13,486 research outputs found
Dynamical reentrance and geometry imposed quantization effects in Nb-AlOx-Nb Josephson junction arrays
In this paper, we report on different phenomena related to the magnetic
properties of artificially prepared highly ordered (periodic) two-dimensional
Josephson junction arrays (2D-JJA) of both shunted and unshunted Nb-AlOx-Nb
tunnel junctions. By employing mutual-inductance measurements and using a
high-sensitive bridge, we have thoroughly investigated (both experimentally and
theoretically) the temperature and magnetic field dependence of complex AC
susceptibility of 2D-JJA. We also demonstrate the use of the scanning SQUID
microscope for imaging the local flux distribution within our unshunted arrays
Early Aspects at ICSE 2007: Workshop on Aspect-Oriented Requirements Engineering and Architecture Design
The “Early Aspects @ ICSE’07” is the 11th workshop in the series of Early Aspects workshops [1] which focuses on aspect identification during the requirements engineering and architecture derivation activities. The specific aim of the present workshop is twofold: (a) to initiate creation of an Early Aspects application demonstration and comparisons benchmark; and (b) to solicit submission of new
research
Analysis of the velocity field of granular hopper flow
We report the analysis of radial characteristics of the flow of granular
material through a conical hopper. The discharge is simulated for various
orifice sizes and hopper opening angles. Velocity profiles are measured along
two radial lines from the hopper cone vertex: along the main axis of the cone
and along its wall. An approximate power law dependence on the distance from
the orifice is observed for both profiles, although differences between them
can be noted. In order to quantify these differences, we propose a Local Mass
Flow index that is a promising tool in the direction of a more reliable
classification of the flow regimes in hoppers
Timed Consistent Network Updates
Network updates such as policy and routing changes occur frequently in
Software Defined Networks (SDN). Updates should be performed consistently,
preventing temporary disruptions, and should require as little overhead as
possible. Scalability is increasingly becoming an essential requirement in SDN.
In this paper we propose to use time-triggered network updates to achieve
consistent updates. Our proposed solution requires lower overhead than existing
update approaches, without compromising the consistency during the update. We
demonstrate that accurate time enables far more scalable consistent updates in
SDN than previously available. In addition, it provides the SDN programmer with
fine-grained control over the tradeoff between consistency and scalability.Comment: This technical report is an extended version of the paper "Timed
Consistent Network Updates", which was accepted to the ACM SIGCOMM Symposium
on SDN Research (SOSR) '15, Santa Clara, CA, US, June 201
Counterion density profiles at charged flexible membranes
Counterion distributions at charged soft membranes are studied using
perturbative analytical and simulation methods in both weak coupling
(mean-field or Poisson-Boltzmann) and strong coupling limits. The softer the
membrane, the more smeared out the counterion density profile becomes and
counterions pentrate through the mean-membrane surface location, in agreement
with anomalous scattering results. Membrane-charge repulsion leads to a
short-scale roughening of the membrane.Comment: 4 pages, 4 figure
Infrared phonon dynamics of multiferroic BiFeO3 single crystal
We discuss the first infrared reflectivity measurement on a BiFeO3 single
crystal between 5 K and room temperature. The 9 predicted ab-plane E phonon
modes are fully and unambiguously determined. The frequencies of the 4 A1
c-axis phonons are found. These results settle issues between theory and data
on ceramics. Our findings show that the softening of the lowest frequency E
mode is responsible for the temperature dependence of the dielectric constant,
indicating that the ferroelectric transition in BiFeO3 is soft-mode driven.Comment: 5 pages (figures included
Available phosphorus and potassium status of soils of Amazonas State.
With the objective of presenting more substantial data, results from 3,340 soil samples collected during the past 30 years were compiled by the Laboratory of Soil Fertility of the Brazilian Agricultural Research Enterprise (Embrapa Western Amazon (Manaus)
Invariant measures for Cherry flows
We investigate the invariant probability measures for Cherry flows, i.e.
flows on the two-torus which have a saddle, a source, and no other fixed
points, closed orbits or homoclinic orbits. In the case when the saddle is
dissipative or conservative we show that the only invariant probability
measures are the Dirac measures at the two fixed points, and the Dirac measure
at the saddle is the physical measure. In the other case we prove that there
exists also an invariant probability measure supported on the quasi-minimal
set, we discuss some situations when this other invariant measure is the
physical measure, and conjecture that this is always the case. The main
techniques used are the study of the integrability of the return time with
respect to the invariant measure of the return map to a closed transversal to
the flow, and the study of the close returns near the saddle.Comment: 12 pages; updated versio
Efeito do uso de efluente de esgoto tratado sobre a resistência do solo à penetração em pastagem.
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