Description: The purpose of this study is to "establish a data base and methodology for classifying...the streams of the Roanoke Basin into a hierarchy of ecological systems" and to "establish evaluative criteria and methodology for classifying and ranking streams within the ecological systems relative to their state of environmental quality" (p. R1).

Description: This article discusses projectile-charge-state dependence of target L-shell ionization by 1.86-MeV/amu and silicon ions and 1.8-MeV/amu chlorine ions. Lα x-ray-production cross sections have been measured for solid targets of ₆₀Nd, ₆₇Ho, and ₇₉Au for 1.86-MeV/amu ₉¹⁹F and ₁₄²⁸Si, and 1.8-MeV/amu ₁₇³⁵Cl ions as a function of the incident charge state. From the projectile-charge-state dependence of the cross sections, both direct-ionization and electron-capture contributions were extracted for a comparison to Coulomb ionization theories. The data provide supporting evidence for the theory of electron capture with a reduced binding effect. With standard fluorescence and Coster-Kronig yields uncorrected for multiple-ionization effects, the direct ionization theories did not simultaneously reproduce the projectile-Z₁ and target-Z₂ dependences of the data.

Description: The vertical oriented room divider depicts a landscape type of scene with moon and sun type shapes floating through and among wave like shapes. The colors are in a range from warm orange and pale yellow to blue greens.