Equilibrium Rate Research Articles

Finite element simulation of a motorway bridge collapse using the concrete damage plasticity model

The aim of this work is to show how the concrete damage plasticity model developed by Lubliner et al. can be applied for calculation of a motorway bridge collapse occurred in the Amur region, Russia. The concrete structural behaviour is highly complex. Being a quasi-brittle material, concrete demonstrates softening behaviour that is numerically complex due to the loss of positive definiteness of the tangent rigidity matrix of the material, and hence the loss of the ellipticity of the equilibrium rate equation. This eventually leads to the loss of well-posedness of the rate boundary value problem. Besides that, concrete behaviour in compression differs from that in tension. There are a few different failure modes of concrete material: tension cracking, compression crushing, spalling of concrete, etc.

Excess commuting and frictions in the labor market

ABSTRACT We propose a model of excess commuting based on search costs in the labor market and show how the equilibrium rate of excess commuting is determined by the degree of geographical job concentration – without neglecting the importance of the size of the labor market and commuting costs. We test – and largely confirm – the main predictions of our model using Belgian population data on commuting flows between all its 589 municipalities. Our approach is to aggregate the data into 640 sectors and skill-specific groups in order to generate heterogeneity in the excess commuting rate. We find that workers in sectors with a high degree of job concentration have lower rates of excess commuting and that workers that operate in larger labor markets, such as higher educated workers and men compared to women, have higher rates of excess commuting.

Monetary Policy and Bond Prices with Drifting Equilibrium Rates

We study drift and cyclical components in U.S. Treasury bonds. We find that bond yields are drifting because they reflect the drift in monetary policy rates. Empirically, modeling the monetary policy drift using demographics and productivity trends, plus long-term inflation expectations, leads to cyclical deviations of bond prices from their drift that predict bond returns in- and out-of-sample. These bond cycles can originate from term premia or temporary deviations from rational expectations in a behavioral framework. Through the lens of our model, we detect a significant role of the latter in determining the cyclical properties of yields with short maturities.

Trade Wars, Currency Wars

For most of the post WWII period, until recently, trade protectionism followed a downward trend, and was formulated in multilateral or bilateral agreements between countries. Recently however, there hasbeen a sharp shift towards unilateral, discretionary trade policy focused on short term macroeconomic objectives, and as a consequence, the use of trade policy has become entangled with that of monetary policy. This paper explores the consequences of this shift within a standard DSGE open economy macroeconomic model. We find that a discretionary non-cooperative approach to trade policy can significantly worsen macroeconomic conditions. Moreover, the stance of monetary policy has major implications for the degree of protection in a non-cooperative equilibrium. In particular, cooperative determination of monetary policy implies an increase in both equilibrium tariffs and inflation, and a significant fall in welfare. By contrast, when the exchange rate is pegged by one country, equilibrium rates of protection are generally lower, but in this case, there are multiple asymmetric equilibria in tariff rates which benefit one country relative to another. We also explore the determination of non-cooperative tariffs in a situation where monetary policy is constrained by the zero lower bound on nominal interest rates. (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This abstract was borrowed from another version of this item.) (This a (This abstract was borrowed from another version of this item.)

A study of degrowth paths based on the von Neumann equilibrium model

Abstract This paper revisits the von Neumann equilibrium model from a degrowth perspective. Degrowth can be either planned or autonomous based on voluntary simplicity (VS), characterized by voluntary constraints on the private consumptions. Any share of the working population is allowed to limit their private consumptions or ecological footprint. Degrowth means a lower economic growth rate as well as reductions in the usage of materials and fossil energy; however, when the economy cannot fit within the biophysical boundary despite such reductions, degrowth can also mean a deliberate transition towards lesser and cleaner production of a smaller number of goods. Taking ecological boundaries into consideration may thus switch the direction of an economy from growth to degrowth. Degrowth is consistent with economic equilibrium in the dynamic input-output model. Degrowth equilibrium results when a critical mass of the population prioritizes diminishing the ecological deficit over increasing the output levels. Green growth can take place during degrowth. While the economy gradually shrinks, the interest (profit) rate in macroeconomic equilibrium is negative due to the conservation target (excessive consumption has negative value to VS-type agents). Degrowing private consumptions implies less work, more leisure and better quality of the environment, improving social welfare. Degrowth can be advanced by adopting a more cooperative production system or by imposing high ecological taxes. The equilibrium model yields an argument for basic income as a means of supporting welfare during degrowth and of compensating for unpaid work. The open economy version of the model shows reduced scope for intra-industry trade between similar countries.

