Equilibrium Rate Research Articles

A post-pandemic new normal for interest rates in emerging bond markets? Evidence from Chile

Before the COVID-19 pandemic, researchers intensely debated the extent of the decline in the so-called equilibrium or natural rate of interest. Given the recent sharp increase in interest rates, we revisit this question in an emerging bond market context and offer a Chilean perspective using a dynamic term structure finance model estimated directly on the prices of individual Chilean inflation-indexed bonds with adjustments for bond-specific liquidity risk and real term premia. Beyond documenting the existence of large and time-varying liquidity risk premia in the bond prices, we estimate that the equilibrium real rate in Chile fell about 2 and a half percentage points in the 2003-2022 period and has remained low since then with model projections only suggesting a gradual reversal in coming years. Instead, recent increases in real interest rates in Chile are driven by spikes in the liquidity and term premia of inflation-indexed bond prices.

Accurately measuring slowly propagating flame speeds: Application to ammonia/air flames

Environmental concerns have driven the development of alternative fuels and refrigerant working fluids with low global warming potential. Ammonia (NH3) is a potential zero-carbon fuel, while hydrofluorocarbons (HFCs) like R-32 and R-1234yf are being adopted as refrigerants. When mixed with air, these compounds can sustain slowly propagating flames with laminar flame speeds less than 10 cm/s. Unlike typical hydrocarbon-fueled flames, these slow flames are influenced by buoyancy-induced flow and radiation heat loss. In this study, we experimentally investigate the flame speeds of NH3/air mixtures using the constant-pressure spherically expanding flame method, while circumventing gravity-induced natural convection, and account for radiation-induced inward flow. To mitigate buoyant convection, a low-cost drop tower was built and used to study slow spherically expanding flames in free fall. A computational model (SRADIF) is utilized that combines thermodynamic equilibrium and finite rate optically thin limit radiation heat loss calculations to estimate the inward flow. The developed methodology is utilized to investigate slowly propagating NH3/air flames over a range of equivalence ratios. A systematic approach was undertaken to understand and quantify the errors that could arise when deriving the laminar flame speed. It was found that attempting to study slowly propagating flames in a static configuration, as opposed to in free fall, results in large differences in flame dynamics and subsequently all derived quantities. It is necessary to study slowly propagating flames in free-fall. Additionally, using experimental data that has not been corrected for radiation-induced flow leads to large errors in all derived quantities. Furthermore, direct comparisons of experimental measurements and detailed flame simulations are found to be necessary to determine if existing extrapolation approaches are applicable to these slowly propagating flames, which are challenging to study.

Evaluation of transition rates from nonequilibrium instantons

Equilibrium rate theories play a crucial role in understanding rare, reactive events. However, they are inapplicable to a range of irreversible processes in systems driven far from thermodynamic equilibrium like active and biological matter. Here we develop an efficient numerical method to compute the rate constant of rare nonequilibrium events in the weak-noise limit based on an instanton approximation to the stochastic path integral and illustrate its wide range of application. We demonstrate excellent agreement of the instanton rates with numerically exact results for a particle under a nonconservative force. We also study phase transitions in an active field theory. We elucidate how activity alters the stability of the two phases and their rates of interconversion in a manner that can be well described by modifying classical nucleation theory. Published by the American Physical Society 2024

Thermal equilibrium as a predictor of growth efficiency in preterm infants.

Providing adequate nutrition to preterm infants to achieve postnatal growth similar to intrauterine growth remains challenging due to the unpredictability of individual determinants. We used a calculation program for infant incubators to compare the estimated heat balance with the caloric intake and growth rate in Very Low Birth Weight Infants (VLBWI). A group of 32 VLBWI was studied over a period of 14-28 days. An interrelationship between thermal equilibrium and growth rate was observed, with standardized incubator settings being unable to avoid periods of negative thermal balance and concomitantly poor growth rate. Determining personalized incubator settings by means of a calculation program could help improve nutrition and growth in preterm infants.

