Academic literature on the topic 'Spiral wave'

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Journal articles on the topic "Spiral wave"

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Campos, L. M. B. C., and P. J. S. Gil. "On spiral coordinates with application to wave propagation." Journal of Fluid Mechanics 301 (October 25, 1995): 153–73. http://dx.doi.org/10.1017/s0022112095003843.

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We introduce a possibly new system of orthogonal curvilinear coordinates, whose coordinate curves are logarithmic spirals in the plane, supplemented by a cylindrical coordinate for three dimensions. It is shown that plane spiral coordinates form a oneparameter family, with equal scale factors along the two orthogonal coordinate curves, and constant Christoffel symbols. The equations of magnetohydrodynamics, which include those of fluid mechanics, are written in spiral coordinates and used to find a state of magnetohydrostatic equilibrium under a radial gravity field and spiral magnetic field,
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DELLNITZ, MICHAEL, MARTIN GOLUBITSKY, ANDREAS HOHMANN, and IAN STEWART. "SPIRALS IN SCALAR REACTION–DIFFUSION EQUATIONS." International Journal of Bifurcation and Chaos 05, no. 06 (1995): 1487–501. http://dx.doi.org/10.1142/s0218127495001149.

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Spiral patterns have been observed experimentally, numerically, and theoretically in a variety of systems. It is often believed that these spiral wave patterns can occur only in systems of reaction–diffusion equations. We show, both theoretically (using Hopf bifurcation techniques) and numerically (using both direct simulation and continuation of rotating waves) that spiral wave patterns can appear in a single reaction–diffusion equation [ in u(x, t)] on a disk, if one assumes "spiral" boundary conditions (ur = muθ). Spiral boundary conditions are motivated by assuming that a solution is infin
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BIKTASHEVA, I. V., A. V. HOLDEN, and V. N. BIKTASHEV. "LOCALIZATION OF RESPONSE FUNCTIONS OF SPIRAL WAVES IN THE FITZHUGH–NAGUMO SYSTEM." International Journal of Bifurcation and Chaos 16, no. 05 (2006): 1547–55. http://dx.doi.org/10.1142/s0218127406015490.

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Dynamics of spiral waves in perturbed, e.g. slightly inhomogeneous or subject to a small periodic external force, two-dimensional autowave media can be described asymptotically in terms of Aristotelean dynamics, so that the velocities of the spiral wave drift in space and time are proportional to the forces caused by the perturbation. The forces are defined as a convolution of the perturbation with the spirals Response Functions, which are eigenfunctions of the adjoint linearized problem. In this paper we find numerically the Response Functions of a spiral wave solution in the classic excitabl
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Luo, Jinming, Xingyong Zhang, and Jun Tang. "Complex-Periodic Spiral Waves Induced by Linearly Polarized Electric Field in the Excitable Medium." International Journal of Bifurcation and Chaos 29, no. 05 (2019): 1950071. http://dx.doi.org/10.1142/s0218127419500718.

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Complex-periodic spiral waves are investigated extensively in the oscillatory medium. In this paper, the linearly polarized electric field (LPEF) is employed to induce complex-periodic spiral waves in the excitable medium with abnormal dispersion. As the amplitude of LPEF is increased beyond a threshold, the simple-periodic spiral wave converts into an irregularly complex-periodic one, in which, the local dynamics exhibit several regular spikes followed by one missed spiking period. Furthermore, with the increase of the LPEF amplitude, the missed spiking period follows different numbers of reg
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NIKOLAEV, E. V., V. N. BIKTASHEV, and A. V. HOLDEN. "ON BIFURCATIONS OF SPIRAL WAVES IN THE PLANE." International Journal of Bifurcation and Chaos 09, no. 08 (1999): 1501–16. http://dx.doi.org/10.1142/s021812749900105x.

