Thermal Equilibration of 176-Lu via K-Mixing

In astrophysical environments, the long-lived (\T_1/2 = 37.6 Gy) ground state of 176-Lu can communicate with a short-lived (T_1/2 = 3.664 h) isomeric level through thermal excitations. Thus, the lifetime of 176-Lu in an astrophysical environment can be quite different than in the laboratory. We examine the possibility that the rate of equilibration can be enhanced via K-mixing of two levels near E_x = 725 keV and estimate the relevant gamma-decay rates. We use this result to illustrate the effect of K-mixing on the effective stellar half-life. We also present a network calculation that includes the equilibrating transitions allowed by K-mixing. Even a small amount of K-mixing will ensure that 176-Lu reaches at least a quasi-equilibrium during an s-process triggered by the 22-Ne neutron source.Comment: 9 pages, 6 figure

Kepone in the James River Estuary: Past, Current and Future Trends

In late 1975, a manufacturing facility in Hopewell, VA had not only exposed workers to the chlorinated pesticide, Kepone, but had also severely contaminated the James River estuary. To assess the potential risk to the public, Virginia initiated a finfish-monitoring program in late 1975. Over the next 40 years over 13,000 samples were collected from the James River and Chesapeake Bay and analyzed for Kepone. Kepone production was eventually banned worldwide. The average Kepone concentrations found in most species began falling when the production of Kepone ended, but the averages remained over the action limit of 0.3 mgkg-1 until the early 1980s. By 1988, few fish contained average Kepone concentrations greater than the action limit. Kepone was still detected (\u3e0.01 mgkg-1 wet weight) in the majority of white perch and striped bass samples taken from the James River in 2009 and a fish consumption advisory is still in effect over forty years after the source of contamination was removed. Due to state budget cuts, monitoring of Kepone has not been conducted since 2009. As part of its 40th Anniversary, the Virginia Environmental Endowment -- which was established as part of the Kepone pollution court settlement in 1977 -- requested that VIMS conduct an updated study of the current levels of Kepone in the James River

A novel antibody-based biosensor method for the rapid measurement of PAH contamination in oysters

Conventional PAH analytical methods are time-consuming and expensive, limiting their utility in time sensitive events (i.e. oil spills and floods) or for widespread environmental monitoring. Unreliable and inefficient screening methods intended to prioritize samples for more extensive analyses exacerbate the issue. Antibody-based biosensor technology was implemented as a quantitative screening method to measure total PAH concentration in adult oysters (Crassostrea virginica) — a well-known bioindicator species with ecological and commercial significance. Individual oysters were analyzed throughout the historically polluted Elizabeth River watershed (Virginia, USA). Significant positive association was observed between biosensor and GC–MS measurements that persisted when the method was calibrated for different regulatory subsets of PAHs. Mapping of PAH concentrations in oysters throughout the watershed demonstrates the utility of this technology for environmental monitoring. Through a novel extension of equilibrium partitioning, biosensor technology shows promise as a cost-effective analysis to rapidly predict whole animal exposure to better assess human health risk as well as improve monitoring efforts

Characteristics of the main components of artistic and aesthetic environment of the school

The article presents the structure and content of the artistic and aesthetic environment of the school. Artistic and aesthetic environment - a concept that is in the stage of registration in a complex multi-level definition. In modern researches its types, components, elements, possibilities of influence on various spheres of human activity are studied. The purpose of the article is to reveal the pedagogical potential of the artistic and aesthetic environment of the school in the development of the student's personality.В статье дается характеристика структуре и содержанию художественно-эстетической среды школы

Manure Application Timing Drives Energy Absorption for Snowmelt on an Agricultural Soil

Reducing agricultural runoff year-round is important, in particular during snowmelt events on landscapes that receive wintertime applications of manure. To help inform manure guidelines, process-level data are needed that link management scenarios with the complexity of snowmelt, hence runoff. Albedo and radiative energy fluxes are strong drivers of thaw, but applying these mechanistic measurements across multiple, plot-scale management treatments over time presents a logistical challenge. The objective of this study was to first develop a practical field approach to estimate winter albedo in plot-scale field research with multiple management scenarios. The second objective was to quantify the radiative drivers of snowmelt by measuring fluxes after wintertime liquid manure application. Six management treatments were tested in south-central Wisconsin during the winters of 2015–2016 and 2016–2017 with a complete factorial design: three manure application timings (early December, late January, and unmanured) and two tillage treatments (conventional tillage versus no-tillage). A multiple linear regression model was developed to estimate albedo with digital imagery and readily-obtained site characteristics. Manure timing had a significant effect on radiative energy fluxes and tillage was secondary. January applications of liquid manure produced an immediate and lasting decrease in albedo, which resulted in greater net radiation absorbed by snowpack and subsequent energy available for snowmelt. Later applications of liquid manure accelerated snowmelt, which increased runoff losses and posed a challenge for nutrient retention from the liquid manure during thaw

