Degree Of Irreversibility Research Articles

Innovative biogas energy system: Enhancing efficiency and sustainability through multigeneration integration

This research suggests using landfill gas, derived from landfilling operations, as a feasible alternative to fossil fuels. This study introduces a novel and all-encompassing method for utilizing landfill biogas. The proposed system utilizes a supercritical Brayton cycle with carbon dioxide as the working fluid, a transcritical CO2 cycle, two ammonia Rankine cycles, a single-effect desalination cycle, a proton exchange membrane electrolyzer, and an improved Kalina cycle. The system underwent evaluation using Aspen HYSYS software, enabling assessments in terms of energy, exergy, thermo-economic, and environmental variables. The examination of the findings indicates that the suggested solution has much higher energy efficiency compared to similar studies. The assessments determined the energy efficiency of the process in power generation, combined heat and power, combined cooling, heat and power, and multigeneration modes to be 23.62 %, 80.89%, 81.19%, and 82.72%, respectively. Furthermore, environmental research has revealed that the new process emits a total of 1743 kg/h of carbon dioxide and has an emission rate of 0.23 kg/kWh. The exergy analysis indicated that the fuel burner exhibited the greatest degree of irreversibility, accounting for 40%. Furthermore, a sensitivity analysis was performed on crucial parameters, including the temperature of the heat source in the single-effect desalination section and the rate at which water flows into the electrolyzer. The objective was to evaluate the influence of changes in these parameters on energy efficiency, exergy efficiency, carbon dioxide emission intensity, product production rate, and levelized energy cost. The economic analysis determined that the proposed scheme would have a total annual cost of 8,667,124 $ with a levelized energy cost of 0.17 $/kWh.

Exact Time-Dependent Thermodynamic Relationships for a Brownian Particle Navigating Complex Networks

The thermodynamic characteristics of systems driven out of equilibrium are examined for M Brownian ratchets organized in a complex network. The precise time-dependent solution reveals that the entropy S, entropy production ep(t), and entropy extraction hd(t) of the system in complex networks increase with system size, which is plausible as these thermodynamic quantities display extensive properties. In other words, as the number of lattice sites increases, the entropy S, entropy production ep(t), and entropy extraction hd(t) increase, demonstrating that these complex networks cannot be reduced to the corresponding one-dimensional lattice. Conversely, the rates for thermodynamic quantities such as velocity V, entropy production rate e˙p(t), and entropy extraction rate h˙ d(t) become independent of the network size in the long-term limit. The exact analytic results also indicate that the free energy decreases with system size. The model system is further analyzed by incorporating heat transfer via kinetic energy. Since heat exchange via kinetic energy does affect the energy extraction rate, the heat dumped to the cold reservoirs also contributes to internal entropy production. Consequently, such systems exhibit a higher degree of irreversibility. The thermodynamic features of a system operating between hot and cold baths are also compared and contrasted with a system functioning in a heat bath where temperature varies linearly along the reaction coordinate. Regardless of the network arrangements, the entropy, entropy production, and extraction rates are significantly larger for the linearly varying temperature case than for a system operating between hot and cold baths.

Multiscale Irreversibility Analysis of Time Series Based on Permutation Jensen–Shannon Distance

In this study, we propose a multiscale permutation Jensen–Shannon distance (MPJSD) to measure irreversibility of complex time series. The new quantifier is based on symbolic permutation pattern and Jensen–Shannon distance. As an alternative, the new method offers the best characterization of the underlying irreversibility on different scales. The ARFIMA process and three dissipative chaotic systems are used to verify the effectiveness of the new method. The numerical results indicate that the MPJSD can unveil subtle and interesting findings on different scales and the permutation Jensen–Shannon distance (PJSD) is scale-dependent. Furthermore, we apply the approach to detect the multiscale irreversibility of ECG and financial data. The underlying irreversible nature of the investigated series is well discriminated. The method here introduced gives a new way to distinguish different degrees of irreversibility.

Multielectron Transfer in Halogen Batteries

AbstractMultielectron transfer in halogen batteries is a promising solution in pursuing high‐energy‐density and affordable energy storage systems. Interest in rich chemistries derived from unique valence electron structures of halogens is surging in electrode material design. However, deploying multielectron transfer chemistry comes with challenges, including limited redox reactivity and degrees of electrochemical irreversibility, which contribute to poor charging and cycling. To address these challenges, researchers explore physical/chemical strategies to activate high valence reactions and more electron transfer numbers and fix unstable valence state species through electrolyte and electrode regulation. This Concept presents the basic understanding of multielectron transfer electrochemistry concerning theoretical energy capabilities and electronic configuration evolutions. We divide multielectron transfer into two types: single and multi‐redox centers, providing an overview of the current development of multielectron transfer and hoping it will spur more intensive efforts towards a diverse energy future.

