AN IRREVERSIBILITY PHENOMENA IN ELECTRICAL CONDUCTIVITY OF THE MELTS IN SODIUM IRON PHOSPHATE SYSTEM

Theelectricalresistivityofsodium iron phosphate melts wasinvestigated asa functionoftem peratureand composition. Irreversibility was found in thetemperature dependent electricalresistivityinthe melts withlow Na2 Ocontentduringtheheating andcoolingcycle. Theirre versibility wasreduced withincreasing Na2 Ocontent. Theelectricalresistivity tendedto de creaseslightly withtime. Theelectricalconduction ofthe meltscontainingsimulatedindustry waste wassimilartothatofthe melts withsimilarsodacontent. Thetemperature dependent electricalresistivity and activation energy ofthese melts was discussed using the Motttheory and wascorrelatedtothe Fe(II) contentinthe

Entropy and Irreversibility in Classical and Quantum Mechanics

Review of the irreversibility problem in modern physics with new researches is given. Some characteristics of the Markov chains are specified and the important property of monotonicity of a probability is formulated. Using one thin inequality, the behavior of relative entropy in the classical case is considered. Further we pass to studying of the irreversibility phenomena in quantum problems. By new method is received the Lindblad’s equation and its physical essence is explained. Deep analogy between the classical Markov processes and development described by the Lindblad’s equation is conducted. Using method of comparison of the Lind-blad’s equation with the linear Langevin equation we receive a system of differential equations, which are more general, than the Caldeira-Leggett equation. Here we consider quantum systems without inverse influ-ence on a surrounding background with high temperature. Quantum diffusion of a single particle is consid-ered and possible ways of the permission of the Schr?dinger’s cat paradox and the role of an external world for the phenomena with quantum irreversibility are discussed. In spite of previous opinion we conclude that in the equilibrium environment is not necessary to postulate the processes with collapses of wave functions. Besides, we draw attention to the fact that the Heisenberg’s uncertainty relation does not always mean the restriction is usually the product of the average values of commuting variables. At last, some prospects in the problem of quantum irreversibility are discussed.

Uncertainty,Irreversibility and the Timing Problems of Environmental Policy

Most environmental issues and policy designing are uncertain and irreversible;therefore,the timing of environmental policy implementation becomes especially important.This paper establishes a random dynamic programming model and analyzes the optimal timing problems in environmental policy under uncertain variables.This model results indicate that two variables have a significant impact on the timing of environmental policy implementation and they work in opposite directions:on one hand,the more uncertain the economy is,the higher the cost of policies implementation will be,and consequently the incentive to immediately adopt the policy will be stronger.On the other hand,the higher the uncertainty of the environment is,the stronger the irreversibility of ecological harm caused by pollutants per unit will be.Therefore,the government should implement new environmental policies as early as possible in order to gain more ecological benefits.

About Appearance of the Irreversibility

The inevitability of arising in equations of kinetics and hydrodynamics irreversibility not contained in original equations of classic mechanics is substantiated. It is established that transfer of information about the direction of system evolution from initial conditions to resulting equations is the consequence of losing information about the position of an individual particle in space, which takes place at roughening description. It is shown that the roughening with respect to impact parameters of colliding particles is responsible for appearance of the irreversibility in resulting equations. Direct equations of kinetics and hydrodynamics are the result of roughening distribution functions with respect to impact parameters of particles, which have not yet reached the domain of their interaction. The direct equations are valid for the progressive direction of timing on the time axis pointing from the past to the future. Reverse equations of kinetics and hydrodynamics are the result of roughening distribution functions with respect to impact parameters of particles, which have already left the domain of their interaction. The reverse equations are valid for the progressive direction of timing on the time axis pointing from the future to the past.

Non-Linear Forces and Irreversibility Problem in Classical Mechanics

Restrictions of classical mechanics which take place because of holonomic constraints hypothesis used for obtaining canonical Lagrange equation are analyzed. As it was shown that this hypothesis excludes non-linear terms in the expression for forces which are responsible for energy exchange between different degrees of freedom of a many-body system. An oscillator passing a potential barrier is considered as an example which demonstrated this fact. It was found that the oscillator can pass the barrier even if kinetic energy of its mass center is below the potential barrier’s height due to non-linear terms. This effect is lost because of holonomic constraints hypothesis. We also explained how one can derive a system’s motion equation without the use of holonomic constraints hypothesis. This equation can be used to describe non-linear irreversible processes within the frames of Newton’s laws.

