The response of local governments to Reagan-Bush fiscal federalism

Fiscal policy ; Local government

The role of energy productivity in the U.S. agriculture

This paper investigates the role of energy on U.S. agricultural productivity using panel data at the state level for the period 1960-2004. We first provide a historical account of energy use in U.S. agriculture. To do this we rely on the Bennet cost indicator to study how the price and volume components of energy costs have developed over time. We then proceed to analyze the contribution of energy to productivity in U.S. agriculture employing the Bennet-Bowley productivity indicator. An important feature of the Bennet-Bowley indicator is its direct association with the change in (normalized) profits. Thus our study is also able to analyze the link between profitability and productivity in U.S. agriculture. Panel regression estimates indicate that energy prices have a negative effect on profitability in the U.S. agricultural sector. We also find that energy productivity has generally remained below total farm productivity following the 1973-1974 global energy crisis

Thomson scattering from a shock front

We have obtained a Thomson scattering spectrum in the collective regime by scattering a probe beam from a shock front, in an experiment conducted at the Omega laser at the Laboratory for Laser Energetics. The probe beam was created by frequency converting a beamline at Omega to a 2 ns2ns pulse of 0.263 μm0.263μm light, focused with a dedicated optical focusing system. The diagnostic system included collecting optics, spectrometer, and streak camera, with a scattering angle of 101°. The target included a primary shock tube, a 20-μm20-μm-thick beryllium drive disk, 0.3-μm0.3-μm-thick polyimide windows mounted on a secondary tube, and a gas fill tube. Detected acoustic waves propagated parallel to the target axis. Ten laser beams irradiated the beryllium disk with 0.351 μm0.351μm light at 5×1014 W/cm25×1014W∕cm2 for 1 ns1ns starting at toto, driving a strong shock through argon gas at ρo = 1 mg/ccρo=1mg∕cc. The 200 J200J probe beam fired at t = 19 nst=19ns for 2 ns2ns, and at t = 20.1 nst=20.1ns a 0.3 ns0.3ns signal was detected. We attribute this signal to scattering from the shocked argon, before the density increased above critical due to radiative collapse.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87893/2/10E504_1.pd

The role of energy productivity in US agriculture

This paper investigates the role of energy on U.S. agricultural productivity using panel data at the state level for the period 1960–2004.We first provide a historical account of energy use in U.S. agriculture. To do this we rely on the Bennet cost indicator to study how the price and volume components of energy costs have developed over time. We then proceed to analyze the contribution of energy to productivity in U.S. agriculture employing the Bennet–Bowley productivity indicator. An important feature of the Bennet–Bowley indicator is its direct association with the change in (normalized) profits. Thus our study is also able to analyze the link between profitability and productivity. Panel regression estimates indicate that energy prices have a negative effect on profitability in the U.S. agricultural sector. We also find that energy productivity has generally remained below total farm productivity following the 1973–1974 global energy crisis.Keywords: Agricultural productivity, Bennet-Bowley indicator, Energy productivit

Dual, orthogonal, backlit pinhole radiography in OMEGA experiments

Backlit pinhole radiography used with ungated film as a detector creates x-ray radiographs with increased resolution and contrast. Current hydrodynamics experiments on the OMEGA Laser use a three-dimensional sinusoidal pattern as a seed perturbation for the study of instabilities. The structure of this perturbation makes it highly desirable to obtain two simultaneous orthogonal backlighting views. We accomplished this using two backlit pinholes each mounted 12 mm12mm from the target. The pinholes, of varying size and shape, were centered on 5 mm5mm square foils of 50 μm50μm thick Ta. The backlighting is by KK-alpha emission from a 500 μm500μm square Ti or Sc foil mounted 500 μm500μm from the Ta on a plastic substrate. Four laser beams overfill the metal foil, so that the expanding plastic provides radial tamping of the expanding metal plasma. The resulting x-rays pass through the target onto (ungated) direct exposure film (DEF). Interference between the two views is reduced by using a nose cone in front of the DEF, typically with a 9 mm9mm Ta aperture and with magnets to deflect electrons. Comparison of varying types of pinholes and film exposures will be presented from recent experiments as well as an analysis of the background noise created using this experimental technique.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87894/2/10E327_1.pd