The temporal asymmetry of cortical dynamics as a signature of brain states

The brain is a complex non-equilibrium system capable of expressing many different dynamics as well as the transitions between them. We hypothesized that the level of non-equilibrium can serve as a signature of a given brain state, which was quantified using the arrow of time (the level of irreversibility). Using this thermodynamic framework, the irreversibility of emergent cortical activity was quantified from local field potential recordings in male Lister-hooded rats at different anesthesia levels and during the sleep-wake cycle. This measure was carried out on five distinct brain states: slow-wave sleep, awake, deep anesthesia–slow waves, light anesthesia–slow waves, and microarousals. Low levels of irreversibility were associated with synchronous activity found both in deep anesthesia and slow-wave sleep states, suggesting that slow waves were the state closest to the thermodynamic equilibrium (maximum symmetry), thus requiring minimum energy. Higher levels of irreversibility were found when brain dynamics became more asynchronous, for example, in wakefulness. These changes were also reflected in the hierarchy of cortical dynamics across different cortical areas. The neural dynamics associated with different brain states were characterized by different degrees of irreversibility and hierarchy, also acting as markers of brain state transitions. This could open new routes to monitoring, controlling, and even changing brain states in health and disease.

Irreversibility in belief dynamics: Unraveling the link to cognitive effort.

The relationship between time irreversibility in neuronal dynamics and cognitive effort is a subject of growing interest in the scientific literature. Although correlations between proxies of both concepts have been experimentally observed, the underlying precise linkage between them remains elusive. Here we investigate the case of learning in decision-making tasks; we do so by introducing a thermodynamically grounded metric-inspired by Landauer's principle-which connects time-irreversible information processing to energy consumption. Equipped with this metric, we investigate the role of macroscopic time-reversal symmetry breaking in belief dynamics for the case of an agent with finite sensitivity while performing a static two-armed bandit task-a standard setup in cognitive neuroscience. To gain insights into the belief dynamics, we analogize it to the dynamics of an active particle subject to state-dependent noise and living in a two-dimensional space. This mapping allows an analytical description of learning-induced biases. We deeply explore the case of Q-learning with forgetting the nonchosen option. In this case, learning-induced risk aversion is formally equivalent to standard thermophoresis, i.e., the net motion towards low-temperature regions. Finally, we quantify the irreversibility of belief dynamics in the steady state for different bandit configurations, sensitivity levels, and exploitative behavior. We found a strong correlation in high-sensitivity learning between heightened irreversibility in belief dynamics and improved decision-making outcomes. Notably, as the task's difficulty increases, a greater degree of irreversibility in belief dynamics becomes necessary for having superior performances; this explicitly unravels a plausible connection between time irreversibility and cognitive effort. In conclusion, our investigation reveals that irreversibility in belief dynamics bridges out-of-equilibrium statistical physics concepts and cognitive neuroscience. In decision-making contexts, this perspective offers insights into the notion of cognitive effort, suggesting a potential mechanism driving the evolution of living systems toward out-of-equilibrium structures.

Heterogeneity in the effects of uncertainty shocks on labor market dynamics and extensive vs. intensive margins of adjustment

The real option value theory posits that non-convex adjustment costs pertaining to a firm's input are central to comprehending the consequences of increased uncertainty. This paper leverages the diversity observed at both sectoral and country levels in the degree of irreversibility associated with hiring and firing, a critical factor generating what is commonly referred to as “wait-and-see” behavior in times of heightened uncertainty. Our empirical findings reveal two key insights. First, in alignment with the concept of second-moment shocks, uncertainty shocks predominantly influence the labor market through the extensive margin rather than the intensive margin. Second, the effects of uncertainty shocks exhibit pronounced heterogeneity across countries and industries, and the adverse employment effects (extensive margin) are amplified in a country with strict employment protection or in an industry characterized by a higher natural layoff rate, consistent with the real option theory.

Measuring irreversibility via trend pattern lengths

In this work, we present a method to assess irreversibility in real-valued time series. Our approach introduces a novel measure based on the statistics of what we term “trend patterns.” By dividing a real-valued time series into subsequences that exhibit either increasing or decreasing trends, we define distributions representing the duration of uptrend and downtrend subsequences. When the process is reversible, these distributions should coincide. Consequently, we quantify the degree of irreversibility by measuring the statistical deviations between them. Our findings demonstrate the efficacy of this approach in identifying reversible and irreversible time series, even when working with not-so-long sample sizes. We have successfully applied this irreversibility index to real-world time series, particularly financial data sourced from cryptocurrency markets and heartbeat time series. Our analysis proves that the introduced method is effective in evaluating the irreversibility of real-valued time series without implementing any codification process.

