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1 – 10 of 537New non-equilibrium systems theory is a very important theoretical and methodological base of survey and understanding of contemporary economic systems and processes. Equilibrium…
Abstract
Purpose
New non-equilibrium systems theory is a very important theoretical and methodological base of survey and understanding of contemporary economic systems and processes. Equilibrium is considered one of the basic conditions of existence and evolution of natural and social systems, according to scientific literature. Generally speaking, it can be presented as true. But the problem is that classical imagination perceives equilibrium as something real and stable – something more stable than basic condition of evolution of systems. Non-equilibrium state was usually understood as something negative, something destructive and something which has to be eliminated. Non-equilibrium state was understood as an anomaly, as an expression of weakening of system security and as a road to extinction. Thermodynamics comes with an idea that equilibrium is a “short” state of the system, equilibrium is very relative and all systems try to meet it, but they will never reach it. Equilibrium is usually connected with classical science and non-equilibrium state is connected with thermodynamics paradigm, with a new methodology of science. Non-equilibrium state is often seen as a basic condition – as an internal source of system evolution and its activities. Non-equilibrium state is a base of new arrangement of systems. Misunderstanding of contemporary non-equilibrium state theory and new expressions or aspects of dynamic processes can bring about negative impacts on the survey and establishment of new global economic system, e.g. new national and local economic systems. Therefore, the non-equilibrium state theory is a methodological base of new perception and survey of contemporary economic systems.
Design/methodology/approach
A study of non-equilibrium thermodynamics.
Findings
Irreversibility and non-equilibrium, occurring in each process and evolutionary phase of economic systems, are connected with accidents and openness. Openness of systems enables (and causes) diversification toward wider system or environment and penetration of external elements and processes to internal structure of the system. A system like this is more sensitive to external and internal changes. Considering this, it is very important to be aware of the fact that entropy has different behavior in “closed” systems – different from behavior in open systems. Open economic systems communicate with external environment, interact with external systems and they exchange the energy. They consume energy of external environment and penetrate it. Elements, nodes and joints in open systems can communicate, connect and integrate with elements, nodes and joints from external systems. The growth of entropy is “smoother” and equilibrium of the system, its sub-systems and elements proceeds despite the non-equilibrium state of elements of the own system. They have to communicate and exchange the energy with external environment. This is because of the non-equilibrium state.
Originality/value
This is an original thermodynamic approach to the importance of non-equilibrium in the development of economic systems.
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Laurens Weiss and Wolfgang Mathis
The conventional treatment of thermal noise is based on Nyquist’s theorem. This theorem has only been derived for linear, reciprocal (we define “reciprocal networks” as networks…
Abstract
The conventional treatment of thermal noise is based on Nyquist’s theorem. This theorem has only been derived for linear, reciprocal (we define “reciprocal networks” as networks that are built of reciprocal network elements) networks. In this paper a description of thermal noise in reciprocal non‐linear RLC networks is presented. This description is derived from first principles, i.e. from a direct application of non‐equilibrium thermodynamics (irreversible thermodynamics) to electrical networks. As an example, the class of “complete” non‐linear networks is considered. Using the idea of equivalent n‐ports, the theory’s extension to certain classes of transistor circuits should be possible.
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Vipin P. Veetil and Richard E. Wagner
Standard macro theories have the same analytical structure as their micro counterparts. Where micro theories work with equilibrium between supply and demand for particular…
Abstract
Standard macro theories have the same analytical structure as their micro counterparts. Where micro theories work with equilibrium between supply and demand for particular products, macro theories work with equilibrium applied to aggregates of products. This common approach treats the micro–macro relationship as scalable, with macro variables being aggregations over micro variables. In contrast, we pursue a systems-theoretic approach to the micro–macro relationship. This relationship is not scalable and rather entails a disjunction between micro- and macro-levels of theory. While micro phenomena are still susceptible to choice-theoretic analysis, macro phenomena are products of ecological interaction and so entail emergent phenomena. Our alternative approach treats macro theory as a form of systems theory where the behavior of the system has properties that are not reducible to properties of the individual elements within that system. Besides sketching this alternative approach, we examine some of the different insights this approach offers into such topics as unemployment and stabilization.
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James Caton and Richard E. Wagner
Traditional Austrian cycle theory starts from general equilibrium and explains how an expansion of bank credit unmatched by an expansion of saving can create a cycle of…
Abstract
Traditional Austrian cycle theory starts from general equilibrium and explains how an expansion of bank credit unmatched by an expansion of saving can create a cycle of boom-and-bust, and with the bust followed by restoration of normality. In contrast, this paper offers a non-equilibrium reformulation of those earlier Austrian insights, which expands and refocuses the analytical agenda of macro theory. Our key analytical feature is the conceptualization of a macro economy as constituted through an open-ended ecology of plans. Within this framework, macro variables are not primitives but are derivative from micro-level interaction. In turn, the computation of optimizing actions is beset with undecidability. The theory of entrepreneurial choice that is suitable for this analytical framework is based on rule-following or algorithmic choice and not on computational maximization. What results is a macro ecology, the internal operation of which entails natural volatility. What are called policy actions, moreover, operate inside and not outside the ecology, and can create induce volatility within the ecology.