Observation of collapsing radiative shocks in laboratory experiments

This article reports the observation of the dense, collapsed layer produced by a radiative shock in a laboratory experiment. The experiment uses laser irradiation to accelerate a thin layer of solid-density material to above 100 km/s100km∕s, the first to probe such high velocities in a radiative shock. The layer in turn drives a shock wave through a cylindrical volume of Xe gas (at ∼ 6 mg/cm3∼6mg∕cm3). Radiation from the shocked Xe removes enough energy that the shocked layer increases in density and collapses spatially. This type of system is relevant to a number of astrophysical contexts, providing the potential to observe phenomena of interest to astrophysics and to test astrophysical computer codes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87760/2/082901_1.pd

Western Pacific atmospheric nutrient deposition fluxes, their impact on surface ocean productivity

The atmospheric deposition of both macronutrients and micronutrients plays an important role in driving primary productivity, particularly in the low-latitude ocean. We report aerosol major ion measurements for five ship-based sampling campaigns in the western Pacific from similar to 25 degrees N to 20 degrees S and compare the results with those from Atlantic meridional transects (similar to 50 degrees N to 50 degrees S) with aerosols collected and analyzed in the same laboratory, allowing full incomparability. We discuss sources of the main nutrient species (nitrogen (N), phosphorus (P), and iron (Fe)) in the aerosols and their stoichiometry. Striking north-south gradients are evident over both basins with the Northern Hemisphere more impacted by terrestrial dust sources and anthropogenic emissions and the North Atlantic apparently more impacted than the North Pacific. We estimate the atmospheric supply rates of these nutrients and the potential impact of the atmospheric deposition on the tropical western Pacific. Our results suggest that the atmospheric deposition is P deficient relative to the needs of the resident phytoplankton. These findings suggest that atmospheric supply of N, Fe, and P increases primary productivity utilizing some of the residual excess phosphorus (P*) in the surface waters to compensate for aerosol P deficiency. Regional primary productivity is further enhanced via the stimulation of nitrogen fixation fuelled by the residual atmospheric iron and P*. Our stoichiometric calculations reveal that a P* of 0.1 mu mol L-1 can offset the P deficiency in atmospheric supply for many months. This study suggests that atmospheric deposition may sustain similar to 10% of primary production in both the western tropical Pacific

TWO-DIMENSIONAL BLAST-WAVE-DRIVEN RAYLEIGH-TAYLOR INSTABILITY: EXPERIMENT AND SIMULATION

This paper shows results from experiments diagnosing the development of the Rayleigh–Taylor instability with two-dimensional initial conditions at an embedded, decelerating interface. Experiments are performed at the Omega Laser and use ~5 kJ of energy to create a planar blast wave in a dense, plastic layer that is followed by a lower density foam layer. The single-mode interface has a wavelength of 50 μm and amplitude of 2.5 μm. Some targets are supplemented with additional modes. The interface is shocked then decelerated by the foam layer. This initially produces the Richtmyer–Meshkov instability followed and then dominated by Rayleigh–Taylor growth that quickly evolves into the nonlinear regime. The experimental conditions are scaled to be hydrodynamically similar to SN1987A in order to study the instabilities that are believed to occur at the He/H interface during the blast-wave-driven explosion phase of the star. Simulations of the experiment were performed using the FLASH hydrodynamics code.United States. Dept. of Energy (Stewardship Science Academic Alliances Program. Grant DE FG03-99DP00284)United States. Dept. of Energy (Stewardship Science Academic Alliances Program. Grant DE-FG03-00SF22021