Application of Potentiometric and Electrophoretic Measurements to Evaluate the Reversibility of Adsorption of Divalent Ions from a Solution on Titanium Dioxide

The adsorption of divalent ions on metal oxides is controlled by the pH of a solution. It is commonly assumed that this is a reversible process for pH changes. However, there are reports that the sorption of ions on oxides may not be reversible. To verify this, we used potentiometric titration, ion-selective electrodes (ISEs), and electrokinetic measurements to examine the reversibility of the adsorption of hydrogen ions and three metal ions (Ca2+, Cu2+, and Fe2+) on TiO2. The ferrous ion was used as a reference because its adsorption is entirely irreversible. The surface charge determined by potentiometric titration and the adsorption edges measured using ISE indicate that the adsorption of copper ions is reversible with changes in pH. In the case of calcium ions, the results suggest a certain degree of irreversibility. There are apparent differences in the electrokinetic potential data obtained during titration with base and acid, which suggests that the adsorption is irreversible. We have explained this contradiction by considering the complex and dynamic nature of electrophoretic mobility. In our opinion, potentiometric titration may be the simplest and most reliable method for assessing the reversibility of multivalent ion adsorption.

Constitutive relationships for osteonal microcracking in human cortical bone using statistical mechanics

The post-elastic mechanical behavior of cortical bone, which is represented by extensive microcracking once the elastic regime is exceeded, has been characterized by a nonlinear constitutive relationship for osteonal microcracking. The relationship/model is based on the formalism of Statistical Mechanics, allowing the degree of irreversibility to be calculated using the increase in entropy associated with the progression of microcracking. Specific tensile and bending tests were conducted to compare theoretical predictions of constitutive relationships to empirical curves. In addition, the tests were utilized to determine the model’s parameters, whose values were used to explicitly calculate the entropy increase. A large sample was used: 51 cortical bone coupons (dog-bone-shaped specimens) were extracted from the 4th ribs of numerous individuals and subjected to uniaxial tensile testing. Additionally, fifteen complete 4th ribs were used for bending tests. Displacement and strain fields were measured for both types of tests using digital image correlation or video recordings of the tests. All experimental specimen data were successfully fitted to the model, and all constitutive parameter values were found to be correlated with anthropometric variables. Explicit entropy calculations indicate that microcracking is minimal for low strain and, initially, stress is nearly proportional to strain. After a certain point, significant microcracking occurs, and the relationship between stress and strain becomes invalid. Several significant associations between constitutive parameters and age have also been identified.

The Microbiomes of Various Types of Abandoned Fallow Soils of South Taiga (Novgorod Region, Russian North-West)

More than 30 years have passed after the collapse of the Soviet Union, and huge areas of soil were left in a fallow state. The study of the microbiological status of fallow soils is an extremely urgent task because fallow soils represent the “hidden” food basket of Eurasia. In this context, we studied the influence of land use type (pasture, vegetable garden, hayfield, or secondary afforestation) on key agrochemical parameters and parameters of soil microbial biodiversity. All anthropogenically transformed soils included in the analysis showed increased humus content and pH shift to a more neutral side compared to the mature soil; the same seemed to be the case for all nutrient elements. It was established that the key factor regulating soil microbiome composition shift was the duration and degree of irreversibility of an agrogenic impact. The key phyla of soil microorganisms were Pseudomonadota, Acidobacteriota, Verrucomicrobiota, Bacteroidota, and Actinobacteriota. The proportion of other phyla was quite variative in soils of different land use. At the same time, all the 30-year-old abandoned soils were more similar to each other than to mature reference soil and 130-year-old soils of monoculture vegetable gardens. Thus, the first factor, regulating soil microbiome composition, is a continuation of soil agrogenic transformation. The second factor is the type of land use if the soil age was equal for fallow territory in the case of one initial podzol soil and one type of landscape. Thus, 30-year-old abandoned soils are intermediate in terms of microbial biodiversity between pristine natural podzols and plaggic podzol. It could be suggested that in the case of secondary involvement of soils in agriculture, the composition of the microbiome may turn to mature soil or to plaggic soil under intensive amelioration.

