Equilibrium Theory Research Articles

Policy implementation and policy instruments: The underdeveloped dimensions of the four “political” American policy process theories. A Western European perspective

AbstractThe fifth edition of “Theories of the Policy Process” represents a further step in consolidating these theories. However, four of them—Advocacy Coalition Framework, Multiple Streams Framework, Narrative Policy Framework, and Punctuated Equilibrium Theory—exhibit a few limitations in light of the characteristics of implementation and policy instruments due to their founding principles, the central role of pluralism and the will to abandon the original normativism of the policy sciences. Thus, these four theories seem to be framed to capture the politics of policy‐making in a dynamic way rather than to understand how policies are able to deliver results to society. This affects the relevance and applicability of these theories from a Western European perspective but probably also from other cultural and geopolitical perspectives. After a discussion of these limitations, the paper outlines a number of suggestions for overcoming them.

Fractionation of pequi pulp oil and modeling by thermodynamic phase equilibrium theory.

This study focused on evaluating the fractionation of pequi oil and modeling the process using solid-liquid equilibrium (SLE) theory. The pequi oil was comprehensively characterized, including its fatty acid (FA) and acylglycerol (AG) profiles, moisture content, acidity, carotenoid levels, and thermal behavior. Low acidity and partial acylglycerols content, along with its TAG profile (mainly OOP, POP, OOO and PPP) and melting behavior proved that, in fact, this oil is quite suitable for fractionation. Thermal fractionation was performed by centrifugation at 20°C (defined according to melting profile). The effect of agitation rate and static time were evaluated. At high rotation speeds (10,000 RPM) and with minimal influence from static time, two well-defined fractions were obtained: olein (liquid phase) at 64.3% and stearin (solid phase) at 30.48% by mass. These fractions were characterized based on their fatty acid (FA), acylglycerol (AG), and carotenoid content. SLE modeling of the fractionation process provided satisfactory results, especially for prediction of the global yield, and liquid fraction composition, being an interesting tool for presenting general information before experiments. Thermal fractionation proved to be an accessible and low-cost alternative for obtaining different feedstocks from pequi oil with technological applications in food industry.

The formation, maintenance, and loss of island biodiversity.

Due to the unique geographical features of large numbers, isolated by water and diverse formation histories, islands have become natural laboratories for ecological and evolutionary research. Islands have a high proportion of endemic species and disharmony in representing the species compared with that in the continent, which provides a good opportunity to explore the formation of island biodiversity. In this review, we focuse on island ecosystems and describes the progress of research in island biogeography in recent years from three aspects: formation, maintenance, and loss of island biodiversity. First, we take several representative island systems in the world as examples to introduce the formation mechanism of island biodiversity from species dispersal and immigration, population establishment and selection, species evolution and adaptive radiation. Based on the Equilibrium Theory of Island Biogeography, we then review the species-area relationship and species-isolation relationship and focus on the research progress in community assembly, including Diamond's rule, nestedness pattern, the framework of community structure of island biota, and species interactions on islands. We also discuss the high extinction risks of island species threatened from natural and human disturbances, especially from the impact of habitat loss and change, climate change, alien species invasion and the synergistic effect of these factors on the loss of island biodiversity. Finally, based on the status of island biodiversity, we summarized the current conservation practices for island biodiversity and possible research frontiers in island biogeographic studies.

A Study of the Quantitative Impact of Different Credit Policies on Real Estate Price Volatility in the Housing Finance Market

Real estate industry is an important industry of national economy in any country, which constitutes an important element of the wealth of the whole society and has a stable and long-term impact on national economy and social development. Based on the price theory of supply-demand equilibrium and the theory of real estate cycle fluctuation, the article combines the stock-flow model and vector autoregression model of real estate price to establish a quantitative analysis PVAR model of credit policy on real estate price fluctuation. Data from 31 provincial regions in China from 1998 to 2023 are selected as the research samples, and the specific effects of different credit policies on real estate price volatility in the housing finance market are verified through empirical analysis. When the scale of credit policy expands by 1 percentage point, real estate prices will increase by 0.00611 percentage points, while credit interest rates have a positive impact on real estate price volatility for 6 to 7 periods, and then change to a negative impact. Different regions under the credit policy on real estate price volatility there are differences, and the faster the growth rate of real estate prices in the region credit policy on real estate prices to promote the role of the more obvious. Real estate price regulation needs to accurately combine regional and economic development, so as to optimize the credit policy of the housing finance market, and then ensure the stability of real estate prices.

