56 research outputs found
Structured ionospheric outflow during the Cassini T55–T59 Titan flybys
No full textDuring the final three of the five consecutive and similar Cassini Titan flybys T55–T59 we observe a region characterized by high plasma densities (electron densities of 1–8 cm3 ) in the tail/nightside of Titan. This region is observed progressively farther downtail from pass to pass and is interpreted as a plume of ionospheric plasma escaping Titan, which appears steady in both location and time. The ions
in this plasma plume are moving in the direction away from Titan and are a mixture of both light and heavy ions with composition revealing that their origin are in Titan’s ionosphere, while the electrons are more isotropically distributed. Magnetic field measurements indicate the presence of a current sheet at the inner edge of this region. We discuss the mechanisms behind this outflow, and suggest that it could be caused by ambipolar diffusion, magnetic moment pumping or dispersive Alfve´n waves.Fil: Edberg, N. J. T.. Swedish Institute of Space Physics; SueciaFil: Ågren, K.. Swedish Institute of Space Physics; SueciaFil: Wahlund, J. E.. Swedish Institute of Space Physics; SueciaFil: Morooka, M. W.. Swedish Institute of Space Physics; SueciaFil: Andrews, D. J.. University of Leicester; Reino UnidoFil: Cowley, S. W. H.. University of Leicester; Reino UnidoFil: Wellbrock, A.. University College London; Estados UnidosFil: Coates, A. J.. University College London; Estados UnidosFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Dougherty, M. K.. Imperial College London; Reino Unid
Aquiloni (book, 2004)
No full textLetterpress (edition of 40), Hahnemuhle and handmade paper, Acrylic paint, thread, w. 5 1/4 x h. 7 3/4 x 43 inches when open, printed and published by Edizioni Pulcinelefante, Osnago, Lecco, Italy, 2004. The text by Roberto Dossi, "Quando sono stanco di camminare, VOLO" ("When I'm tired of walking, I FLY"), was composed specifically for this book and the artist’s installations. Image 2, The book accompanies a large-scale installation of the same name. Installation: handmade paper, Acrylic paint on paper, thread, beeswax and torn prints, size variable, exhibit at Williams Center for the Arts, The Gallery, Lafayette College, Easton, PA, 2006.
(Photograph by Michiko Okaya)6180023,three copies of book , cover and interio
The Art of Marimba in Tokyo: Emergence in the Twentieth Century
No full textThe marimba emerged as a leading voice in contemporary Western art music in the twentieth century. This is due to several key factors: principally the extraordinary contribution composers and performers made to marimba repertoire in Tokyo after 1960. In this paper I will briefly outline the evolution of Western classical music in Japan, from its initial introduction in the latter part of the nineteenth century, to the proliferation of performing arts organizations in the late twentieth century. I will also explore the origins of the xylophone and marimba in Japan and the rise of the marimba through virtuoso performers, competitive instrument manufacturers and (most importantly) leading composers including commissioning practices, funding models and repertoire development. Information to support this paper was gathered in November, 2014 through personal interviews conducted by the author with performers and composers in Tokyo, Japan. These participants include marimbists Keiko Abe, Mutsuko Fujii, Michiko Takahashi, Sumire Yoshihara and composers Norio Fukushi, Jo Kondo, Toshi Ichiyanagi, Tokuhide Niimi, Yasuo Sueyoshi and Katsuhiro Tsubonoh; all of whom were some of the most active contributors to the development of the marimba in Japan in the late twentieth century and whose work is internationally celebrated. Most importantly, connections are identified between these performers, composers, instrument manufacturers, presenting organizations and funding systems that nurtured an environment for these marimba works to be created.D.M.A
An estimate of the dust pickup current at Enceladus
No full textWe demonstrate that the acceleration of submicron dust originating at Enceladus by a reduced co-rotating E-field is capable of creating a dust pickup current perpendicular to the magnetic field with values ranging from 3 to 15 kA (depending upon the effective grain charge). Such a current represents a new contribution to the total pickup current in the region. As such, we suggest that dust pickup currents, along with ion and electron pickup currents, are all active within the plume
Characteristics of the dust–plasma interaction near Enceladus’ South Pole
