The economics of using sediment-entrapment reduction measures in lake and reservoir design

One of the most important impacts of building and maintaining a reservoir is the loss of storage capacity caused by sediment deposition behind the dam. Sediment deposition in the reservoir reduces the water storage volume and decreases or even negates the utility of the dam, and deteriorates the water quality. The loss of utility of a reservoir as a result of sedimentation or siltation can be considered an economic, environmental, and even a design failure. The objective of this study was to investigate, through an extensive literature search, the suitability and efficiency of several reservoir sedimentation reduction measures practiced in small- and medium-sized lakes. Some of the methods successfully used for reducing sediment entrapment in reservoirs were watershed management, building check dams, bypassing sediment-laden flows, using density currents, flood flushing, drawdown flushing, flushing and emptying, siphoning, and dredging. The mitigation and operation methods so identified were evaluated with respect to their rate of success, cost, environmental impacts, and ease of implementation or retrofitting. The economies expected in using the identified alternative mitigative measures versus more conventional reservoir design were investigated in terms of reduced initial cost of reservoir and/or dredging costs.U.S. Department of the InteriorU.S. Geological SurveyOpe

Managed flood storage option for selected levees along the lower Illinois River for enhancing flood protection, agriculture, wetlands, and recreation: Second report, validation of the UNET model for the lower Illinois River

"March 1997.""A division of the Illinois Department of Natural Resources.

Low-flow estimates for Cedar Creek at Galesburg, Illinois

"September 1995.""Prepared for the Galesburg Sanitary District, Galesburg, Illinois.

Benthic sediment conditions and remediation alternatives for Horseshoe Lake, Alexander County

"Office of River Water Quality.""February 1997.""Office of Surface Water Resources: Systems, Information & GIS.""Contract Report 607"--Cover."Prepared for the Division of Fisheries, Illinois Dept. of Natural Resources.

Microflares in accretion disks

We have investigated the phenomenon of explosive chromospheric evaporation from an accretion disk as a mechanism for fast variability in accreting sources such as low mass X-ray binaries and active galactic nuclei. This has been done in the context of advection dominated accretion flows, allowing both high and low states to be considered. This mechanism can in principle produce sub-millisecond timescales in binaries and sub-minute timescales in active galaxies. However, even considering the possibility that large numbers of these microflares may be present simultaneously, the power emitted from these microflares probably amounts to only a small fraction of the total X-ray luminosity.Comment: 5 pages, 1 figure, uses older A&A class file; accepted for publication in A&

Reversible plasticity in amorphous materials

A fundamental assumption in our understanding of material rheology is that when microscopic deformations are reversible, the material responds elastically to external loads. Plasticity, i.e. dissipative and irreversible macroscopic changes in a material, is assumed to be the consequence of irreversible microscopic events. Here we show direct evidence for reversible plastic events at the microscopic scale in both experiments and simulations of two-dimensional foam. In the simulations, we demonstrate a link between reversible plastic rearrangement events and pathways in the potential energy landscape of the system. These findings represent a fundamental change in our understanding of materials--microscopic reversibility does not necessarily imply elasticity.Comment: Revised pape

Effect of micronutrients on leaf composition, fruit quality and yield of Kinnow mandarin

Effect of micronutrients on leaf composition, quality parameters and fruit yield of Kinnow mandarin was studied at Regional Research Station, Abohar. Foliar application of 1000 ppm Zn + 1000 ppm Mn on Kinnow mandarin during the end of April and mid of August gave maximum fruit yield (862 fruits / tree) and good quality fruits (Higher TSS/Acid: 14.23) by correcting these micronutrient deficiencies. Therefore, application of this dose of micronutrient combination will improve yield and fruit quality in Kinnow mandarin by correcting the deficiencies of these micronutrients as a result of which the orchardist will be economically benefited

City of Charleston public water supply: analysis of drought yields from the Charleston side-channel reservoir

"Prepared for the City of Charleston.""April 1996.

Considerations in water use planning for the Fox River

"September 1995."Cover title."SWS Contract Report 586.""Prepared for the Illinois Dept. of Transportation, Division of Water Resources."Includes bibliographical references