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We describe the simplest bifurcations of spiral waves in reaction–diffusion systems in the plane and present the list of model systems. One-parameter bifurcations of one-armed spiral waves are fold and Hopf bifurcations. Multiarmed spiral waves may additionally undergo a period-doubling pitchfork bifurcation, when two congruent spiral wave solutions, having the "double" period, branch from the original spiral wave at the bifurcation point.
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LEI, AI ZHONG, QIAN SHU LI, WEIGUO XU, and DAIPING HU. "SPIRAL WAVE MAINTAINED BY NOISE." Fluctuation and Noise Letters 04, no. 03 (2004): L447–452. http://dx.doi.org/10.1142/s0219477504002051.

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The effect of Gaussian white noise on a chemical wavefront is studied in a modified FitzHugn–Nagumo model by applying numerical simulations. A rotating spiral waves can be formed if the medium is excitable enough and the fronts has a free end, when the reaction diffusion system is disturbed by a certain non-zero level noise. It is counterintuitive that noise plays a constructive role in the product and propagation of single spiral waves in this letter. Weak or strong noise will make against the product and propagation of spiral waves. In a certain noise level, spiral wave can be maintained in
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Punacha, Shreyas, Sebastian Berg, Anupama Sebastian, Valentin I. Krinski, Stefan Luther, and T. K. Shajahan. "Spiral wave unpinning facilitated by wave emitting sites in cardiac monolayers." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 475, no. 2230 (2019): 20190420. http://dx.doi.org/10.1098/rspa.2019.0420.

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Rotating spiral waves of electrical activity in the heart can anchor to unexcitable tissue (an obstacle) and become stable pinned waves. A pinned rotating wave can be unpinned either by a local electrical stimulus applied close to the spiral core, or by an electric field pulse that excites the core of a pinned wave independently of its localization. The wave will be unpinned only when the pulse is delivered inside a narrow time interval called the unpinning window (UW) of the spiral. In experiments with cardiac monolayers, we found that other obstacles situated near the pinning centre of the s
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Kuo, Samuel R., and Natalia A. Trayanova. "Action potential morphology heterogeneity in the atrium and its effect on atrial reentry: a two-dimensional and quasi-three-dimensional study." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 364, no. 1843 (2006): 1349–66. http://dx.doi.org/10.1098/rsta.2006.1776.

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Atrial fibrillation (AF) is believed to be perpetuated by recirculating spiral waves. Atrial structures are often characterized with action potentials of varying morphologies; however, the role of the structure-dependent atrial electrophysiological heterogeneity in spiral wave behaviour is not well understood. The purpose of this study is to determine the effect of action potential morphology heterogeneity associated with the major atrial structures in spiral wave maintenance. The present study also focuses on how this effect is further modulated by the presence of the inherent periodicity in
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Lu, Wei, Yu Lan, Rongzhen Guo, Qicheng Zhang, Shichang Li, and Tianfang Zhou. "Spiral Sound Wave Transducer Based on the Longitudinal Vibration." Sensors 18, no. 11 (2018): 3674. http://dx.doi.org/10.3390/s18113674.

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A spiral sound wave transducer comprised of longitudinal vibrating elements has been proposed. This transducer was made from eight uniform radial distributed longitudinal vibrating elements, which could effectively generate low frequency underwater acoustic spiral waves. We discuss the production theory of spiral sound waves, which could be synthesized by two orthogonal acoustic dipoles with a phase difference of 90 degrees. The excitation voltage distribution of the transducer for emitting a spiral sound wave and the measurement method for the transducer is given. Three-dimensional finite ele
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Wang, Chunni, Jun Ma, Bolin Hu, and Wuyin Jin. "Formation of multi-armed spiral waves in neuronal network induced by adjusting ion channel conductance." International Journal of Modern Physics B 29, no. 07 (2015): 1550043. http://dx.doi.org/10.1142/s0217979215500435.