Promoting the adoption of digital technology: Strategic policy insights from a network effects model

This paper examines a dynamic model of digital adoption by firms, incorporating network effects and highlighting the crucial role of government intervention to avoid a low stable equilibrium. The paper presents a strategic policy framework for promoting digital adoption effectively, offering three key insights for policy efforts targeting SMEs.First, there is a risk of ending up at a stable low equilibrium rate of digital adoption despite an initial surge in interest. Sustaining momentum beyond initial promotion efforts is essential. Second, it is critical to make a significant push when the digital adoption rate is approaching critical mass. This tipping point enables continuous, self-sustaining expansion. Third, understanding technology adoption cycles and allocating resources effectively is crucial. Once the adoption rate passes the critical threshold, further adoption occurs without promotional interventions. Resources should then be reallocated to foster the adoption of new technologies or applications, ensuring optimal use of limited resources to drive ongoing innovation and progress.The study also reveals that countries with a larger population of SMEs, due to either a large population or strong entrepreneurial environment, may find it relatively easier to promote digital adoption in this sector.

Stability and qualitative dynamics of a class of three‐dimensional difference equation system of exponential type

In this paper, we study the boundedness, persistence, and global stability of the equilibrium point and rate of convergence of positive solutions of the exponential form of a system of difference equations where are constants and are initial values. Furthermore, some numerical examples are also given, which support our theoretical results.

A post-Kaleckian econometric analysis of interest rates, income distribution, capacity utilization, accumulation and profit rates: the case of Italy

The aim of this paper is to analyze the effects of interest rates on rates of capacity utilization, capital accumulation and profit in Italy within a post-Kaleckian theoretical framework. The model employed in the analysis, which was developed by Hein/Schoder (2011), is based on monetary- authority-controlled real long-term interest rates that affect the functional distribution of income. Interest rates directly and indirectly affect the equilibrium rates of capacity utilization, accumulation and profit at a given debt–capital ratio. Our findings based on two econometric methods revealed that a higher real long-term interest rate has an adverse effect on these three endogenous variables in the Italian economy.

Modeling the impact of pH and reservoir temperature on the dissolution of quartz mineral due to oilfield chemical treatment

The petroleum industry frequently uses oilfield chemicals, such as corrosion inhibitors, scavengers, drilling fluid, and chemical enhanced oil recovery methods, to improve oil recovery. However, these chemicals can negatively impact the geochemical characteristics of the formation, potentially leading to facility failure and reservoir formation damage. A study using PHREEQC was conducted to predict the impact of reservoir temperature and pH on quartz rock dissolution under different temperatures and pH levels. The results showed consistent dissolving rates for quartz at different pH levels. The solubility of quartz minerals was slightly affected by the solution pH, suggesting that the process variable pH has little effect on the equilibrium rate. However, precipitation caused quartz to dissolve at a rate of 0.04 mmol.L−1.s−1 at 45 °C but increased to 0.07 mmol.L−1.s−1 at 65 °C in 0.8 s. As temperature increased, quartz and NaNO3 solution interaction reached equilibrium concentrations in 0.8 and 2.7 s. The study concluded that temperature significantly impacts quartz dissolution during interaction with sodium nitrate oilfield chemicals compared to pH. The PHREEQ software is a useful research tool for simulating rock-fluid interactions resulting in reservoir formation dissolution and precipitation, which can cause formation damage and sand production.

