Dual Equilibrium Research Articles

Feasibility of treating aged polycyclic aromatic hydrocarbons (PAHs)-contaminated soils using ethyl lactate-based Fenton treatment via parametric and kinetic studies.

This study focuses on the feasibility of treating aged polycyclic aromatic hydrocarbons (PAHs)-contaminated soils using ethyl lactate (EL)-based Fenton treatment via a combination of parametric and kinetic studies. An optimised operating condition was observed at 66.7 M H2O2 with H2O2/Fe(2+) of 40:1 for low soil organic carbon (SOC) content and mildly acidic soil (pH 6.2), and 10:1 for high SOC and very acidic soil (pH 4.4) with no soil pH adjustment. The desorption kinetic was only mildly shifted from single equilibrium to dual equilibrium of the first-order kinetic model upon ageing. Pretreatment with EL fc = 0.60 greatly reduced the mass transfer coefficient especially for the slow desorbed fraction (kslow) of high molecular weight (HMW) PAHs, largely contributed by the concentration gradient created by EL-enhanced solubility. As the major desorption obstacle was almost fully overcome by the pretreatment, the pseudo-first-order kinetic reaction rate constant of PAHs degradation of aged soils was statistically discernible from that of freshly contaminated soils but slightly reduced in high SOC and high acidity soil. Stabilisation of H2O2 by EL addition in combination with reduced Fe(2+) catalyst were able to slow the decomposition rate of H2O2 even at higher soil pH.

Experimental Investigation on the Solubility of Oxygen in Toluene and Acetic Acid

By using the dual vessel equilibrium method, the solubility of oxygen in toluene and acetic acid was experimentally investigated with pressure ranging from 0.1 to 1.0 MPa at temperatures from 293.1 to 383.1 K. The results show that the oxygen solubility either in toluene or in acetic acid increases with a rise in temperature. On the basis of the experimental data, Henry coefficients were derived and expressed as a function of temperature. At the same temperature, Henry coefficient for the oxygen–toluene system is lower than that for the oxygen–acetic acid system. Through analysis of the Gibbs energy (ΔG0), partial molar enthalpy (ΔH0), and the partial molar entropy (ΔS0) of the solvation, we can know that solubilization of oxygen either in toluene or in acetic acid is an endothermic process. To correlate the experimental data, the Peng–Robinson equation of state with the quadratic mixing rule was used for the two systems.

A model for coupling fire and insect outbreak in forests

Predictive models of insect outbreak exist for some processes for few species, but an additional and rarely explored complication is the potential interaction between insect outbreak and wildfire disturbances in forests. The association between insect and fire dynamics is complex, particularly when evaluated over time and at large scale, and no consensus exists in the published literature about its consequences. Thus, more insights on the issue would be useful to scientists, resource managers, and the public when making decisions on, to name a few, firefighting, operations and treatments to reduce wildfire/insect impacts. In this article we propose mathematical models incorporating the effect of insect outbreaks either as a single disturbance in the forest population dynamics or coupled with wildfire disturbances. For the beetle-tree system model analytical and numerical characterization of its temporal dynamics shows that the system exhibits the well known beetle-tree interaction described by the dual equilibrium theory. For the extended model that includes fire, numerical simulations demonstrate the potential for existence of positive feedback between wildfire and insect outbreak disturbances in certain region of fire strength. This result agrees with one of the current theories in the field.

Incentives and Matching of Heterogeneous Principals and Agents: Field Evidence from a Mutual Fund Scandal

The mutual fund industry consists of heterogeneous managers and investors. Hence, traditional models of delegated portfolio management need to be extended to allow heterogeneity. We propose that this extension can be modeled as a dual matching-contracting problem of endogenously repeated trust games, and demonstrate that dual matching and contracting efficiency can be achieved in an equilibrium in which more risk tolerant funds are matched with investors more inert to negative information and in which all managers exert effort. Empirical tests based on the investigation of mutual fund scandal in 2003 are largely consistent with the dual efficiency equilibrium.