NmrLineGuru: Standalone and User-Friendly GUIs for Fast 1D NMR Lineshape Simulation and Analysis of Multi-State Equilibrium Binding Models

The ability of high-resolution NMR spectroscopy to readout the response of molecular interactions at multiple atomic sites presents a unique capability to define thermodynamic equilibrium constants and kinetic rate constants for complex, multiple-step biological interactions. Nonetheless, the extraction of the relevant equilibrium binding and rate constants requires the appropriate analysis of not only a readout that follows the equilibrium concentrations of typical binding titration curves, but also the lineshapes of NMR spectra. To best take advantage of NMR data for characterizing molecular interactions, we developed NmrLineGuru, a software tool with a user-friendly graphical user interface (GUI) to model two-state, three-state, and four-state binding processes. Application of NmrLineGuru is through stand-alone GUIs, with no dependency on other software and no scripted input. NMR spectra can be fitted or simulated starting with user-specified input parameters and a chosen kinetic model. The ability to both simulate and fit NMR spectra provides the user the opportunity to not only determine the binding parameters that best reproduce the measured NMR spectra for the selected kinetic model, but to also query the possibility that alternative models agree with the data. NmrLineGuru is shown to provide an accurate, quantitative analysis of complex molecular interactions.

The Global Equilibrium Real Interest Rate: Concepts, Estimates, and Challenges

Real interest rates have been persistently below historical norms over the past decade, leading economists and policymakers to view the equilibrium real interest rate as likely to be low for some time. Various definitions and approaches to estimating the equilibrium real interest rate are examined, including approaches based on the term-structure of interest rates and small macroeconomic models. The individual-country approaches common in the literature are extended to allow for global trend and cyclical factors. The analysis finds that global factors dominate the downward trend in the equilibrium interest rate across 13 advanced economies. A corollary of this finding is that the U.S. equilibrium rate may be substantially lower than estimated in U.S.-only studies. The analysis also highlights how the common global trend confounds empirical assessments of the determinants of movements in the equilibrium rate and the need to better integrate term-structure and macroeconomic approaches.

Labour market fluidity and employment outcomes in Colombia: Evidence from employer-employee linked data

Labour market flexibility has been a traditional subject of study in labour economics; recent literature has focused on the related concept of fluidity, broadly understood as the mobility of workers and jobs in the labour market. Here, we compute standard measures of fluidity for the Colombian urban labour market, finding evidence of increased fluidity, especially after 2010. Recent developments in equilibrium unemployment models predict, in general settings, a negative relationship between some fluidity measures and the equilibrium rate of unemployment. Recent literature on worker and job flows has identified benign aspects of fluidity, in that fluid labour markets are expected to have shorter average unemployment duration. We find evidence for a positive effect of fluidity on different employment and occupation indices using instrumental variable regression models that exploit variations in labour market outcomes and fluidity measures over time.

Synthesis and Kinetics of the N-(2-Methyl-6-ethyl phenyl)-1-methoxypropyl-2-imine Schiff Base Catalyzed by NKC-9 Cation Exchange Resin.

