Search results for "EQUILIBRIA"
showing 10 items of 39 documents
Formation of Coherent Structures in Kolmogorov Flow with Stratification and Drag
2014
We study a weakly stratified Kolmogorov flow under the effect of a small linear drag. We perform a linear stability analysis of the basic state. We construct the finite dimensional dynamical system deriving from the truncated Fourier mode approximation. Using the Reynolds number as bifurcation parameter we build the corresponding diagram up to Re=100. We observe the coexistence of three coherent structures.
Transitions in a stratified Kolmogorov flow
2016
We study the Kolmogorov flow with weak stratification. We consider a stabilizing uniform temperature gradient and examine the transitions leading the flow to chaotic states. By solving the equations numerically we construct the bifurcation diagram describing how the Kolmogorov flow, through a sequence of transitions, passes from its laminar solution toward weakly chaotic states. We consider the case when the Richardson number (measure of the intensity of the temperature gradient) is $$Ri=10^{-5}$$ , and restrict our analysis to the range $$0<Re<30$$ . The effect of the stabilizing temperature is to shift bifurcation points and to reduce the region of existence of stable drifting states. The…
(Liquid + liquid) equilibria of polymer-salt aqueous two-phase systems for laccase partitioning : UCON 50-HB-5100 with potassium citrate and (sodium …
2012
Aqueous two-phase systems (ATPS) are recognized as very suitable techniques for the recovery of target solutes in biological applications. Three new phase diagrams of (UCON 50-HB-5100 + potassium citrate + water), (UCON 50-HB-5100 + sodium formate + water), and (UCON 50-HB-5100 + potassium formate + water) systems were measured at 23 C. The binodal curves were successfully described using the empirical equation suggested by Merchuk and co-workers. The reliability of the tie-line data experimentally determined was evaluated using the equations reported by Othmer–Tobias and Bancroft and satisfactory linearity was obtained for all ATPS. Among the salts studied, potassium citrate proved to be t…
Pre-Eruptive Conditions of La Sommata Basalt (Vulcano, Aeolian Islands): Constraints from Experimental Petrology.
2011
One of the most primitive magma of Aeolian Arc is the basalt erupted (about 50 ka B.P.) by the La Sommata scoria cone at Vulcano; this is a silica-undersaturated (ne-normative) low-phyric (10-20 wt. %), Ca-rich (CaO = 13 wt. %) shoshonitic basalt (K2O = 2.28 wt.%) in which olivine phenocrysts host melt inclusions more primitive than whole rock composition and with an ultra-calcic character: CaO/Al2O3 > 1.4 [Métrich and Clocchiatti, 1996; Gioncada et al., 1998; Schiano et al., 2000]. Phenocrysts mainly include olivines (Fo92) and clinopyroxenes (Fs5). Plagioclase microlites (from An79 to An67) are the most abundant groundmass phase (45 wt. %), together with clinopyroxene (Fs11) and olivine (…
Influence of hydrogen cations on kinetics and equilibria of heavy-metal sorption by algae-sorption of copper cations by the alga
2012
The influence of hydrogen cations on kinetics and equilibria of sorption of copper cations by the marine alga Palmaria palmata (Linnaeus) Weber & Mohr was studied under static conditions. The competitive effect of the H+ cations is described, which influenced the uncertainty of evaluation of the alga sorption capacity. Under static conditions, the variation of the Cu2+/H+ concentration ratio during sorption was found nonmonotonic. The Langmuir isotherm model was used to determine the sorption capacity of the alga, namely 12.4 mg g−1 of dry algae mass. A similar value was determined from the kinetic parameters of the ionic exchange which is considered a pseudo-second-order chemical reaction.…
Entry with two correlated signals : the case of industrial espionage and its positive competitive effects
2021
Recent advances in information and communication technologies have increased the incentives for firms to acquire information about rivals. These advances may have major implications for market entry because they make it easier for potential entrants to gather valuable information about, for example, an incumbent’s cost structure. However, little theoretical research has actually analyzed this question. This paper advances the literature by extending a one-sided asymmetric information version of Milgrom and Roberts’ (1982) limit pricing model. Here, the entrant is allowed access to an intelligence system (IS) of a certain precision that generates a noisy signal on the incumbent’s cost struct…
Evaluating currency crises: the case of the European monetary system
2007
In this paper we examine the nature of currency crises. We ascertain whether the currency crises of the European Monetary System (EMS) were based either on fundamentals, or on self-fulfilling market expectations driven by extrinsic uncertainty. In particular, we extend previous work of Jeanne and Masson (J Int Econ 50:327–350, 2000) regarding the evaluation of currency crisis. We contribute to the existing literature proposing the use of Markov regime-switching with time-varying transition probability model. Our empirical results suggest that the currency crises of the EMS were not due only to market expectations driven by external uncertainty, or ‘sunspots’, but also to fundamental variabl…
NASH EQUILIBRIA IN A MODEL OF MULTIPRODUCT PRICE COMPETITION: AN ASSIGNMENT PROBLEM
2003
We study the market interaction of a finite number of single-product firms and a representative buyer, where the buyer consumes bundles of these goods. The buyers' value function determines their willingness to pay for subsets of goods. We show that subgame perfect Nash-equilibrium outcomes are solutions of the linear relaxation of an integer programming assignment problem and that they always exits. The (subgame perfect) Nash-equilibrium price set is characterized by the Pareto frontier of the associated dual problem's projection on the firms' price vectors. We identify the Nash-equilibrium prices for monotonic buyers' value functions and, more importantly, we show that some central soluti…
The Formal Redox Potential of the Ti(IV, III) Couple at 25 °C in 1 M HCl 2 M NaCl Medium
2007
The formal redox potential of the Ti(IV, III) couple has been determined at 25 degrees C in 1 M HCl, 2 M NaCl aqueous medium, by emf measurements of a junction-free cell with glass and mercury electrodes. Ti(III) and Ti(IV) concentrations were changed by controlled electrolysis. The mean value of the searched formal potential, in a large range of total titanium concentration, is 9 +/- 1 mV against the molar hydrogen electrode in the same ionic medium.
Liquid–Liquid Equilibria of Water + Ethanol + 1-Butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide Ternary System: Measurements and Correla…
2015
In this work authors present the experimental liquid–liquid equilibria (LLE) data of water + ethanol + 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([bmim][Tf2N]) system at different temperatures. The LLE of the system was obtained in the temperature range from 283.2 to 323.2 K. The nonrandom two liquid (NRTL) and universal quasichemical (UNIQUAC) models were used to correlate ternary systems. The equilibrium compositions were successfully correlated by the interaction parameters from both models, however UNIQUAC gave a more accurate correlation. Finally, a study about the solvent capability of ionic liquid was made in order to evaluate the possibility of separating the mi…