A Cooperative Dual to the Nash Equilibrium for Two-Person Prescriptive Games

An alternative to the Nash equilibrium (NE) is presented for two-person, one-shot prescriptive games in normal form, where the outcome is determined by an arbiter. The NE is the fundamental solution concept in noncooperative game theory. It is based on the assumption that players are completely selfish. However, NEs are often not played in practice, so we present a cooperative dual as an alternative solution concept by which an arbiter can assign the players' actions. In this dual equilibrium (DE), each player acts in the other's best interest. We formally define prescriptive games and the DE, then summarize the duality relationships between the NE and DE for two players. We also apply the DE to some prescriptive games and compare it to other outcomes.

Onη-Upper Sign Property and Upper Sign Continuity and Their Applications in Equilibrium-Like Problems

We first introduce the notion ofη-upper sign property which is an extension of the upper sign property introduced in Castellani and Giuli, 2013, by relaxing convexity on the set. Afterwards, we establish a link between the solution sets of local dual equilibrium problem (Minty local equilibrium problem) and equilibrium problem for mappings whose domains are not necessarily convex by relaxing the upper sign continuity on the map, as it is assumed in the literature (Bianchi and Pini, 2005; Castellani and Giuli, 2013; Farajzadeh and Zafarani, 2010). Accordingly, it allows us to extend and obtain some existence results for equilibrium-like problems.

Political Economy of Labour Market Segmentation: Agency Work in the Automotive Industry

This paper investigates cross-company variation in the core-periphery configuration of the workforce. The empirical focus is on four automotive plants in Germany, which differ in terms of their organisation of agency work. The comparison reveals that there is no automatic relationship between skills, products and company workforce structure. As traditional employer-driven explanations such as production requirements and skills fail to make sense of the variations encountered, the main argument of the paper is based on the power-resource approach. More specifically, the strategy devised by works councils in relation to managerial imperatives has a major role in shaping employment and the core-periphery configuration in the subsidiaries. The key power resources that condition the strategy adopted by worker representatives are constituted also beyond the workplace, insofar as the plant’s socio-economic context – including factors such as the local unemployment rate, or the threat of outsourcing and labour market deregulation – matters as much as the company-level industrial relations. The paper thus challenges the interpretation of segmented labour markets as a dual efficient equilibrium and points out the political and contested nature of segmentation. The empirical evidence presented here has a wider significance as practices in German automotive MNC, characterized by Europe-wide production networks, are likely to affect a large number of workers across Europe.

Predicting the syngas hydrogen composition by using a dual stage equilibrium model

This paper presents an analysis of hydrogen syngas composition obtained by biomass gasification when simulated by a dual stage equilibrium model. The numerical model takes advantage of the carbon boundary point (CBP) concept to study the hydrogen production at maximum energetic and exergetic efficiencies. The numerical simulation was carried out using three large biomass residues available in Portugal: coffee husks, pine residues and vine pruning wastes. It was concluded that the three biomass substrates showed similar trends at different operating conditions and the vine pruning wastes showed the best hydrogen outputs. The computed results were also compared with pilot scale experimental data obtained for coffee husk residues. The numerical results differ from experimental data, but in both cases the hydrogen composition has similar changes taking into consideration the effect of different operating conditions. It was concluded that the hydrogen molar composition increases steeply with a steam to biomass ratio (SBR) below the CBP and with a slow rate above the CBP, up to an asymptotic value. Similar behavior was found considering the temperature effect on hydrogen production. It was also found that energy efficiency first increases with the SBR up to a maximum value and then decreases.

Droplets on liquid surfaces: Dual equilibrium states and their energy barrier

Floating aqueous droplets were formed at oil-air interface, and two stable configurations of (i) non-coalescent droplet and (ii) cap/bead droplet were observed. General solutions for energy and force analysis were obtained for both configurations and were shown to be in good agreement with the experimental observations. The energy barrier obtained for transition from configuration (i) to configuration (ii) was correlated to the droplet release height and the probability of non-coalescent droplet formation.

Reducing price of anarchy of selfish task allocation with more selfishness

In this paper we consider the task allocation problem from a new game theoretic perspective. We assume that tasks and machines are both controlled by selfish agents with two distinct objectives, which stands in contrast to the passive role of machines in the traditional model of selfish task allocation. To characterize the outcome of this new game where two classes of players interact, we introduce the concept of dual equilibrium. We prove that the price of anarchy with respect to dual equilibria is 1.4, which is considerably smaller than the counterpart 2 in the traditional model. Our study shows that activating more freedom and selfishness in a game may bring about a better global outcome.