The Role of Financial Innovations in the Relationship between Open Market Operations and Access to Credit by Small and Medium Enterprises in Kisumu County, Kenya

Purpose: This study investigated the role of financial innovations in the relationship between open market operations and access to credit by small and medium enterprises in Kisumu County. The specific objectives were to assess the effect of open market operations on access to credit by small and medium enterprises and to investigate the role of financial innovations in the relationship between open market operations and access to credit by small and medium enterprises in Kisumu County. The study was guided by Milton Friedman's Monetarism Theory. Methodology: The study adopted a descriptive research design with a target population of 1,472 SME owners/finance officers in Kisumu County. A sample of 420 was obtained, and a closed-ended questionnaire was used to collect primary data. Data was analyzed using descriptive, correlation and regression analyses. Results: Results showed that open market operations had a statistically significant effect on SMEs' access to credit in Kisumu County. Further, financial innovations statistically and significantly moderated the effect on the relationship between open market operations and access to credit by small and medium enterprises. The study concluded that SMEs' access to credit depended on the direct and indirect effects of open market operations and also that financial innovations moderated these effects. Contribution to theory, practice and policy: The implication is that open market operations should be used to gradually and in a predictive manner increase the quantity of money until an equilibrium rate of interest is attained. SMEs will also be able to access credit if the supply is adequate and the interest rate is at the desired level for the clients. The results of the independent variable of this study showed that even though OMO had a significant effect on access to credit, its contribution was minimal. This may imply that the instruments used in the open market operations may not be accessible by small traders due to the minimum amount required for investment. The players of the financial markets could, therefore, think of innovative ways to customize products for the small traders in the open market operations to ensure optimum access to credit by SMEs. This study found that financial innovations increased the effect of open market operations on SMEs' access to credit by increasing the variation of access to credit. The use of financial innovations should, therefore, be encouraged as a bridge that would enhance SMEs' access to credit. This is a major contribution to knowledge, as no study has established this fact. Policies that would ensure implementation and control of the open market operations should be formulated. Mechanisms for firm checks should be crafted to ensure efficient and effective implementation of the same. These policies should be reviewed regularly to ensure they are current and offer proper guidance. Their implementation could ensure optimum utilization of the investment channels, hence ensuring the growth and stability of the economy.

Potentiometry in determining the antioxidant capacity of compounds of different hydrophilicity in the joint presence using mixed solvents and surfactants.

In this work, for the first time, the potentiometric method was used to determine the antioxidant capacity (AOC) of compounds of different hydrophilicity in the joint presence using mixed solvents and surfactants. The AOC of model solutions of antioxidants of different hydrophilicity was determined separately and in the joint presence in the media of phosphate buffer-surfactant and mixed solvents-surfactant, using as an example the ascorbic acid and the α-tocopherol. It was shown that the surfactant Triton X-100 is able to solubilize α-tocopherol under the selected conditions, allows to obtain reproducible and accurate results, and has less effect on the equilibrium rate of the K3[Fe(CN)6]/K4[Fe(CN)6] system. Phosphate buffer-ethanol and phosphate buffer-acetonitrile media in the 3:2 ratio with Triton X-100 (5mmol/dm3) were chosen as the analysis conditions (RSD ≤ 6%). The range of determined concentrations was (0.006-0.5)m mmol/dm3 in phosphate buffer-ethanol and (0.006-0.3)m mmol/dm3 in phosphate buffer-acetonitrile. AOC of raw materials infusions was determined in selected media. The positive correlation with the well-known Folin-Ciocalteu assay was obtained.

Relativistic coupled-cluster simulation of the kinetics of the hydrolysis of uranium hexafluoride

Uranium hexafluoride ( UF 6 ) is used ubiquitously in the nuclear fuel cycle. Its spontaneous hydrolysis in the presence of atmospheric moisture is well known but the associated reaction mechanism is poorly understood. Here a computational study was undertaken with the aim of characterizing the rate-limiting step of the hydrolysis of UF 6 under dry conditions. Toward this end, we began by examining the convergence of various energy contributions to the atomization enthalpy ( Δ H at ) of UF 6 and its hydrolysis product, UO 2 F 2 . This enabled a refinement of our previous composite method, resulting in a composite method with improved accuracy that also scales well by leveraging existing massively-parallel codes. We find that extremely high levels of theory are required to obtain Δ H at within experimental error bars, in agreement with the literature. Having calibrated our composite scheme, we proceed to investigate approximations appropriate for computing accurate binding energies and barrier heights on the potential energy surface governing the hydrolysis of UF 6 . In combination with high-accuracy relative energies, a master equation approach is used to generate rate constants, and comparisons are made with recent measurements [Richards et al., RSC Adv., 2020, 10, 34729]. Based on kinetic and equilibrium arguments, we conclude that the hydrolysis of U F 6 , when proceeding under very dry conditions, is unlikely to be initiated via U F 6 + H 2 O → UF 5 OH + HF type reactions. Finally, computed equilibrium constants and rate coefficients are tabulated for the temperature range 300–1800 K.

