study the current distribution and the formation of the spontaneous flux induced by the current. We show that the spontaneous flux formed from a number of defect lines with {110} orientation has a measurable strength. This result may provide a unambiguous way to check the existence of BTRS pairing state at {110}-oriented boundaries.Comment: 4 pages, 2 ps-figures, content changed, references adde

    Matching schemes and public goods : a review

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    Matching schemes, where a party matches the contribution of others, reduce the effective price of a good and aim to foster its demand. We review the empirical literature on the effectiveness of these schemes in the context of public goods, especially in the field of charitable giving. As different measures of effectiveness are used, we classify results according to (i) the level of public good provision, (ii) the amount of individuals' contributions, (iii) the likelihood to give and (iv) the contribution conditional on contributing a positive amount. Generalizing results is challenging, since context specific factors matter. Predominantly, a match is found to create a significant increase in public good provision without crowding out individuals' contributions, while the effect on the likelihood of giving and contribution condition on contributing a positive amount is nonnegative. The discussion reveals several avenues for future research, as putting stronger emphasizes on long term effects, public good competition or heterogeneity in responses
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