Space-Time Universe versus Energy Driven Time Arrow Universe: Time-Neutrality Confronted with Fundamental Irreversibility

A dynamic interpretation of quantum phenomena based on an energy driven time arrow requires a combined description of matter and information on matter. This information around matter turned out to be gravitation and the fact that a photon is continuously recycled via this information generates an always constant light velocity. These two phenomena, simple consequences of fundamental irreversibility, have mathematically been imposed on empty space for time-neutral spacetime in General Relativity theory. In an irreversible universe such a four-dimensional spacetime would not anymore be required. Another striking difference is the role of time. Clock-time, used in Relativity Theory and found to be relative, is not associated with a generation of changes, being only a scale for measuring changes, based on selected periodic phenomena. The real time in an irreversible world, action time, is the flow of action, as generated by the principle of least action, or, alternatively, the loss of information on the past. In contrast to clock-time, action time is invariant with respect to relativistic transformation and also facilitates self-organization of matter and information. Gravitation as information on matter with the aim of imposing the principle of least action also provides the link between quantum world and cosmology, which Relativity Theory cannot provide. Relevant aspects of both theoretical approaches, with special emphasis on already experimentally verified spacetime phenomena, are critically analysed. While Relativity Theory, which is relying on time-neutral laws, is applied to support a chaotically exploding Big Bang scenario, the fundamentally irreversible universe subject to an energy driven time arrow is characterized by self-organization of energy, matter and information yielding an intelligent and creative “Self-Image” universe, which is able to periodically regenerate itself. Arguments for a fundamentally irreversible energy driven nature include, apart from explaining experimental support for Relativity Theory differently, the simple, straightforward derivation from a dynamically interpreted principle of least action, the elimination of quantum and cosmological paradoxes and the more sensitive and flexible information-technology based (digital) nature of gravitation as compared with the analogue “bent space” gravitation.

Money Circulation Equation Considering Time Irreversibility

The essence of money circulation is that money continues to transfer among economic agents eternally. Based on this recognition, this paper shows a money circulation equation that calculates the quantities of expenditure, revenue, and the end money from the quantity of the beginning money. The beginning money consists of the possession at term beginning, production and being transferred from the outside of the relevant society. The end money consists of the possession at term end, disappearance and transferring to the outside of the relevant society. This equation has a unique solution if and only if each part of the relevant society satisfies the space-time openness condition. Moreover, if money is transferred time irreversibly, each part of the relevant society satisfies the space-time openness condition. Hence, the solvability of the equation is guaranteed by time irreversibility. These solvability conditions are similar to those of the economic input-output equation, but the details are different. An equation resembling our money circulation equation was already shown by Mária Augustinovics, a Hungarian economist. This paper examines the commonalities and differences between our equation and hers. This paper provides the basis for some intended papers by the author.

Solvability of the Economic Input-Output Equation by Time Irreversibility

This paper reinterprets the economic input-output equation as a description of a realized situation without considering decision making. This paper uses the equation that the self-sufficiency rate is added to the Leontief type, and discusses its solvability. The equation has a unique solution if and only if each part of the relevant society satisfies the space-time openness condition. This condition means that commodities which a part of the relevant society possesses are not all inputted to its inside. Moreover, if the process of input and output is time irreversible, each part of the relevant society satisfies the space-time openness condition. Therefore, the solvability of the equation is guaranteed by time irreversibility. This proposition seems to be relevant to the grandfather paradox which is a type of time paradox.

Effects of Detunings on Dynamically Induced Irreversibility in Coherently Driven Systems

Effects of detunings on dynamically induced irreversibility is studied for coherently driven V systems in which there is no conventional source of irreversible population pumping.For atomic barium(γ1/γ2=400>>1,whereγ1 andγ2 are the rates of the spontaneous decay from the excited states 6s6p^(1)P_(1)and 6s6p^(3)P_(1)to the ground state 6s^(2)^(1)S_(0),respectively),the strong irreversibility is found to lead to a maximum inversion of 0.77[only 0.1 in Phys.Rev.Lett.71(1993)4311].The maximum population inversion requires relatively strong Gelds coupled respectively to two transitions,a disparity in two atomic decay rates,and the atom-field detunings of opposite signs.However,it is also shown that even in the cases where two detunings have the same sign,or where two decay rates are equal,population inversion takes place.

