Symbolic dynamics I. Finite dispersive billiards

Orbits in different dispersive billiard systems, e.g. the 3 disk system, are mapped into a topological well ordered symbol plane and it is showed that forbidden and allowed orbits are separated by a monotone pruning front. The pruning front can be approximated by a sequence of finite symbolic dynamics grammars.Comment: CYCLER Paper 93Jan00

Conservation Reserve Program: Environmental Benefits Update

This paper presents the methodology, assumptions, and data used to generate regional and national environmental benefit estimates of the USDA’s Conservation Reserve Program (CRP). It’s assumed that, without the program, production and conservation practices on CRP lands would be the same as those used on surrounding lands. When range and forest lands are (are not) included as land-use options, 54 (71) percent of the CRP land would be in crop production—which is consistent with past analyses. Soil erosion would be 222 to 248 million tons per year—about 11 percent—higher than the current level. Benefits are estimated by applying environmental benefit models, estimated in previous analyses, to the CRP’s estimated effect on erosion and wildlife habitat. Nationally, the CRP is estimated to provide $1.3 billion in annual benefits, which represents 75 to 80 percent of the program’s cost. In seven of the 10 USDA Farm Production Regions, the CRP’s environmental benefits exceed costs. Thus, reallocating acreage to these regions could increase net program benefits. However, because many benefits could not be estimated, one cannot conclude that regional and national benefits do not exceed costs.Resource /Energy Economics and Policy,

Great prospects for fiber optics sensors

Fiber optic sensors provide noise immunity and galvanic insulation at the measurement point. Interest in such sensors is increasing for these reasons. In the United States sales are expected to increase from 12 million dollars in 1981 to 180 million in 1991. Interferometric sensors based on single modus fibers deliver extremely high sensitivity, while sensors based on multi-modus fibers are more easily manufactured. The fiber optic sensors which are available today are based on point measurements. Development of fiber optic sensors in Norway is being carried out at the Central institute and has resulted in the development of medical manometers which are now undergoing clinical testing

The Viability of Creating Wetlands for the Sale of Carbon Offsets

This analysis estimates the profitability of restoring wetlands for the sale of carbon offsets. Results indicate that about 7% to 12% of the recently restored grassed wetlands of the prairie pothole and high plains regions and 20% to 35% of the forested wetlands of the Mississippi alluvial valley and Gulf-Atlantic coastal flats regions could have carbon offset values that exceed the cost of restoring the wetland and the opportunity cost of moving the land out of agricultural production. Given the uncertainties, the analysis applies conservative estimates of wetlands’ costs, offset prices, and wetlands’ effects on greenhouse gases.carbon markets, carbon sequestration, offsets, wetland restoration, Environmental Economics and Policy, Land Economics/Use,

Restoration of Wetland Services: Economic Gains to the Farmland Owner

The objective of this analysis is to describe and, if possible, measure gains that farmland owners may have seen because of the public's demand for wetland services. To do so, we first consider landowners' ability to directly sell onsite (hunting, fishing, wildlife viewing) and offsite (water quality, groundwater recharge, etc.) wetland services. We found little evidence that landowners sell wetland services. We then consider farmland owners' gains from the mitigation banking system. We found that, with less than 200 approved mitigation banks on farmland, farmland owners had some but limited opportunities to participate in mitigation markets. Finally, we consider landowners' gains from the sale of wetland easements through the USDA's Wetland Reserve Program (WRP). Although we are unable to quantify any gains, the popularity of the program suggests that landowners do gain by participating - since the mid-1990's, more landowners have tried to enroll than program limits allow. Furthermore, two factors suggest that WRP gains are widespread. First, WRP easements have been sold in every State. And second, easement prices have increased over time which may indicate that owners of higher-valued lands may be seeing opportunities to participate.Land Economics/Use,