2,458 research outputs found
"Magnetoscan": A Modified Hall Probe Scanning Technique for the Detection of Inhomogeneities in Bulk High Temperature Superconductors
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
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
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
We study discrete-time quantum walks on -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 . We
solve the model analytically and observe that for prime there exists a
strong complementarity property between the eigenvectors of two quantum walk
evolution operators that act in the -dimensional Hilbert space. Namely, if
is prime the corresponding eigenvectors of the evolution operators obey
for and for all
and . 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
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
- …