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THE LOGARITHMIC SPIRAL AND ITS SPHERICAL COUNTERPART
Journal of Industrial Design and Engineering Graphics, 2020 Logarithmic spirals are isogonal trajectories of pencils of lines. From a series of geometric consequences, we pick out a few which are relevant for kinematics: When a logarithmic spiral rolls on a line, its asymptotic point traces a straight line. Hence,
Hellmuth Stachel +2 more
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Grand Design and Flocculent Spirals in the Spitzer Survey of Stellar Structure in Galaxies (S4G) [PDF]
, 2011 Spiral arm properties of 46 galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S4G) were measured at 3.6mu, where extinction is small and the old stars dominate.
Albert Bosma +73 more
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Cold gas and star formation in a merging galaxy sequence [PDF]
, 2000 We explore the evolution of the cold gas and star-formation activity during galaxy interactions, using a merging galaxy sequence comprising both pre- and post-mergers.
Forbes, Duncan A. +2 more
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Factoring the logarithmic spiral
Inventiones Mathematicae, 1988 If f is a K-quasiconformal homeomorphism of Jordan domains in the plane, then for any given \(c>1\), f is equal to some composition of \(N1\). Then it is easy to show that \(s_ k\) is an L-quasi-isometry, i.e., \[ (1/L)| p-q| \leq | s_ k(p)-s_ k(q)| \leq L| p-q|,\quad \forall p,q\in \bar D^ 2.
He, Zheng-Xu, Freedman, Michael H.
openaire +1 more source
The Dark Matter Distribution in Disk Galaxies [PDF]
, 2000 We use high-quality optical rotation curves of 9 low-luminosity disk galaxies to obtain the velocity profile of the surrounding dark matter halos. We find that they increase linearly with radius at least out to the stellar disk edge, implying that, over ...
Borriello, A., Salucci, P.
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Stability of generalized Newton difference equations
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2012 In the paper we discuss a stability in the sense of the generalized Hyers-Ulam-Rassias for functional equations Δn(p, c)φ(x) = h(x), which is called generalized Newton difference equations, and give a sufficient condition of the generalized Hyers-Ulam ...
Wang Zhihua, Shi Yong-Guo
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Eclipse maps of spiral shocks in the accretion disc of IP Pegasi in outburst [PDF]
, 2000 Eclipse lightcurves of the dwarf nova IP Peg during the November 1996 outburst are analysed with eclipse mapping techniques to constrain the location and investigate the spatial structure of the spiral shocks observed in the Doppler tomograms (Harlaftis ...
Baptista, Raymundo +2 more
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Aerospace, 2015 Research on shock wave mitigation in channels has been a topic of much attention in the shock wave community. One approach to attenuate an incident shock wave is to use obstacles of various geometries arranged in different patterns. This work is inspired
Qian Wan, Veronica Eliasson
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Spiral cracks in drying precipitates
, 2002 We investigate the formation of spiral crack patterns during the desiccation of thin layers of precipitates in contact with a substrate. This symmetry-breaking fracturing mode is found to arise naturally not from torsion forces, but from a propagating ...
A. E. Tucker +20 more
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A “Logarithmic Spiral” in the Brain: Images of an Intracranial Dermoid Cyst
Brain Science Advances, 2016 A logarithmic spiral is a self-similar spiral curve, which often appears in nature, e.g., mollusk shells. In the normal tissues of the human body, the cochlea is also an approximate logarithmic spiral. However, approximate logarithmic spirals are rarely,
Meiqing Lou, Yaodong Zhao
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