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Dissipative Structure
A dissipative system is a thermodynamically open system which is operating out of, and often far from, thermodynamic equilibrium in an environment with which it exchanges energy and matter. A tornado may be thought of as a dissipative system. Dissipative systems stand in contrast to conservative systems. A dissipative structure is a dissipative system that has a dynamical regime that is in some sense in a reproducible steady state. This reproducible steady state may be reached by natural evolution of the system, by artifice, or by a combination of these two. Overview A dissipative structure is characterized by the spontaneous appearance of symmetry breaking ( anisotropy) and the formation of complex, sometimes chaotic, structures where interacting particles exhibit long range correlations. Examples in everyday life include convection, turbulent flow, cyclones, hurricanes and living organisms. Less common examples include lasers, Bénard cells, droplet cluster, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open System (systems Theory)
An open system is a system that has external interactions. Such interactions can take the form of information, energy, or material transfers into or out of the system boundary, depending on the discipline which defines the concept. An open system is contrasted with the concept of an isolated system which exchanges neither energy, matter, nor information with its environment. An open system is also known as a flow system. The concept of an open system was formalized within a framework that enabled one to interrelate the theory of the organism, thermodynamics, and evolutionary theory. This concept was expanded upon with the advent of information theory and subsequently systems theory. Today the concept has its applications in the natural and social sciences. In the natural sciences an open system is one whose border is permeable to both energy and mass. By contrast, a closed system is permeable to energy but not to matter. The definition of an open system assumes that there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Droplet Cluster
Droplet cluster is a self-assembled levitating monolayer of microdroplets usually arranged into a hexagonally ordered structure over a locally heated thin (about 1 mm) layer of water. The droplet cluster is typologically similar to colloidal crystals. The phenomenon was observed for the first time in 2004, and it has been extensively studied after that. Growing condensing droplets with a typical diameter of 0.01 mm – 0.2 mm levitate at an equilibrium height, where their weight is equilibrated by the drag force of the ascending air-vapor jet rising over the heated spot. At the same time, the droplets are dragged towards the center of the heated spot; however, they do not merge, forming an ordered hexagonal (densest packed) pattern due to an aerodynamic repulsive pressure force from gas flow between the droplets. The spot is usually heated by a laser beam or another source of heat to 60 °C – 95 °C, although the phenomenon was observed also at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onsager Reciprocal Relations
In thermodynamics, the Onsager reciprocal relations express the equality of certain ratios between flows and forces in thermodynamic systems out of equilibrium, but where a notion of local equilibrium exists. "Reciprocal relations" occur between different pairs of forces and flows in a variety of physical systems. For example, consider fluid systems described in terms of temperature, matter density, and pressure. In this class of systems, it is known that temperature differences lead to heat flows from the warmer to the colder parts of the system; similarly, pressure differences will lead to matter flow from high-pressure to low-pressure regions. What is remarkable is the observation that, when both pressure and temperature vary, temperature differences at constant pressure can cause matter flow (as in convection) and pressure differences at constant temperature can cause heat flow. Perhaps surprisingly, the heat flow per unit of pressure difference and the density (matter) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extremal Principles In Non-equilibrium Thermodynamics
Energy dissipation and entropy production extremal principles are ideas developed within non-equilibrium thermodynamics that attempt to predict the likely steady states and dynamical structures that a physical system might show. The search for extremum principles for non-equilibrium thermodynamics follows their successful use in other branches of physics.Ziegler, H., (1983). ''An Introduction to Thermomechanics'', North-Holland, Amsterdam, According to Kondepudi (2008), and to Grandy (2008),Grandy, W.T., Jr (2008). ''Entropy and the Time Evolution of Macroscopic Systems'', Oxford University Press, Oxford, . there is no general rule that provides an extremum principle that governs the evolution of a far-from-equilibrium system to a steady state. According to Glansdorff and Prigogine (1971, page 16), irreversible processes usually are not governed by global extremal principles because description of their evolution requires differential equations which are not self-adjoint, but loca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nobel Prize In Chemistry
) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then "MDCCCXXXIII" above, followed by (smaller) "OB•" then "MDCCCXCVI" below. , awarded_for = Outstanding contributions in chemistry , presenter = Royal Swedish Academy of Sciences , location = Stockholm, Sweden , reward = 9 million SEK (2017) , year = 1901 , holder = Carolyn R. Bertozzi, Morten P. Meldal and Karl Barry Sharpless (2022) , most_awards = Frederick Sanger and Karl Barry Sharpless (2) , website nobelprize.org, previous = 2021 , year2=2022, main= 2022, next= 2023 The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, award ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
