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"Arthur Brooks Harris, called Brooks Harris, (born 25 March 1935)biographical information from American Men and Women of Science, Thomson Gale 2004 is an American physicist. Biography Harris was born in Boston, Massachusetts and studied at Harvard University with bachelor's degree in 1956, master's degree in 1959, and PhD in experimental solid state physics from Horst Meyer in 1962. Harris was in 1961/62 at Duke University to complete his doctoral thesis with Meyer and then was an instructor there from 1962 to 1964. During 1961–1964 at Duke University Harris retrained himself as a theorist in condensed matter physics and then spent the academic year 1964/65 as a researcher working with John Hubbard in the UK at the Atomic Energy Research Establishment (Harwell Laboratory) near Harwell, Oxfordshire. At the University of Pennsylvania, Harris became in 1965 an assistant professor and in 1977 a full professor, continuing there until his retirement as professor emeritus. He was a visiting professor at University of British Columbia in 1976, at the University of Oxford in 1973, 1986, and 1994, at Tel Aviv University in 1987 and 1995, and at McMaster University in 2005. He was visiting scientist at Sandia National Laboratories in 1974 and at the National Institute of Standards and Technology (NIST) in 2002. In 2007 he received the Lars Onsager Prize for his contributions to the statistical physics of disordered systems, especially for the development of the Harris criterion. From 1967 to 1969 he was Sloan Fellow and in 1972/73 a Guggenheim Fellow. In 1989 he was elected a Fellow of the American Physical Society. Harris has been married to Peggy since 1958 and has three children, eight grandchildren, and one great grandson, Jimmy. Research Upon receiving the Lars Onsager Prize, Harris wrote in 2007: He has also collaborated in theoretical condensed matter physics with R. J. Birgeneau (MIT), J. Yeomans (Oxford), R. D. Kamien (Penn), C. Broholm (Johns Hopkins), and A. Ramirez (Bell Labs). In 1973 he developed at Oxford the Harris criterion, which indicates the extent to which the critical exponents of a phase transition are modified by a small amount of randomness (e.g., defects, dislocations, or impurities). Such impurities "smear" the phase transition and lead to local variations in the transition temperature. Let d denote the spatial dimension of the system and let u denote the critical exponent of correlation length. The Harris criterion states that if : u \geq \frac {2} {d} the impurities do not affect the critical behavior (so that the critical behavior is then stable against the random interference). For example, in the classical three-dimensional Heisenberg model u = 0 {.} 698 and thus the Harris criterion is satisfied, while the three-dimensional Ising model has u = 0 {. } 627 and thus does not satisfy the criterion ( d = 3 ). Selected publications * "Effect of Random Defects on the Critical Behaviour of Ising Models,” A. Brooks Harris, J. Phys. C 7, 1671–1692 (1974). * “Single-Particle Excitations in Narrow Energy Bands,” A. Brooks Harris and Robert V. Lange, Phys. Rev. 157, 295–314 (1967). * “Renormalization-Group Approach to the Critical Behavior of Random-Spin Models,” A. Brooks Harris and T. C. Lubensky, Phys. Rev. Lett. 33, 1540–1543 (1974). * “Comment on “Orientational Ordering Transition in Solid C60”," Ravi Sachidanandam and A. B. Harris, Phys. Rev. Lett. 67, 1467–1467 (1991). * “Possible Néel Orderings of the Kagomé Antiferromagnet,” A. B. Harris, C. Kallin, and A. J. Berlinsky, Phys. Rev. B 45, 2899–2919 (1992). * “Mean Field Theory of the Orientational Properties of (J = 1) Molecules on the Surface of Grafoil,” A. B. Harris and A. J. Berlinsky, Can. J. Phys. 7, 1852–1868 (1979). * “Molecular Chirality and Chiral Parameters,” A. B. Harris, R. D. Kamien, and