No abstract

No abstract

No abstract

No abstract

No abstract

The two-filter method described by Thomas and LeClare was used to investigate the effects of trace concentrations of nitric oxide and nitrogen dioxide in dry nitrogen on the diffusion coefficient of radium A (polonium-218). Charged radium A was neutralized in 10 parts per million (ppm) nitrogen dioxide in dry nitrogen, in 8.3 ppm nitric oxide in dry 92 percent nitrogen and 8 percent oxygen, and in nitrogen with 20 and 80 percent relative humidity. No neutralization was seen in dry nitrogen, dry oxygen, dry air, or 10 ppm nitric oxide in dry nitrogen. The diffusion coefficient of the neutral radium A species was found to be 0.079 square centimeters per second, regardless of the relative humidity of the nitrogen gas atmosphere. Lower values were observed for charged species.

No abstract

Efforts to restore the Lower Mississippi Alluvial Valley's forests have not achieved desired levels of ecosystem services production. We examined how the variability of returns and the flexibility to change or postpone decisions (option value) affects the economic potential of forestry and agroforestry systems to keep private land in production while still providing ecosystem services. A real options analysis examined the impact of flexibility in decision making under agriculture, forestry, and agroforestry and demonstrated that adoption of forestry or agroforestry systems is less feasible than would be predicted by deterministic capital budgeting models.