Efficacy of sediment remediation efforts on PAH contaminant flux via porewater advection at the sediment-surface water interface

Groundwater advection at the sediment-surface water interface is an important biogeochemical mechanism controlling the transport and bioavailability of contaminants in estuaries. At sites along the Elizabeth River (VA, USA) where the subterranean environment is heavily contaminated with polycyclic aromatic hydrocarbon (PAH)-rich dense non-aqueous phase liquid (DNAPL), consideration of groundwater-surface water dynamics and associated chemical exchange is critical for effective remediation. Preliminary data suggest that porewater advection in permeable sediments at this location is controlled by a host of physical forcing mechanisms that correspond with total flow estimates of up to 15,000 centimeters/year. Here, the efficacy of sediment remediation strategies, including dredging and capping DNAPL-laden sediments as well as implantation of a groundwater-blocking sheet pile wall, was evaluated with respect to groundwater and contaminant fluxes using naturally-occurring radionuclide tracers and a PAH antibody-based biosensor. Comparison of these data with results from similar analyses conducted at neighboring sites targeted for future remediation was provided to environmental managers to help guide future remediation efforts. Preliminary results revealed total PAH concentrations of up to \u3e400 μg/L in groundwater at subsurface depths up to 80 centimeters in the unremediated zone and corresponding salinity measurements of 5 –8 ppt, compared with a surface water salinity of 18 ppt. Groundwater samples from sediment depths reaching 120 centimeters at the recently remediated location had comparably low salinities and elevated PAH concentrations. These data provided strong evidence for the role of fresh groundwater contaminated with DNAPL as a major mode of PAH transport and suggest the need to devise additional, innovative strategies to mitigate porewater-associated contaminant flux

Linking Nutrient Transport to Soil Physical Processes During Freeze/Thaw Events to Promote Wintertime Manure Management, Nutrient Use Efficiency, and Surface Water Quality.

The application of dairy manure to the landscape during winter is a longstanding practice for farms in the Midwestern United States and other temperate regions. Practical motivations behind winter spreading include affordability, availability of time, and the reduced risk of compaction from farm equipment on frozen soils. Wintertime manure applications, however, coincide with environmental conditions that are prone to runoff and accelerate nutrient losses from agricultural fields. Understanding the nutrient dynamics in response to winter-applied manure is especially important to Wisconsin, a leading state in dairy production, where up to 75% of annual runoff volumes occur on frozen and thawing soils. The high potential for winter runoff, hence nutrient transport, has prompted revisions to winter manure regulations, yet little conclusive data exist to guide these changing standards

Temperature and Manure Placement in a Snowpack Affect Nutrient Release from Dairy Manure During Snowmelt

Agricultural nutrient management is an issue due to N and P losses from fields and water quality degradation. Better information is needed on the risk of nutrient loss in runoff from dairy manure applied in winter. We investigated the effect of temperature on nutrient release from liquid and semisolid manure to water, and of manure quantity and placement within a snowpack on nutrient release to melting snow. Temperature did not affect manure P and NH4–N release during water extraction. Manure P release, but not NH4–N release, was significantly influenced by the water/manure solids extraction ratio. During snowmelt, manure P release was not significantly affected by manure placement in the snowpack, and the rate of P release decreased as application rate increased. Water extraction data can reliably estimate P release from manure during snowmelt; however, snowmelt water interaction with manure of greater solids content and subsequent P release appears incomplete compared with liquid manures. Manure NH4–N released during snowmelt was statistically the same regardless of application rate. For the semisolid manure, NH4–N released during snowmelt increased with the depth of snow covering it, most likely due to reduced NH3 volatilization. For the liquid manure, there was no effect of manure placement within the snowpack on NH4–N released during snowmelt. Water extraction data can also reliably estimate manure NH4–N release during snowmelt as long as NH3 volatilization is accounted for with liquid manures for all placements in a snowpack and semisolid manures applied on top of snow

Resonant forcing of select degrees of freedom of multidimensional chaotic map dynamics

We study resonances of multidimensional chaotic map dynamics. We use the calculus of variations to determine the additive forcing function that induces the largest response, that is, the greatest deviation from the unperturbed dynamics. We include the additional constraint that only select degrees of freedom be forced, corresponding to a very general class of problems in which not all of the degrees of freedom in an experimental system are accessible to forcing. We find that certain Lagrange multipliers take on a fundamental physical role as the efficiency of the forcing function and the effective forcing experienced by the degrees of freedom which are not forced directly. Furthermore, we find that the product of the displacement of nearby trajectories and the effective total forcing function is a conserved quantity. We demonstrate the efficacy of this methodology with several examples.Comment: 11 pages, 3 figure