453 research outputs found
Surface water floods in Switzerland: what insurance claim records tell us about the damage in space and time
Surface water floods (SWFs) have received increasing attention in the recent
years. Nevertheless, we still know relatively little about where, when and
why such floods occur and cause damage, largely due to a lack of data but
to some degree also because of terminological ambiguities. Therefore, in a
preparatory step, we summarize related terms and identify the need for
unequivocal terminology across disciplines and international boundaries in
order to bring the science together. Thereafter, we introduce a large
(n = 63 117), long (10–33 years) and representative
(48 % of all Swiss buildings covered) data set of spatially explicit
Swiss insurance flood claims. Based on registered flood damage to buildings,
the main aims of this study are twofold: First, we introduce a method to
differentiate damage caused by SWFs and fluvial floods based on the
geographical location of each damaged object in relation to flood hazard maps
and the hydrological network. Second, we analyze the data with respect to
their spatial and temporal distributions aimed at quantitatively answering
the fundamental questions of how relevant SWF damage really is, as well as
where and when it occurs in space and time.
This study reveals that SWFs are responsible for at least 45 % of the
flood damage to buildings and 23 % of the associated direct tangible
losses, whereas lower losses per claim are responsible for the lower loss
share. The Swiss lowlands are affected more heavily by SWFs than the alpine
regions. At the same time, the results show that the damage claims and
associated losses are not evenly distributed within each region either.
Damage caused by SWFs occurs by far most frequently in summer in almost all
regions. The normalized SWF damage of all regions shows no significant upward
trend between 1993 and 2013. We conclude that SWFs are in fact a highly
relevant process in Switzerland that should receive similar attention like
fluvial flood hazards. Moreover, as SWF damage almost always coincides with
fluvial flood damage, we suggest considering SWFs, like fluvial floods, as integrated processes of
our catchments
Beam Performance and Luminosity Limitations in the High-Energy Storage Ring (HESR)
The High-Energy Storage Ring (HESR) of the future International Facility for
Antiproton and Ion Research (FAIR) at GSI in Darmstadt is planned as an
antiproton synchrotron and storage ring in the momentum range from 1.5 to 15
GeV/c. An important feature of this new facility is the combination of phase
space cooled beams with dense internal targets (e.g. pellet targets), resulting
in demanding beam parameter of two operation modes: high luminosity mode with
peak luminosities up to 2*10^32 cm-2 s-1, and high resolution mode with a
momentum spread down to 10^-5, respectively. To reach these beam parameters
very powerful phase space cooling is needed, utilizing high-energy electron
cooling and high-bandwidth stochastic cooling. The effect of beam-target
scattering and intra-beam interaction is investigated in order to study beam
equilibria and beam losses for the two different operation modes.Comment: 8 pages, based on a talk presented at COULOMB'05, Accepted for
publication by Nuclear Instruments and Methods in Physics Research Section A:
Accelerators, Spectrometers, Detectors and Associated Equipmen
Experimental Test of Momentum Cooling Model Predictions at COSY and Conclusions for WASA and HESR
The High-Energy Storage Ring (HESR) of the future International Facility for
Antiproton and Ion Research (FAIR) at GSI in Darmstadt is planned as an
anti-proton cooler ring in the momentum range from 1.5 to 15 GeV/c. An
important and challenging feature of the new facility is the combination of
highly dense phase space cooled beams with internal targets. A detailed
numerical and analytical approach to the Fokker-Planck equation for
longitudinal filter cooling including the beam - target interaction has been
carried out to demonstrate the stochastic cooling capability. To gain
confidence in the model predictions a series of experimental stochastic cooling
studies with the internal target ANKE at COSY have been carried out. A
remarkable agreement between model and experiment was achieved. On this basis
longitudinal stochastic cooling simulations were performed to predict the
possibilities and limits of cooling when the newly installed WASA Pellet-target
is operated.Comment: 17 pages, 11 figures, Talk given at Symposium on Meson Physics at
COSY-11 and WASA-at-COSY, Cracow, Poland, 17-22 Jun 200
A recoil detector for the measurement of antiproton-proton elastic scattering at angles close to 90
The design and construction of a recoil detector for the measurement of
recoil protons of antiproton-proton elastic scattering at scattering angles
close to 90 are described. The performance of the recoil detector has
been tested in the laboratory with radioactive sources and at COSY with proton
beams by measuring proton-proton elastic scattering. The results of laboratory
tests and commissioning with beam are presented. Excellent energy resolution
and proper working performance of the recoil detector validate the conceptual
design of the KOALA experiment at HESR to provide the cross section data needed
to achieve a precise luminosity determination at the PANDA experiment.Comment: 10 pages, 15 figure
High precision beam momentum determination in a synchrotron using a spin resonance method
In order to measure the mass of the eta meson with high accuracy using the
d+p -> 3He+eta reaction, the momentum of the circulating deuteron beam in the
Cooler Synchrotron COSY of the Forschungszentrum Juelich has to be determined
with unprecedented precision. This has been achieved by studying the spin
dynamics of the polarized deuteron beam. By depolarizing the beam through the
use of an artificially induced spin resonance, it was possible to evaluate its
momentum p with a precision of dp/p < 10-4 for a momentum of roughly 3 GeV/c.
