Search results for "COEFFICIENTS"
showing 10 items of 108 documents
The beta-, neutrino- and proton-asymmetry in neutron beta-decay
2004
This article describes measurements of angular-correlation coefficients in the decay of free neutrons with the superconducting spectrometer PERKEO II. A method for measuring the β-asymmetry coefficient A is presented, as well as a new method for determining the neutrino-asymmetry coefficient B, which allows a value for the proton-asymmetry coefficient C to be obtained for the first time. An ongoing experiment is trying to improve the accuracy of these quantities.
Memory expansion for diffusion coefficients
1998
We present a memory expansion for macroscopic transport coefficients such as the collective and tracer diffusion coefficients ${D}_{C}$ and ${D}_{T},$ respectively. The successive terms in this expansion for ${D}_{C}$ describe rapidly decaying memory effects of the center-of-mass motion, leading to fast convergence when evaluated numerically. For ${D}_{T},$ one obtains an expansion of similar form that contains terms describing memory effects in single-particle motion. As an example we evaluate ${D}_{C}$ and ${D}_{T}$ for three strongly interacting surface systems through Monte Carlo simulations, and for a simple model diffusion system via molecular dynamics calculations. We show that the n…
Thermodynamics of Proton Binding of Halloysite Nanotubes
2016
In this paper, new information on physical and chemical properties of the widely used nanostructured Halloysite mineral are reported. Given that the Halloysite has a tubular structure formed by a variable number of wrapped layers containing Si-OH and Al-OH groups, their proton binding affinity was measured at different ionic strengths and ionic media by means of potentiometric measurements in heterogeneous phase. One protonation constant for the Si-OH groups and two for the Al-OH groups were determined. The protonation constant values increase with increasing of the ionic strength in all the ionic media. This suggests that the presence of a background electrolyte stabilizes the protonated s…
Fractional integration, differentiation, and weighted Bergman spaces
1999
We study the action of fractional differentiation and integration on weighted Bergman spaces and also the Taylor coeffficients of functions in certain subclasses of these spaces. We then derive several criteria for the multipliers between such spaces, complementing and extending various recent results. Univalent Bergman functions are also considered.
On the Cauchy problem for microlocally symmetrizable hyperbolic systems with log-Lipschitz coefficients
2017
International audience; The present paper concerns the well-posedness of the Cauchy problem for microlocally symmetrizable hyperbolic systems whose coefficients and symmetrizer are log-Lipschitz continuous, uniformly in time and space variables. For the global in space problem we establish energy estimates with finite loss of derivatives, which is linearly increasing in time. This implies well-posedness in H ∞ , if the coefficients enjoy enough smoothness in x. From this result, by standard arguments (i.e. extension and convexification) we deduce also local existence and uniqueness. A huge part of the analysis is devoted to give an appropriate sense to the Cauchy problem, which is not evide…
Biopartitioning micellar chromatoraphy to predict blood to lung, blood to liver, blood to fat and blood to skin partition coefficients of drugs
2009
[EN] Biopartitioning micellar chromatography (BMC), a mode of micellar liquid chromatography that uses micellar mobile phases of Brij35 in adequate experimental conditions, has demonstrated to be useful in mimicking the drug partitioning process into biological systems. In this paper, the usefulness of BMC for predicting the partition coefficients from blood to lung, blood to liver. blood to fat and blood to skin is demonstrated. PLS2 and multiple linear regression (MLR) models based on BMC retention data are proposed and compared with other ones reported in bibliography. The proposed models present better or similar descriptive and predictive capability. (C) 2008 Elsevier B.V. All rights r…
The decay of 133mXe.
2007
The decay of (133m)Xe has been re-measured using an electron-transporter spectrometer and a planar HPGe detector. The sample of (133m)Xe was produced by means of proton-induced fission using an ion-guide based on-line mass separator. The deduced K and L+M+... shell conversion coefficients, alpha(Kappa)=6.5(9) and alpha(L+M+...)=2.9(4), agree within the uncertainty limits with the theoretical values and remove the inconsistencies between the previous experimental studies of (133m)Xe.
Internal spring distribution for quasi brittle fracture via Symmetric Boundary Element Method
2009
Abstract In this paper the symmetric boundary element formulation is applied to the fracture mechanics problems for quasi brittle materials . The basic aim of the present work is the development and implementation of two discrete cohesive zone models using Symmetric Galerkin multi-zone Boundary Elements Method . The non-linearity at the process zone of the crack will be simulated through a discrete distribution of nodal springs whose generalized (or weighted) stiffnesses are obtainable by the cohesive forces and relative displacements modelling. This goal is reached coherently with the constitutive relation σ − Δ u that describes the interaction between mechanical and kinematical quantities…
A correction method for dynamic analysis of linear continuous systems
2005
A method to improve the dynamic response analysis of continuous classically damped linear system is proposed. As in fact usually, following a classical approach, a reduced number of eigenfunctions are accounted for and the response is evaluated by integrating the uncoupled differential equations of motion in modal space, neglecting the contribution of high frequency modes (truncation procedure). Here, starting from the given system, it is proposed to set up two differential equations governing the motion of two new continuous systems: the first one contains only the first m non-zero eigenvalues of the given system and the second one contains the remainder non-zero infinity - m eigenvalues. …
Characterization of wastewater and biomass activity in a membrane bioreactor using respirometric techniques
2010
Over the last two decades, Membrane Bioreactors (MBRs) emerged even more for wastewater treatment, ensuring high removal efficiencies as well as very small footprint required. Indeed, in this kind of process, a modification in biomass activity and viability can exist compared to that of a conventional activated sludge (CAS) process. In this context, respirometric analysis represents a reliable tool in order to evaluate the actual biomass kinetic parameters, to insert in mathematical models in the design phase, as well as to monitor the biomass viability, especially when these processes are operated with high sludge retention time (SRT) values. The paper presents some results of respirometri…