Spin fluctuations in the dissipative phase transitions of the quantum Rabi model

We investigate the dissipative phase transitions of the anisotropic quantum Rabi model with cavity decay and demonstrate that large spin fluctuations persist in the stationary state, having important consequences on the phase diagram and the critical properties. In the second-order phase transition to the superradiant phase, there is a significant suppression of the order parameter and the appearance of nonuniversal factors, which directly reflect the spin populations. Furthermore, upon entering a parameter regime where mean-field theory predicts a tricritical phase, we find a first-order phase transition due to the unexpected collapse of superradiance. An accurate and physically transparent description going beyond mean-field theory is established by combining exact numerical simulations, the cumulant expansion, and analytical approximations based on reduced master equations and an effective equilibrium theory. Our findings, compared to the conventional thermodynamic limit of the Dicke model, indicate a general tendency of forming extreme nonequilibrium states in the single-spin system, thus have broad implications for dissipative phase transitions of few-body systems. Published by the American Physical Society 2024

소방공무원 국가직 전환 정책변동에 관한 연구: 단절균형이론을 중심으로

This study explored the policy shift of converting firefighters to national positions through the lens of the Punctuated Equilibrium Theory. The initiative aimed to standardize fire administration services across local positions by transitioning firefighters to national roles. This study applies the theory of disconnection balance to analyze this policy transition, which took effect on April 1, 2020. Through major theoretical concepts, the study explores whether changes in policy (as the leading variable) trigger corresponding changes in budget allocation (as the lagging variable), thereby assessing the relationship between these factors.

Upper bound solution of the vertical bearing capacity of the pile-bucket composite foundation of offshore wind turbines

Pile-bucket composite foundations are regarded as a promising solution for offshore wind power infrastructure. However, accurately assessing their vertical ultimate bearing capacity remains a technical challenge. Therefore, establishing an upper bound solution of the ultimate bearing capacity of the composite foundations is of significant importance for their promotion and application. This study begins with small-scale model tests, using Abaqus for modeling based on the relevant test conditions. Next, following model validation, the vertical bearing capacity of the composite foundations under different H/D ratios and the corresponding soil failure modes are investigated. According to the upper limit method and the ultimate equilibrium theory, the kinematic velocity field is subsequently constructed to derive the upper bound solution of the vertical bearing capacity. Finally, the effectiveness and accuracy of the proposed theoretical upper bound solution are verified against the results of model tests, and this study hopes to provide a reference for the future design of vertical bearing capacity of pile-bucket composite foundations.

China and G7 in the Current Context of the World Trading

The paper analyses trade between the most developed economies of the world. The analysis is based on the previously proposed model of international trade. This model of international trade is based on the theory of general economic equilibrium. The demand for goods in this model is built on the import of goods by each of the countries participating in the trade. The structure of supply of goods in this model is determined by the structure of exports of each country. It is proved that in such a model, given a certain structure of supply and demand, there exists a so-called ideal equilibrium state in which the trade balance of each country is zero. Under certain conditions on the structure of supply and demand, there is an equilibrium state in which each country have a strictly positive trade balance. Among the equilibrium states under a certain structure of supply and demand, there are some that differ from the ones described above. Such states are characterized by the fact that there is an inequitable distribution of income between the participants in the trade. Such states are called degenerate. In this paper, based on the previously proposed model of international trade, an analysis of the dynamics of international trade of 8 of the world's most developed economies is made. It is shown that trade between these countries was not in a state of economic equilibrium. The found relative equilibrium price vector turned out to be very degenerate, which indicates the unequal exchange of goods on the market of the 8 studied countries. An analysis of the dynamics of supply to the market of the world's most developed economies showed an increase in China's share. The same applies to the share of demand.