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The Hodgkin–Huxley neuron model is used to describe the local dynamics of nodes in a two-dimensional regular network with nearest-neighbor connections. Multi-armed spiral waves emerge when a group of spiral waves rotate the same core synchronously. Here we have numerically investigated how multi-armed spiral waves are formed in such a system. Under the appropriate conditions, multi-armed spiral waves were able to develop as a result of adjusting the conductance of ion channels of particular neurons in the network. In a realistic neuron model, it can be practiced by blocking potassium of ion ch
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Dissertations / Theses on the topic "Spiral wave"

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Rimal, Nischal. "Impact Localization Using Lamb Wave and Spiral FSAT." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1388672483.

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Caswell, Eric D. "Design and Analysis of Star Spiral with Application to Wideband Arrays with Variable Element Sizes." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/25963.

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This dissertation details the development of the star spiral antenna and demonstrates the advantages of the star spiral when used in a wideband array with variable element sizes. The wideband array with variable element sizes (WAVES) is a multi-octave array that uses different sized circular Archimedean spirals for each octave of frequency coverage. A two-octave WAVES array has been presented in the literature, but a gap in the two-octave frequency coverage exists along the principal axes. The star spiral antenna was developed to eliminate the performance gap in the WAVES array. The star sp
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Xu, Aoxiang 1969. "Computer simulation of reentrant spiral-wave activity in two-dimensional ventricular Myocardium." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27436.

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Acute myocardial ischemia is the main cause of ventricular tachycardia and ventricular fibrillation. Reentrant activity is the most common mechanism of these ventricular arrhythmias, and is often initiated from the border zone between the ischemic and normal tissue. Theoretical studies have suggested that spiral-wave activity may be one form of reentrant arrhythmia. Our study explores the possible relation between spiral-wave activity and ischemia-induced ventricular arrhythmias. We numerically simulate reentrant activity in a two-dimensional sheet of ventricular myocardium which contains an i
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Xu, Aoxiang. "Computer simulation of reentrant spiral-wave activity in two-dimensional ventricular myocardium." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq29811.pdf.

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Boily, Patrick. "Spiral wave dynamics under full Euclidean symmetry-breaking: A dynamical system approach." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/29341.

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Spirals are common in Nature: the snail's shell and the ordering of seeds in the sunflower are amongst the most widely-known occurrences. While these are static, dynamic spirals can also be observed in excitable systems such as heart tissue, retina, certain chemical reactions, slime mold aggregates, flame fronts, etc. The images associated with these spirals are often breathtaking, but spirals have also been linked to cardiac arrhythmias, a potentially fatal heart ailment. In the literature, very specific models depending on the excitable system of interest are used to explain the observed beh
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Heinemann, Tobias. "The dynamics of spiral density waves in turbulent accretion discs." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608944.

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Bramburger, Jason. "On the Existence and Stability of Rotating Wave Solutions to Lattice Dynamical Systems." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36235.

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Rotating wave solutions to evolution equations have been shown to govern many important biological and chemical processes. Much of the rigorous mathematical investigations of rotating waves rely on the model exhibiting a continuous Euclidean symmetry, which is only present in an idealized situation. Here we investigate the existence of rotationally propagating solutions in a discrete spatial setting, in which typical symmetry methods cannot be applied, thus presenting an unique perspective on rotating waves. Our goal in this thesis is to demonstrate the existence and potential stability of rot
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Naknaimueang, Somprasong. "Control of spiral wave dynamics by feedback mechanism via a triangular sensory domain." [S.l.] : [s.n.], 2006. http://diglib.uni-magdeburg.de/Dissertationen/2006/somnaknaimueang.htm.

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Haghighattalab, Armin. "Finite Element Modeling of Spiral Frequency Steerable Acoustic Transducers (FSATs) for guided waves based Structural Health Monitoring of plate-like structures." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.

