2,603 research outputs found
Bibliography on heavy vehicle dynamics
http://deepblue.lib.umich.edu/bitstream/2027.42/108243/1/103019.pdfDescription of 103019.pdf : Bibliograph
Zebrafish atoh1 genes: classic proneural activity in the inner ear and regulation by Fgf and Notch
Collisionless Magnetic Reconnection via Alfven Eigenmodes
We propose an analytic approach to the problem of collisionless magnetic
reconnection formulated as a process of Alfven eigenmodes' generation and
dissipation. Alfven eigenmodes are confined by the current sheet in the same
way that quantum mechanical waves are confined by the tanh^2 potential. The
dynamical time scale of reconnection is the system scale divided by the
eigenvalue propagation velocity of the n=1 mode. The prediction of the n=1 mode
shows good agreement with the in situ measurement of the
reconnection-associated Hall fields
Steady Hall Magnetohydrodynamics Near a X-type Magnetic Neutral Line
Hall magnetohydrodynamics (MHD) properties near a two-dimensional (2D) X-type
magnetic neutral line in the steady state are considered via heuristic and
rigorous developments. Upon considering the steady-state as the asymptotic
limit of the corresponding \textit{time-dependent} problem and using a rigorous
development, Hall effects are shown to be able to sustain the hyperbolicity of
the magnetic field (and hence a more open X-point configuration) near the
neutral line in the steady state. The heuristic development misses this subtle
connection of the steady state with the corresponding \textit{time-dependent}
problem and predicts only an elongated current-sheet configuration (as in
resistive MHD). However, the heuristic development turns out to be useful in
providing insight into the lack of dependence of the reconnection rate on the
mechanism breaking the frozen-in condition of the magnetic field lines. The
latter result can be understood in terms of the ability of the ions and
electrons to transport equal amounts of magnetic flux per unit time out of the
reconnection region.Comment: 1-10 page
Editorial: Advances and Challenges of RNAi Based Technologies for Plants—Volume 2
Editorial on the Research Topic: Advances and Challenges of RNAi Based Technologies for Plants—Volume
The relevance of ERTS-1 data to the state of Ohio
There are no author-identified significant results in this report
X-point collapse and saturation in the nonlinear tearing mode reconnection
We study the nonlinear evolution of the resistive tearing mode in slab
geometry in two dimensions. We show that, in the strongly driven regime (large
Delta'), a collapse of the X-point occurs once the island width exceeds a
certain critical value ~1/Delta'. A current sheet is formed and the
reconnection is exponential in time with a growth rate ~eta^1/2, where eta is
the resistivity. If the aspect ratio of the current sheet is sufficiently
large, the sheet can itself become tearing-mode unstable, giving rise to
secondary islands, which then coalesce with the original island. The saturated
state depends on the value of Delta'. For small Delta', the saturation
amplitude is ~Delta' and quantitatively agrees with the theoretical prediction.
If Delta' is large enough for the X-point collapse to have occured, the
saturation amplitude increases noticeably and becomes independent of Delta'.Comment: revtex4, 4 pages, 18 figure
Evidence for a singularity in ideal magnetohydrodynamics: implications for fast reconnection
Numerical evidence for a finite-time singularity in ideal 3D
magnetohydrodynamics (MHD) is presented. The simulations start from two
interlocking magnetic flux rings with no initial velocity. The magnetic
curvature force causes the flux rings to shrink until they come into contact.
This produces a current sheet between them. In the ideal compressible
calculations, the evidence for a singularity in a finite time is that the
peak current density behaves like for a range of
sound speeds (or plasma betas). For the incompressible calculations consistency
with the compressible calculations is noted and evidence is presented that
there is convergence to a self-similar state. In the resistive reconnection
calculations the magnetic helicity is nearly conserved and energy is
dissipated.Comment: 4 pages, 4 figure
1935: Abilene Christian College Bible Lectures - Full Text
Delivered in the auditorium of Abilene Christian College, Abilene, Texas, February 193
The Economic Resource Receipt of New Mothers
U.S. federal policies do not provide a universal social safety net of economic support for women during pregnancy or the immediate postpartum period but assume that employment and/or marriage will protect families from poverty. Yet even mothers with considerable human and marital capital may experience disruptions in employment, earnings, and family socioeconomic status postbirth. We use the National Survey of Families and Households to examine the economic resources that mothers with children ages 2 and younger receive postbirth, including employment, spouses, extended family and social network support, and public assistance. Results show that many new mothers receive resources postbirth. Marriage or postbirth employment does not protect new mothers and their families from poverty, but education, race, and the receipt of economic supports from social networks do
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