The Equilibrium Theory of Biodiversity Dynamics: A General Framework for Scaling Species Richness and Community Abundance along Environmental Gradients

The Equilibrium Theory of Biodiversity Dynamics: A General Framework for Scaling Species Richness and Community Abundance along Environmental Gradients

Equilibrium loadings and adsorption isotherm model parameters estimated from multi-component breakthrough curves

Quantitative knowledge of competitive adsorption isotherms is essential for the design and optimization of adsorption based separation processes. Since the experimental determination of these thermodynamic functions is complicated and time consuming, there is a need for fast and easy to apply methods. In particular attractive are methods that evaluate measured breakthrough curves (BTC). Key features of these curves can be predicted with the equilibrium theory, which ignores kinetic effects that cause band broadening. If the adsorption equilibria can be described by the classical competitive Langmuir isotherm model, outlet concentration profiles can be calculated analytically. The paper summarizes and illustrates well-known classical results for N-component systems. The theory is applied to analyze experimentally determined BTC for a ternary mixture fed into an initially fully regenerated column under constant flowrate and under isothermal conditions. It is demonstrated that the retention times and intermediate plateau concentrations, which are observable for example in a single ternary BTC experiment, allow estimating a defined number of characteristic equilibrium loadings. These loadings can be directly used for easy estimation of the parameters of an assumed isotherm model. Various possibilities to use a reduced number of loadings and to include complementary results of standard pulse experiments are described. The isotherms generated from the ternary BTC are successfully validated by results of single component and ternary BTC experiments carried out subsequently. Options to generalize the method to determine isotherm model parameters from measured BTC to initially preloaded columns and to more complex mixtures are finally outlined.

Process swing adsorption with selective purge gas recirculation (PSA-SPUR): Adsorption process technology optimised for separation of heavy component from a gas mixture and its design for CO2 capture through Equilibrium Theory analysis

PSA-SPUR (Pressure Swing Adsorption with Selective Purge Gas Recirculation) has been developed aimed at separating the most strongly adsorbing component from a gas mixture at high product purity and recovery. The innovative strategy for designing a Pressure Swing Adsorption system features recycling its purge gas stream exiting the column and mixing it back into the feed. This operation enriches the mixed feed with an elevated fraction of the heavy component during the adsorption step, thus enhancing the PSA’s performance greatly. Reusing the purge gas helps significantly increase the product recovery compared to conventional methods where purge gas is simply discarded or taken as a low-quality product. For theoretical analysis of a PSA-SPUR system, a bespoke Equilibrium Theory model was developed and solved successfully, providing valuable insights into the performance of the PSA-SPUR system designed for capturing CO2 from a flue gas. The study revealed that there exists an optimum extent of purging that maximises the heavy component mole fraction in the mixed feed, leading to the best possible feed throughput of the adsorption system. Furthermore, the effects of the desorption pressure and feed composition on the PSA-SPUR system’s performance were investigated. The results indicate that the CO2 capture PSA-SPUR system using commercial zeolite 13X has excellent potential to achieve very high product purity and recovery, being allowed to operate at moderate vacuum pressures without having to compress the flue gas feed, even when the gas feed contains less than 10 mol% CO2.

Low-Carbon Oriented Collaborative Planning of Electricity-Hydrogen-Gas-Transportation Integrated System Considering Hydrogen Vehicles

Under the pressures of the energy crisis and climate change, hydrogen vehicles (HVs) have experienced significant growth in many countries recently. To promote the penetration of HVs, a low-carbon collaborative planning model based on carbon emission flow (CEF) and a modified user equilibrium theory is proposed for the electricity-hydrogen-gas-transportation integrated system. New carbon capture and storage equipment, steam methane reforming (SMR) equipment, and renewable energy equipment are planned in the model, which collaborates closely to provide green hydrogen. The proposed model considers the influence of different hydrogen production methods (electrolysis and SMR) on carbon emission reduction in the integrated energy network. Aiming to account for carbon emission from the consumption perspective, the emission caps are transferred from the energy supply side to the hydrogen production station side based on the CEF model. Additionally, the proposed modified user equilibrium model considering HV cruising range and hydrogen refueling station's location is innovatively utilized to solve the HV traffic flow assignment problem and evaluate the effectiveness of candidate roads in reducing congestion time. Overall, the total cost including equipment cost, energy consumption cost, and travel time cost is minimized to obtain the optimal integrated system planning results. Simulation results demonstrate that the proposed model is effective in reducing the carbon emissions and traffic time for the integrated network considering HV demands.