The kinetics of condensation reaction of methoxyacetone with 2-methyl-6-ethyl aniline catalyzed by NKC-9 cation exchange resin was studied for the first time. The reaction temperature of Schiff base synthesis was determined in the range of 367.15 to 401.15 K by the batch experiments, and influences of reactant molar ratio, temperature, catalyst dosage, and particle size on the ultimate conversion were also studied. The dynamic data were used to be relevant with PH, ER(1), ER(2), and Langmuir Hinshelwood Hougen Watson homogeneity models. Model parameters, including reaction equilibrium constants, activation energy, enthalpy change, entropy change, and rate constants, were solved. The accuracy of the model was validated by means of both experimental proofs and standard deviation between the predicted and experimental data. Finally, a series of characterization tests such as Fourier transform infrared spectroscopy, X-ray diffraction, and polarizing microscopy were performed to investigate the structure and properties of NKC-9.

Adsorption and dyeing properties of acid dyes on fine denier silk fibers

In this work, the surface morphology and diameter distribution of fine denier silk fiber were observed and measured. The adsorption property of acid orange 7 on the fine denier silk fiber was studied. The pseudo-first-order model and pseudo-second-order model adsorption kinetic models were employed to evaluate the experimental data. The effects of pH values and reaction temperature on the dyeing property were investigated. The results indicated that the fine denier silk fiber exhibited a uniform fiber diameter (9 µm), which is smaller than that of conventional silk fiber (16 µm). The adsorption process of the dye could be described using pseudo-second-order kinetic equations. A higher the amount of dye adsorption at equilibrium and faster adsorption rate was obtained for the fine denier silk fiber. The color strength of fine denier silk fibers was improved for the decreased pH values and increased temperature, which exhibited an excellent dyeing property.

Fabrication and evaluation of aminoethyl benzo-12-crown-4 functionalized polymer brushes adsorbents formed by surface-initiated ATRP based on macroporous polyHIPEs and postsynthetic modification

For the efficient extraction of lithium ions (Li+) from salt-lake brines, adsorbents with high adsorption capacity, fast equilibrium rate, and excellent selectivity are urgently needed. Herein, aminoethyl benzo-12-crown-4 (2AB12C4) functionalized polymer brushes (PVBC-g-PGMA-CE) from macroporous and polymeric high internal-phase emulsion (polyHIPEs) using surface-initiated ATRP and postsynthetic modification was constructed for selective recovery of Li+. Owing to the macroporous structure and high density of binding sites of PVBC-g-PGMA-CE, the equilibrium time was 50 min, and the maximum adsorption capacity was 4.76 mg g−1 at 25 °C. The equilibrium and kinetic studies indicated a monolayer and chemisorption process via homogeneous sites and host-guest interaction. Attributed to the size sieving effect and affinity difference, PVBC-g-PGMA-CE possessed the highest the binding capacities towards Li+ in the competitive adsorption, and the relative selective separation factors (αr) for coexisting ions (i.e. Ca2+, Mg2+, Na+ and K+) were all higher than 4.67. The adsorption amount of PVBC-g-PGMA-CE towards Li+ after five regeneration cycles was 97.30% of the first cycle. The results demonstrated that the developed PVBC-g-PGMA-CE was the promising adsorbent for the efficient and selective recovery of Li+.

Ultrafast and Highly Selective Uranium Extraction from Seawater by Hydrogel‐like Spidroin‐based Protein Fiber

AbstractFor the practical extraction of uranium from seawater, adsorbents with high adsorption capacity, fast equilibrium rate, high selectivity, and long service life are needed. Herein, a chimeric spidroin‐based super uranyl‐binding protein (SSUP) fiber was designed by fusing the gene of super uranyl‐binding protein (SUP) with the gene of spidroin. SUP endowed the SSUP fiber with high affinity and selectivity to uranium, and spidroin gave the SSUP fiber with high mechanical strength and high reusability. The wet SSUP fiber is a water‐rich hydrogel‐like structure, which provided abundant hydrophilic intermolecular space for the entrance of uranyl ions, and could accelerate the rate for uranium adsorption. In seawater, the SSUP fiber achieved a breakthrough uranium extraction capacity of 12.33 mg g−1 with an ultrashort equilibration time of 3.5 days, suggesting that SSUP fiber might be a promising adsorbent for uranium extraction from the natural seawater.

