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Hysteresis in the relation between water saturation and matric potential is generally regarded as a basic aspect of unsaturated porous media. However, the nature of an upper length scale limit for saturation hysteresis has not been previously addressed. Since hysteresis depends on whether or not capillary rise occurs at the grain scale, this criterion was used to predict required combinations of grain size, surface tension, fluid-fluid density differences, and acceleration in monodisperse systems. The Haines number ( Ha), composed of the aforementioned variables, is proposed as a dimensionless number useful for separating hysteretic ( Ha < 15) versus nonhysteretic ( Ha > 15) behavior. Vanishing of hysteresis was predicted to occur for grain sizes greater than 10.4 ± 0.5 mm, for water-air systems under the acceleration of ordinary gravity, based on Miller-Miller scaling and Haines' original model for hysteresis. Disappearance of hysteresis was tested through measurements of drainage and wetting curves of sands and gravels and occurs between grain sizes of 10 and 14 mm (standard conditions). The influence of surface tension was tested through measurements of moisture retention in 7 mm gravel, without and with a surfactant (sodium dodecylbenzenesulfonate (SDBS)). The ordinary water system ( Ha = 7) exhibited hysteresis, while the SDBS system ( Ha = 18) did not. The experiments completed in this study indicate that hysteresis in moisture retention relations has an upper limit at Ha = 16 ± 2 and show that hysteresis is not a fundamental feature of unsaturated porous media. [ABSTRACT FROM AUTHOR]

Studies the in situ reduction of chromium(VI) in heavily contaminated soils through organic carbon amendment. Ingredients of solutions designed to accelerate the reduction of chromium in soils; Synergistic effects sustained in whole soil systems.

Focuses on the distribution of chromium (Cr) contamination and microbial activity in soil aggregates. Occurrence of the reduction of soluble Cr(VI) to insoluble Cr(III); Development of Cr diffusion fronts; Observation of higher microbial activity; Illustration of Cr(VI) reduction in soil aggregates.

Some environmentally sensitive unsaturated zone sediments, such as those underlying radioactive waste tanks in Hanford (Washington State), contain large fractions of gravels and coarse sands. Coarse, granular media are also included in designs of engineered capillary barriers for subsurface waste isolation. Thus knowledge of the unsaturated hydraulic properties of gravels is needed to understand flow and transport in these critical settings. When standard methods for measuring moisture characteristics or water retention relations are used for gravels, corrections are needed in the near-zero region of matric (pressure) potentials. The need for correction results from gravity stratification of saturation profiles within even short sample columns. Such a correction method was developed and used to determine drainage curves for Hanford gravels having characteristic grain sizes of 8.0-9.5, 4.8-5.3, and 2.0-2.4 mm. In 30 mm tall sample columns, gravity corrections were essential for the 9 and 5 mm gravels and less significant for the 2 mm gravel. Validity of the correction method was demonstrated through accurately reconstructing average column saturation-potential relations from their predicted local saturation-potential relations. The method and results presented here are part of an ongoing study on Hanford gravels and on limits to classical unsaturated hydraulic scaling encountered at large grain sizes. [ABSTRACT FROM AUTHOR]

The present study empirically tests the existence, universality, and specific locus of the generation gap through a comparative intrafamily study of fathers and their college-age children. Intrafamily agreement-disagreement coefficients are computed between fathers and offspring on their rankings of eight important contemporary issues, and analyzed via seven independent variables. Results show first that a general consensus level characterizes fathers and offspring; and, second, that specific foci of disagreement emerge--related to sex and year-in-college of the student and to the working-class origins of the father. Hence the generation gap is apparently not a ubiquitous, universal family event. [ABSTRACT FROM AUTHOR]

R2606 --> The ongoing severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pandemic requires treatments with rapid clinical translatability. As such, several studies have screened FDA‐approved drugs in silico at a limited number of classical antiviral sites for anti‐SARS‐CoV‐2 activity. We hypothesized that an extensive in‐silico drug repurposingscreen against a wide range of SARS‐COV‐2 proteins could identify novel antiviral drugs and help elucidate mechanisms of drug action of hits from in vitro screens. We selected 48 known or predicted drug sites across 23 SARS‐COV‐2 proteins using homology models and crystal structures based on known antiviral drug sites (i.e., polymerase or protease active sites), computational predictions, and protein‐protein interfaces. Then, using the software GOLD, we docked 1268 FDA‐approved small‐molecule drugs into each site. Virtual hits were prioritized based on their anti‐SARS‐COV‐2 activity found in a recent phenotypic drug‐repurposing screen using human huh‐7 epithelial cells. This resulted in the identification of a range of drugs acting at a variety of targets and sites. Several compelling drug/site pairs were identified, including sites on the Spike protein, which mediates viral entry. For example, we identified hits with anti‐SARS‐CoV2 activity in vitro, at a putative allosteric site that incorporates two functionalities required for viral entry, namely the Spike S2' cleavage site – which a host protease must cleave for viral entry, and the critical 'fusion peptide' domain – which injects itself into the host membrane during viral entry. Moreover, these in silico results identify possible mechanisms for in vitro drug repurposing hits, potential additional targets for known drugs, and a starting point to test drug combinations that may have better activity by acting at different steps in the viral cycle activity in combination than on their own. 8.5.5 [ABSTRACT FROM AUTHOR]