A model for predicting flexural capacity of PVC‐CFRP tube confined reinforced concrete beams

AbstractThis paper presents an experimental study on 18 specimens, including 15 polyvinyl chloride (PVC)‐carbon fiber‐reinforced polymer (CFRP) tube confined reinforced concrete beams with longitudinal CFRP sheets (PCT‐RCBs‐LCS) and 3 PVC‐CFRP tube confined reinforced concrete beams (PCT‐RCBs). The effects of five studied parameters, such as longitudinal reinforcement rate (), concrete strength grade (), width () and number () of longitudinal CFRP sheet, and specimen dimensions (), on the failure mode and flexural capacity are investigated. The PCT‐RCBs‐LCS with lower and fail by the breakage of the PVC tube and the fracture of longitudinal CFRP sheets. Conversely, the cracking of PVC tube dominates the damage of the PCT‐RCBs‐LCS with higher and , while the longitudinal CFRP sheets are not broken. The introduction of longitudinal CFRP sheets can significantly improve the flexural capacity. The ultimate flexural capacity of the PCT‐RCBs‐LCS increases as the , , , or increases. In addition. considering the influence of RC beam section shape, a model for predicting the ultimate flexural capacity of the PCT‐RCBs‐LCS is proposed based on the limit equilibrium theory and cross‐sectional strain relationship. The predicted results of the proposed model agree well with test data.

Effects of pH on Enzyme Activity in Pakistan

Purpose: The aim of the study was to assess the effects of pH on enzyme activity in Pakistan. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study indicated that effects of pH on enzyme activity are significant because enzymes are highly sensitive to the pH levels in their environment. Each enzyme has an optimal pH at which it functions most efficiently. Deviations from this optimal pH can lead to a decrease in enzyme activity. At extreme pH levels, enzymes may become denatured, altering their structure and impairing their ability to bind to substrates. This is because changes in pH can affect the ionic bonds and hydrogen bonds within the enzyme, altering its active site. As a result, enzyme activity typically increases as the pH approaches the optimal level, and decreases when the pH moves away from this point. Therefore, maintaining proper pH levels is crucial for the effective functioning of enzymes in biological systems. Implications to Theory, Practice and Policy: Lock and key model, induced fit theory and chemical equilibrium theory may be used to anchor future studies on the effects of pH on enzyme activity in Pakistan. In practical applications, industries utilizing enzymes should prioritize the implementation of rigorous pH monitoring and control systems to maintain optimal conditions for enzymatic activity. From a policy perspective, it is crucial for policymakers to establish clear guidelines governing the use of enzymes in industrial applications, with a particular emphasis on the importance of pH control in achieving optimal performance.

International experiences on active travel planning: Impact of the COVID-19 pandemic

The COVID-19 pandemic generated significant impacts on transport policy. Exploring barriers and enablers to active travel through the lens of the practitioners planning for and promoting its uptake can uncover underlying mechanisms that shape travel choices and encourage more effective interventions. This study uses online survey data from practitioners working in the planning and provision of active travel related initiatives (N = 40), to understand international experiences, as influenced by the surge of interest in active travel during the pandemic. We base our investigations and analysis on two policy process theories – the Multiple Streams Framework and Punctuated Equilibrium Theory. Drawing tools and concepts from both, we provide a synthesis of international experiences with planning for active travel, and analyse how professionals perceive existing obstacles and opportunities for active travel provision once the immediate impacts of the pandemic have waned. Our findings reveal a pervasive adherence to the status quo – while certain policies temporarily adapted to accommodate the pandemic’s disruptions, the pandemic failed to trigger substantial actions for our sample. The primary challenge lies in the enduring dominance of car-centric cultures and urban form, suggesting both a lack of community understanding about the issues associated with car usage, and ongoing structural barriers of cities planned around cars. Notwithstanding, the emergence of active travel projects and strategies since the onset of the pandemic, coupled with increasing public awareness of active travel, could be valuable in laying the groundwork for future long-term changes, even if their immediate impact is not yet evident.

