1,930 research outputs found
Combined in vivo recording of neural signals and iontophoretic injection of pathway tracers using a hollow silicon microelectrode
Circadian pattern and burstiness in mobile phone communication
The temporal communication patterns of human individuals are known to be
inhomogeneous or bursty, which is reflected as the heavy tail behavior in the
inter-event time distribution. As the cause of such bursty behavior two main
mechanisms have been suggested: a) Inhomogeneities due to the circadian and
weekly activity patterns and b) inhomogeneities rooted in human task execution
behavior. Here we investigate the roles of these mechanisms by developing and
then applying systematic de-seasoning methods to remove the circadian and
weekly patterns from the time-series of mobile phone communication events of
individuals. We find that the heavy tails in the inter-event time distributions
remain robustly with respect to this procedure, which clearly indicates that
the human task execution based mechanism is a possible cause for the remaining
burstiness in temporal mobile phone communication patterns.Comment: 17 pages, 12 figure
Correlated dynamics in egocentric communication networks
We investigate the communication sequences of millions of people through two
different channels and analyze the fine grained temporal structure of
correlated event trains induced by single individuals. By focusing on
correlations between the heterogeneous dynamics and the topology of egocentric
networks we find that the bursty trains usually evolve for pairs of individuals
rather than for the ego and his/her several neighbors thus burstiness is a
property of the links rather than of the nodes. We compare the directional
balance of calls and short messages within bursty trains to the average on the
actual link and show that for the trains of voice calls the imbalance is
significantly enhanced, while for short messages the balance within the trains
increases. These effects can be partly traced back to the technological
constrains (for short messages) and partly to the human behavioral features
(voice calls). We define a model that is able to reproduce the empirical
results and may help us to understand better the mechanisms driving technology
mediated human communication dynamics.Comment: 7 pages, 6 figure
High‐throughput competitive fluorescence polarization assay reveals functional redundancy in the S100 protein family
CODEX-CT-2 experiment: Long term treatment in high temperature hydrogen and water quenching of a fuel bundle KFKI-2008-02/G
The simulation of the Paks-2 incident was carried out in the frame of an experimental programme in
the CODEX facility with electrically heated fuel rod bundles. The main boundary conditions for the
CODEX-CT-2 were similar to the previous CODEX-CT-1 test. The most significant difference
between the two tests was the operation of the air let down valve that was open in the first test and
closed in the second one. In the second test the hydrogen produced in the Zr-steam reaction could not
escape from the test section and it prevented the access of steam to the Zr surfaces and caused much
less oxidation than was observed in the first tests. The final quench by water led to temperature
excursion in the bundle and in the shroud. The final state of the bundle was very brittle, the fuel rods
and the shroud were cracked and fragmented
CODEX-CT-1 experiment: Quenching of fuel bundle after long term oxidation in hydrogen rich steam KFKI-2008-01/G
The cleaning tank incident at the unit 2 of Paks NPP in 2003 resulted in severe fuel damage of 30
assemblies. The fuel rods heated up due to insufficient cooling and the zirconium components
suffered heavy oxidation. Opening of the tank and quenching of the assemblies by cold water led to
fragmentation of brittle zirconium components. Due to the poor instrumentation there were many
open questions concerning the course of the incident and the behaviour of fuel assemblies. In order to
improve the understanding of the phenomena that took place during the Paks-2 incident integral tests
have been carried out in the CODEX (Core Degradation Experiment) facility. The tests simulated the
whole scenario of the incident using electrically heated fuel rods. The final state of the fuel rods
showed many similarities with the conditions observed after the incident at the NPP and for this
reason it is very probable that the thermal conditions and chemical reactions were also similar in the
tests and in the incident. The post-test examination of CODEX-CT-1 bundle indicated that the high
degree of embrittlement was a common result of oxidation and hydrogen uptake by the Zr
components
Pre-Excitation Studies for Rubidium-Plasma Generation
The key element in the Proton-Driven-Plasma-Wake-Field-Accelerator (AWAKE)
project is the generation of highly uniform plasma from Rubidium vapor. The
standard way to achieve full ionization is to use high power laser which can
assure the over-barrier-ionization (OBI) along the 10 meters long active
region. The Wigner-team in Budapest is investigating an alternative way of
uniform plasma generation. The proposed Resonance Enhanced Multi Photon
Ionization (REMPI) scheme probably can be realized by much less laser power. In
the following the resonant pre-excitations of the Rb atoms are investigated,
theoretically and the status report about the preparatory work on the
experiment are presented.Comment: 8 pages, 6 figures, submitted to Nucl. Inst. and Meth. in Phys. Res.
On Form Factors in nested Bethe Ansatz systems
We investigate form factors of local operators in the multi-component Quantum
Non-linear Schr\"odinger model, a prototype theory solvable by the so-called
nested Bethe Ansatz. We determine the analytic properties of the infinite
volume form factors using the coordinate Bethe Ansatz solution and we establish
a connection with the finite volume matrix elements. In the two-component
models we derive a set of recursion relations for the "magnonic form factors",
which are the matrix elements on the nested Bethe Ansatz states. In certain
simple cases (involving states with only one spin-impurity) we obtain explicit
solutions for the recursion relations.Comment: 34 pages, v2 (minor modifications
CODEX-B4C Experiment: Cored Degradation Test With Boron Carbide Control Rod KFKI-2003-01/G (2003)
The CODEX-B4C bundle test has been successfully performed on 25th May 2001 in the
framework of the COLOSS project of the EU 5th FWP. The high temperature degradation
of a VVER-1000 type bundle with B4C control rod was investigated with electrically
heated fuel rods. The experiment was carried out according to a scenario selected in
favour of methane formation. Degradation of control rod and fuel bundle took place at
temperatures ~2000 oC, cooling down of the bundle was performed in steam atmosphere.
The gas composition measurement indicated no methane production during the
experiment. High release of aerosols was detected in the high temperature oxidation
phase. The on-line measured data are collected into a database and are available for code
validation and development
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