Download or read book Investigating Transitions in Planetary Dynamo Models written by Krista Marie Soderlund and published by . This book was released on 2011 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Planetary Dynamo Models written by Girija Dharmaraj and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lectures on Solar and Planetary Dynamos written by M. R. E. Proctor and published by Cambridge University Press. This book was released on 1994-12-08 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprised of lectures for an intensive course held at the Newton Institute in Cambridge, as part of a NATO Advanced Study Institute, the topics covered within this volume include planetary and solar dynamos, fast dynamos, and the use of symmetry principles to derive evolution equations.
Download or read book Earth s Core Boundary and Geodynamos written by D. R. Fearn and published by CRC Press. This book was released on 1989 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains papers given at a workshop on the earth's core boundary and geodynamos held at Liblice Castle, Czechoslovakia in 1988.
Download or read book The Explicit Body in Performance written by Rebecca Schneider and published by Routledge. This book was released on 2013-06-17 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Explicit Body in Performance interrogates the avant-garde precedents and theoretical terrain that combined to produce feminist performance art. Among the many artists discussed are: * Carolle Schneemann * Annie Sprinkle * Karen Finley * Robbie McCauley * Ana Mendieta * Ann Magnuson * Sandra Bernhard * Spiderwoman Rebecca Schneider tackles topics ranging across the 'post-porn modernist movement', New Right censorship, commodity fetishism, perspectival vision, and primitivism. Employing diverse critical theories from Benjamin to Lacan to postcolonial and queer theory, Schneider analyses artistic and pop cultural depictions of the explicit body in late commodity capitalism. The Explicit Body in Performance is complemented by extensive photographic illustrations and artistic productions of postmodern feminist practitioners. The book is a fascinating exploration of how these artists have wrestled with the representational structures of desire.
Download or read book Investigation of Transitions from Order to Chaos in Dynamical Systems written by and published by . This book was released on 1992 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report briefly discusses the following topics on chaotic systems; numerical investigations of fast dynamo problem for stationary space-periodic flows with chaotic streamlines; analytical and numerical investigations of magnetic field generation by conducting flows with finite resistivity; and emittance growth in charged particle beams.
Download or read book Investigation of Transitions from Order to Chaos in Dynamical Systems Final Technical Report Period Ending May 31 1996 written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been recently conjectured that chaotic flows in conductive fluids can generate fast dynamos, where the magnetic field increases exponentially in time such processes could be responsible for the generation of solar and terrestrial magnetic fields. The author studied realistic flows, like those arising from the Rayleigh Benard instability. First the flow was studied computationally as well as analytically, to give a clear description of its properties, relevant ranges of parameter and regions of chaotic flow. Once this task was accomplished computational studies were carried out to see if such flows are capable of fast dynamo action. In addition, the author carried out preliminary investigations on other applications of chaotic dynamics, like emittance growth in electron beams, and the relationship between stochastic webs and percolation theory.
