559 research outputs found
Study of rock experiments to measure interplanetary energetic hydrogen fluxes and hydrogen fluxes during an auroral breakup
Flux, energy spectra, and pitch angle distributions of precipitated low energy hydrogen and electrons from Nike-Tomahawk auroral hydrogen experimen
Auroral rocket experiment 2 Final report
Detecting fluxes of energetic neutral hydrogen atoms in interplanetary medium by auroral rocket flight
Study of an auroral zone rocket experiment Final report
Measurement of flux and energy spectra of protons, energetic particles, hydrogen atoms, and electrons in auroral zone by Nike-Tomahawk sounding rocke
Research Notes: U.S. Regional Soybean Laboratory and University of Illinois, Urbana-Champaign
Chief\u27, a very tall Maturity Group IV variety, was used as a donor parent in backcrossing to \u27Clark\u27 to transfer Np (a gene for high phosphorus tolerance). In the field in 1963, I grew progenies from 40 selected Np F2 plants from Clark BC5 and was surprised to see 2 of the progenies uniformly very tall and 3 of them segregating approximately 1/4 tall plants. The Np gene appears to have no effect on field-grown plants in normal soils
Intraoperative Management of Robotic-Assisted Versus Open Radical Prostatectomy
Robotic-assisted laparoscopic radical prostatectomy was found to be a shorter procedure characterized by minimal blood loss, reduced fluid requirements, and shorter hospital stay compared with traditional open procedures
Measured quantum probability distribution functions for Brownian motion
The quantum analog of the joint probability distributions describing a
classical stochastic process is introduced. A prescription is given for
constructing the quantum distribution associated with a sequence of
measurements. For the case of quantum Brownian motion this prescription is
illustrated with a number of explicit examples. In particular it is shown how
the prescription can be extended in the form of a general formula for the
Wigner function of a Brownian particle entangled with a heat bath.Comment: Phys. Rev. A, in pres
Theory of Adiabatic fluctuations : third-order noise
We consider the response of a dynamical system driven by external adiabatic
fluctuations. Based on the `adiabatic following approximation' we have made a
systematic separation of time-scales to carry out an expansion in , where is the strength of fluctuations and is the
damping rate. We show that probability distribution functions obey the
differential equations of motion which contain third order terms (beyond the
usual Fokker-Planck terms) leading to non-Gaussian noise. The problem of
adiabatic fluctuations in velocity space which is the counterpart of Brownian
motion for fast fluctuations, has been solved exactly. The characteristic
function and the associated probability distribution function are shown to be
of stable form. The linear dissipation leads to a steady state which is stable
and the variances and higher moments are shown to be finite.Comment: Plain Latex, no figures, 28 pages; to appear in J. Phys.
Brownian Simulations and Uni-Directional Flux in Diffusion
Brownian dynamics simulations require the connection of a small discrete
simulation volume to large baths that are maintained at fixed concentrations
and voltages. The continuum baths are connected to the simulation through
interfaces, located in the baths sufficiently far from the channel. Average
boundary concentrations have to be maintained at their values in the baths by
injecting and removing particles at the interfaces. The particles injected into
the simulation volume represent a unidirectional diffusion flux, while the
outgoing particles represent the unidirectional flux in the opposite direction.
The classical diffusion equation defines net diffusion flux, but not
unidirectional fluxes. The stochastic formulation of classical diffusion in
terms of the Wiener process leads to a Wiener path integral, which can split
the net flux into unidirectional fluxes. These unidirectional fluxes are
infinite, though the net flux is finite and agrees with classical theory. We
find that the infinite unidirectional flux is an artifact caused by replacing
the Langevin dynamics with its Smoluchowski approximation, which is classical
diffusion. The Smoluchowski approximation fails on time scales shorter than the
relaxation time of the Langevin equation. We find the unidirectional
flux (source strength) needed to maintain average boundary concentrations in a
manner consistent with the physics of Brownian particles. This unidirectional
flux is proportional to the concentration and inversely proportional to
to leading order. We develop a BD simulation that maintains
fixed average boundary concentrations in a manner consistent with the actual
physics of the interface and without creating spurious boundary layers
Random paths and current fluctuations in nonequilibrium statistical mechanics
An overview is given of recent advances in nonequilibrium statistical
mechanics about the statistics of random paths and current fluctuations.
Although statistics is carried out in space for equilibrium statistical
mechanics, statistics is considered in time or spacetime for nonequilibrium
systems. In this approach, relationships have been established between
nonequilibrium properties such as the transport coefficients, the thermodynamic
entropy production, or the affinities, and quantities characterizing the
microscopic Hamiltonian dynamics and the chaos or fluctuations it may generate.
This overview presents results for classical systems in the escape-rate
formalism, stochastic processes, and open quantum systems
The influence of charge detection on counting statistics
We consider the counting statistics of electron transport through a double
quantum dot with special emphasis on the dephasing induced by a nearby charge
detector. The double dot is embedded in a dissipative enviroment, and the
presence of electrons on the double dot is detected with a nearby quantum point
contact. Charge transport through the double dot is governed by a non-Markovian
generalized master equation. We describe how the cumulants of the current can
be obtained for such problems, and investigate the difference between the
dephasing mechanisms induced by the quantum point contact and the coupling to
the external heat bath. Finally, we consider various open questions of
relevance to future research.Comment: 15 pages, 2 figures, Contribution to 5-th International Conference on
Unsolved Problems on Noise, Lyon, France, June 2-6, 200
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