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Soil detachment and sediment transport brought about by raindrops and overland flow are factors to be considered when using physically-based soil erosion simulation models. A raindrop-induced soil detachability parameter can be induced by integrating estimated soil detachment from a single raindrop impact over all raindrops while a raindrop-induced transportability parameter can be derived by dividing the measured sediment delivery rates with the product of rainfall rate and unit effective kinetic energy.

Amodel of soil erosion by water that predicts the level of soil detachment by multiple raindrops beating on a naked soil surface relies on indicators of a soil-strength-dependent single-drop detachment model, and a bivariate raindrop-size distribution function. Raindrop detachment rate, when shown as a linear and nonlinear function of intensity, results in equations that associate the indications of soil detachment rate versus intensity functions to other parameters of the single-drop detachment model.

Soil water retention and transport functions are needed to model infiltration and redistribution of water in reclaimed mineland profiles. Besides primary particles of sand, silt, clay, and rock fragments, some mineland soil profiles in west-central North Dakota also contain lignite coal fragments ranging in sizes from < 1 to about 300 mm or more. The objective of this study was to evaluate the water retention properties of soil mixed with coal fragments. For preliminary investigations in the laboratory, disturbed soil and coal samples of sizes < 2.0 mm were used. Two types of coal samples, one commercial lignite with high water repellency and the other a degraded lignite with low water repellency, were mixed with three types of soils. The soil samples collected from subsoil and minespoil materials of reclaimed minelands included a sandy loam, a loam, and a sodic silty clay loam (equivalent to premine B and C horizons of Straw loam, a fine-loamy, mixed Cumulic Haploboroll). Air-dry samples of soil and coal were thoroughly mixed and bulk mixtures with coal contents of 5, 10, 15, 25, and 50% by oven-dry weight were produced. The subsamples of the components and the mixtures were wetted with water and desorbed at air pressures ranging from 5 to 1500 kPa. Water contents of the mixtures, in general, were linearly proportional to the coal contents. From the soil water content vs. pressure head relationships of ingredient soil and coal samples, volumetric water contents of soil-coal mixtures were predicted by using mass and volume balance interpolation equations. At all pressures heads, the predicted volumetric water contents approximated the measured values with a high degree of accuracy.

06-1633 Kar, T., P.P. Sharma, and M.L. Munjal. Analysis of multiple-duct variable area perforated tube resonators. International Journal of Acoustics and Vibration (Russia) 11(1):19-26, March 2006 (www. iiav.org). KEYWORDS: algorithms, [...]

Hydro-energy has been universally accepted as the most reliable and cost-effective renewable energy source. Among the several types of hydro-power-generation methods, small hydro-power (SHP) system plays a major role in meeting power requirements of remote, isolated hilly areas in a de-centralized manner by tapping water streams, rivulets and canals of small discharge. An SHP system can function either connected with the grid, where it can feed surplus power generated to the grid or as an independent/stand-alone isolated system exclusively meeting the local demands of remote locations. The authors in this article have made an attempt to summarize the literature available in this context and have come out with a review paper which is believed to be of immense benefit to researchers and policy/decision-makers in arriving at effective solutions to the problems in the related field. [ABSTRACT FROM AUTHOR]

Abstract: Increase in alfalfa (Medicago sativa L.) production for energy (gasification of stems) and protein supplement (from leaves) has been proposed for the upper Midwestern United States, an area where corn (Zea mays L.) in rotation with soybean (Glycine max L.) is the predominant crop sequence. This study was undertaken to assess the impact on runoff and water quality, especially for the loss of oxygen demanding material with snowmelt. Four field size watersheds were instrumented at Morris, Minnesota, USA on a rolling prairie landscape. Snowmelt runoff from each watershed was measured with two flumes with overlapping ranges arranged in series. An automatic water sampler collected runoff samples for chemical analysis. Oxygen demand was used as a surrogate for reduced carbon. Water samples were analyzed for total solids, biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Based on the results of snowmelt events of 1997, 1998, and 1999, the alfalfa fields yielded more runoff than corn-soybean fields. The loss of total solids was more consistent from alfalfa fields. Total solids losses interacted with crop and year. Compared to alfalfa fields losses were less following soybeans and greater following corn. On average losses were similar between alfalfa and corn-soybean fields. Runoff from alfalfa fields contained about four times more BOD than corn-soybean fields. Although not statistically significant due to only two replications, there was a similar trend for COD. This study shows that although losses of total solids in snowmelt from alfalfa fields was similar to corn-soybean fields, there can be increased losses of oxygen demanding materials. [Copyright &y& Elsevier]