Economic policy uncertainty and corporate divestitures

AbstractWe examine the impact of economic policy uncertainty (EPU) on the propensity of firms to engage in divestitures. We find that EPU is positively related to the likelihood of divestitures in general and cashflow‐generating divestitures in particular. Consistent with the desire for cash being a driving force behind divestitures, we find that underperforming firms are more likely to engage in cashflow‐increasing divestitures. Firms that do not pay dividends and are relatively more reliant on government funding are also more likely to pursue sell‐offs and carve‐outs when economic uncertainty is elevated. We find no evidence that firms prefer staged divestitures (spin‐offs and carve‐outs) over non‐staged (sell‐offs) when EPU is high. Instead, EPU is positively related to the likelihood of non‐staged divestitures suggesting that firms do not wait until uncertainty is resolved to pursue deals with a high degree of irreversibility. Our findings point to EPU as a motivator for poor‐performing firms to shore up cash during times of EPU.

Uncertainty, credit and investment: Evidence from firm-bank matched data

This paper studies how high uncertainty affects corporate bank loans, addressing the important issue of identification. In times of high uncertainty, firms reduce their credit demand due to delayed investments or a deterioration in credit worthiness. Simultaneously, banks are more exposed to negative shocks to their balance sheet, reducing credit supply. To isolate the uncertainty effect from the credit supply effect, we employ matched bank-firm loan data covering all loans extended by all financial intermediaries to listed firms in Korea, a bank-centered economy. Our empirical results reveal that a failure to control for credit supply leads to overestimating the effect of uncertainty on bank loans. In terms of the transmission channel of uncertainty, we find the evidence of both the real option channel and the financial channel: the negative effect is stronger for firms with a higher degree of investment irreversibility and financially constrained firms. In addition, our findings suggest that larger firms may be predominantly affected by uncertainty shocks through the real option channel rather than the financial channel. In addition, our empirical findings on firm investments align with those on bank loans.

Nuclear Weapons Production Complexes in a Disarmed World

ABSTRACTAny effective nuclear disarmament regime will need to consider how to deal with the infrastructure that supported the development and maintenance of nuclear weapons. Such infrastructure carries within it the seeds for re-armament. This paper presents a framework of potential actions to be applied to facilities within nuclear weapons production complexes in a disarming and a disarmed world. This framework has two axes. The first identifies key capabilities and facilities that are integral to the production of both simple fission weapons and more advanced boosted and thermonuclear weapons. The second axis explores the range of actions that can be taken to constrain nuclear weapons production infrastructure which would either directly or indirectly influence the capacity for future reacquisition of nuclear weapons. In exploring these themes, the paper asks what are the crucial nuclear facilities or processes that are likely to be key in enabling potential re-armament? And what types of actions can be considered to constrain the re-armament potential of these facilities? Considering how to enhance the degree of disarmament irreversibility will entail posing and answering difficult questions on the fate of nuclear weapons complexes, and not just nuclear weapons.

Modeling and Optimization of a Solar-Driven System Coupled with Liquid Dehumidification and Absorption Refrigeration Based on Advanced Exergy and Exergoeconomic Analyses

A novel hybrid system coupled liquid dehumidification with absorption refrigeration driven by solar energy is proposed. Traditional and advanced exergy and exergoeconomic analyses of the system are conducted to ascertain the degree of irreversibility and potential improvement for each component. Based on the advanced exergy and exergoeconomic analyses, the effects of air humidity, segment temperature, and refrigeration temperature on the total exergy destruction and cost rates of the system are obtained. The total avoidable exergy destruction rate, avoidable exergy destruction cost rate, and avoidable investment cost rate of the system are selected as objective functions and optimized by using nondominated sort genetic algorithm-II. The results show that the total exergy destruction rate and the total exergy destruction cost rate reach 262.39 kW and 8.563 $/h, respectively. The generator and regenerator have higher cost rates of the irreversibility overall system, achieving the values 3.536 and 2.430 $/h, respectively. The absorber has the highest investment cost rate in the whole system. The endogenous parts of the exergy destruction and cost rates are much higher than the exogenous parts in the system. Multiobjective optimization results show that optimal values for the total avoidable exergy destruction rate and the exergy destruction cost rate are 50.99 kW and 1.60 $/h, which are 4.15 and 9.14% lower than those calculated by single-objective optimization, respectively. This study provides a potential way to utilize solar energy for dehumidification and refrigeration.

Amide- and Urea-Based Solvents for Li–O2 Batteries. Part I: Experimental Evaluation

Nonaqueous Li–O2 batteries have the potential to aid in the electrification of our society due to their relatively high theoretical energy density. Unfortunately, the technology suffers from large degrees of irreversibility due to the aggressive chemical environment associated with the oxidation of the discharge product lithium peroxide. Herein, we present a study of a range of linear and cyclic amides and ureas as aprotic electrolyte solvents for the Li–O2 battery, some of which show slight increases in reversibility relative to the well-established pseudo-stable glymes, although we find that none provide reversibility necessary to enable a rechargeable system. Using quantitative differential electrochemical mass spectrometry, acid titrations, and isotopic labeling of O2 and carbon in the positive electrode, we provide insight into the degradation pathways for these solvents. In the companion article, we compare our experimental results presented here to solvent decomposition pathways including a Baeyer–Villiger oxidation mechanism.