No full textWe present RPWS Langmuir probe data from the third Enceladus flyby (E3) showing the presence of dusty plasma near Enceladus' South Pole. There is a sharp rise in both the electron and ion number densities when the spacecraft traverses through Enceladus plume. The ion density near Enceladus is found to increase abruptly from about 10(2) cm(-3) before the closest approach to 10(5) cm(-3) just 30 s after the closest approach, an amount two orders of magnitude higher than the electron density. Assuming that the inconsistency between the electron and ion number densities is due to the presence of dust particles that are collecting the missing electron charges, we present dusty plasma characteristics down to sub-micron particle sizes. By assuming a differential dust number density for a range in dust sizes and by making use of Langmuir probe data, the dust densities for certain lower limits in dust size distribution were estimated. In order to achieve the dust densities of micrometer and larger sized grains comparable to the ones reported in the literature, we show that the power law size distribution must hold down to at least 0.03 mu m such that the total differential number density is dominated by the smallest sub-micron sized grains. The total dust number density in Enceladus' plume is of the order of 10(2) cm(-3) reducing to 1 cm(-3) in the E-ring. The dust density for micrometer and larger sized grains is estimated to be about 10(-4) cm(-3) in the plume while it is about 10(-6)-10(-7) cm(-3) in the E-ring. Dust charge for micron sized grains is estimated to be about eight thousand electron charges reducing to below one hundred electron charges for 0.03 mu m sized grains. The effective dusty plasma Debye length is estimated and compared with intergrain distance as well as the electron Debye length. The maximum dust charging time of 1.4 h is found for 0.03 mu m sized grains just 1 min before the closest approach. The charging time decreases substantially in the plume where it is only a fraction of a second for 1 mu m sized grains, 1 s for 0.1 mu m sized grains and about 10 s for 0.03 mu m sized grains.</p
Ion trapping by dust grains : Simulation applications to the Enceladus plume
No full textUsing a particle-in-cell electrostatic simulation, we examine the conditions that allow low-energy ions, like those produced in the Enceladus plume, to be attracted and trapped within the sheaths of negatively charged dust grains. The conventional wisdom is that all new ions produced in the Enceladus plume are free to get picked up (i.e., accelerated by the local E field to then undergo vB acceleration). However, we suggest herein that the presence of submicron-charged dust in the plume impedes this pickup process since the local grain electric field greatly exceeds the corotation E fields. The simulations demonstrate that cold ions will tend to accelerate toward the negatively charged grains and become part of the ion plasma sheath. These trapped ions will move with the grains, exiting the plume region at the dust speed. We suggest that Cassini's Langmuir probe is measuring the entire ion population (free and trapped ions), while the Cassini magnetometer detects the magnetic perturbations associated with pickup currents from the smaller population of free ions, with this distinction possibly reconciling the ongoing debate in the literature on the ion density in the plume
The financial crisis of 2008 in fixed income markets
No full textWe explore how a relatively small amount of heterogeneous securities created turmoil in financial markets in much of the world in 2007 and 2008. The drivers of the financial turmoil and the financial crisis of 2008 were heterogeneous securities that were hard to value. These securities created concerns about counterparty risk and ultimately created substantial uncertainty. The problems spread in ways that were hard to see in advance. The run on prime money market funds in September 2008 and the effects on commercial paper were an important aspect of the crisis itself and are discussed in some detail.
The inner magnetosphere of Saturn : Cassini RPWS cold plasma results from the first encounter
No full textMR-SDCI + Q AB INITIO MOLECULAR ORBITAL CALCULATIONS OF FeCO: IMPORTANCE OF WELL-CONTRIVED SA-MCSCF WAVE FUNCTIONS AND ELECTRON CORRELATIONS
No full textA. Ricca and C. W. Bauschlicher, Theor Chem. Acc. 106, 314, (2001). T. Noro, M. Sekiya, T. Koga, and H. Matsuyama, Theor Chem. Acc. 104, 146, (2000). P. W. Villalta and D. G. Leopold, J. Chem. Phys. 98, 7730, (1993). K. Tanaka, S. Sakaguchi, and T. Tanaka, J. Chem. Phys. 106, 2118, (1997).Author Institution: Department of Chemistry, Faculty of Science, Ochanomizu University; Tsukuba Advanced Computing Center, National Institute of Advanced Industrial Science and Technology; Division of Chemistry, Graduate School of Science, Hokkaido UniversityFeCO has been used as a benchmark molecule to evaluate the basis functions for and the methods of calculation since it is known to be difficult to reproduce the energy difference between the and the states as well as the experimentally observed bond lengths of the state by ab initio molecular orbital calculations. We carried out the MR-SDCI + Q and MR-ACPF calculations, based on the state-averaged MCSCF orbitals, taking into account the electron-correlation of electrons with the active space consisting of Fe 3d, 4s orbitals and orbitals. Our predicted term value of the state, bond lengths and of the state are 0.87 kcal , and with relativistic energy corrections, which are to be compared with the corresponding experimental values of 3.24 kcal and respectively. Similar results have also been obtained by the MR-ACPF methods
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