2,458 research outputs found

    "Magnetoscan": A Modified Hall Probe Scanning Technique for the Detection of Inhomogeneities in Bulk High Temperature Superconductors

    Full text link
    We present a novel technique for the investigation of local variations of the critical current density in large bulk superconductors. In contrast to the usual Hall probe scanning technique, the sample is not magnetized as a whole before the scan, but locally by a small permanent magnet, which is fixed near the Hall probe, during the scanning process. The resulting signal can be interpreted as a qualitative measure of the local shielding currents flowing at the surface.Comment: 8 pages, 4 figure

    Interlayer Exchange Coupling in (Ga,Mn)As-based Superlattices

    Full text link
    The interlayer coupling between (Ga,Mn)As ferromagnetic layers in all-semiconductor superlattices is studied theoretically within a tight-binding model, which takes into account the crystal, band and magnetic structure of the constituent superlattice components. It is shown that the mechanism originally introduced to describe the spin correlations in antiferromagnetic EuTe/PbTe superlattices, explains the experimental results observed in ferromagnetic semiconductor structures, i.e., both the antiferromagnetic coupling between ferromagnetic layers in IV-VI (EuS/PbS and EuS/YbSe) superlattices as well as the ferromagnetic interlayer coupling in III-V ((Ga,Mn)As/GaAs) multilayer structures. The model allows also to predict (Ga,Mn)As-based structures, in which an antiferromagnetic interlayer coupling could be expected.Comment: 4 pages, 3 figure

    An Assessment of the Academic Impact of Shock Society Members

    Get PDF
    Professional society membership enhances career development and productivity by offering opportunities for networking and learning about recent advances in the field. The quality and contribution of such societies can be measured in part through the academic productivity, career status, and funding success rates of their members. Here, using Scopus, NIH RePORTER, and departmental websites, we compare characteristics of the Shock Society membership to those of the top 55 NIH-funded American university and hospital-based departments of surgery. Shock Society members' mean number of publications, citations and H-indices were all significantly higher than those of non-members in surgery departments (P < 0.001). A higher percentage of members also have received funding from the NIH (42.5% vs. 18.5%, P < 0.001). Regression analysis indicated that members were more likely to have NIH funding compared with non-members (OR 1.46, 95% CI 1.12-1.916). Trauma surgeons belonging to the Shock Society had a higher number of publications and greater NIH funding than those who did not (130.4 vs. 42.7, P < 0.001; 40.4% vs. 8.5%, P < 0.001). Aggregate academic metrics from the Shock Society were superior to those of the Association for Academic Surgery and generally for the Society of University Surgeons as well. These data indicate that the Shock Society represents a highly academic and productive group of investigators. For surgery faculty, membership is associated with greater academic productivity and career advancement. While it is difficult to ascribe causation, certainly the Shock Society might positively influence careers for its members

    Complementarity in quantum walks

    Full text link
    We study discrete-time quantum walks on dd-cycles with a position and coin-dependent phase-shift. Such a model simulates a dynamics of a quantum particle moving on a ring with an artificial gauge field. In our case the amplitude of the phase-shift is governed by a single discrete parameter qq. We solve the model analytically and observe that for prime dd there exists a strong complementarity property between the eigenvectors of two quantum walk evolution operators that act in the 2d2d-dimensional Hilbert space. Namely, if dd is prime the corresponding eigenvectors of the evolution operators obey ∣⟨vq∣vq′′⟩∣≤1/d|\langle v_q|v'_{q'} \rangle| \leq 1/\sqrt{d} for q≠q′q\neq q' and for all ∣vq⟩|v_q\rangle and ∣vq′′⟩|v'_{q'}\rangle. We also discuss dynamical consequences of this complementarity. Finally, we show that the complementarity is still present in the continuous version of this model, which corresponds to a one-dimensional Dirac particle.Comment: 5+7 pages, 2 figures, comments welcom

    Universal design for instruction: Understanding faculty practices and needs

    Get PDF
    The purposes of this short report are to describe key principles of UDL and UDI and to describe the findings of a pilot survey study that focused on faculty members practices and needs in the areas of UDL/UDI. Limited previous research is available related to faculty perceptions of UDI/UDL in higher education settings. One exception is a study conducted by Vreeburg-Izzo, Murray, and Novak (2008). Vreeburg-Izzo et al. conducted a survey, coupled with follow-up focus groups, with faculty and graduate teaching assistants that examined the (a) climate of instructional settings for students with disabilities, and (b) perceived needs for professional development among faculty and administrators related to providing educational access for all students. Of the 1,150 survey instruments distributed, 271 were completed and returned. Results from the survey indicated that participants were primarily interested in training on UDL but also expressed interested in training on Web accessibility and distance education. Subsequent focus groups revealed that faculty (a) often felt uncertain about meeting the needs of diverse students in the classroom; (b) employed several strategies to enhance teaching and learning, but did not connect this to UDL; and (c) desired both training and technical assistance to help promote educational access for all students
    • …
    corecore