6,510 research outputs found
State Cooperative Councils: What are the Local Member Cooperatives Looking For?
State cooperative councils serve a valuable role for local cooperatives by providing services including education, legislative monitoring and lobbying, and promotion of the cooperative form of business. This paper outlines the specific challenges that state councils are experiencing in today's changing agribusiness environment. The results of a survey of members of the Colorado Cooperative Council are reported. Logit analysis is performed to identify the factors contributing to the cooperatives' satisfaction with the state council and the cooperatives' use of the council's services. The paper concludes with suggestions for action by state councils.Agribusiness,
Energy levels and radiative rates for transitions in Fe V, Co VI and Ni VII
Energy levels, Land\'{e} -factors and radiative lifetimes are reported for
the lowest 182 levels of the 3d, 3d4s and 3d4p configurations of
Fe~V, Co~VI and Ni~VII. Additionally, radiative rates (-values) have been
calculated for the E1, E2 and M1 transitions among these levels. The
calculations have been performed in a quasi-relativistic approach (QR) with a
very large {\em configuration interaction} (CI) wavefunction expansion, which
has been found to be necessary for these ions. Our calculated energies for all
ions are in excellent agreement with the available measurements, for most
levels. Discrepancies among various calculations for the radiative rates of E1
transitions in Fe~V are up to a factor of two for stronger transitions (), and larger (over an order of magnitude) for weaker ones. The reasons for
these discrepancies have been discussed and mainly are due to the differing
amount of CI and methodologies adopted. However, there are no appreciable
discrepancies in similar data for M1 and E2 transitions, or the -factors for
the levels of Fe~V, the only ion for which comparisons are feasible.Comment: This paper of 78 pages including 9 Tables will appear in ADNDT (2016
Plasma properties and Stokes profiles during the lifetime of a photospheric magnetic bright point
Aims: to investigate the evolution of plasma properties and Stokes parameters
in photospheric magnetic bright points using 3D magneto-hydrodynamical
simulations and radiative diagnostics of solar granulation. Methods: simulated
time-dependent radiation parameters and plasma properties were investigated
throughout the evolution of a bright point. Synthetic Stokes profiles for the
FeI 630.25 nm line were calculated, which allowed the evolution of the Stokes-I
line strength and Stokes-V area and amplitude asymmetries to also be
investigated. Results: our results are consistent with theoretical predictions
and published observations describing convective collapse, and confirm this as
the bright point formation process. Through degradation of the simulated data
to match the spatial resolution of SOT, we show that high spatial resolution is
crucial for the detection of changing spectro-polarimetric signatures
throughout a magnetic bright point's lifetime. We also show that the signature
downflow associated with the convective collapse process is reduced towards
zero as the radiation intensity in the bright point peaks, due to the magnetic
forces present restricting the flow of material in the flux tube.Comment: 14 pages, 12 figures, accepted to A&
An assessment of Fe XX - Fe XXII emission lines in SDO/EVE data as diagnostics for high density solar flare plasmas using EUVE stellar observations
The Extreme Ultraviolet Variability Experiment (EVE) on the Solar Dynamics
Observatory obtains extreme-ultraviolet (EUV) spectra of the full-disk Sun at a
spectral resolution of ~1 A and cadence of 10 s. Such a spectral resolution
would normally be considered to be too low for the reliable determination of
electron density (N_e) sensitive emission line intensity ratios, due to
blending. However, previous work has shown that a limited number of Fe XXI
features in the 90-60 A wavelength region of EVE do provide useful
N_e-diagnostics at relatively low flare densities (N_e ~ 10^11-10^12 cm^-3).
Here we investigate if additional highly ionised Fe line ratios in the EVE
90-160 A range may be reliably employed as N_e-diagnostics. In particular, the
potential for such diagnostics to provide density estimates for high N_e
(~10^13 cm^-3) flare plasmas is assessed. Our study employs EVE spectra for
X-class flares, combined with observations of highly active late-type stars
from the Extreme Ultraviolet Explorer (EUVE) satellite plus experimental data
for well-diagnosed tokamak plasmas, both of which are similar in wavelength
coverage and spectral resolution to those from EVE. Several ratios are
identified in EVE data which yield consistent values of electron density,
including Fe XX 113.35/121.85 and Fe XXII 114.41/135.79, with confidence in
their reliability as N_e-diagnostics provided by the EUVE and tokamak results.
These ratios also allow the determination of density in solar flare plasmas up
to values of ~10^13 cm^-3.Comment: 7 pages, 3 figures, 2 tables, MNRAS in pres
Apollo 9 multiband photography experiment 5065 Interim post-flight calibration report
Camera and filter postflight spectrum analysis for Apollo 9 multiband photography experimen
Energy levels and radiative rates for transitions in Cr-like Co IV and Ni V
We report calculations of energy levels and radiative rates (-values) for
transitions in Cr-like Co IV and Ni V. The quasi-relativistic Hartree-Fock
(QRHF) code is adopted for calculating the data although GRASP (general-purpose
relativistic atomic structure package) and flexible atomic code (FAC) have also
been employed for comparison purposes. No radiative rates are available in the
literature to compare with our results, but our calculated energies are in
close agreement with those compiled by NIST for a majority of the levels.
However, there are discrepancies for a few levels of up to 3\%. The -values
are listed for all significantly contributing E1, E2 and M1 transitions, and
the corresponding lifetimes reported, although unfortunately no previous
theoretical or experimental results exist to compare with our data.Comment: The paper will appear in ADNDT (2016) and in October 2015 on the we
Two-stage fan. 3: Data and performance with rotor tip casing treatment, uniform and distorted inlet flows
A two stage fan with a 1st-stage rotor design tip speed of 1450 ft/sec, a design pressure ratio of 2.8, and corrected flow of 184.2 lbm/sec was tested with axial skewed slots in the casings over the tips of both rotors. The variable stagger stators were set in the nominal positions. Casing treatment improved stall margin by nine percentage points at 70 percent speed but decreased stall margin, efficiency, and flow by small amounts at design speed. Treatment improved first stage performance at low speed only and decreased second stage performance at all operating conditions. Casing treatment did not affect the stall line with tip radially distorted flow but improved stall margin with circumferentially distorted flow. Casing treatment increased the attenuation for both types of inlet flow distortion
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