When a drop of a viscous fluid is deposited on a bath of the same fluid, it is shown that its coalescence with this substrate is inhibited if the system oscillates vertically. Small drops lift off when the peak acceleration of the surface is larger than g. This leads to a steady regime where a drop can be kept bouncing for any length of time. It is possible to inject more fluid into the drop to increase its diameter up to several centimeters. Such a drop remains at the surface, forming a large sunk hemisphere. When the oscillation is stopped, the two fluids remain separated by a very thin air film, which drains very slowly (approximately 30 min). An analysis using lubrication theory accounts for most of the observations.
The coefficients of different combinations of terms of the liquid drop model have been determined by a least square fitting procedure to the experimental atomic masses. The nuclear masses can also be reproduced using a Coulomb radius taking into account the increase of the ratio R0/A 1/3 with increasing mass, the fitted surface energy coefficient remaining around 18 MeV.PACS numbers: 21.10. Dr; 21.60.Ev; 21.60.Cs To predict the stability of new nuclides both in the superheavy element region and the regions close to the proton and neutron drip lines continuous efforts are still needed to determine the nuclear masses and therefore the binding energies of such exotic nuclei. Within a modelling of the nucleus by a charged liquid drop, semimacroscopic models including a pairing energy have been firstly developed to reproduce the experimental nuclear masses [1,2]. The coefficients of the Bethe-Weizsäcker mass formula have been determined once again recently [3]. To reproduce the non-smooth behaviour of the masses (due to the magic number proximity, parity of the proton and neutron numbers,...) and other microscopic properties, macroscopic-microscopic approaches have been formulated, mainly the finite-range liquid drop model and the finite-range droplet model [4]. Nuclear masses have also been obtained accurately within the statistical Thomas-Fermi model with a well-chosen effective interaction [5,6]. Microscopic Hartree-Fock selfconsistent calculations using mean-fields and Skyrme or Gogny forces and pairing correlations [7,8] as well as relativistic mean field theories [9] have also been developed to describe these nuclear masses. Finally, nuclear mass systematics using neural networks have been undertaken recently [10].The nuclear binding energy B nucl (A,Z) which is the energy necessary for separating all the nucleons constituting a nucleus is connected to the nuclear mass M n.m byThis quantity may thus be easily derived from the experimental atomic masses as published in [11] since : MeV. The fission, fusion, cluster and α decay potential barriers are governed by the evolution of the nuclear binding energy with deformation. It has been shown that four basic terms are sufficient to describe the main features of these barriers [13,14,15,16,17,18] : the volume, surface, Coulomb and nuclear proximity energy terms while the introduction of the shell and pairing energy terms is needed to explain structure effects and improve quantitatively the results. Other terms have been proposed to determine accurately the binding energy and other nuclear characteristics : the curvature, A 0 , proton form factor correction, Wigner, Coulomb exchange correction,...energy terms [4].The purpose of the present work is to determine the coefficients of different combinations of terms of the liquid drop model by a least square fitting procedure to the experimentally available atomic masses [11] and to study whether nuclear masses can also be reproduced using, for the Coulomb energy, a radius which takes into account the small decrease of...
[1] The performance of the spectral wind wave model SWAN in tidal inlet seas was assessed on the basis of extensive wave measurements conducted in the Amelander Zeegat tidal inlet and the Dutch Eastern Wadden Sea, as well as relevant data from other inlets, lakes, estuaries and beaches. We found that the 2006 default SWAN model (version 40.51), the starting point of the investigation, performed reasonably well for measured storm conditions, but three aspects required further attention. First, over the near-horizontal tidal flats, the computed ratio of integral wave height over water depth showed an apparent upper limit using the default depth-limited wave breaking formulation and breaker parameter, resulting in an underprediction of wave heights. This problem has been largely solved using a new breaker formulation. The second aspect concerns wave-current interaction, specifically the wave age effect on waves generated in ambient current, and a proposed enhanced dissipation in negative current gradients. Third, the variance density of lower-frequency wind waves from the North Sea penetrating through the inlets into the Wadden Sea was underpredicted. This was improved by reducing the bottom friction dissipation relative to that of the default model. After a combined calibration, these improvements have resulted in a relative bias reduction in H m0 from À3% to À1%, in T mÀ1,0 from À7% to À3%, and in T m01 from À6% to À2%, and consistent reductions in scatter, compared to the 2006 default model.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.