Micromagnetic Calculations of the Domain Structure of Submicron- and Micron-Sized Magnetite Grains

The evolution of the domain structure (DS) of cubic submicron- and micron-sized magnetite particles has been studied in detail during “cooling” of specimens from the Curie temperature Тс to room temperature Тr followed by their “reheating” to Тс in order to determine the degree of irreversibility of DS changes during heat treatment and their possible effects on the thermoremanent magnetization (TRM) properties. It is shown that typical magnetic configurations in particles up to 2 μm in size have flower or vortex shapes with one or two vortices. A model of the formation of thermoremanent magnetization (TRM) in submicron-sized pseudo-single-domain particles (PSD) is proposed based on an expansion of Neel’s single-domain thermofluctuation model of TRM acquisition. According to the model, the equality of blocking and deblocking temperatures is retained for submicron PSD grains. Consequently, for this magnetic fraction, the Thellier laws of pTRM additivity and independence must also be valid.

Weather pattern dynamics over western Europe under climate change: predictability, information entropy and production

Abstract. The impact of climate change on weather pattern dynamics over the North Atlantic is explored through the lens of the information theory of forced dissipative dynamical systems. The predictability problem is first tackled by investigating the evolution of block entropies on observational time series of weather patterns produced by the Met Office, which reveals that predictability is increasing as a function of time in the observations during the 19th century and beginning of the 20th century, while the trend is reversed at the end of the 20th century and beginning of the 21st century. This feature is also investigated in the 15-member ensemble of the UK Met Office CMIP5 model for the 20th and 21st centuries under two climate change scenarios, revealing a wide range of possible evolutions depending on the realization considered, with an overall decrease in predictability in the 21st century for both scenarios. Lower bounds of the information entropy production are also extracted, providing information on the degree of time asymmetry and irreversibility of the dynamics. The analysis of the UK Met Office model runs suggests that the information entropy production will increase by the end of the 21st century, by a factor of 10 % in the Representative Carbon Pathway RCP2.6 scenario and a factor of 30 %–40 % in the RCP8.5 one, as compared to the beginning of the 20th century. This allows one to make the conjecture that the degree of irreversibility is increasing, and hence heat production and dissipation will also increase under climate change, corroborating earlier findings based on the analysis of the thermodynamic entropy production.

Geometrical Bounds on Irreversibility in Squeezed Thermal Bath.

Irreversible entropy production (IEP) plays an important role in quantum thermodynamic processes. Here, we investigate the geometrical bounds of IEP in nonequilibrium thermodynamics by exemplifying a system coupled to a squeezed thermal bath subject to dissipation and dephasing, respectively. We find that the geometrical bounds of the IEP always shift in a contrary way under dissipation and dephasing, where the lower and upper bounds turning to be tighter occur in the situation of dephasing and dissipation, respectively. However, either under dissipation or under dephasing, we may reduce both the critical time of the IEP itself and the critical time of the bounds for reaching an equilibrium by harvesting the benefits of squeezing effects in which the values of the IEP, quantifying the degree of thermodynamic irreversibility, also become smaller. Therefore, due to the nonequilibrium nature of the squeezed thermal bath, the system-bath interaction energy has a prominent impact on the IEP, leading to tightness of its bounds. Our results are not contradictory with the second law of thermodynamics by involving squeezing of the bath as an available resource, which can improve the performance of quantum thermodynamic devices.

A Crowdfunding Agency Model for Renewables in an Emerging Economy

Mobilizing finance for investment in renewable energy is a challenge for climate change mitigation via fostering the layout of new projects. The challenge becomes critical in emerging or developing economies, mainly because the architecture of financial intermediaries as well as their instruments are shallow and insufficiently developed. The present investigation reviews alternative vehicles of finance applied specifically to renewable energies, that are intermittent, so-called non-dispatchable, and innovation- plus capital-intensive, as compared to conventional sources. The high degree of investment irreversibility and with relatively high uncertainty in the regulatory and wholesale market, calls to carefully design origins of finance at the government, private, and mixed levels. An agency-based theoretical framework is proposed within our ongoing research effort that includes green banks, state banks, bonds, and mainly, crowdfunding, that could be applied to Mexico.