Ultrafast and Highly Selective Uranium Extraction from Seawater by Hydrogel-like Spidroin-based Protein Fiber.

For the practical extraction of uranium from seawater, adsorbents with high adsorption capacity, fast equilibrium rate, high selectivity, and long service life are needed. Herein, a chimeric spidroin-based super uranyl-binding protein (SSUP) fiber was designed by fusing the gene of super uranyl-binding protein (SUP) with the gene of spidroin. SUP endowed the SSUP fiber with high affinity and selectivity to uranium, and spidroin gave the SSUP fiber with high mechanical strength and high reusability. The wet SSUP fiber is a water-rich hydrogel-like structure, which provided abundant hydrophilic intermolecular space for the entrance of uranyl ions, and could accelerate the rate for uranium adsorption. In seawater, the SSUP fiber achieved a breakthrough uranium extraction capacity of 12.33 mg g-1 with an ultrashort equilibration time of 3.5 days, suggesting that SSUP fiber might be a promising adsorbent for uranium extraction from the natural seawater.

Element balance formulation in reactive compositional flow and transport with parameterization technique

We present a novel nonlinear formulation for modeling reactive-compositional flow and transport in the presence of complex phase behavior due to a combination of thermodynamic and chemical equilibria in multi-phase systems. We apply this formulation to model precipitation/dissolution of minerals in reactive multiphase flow in subsurface reservoirs. The proposed formulation is based on the consistent element balance reduction of the molar (overall composition) formulation. To predict the complex phase behavior in such systems, we include the chemical equilibrium constraints to the multiphase multicomponent negative flash calculations and solve the thermodynamic phase and chemical phase equilibria simultaneously. In this solution, the phase equilibrium is represented by the partition coefficients, whereas the chemical equilibrium reaction is represented by the activity coefficients model. This provides a generic treatment of chemical and thermodynamic equilibrium within the successive substitution loop of mulmultiphase flash to accommodate chemical equilibrium reactions (precipitation and dissolution reactions). Equilibrium Rate Annihilation matrix allows us to reduce the governing component conservation equations to element conservation equations, while the coupling between chemical and thermodynamic equilibrium is captured by a simultaneous solution of modified multiphase flash equations. The element balance equation written in terms of overall component mole fractions is modified and defined in terms of element mole fractions. Therefore, the primary set of governing equations are the element balance equations and the kinetic equations. This element composition of the mixture serves as an input to the modified multiphase flash computations, whereas the output is fractions of components in each phase, including solids. The nonlinear element–based governing equations are solved with the modified version of the operator-based linearization (OBL) approach where the governing equations are formulated in terms of space- and state-dependent parameters constrained by the solution of the extended multiphase flash. The element balance molar formulation along with the modified multiphase flash has been tested in a simple transport model with dissolution and precipitation reactions. The simulation of multidimensional problems of practical interest has been performed using the adaptive OBL technique. This is the first time when a robust multiphase multicomponent flash based on element fractions is coupled with an element balance–based compositional formulation and tested for multidimensional problems of practical interest. The proposed technique improves both robustness and performance of complex chemical models.

Temperature Evaluation of Curcumin Keto-Enolic Kinetics and Its Interaction with Two Pluronic Copolymers.