Synthesis of HHTPB by partial hydrogenation of HTPB using copper chromite as a catalyst

AbstractHTPB (hydroxyl‐terminated polybutadiene) is a well‐established binder in the composite solid propellant owing to its excellent compatibility with ammonium perchlorate (AP) and aluminium (Al) particles in giving rise to optimal ballistic and mechanical properties. Efforts are being made to improve the ballistic properties further, such as specific impulse. One way of increasing the specific impulse is to hydrogenate HTPB, which decreases the molecular mass of the combustion product gases. This paper is a summary of efforts in synthesizing hydrogenated HTPB (HHTPB) using copper chromite (CC) as a catalyst. A novel synthesis methodology is developed for HHTPB using a temperature‐programmed batch reactor with a variable speed stirrer and an instrumentation system to maintain the desired liquid reactant temperature. A process cycle is developed that includes addition sequence and reaction time. The product is analyzed using 1H‐NMR and FTIR to estimate the degree of hydrogenation and the geometrical isomers respectively. The estimated apparent equilibrium rate constants from the degree of hydrogenation values are respectively 74 and 2034 L/(mol MPa) for non‐catalyzed and catalyzed systems, indicating the effectiveness of the catalyst. This is also substantiated by the reduction in Gibbs free energy (ΔG), to an extent of 4.48 kJ/mol. Thermogravimetry examination indicates that the decomposition temperature of HHTPB produced by the catalytic method is marginally higher compared to HTPB. DSC curves indicate that the decomposition enthalpy of HHTPB is higher than that of HTPB. In summary, this paper proposed and validated a novel method in the preparation of HHTPB using copper chromite.

Facile hydrothermal assembly of three-dimensional GO-MTZE composite and its adsorption properties toward Cu2.

Three-dimensional (3D) graphene oxide (GO)-based aerogels, GO and 4-methyl-5-thiazoleethanol (MTZE) composites, were prepared by a facile hydrothermal method. Due to the hydrogen bonding and π-π stacking interactions, the produced 3D GO-MTZE composites possessed large cylindrical structures. The morphologies, composition, and chemical states of 3D GO-MTZE3:1 composite were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and N2 adsorption-desorption isotherms based on the Brunauer-Emmett-Teller (BET) method. The existence of nitrogen (N)-containing heterocyclic system and oxygen (O)-containing branched chain of MTZE contributed to the formation of 3D structures, while the complexation effect of heterocyclic sulfur (S)- and N-containing functional groups of MTZE for metal cations dominated the adsorption performance of 3D GO-MTZE3:1 composite, which could selectively adsorb copper ions (Cu2+). In addition, the better hydrophobic property of 3D GO-MTZE3:1 composite facilitates its facile recycling from aqueous solution after adsorption. The adsorption data of 3D GO-MTZE3:1 composite toward Cu2+ fitted well (R2 = 0.9996) with the linear pseudo-second-order kinetic model, giving an equilibrium rate constant (k2) of 0.0187gmg-1min-1. The linear Langmuir isothermal model could more accurately describe the experimental data, indicating the adsorption process is mainly dominated by the complexation interactions between MTZE and Cu2+. The thermodynamic parameters of ΔG° (< 0), ΔH° (> 0), and ΔS° (> 0) further indicate that the adsorption is a spontaneous and endothermic, confirming that the complexation between Cu2+ and 3D GO-MTZE3:1 composite occurs. Due to its high selectivity for Cu2+, good hydrophobicity, and excellent stability, the developed 3D GO-MTZE3:1 composite possesses might be promisingly used in the aqueous selective enrichment/removal of Cu2+.

