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Denis Evans
Denis James Evans , (born 19 April 1951, Sydney) is an Australian scientist who is an Emeritus Professor at the Australian National University and Honorary Professor at The University of Queensland. He is widely recognised for his contributions to nonequilibrium thermodynamics and nonequilibrium statistical mechanics and the simulation of nonequilibrium fluids. Career Evans graduated with a BSc (Hons 1) in Physics from the University of Sydney in 1972 and a PhD from the Australian National University in 1975. He was a CSIRO Postdoctoral Fellow at the University of Oxford from 1976 to 1977, a Research Fellow at Cornell University from 1977 to 1978 and a Fulbright Fellow at the National Bureau of Standards (Boulder, Colorado, USA) during 1979 and 1980. Evans was appointed as Research Fellow in the Ion Diffusion Unit of the ANU Research School of Physics at the Australian National University in 1979 and joined the ANU Research School of Chemistry in 1982. He was Academic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Australian Chemical Institute
The Royal Australian Chemical Institute (RACI) is both the qualifying body in Australia for professional chemists and a learned society promoting the science and practice of chemistry in all its branches. The RACI hosts conferences, seminars and workshops. It is the professional body for chemistry in Australia, with the ability to award the status of Chartered Chemist (CChem) to suitably qualified candidates. History The RACI was formed as the Australian Chemical Institute in Sydney in September 1917. The driving force was David Orme Masson, professor of chemistry at the University of Melbourne. It was incorporated under the Companies Act in New South Wales in 1923. It was given a royal charter in 1932, but it was not until a supplementary royal charter in 1953 that "Royal" was added to the title of the institute. It moved to Melbourne in 1934. It was incorporated in Victoria in 2000. Since 1993, the institute has had its office at 21 Vale Street, North Melbourne, VIC 3051, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaos Theory
Chaos theory is an interdisciplinary area of scientific study and branch of mathematics focused on underlying patterns and deterministic laws of dynamical systems that are highly sensitive to initial conditions, and were once thought to have completely random states of disorder and irregularities. Chaos theory states that within the apparent randomness of chaotic complex systems, there are underlying patterns, interconnection, constant feedback loops, repetition, self-similarity, fractals, and self-organization. The butterfly effect, an underlying principle of chaos, describes how a small change in one state of a deterministic nonlinear system can result in large differences in a later state (meaning that there is sensitive dependence on initial conditions). A metaphor for this behavior is that a butterfly flapping its wings in Brazil can cause a tornado in Texas. Small differences in initial conditions, such as those due to errors in measurements or due to rounding errors i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffusion
Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical potential. It is possible to diffuse "uphill" from a region of lower concentration to a region of higher concentration, like in spinodal decomposition. The concept of diffusion is widely used in many fields, including physics (particle diffusion), chemistry, biology, sociology, economics, and finance (diffusion of people, ideas, and price values). The central idea of diffusion, however, is common to all of these: a substance or collection undergoing diffusion spreads out from a point or location at which there is a higher concentration of that substance or collection. A gradient is the change in the value of a quantity, for example, concentration, pressure, or temperature with the change in another variable, usually distance. A change in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Flow
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes. Engineers also consider the transfer of mass of differing chemical species (mass transfer in the form of advection), either cold or hot, to achieve heat transfer. While these mechanisms have distinct characteristics, they often occur simultaneously in the same system. Heat conduction, also called diffusion, is the direct microscopic exchanges of kinetic energy of particles (such as molecules) or quasiparticles (such as lattice waves) through the boundary between two systems. When an object is at a different temperature from another body or its surroundings, heat flows so that the body and the surroundings reach the same temperature, at which point they are in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Flow
The term shear flow is used in solid mechanics as well as in fluid dynamics. The expression ''shear flow'' is used to indicate: * a shear stress over a distance in a thin-walled structure (in solid mechanics);Higdon, Ohlsen, Stiles and Weese (1960), ''Mechanics of Materials'', article 4-9 (2nd edition), John Wiley & Sons, Inc., New York. Library of Congress CCN 66-25222 * the flow ''induced'' by a force (in a fluid). In solid mechanics For thin-walled profiles, such as that through a beam or semi-monocoque structure, the shear stress distribution through the thickness can be neglected. Furthermore, there is no shear stress in the direction normal to the wall, only parallel. In these instances, it can be useful to express internal shear stress as shear flow, which is found as the shear stress multiplied by the thickness of the section. An equivalent definition for shear flow is the shear force ''V'' per unit length of the perimeter around a thin-walled section. Shear flow has the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Dynamics