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Structural Health Monitoring (SHM) is an emerging area of research associated to improvement of maintainability and the safety of aerospace, civil and mechanical infrastructures by means of monitoring and damage detection. Guided wave structural testing method is an approach for health monitoring of plate-like structures using smart material piezoelectric transducers. Among many kinds of transducers, the ones that have beam steering feature can perform more accurate surface interrogation. A frequency steerable acoustic transducer (FSATs) is capable of beam steering by varying the input frequen
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Nakagawa, Harumichi. "Acute Amiodarone Slows Down the Spiral Rotation and Prevents the Wave-Break During Ventricular Tachycardia(RIEM Conference, Ⅱ, 2003)." Research Institute of Environmental Medicine, Nagoya University, 2003. http://hdl.handle.net/2237/7613.

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Books on the topic "Spiral wave"

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Harris, John Maddern. Spiral Grain and Wave Phenomena in Wood Formation. Springer Berlin Heidelberg, 1989.

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Harris, John Maddern. Spiral grain and wave phenomena in wood formation. Springer-Verlag, 1989.

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1916-, Lin C. C., ed. Spiral structure in galaxies: A density wave theory. MIT Press, 1996.

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Harris, John Maddern. Spiral Grain and Wave Phenomena in Wood Formation. Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-73779-4.

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Lubow, Stephen H. Shapes of star-gas waves in spiral galaxies. Space Telescope Science Institute, 1990.

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Lubow, Stephen H. Shapes of star-gas waves in spiral galaxies. Space Telescope Science Institute, 1990.

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Blanchard, Olivier. The wage price spiral. Massachusetts Institute of Technology, Dept. of Economics, 1985.

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Harte, Aidan. Spira mirabilis: Bbook III of the Wave trilogy. Jo Fletcher Books, 2015.

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Walewski, Mateusz. Wage-price spiral in Poland and other postcommunist countries. Center for Social and Economic Research, 1998.

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Kandil, Magda. The wage-price spiral: Industrial country evidence and implications. International Monetary Fund, IMF Institute, 2003.

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Book chapters on the topic "Spiral wave"

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Totz, Jan Frederik. "Spiral Wave Chimera." In Springer Theses. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-11057-4_4.

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Müller, Stefan C., and Theo Plesser. "Spiral Wave Dynamics." In Chemical Waves and Patterns. Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-1156-0_2.

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Harris, John Maddern. "Defining Spiral Grain." In Spiral Grain and Wave Phenomena in Wood Formation. Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-73779-4_1.

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Feitzinger, J. V. "Spiral Arm Waves in Galaxies." In Nonlinear Wave Processes in Excitable Media. Springer US, 1991. http://dx.doi.org/10.1007/978-1-4899-3683-7_33.

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Harris, John Maddern. "Genetics of Spiral Grain." In Spiral Grain and Wave Phenomena in Wood Formation. Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-73779-4_6.

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Skews, B. "Curved shock wave interaction with a spiral vortex." In Shock Waves. Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/978-3-540-27009-6_204.

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Pelcé, P. "Model for Spiral Wave Formation in Excitable Media." In Nonlinear Wave Processes in Excitable Media. Springer US, 1991. http://dx.doi.org/10.1007/978-1-4899-3683-7_16.

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Harris, John Maddern. "Spiral Grain in Relation to the Environment." In Spiral Grain and Wave Phenomena in Wood Formation. Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-73779-4_4.

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Mizushima, Masataka. "Gravitational Wave and Spiral Galaxy (Gravito Radiative Force)." In Frontiers of Fundamental Physics 4. Springer US, 2001. http://dx.doi.org/10.1007/978-1-4615-1339-1_16.

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Kiang, Jean-Fu, and Chi-Yu Peng. "Analysis of Spiral Inductors Embedded in Layered Media." In Novel Technologies for Microwave and Millimeter — Wave Applications. Springer US, 2004. http://dx.doi.org/10.1007/978-1-4757-4156-8_9.