Different possible sources of error in the application of the spin resonance
method are discussed in detail and its possible use during a standard
experiment is considered.Comment: 10 pages, 6 figures, 2 tables, published versio
Measurement of the analyzing powers in pd elastic and pn quasi-elastic scattering at small angles
The analyzing powers in proton-deuteron elastic and proton-neutron
quasi-elastic scattering have been measured at small angles using a polarized
proton beam at the COSY storage ring incident on an unpolarized deuterium
target. The data were taken at 796MeV and five higher energies from 1600MeV to
2400MeV. The analyzing power in pd elastic scattering was studied by detecting
the low energy recoil deuteron in telescopes placed symmetrically in the COSY
plane to the left and right of the beam whereas for pn quasi-elastic scattering
a low energy proton was registered in one of the telescopes in coincidence with
a fast scattered proton measured in the ANKE magnetic spectrometer. Though the
experiment explores new domains, the results are consistent with the limited
published information.Comment: 10 pages with 8 figure
Evaluating retinal and choroidal perfusion changes after isometric and dynamic activity using optical coherence tomography angiography
Optical coherence tomography angiography (OCTA) is a non-invasive tool for imaging and quantifying the retinal and choroidal perfusion state in vivo. This study aimed to evaluate the acute effects of isometric and dynamic exercise on retinal and choroidal sublayer perfusion using OCTA. A pilot study was conducted on young, healthy participants, each of whom performed a specific isometric exercise on the first day and a dynamic exercise the day after. At baseline and immediately after the exercise, heart rate (HR), mean arterial pressure (MAP), superficial capillary plexus perfusion (SCPP), deep capillary plexus perfusion (DCPP), choriocapillaris perfusion (CCP), Sattlers’s layer perfusion (SLP), and Haller’s layer perfusion (HLP) were recorded. A total of 34 eyes of 34 subjects with a mean age of 32.35 ± 7.87 years were included. HR as well as MAP increased significantly after both types of exercise. Both SCPP and DCPP did not show any significant alteration due to isometric or dynamic exercise. After performing dynamic exercise, CCP, SLP, as well as HLP significantly increased. Changes in MAP correlated significantly with changes in HLP after the dynamic activity. OCTA-based analysis in healthy adults following physical activity demonstrated a constant retinal perfusion, supporting the theory of autoregulatory mechanisms. Dynamic exercise, as opposed to isometric activity, significantly changed choroidal perfusion. OCTA imaging may represent a novel and sensitive tool to expand the diagnostic spectrum in the field of sports medicine
Absence of spin dependence in the final state interaction of the d(pol) p --> 3He eta reaction
The deuteron tensor analysing power t_{20} of the d(pol) p --> 3He eta
reaction has been measured at the COSY-ANKE facility in small steps in excess
energy Q up to Q = 11 MeV. Despite the square of the production amplitude
varying by over a factor of five through this range, t_{20} shows little or no
energy dependence. This is evidence that the final state interaction causing
the energy variation is not influenced by the spin configuration in the
entrance channel. The weak angular dependence observed for t_{20} provides
useful insight into the amplitude structure near threshold.Comment: 5 pages, 4 figure
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