Capillary pressure-saturation data obtained for unconsolidated porous media with different liquids are examined to investigate the effects of clay-liquid interactions on liquid retention. Liquid retention functions are assumed to reflect the effective pore-size distributions. The hydraulic variables, capillary pressure and saturation, are transformed to account for changes in liquid retention...
Sediments are the major compartment in aquatic environments for many materials of toxic or nutrient concern. The lack of knowledge of the phase associations of toxic metals in sediments is the largest deficiency in our understanding of the environmental hazard posed by metal contamination. This study examined the sedimentary partitioning...
Andesitic and rhyolitic magmatism was active during the mid-
Tertiary (Early Miocene) of the Ash Peak area, southeastern Arizona.
Andesitic magmas of similar composition both preceded and followed the
low- and high-silica rhyolitic magmas. The changes from andesitic to
rhyolitic and back to andesitic volcanism is postulated to be the...
The relationships among total water potential (psi), osmotic potential ([pi]), pressure potential (P), and relative water content (R*) were determined during four consecutive soil drying cycles for shoots of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings. In each cycle, seedlings were sampled for pressure-volume determinations as soil water was depleted gradually...
The dynamics of stands In old-growth ponderosa pine (Pinus
ponderosa) forests on the eastern flank of the central Oregon
Cascades are Investigated. Age structure and spatial pattern of
ponderosa pine within the Pringle Falls Experimental Forest
Research Natural Area coupled with the fire history of the area
aid In Interpreting...
The bluffs and plateaus of the eastern Columbia River are floristically rich and ecologically intricate. A previous descriptive study of the unique scabland vegetation on the Gov. Tom McCall Preserve at Rowena Plateau in Oregon included delineation of several distinct or intergrading native and non-native vegetation units. In this study...
A new class of nearshore waves based on the shear instability of a steady longshore current is discussed. The dynamics depend on the conservation of potential vorticity but with the background vorticity field, traditionally the role of Coriolis in larger scale flows, supplied by the shear structure of the longshore...
The kinetic mechanism of the unidirectional
H2-oxidizing hydrogenase from soybean nodule bacteroids has
been investigated with highly purified enzyme. Measurements
of the K, for H2 vary from 0.97 to 2.6 pM, and the K,,, for
methylene blue varies from 6 to 17 pM. With H2 and
methylene blue as substrates,...