Curcumin (CUR), a natural hydrophobic polyphenol isolated from Curcuma longa, has been reported to possess two main equilibria in aqueous solutions, diketo/keto-enolic tautomerism and self-aggregation. The thermodynamics of tautomeric equilibrium is well established; however, its kinetic parameters have been sparsely studied. Various efforts have been made to improve CUR solubility in aqueous media. We evaluated how the kinetics of tautomerism and the interaction of CUR with pluronic P123 and F127 copolymers in solution were affected by temperature, using UV-vis and fluorescence spectroscopies. Pluronic particle sizes with and without CUR were acquired by dynamic light scattering. The interaction in the solid state was verified by differential scanning calorimetry (DSC). The equilibrium rate that displaces to the diketo form increased fivefold when the temperature rose from 294 to 314 K with an activation energy of 61.2 kJ mol-1. The CUR solubility increased from 2.58 to 6.77 mg g-1 when incorporated in P123 and from 0.05 to 3.54 mg g-1 when incorporated in F127 with a change in the temperature from 298 to 314 K. This process had a Gibbs free energy of around -1 and -13 kJ mol-1 because of CUR solubilization into the inner core of pluronic micelles. Particle sizes of about 11 nm were obtained for both copolymers containing CUR in an aqueous solution above the critical micelle temperature. DSC measurements showed melting point depression of both CUR and F127. P123 presented no significant variation in the melting point because of its low melting enthalpy. The results indicate that temperature significantly influences CUR kinetic tautomerism and its interaction with both P123 and F127 copolymers. P123 presents a higher interaction in aqueous solution with CUR than F127. Both pluronics could contribute to a safer and more efficient CUR administration in the bloodstream.

Learning in Contests with Payoff Risk and Foregone Payoff Information

We test whether deviations from Nash equilibrium in rent-seeking contests can be explained by the slow convergence of payoff-based learning. We identify and eliminate two sources of noise that slow down learning. The first source of noise is present because each action is evaluated against a different sample of actions of other players. We eliminate it by providing foregone payoff information, which allows all actions to be evaluated against the same sequence of opponent's actions. The second source of noise is present because of payoff risk, which reduces the correlation between expected and realized payoffs. We manipulate payoff risk using a 2x2 design: payoffs from contest investments are either risky (as in standard contests) or safe (as in proportional contests), and payoffs from the part of endowment not invested in the contest are also either safe (as in standard contests) or risky. We find that Nash equilibrium rates go up to 100% when payoff risk is not present and foregone payoff information is available, but are at most 20% in all other cases. This result can be explained by payoff-based learning but not by other theories that might interact with payoff risk (non-monetary utility of winning, risk-seeking preferences, spitefulness, probability weighting, QRE). We propose a hybrid learning model that combines reinforcement and belief learning with preferences, and show that it fits data well, mostly because of reinforcement learning. Additional support for learning comes from the persistence of the Nash equilibrium following the removal of foregone payoff information.

Determination of the Equilibrium Constant and Rate Constant of Protein-Oligonucleotide Complex Dissociation under the Conditions of Ideal-Filter Capillary Electrophoresis.

Ideal-filter capillary electrophoresis (IFCE) allows selection of protein binders from oligonucleotide libraries in a single step of partitioning in which protein-bound and unbound oligonucleotides move in the opposite directions. In IFCE, the unbound oligonucleotide does not reach the detector, imposing a problem for finding the equilibrium constant ( Kd) and rate constant ( koff) of protein-oligonucleotide complex dissociation. We report a double-passage approach that allows finding Kd and koff under the IFCE conditions, i.e. near-physiological pH and ionic strength. First, a plug of the protein-oligonucleotide equilibrium mixture passes to the detector in a pressure-driven flow, allowing for both the complex and free oligonucleotide to be detected as a single first peak. Second, the pressure is turned off and the voltage is applied to reverse the migration of only the complex which is detected as the second peak. The experiment is repeated with a lower voltage consequently resulting in longer travel time of the complex to the detector, greater extent of complex dissociation, and the decreased area of the second peak. Finally, the peak areas are used to calculate the values of Kd and koff. Here we explain theoretical and practical aspects of the double-passage approach, prove its validity quantitatively, and, demonstrate its application to determine Kd and koff for an affinity complex between a protein and its DNA aptamer. The double-passage approach for finding Kd and koff of protein-oligonucleotide complexes under the IFCE conditions is a perfect complement for IFCE-based selection of protein binders from oligonucleotide libraries.

