Search results for "flux [photon]"
showing 10 items of 49 documents
The effect of high-volume online haemodiafiltration on nutritional status and body composition: the ProtEin Stores prEservaTion (PESET) study
2018
Background Compared with conventional haemodialysis (HD), online haemodiafiltration (OL-HDF) achieves a more efficient removal of uraemic toxins and reduces inflammation, which could favourably affect nutritional status. We evaluate the effect of OL-HDF on body composition and nutritional status in prevalent high-flux HD (HF-HD) patients. Methods In all, 33 adults with chronic kidney disease (CKD) Stage 5 undergoing maintenance HF-HD were assigned to post-dilution OL-HDF (n = 17) or to remain on HF-HD (n = 16, control group) for 12 months. The primary outcome was the change in lean tissue mass (LTM), intracellular water (ICW) and body cell mass (BCM) assessed by multifrequency bioimpedance …
Vortex dynamics in Bi2Sr2CaCu2O8-thin films in the presence of columnar defects
1996
With heavy ion irradiation we create continous amorphous columnar defects in Bi2Sr2CaCu2O8-thin films. With regard to a reliable comparison of irradiation effects three of four identical striplines on the same samples were exposed to different irradiation procedures. We performed irradiations as well parallel as under different angles with respect to the film $$\vec c$$ -axis. Beside an enlarged normal state resistivity after irradiation the films suffer a Tc-reduction proportional to the volume of the damaged material. The activation energy ascertained from resistive transitions shows best enhancement for magnetic field values close to the matching field. Measurements of the transport crit…
Relaxation of remnant magnetisation in YBa2Cu3O7−δ films
2007
Abstract The relaxation of the remnant magnetisation in optimally doped disk-shaped YBa2Cu3O7−δ films with the initially applied magnetic field H oriented along the c axis was measured using dc SQUID magnetometry. The temperature (T) dependence of the experimentally observed normalised magnetisation relaxation rate S exhibits three distinct regions. At high T, S(T) increases with increasing T, which can be explained in terms of plastic vortex creep. The well known plateau in the S(T) variation at intermediate T appears to be caused by collective (elastic) creep in a dynamically ordered vortex system. At low T, where S increases again with increasing T, the magnetisation relaxation is not in…
Impact of a cryogenic baffle system on the suppression of radon-induced background in the KATRIN Pre-Spectrometer
2018
The KATRIN experiment will determine the effective electron anti-neutrino mass with a sensitivity of 200 meV/c2 at 90% CL. The energy analysis of tritium β-decay electrons will be performed by a tandem setup of electrostatic retarding spectrometers which have to be operated at very low background levels of <10−2 counts per second. This benchmark rate can be exceeded by background processes resulting from the emanation of single 219,220Rn atoms from the inner spectrometer surface and an array of non-evaporable getter strips used as main vacuum pump. Here we report on the impact of a cryogenic technique to reduce this radon-induced background in electrostatic spectrometers. It is based on ins…
HAPEX-Sahel
1997
The variation in evaporative fraction and actual evaporation is examined for three sample days in the HAPEX-Sahel Intensive Observation Period (IOP), including data from all the vegetation types and sites. The trends in evaporative fraction over the IOP are also presented for eight sites. The high rate of evaporation from bare soil in the days following rainfall produces a variability in evaporation which makes differences between sites difficult to interpret on a day-to-day basis, but over the whole IOP it is shown that the millet uses a smaller proportion of the available energy for evaporation than the tiger bush or fallow savannah. The combined effect of differences in the total energy …
Testing two temporal upscaling schemes for the estimation of the time variability of the actual evapotranspiration
2015
Temporal availability of grapes actual evapotranspiration is an emerging issue since vineyards farms are more and more converted from rainfed to irrigated agricultural systems. The manuscript aims to verify the accuracy of the actual evapotranspiration retrieval coupling a single source energy balance approach and two different temporal upscaling schemes. The first scheme tests the temporal upscaling of the main input variables, namely the NDVI, albedo and LST; the second scheme tests the temporal upscaling of the energy balance output, the actual evapotranspiration. The temporal upscaling schemes were implemented on: i) airborne remote sensing data acquired monthly during a whole irrigatio…
Quantitative study of cardiac wall motion from cine-MRI using frequency-based optical flow methods
2010
The aim of this thesis is to study parietal desynchronisation of the left ventricle from conventional cine-MRI. The first part of our work consisted in the quantification of the left ventricle wall motion of the heart directly from conventional retrospective SSFP type cine-MRI sequences used in the study of cardiac function. The developed methods for measuring displacements within the images are frequency-based optical flow methods. These techniques seem to be particularly adapted to MRI specificities. We have demonstrated their robustness in the event of Rician noise and pixel intensity variations as a function of time. These variations are often associated with the through-plane motion of…
Tracing the origin of azimuthal gluon correlations in the color glass condensate
2016
We examine the origins of azimuthal correlations observed in high energy proton-nucleus collisions by considering the simple example of the scattering of uncorrelated partons off color fields in a large nucleus. We demonstrate how the physics of fluctuating color fields in the color glass condensate (CGC) effective theory generates these azimuthal multiparticle correlations and compute the corresponding Fourier coefficients v_n within different CGC approximation schemes. We discuss in detail the qualitative and quantitative differences between the different schemes. We will show how a recently introduced color field domain model that captures key features of the observed azimuthal correlati…
Azimuthal harmonics of color fields in a high energy nucleus
2015
Recent experimental results have revealed a surprisingly rich structure of multiparticle azimuthal correlations in high energy proton-nucleus collisions. Final state collective effects can be responsible for many of the observed effects, but it has recently been argued that a part of these correlations are present already in the wavefunctions of the colliding particles. We evaluate the momentum space 2-particle cumulant azimuthal anisotropy coefficients v_n{2}, n=2,3,4 from fundamental representation Wilson line distributions describing the high energy nucleus. These would correspond to the flow coefficients in very forward proton nucleus scattering. We find significant differences beteen W…
Influence of magnetic field on cooling by normal-insulator–superconductor junctions
2000
Cooling by normal-insulator–superconductor junctions in external magnetic field has been studied experimentally. For all orientations of magnetic field the cooling performance correlates with the magnetic field dependent superconducting energy gap Δ(H). In perpendicular orientation of magnetic field with respect to the sample plane, additional degradation of the cooling power originates from scattering of nonequilibrium quasiparticles in the superconductor on magnetic vortices. The effect is hysteretic and its magnitude depends on the shape of the superconducting probes.