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Chuanqi Liu, Qicheng Sun and Guohua Zhang
Granular materials possess multiscale structures, i.e. micro-scales involving atoms and molecules in a solid particle, meso-scales involving individual particles and their…
Abstract
Purpose
Granular materials possess multiscale structures, i.e. micro-scales involving atoms and molecules in a solid particle, meso-scales involving individual particles and their correlated structure, and macroscopic assembly. Strong and abundant dissipations are exhibited due to mesoscopic unsteady motion of individual grains, and evolution of underlying structures (e.g. force chains, vortex, etc.), which defines the key differences between granular materials and ordinary objects. The purpose of this paper is to introduce the major studies have been conducted in recent two decades.
Design/methodology/approach
The main properties at individual scale are introduced, including the coordination number, pair-correlation function, force and mean stress distribution functions, and the dynamic correlation function. The relationship between meso- and macro-scales is analyzed, such as between contact force and stress, the elastic modulus, and bulk friction in granular flows. At macroscales, conventional engineering models (i.e. elasto-plastic and hypo-plastic ones) are introduced. In particular, the so-called granular hydrodynamics theory, derived from thermodynamics principles, is explained.
Findings
On the basis of recent study the authors conducted, the multiscales (both spatial and temporal) in granular materials are first explained, and a multiscale framework is presented for the mechanics of granular materials.
Originality/value
It would provide a paramount view on the multiscale studies of granular materials.
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Swapnali Makdey, Rajendra Patrikar and Mohammad Farukh Hashmi
A “spin-diode” is the spintronics equivalent of an electrical diode: applying an external magnetic field greater than the limit of spin-diode BT flips the spin-diode between an…
Abstract
Purpose
A “spin-diode” is the spintronics equivalent of an electrical diode: applying an external magnetic field greater than the limit of spin-diode BT flips the spin-diode between an isolating state and a conducting state [1]. While conventional electrical diodes are two-terminal devices with electrical current between the two terminals modulated by an electrical field, these two-terminal magneto resistive devices can generally be referred to as “spin-diodes” in which a magnetic field modulates the electrical current between the two terminals.
Design/methodology/approach
Current modulation and rectification are an important subject of electronics as well as spintronics spin diode is two-terminal magnetoresistive devices in which change in resistance in response to an applied magnetic field; this magnetoresistance occurs due to a variety of phenomena and with varying magnitudes and directions.
Findings
In this paper, an efficient rectifying spin diode is introduced. The resulting spin diode is formed from graphene gallium and indium quantum dots and antimony-doped molybdenum disulfide. Converting an alternating bias voltage to direct current is the main achievement of this model device with an additional profit of rectified spin-current. The non-equilibrium density functional theory with a Monte Carlo sampling method is used to evaluate the flow of electrons and rectification ratio of the system.
Originality/value
The results indicate that spin diode displaying both spin-current and charge-current rectification should be possible and may find practical application in nanoscale devices that combine logic and memory functions.
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Ming‐Cheng Cheng and E.E. Kunhardt
A non‐equilibrium multi‐valley transport model for carriers in compound semiconductor devices has been developed. This macroscopic transport model provides an efficient scheme for…
Abstract
A non‐equilibrium multi‐valley transport model for carriers in compound semiconductor devices has been developed. This macroscopic transport model provides an efficient scheme for device modeling, and can overcome the difficulty in evaluating the relaxation times in multi‐valley conservation equations without a priori assumption of the displaced‐Maxwellian distribution. This model has been successfully applied to electron transport in GaAs subjected to rapidly time‐varying fields. The results have suggested that the macroscopic effective mass of electrons might be strongly dependent on average velocity.
The approach is based on an evolutionary interpretation of the fundamental concepts of cybernetics, general systems theory, information theory, theory of automata, autopoiesis…
Abstract
The approach is based on an evolutionary interpretation of the fundamental concepts of cybernetics, general systems theory, information theory, theory of automata, autopoiesis, etc. In the author's view, this enables us to formulate principles of the evolutionary theory of cybernetic systems which is visualised as the theory of structures, functions and evolution of cybernetic or control systems. This suggests a heuristic idea of cybernetic evolution as the higher stage of negentropic universal evolution of open systems.
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Abstract
Purpose
This paper aims to understand the laser–tissue interaction mechanism during ophthalmic laser surgeries through numerical analysis. The influence of laser parameters and the multipulse technique were investigated.
Design/methodology/approach
The ocular fundus was simplified as a multilayered homogenous medium model. Afterward, the multilayer Monte Carlo method was used to simulate the propagation and energy deposition of laser light, and a local thermal non-equilibrium two-temperature model was established to simulate the temperature variation of chromophores and surrounding tissue with different laser wavelength.
Findings
Through the model, the selective heating of chromophore (melanin and blood vessels) was clearly illustrated: 1) neglecting the laser energy absorbance by blood in the traditional model will cause significant errors in temperature calculation; 2) the non-thermal equilibrium heat transfer model was needed to obtain an accurate description of the thermal process when the dimensionless pulse width (tp*) is <105. For 532 nm Argon laser, the optimize tp* is around 105 and the appropriate energy density is 5 J/cm2; 3) multipulse technique makes the energy more concentrated within the melanin, thereby reducing the thermal damage in surrounding tissue, with most appropriate pulse number and duty cycle is 10 and 1/10.
Originality/value
Taking the blood absorption into account, the different temperature variations of melanin/vessels and surrounding tissue caused by the selective photo-thermolysis were simulated successfully. By understanding the mechanism of laser therapy, laser parameters and multipulse technique are suggested to improve the clinical results.
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