Download or read book Literature 1981 Part 2 written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-04-18 with total page 803 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigations of Convective Turbulence in Planetary Cores written by Emily Kate Hawkins and published by . This book was released on 2020 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The magnetic fields of planets and other bodies are created and sustained due to the turbulent motions of an internal fluid layer, a process known as dynamo action. Forward models are required to characterize the dynamics of rotating convective turbulence driving dynamo action due to the inability to obtain direct measurements of the internal fluid layers of planetary bodies. The characteristic flow velocities and length scales of dynamo systems remain poorly constrained due to the difficulty of modeling realistic planetary core conditions. Thus, the goal of this dissertation is to explore these key properties of core-style convection. To do so, I have conducted novel experiments aimed to better quantify the features of quasi- geostrophic turbulence using the UCLA large-scale rotating convection device, 'NoMag'. I have completed a systematic study to simultaneously measure the heat transfer and bulk velocities of different rotating convective regimes at some of the most extreme laboratory conditions possible to date. The study of heat transfer is employed in most forward models of core-style convection. In laboratory experiments in particular, due to the relative difficulty of collecting velocity measurements, those of heat transfer alone are assessed, the dynamics of which are assumed to describe the the bulk velocity dynamics of the system. On the contrary, I utilize laser doppler velocimetry to obtain measurements of bulk velocities concurrently with the collection of temperature measurements for the characterization of system heat transfer. I find that heat transfer behavior is consistent with the results of past studies and is largely controlled by boundary layer dynamics. I further find that velocity behaviors do not directly coincide with heat transfer behaviors in the parameter space studied. Instead, I show that a dynamical flow regime of quasi-geostrophic turbulence relevant to core flows is robustly reached, suggesting that it is possible to access realistic bulk dynamics in models that remain far from planetary core conditions. Using the results of this study, I estimate the characteristic length scales of the flows of each experiment. These estimates from my data are compared with length scale estimates of numerous numerical models of planetary core convection. I conclude from this meta-analysis of forwards models that all evidence to date suggests that the theorized characteristic length scales of planetary dynamo systems co-scale with one another and are thus non-separable. In two other studies that comprise the remainder of this dissertation, I further examine the applicability of laboratory models towards planetary settings. An experimental study on the influence of centrifugal buoyancy on rotating convection in water and in liquid metal was completed, where results agree with the recent numerical work of Horn and Aurnou (2018). It is found that the transition from Coriolis to centrifugally dominated convection depends on the strength of the centrifugal buoyancy relative to the gravitational buoyancy and the geometry of the cylinder in which experiments are conducted. These results are useful to ensure that the regime of rotating convection explored in a given experiment is relevant to planetary core flows, i.e. not centrifugally dominated. Separately, I conducted a series of spin up experiments with well-established theory to calibrate the NoMag apparatus and its measuring components. Further, the results from spin up experiments conducted with rough boundaries might have geophysical implications for the possible viscous coupling at Earth's core mantle boundary, as well as turbulent mixing in the global ocean. The results of the studies presented in this dissertation clarify the relevance of long theorized and poorly tested dynamic length and velocity scalings of planetary core flows. Flows that are quasi-geostrophically turbulent are robustly observed in the laboratory data collected in this dissertation. The need for next generation models of planetary core flows is motivated by the results of the work herein. In particular, studies in which the characteristic length scales of core-style flows are directly quantified will undoubtedly enhance our understanding of the multi-scale turbulent physics driving planetary dynamo systems.
Download or read book Experimental and Numerical Studies of Mechanically and Convectively Driven Turbulence in Planetary Interiors written by Alexander Michael Grannan and published by . This book was released on 2017 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy for driving turbulent flows in planetary fluid layers comes from a combination of thermocompositional sources and the motion of the boundary in contact with the fluid through mechanisms like precessional, tidal, and librational forcing. Characterizing the resulting turbulent fluid motions are necessary for understanding many aspects of the planet's dynamics and evolution including the generation of magnetic fields in the electrically conducting fluid layers and dissipation in the oceans. Although such flows are strongly inertial they are also strongly influenced by the Coriolis force whose source is in the rotation of the body and tends to constrain the inertial effects and provide support for fluid instabilities that might in-turn generate turbulence. Furthermore, the magnetic fields generated by the electrically conducting fluids act back on the fluid through the Lorentz force that also tends to constrain the flow. The goal of this dissertation is to investigate the characteristics of turbulent flows under the influence of mechanical, convective, rotational and magnetic forcing. In order to investigate the response of the fluid to mechanical forcing, I have modified a unique set of laboratory experiments that allows