T. C. Lubensky, Rev. Mod. Phys. 71, 1745–1757 (1999). * “Magnetically Driven Ferroelectric Order in Ni3V2O8,” G. Lawes, A. B. Harris, T. Kimura, N. Rogado, R. J. Cava, A. Aharony, O. Entin-Wohlman, T. Yildirim, M. Kenzelmann, C. Broholm, and A. P. Ramirez, Phys. Rev. Lett. 95, 087205 (2005). * “Anisotropic Spin Hamiltonians due to Spin-Orbit and Coulomb Exchange Interactions,” T. Yildirim, A. B. Harris, Amnon Aharony, and O. Entin-Wohlman, Phys. Rev. B 52, 10239–10267 (1995). * “Observation of the Pair Interaction Between Ortho Molecules in Solid H2,” A. Brooks Harris, Larry I. Amstutz, Horst Meyer, and Samuel M. Myers, Phys. Rev. 175, 603–609 (1968). References 1935 births Living people Fellows of the American Physical Society Sloan Research Fellows Harvard University alumni University of Pennsylvania faculty 20th-century American physicists 21st-century American physicists "
"Tropidia viridifusca, commonly known as the dark crown orchid, is an evergreen, terrestrial plant with thin, pleated, dark green leaves on a thin, upright stem with up to seven green and brown flowers crowded on a short flowering stem on top. It is only known from three Pacific Islands near Australia. Description Tropidia viridifusca is an evergreen, terrestrial herb with thin but tough, upright stems tall with between four and seven thin, pleated, dark green leaves long and wide. The leaves have three prominent veins. Above the leaves is a flowering stem about long with between two and seven green and brown flowers. The flowers open widely and are long and wide. The sepal are long and wide with the lateral sepals spreading widely apart from each other. The petals are long and wide. The labellum is long, about wide and brown to almost black with a thick pouch at its base. Flowering occurs between December and January. Taxonomy and naming Tropidia viridifusca was first formally described in 1929 by Friedrich Wilhelm Ludwig Kraenzlin and the description was published in Vierteljahrsschrift der Naturforschenden Gesellschaft in Zürich. The specific epithet (viridifusca) is derived from the Latin words viridis meaning "green" and fuscus meaning "dusky" or "tawny". Distribution and habitat The dark crown is only known from Grande Terre in New Caledonia, Vanuatu and Norfolk Island where it grows on slopes in shady forest. References viridifusca Plants described in 1929 Terrestrial orchids Orchids of Australia Orchids of Oceania "
"In fluid dynamics, Blasius theorem states that Lamb, H. (1993). Hydrodynamics. Cambridge university press. pp. 91Milne-Thomson, L. M. (1949). Theoretical hydrodynamics (Vol. 8, No. 00). London: Macmillan.Acheson, D. J. (1991). Elementary fluid dynamics. the force experienced by a two-dimensional fixed body in a steady irrotational flow is given by :F_x-iF_y = \frac{i\rho}{2} \oint_C \left(\frac{\mathrm{d}w}{\mathrm{d}z}\right)^2\mathrm{d}z and the moment about the origin experienced by the body is given by :M=\Re\left\\{-\frac{\rho}{2}\oint_C z \left(\frac{\mathrm{d}w}{\mathrm{d}z}\right)^2\mathrm{d}z\right\\}. Here, *(F_x,F_y) is the force acting on the body, *\rho is the density of the fluid, *C is the contour flush around the body, *w=\phi+ i\psi is the complex potential (\phi is the velocity potential, \psi is the stream function), *{\mathrm{d}w}/{\mathrm{d}z} = u_x-i u_y is the complex velocity ((u_x,u_y) is the velocity vector), *z=x+iy is the complex variable ((x,y) is the position vector), and *M is the moment about the coordinate origin acting on the body. The first formula is sometimes called Blasius–Chaplygin formula. The theorem is named after Paul Richard Heinrich Blasius, who derived it in 1911.Blasius, H. (1911). Mitteilung zur Abhandlung über: Funktionstheoretische Methoden in der Hydrodynamik. Zeitschrift für Mathematik und Physik, 59, 43-44. The Kutta–Joukowski theorem directly follows from this theorem. References Fluid dynamics "