2,762 research outputs found
Solar Magnetic Tracking. IV. The Death of Magnetic Features
The removal of magnetic flux from the quiet-sun photosphere is important for
maintaining the statistical steady-state of the magnetic field there, for
determining the magnetic flux budget of the Sun, and for estimating the rate of
energy injected into the upper solar atmosphere. Magnetic feature death is a
measurable proxy for the removal of detectable flux. We used the SWAMIS feature
tracking code to understand how nearly 20000 detected magnetic features die in
an hour-long sequence of Hinode/SOT/NFI magnetograms of a region of quiet Sun.
Of the feature deaths that remove visible magnetic flux from the photosphere,
the vast majority do so by a process that merely disperses the
previously-detected flux so that it is too small and too weak to be detected.
The behavior of the ensemble average of these dispersals is not consistent with
a model of simple planar diffusion, suggesting that the dispersal is
constrained by the evolving photospheric velocity field. We introduce the
concept of the partial lifetime of magnetic features, and show that the partial
lifetime due to Cancellation of magnetic flux, 22 h, is 3 times slower than
previous measurements of the flux turnover time. This indicates that prior
feature-based estimates of the flux replacement time may be too short, in
contrast with the tendency for this quantity to decrease as resolution and
instrumentation have improved. This suggests that dispersal of flux to smaller
scales is more important for the replacement of magnetic fields in the quiet
Sun than observed bipolar cancellation. We conclude that processes on spatial
scales smaller than those visible to Hinode dominate the processes of flux
emergence and cancellation, and therefore also the quantity of magnetic flux
that threads the photosphere.Comment: Accepted by Ap
Optical characterization of LDEF contaminant film
Dark brown molecular film deposits were found at numerous locations on the Long Duration Exposure Facility (LDEF) and have been documented in great detail by several investigators. The exact deposition mechanism for these deposits is as yet unknown, although direct and scattered atomic oxygen, and solar radiation interacting with materials outgassing products have all been implicated in the formation process. Specimens of the brown molecular film were taken from below the flange of the experimental tray located at position D10 on the LDEF. The tray was one of two, comprising the same experiment, the other being located on the wake facing side of the LDEF satellite at position B4. Having access to both trays, we were able to directly compare the effect that orientation with respect to the atomic oxygen flux vector had on the formation of the brown molecular film deposits. The film is thickest on surfaces facing toward the exterior, i.e. the tray corner, as can be seen by comparing the lee and wake aspects of the rivets. The patterns appear to be aligned not with the velocity vector but with the corner of the tray suggesting that flux to the surface is due to scattered atomic oxygen rather than direct ram impingement. The role of scattered flux is further supported by more faint plume patterns on the sides of the tray. The angle of these plumes is strongly aligned with the ram direction but the outline of the deposit implies that incident atoms are scattered by collisions with the edges of the opening resulting in a directed, but diffuse, flux of atomic oxygen to the surface. Spectral reflectance measurements in the 2 to 10 micron (4000 to 1000 wavenumbers) spectral range are presented for the film in the 'as deposited' condition and for the free standing film. The material was analyzed by FTIR (Fourier Transform Infrared) microspectroscopy using gold as the reference standard. The 'as deposited' specimen was on an aluminum rivet taken from beneath the tray flange while the free film was obtained by chipping some of the material from the rivet. The transmission spectrum over the 2 to 10 micron range for the free film is presented. This spectrum appears to be essentially the same as that presented by Crutcher et.al. for films formed at vent sites which faced into the ram direction and suggested to originate from urethanes and silicones used on the LDEF. Banks et. al. state that silicones, when exposed to atomic oxygen, release polymeric scission fragments which deposit on surfaces and form a glassy, dark contaminant layer upon further atomic oxygen exposure and solar irradiation
Analysis of a Convective Reaction-Diffusion Equation II
We study the large time behavior of positive solutions of the semilinear parabolic equation , , , subject to . The model problem in which the results apply is and . The steady state problem is analyzed in some detail, and results about finite time blow up are proved
Wealth Building in Rural America: Perspective, Knowledge, Outlook
Wealth Building in Rural America: Perspective, Knowledge, Outloo
Community pharmacy-based medication therapy management services: financial impact for patients
This is the published version. Copyright 2012 Centro de Investigaciones y Publicaciones Farmaceuticas.Objective: To determine the direct financial impact
for patients resulting from Medication Therapy
Management (MTM) interventions made by
community pharmacists. Secondary objectives
include evaluating the patient and physician
acceptance rates of the community pharmacistsâ
recommended MTM interventions.
Methods: This was a retrospective observational
study conducted at 20 Price Chopper and Hen
House grocery store chain pharmacies in the
Kansas City metro area from January 1, 2010 to
December 31, 2010. Study patients were Medicare
Part D beneficiaries eligible for MTM services. The
primary outcome was the change in patient out-ofpocket
prescription medication expense as a result
of MTM services.
Results: Of 128 patients included in this study, 68%
experienced no out-of-pocket financial impact on
their medication expenses as a result of MTM
services. A total of 27% of the patients realized a
cost-savings (USD440.50 per year, (SD=289.69))
while another 5% of patients saw a cost increase in
out-of-pocket expense (USD255.66 per year,
(SD=324.48)). The net financial impact for all 128
patients who participated in MTM services was an
average savings of USD102.83 per patient per year
(SD=269.18, p<0.0001). Pharmacists attempted a
total of 732 recommendations; 391 (53%) were
accepted by both the patient and their prescriber. A
total of 341 (47%) recommendations were not
accepted because of patient refusal (290, 85%) or
prescriber refusal (51, 15%).
Conclusions: Patient participation in MTM services
reduces patient out-of-pocket medication expense.
However, this savings is driven by only 32% of
subjects who are experiencing a financial impact on
out-of-pocket medication expense. Additionally, the
majority of the pharmacistsâ recommended
interventions (53%) were accepted by patients and
prescribers
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