Adsorption isotherms and kinetic studies for the defluoridation from aqueous solution using eco-friendly natural adsorbent like Terminalia Chebula

A practical technique for removing fluoride from aqueous solutions by adsorption was created using the natural adsorbent known as Terminalia Chebula with a primary emphasis on adsorption isotherms and kinetic studies. The experimental results showed the best conditions for removing fluorine ions as follows: the dosage of the natural adsorbent: 50 mg/L, contact reaction time: 40 min, shaking speed = 120 rpm, temperature = 32 °C. The amount of removal of fluorine ions was found to be >98 % fluoride within a shorter time and reached adsorption equilibrium within 40 min with a maximum defluoridation capacity of 20.92 mg/g. At lower solution pH (3 to 5), there is higher fluoride adsorption on the adsorbent surface and as the pH becomes alkaline (pH > 7) the adsorption capacity decreased. The two co-ions namely NO3− and Cl− removed the fluoride 79 % whereas, the phosphate ions did not have any marked effect on the defluoridation. The pseudo-second-order kinetic order such Langmuir, Empirical Freundlich, Temkin and Dubinin–Radushkevich isotherms can well predict the adsorption equilibrium rate to be at 0.044 mg/L with contact time (t) of 30 min. In addition to that the adsorption is characterized by SEM, X-ray diffraction and FTIR techniques. This study has ultimately found that the Terminalia Chebula is a workable, natural material for fluoride elimination.

АНАЛІЗ РОЗВИТКУ РЕАКЦІЇ ОКИСЛЕННЯ ВУГЛЕЦЮ НИЗЬКОВУГЛЕЦЕВОЇ СТАЛІ В КОВШІ ПІД ВАКУУМОМ

The object of research is the process of vacuuming steel in a ladle. The purpose of the study is to determine the degree of approach of degassing reactions to equilibrium and removal rates by articles. Research methods - theoretical studies are based on the basic provisions of physical chemistry and the theory of metallurgical processes, thermodynamic calculations of the non-equilibrium reactions of degassing. Scientific novelty - in vacuum degassing processes, the approximation of the corresponding reactions to equilibrium plays a significant role, in industrial vacuum installations, the equilibrium between carbon and oxygen dissolved in steel is not achieved due to ex-tremely small concentrations of interacting substances, the speed of the chemical reaction decreases so much that it does not allow for processing time to even approach the state of thermodynamic equilibrium. Practical significance - to ensure a high degree of implementation of the deoxidizing ability of carbon in vacuum conditions, it is neces-sary to: apply the main lining of steel pouring ladles; maintain a high basicity of slag and a minimum content of iron oxides in it; mix the melt in the ladle with an inert gas to facilitate the conditions for the nucleation of carbon oxidation reaction products.

Biocompatible nanoparticles for metals removal from fresh water with potential for rare earth extraction applications

Freshwater contamination by metals can come from a variety of sources and be damaging to wildlife, alter landscapes, and impact human health. Metals removal is desirable not only for improving water quality and preventing adverse effects but also for metals collection and recycling. Nanoadsorption of metals is economically feasible and nanoscale materials exhibit a high surface-area-to-volume ratio that is promising for high adsorption and reactivity. However, the extraordinarily small dimensions of these materials allow them to maneuver biological systems, and combined with high reactivity, this translocation can result in toxicity. In this work, nanoparticles (NPs) composed of a magnetite core coated in hydroxyapatite (HA) and functionalized for adsorption with titanium dioxide (TiHAMNPs) were synthesized. The magnetic core enabled NP retrieval, while HA enhanced adsorption and minimized toxicity. Here, synthesis and characterization are presented, revealing a stable NP structure exhibiting a near neutral surface charge. Results of adsorption studies showed that as compared to silica-coated magnetite nanoparticles (SiMNPs), traditionally used for this application, TiHAMNPs exhibited significantly higher adsorption (43.28% more Cu removal) after 24 h. The equilibrium rate constant for the adsorption of Cu by TiHAMNPs was 0.0003 g/(min*mg) and TiHAMNP adsorption data indicated that TiHAMNPs adsorb metals in a monolayer at the particle surface with a maximum capacity of 2.8 mmol/g. Metabolic and toxicity assays showed TiHAMNPs were highly biocompatible as compared to SiMNPs. This work also explores rare earth element (REE) separation applications of TiHAMNPs, finding that TiHAMNPs may provide a promising alternative for REE retrieval and/or separation.