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Conference papers on the topic "Spiral wave"

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Brimis, Apostolos, Konstantinos G. Makris, and Dimitris G. Papazoglou. "Accelerating spiral optical wave-packets." In Frontiers in Optics. OSA, 2019. http://dx.doi.org/10.1364/fio.2019.jtu4a.1.

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Ivanchenko, Igor, Maksym Khruslov, and Nina Popenko. "Spiral antenna for millimeter wave applications." In 2013 21st International Conference on Applied Electromagnetics and Communications (ICECom). IEEE, 2013. http://dx.doi.org/10.1109/icecom.2013.6684712.

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Hooker, J. W., R. K. Arora, W. W. Brey, et al. "Slow-wave analysis of spiral resonators." In 2013 IEEE 14th International Superconductive Electronics Conference (ISEC). IEEE, 2013. http://dx.doi.org/10.1109/isec.2013.6604295.

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Dejun Yu, Weiping Lu, and R. G. Harrison. "Spiral Wave Formation in Nonlinear Diffraction Interaction." In EQEC'96. 1996 European Quantum Electronic Conference. IEEE, 1996. http://dx.doi.org/10.1109/eqec.1996.561553.

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Zheng, Shilie, Zhuofan Zhang, Yu Pan, Xiaofeng Jin, Hao Chi, and Xianmin Zhang. "Plane spiral orbital angular momentum electromagnetic wave." In 2015 Asia-Pacific Microwave Conference (APMC). IEEE, 2015. http://dx.doi.org/10.1109/apmc.2015.7413418.

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GEORGI, M., and N. JANGLE. "SPIRAL WAVE MOTION IN REACTION-DIFFUSION SYSTEMS." In Proceedings of the International Conference on Differential Equations. WORLD SCIENTIFIC, 2005. http://dx.doi.org/10.1142/9789812702067_0108.

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Zangeneh-Nejad, Farzad, and Reza Safian. "Graphene-based archimedean spiral THz antenna." In 2014 Third Conference on Millimeter-Wave and Terahertz Technologies (MMWATT). IEEE, 2014. http://dx.doi.org/10.1109/mmwatt.2014.7057189.

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Chen Chen, Fang Yang, Chenjiang Guo, and Jiadong Xu. "Simulation of Monifilar Archimedean conical spiral antennas." In 2008 International Conference On Microwave and Millimeter Wave Technology. IEEE, 2008. http://dx.doi.org/10.1109/icmmt.2008.4540598.

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Jimenez, Noe, Jean-Philippe Groby, and Vicent Romero-Garcia. "Vortex-sound diffusers using spiral metasurfaces." In 2018 12th International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials). IEEE, 2018. http://dx.doi.org/10.1109/metamaterials.2018.8534047.

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Ishihara, Hajime, and Hiroshi Mifune. "Degenerate four-wave-mixing of spiral-type excitons." In Nonlinear Optics: Materials, Fundamentals and Applications. OSA, 2004. http://dx.doi.org/10.1364/nlo.2004.tuc3.

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Reports on the topic "Spiral wave"

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Krall, J., and C. M. Tang. The Impact of the Three-Wave Instability on the Spiral Line Induction Accelerator. Defense Technical Information Center, 1990. http://dx.doi.org/10.21236/ada229758.

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Hefner, Brian T. Aspect Determination Using a Beacon with a Spiral Wave Front: Modeling and Performance Analysis in Operational Environments. Defense Technical Information Center, 2014. http://dx.doi.org/10.21236/ada626830.

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Blanchard, Olivier. The Wage Price Spiral. National Bureau of Economic Research, 1985. http://dx.doi.org/10.3386/w1771.

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Ji, Qing-hui. Efficacy of extracorporeal shock wave combined spinal core decompression for the treatment of patients with femoral head necrosis: a protocol for systematic review and meta-analysis. INPLASY - International Platform of Registered Systematic Review Protocols, 2020. http://dx.doi.org/10.37766/inplasy2020.4.0092.

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