Simulation of steady-state diffusion: Driving force ensured by dual control volumes or local equilibrium Monte Carlo

We provide a systematic comparative analysis of various simulation methods for studying steady-state diffusive transport of molecular systems. The methods differ in two respects: (1) the actual method with which the dynamics of the system is handled can be a direct simulation technique [molecular dynamics (MD) and dynamic Monte Carlo (DMC)] or can be an indirect transport equation [the Nernst-Planck (NP) equation], while (2) the driving force of the steady-state transport can be maintained with control cells on the two sides of the transport region [dual control volume (DCV) technique] or it can be maintained in the whole simulation domain with the local equilibrium Monte Carlo (LEMC) technique, where the space is divided into small subvolumes, different chemical potentials are assigned to each, and grand canonical Monte Carlo simulations are performed for them separately. The various combinations of the transport-methods with the driving-force methods have advantages and disadvantages. The MD+DCV and DMC+DCV methods are widely used to study membrane transport. The LEMC method has been introduced with the NP+LEMC technique, which was proved to be a fast, but somewhat empirical method to study diffusion [D. Boda and D. Gillespie, J. Chem. Theor. Comput. 8, 824 (2012)]. In this paper, we introduce the DMC+LEMC method and show that the resulting DMC+LEMC technique has the advantage over the DMC+DCV method that it provides better sampling for the flux, while it has the advantage over the NP+LEMC method that it simulates dynamics directly instead of hiding it in an external adjustable parameter, the diffusion coefficient. The information gained from the DMC+LEMC simulation can be used to construct diffusion coefficient profiles for the NP+LEMC calculations, so a simultaneous application of the two methods is advantageous.

The Simple Analytics of Sudden Stops

Currency crises in emerging and developing countries have often been characterized by “sudden stops” of capital flows. A variety of mechanisms have been adduced to explain the emergence of this phenomenon. This paper integrates these mechanisms into a simple and transparent analytical model in which currency mismatches, large current account deficits, and large stocks of short-term debt interact with low reserve stocks to generate dual equilibria. In this context, the “panic” equilibrium is characterized by a currency crisis, a sudden stop, and an output collapse. The potential for various policies to avoid this outcome is explored, as are the implications of the analysis for reserve accumulation.

On dual vector equilibrium problems

In this work, we consider the dual vector equilibrium problems in the topological vector spaces setting for a moving cone. We investigate the relationship between solutions of the vector equilibrium problems and those for their perturbations. Our result may be viewed as a refinement and improvement of the paper [L. Huang, Existence of Solutions on Weak Vector Equilibrium Problems, vol. 65, 2006, pp. 795–801.].

Side Constrained Traffic Assignment Model Based on Network Dual Equilibrium

One side constrained traffic assignment model is presented based on the local nearsighted user equilibrium principle by taking advantage of network dual equilibrium theorem. The traffic flow and travel time are regarded as a pair of dual variables. The analysis is started from the basic elements of network. At first, the dual relationships between the conservation conditions of node's flow and the shortest travel time from origin to the node are considered. Then the dual relationships between link flow and travel time constrains on link with nearsighted users are also analyzed. At last, through combining these dual relationships and adding generalized side constraints, new traffic assignment model is built. How to embody two behavioral assumptions (priority of playing cards and elasticity of route adjusting on route) in the proposed algorithm to the model is analyzed. A searching method of effective path set is given by using the model's solution results of unique link flow with respect to origin and destination pair. Several numeral examples are given to prove the validity and efficiency of the model and related algorithm. The results for the side constrained model are explained by congestion pricing and queue delay on links.

Dual equilibrium and growth cycle in Argentina

Argentina’s GDP growth cycle, tracing the high exchange rate volatility in 1970–2008, is discussed. Growth depends on foreign exchange availability. The country’s comparative advantage is in agriculture, but manufactured exports are grow faster. Two remarkably different PPP exchange rates coexist – one appropriate for agriculture and one for manufacturing – destabilising the market exchange rate. Thus, two unstable growth equilibria coexist generating GDP fluctuations. Currency devaluation sets the cycle’s ceiling and the end of devaluation sets the cycle’s floor. Chronic government deficits widen the cycle, harming institutions and decelerating growth. A land tax to finance rural investment would facilitate a high and stable exchange rate (AR$/US$) and convergence to the high growth equilibrium.