Thermodynamics and Irreversibility: From Some Paradoxes to the Efficiency of Effective Engines

The traditional thermodynamic theory explains the reversible phenomena quite well, except that reversible phenomena are rare or even impossible in practice. Here the purpose is to propose an explanation valid for reversible and also irreversible phenomena, irreversibility being common or realistic. It previously exposed points tricky to grasp, as the sign of the work exchange, the adiabatic expansion in vacuum (free expansion) or the transfer of heat between two bodies at the same temperature (isothermal transfer). After having slightly modified the concepts of heat transfer (each body produces heat according to its own temperature) and work (distinguishing external pressure from internal pressure), the previous points are more easily explained. At last, an engine efficiency in case of irreversible transfer is proposed. This paper is focused on the form of thermodynamics, on “explanations”;it does not question on “results” (except the irreversible free expansion of 1845...) which remain unchanged.

In-Depth Energy and Irreversibility Analysis in the Solar Driven Two-Step Thermochemical Water Splitting Cycle for Hydrogen Production

Hydrogen production via a two-step thermochemical cycle based on solar energy has attracted increasing attention.However,the severe irreversible loss causes the low efficiency.To make sense of the irreversibility,an in-depth thermodynamic model for the solar driven two-step thermochemical cycles is proposed.Different from previous literatures solely focusing on the energy loss and irreversibility of devices,this work decouples a complex energy conversion process in three sub-processes,i.e.,reaction,heat transfer and re-radiation,acquiring the cause of irreversible loss.The results from the case study indicate that the main irreversibility caused by inert sweeping gas for decreasing the reduction reaction temperature dominates the cycle efficiency.Decreasing reduction reaction temperature without severe energy penalty of inert sweeping gas is important to reducing this irreversible loss.A favorable performance is achieved by decreasing re-oxidation rate,increasing hydrolysis conversion rate and achieving a thermochemical cycle with a lower equilibrium temperature of reduction reaction at atmosphere pressure.The research clarifies the essence of process irrrversibility in solar thermichemical cycles,and the findings point out the potential to develop efficient solar driven two-step thermochemical cycles for hydrogen production.

The critical current irreversibility of Bi(2223)/Ag tape and its modification

The critical currents of Bi(2223)/Ag tape at magnetic fields up to 2.5T have been measured at different field orientations. The IC values depend on the history of magnetic fields. This phenomenon can be explained in terms of irreversibility of the effective magnetic field caused by the induced persistent current and the screening persistent current. If the mean of the increasing and the decreasing applied field (Hap), defined as the effective field (Hcff), is linearly related to the applied field, i.e. Heff, using Heff instead of Hap, the modified IC(H) curves curves are obtainable.

A comprehensive approach to understanding irreversibility in a turbojet

Regarding interest in and concerns about high efficiency in recent times,an irreversibility assessment of energy conversion systems is significant.Turbojets,a type of energy conversion system,are widely used to provide thrust for aerial vehicles,such as military aircraft missiles,commercial aircraft and so on.From this point of view,the current study aims to introduce a comprehensive irreversibility assessment methodology exemplification for a turbojet.First of all,a basic irreversibility assessment methodology is explained with an application.Following this,a comprehensive assessment is performed.Within this framework,a number of a novel measures are defined by derivations in addition to previously well-known indicators.These measures are beneficial for the decomposition of the irreversibility in a turbojet and its components.At the end of the study,the highest endogenous irreversibility is determined to be in the turbine component of the turbojet engine whereas the highest avoidable irreversibility is found to be in the compressor component of the turbojet engine.The current paper is considered to be of use for researchers and scientists interested in aero-engine performance,thermal engineering and aerospace engineering.

Multiple sclerosis drug repurposing for neuroregeneration

Multiple sclerosis(MS)is an autoimmune disorder of the central nervous system(CNS)and is primarily characterized by immune cell infiltration leading to relapses followed by remission phases and a disease course turning progressive over time with neurodegenerative processes taking over(Amin and Hersh,2023).Of note,beyond relapse-associated worsening early in disease progression independent of relapse activity may arise independently of relapse activity and can occur in all phenotypes.Autoimmune-mediated damage of myelin sheaths and the subsequent loss of mature oligodendrocytes are resulting in impaired axonal integrity,neurodegeneration and accounts for irreversible neuronal damage(Kuhlmann et al.,2023).The current landscape of available disease-modifying therapies comprises mainly immunomodulatory drugs that effectively diminish relapses and slow down progression at the onset form of the disease,namely relapsing MS(RMS).In this regard,a number of drugs have been approved as disease-modifying therapies for MS by US Food and Drug Administration and European Medicines Agencies(Box 1).

