1,499 research outputs found
Characterisation of the Etching Quality in Micro-Electro-Mechanical Systems by Thermal Transient Methodology
Our paper presents a non-destructive thermal transient measurement method
that is able to reveal differences even in the micron size range of MEMS
structures. Devices of the same design can have differences in their
sacrificial layers as consequence of the differences in their manufacturing
processes e.g. different etching times. We have made simulations examining how
the etching quality reflects in the thermal behaviour of devices. These
simulations predicted change in the thermal behaviour of MEMS structures having
differences in their sacrificial layers. The theory was tested with
measurements of similar MEMS devices prepared with different etching times. In
the measurements we used the T3Ster thermal transient tester equipment. The
results show that deviations in the devices, as consequence of the different
etching times, result in different temperature elevations and manifest also as
shift in time in the relevant temperature transient curves.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
On the mechanism of irradiation enhanced exchange bias
By means of layer resolved ion irradiation the mechanisms involved in the
irradiation driven modifications of the exchange bias effect in NiFe/FeMn
bilayers have been investigated. It is shown that not only the locations of the
defects but also the magnetic coupling between both layers during the
irradiation process is of crucial importance. This requires an extension of
current models accounting for defects in exchange bias systems.Comment: 3 pages, 3 figures, revised version, added results from further
structural characterization by TEM, submitted to Europhysics Letter
The database BIOSCAT: a tool for structure research by scattering and hydrodynamic methods
The crystal structures of a large number of proteins and nucleic acids are known and the corresponding sets of coordinates are stored in the Brookhaven Protein Data Bank. For structure investigations of biological macromolecules in solution, scattering and hydrodynamical methods are powerful biophysical tools when starting the data interpretation on the basis of the crystal structure of the molecules. The database BIOSCAT covers the main structural parameters estimable by X-ray scattering, translation and rotation diffusion methods and the X-ray scattering intensities and low- and high-resolution real-space electron distance distribution functions of 70 biological macromolecules and of oligonucleotides in standard conformation. The parameters and the scattered intensities are calculated from the atomic coordinates using the improved cube method and the real-space functions are estimated via a termination-error-reduced Fourier sine transformation. The database access is organized by the program PASSDB, which can generally be used for 'readable' databases. A simple query language allows enquiries into the database without knowledge of a programming language. The program CONVSQL converts the database into normalized relations that can be handled by structured query languages (SQLs)
The Texture of Surficial Sediments in Western Long Island Sound off the Norwalk Islands, Connecticut
Grain-size analyses were performed on 69 samples from western Long Island Sound. The relative grain-size frequency distributions and related statistics are reported herein. Descriptions of the benthic character from video tapes and still camera photographs of the bottom at these stations, and 33 others, are also presented. The southern and eastern parts of the study area are dominated by poorly sorted clayey silts that have nearly symmetrical distributions. Gravelly sediments are prevalent in the shallow northwestern part of the study area, but are also present in central part of the study area. Bands of sand, silty sand, and sand-silt-clay occur on the flanks of the gravelly areas
Assessing the Quality of Actions
While recent advances in computer vision have provided reliable methods to recognize actions in both images and videos, the problem of assessing how well people perform actions has been largely unexplored in computer vision. Since methods for assessing action quality have many real-world applications in healthcare, sports, and video retrieval, we believe the computer vision community should begin to tackle this challenging problem. To spur progress, we introduce a learning-based framework that takes steps towards assessing how well people perform actions in videos. Our approach works by training a regression model from spatiotemporal pose features to scores obtained from expert judges. Moreover, our approach can provide interpretable feedback on how people can improve their action. We evaluate our method on a new Olympic sports dataset, and our experiments suggest our framework is able to rank the athletes more accurately than a non-expert human. While promising, our method is still a long way to rivaling the performance of expert judges, indicating that there is significant opportunity in computer vision research to improve on this difficult yet important task.National Science Foundation (U.S.). Graduate Research FellowshipGoogle (Firm) (Research Award)United States. Office of Naval Research. Multidisciplinary University Research Initiative (N000141010933
Break junctions of the heavy-fermion superconductors
Mechanical-controllable break junctions of the heavy-fermion superconductors
can show Josephson-like superconducting anomalies. But a systematic study on
the contact size demonstrates that these anomalies are mainly due to Maxwell's
resistance being suppressed in the superconducting heavy-fermion phase. Up to
day, we could not find any superconducting features by vacuum-tunnelling
spectroscopy, providing further evidence for the pair-breaking effect of the
heavy-fermion interfaces.Comment: 5 pages, EPS figures included, REVTeX, to be published in Physica B
9
Glueball Production in Peripheral Heavy-Ion Collisions
The method of equivalent quanta is applied both to photon-photon and, by
analogy, to double pomeron exchange in heavy-ion collisions. This
Weizs\"acker-Williams approach is used to calculate production cross sections
for the glueball candidate meson via photon-photon and
pomeron-pomeron fusion in peripheral heavy-ion collisions at both RHIC and LHC
energies. The impact-parameter dependence for total and elastic cross sections
are presented, and are compared to results for proton-proton collisions.Comment: 15 pages, 6 figure
Control of interlayer exchange coupling in Fe/Cr/Fe trilayers by ion beam irradiation
The manipulation of the antiferromagnetic interlayer coupling in the
epitaxial Fe/Cr/Fe(001) trilayer system by moderate 5 keV He ion beam
irradiation has been investigated experimentally. It is shown that even for
irradiation with very low fluences (10^14 ions/cm^2) a drastic change in
strength of the coupling appears. For thin Cr-spacers (below 0.6 - 0.7 nm) the
coupling strength decreases with fluence, becoming ferromagnetic for fluences
above (2x10^14 ions/cm^2). The effect is connected with the creation of
magnetic bridges in the layered system due to atomic exchange events caused by
the bombardment. For thicker Cr spacers (0.8 - 1.2 nm) an enhancement of the
antiferromagnetic coupling strength is found. A possible explanation of the
enhancement effect is given.Comment: Submitted to PR
The controversy in the process: potential scattering or resonance ?
The reaction shows a broad peak at 1.5
GeV in the channel which has no counterpart in the
channel. This "resonance" is considered as a candidate for a
state in the "s-channel". We show, however, that it can also
be explained by potential scattering of via the -
exchange in the "t-channel".Comment: 12 pages, latex, 3 postscript figures, to appear in Zeitschrift fur
Physi
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