Hollow current profile scenarios for advanced tokamak reactor operations

Advanced tokamak scenarios are a possible approach to boosting reactor performances. Such schemes usually trigger current holes, a particular magnetohydrodynamics equilibrium where no current or pressure gradients exist in the core of the plasma. While such equilibria have large bootstrap fractions, flat pressure profiles in the plasma core may not be optimal for a reactor. However, moderate modifications of the equilibrium current profile can lead to diamagnetism where most of the pressure gradient is now balanced by poloidal currents and the toroidal magnetic field. In this paper, we consider the properties of diamagnetic current holes, also called “dual equilibria,” and demonstrate that fusion throughput can be significantly increased in such scenarios. Their stability is investigated using the DCON code. Plasmas with a beta peak of 30% and an average beta of 6% are found stable to both fixed and free-boundary modes with toroidal mode numbers n=1–4, as well as Mercier and high-n ballooning modes. This is not surprising as these scenarios have a normal beta close to 3.

A method of duality for a mixed vector equilibrium problem

In this paper, a dual scheme for a mixed vector equilibrium problem is introduced by using the method of Fenchel conjugate function. Under the stabilization condition, the relationships between the solutions of mixed vector equilibrium problem (MVEP) and dual mixed vector equilibrium problem (DMVEP) are discussed. Moreover, under the same condition, the solutions of MVEP and DMVEP are proved relating to the saddle points of an associated Lagrangian mapping. As applications, this dual scheme is applied to vector convex optimization and vector variational inequality.

Interaction of malathion, an organophosphorus pesticide with Rhizopus oryzae biomass

Adsorption of malathion on Rhizopus oryzae biomass (ROB) with special reference to binding mechanism has been described. ROB has been found to adsorb approximately 85% of malathion from its aqueous solution as against 47-68% by other fungal biomasses. Hydrogen ion concentration does not influence the adsorption of malathion by ROB which follows Langmuir-Freundlich dual equilibrium isotherm model (r(2)=0.998). Both physical and chemical interactions are responsible for binding of malathion on ROB. Scanning electron micrographs and EDXA spectra exhibit adsorption of the pesticide on cell surface of ROB. Studies with cell surface polysaccharides show that chitosan through its amine groups contributes largely in the adsorption of malathion. Extraction of lipids from ROB decreases its adsorption capacity to the extent of 36.37-94.02%, depending on the polarity of the solvent.

Spacecraft coordination control in 6DOF: Integrator backstepping vs passivity-based control

In this paper, we present three nonlinear control solutions for 6DOF spacecraft formation control, adopted from Euler–Lagrange system theory. The quaternion parametrization results in dual equilibrium points in the closed loop system, and the controllers are proved to render these uniformly asymptotically stable. We also present a theoretical comparison of the three control solutions, together with simulation results to visualize the performance of the controllers.

Kinetic and Thermodynamic Characterization of Telomeric G-Quadruplex by Nonequilibrium Capillary Electrophoresis: Application to G-Quadruplex/Duplex Competition

In this paper, nonequilibrium capillary electrophoresis (NECE) was attempted for the first time to investigate a dual equilibrium system, where the intramolecular G-quadruplex folding was in competition with the intermolecular duplex formation. Samples of an equilibrium mixture of human telomeric DNA and its complementary strands were separated in capillaries under nonequilibrium conditions without K (+). Polyethylene oxide was added to the running buffer facilitating the separation of single-stranded DNA, duplex, and G-quadruplex. Thus, the folding/unfolding rate constants of the G-quadruplex and the association/dissociation constants of the duplex could be simultaneously derived from the same experiment. Results indicated that the duplex formation induced minimal influence on the G-quadruplex folding. On the basis of the kinetic characterization of the G-quadruplex at varying temperatures, the thermodynamic parameters of the G-quadruplex could also be determined. Thus, the NECE method provided a new avenue for studying the kinetics and thermodynamics of nucleic acids within dual equilibrium systems with significant advantages of extreme-low sample cost (approximately 10 (-18) mol) and high repeatability.