Investigating the generation mechanism of nanobubbles and the ion-transport regulation on nanofiltration membranes for efficient salt-salt separation

Nanofoaming-assisted interfacial polymerization (IP) exhibits strong potential to regulate the structure and the separation performance of thin film composite (TFC) membranes. At present, it is recognized that when NaHCO3 is employed as an aqueous foaming agent, the generation of nanobubbles is ascribed to the NaHCO3 acidification and may be enhanced by increasing the NaHCO3 dosage. However, to more accurately measure the generation of nanobubbles, it is necessary to analyze the content and composition of carbonates in the aqueous solution at the initial and final states of interfacial polymerization, which is currently lacking in research. In this work, based on the chemical equilibrium theory, the aqueous carbonate chemistry and the quantity of CO2 released during IP was evaluated through monitoring the pH changes near the interface and calculating the carbonate distribution fraction. Results showed that the pH of the aqueous solution changed from 10.3 to 11.4 to 6.0–6.5 during interfacial polymerization when the NaHCO3 dosage was 0.00–0.10 wt%. However, this variation in pH was subtle (from ∼9.3 to ∼8.8) when 1.00 wt% NaHCO3 was added, leading to limited transformation of carbonate into H2CO3 and, consequently, less generation of CO2. In the whole dosage range of NaHCO3, 0.10 wt% NaHCO3 contributed to the maximum quantity of CO2 during IP, which was also confirmed by the vesicle-like membrane morphology. The resultant membrane achieved a superior salt-salt separation, with selectivity for Mg2+ and Li+/Na+/K+ enhancements of more than 2 times compared to the membrane without NaHCO3 dosage. This work proposed a new approach to evaluate the inner relationship between NaHCO3 dosage and nanobubble quantity during IP, which provides an ion-transport regulation mechanism of nanofiltration membranes for efficient salt-salt separation.

Using punctuated equilibrium theory to explain changes in policy outputs: The case of the United States Coast Guard

AbstractThis article explores the utility of punctuated equilibrium (PE) theory in explaining revolutionary organizational change in the public sector and its effects on policy implementation, with a focus on the United States Coast Guard. We illustrate our model using data from in‐depth interviews with current and former senior Coast Guard officers and enlisted personnel, as well as secondary sources such as historical accounts and budget data. Through content analysis, we argue that PE theory begins with a change in the public sector organization's external environment, which then affects organizational strategy, structure, power distribution, and outputs. Punctuated equilibrium theory proves to be a valuable lens for understanding policy outputs in relation to organizational change.Related ArticlesKwon, Sung‐Wook, and Sylvia Gonzalez‐Gorman. 2019. “Influence of Local Political Institutions on Policy Punctuation in Three Policy Areas.” Politics & Policy 47(2): 300–25. https://doi.org/10.1111/polp.12295.Neill, Katharine A., and John C. Morris. 2012. “A Tangled Web of Principals and Agents: Examining the Deepwater Horizon Oil Spill through a Principal–Agent Lens.”Politics & Policy 40(4): 629–56. https://doi.org/10.1111/j.1747‐1346.2012.00371.x.Peng, Peiwen, and Tangzhe Cao. 2023. “Attention, Institutional Friction, and Punctuated Equilibrium in China's Budget: Changes in Social Security and Employment Expenditure.” Politics & Policy 51(2): 256–82. https://doi.org/10.1111/polp.12523.

