Experiments in Aggregating Air Ordnance Effectiveness Data for the TACWAR Model

An interactive MS Access&trademark; based application that aggregates the output of the SABSEL model for input into the TACWAR model is developed. The application was developed following efforts to create a functional approximation of the SABSEL data using neural networks, statistical networks, and traditional statistical techniques. These approximations were compared to a look-up table methodology on the basis of accuracy, (RMS

Interwar Price Level Targeting

Fackler and Parker argue that the Great Depression may have been preventable with a formalized policy rule proposed by economist Irving Fisher. Policymakers have an ongoing debate about whether formalized policy rules are better than discretionary policy decisions for economic outcomes. The authors’ analysis suggests that in the case of the Great Depression, if Fisher’s policy rule had been adopted in 1930 the collapse of the economy would have been avoided

ECONOMIC, ENVIRONMENTAL AND ENERGY USE IMPLICATIONS OF SHORT-SEASON COTTON PRODUCTION: TEXAS LOWER RIO GRANDE VALLEY

Crop Production/Industries,

An Electrically Detonated Downhole Seismic Gun

An electrically detonated downhole seismic gun (EDG) that will fire blank 8-guage shells underwater has been constructed and tested to 80m depth (hydrostatic pressures of 130 psi or 8.9 x 105 Pa). Although other engineering seismic guns which fire blank or projectile sources are available, they are for near-surface shots and are not meant to be used for downhold seismic surveys in water-filled boreholes. The EDG was designed primarily for checkshot surveys (well travel-time surveys) and high-quality reflection/refraction tests, but potential applications include shallow vertical seismic profiling and borehole to borehole or borehole to surface tomography, as well as optimum offset and common midpoint seismic reflection surveys. The EDG consists off four steel subassemblies: (1) chamber; (2) breech; (3) pipe; and (4) hanger. A blank 8-gauge electrical shell is held by the chamber and is detonated by an electrode located inside the breech. O-ring seals prevent water from entering the breech and causing short circuits. The breech is screwed into a pipe which is also fitted with o-ring seals to keep the internal wiring dry. A hanger subassembly provides a convenient attaching point for the hoist cable. Arming of the EDG with an explosives blaster occurs only after lowering to operating depth. The EDG has been tested with various size black powder loads up to 750 grains. Frequency bandwidth and repeatability tests were carried out under saturated conditions in a fluvial and lacustrine sedimentary section. These preliminary tests show significant frequency content in the 25-200 Hz band (peak near 100 Hz) for reflections from depths of 150-300 m, and acceptable waveform repeatability for different shot records obtained with identical geometry and acquisition parameters

Angular Momentum Transport by MHD Turbulence in Accretion Disks: Gas Pressure Dependence of the Saturation Level of the Magnetorotational Instability

The saturation level of the magnetorotational instability (MRI) is investigated using three-dimensional MHD simulations. The shearing box approximation is adopted and the vertical component of gravity is ignored, so that the evolution of the MRI is followed in a small local part of the disk. We focus on the dependence of the saturation level of the stress on the gas pressure, which is a key assumption in the standard alpha disk model. From our numerical experiments it is found that there is a weak power-law relation between the saturation level of the Maxwell stress and the gas pressure in the nonlinear regime; the higher the gas pressure, the larger the stress. Although the power-law index depends slightly on the initial field geometry, the relationship between stress and gas pressure is independent of the initial field strength, and is unaffected by Ohmic dissipation if the magnetic Reynolds number is at least 10. The relationship is the same in adiabatic calculations, where pressure increases over time, and nearly-isothermal calculations, where pressure varies little with time. Our numerical results are qualitatively consistent with an idea that the saturation level of the MRI is determined by a balance between the growth of the MRI and the dissipation of the field through reconnection. The quantitative interpretation of the pressure-stress relation, however, may require advances in the theoretical understanding of non-steady magnetic reconnection.Comment: 45 pages, 5 tables, 17 figures, accepted for publication in Ap

Temperature-dependent Hall scattering factor and drift mobility in remotely doped Si:B/SiGe/Si heterostructures

Hall-and-Strip measurements on modulation-doped SiGe heterostructures and combined Hall and capacitance–voltage measurements on metal-oxide-semiconductor (MOS)-gated enhancement mode structures have been used to deduce Hall scattering factors, rH, in the Si1 – xGex two-dimensional hole gas. At 300 K, rH was found to be equal to 0.4 for x = 0.2 and x = 0.3. Knowing rH, it is possible to calculate the 300 K drift mobilities in the modulation-doped structures which are found to be 400 cm2 V – 1 s – 1 at a carrier density of 3.3 × 1011 cm – 2 for x = 0.2 and 300 cm2 V – 1 s – 1 at 6.3 × 1011 cm – 2 for x = 0.3, factors of between 1.5 and 2.0 greater than a Si pMOS control

Holocene Glaciation of the Arrigetch Peaks, Brooks Range, Alaska

Eleven cirque glaciers and associated deposits within the granitic Arrigetch Peaks of the west-central Brooks Range face north, minimizing insolation. Shading by surrounding mountainous terrain decreases insolation on these landforms even more significantly, favoring the formation of glacier-cored moraines. Comparison of glacier photographs taken in 1911, 1962, and 1979 reveals a record of decelerating recession. Geomorphic and lichenometric mapping suggests at least three to possibly eight phases of Holocene glacial expansion. These date between ~5000 and 300 yr B.P., based on the application of a central Brooks Range Rhizocarpon geographicum growth curve