Fe-based ceramic nanocomposite membranes fabricated via e-spinning and vacuum filtration for Cd2+ ions removal

In this work, vacuum filtered and polymer mixed e-spinning membranes (ESPMs) made from or doped with Fe-based nanomaterials were successfully fabricated to remove Cd2+ ions from a neutral aqueous solution. The used Fe-based nanomaterials including FeOOH precursor Nanowires (NWs), α-Fe2O3 NWs and Fe3O4 nanoparticles (NPs) were synthesized by elevating the hydrothermal reaction temperature from 250 °C to 500 °C or doing post-heating treatment. The adsorption results showed that vacuum filtered membranes (VFMs) overall performed a better Cd2+ ions removal behavior than e-spinning ones. Among them, VFM made from Fe3O4 NPs has the highest adsorption capacity (qt) with the adsorption amount of Cd2+ ions reaching about 29.3 mg/g within only 2 min due to the high specific surface area of NPs. Models of pseudo-first-order, pseudo-second-order and intraparticle diffusion were used to study the kinetics of Cd2+ ions removal process, and a high correlation coefficient (R2) of 0.99 was obtained when pseudo-second-order model was used. It was calculated that the equilibrium rate constant of VFM made from Fe3O4 NPs has reached about 0.28 g mg−1 min−1, much smaller than those of other membranes, which indicated a high Cd2+ ions removal efficiency.

THE DIFFERENCE IN THE LEVEL OF THE BODY BALANCE BETWEEN THE ELDERLY WHO DO GYMNASTICS WITH THOSE WHO DO NOT IN DAWAN DISTRICT

As getting older, a person will experience musculoskeletal weakness that will increase the risk of falling. Balance exercises to reduce the risk of falling is elderly gymnastics. The purpose of this study was to determine the difference in the level of body balance between elderly who did elderly gymnastics and those who did not in Dawan District. This research used observational analytic comparative research design with cross sectional approach method. The sample consisted of 44 people divided into two groups, the group of elderly who did gymnastics, and the group of elderly who did not do gymnastics at all. In the calculation of Mann Whitney-U showed that there was a difference in the body equilibrium rate between the elderly who didelderly gymnastics and those who did not with the value of p = 0,000 (p<0,05) in Dawan District.The conclusion of the study that there is a difference in the level of body balance between the elderly who did elderly gymnastics and those who did not in Dawan District.
 Keywords : Body Balance, Elderly, Elderly Gymnastics.

How process parameters and packing materials tune chemical equilibrium and kinetics in plasma-based CO2 conversion

Plasma (catalysis) reactors are increasingly being used for gas-based chemical conversions, providing an alternative method of energy delivery to the molecules. In this work we explore whether classical concepts such as equilibrium constants, (overall) rate coefficients, and catalysis exist under plasma conditions. We specifically investigate the existence of a so-called partial chemical equilibrium (PCE), and how process parameters and packing properties influence this equilibrium, as well as the overall apparent rate coefficient, for CO2 splitting in a DBD plasma reactor. The results show that a PCE can be reached, and that the position of the equilibrium, in combination with the rate coefficient, greatly depends on the reactor parameters and operating conditions (i.e., power, pressure, and gap size). A higher power, higher pressure, or smaller gap size enhance both the equilibrium constant and the rate coefficient, although they cannot be independently tuned. Inserting a packing material (non-porous SiO2 and ZrO2 spheres) in the reactor reveals interesting gap/material effects, where the type of material dictates the position of the equilibrium and the rate (inhibition) independently. As a result, no apparent synergistic effect or plasma-catalytic behaviour was observed for the non-porous packing materials studied in this reaction. Within the investigated parameters, equilibrium conversions were obtained between 23 and 71%, while the rate coefficient varied between 0.027 s−1 and 0.17 s−1. This method of analysis can provide a more fundamental insight in the overall reaction kinetics of (catalytic) plasma-based gas conversion, in order to be able to distinguish plasma effects from true catalytic enhancement.