12,805 research outputs found
Automation and robotics for COLUMBUS: An implementation concept for the free flying laboratory (MTFF)
With nearly forty percent of the funding, Germany is the main contributor to the European COLUMBUS Programme, followed by Italy, France and further ESA member states. The COLUMBUS elements are the Attached Laboratory (APM) to be permanently attached to the Space Station FREEDOM, the polar platform (PPF) and the Man Tended Free Flyer (MTFF). The latter element is regarded to be of special interest for the German micro-g community. Until now the implementation of A&R Technologies has not been included as part of the system concept for the COLUMBUS laboratory modules. Yet especially for the Free Flyer, a high degree of A&R will be indispensible. An A&R system concept and implementation options for A&R are given to make the COLUMBUS labs 'intelligent' laboratories in orbit
Investigation of scaling properties of hysteresis in Finemet thin films
We study the behavior of hysteresis loops in Finemet
FeCuNbSiB thin films by using a fluxometric setup
based on a couple of well compensated pickup coils. The presence of scaling
laws of the hysteresis area is investigated as a function of the amplitude and
frequency of the applied field, considering sample thickness from about 20 nm
to 5 m. We do not observe any scaling predicted by theoretical models,
while dynamic loops show a logarithmic dependence on the frequency.Comment: 2 pages, 2 figure
Semileptonic Decays of D and B Mesons
We report results of our ongoing investigation concerning semileptonic decays
of heavy pseudoscalar mesons into pseudoscalar and vector mesons. Particular
attention is paid to uncertainties in the and the heavy quark mass
dependence of formfactors. Moreover we present a non-perturbative test to the
LMK current renormalization scheme for vector current transition matrix
elements and find remarkable agreement.Comment: 3 pages, uuencoded, contribution to Lat 9
Dynamic hysteresis in Finemet thin films
We performed a series of dynamic hysteresis measurements on three series of
Finemet films with composition FeCuNbSiB, using
both the longitudinal magneto-optical Kerr effect (MOKE) and the inductive
fluxometric method. The MOKE dynamic hysteresis loops show a more marked
variability with the frequency than the inductive ones, while both measurements
show a similar dependence on the square root of frequency. We analyze these
results in the frame of a simple domain wall depinning model, which accounts
for the general behavior of the data.Comment: 3 pages, 3 figure
A Statistical Model for Simultaneous Template Estimation, Bias Correction, and Registration of 3D Brain Images
Template estimation plays a crucial role in computational anatomy since it
provides reference frames for performing statistical analysis of the underlying
anatomical population variability. While building models for template
estimation, variability in sites and image acquisition protocols need to be
accounted for. To account for such variability, we propose a generative
template estimation model that makes simultaneous inference of both bias fields
in individual images, deformations for image registration, and variance
hyperparameters. In contrast, existing maximum a posterori based methods need
to rely on either bias-invariant similarity measures or robust image
normalization. Results on synthetic and real brain MRI images demonstrate the
capability of the model to capture heterogeneity in intensities and provide a
reliable template estimation from registration
Beautiful Baryons from Lattice QCD
We perform a lattice study of heavy baryons, containing one () or
two -quarks (). Using the quenched approximation we obtain for the
mass of
The mass splitting between the and the B-meson is found to increase
by about 20\% if the light quark mass is varied from the chiral limit to the
strange quark mass.Comment: 11 pages, Figures obtained upon request from [email protected]
New challenges in studying nutrition-disease interactions in the developing world.
Latest estimates indicate that nutritional deficiencies account for 3 million child deaths each year in less-developed countries. Targeted nutritional interventions could therefore save millions of lives. However, such interventions require careful optimization to maximize benefit and avoid harm. Progress toward designing effective life-saving interventions is currently hampered by some serious gaps in our understanding of nutrient metabolism in humans. In this Personal Perspective, we highlight some of these gaps and make some proposals as to how improved research methods and technologies can be brought to bear on the problems of undernourished children in the developing world
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