Search results for "saturation"
showing 10 items of 478 documents
A comparison between simulation and experiment for hysteretic phenomena during two-phase immiscible displacement
2014
[1] The paper compares a theory for immiscible displacement based on distinguishing percolating and nonpercolating fluid parts with experimental observations from multistep outflow experiments. The theory was published in 2006 in Physica A, volume 371, pages 209–225; the experiments were published in 1991 in Water Resources Research, volume 27, pages 2113. The present paper focuses on hysteretic phenomena resulting from repeated cycling between drainage and imbibition processes in multistep pressure experiments. Taking into account, the hydraulic differences between percolating and nonpercolating fluid parts provides a physical basis to predict quantitatively the hysteretic phenomena observ…
Laser-induced field-free alignment of the OCS molecule
2007
We investigate the dynamical alignment of jet-cooled OCS molecules induced by a short laser pulse. The alignment is measured through the orientational contribution of the optical Kerr effect using a second weak laser pulse as a probe. Maximum alignment is observed at conditions close to saturation of ionization. The results are analysed with a quantum mechanical model solving for the rotational dynamics.
Dimensional analysis of pore scale and field scale immiscible displacement
1996
A basic re-examination of the traditional dimensional analysis of microscopic and macroscopic multiphase flow equations in porous media is presented. We introduce a ‘macroscopic capillary number’\(\overline {Ca}\) which differs from the usual microscopic capillary number Ca in that it depends on length scale, type of porous medium and saturation history. The macroscopic capillary number\(\overline {Ca}\) is defined as the ratio between the macroscopic viscous pressure drop and the macroscopic capillary pressure.\(\overline {Ca}\) can be related to the microscopic capillary number Ca and the LeverettJ-function. Previous dimensional analyses contain a tacit assumption which amounts to setting…
Next-to-leading order Balitsky-Kovchegov equation with resummation
2016
We solve the Balitsky-Kovchegov evolution equation at next-to-leading order accuracy including a resummation of large single and double transverse momentum logarithms to all orders. We numerically determine an optimal value for the constant under the large transverse momentum logarithm that enables including a maximal amount of the full NLO result in the resummation. When this value is used the contribution from the $\alpha_s^2$ terms without large logarithms is found to be small at large saturation scales and at small dipoles. Close to initial conditions relevant for phenomenological applications these fixed order corrections are shown to be numerically important.
Dijet azimuthal correlations and conditional yields in pp and p+Pb collisions at sNN=5.02TeV with the ATLAS detector
2019
This paper presents a measurement of forward-forward and forward-central dijet azimuthal angular correlations and conditional yields in proton-proton (pp) and proton-lead (p + Pb) collisions as a p ...
Electrophoretic mobility of charged spheres
2008
The electrophoretic mobility μ of charged 0.3 µm Polystyrene spheres suspended in water was measured over a wide range of salt concentrations c and packing fractions Φ. To observe isolated spheres at packing fractions Φ ≤ 2 × 10−7 a newly developed optical tweezing electrophoresis (OTE) apparatus was used. At deionised conditions μ=2.5 × 10−8 m2V−1s−1, it decreases further upon increasing the salt concentration c. Measurements at larger Φ generally show much larger μ and a qualitatively different dependence on c. At no added salt μ increases in the unordered state but a saturation at μ=6.8 × 10−8 m2V−1s−1 is observed, as the system develops fluid order. The fluid-crystal phase transition is…
Exploring the Physical Limits of Saturation Contrast in Magnetic Resonance Imaging
2012
International audience; Magnetic Resonance Imaging has become nowadays an indispensable tool with applications ranging from medicine to material science. However, so far the physical limits of the maximum achievable experimental contrast were unknown. We introduce an approach based on principles of optimal control theory to explore these physical limits, providing a benchmark for numerically optimized robust pulse sequences which can take into account experimental imperfections. This approach is demonstrated experimentally using a model system of two spatially separated liquids corresponding to blood in its oxygenated and deoxygenated forms.
Two-body contributions to the effective mass in nuclear effective interactions
2018
Starting from general expressions of well-chosen symmetric nuclear matter quantities derived for both zero- and finite-range effective theories, we derive the contributions to the effective mass. We first show that, independently of the range, the two-body contribution is enough to describe correctly the saturation mechanism but gives an effective mass value around $m^*/m \simeq 0.4$. Then, we show that the full interaction (by instance, an effective two-body density-dependent term on top of the pure two-body term) is needed to reach the accepted value $m^*/m \simeq 0.7-0.8$.
η′-Nucleus optical potential and possible η′ bound states
2012
Abstract Starting from a recent model of the η ′ N interaction, we evaluate the η ′ -nucleus optical potential, including the contribution of lowest order in density, t ρ / 2 m η ′ , together with the second-order terms accounting for η ′ absorption by two nucleons. We also calculate the formation cross section of the η ′ bound states from ( π + , p ) reactions on nuclei. The η ′ -nucleus potential suffers from uncertainties tied to the poorly known η ′ N interaction, which can be partially constrained by the experimental modulus of the η ′ N scattering length and/or the recently measured transparency ratios in η ′ nuclear photoproduction. Assuming an attractive interaction and taking the c…
Structure of the highly deformed nucleus101Sr63 and evidence for identical K=3/2 bands
1995
The low-energy level scheme of theN=63 nucleus101Sr has been obtained from a β-decay study of101Rb. The ν[532]5/2 and ν[411]3/2 orbitals are well established as the ground state and a band head at 271.2keV, respectively. The general properties of the level scheme indicate a quadrupole deformation ofβ ≃ 0.4, confirming the unique feature of saturation of deformation inN ≥ 60 Sr isotopes. The energies of theK=3/2 intraband transitions in the odd-neutron neighbours99Sr61 and101Sr63 are very similar. More generally, the identical bands at low spin in98–101Sr nuclei are correlated with the mass-independent moments of inertia in this region.