TOPEX satellite concept. TOPEX option study report

Candidate bus equipment from the Viking, Applications Explorer Mission, and Small Scientific Satellite programs for application to the TOPEX mission options is assessed. Propulsion module equipment and subsystem candidates from the Applications Explorer Mission satellites and the Small Scientific Satellite spacecraft are evaluated for those TOPEX options. Several subsystem concepts appropriate to the TOPEX options are described. These descriptions consider performance characteristics of the subsystems. Cost and availability information on the candidate equipment and subsystems are also provided

An Inverse Scattering Transform for the Lattice Potential KdV Equation

The lattice potential Korteweg-de Vries equation (LKdV) is a partial difference equation in two independent variables, which possesses many properties that are analogous to those of the celebrated Korteweg-de Vries equation. These include discrete soliton solutions, Backlund transformations and an associated linear problem, called a Lax pair, for which it provides the compatibility condition. In this paper, we solve the initial value problem for the LKdV equation through a discrete implementation of the inverse scattering transform method applied to the Lax pair. The initial value used for the LKdV equation is assumed to be real and decaying to zero as the absolute value of the discrete spatial variable approaches large values. An interesting feature of our approach is the solution of a discrete Gel'fand-Levitan equation. Moreover, we provide a complete characterization of reflectionless potentials and show that this leads to the Cauchy matrix form of N-soliton solutions

Farm practices and their effects on farm earnings

Includes bibliographical references

Comparing Wealth Effects: The Stock Market Versus the Housing Market

We examine the link between increases in housing wealth, financial wealth, and consumer spending. We rely upon a panel of 14 countries observed annually for various periods during the past 25 years and a panel of U.S. states observed quarterly during the 1980s and 1990s. We impute the aggregate value of owner-occupied housing, the value of financial assets, and measures of aggregate consumption for each of the geographic units over time. We estimate regressions relating consumption to income and wealth measures, finding a statistically significant and rather large effect of housing wealth upon household consumption.

Wealth Effects Revisited 1978-2009

We re-examine the link between changes in housing wealth, financial wealth, and consumer spending. We extend a panel of U.S. states observed quarterly during the seventeen-year period, 1982 through 1999, to the thirty-one year period, 1978 through 2009. Using techniques reported previously, we impute the aggregate value of owner-occupied housing, the value of financial assets, and measures of aggregate consumption for each of the geographic units over time. We estimate regression models in levels, first differences and in error-correction form, relating per capita consumption to per capita income and wealth. We find a statistically significant and rather large effect of housing wealth upon household consumption. This effect is consistently larger than the effect of stock market wealth upon consumption. This reinforces the conclusions reported in our previous analysis. In contrast to our previous analysis, however, we do find -- based on data which include the recent volatility in asset markets -- that the effects of declines in housing wealth in reducing consumption are at least as large as the effects of increases in housing wealth in increasing the course of household consumption.Consumption, Nonfinancial wealth, Housing market, Real estate

Performance of cylindrical converters with preferred-crystal-orientation emitters of chemically vapor deposited tungsten

Design and evaluation of cylindrical out-of-pile thermionic converter test vehicle to determine performance of tungsten emitters with preferred crystal orientatio

Long-term electrode behavior during treatment of arsenic contaminated groundwater by a pilot-scale iron electrocoagulation system.

Iron electrocoagulation (Fe-EC) is an effective technology to remove arsenic (As) from groundwater used for drinking. A commonly noted limitation of Fe-EC is fouling or passivation of electrode surfaces via rust accumulation over long-term use. In this study, we examined the effect of removing electrode surface layers on the performance of a large-scale (10,000 L/d capacity) Fe-EC plant in West Bengal, India. We also characterized the layers formed on the electrodes in active use for over 2 years at this plant. The electrode surfaces developed three distinct horizontal sections of layers that consisted of different minerals: calcite, Fe(III) precipitates and magnetite near the top, magnetite in the middle, and Fe(III) precipitates and magnetite near the bottom. The interior of all surface layers adjacent to the Fe(0) metal was dominated by magnetite. We determined the impact of surface layer removal by mechanical abrasion on Fe-EC performance by measuring solution composition (As, Fe, P, Si, Mn, Ca, pH, DO) and electrochemical parameters (total cell voltage and electrode interface potentials) during electrolysis. After electrode cleaning, the Fe concentration in the bulk solution increased substantially from 15.2 to 41.5 mg/L. This higher Fe concentration led to increased removal of a number of solutes. For As, the concentration reached below the 10 μg/L WHO MCL more rapidly and with less total Fe consumed (i.e. less electrical energy) after cleaning (128.4 μg/L As removed per kWh) compared to before cleaning (72.9 μg/L As removed per kWh). Similarly, the removal of P and Si improved after cleaning by 0.3 mg/L/kWh and 1.1 mg/L/kWh, respectively. Our results show that mechanically removing the surface layers that accumulate on electrodes over extended periods of Fe-EC operation can restore Fe-EC system efficiency (concentration of solute removed/kWh delivered). Since Fe release into the bulk solution substantially increased upon electrode cleaning, our results also suggest that routine electrode maintenance can ensure robust and reliable Fe-EC performance over year-long timescales