Molecular dynamics (MD) is a computer simulation method for analyzing the physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a fixed period of time, giving a view of the dynamic "evolution" of the system. In the most common version, the trajectories of atoms and molecules are determined by numerically solving Newton's equations of motion for a system of interacting particles, where forces between the particles and their potential energies are often calculated using interatomic potentials or molecular mechanical force fields. The method is applied mostly in chemical physics, materials science, and biophysics. Because molecular systems typically consist of a vast number of particles, it is impossible to determine the properties of such complex systems analytically; MD simulation circumvents this problem by using numerical methods. However, long MD simulations are mathematically ill-conditioned, generating cumulative errors in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second Law Of Thermodynamics
The second law of thermodynamics is a physical law based on universal experience concerning heat and Energy transformation, energy interconversions. One simple statement of the law is that heat always moves from hotter objects to colder objects (or "downhill"), unless energy in some form is supplied to reverse the direction of heat flow. Another definition is: "Not all heat energy can be converted into Work (thermodynamics), work in a cyclic process."Young, H. D; Freedman, R. A. (2004). ''University Physics'', 11th edition. Pearson. p. 764. The second law of thermodynamics in other versions establishes the concept of entropy as a physical property of a thermodynamic system. It can be used to predict whether processes are forbidden despite obeying the requirement of conservation of energy as expressed in the first law of thermodynamics and provides necessary criteria for spontaneous processes. The second law may be formulated by the observation that the entropy of isolated systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluctuation Theorem
The fluctuation theorem (FT), which originated from statistical mechanics, deals with the relative probability that the entropy of a system which is currently away from thermodynamic equilibrium (i.e., maximum entropy) will increase or decrease over a given amount of time. While the second law of thermodynamics predicts that the entropy of an isolated system should tend to increase until it reaches equilibrium, it became apparent after the discovery of statistical mechanics that the second law is only a statistical one, suggesting that there should always be some nonzero probability that the entropy of an isolated system might spontaneously ''decrease''; the fluctuation theorem precisely quantifies this probability. Statement Roughly, the fluctuation theorem relates to the probability distribution of the time-averaged irreversible entropy production, denoted \overline_t. The theorem states that, in systems away from equilibrium over a finite time ''t'', the ratio between the probab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Australian National University
The Australian National University (ANU) is a public research university located in Canberra, the capital of Australia. Its main campus in Acton encompasses seven teaching and research colleges, in addition to several national academies and institutes. ANU is regarded as one of the world's leading universities, and is ranked as the number one university in Australia and the Southern Hemisphere by the 2022 QS World University Rankings and second in Australia in the ''Times Higher Education'' rankings. Compared to other universities in the world, it is ranked 27th by the 2022 QS World University Rankings, and equal 54th by the 2022 ''Times Higher Education''. In 2021, ANU is ranked 20th (1st in Australia) by the Global Employability University Ranking and Survey (GEURS). Established in 1946, ANU is the only university to have been created by the Parliament of Australia. It traces its origins to Canberra University College, which was established in 1929 and was integrated into A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian Academy Of Science
The Australian Academy of Science was founded in 1954 by a group of distinguished Australians, including Australian Fellows of the Royal Society of London. The first president was Sir Mark Oliphant. The academy is modelled after the Royal Society and operates under a Royal Charter; as such, it is an independent body, but it has government endorsement. The Academy Secretariat is in Canberra, at the Shine Dome. The objectives of the academy are to promote science and science education through a wide range of activities. It has defined four major program areas: :* Recognition of outstanding contributions to science :* Education and public awareness :* Science policy :* International relations The academy also runs the 22 National Committees for Science which provide a forum to discuss issues relevant to all the scientific disciplines in Australia. Origins The Australian National Research Council (ANRC) was established in 1919 for the purpose of representing Australia on the In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