me to quantify the generation of turbulence driven by the periodic oscillations of the fluid containing boundary through tides and libration. These laboratory experiments replicate the fundamental ingredients found in planetary environments and are necessary for the excitation of instabilities that drive the turbulent fluid motions. For librational forcing, a rigid ellipsoidal container and ellipsoidal shell of isothermal unstratified fluid is made to rotate with a superimposed oscillation while, for tidal forcing, an elastic ellipsoidal container of isothermal unstratified fluid is made to rotate while an independently rotating perturbance also flexes the elastic container. By varying the strength and frequencies of these oscillations the characteristics of the resulting turbulence are investigated using meridional views to identify the dominate modes and spatial location of the turbulence. For the first time, measurements of the velocity in the equatorial plane are coupled with high resolution numerical simulations of the full flow field in identical geometry to characterize the instability mechanism, energy deposited into the fluid layer, and long-term evolution of the flow. The velocities determined through laboratory and numerical simulations when extrapolated to planets allow me to argue that that the dynamics of mechanical forcing in low viscosity fluids may an important role as new and potentially large source of dissipation in planetary interiors. To study convective forcing, I have modified and performed a set of rotating and non-rotating hydrodynamic convection experiments using water as well as rotating and non-rotating magnetohydrodynamic convection in gallium. These studies are performed in a cylindrical geometry representing a model of high latitude planetary core style convection wherein the axis of rotation and gravity are aligned. For the studies using water, the steady columns that are characteristic of rotating convection and present in the dynamo models are likely to destabilize at the more extreme planetary parameters giving way to transitions to more complex styles of rotating turbulent flow. In the studies of liquid metal where the viscosity is lower, the onset of rotating convection occurs through oscillatory columnar convection well below the onset of steady columns. Such oscillatory modes are not represented at the parameters used by current dynamo models. Furthermore a suite of laboratory experiments shows that the imposition of rotational forces and magnetic forces both separately and together generate zeroeth order flow transitions that change the fundamental convective modes and heat transfer. Such regimes are more easily accessible to laboratory experiments then to numerical simulations but demonstrate the need for a new generation of dynamo simulations capable of including the fundamental properties of liquid metals as are relevant for understanding the dynamics of planetary interiors.
Download or read book Saturn in the 21st Century written by Kevin H. Baines and published by Cambridge University Press. This book was released on 2018-12-06 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed overview of Saturn's formation, evolution and structure written by eminent planetary scientists involved in the Cassini Orbiter mission.
Download or read book Interior Structure of the Earth and Planets written by Vladimir Naumovich Zharkov and published by CRC Press. This book was released on 1986 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides a solid introduction to advanced geophysics. Part I focuses on the interior structure of the earth, featuring a large section on plate tectonics and discussing such problems as the source mechanisms of earthquakes, tides, the rheology of the crust and mantle and the evolution of the lunar orbit. Part II focuses on the interior structure of the moon, the giant planets and the structure of the Galilean satellites of Jupiter and Titan and the icy satellites of Saturn.
Download or read book Physics Briefs written by and published by . This book was released on 1992 with total page 1332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geomagnetic Field Variations written by K.H. Glaßmeier and published by Springer Science & Business Media. This book was released on 2008-10-20 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth’s magnetic field is currently changing dramatically. Is the observed decrease of the dipole moment indicating a future polarity transition? What would be the effects of such a drastic change on system Earth? Can any positive or negative effects on our biosphere or even humans be expected? This book gives a first overview about the geomagnetic field in general and serves as an introduction into geomagnetism. As the topic of the book covers a wide range of scientific disciplines, the first chapter summarises basic principles of geomagnetism and related fields including a historic overview, instruments and measurements, paleomagnetic fields, basics of dynamo theory, etc. The contributed chapters review major results of international activities aiming at understanding the causes and effects of geomagnetic field variations in view of the questions above.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Magnetohydrodynamics and the Earth s Core written by Andrew M. Soward and published by CRC Press. This book was released on 2002-11-28 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paul Roberts' research contributions are remarkable in their diversity, depth and international appeal. Papers from the Paul Roberts' Anniversary meeting at the University of Exeter are presented in this volume. Topics include geomagnetism and dynamos, fluid mechanics and MHD, superfluidity, mixed phase regions, mean field electrodynamics and the Earth's inner core. An incisive commentary of the papers puts the work of Paul Roberts into historical context. Magnetohydrodynamics and the Earth's Core provides a valuable source of reference for graduates and researchers working in this area of geoscience.
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1982 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
