5,876 research outputs found
MICRO DYNAMICS OF INCOME, DEBT MANAGEMENT AND FARM FINANCIAL PERFORMANCE
Agricultural Finance,
Food Aid as Surplus Disposal? The WTO, Export Competition Disciplines and the Disposition of Food Aid
The empirical investigation suggests that there exists an endogenous relationship between subsidy/credit shipments and food aid for wheat in the US. The empirical VAR demonstrates a contemporaneous increase in food aid shipments as alternative vents constrict. This result suggests that a trade agreement that disciplines export subsidies and credits may put upward pressure on food aid shipments as agricultural exporters vent the pressure of their domestic surpluses. The empirical results suggest that in the US wheat market the effects are not large. The same phenomenon has been noted in the case of skim milk powder by Margulis; skim milk powder would provide another interesting empirical case, were the data available.Food Security and Poverty,
Food Aid as Surplus Disposal? The WTO, Export Competition Disciplines and the Disposition of Food Aid
Food Security and Poverty, International Relations/Trade,
Temperature and Pressure Effects on Hydrogen Permeation in Palladium Based Membranes
Palladium based membranes offer a promising method for extracting hydrogen from multi-component synthetic gas (syngas) mixtures. Thin palladium and palladium alloy membranes supported on porous media combine both enhanced strength and durability with increased permeation. The syngas produced from waste and biomass contains several gases of different concentrations. The availability of clean hydrogen from syngas is novel since the hydrogen storage and transportation are amongst the major issues for the utilization of hydrogen. A lab scale experimental facility has been designed and built that allows one to examine different types of membranes for efficient and effective separation of hydrogen from syngas. Experimental results have been obtained from this facility using palladium membranes. The results show hydrogen permeation increased with both temperature and pressure, with the greatest increase occurring with rising temperature. Determination of the pressure exponent revealed that the reaction was limited by both the surface reaction and diffusion process
RISING FARM DEBT: INCOME AND ASSET VALUE CONSIDERATIONS
Agricultural Finance,
Sky localization of complete inspiral-merger-ringdown signals for nonspinning massive black hole binaries
We investigate the capability of LISA to measure the sky position of
equal-mass, nonspinning black hole binaries, combining for the first time the
entire inspiral-merger-ringdown signal, the effect of the LISA orbits, and the
complete three-channel LISA response. We consider an ensemble of systems near
the peak of LISA's sensitivity band, with total rest mass of 2\times10^6
M\odot, a redshift of z = 1, and randomly chosen orientations and sky
positions. We find median sky localization errors of approximately \sim3
arcminutes. This is comparable to the field of view of powerful electromagnetic
telescopes, such as the James Webb Space Telescope, that could be used to
search for electromagnetic signals associated with merging massive black holes.
We investigate the way in which parameter errors decrease with measurement
time, focusing specifically on the additional information provided during the
merger-ringdown segment of the signal. We find that this information improves
all parameter estimates directly, rather than through diminishing correlations
with any subset of well- determined parameters. Although we have employed the
baseline LISA design for this study, many of our conclusions regarding the
information provided by mergers will be applicable to alternative mission
designs as well.Comment: 9 pages, 5 figures, submitted to Phys. Rev.
Evidence of a Plasmoid-Looptop Interaction and Magnetic Inflows During a Solar Flare/CME Eruptive Event
Observational evidence is presented for the merging of a downward-propagating
plasmoid with a looptop kernel during an occulted limb event on 2007 January
25. RHESSI lightcurves in the 9-18 keV energy range, as well as that of the 245
MHz channel of the Learmonth Solar Observatory, show enhanced nonthermal
emission in the corona at the time of the merging suggesting that additional
particle acceleration took place. This was attributed to a secondary episode of
reconnection in the current sheet that formed between the two merging sources.
RHESSI images were used to establish a mean downward velocity of the plasmoid
of 12 km/s. Complementary observations from the SECCHI suite of instruments
onboard STEREO-Behind showed that this process occurred during the acceleration
phase of the associated CME. From wavelet-enhanced EUVI, images evidence of
inflowing magnetic field lines prior to the CME eruption is also presented. The
derived inflow velocity was found to be 1.5 km/s. This combination of
observations supports a recent numerical simulation of plasmoid formation,
propagation and subsequent particle acceleration due to the tearing mode
instability during current sheet formation.Comment: 8 pages, 9 figures, ApJ (Accepted
Development of a Hard X-Ray Polarimeter for Astrophysics
We have been developing a Compton scatter polarimeter for measuring the linear polarization of hard X-rays (100-300 keV) from astrophysical sources. A laboratory prototype polarimeter has been used to successfully demonstrate the reliability of our Monte Carlo simulation code and to demonstrate our ability to generate a polarized photon source in the lab. Our design concept places a self-containedpolarimeter module on the front-end of a a 5-inch position sensitive PMT (PSPMT). We are currently working on the fabrication of a science model based on this PSPMT concept. Although the emphasis of our development effort is towards measuring hard X-rays from solar flares, our design has the advantage that it is sensitive over a rather large field-of-view (\u3e1 steradian), a feature that makes it especially attractive for γ-ray burst studie
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