2,554 research outputs found
Form and function in hillslope hydrology : in situ imaging and characterization of flow-relevant structures
Thanks to Elly Karle and the Engler-BunteInstitute, KIT, for the IC measurements of bromide. We are grateful to Selina Baldauf, Marcel Delock, Razije Fiden, Barbara Herbstritt, Lisei Köhn, Jonas Lanz, Francois Nyobeu, Marvin Reich and Begona Lorente Sistiaga for their support in the lab and during fieldwork, as well as Markus Morgner and Jean Francois Iffly for technical support and Britta Kattenstroth for hydrometeorological data acquisition. Laurent Pfister and Jean-Francois Iffly from the Luxembourg Institute of Science and Technology (LIST) are acknowledged for organizing the permissions for the experiments. Moreover, we thank Markus Weiler (University of Freiburg) for his strong support during the planning of the hillslope experiment and the preparation of the manuscript. This study is part of the DFG-funded CAOS project “From Catchments as Organised Systems to Models based on Dynamic Functional Units” (FOR 1598). The manuscript was substantially improved based on the critical and constructive comments of the anonymous reviewers, Christian Stamm and Alexander Zimmermann, and the editor Ross Woods during the open review process, which is highly appreciated.Peer reviewedPublisher PD
Form and function in hillslope hydrology : Characterization of subsurface ow based on response observations
Acknowledgements. We are grateful to Marcel Delock, Lisei Köhn, and Marvin Reich for their support during fieldwork, as well as Markus Morgner and Jean Francois Iffly for technical support, Britta Kattenstroth for hydrometeorological data acquisition and isotope sampling, and Barbara Herbstritt and Begoña Lorente Sistiaga for laboratory work. Laurent Pfister and Jean-Francois Iffly from the Luxembourg Institute of Science and Technology (LIST) are acknowledged for organizing the permissions for the experiments and providing discharge data for Weierbach 1 and Colpach. We also want to thank Frauke K. Barthold and the two anonymous reviewers, whose thorough remarks greatly helped to improve the manuscript. This study is part of DFG-funded CAOS project “From Catchments as Organised Systems to Models based on Dynamic Functional Units” (FOR 1598). The article processing charges for this open-access publication were covered by a Research Centre of the Helmholtz Association.Peer reviewedPublisher PD
Micro black holes in the laboratory
The possibility of creating microscopic black holes is one of the most exciting predictions
for the LHC, with potentially major consequences for our current understanding of
physics. We briefly review the theoretical motivation for micro black hole production,
and our understanding of their subsequent evolution. Recent work on modelling the
radiation from quantum-gravity-corrected black holes is also discussed
Validation of Kalman Filter alignment algorithm with cosmic-ray data using a CMS silicon strip tracker endcap
A Kalman Filter alignment algorithm has been applied to cosmic-ray data. We
discuss the alignment algorithm and an experiment-independent implementation
including outlier rejection and treatment of weakly determined parameters.
Using this implementation, the algorithm has been applied to data recorded with
one CMS silicon tracker endcap. Results are compared to both photogrammetry
measurements and data obtained from a dedicated hardware alignment system, and
good agreement is observed.Comment: 11 pages, 8 figures. CMS NOTE-2010/00
Critical adsorption at chemically structured substrates
We consider binary liquid mixtures near their critical consolute points and
exposed to geometrically flat but chemically structured substrates. The
chemical contrast between the various substrate structures amounts to opposite
local preferences for the two species of the binary liquid mixtures. Order
parameters profiles are calculated for a chemical step, for a single chemical
stripe, and for a periodic stripe pattern. The order parameter distributions
exhibit frustration across the chemical steps which heals upon approaching the
bulk. The corresponding spatial variation of the order parameter and its
dependence on temperature are governed by universal scaling functions which we
calculate within mean field theory. These scaling functions also determine the
universal behavior of the excess adsorption relative to suitably chosen
reference systems
A comparative investigation of the efficacy of CO2 and high power diode lasers for the forming of EN3 mild steel sheets
A comparative investigation of the effectiveness of a high power diode laser (HPDL) and a CO2 laser for the forming of thin section EN3 mild steel sheet has been conducted. The buckling mechanism was identified as the laser forming mechanism responsible for the induced bending. For both lasers it was found that the induced bending angles increased with an increasing number of irradiations and high laser powers, whilst decreasing as the traverse speed was increased. Also, it was apparent from the experimental results that the laser bending angle was only linearly proportional to the number of irradiations when the latter was small due to local material thickening along the bend edge with a high number of irradiations. Owing to the mild steel’s greater beam absorption at the HPDL wavelength, larger bending angles were induced when using the HPDL. However, under certain conditions the performance of the CO2 laser in terms of induced bending angle was seen to approach that of the HPDL. Nevertheless, similar results between the two lasers were only achieved with increasing irradiations, thus it was concluded that the efficacy of the HPDL was higher than that of the CO2 laser insofar as it was more efficient. From graphical results and the employment of an analytical procedure, the laser line energy range in which accurate control of the HPDL bending of the mild steel sheets could be exercised efficiently was found to be 53 J mm-1 < P/v < 78 J mm-1, whilst for the CO2 laser the range was 61 J mm-1 < P/v < 85 J mm-1
Dielectronic Recombination of Fe XV forming Fe XIV: Laboratory Measurements and Theoretical Calculations
We have measured resonance strengths and energies for dielectronic
recombination (DR) of Mg-like Fe XV forming Al-like Fe XIV via N=3 -> N' = 3
core excitations in the electron-ion collision energy range 0-45 eV. All
measurements were carried out using the heavy-ion Test Storage Ring at the Max
Planck Institute for Nuclear Physics in Heidelberg, Germany. We have also
carried out new multiconfiguration Breit-Pauli (MCBP) calculations using the
AUTOSTRUCTURE code. For electron-ion collision energies < 25 eV we find poor
agreement between our experimental and theoretical resonance energies and
strengths. From 25 to 42 eV we find good agreement between the two for
resonance energies. But in this energy range the theoretical resonance
strengths are ~ 31% larger than the experimental results. This is larger than
our estimated total experimental uncertainty in this energy range of +/- 26%
(at a 90% confidence level). Above 42 eV the difference in the shape between
the calculated and measured 3s3p(^1P_1)nl DR series limit we attribute partly
to the nl dependence of the detection probabilities of high Rydberg states in
the experiment. We have used our measurements, supplemented by our
AUTOSTRUCTURE calculations, to produce a Maxwellian-averaged 3 -> 3 DR rate
coefficient for Fe XV forming Fe XIV. The resulting rate coefficient is
estimated to be accurate to better than +/- 29% (at a 90% confidence level) for
k_BT_e > 1 eV. At temperatures of k_BT_e ~ 2.5-15 eV, where Fe XV is predicted
to form in photoionized plasmas, significant discrepancies are found between
our experimentally-derived rate coefficient and previously published
theoretical results. Our new MCBP plasma rate coefficient is 19-28% smaller
than our experimental results over this temperature range
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