Deciphering transient carbon footprint for methane dry reforming over Ni@S-1 nanosheet zeolite catalyst

Carbon deposition, an inevitable product operated at high temperatures, is a headache-inducing obstacle to enhance catalyst stability for methane dry reforming (MDR). Herein, we have ingeniously designed sintering-resistant Ni@S-1 nanosheet zeolites to purposefully induce common linear and non-linear deactivation of catalysts during MDR reaction for deciphering carbon footprint. Multiple evidences unveiled that "transient carbon", composed of multi-phenyl-rings via rapidly rearrangement of CHx* fragments, was a crucial vane for catalyst deactivation. Accordingly, we proposed a dynamic equilibrium theory for the generation and elimination of "transient carbon". Achieving this balance was dependent of the matching degree between Ni0 nanoparticles and NiOx(OH)y, which both separately originated from the evolutions of 1:1 and 2:1 Ni phyllosilicates controlled by nanosheet thickness. Delightfully, synthetic Ni@S-1–60nm catalyst with an optimal ratio of Ni0/NiOx(OH)y contributed higher MDR activity and durability. These findings derived a new MDR reaction pathway and afforded value-filled information for developing high carbon-resistant MDR catalysts.

Dynamic spatial price equilibrium, dynamic user equilibrium, and freight transportation in continuous time: A differential variational inequality perspective

In this paper we provide a statement of dynamic spatial price equilibrium (DSPE) in continuous time as a basis for modeling freight flows in a network economy. The model presented describes a spatial price equilibrium due to its reliance on the notion that freight movements occur in response to differences between the local and distant prices of goods for which there is excess demand; moreover, local and distant delivered prices are equated at equilibrium. We propose and analyze a differential variational inequality (DVI) associated with dynamic spatial price equilibrium to study the Nash-like aggregate game at the heart of DSPE using the calculus of variations and optimal control theory. Our formulation explicitly considers inventory and the time lag between shipping and demand fulfillment. We stress that such a time lag cannot be readily accommodated in a discrete-time formulation. We provide an in-depth analysis of the DVI's necessary conditions that reveals the dynamic user equilibrium nature of freight flows obtained from the DVI, alongside the role played by freight transport in maintaining equilibrium commodity prices and the delivered-price-equals-local-price property of spatial price equilibrium. By intent, our contribution is wholly theoretical in nature, focusing on a mathematical statement of the defining equations and inequalities for dynamic spatial price equilibrium (DSPE), while also showing there is an associated differential variational inequality (DVI), any solution of which is a DSPE. The model of spatial price equilibrium we present integrates the theory of spatial price equilibrium in a dynamic setting with the path delay operator notion used in the theory of dynamic user equilibrium. It should be noted that the path delay operator used herein is based on LWR theory and fully vetted in the published dynamic user equilibrium literature. This integration is new and constitutes a significant addition to the spatial price equilibrium and freight network equilibrium modeling literatures. Among other things, it points the way for researchers interested in dynamic traffic assignment to become involved in dynamic freight modeling using the technical knowledge they already possess. In particular, it suggests that algorithms developed for dynamic user equilibrium may be adapted to the study of urban freight modelled as a dynamic spatial price equilibrium. As such, our work provides direction for future DSPE algorithmic research and application. However, no computational experiments are reported herein; instead, the computing of dynamic spatial price equilibria is the subject of a separate manuscript.

A framework for analyzing the most relevant indicators of ecohydrology in a changing environment

ABSTRACT Human activities and climatic changes have altered the hydrological ecosystem of the Min River Basin and affected in-river biodiversity. In this paper, the year of abrupt hydrological change was identified using multiple tests, and the drivers of ecohydrological change were quantified in conjunction with the Budyko coupled hydrothermal equilibrium theory. Combined with ecological flow indicators (ecological surplus (ES) and ecological deficit (ED)) calculated based on discharge hydrographs and multiple hydrological indicators (ES/ED), the degree of river hydrological alteration in the Min River Basin was comprehensively evaluated, and its impacts on in-river biodiversity analyzed. The results of the study showed that: (1) according to the Budyko theory, the influence of human activities on the runoff changes in the Min River Basin reached 56.80%, which was the main influence factor, followed by climatic factors (41.56% for precipitation and 1.64% for evapotranspiration); (2) dam construction has generally resulted in an increase in seasonal ES and a decrease in seasonal ED; (3) the combination of the ecological flow indexes with the ecologically relevant hydrological indicators not only reduces the redundancy between the parameters, but also reflects the essential hydrological information and ecological connotations, and it is an effective method for evaluating ecohydrological mechanisms.