411 research outputs found
TEACHING, RESEARCH, AND EXTENSION PROGRAMS AT PREDOMINANTLY BLACK LAND-GRANT INSTITUTIONS
Teaching/Communication/Extension/Profession,
PART-TIME FARMING: PRODUCTIVITY AND SOME IMPLICATIONS OF OFF-FARM WORK BY FARMERS
Labor and Human Capital,
An investigation of the economic impact of the Ozark Dairy Management Component on low income dairy farmers
"The Ozark Dairy Management Component, initiated April, 1966, had set forth as a major purpose: the improvement of management practices among low income dairy-farmer participants. Accomplishment of the primary and secondary objectives was to have resulted in income levels at least equal to and greater than minimum designated poverty level. Subobjectives as stated in the project proposal, were: 1. To raise income per cow at least $200 over fee costs. 2. To insure enough cows to justify the dairy farmer's time, equipment and investment. 3. To insure enough acreage per cow to furnish a reserve supply of pasture, hay, and other roughage. 4. To assist in securing financing, where needed, whereby the dairy farmer could increase his income by a sufficient amount to pay off borrowed capital, interest, and increase net income. 5.To assist in improving milk quality. 6. To improve and maintain herd health."-Page
Benchmark full configuration-interaction calculations on HF and NH2
Full configuration-interaction (FCI) calculations are performed at selected geometries for the 1-sigma(+) state of HF and the 2-B(1) and 2-A(1) states of NH2 using both DZ and DZP gaussian basis sets. Higher excitations become more important when the bonds are stretched and the self-consistent field (SCF) reference becomes a poorer zeroth-order description of the wave function. The complete active space SCF - multireference configuration-interaction (CASSCF-MRCI) procedure gives excellent agreement with the FCI potentials, especially when corrected with a multi-reference analog of the Davidson correction
The Upper Critical Field in Disordered Two-Dimensional Superconductors
We present calculations of the upper critical field in superconducting films
as a function of increasing disorder (as measured by the normal state
resistance per square). In contradiction to previous work, we find that there
is no anomalous low-temperature positive curvature in the upper critical field
as disorder is increased. We show that the previous prediction of this effect
is due to an unjustified analytical approximation of sums occuring in the
perturbative calculation. Our treatment includes both a careful analysis of
first-order perturbation theory, and a non-perturbative resummation technique.
No anomalous curvature is found in either case. We present our results in
graphical form.Comment: 11 pages, 8 figure
Energy Release During Slow Long Duration Flares Observed by RHESSI
Slow Long Duration Events (SLDEs) are flares characterized by long duration
of rising phase. In many such cases impulsive phase is weak with lack of
typical short-lasting pulses. Instead of that smooth, long-lasting Hard X-ray
(HXR) emission is observed. We analysed hard X-ray emission and morphology of
six selected SLDEs. In our analysis we utilized data from RHESSI and GOES
satellites. Physical parameters of HXR sources were obtained from imaging
spectroscopy and were used for the energy balance analysis. Characteristic time
of heating rate decrease, after reaching its maximum value, is very long, which
explains long rising phase of these flares.Comment: Accepted for publication in Solar Physic
Radio Bursts Associated with Flare and Ejecta in the 13 July 2004 Event
We investigate coronal transients associated with a GOES M6.7 class flare and
a coronal mass ejection (CME) on 13 July 2004. During the rising phase of the
flare, a filament eruption, loop expansion, a Moreton wave, and an ejecta were
observed. An EIT wave was detected later on. The main features in the radio
dynamic spectrum were a frequency-drifting continuum and two type II bursts.
Our analysis shows that if the first type II burst was formed in the low
corona, the burst heights and speed are close to the projected distances and
speed of the Moreton wave (a chromospheric shock wave signature). The
frequency-drifting radio continuum, starting above 1 GHz, was formed almost two
minutes prior to any shock features becoming visible, and a fast-expanding
piston (visible as the continuum) could have launched another shock wave. A
possible scenario is that a flare blast overtook the earlier transient, and
ignited the first type II burst. The second type II burst may have been formed
by the same shock, but only if the shock was propagating at a constant speed.
This interpretation also requires that the shock-producing regions were located
at different parts of the propagating structure, or that the shock was passing
through regions with highly different atmospheric densities. This complex
event, with a multitude of radio features and transients at other wavelengths,
presents evidence for both blast-wave-related and CME-related radio emissions.Comment: 14 pages, 6 figures; Solar Physics Topical Issue, in pres
Coronal Shock Waves, EUV waves, and Their Relation to CMEs. I. Reconciliation of "EIT waves", Type II Radio Bursts, and Leading Edges of CMEs
We show examples of excitation of coronal waves by flare-related abrupt
eruptions of magnetic rope structures. The waves presumably rapidly steepened
into shocks and freely propagated afterwards like decelerating blast waves that
showed up as Moreton waves and EUV waves. We propose a simple quantitative
description for such shock waves to reconcile their observed propagation with
drift rates of metric type II bursts and kinematics of leading edges of coronal
mass ejections (CMEs). Taking account of different plasma density falloffs for
propagation of a wave up and along the solar surface, we demonstrate a close
correspondence between drift rates of type II bursts and speeds of EUV waves,
Moreton waves, and CMEs observed in a few known events.Comment: 30 pages, 15 figures. Solar Physics, published online. The final
publication is available at http://www.springerlink.co
Multiwavelength Observations of Supersonic Plasma Blob Triggered by Reconnection Generated Velocity Pulse in AR10808
Using multi-wavelength observations of Solar and Heliospheric Observatory
(SoHO)/Michelson Doppler Imager (MDI), Transition Region and Coronal Explorer
(TRACE) 171 \AA, and H from Culgoora Solar Observatory at Narrabri,
Australia, we present a unique observational signature of a propagating
supersonic plasma blob before an M6.2 class solar flare in AR10808 on 9th
September 2005. The blob was observed between 05:27 UT to 05:32 UT with almost
a constant shape for the first 2-3 minutes, and thereafter it quickly vanished
in the corona. The observed lower bound speed of the blob is estimated as
215 km s in its dynamical phase. The evidence of the blob with
almost similar shape and velocity concurrent in H and TRACE 171 \AA\
supports its formation by multi-temperature plasma. The energy release by a
recurrent 3-D reconnection process via the separator dome below the magnetic
null point, between the emerging flux and pre-existing field lines in the lower
solar atmosphere, is found to be the driver of a radial velocity pulse outwards
that accelerates this plasma blob in the solar atmosphere. In support of
identification of the possible driver of the observed eruption, we solve the
two-dimensional ideal magnetohydrodynamic equations numerically to simulate the
observed supersonic plasma blob. The numerical modelling closely match the
observed velocity, evolution of multi-temperature plasma, and quick vanishing
of the blob found in the observations. Under typical coronal conditions, such
blobs may also carry an energy flux of 7.0 ergs cm
s to re-balance the coronal losses above active regions.Comment: Solar Physics; 22 Pages; 8 Figure
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