131 research outputs found
Social and Behavioral Domains in Acute Care Electronic Health Records: Barriers, Facilitators, Relevance, and Value.
Ph.D. Thesis. University of Hawaiʻi at Mānoa 2018
Porous Superhydrophobic Membranes: Hydrodynamic Anomaly in Oscillating Flows
We have fabricated and characterized a novel superhydrophobic system, a
mesh-like porous superhydrophobic membrane with solid area fraction ,
which can maintain intimate contact with outside air and water reservoirs
simultaneously. Oscillatory hydrodynamic measurements on porous
superhydrophobic membranes as a function of reveal surprising effects.
The hydrodynamic mass oscillating in-phase with the membranes stays constant
for , but drops precipitously for . The viscous
friction shows a similar drop after a slow initial decrease proportional to
. We attribute these effects to the percolation of a stable Knudsen
layer of air at the interface.Comment: 5 pages, 3 figure
Gerasimov-Drell-Hearn Sum Rule and the Discrepancy between the New CLAS and SAPHIR Data
Contribution of the K^+\Lambda channel to the Gerasimov-Drell-Hearn (GDH) sum
rule has been calculated by using the models that fit the recent SAPHIR or CLAS
differential cross section data. It is shown that the two data sets yield quite
different contributions. Contribution of this channel to the forward spin
polarizability of the proton has been also calculated. It is also shown that
the inclusion of the recent CLAS C_x and C_z data in the fitting data base does
not significantly change the result of the present calculation. Results of the
fit, however, reveal the role of the S_{11}(1650), P_{11}(1710), P_{13}(1720),
and P_{13}(1900) resonances for the description of the C_x and C_z data. A
brief discussion on the importance of these resonances is given. Measurements
of the polarized total cross section \sigma_{TT'} by the CLAS, LEPS, and MAMI
collaborations are expected to verify this finding.Comment: 15 pages, 8 figure
Coherent Control of Atomic Beam Diffraction by Standing Light
Quantum interference is shown to deliver a means of regulating the
diffraction pattern of a thermal atomic beam interacting with two standing wave
electric fields. Parameters have been identified to enhance the diffraction
probability of one momentum component over the others, with specific
application to Rb atoms.Comment: 5 figure
Scaling laws in velocity-selective coherent population trapping in the presence of polarization-gradient cooling
One-dimensional laser cooling based on velocity-selective coherent population trapping (VSCPT) on a 2g→1e transition has been investigated numerically through the solution of the optical Bloch equations. As in the work of G. Morigi et al. [Phys. Rev. A 53, 2616 (1996)], it has been found that for a large set of atomic and laser parameters, the VSCPT cooling process may be described through scaling-law relations. The scaling laws are based on the relations between the loss rates at large atomic momentum and their dependence on the momentum around zero value. The role of the laser detuning on the VSCPT trapping efficiency has been examined and scaling laws including the detuning have been derived
Atom-optics hologram in the time domain
The temporal evolution of an atomic wave packet interacting with object and
reference electromagnetic waves is investigated beyond the weak perturbation of
the initial state. It is shown that the diffraction of an ultracold atomic beam
by the inhomogeneous laser field can be interpreted as if the beam passes
through a three-dimensional hologram, whose thickness is proportional to the
interaction time. It is found that the diffraction efficiency of such a
hologram may reach 100% and is determined by the duration of laser pulses. On
this basis a method for reconstruction of the object image with matter waves is
offered.Comment: RevTeX, 13 pages, 8 figures; minor grammatical change
Quantum-state control in optical lattices
We study the means to prepare and coherently manipulate atomic wave packets
in optical lattices, with particular emphasis on alkali atoms in the
far-detuned limit. We derive a general, basis independent expression for the
lattice operator, and show that its off-diagonal elements can be tailored to
couple the vibrational manifolds of separate magnetic sublevels. Using these
couplings one can evolve the state of a trapped atom in a quantum coherent
fashion, and prepare pure quantum states by resolved-sideband Raman cooling. We
explore the use of atoms bound in optical lattices to study quantum tunneling
and the generation of macroscopic superposition states in a double-well
potential. Far-off-resonance optical potentials lend themselves particularly
well to reservoir engineering via well controlled fluctuations in the
potential, making the atom/lattice system attractive for the study of
decoherence and the connection between classical and quantum physics.Comment: 35 pages including 8 figures. To appear in Phys. Rev. A. March 199
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