Modeling of vacuuming of low-carbon steel in a ladle taking into account the approach of degasation reactions to equilibrium

The object of research is the process of vacuuming steel in a ladle. The purpose of the study is to determine the degree of approach of degassing reactions to equilibrium and removal rates by articles. Research methods - theoretical studies are based on the basic provisions of physical chemistry and the theory of metallurgical processes, thermodynamic calculations of the non-equilibrium reactions of degassing. Scientific novelty - in vacuum degassing processes, the approximation of the corresponding reactions to equilibrium plays a significant role, in industrial vacuum installations, the equilibrium between carbon and oxygen dissolved in steel is not achieved due to extremely small concentrations of interacting substances, the speed of the chemical reaction decreases so much that it does not allow for processing time to even approach the state of thermodynamic equilibrium. Practical significance - to ensure a high degree of implementation of the deoxidizing ability of carbon in vacuum conditions, it is necessary to: apply the main lining of steel pouring ladles; maintain a high basicity of slag and a minimum content of iron oxides in it; mix the melt in the ladle with an inert gas to facilitate the conditions for the nucleation of carbon oxidation reaction products.

May Not Tell Us Everything: Transient Disease Dynamics of Some SIR Models Over Patchy Environments.

This paper examines the short-term or transient dynamics of SIR infectious disease models in patch environments. We employ reactivity of an equilibrium and amplification rates, concepts from ecology, to analyze how dispersals/travels between patches, spatial heterogeneity, and other disease-related parameters impact short-term dynamics. Our findings reveal that in certain scenarios, due to the impact of spatial heterogeneity and the dispersals, the short-term disease dynamics over a patch environment may disagree with the long-term disease dynamics that is typically reflected by the basic reproduction number. Such an inconsistence can mislead the public, public healthy agencies and governments when making public health policy and decisions, and hence, these findings are of practical importance.

The Natural Rate of Interest in the Euro Area: Evidence from Inflation-Indexed Bonds

The so-called equilibrium or natural rate of interest, widely known as r*t, is a key variable used to judge the stance of monetary policy. We offer a novel euro-area estimate based on a dynamic term structure model estimated directly on the prices of bonds with cash flows indexed to the euro-area harmonized index of consumer prices with adjustments for bond-specific risk and real term premia. Despite a recent increase, our estimate indicates that the natural rate in the euro area has fallen about 2 percentage points on net since 2002 and remains negative at the end of our sample. We also devise a related measure of the stance of monetary policy, which suggests that monetary policy in the euro area was not accommodative at the height of the COVID-19 pandemic.

A Post-Pandemic New Normal for Interest Rates in Emerging Bond Markets? Evidence from Chile

Before the COVID-19 pandemic, researchers intensely debated the extent of the decline in the steady-state short-term real interest rate—the so-called equilibrium or natural rate of interest. Given the recent sharp increase in interest rates, we revisit this question in an emerging bond market context and offer a Chilean perspective using a dynamic term structure finance model estimated directly on the prices of individual Chilean inflation indexed bonds with adjustments for bond-specific liquidity risk and real term premia. We estimate that the equilibrium real rate in Chile fell about 2 and a half percentage points in the 2003-2022 period and has remained low since then.