4,778 research outputs found
Interaction of Saturn's magnetosphere and its moons: 3. Time variation of the Enceladus plume
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95380/1/jgra20677.pd
Interaction of Saturn's magnetosphere and its moons: 2. Shape of the Enceladus plume
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95207/1/jgra20314.pd
Thermoelectrics Near the Mott Localization-Delocalization Transition
We give an overview on current status of the theoretical research on
Thermoelectricity for correlated materials. We derive the theoretical formulas
which become exact at low and high temperature and discuss the intermediate
temperature results. In particular, we show that within Dynamical Mean Field
Theory the low temperature sign of the thermopower is not necessary the same as
in LDA, and that significant non-universality is expected due to strong
correlations.Comment: appeared in "Properties and Applications of Thermoelectric
Materials", Edited by V. Zlatic and A.C. Hewson, Springe
Selfâconsistent multifluid MHD simulations of Europa's exospheric interaction with Jupiter's magnetosphere
The Jovian moon, Europa, hosts a thin neutral gas atmosphere, which is tightly coupled to Jupiter's magnetosphere. Magnetospheric ions impacting the surface sputter off neutral atoms, which, upon ionization, carry currents that modify the magnetic field around the moon. The magnetic field in the plasma is also affected by Europa's induced magnetic field. In this paper we investigate the environment of Europa using our multifluid MHD model and focus on the effects introduced by both the magnetospheric and the pickup ion populations. The model selfâconsistently derives the electron temperature that governs the electron impact ionization process, which is the major source of ionization in this environment. The resulting magnetic field is compared to measurements performed by the Galileo magnetometer, the bulk properties of the modeled thermal plasma population is compared to the Galileo Plasma Subsystem observations, and the modeled surface precipitation fluxes are compared to Galileo Ultraviolet Spectrometer observations. The model shows good agreement with the measured magnetic field and reproduces the basic features of the plasma interaction observed at the moon for both the E4 and the E26 flybys of the Galileo spacecraft. The simulation also produces perturbations asymmetric about the flow direction that account for observed asymmetries.Key PointsFirst multifluid MHD simulation of Europa's plasma interaction presentedMatches plasma and magnetic field observations during Galileo E4 and E26 flybysPlasma flow and temperatures different for magnetospheric and pick up ionsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111914/1/jgra51773.pd
Interaction of Saturn's magnetosphere and its moons: 1. Interaction between corotating plasma and standard obstacles
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95046/1/jgra20170.pd
Heavy Quasi-Particle in the Two-Orbital Hubbard Model
The two-orbital Hubbard model with the Hund coupling is investigated in a
metallic phase close to the Mott insulator. We calculate the one-particle
spectral function and the optical conductivity within dynamical mean field
theory, for which the effective impurity problem is solved by using the
non-crossing approximation. For a metallic system close to quarter filling, a
heavy quasi-particle band is formed by the Hubbard interaction, the effective
mass of which is not so sensitive to the orbital splitting and the Hund
coupling. In contrast, a heavy quasi-particle band near half filling disappears
in the presence of the orbital splitting, but is induced again by the
introduction of the Hund coupling, resulting in a different type of heavy
quasi-particles.Comment: 6page, 7eps figures, to appear in J. Phys. Soc. Jp
Tuning a Josephson junction through a quantum critical point
We tune the barrier of a Josephson junction through a zero-temperature
metal-insulator transition and study the thermodynamic behavior of the junction
in the proximity of the quantum-critical point. We examine a
short-coherence-length superconductor and a barrier (that is described by a
Falicov-Kimball model) using the local approximation and dynamical mean-field
theory. The inhomogeneous system is self-consistently solved by performing a
Fourier transformation in the planar momentum and exactly inverting the
remaining one-dimensional matrix with the renormalized perturbation expansion.
Our results show a delicate interplay between oscillations on the scale of the
Fermi wavelength and pair-field correlations on the scale of the coherence
length, variations in the current-phase relationship, and dramatic changes in
the characteristic voltage as a function of the barrier thickness or
correlation strength (which can lead to an ``intrinsic'' pinhole effect).Comment: 16 pages, 15 figures, ReVTe
A Rapid Flp-In System for Expression of Secreted H5N1 Influenza Hemagglutinin Vaccine Immunogen in Mammalian Cells
Continuing transmissions of highly pathogenic H5N1 viruses in poultry and humans underscores the need for a rapid response to potential pandemic in the form of vaccine. Recombinant technologies for production of immunogenic hemagglutinin (HA) could provide an advantage over the traditional inactivated vaccine manufacturing process. Generation of stably transfected mammalian cells secreting properly folded HA proteins is important for scalable controlled manufacturing.We have developed a Flp-In based 293 stable cell lines through targeted site-specific recombination for expression of secreted hemagglutinin (HA) proteins and evaluated their immunogenicity. H5N1 globular domain HA1(1-330) and HA0(1-500) proteins were purified from the supernatants of 293 Flp-In stable cell lines. Both proteins were properly folded as confirmed by binding to H5N1-neutralizing conformation-dependent human monoclonal antibodies. The HA0 (with unmodified cleavage site) was monomeric, while the HA1 contained oligomeric forms. Upon rabbit immunization, both HA proteins elicited neutralizing antibodies against the homologous virus (A/Vietnam/1203/2004, clade 1) as well as cross-neutralizing antibodies against heterologous H5N1 clade 2 strains, including A/Indonesia/5/2005. These results exceeded the human antibody responses against the inactivated sub-virion H5N1 vaccine.Our data suggest that the 293 Flp-In system could serve as a platform for rapid expression of HA immunogens in mammalian cells from emerging influenza strains
Tidal Heating: Lessons from Io and the Jovian System (Report from the KISS Workshop)
Summary of the Keck Institute for Space Studies workshop entitled "Tidal Heating: Lessons from Io and the Jovian System," held on October 15-19, 2018
Periodic and Quasiperiodic Motion of an Elongated Microswimmer in Poiseuille Flow
We study the dynamics of a prolate spheroidal microswimmer in Poiseuille flow
for different flow geometries. When moving between two parallel plates or in a
cylindrical microchannel, the swimmer performs either periodic swinging or
periodic tumbling motion. Although the trajectories of spherical and elongated
swimmers are qualitatively similar, the swinging and tumbling frequency
strongly depends on the aspect ratio of the swimmer. In channels with reduced
symmetry the swimmers perform quasiperiodic motion which we demonstrate
explicitely for swimming in a channel with elliptical cross section
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