IRREVERSIBILITY LINE OF TI_2Ba_2Ca_2Cu_3O_yBULK SUPERCONDUCTOR AND ITS ANOMALY IN LOW FIELDS

where t=T/Tc. Yeshurun et al. studied the irreversibility line ofYBa2Cu3O7-δ single crystal, and obtained a relation similar to expression（1）. The authors also obtained a similar relation from Bi1.7Pb0.3Sr2Ca2Cu3Oy-xFx bulk superconductor, its values of H0 are different above and below 9550 A/m. Research of Rango et al. on Bi1.4Pb0.6Sr2Ca2Cu3O10

A Modified Differential Transform Method (DTM) for Analyzing Irreversibility of Heat Transfer in Flow Through a Moving Plate with Variable Temperature

In this paper, the entropy generation of a flow through a movable plate with variable temperature is studied.Suitable similarity variables are applied to transform the local entropy generation rate to entropy generation number.A modified differential transform method(DTM) with shooting method is used to obtain the similarity solution of the entropy generation. The effects of different parameters(Prandtl number, variable wall temperature) on the irreversibility(such as N_(sh), N_(sf), N_(sx)) are analyzed and discussed. Moreover, it is worth mentioning that DTM is of advantage because its numerical solution is differentiation and integration. Therefore, its analysis result is reliable and high accuracy.

Effectiveness of heat and mass transfer on mixed convective peristaltic motion of nanofluid with irreversibility rate

Entropy generation is one of the key features in analysis as it exhibits irreversibility of the system. Therefore, the present study investigates the entropy generation rate in a mixed convective peristaltic motion of a reactive nanofluid through an asymmetrical divergent channel with heat and mass transfer characteristics. The endorsed nanofluid model holds thermophoresis and Brownian diffusions. Mathematical modeling is configured under the effects of mixed convection, heat generation/absorption and viscous dissipation. A chemical reaction is also introduced for the description of mass transportation. The resulting system of differential equations is numerically tackled by employing the Shooting method. The findings reveal that entropy generation rises by improving the Brownian motion and thermophoresis parameters. The temperature of the nanofluid decreases due to rising buoyancy forces caused by the concentration gradient. The concentration profile increases by increasing the chemical reaction parameter. The velocity increases by enhancing the Brownian motion parameter.

Microstructure investigation of dynamic recrystallization in hard machining:From thermodynamic irreversibility perspective

The drastically changed thermal,mechanical,and chemical energies within the machined surface layer during hard machining tend to initiate microstructural alteration.In this paper,attention is paid to the introduction of thermodynamic potential to unravel the mechanism of microstructure evolution.First,the thermodynamic potential-based model expressed by the Helmholtz free energy was proposed for predicting the microstructure changes of serrated chip and the machined surface layer.Second,the proposed model was implemented into a validated finite element simulation model for cutting operation as a user-defined subroutine.In addition,the predicted irreversible thermodynamic state change in the deformation zones associated with grain size,which was reduced to less than 1 mm from the initial size of 1.5 mm on the machined surface,was provided for an in-depth explanation.The good consistency between the simulated results and experimental data validated the efficacy of the developed model.This research helps to provide further insight into the microstructure alteration during metal cutting.

Sounding Board. The illness as the focus of geriatric medicine

Understanding the difference between illness and disease is a prerequisite to the care of patients affected by incurable disorders.Educated palliation in the absence of substantive information regarding this discrepancy is the art of medicine.Because elderly patients often present with several chronic diseases,many of which are irreversible,cure-oriented physicians caring for the elderly are especially vulnerable to frequent disappointments.

Irreversible electroporation for the management of pancreatic cancer: Current data and future directions

Pancreatic cancer is currently the seventh leading cause of cancer death(4.5%of all cancer deaths)while 80%-90%of the patients suffer from unresectable disease at the time of diagnosis.Prognosis remains poor,with a mean survival up to 15 mo following systemic chemotherapy.Loco-regional thermal ablative techniques are rarely implemented due to the increased risk of thermal injury to the adjacent structures,which can lead to severe adverse events.Irreversible electroporation,a promising novel non-thermal ablative modality,has been recently introduced in clinical practice for the management of inoperable pancreatic cancer as a safer and more effective loco-regional treatment option.Experimental and initial clinical data are optimistic.This review will focus on the basic principles of IRE technology,currently available data,and future directions.