University of Marne-la-Vallée

About: University of Marne-la-Vallée is a based out in . It is known for research contribution in the topics: Estimator & Context (language use). The organization has 831 authors who have published 1855 publications receiving 55316 citations.

Interaction of Zn(II) with hematite nanoparticles and microparticles: Part 2. ATR-FTIR and EXAFS study of the aqueous Zn(II)/oxalate/hematite ternary system.

Abstract: Sorption of Zn(II) to hematite nanoparticles (HN) (av diam = 10.5 nm) and microparticles (HM) (av diam = 550 nm) was studied in the presence of oxalate anions (Ox 2― (aq) ) in aqueous solutions as a function of total Zn(II) (aq) to total Ox 2― (aq) ) concentration ratio (R = [Zn(II) (aq) ] tot /[Ox 2― (aq) ] tot ) at pH 5.5. Zn(II) uptake is similar in extent for both the Zn(II)/Ox/HN and Zn(II)/Ox/HM ternary systems and the Zn(II)/HN binary system at [Zn(II) (aq) ] tot 4 mM. In contrast, Zn(II) uptake for the Zn(II)/HM binary system is a factor of 2 greater than that for the Zn(II)/Ox/HM and Zn(II)/Ox/HN ternary systems and the Zn(II)/HN binary system at [Zn(II) (aq) ] tot O 2 ―Zn― Ox) are present. In the Zn(II)/Ox/HN ternary system at R = 0.15, ATR-FTIR results indicate the presence of inner-sphere oxalate and outer-sphere ZnOx (aq) complexes; the EXAFS results provide no evidence for inner-sphere Zn(II) complexes or type A ternary complexes. In contrast, ATR-FTIR results for the Zn/Ox/HN sample with R = 0.68 are consistent with a ZnOx (s) -like surface precipitate and possibly type B ternary surface complexes (i.e., > O 2 ―Ox―Zn). EXAFS results are also consistent with the presence of ZnOx (s) -like precipitates. We ascribe the observed increase of Zn (II) (aq) uptake in the Zn(II)/Ox/HN ternary system at [Zn(II) (aq) ] tot ≥ 4 mM relative to the Zn(II)/Ox/HM ternary system to formation of a ZnOx (s) -like precipitate at the hematite nanoparticle/water interface.

The determinants of growth for SMEs. A longitudinal study of French manufacturing firms

Abstract: This paper investigates the structural and strategic determinants of firmgrowth using a unique data set covering French firms with between 10 and 250employees and active from 1997 through 2007. On the basis of the propositionthat Gibrat’s Law does not hold in this case, we consider a growth model thatcombines different factors that may be determinants of the firm’s growth path.The results, which are based on two families of multinomial logit models, confirmthat firm growth is not only a random process. Instead, size, legal structure,market share and localization are found to have a significant impact on thedevelopment of the individual growth path. These environmental and structuralelements are not the only elements on which to focus when attempting to explainemployment growth on the firm level - strategic factors matter as well. In thisregard, we demonstrate the critical role of labor costs and financial structure asexplanatory variables in firm growth.Keywords: Firm growth, SMEs, Gibrat’s law, French manufacturing, multi-nomial logistic regression.JEL Codes: L25, C51, D22.

An explicit formula for the characters of the symmetric group

Abstract: We give an explicit expression of the normalized characters of the symmetric group in terms of the contents of the partition labelling the representation.

Probabilistic modeling of a nonlinear dynamical system used for producing voice

Abstract: This paper is devoted to the construction of a stochastic nonlinear dynamical system for signal generation such as the production of voiced sounds. The dynamical system is highly nonlinear, and the output signal generated is very sensitive to a few parameters of the system. In the context of the production of voiced sounds the measurements have a significant variability. We then propose a statistical treatment of the experiments and we developed a probability model of the sensitive parameters in order that the stochastic dynamical system has the capability to predict the experiments in the probability distribution sense. The computational nonlinear dynamical system is presented, the Maximum Entropy Principle is used to construct the probability model and an experimental validation is shown.