Search

Epoxy-coated anchors used for stabilization of the dam at the Occoquan River, Virginia, exhibited more creep movement and seating losses than bare-wire strands due to a difference in the material's behavior. Epoxy-coated anchors have provided double corrosion protection to the dam. Studies conducted by Harza Engineering Co. show that the Post-Tensioning Institute criteria may be unsuitable for epoxy-coated filled strand since it is based on the bare-wire strand. Lift-off tests are the best method for a long-term evaluation of anchor performance.

The details pertaining to the understanding the nature, and properties of a smaller particle, the neutrino, at the new underground laboratories at the Fermi National Accelerator Laboratory, located in Batavia, Illinois, are presented.

A wide range of methods are commonly used to measure deposited fine sediment and quantify substrate quality in rivers as part of bioassessment or monitoring programmes. In this laboratory-based experiment known amounts of three sediment types (sand, topsoil, peat) were added to mesocosms and four methods of measuring deposited fine sediment; turbidity, estimation of released sediment, Turner–Hillis deposited sediment sampler (DSS) and visual estimation of % surface cover were evaluated. The objective of the study was to evaluate which of these methods for estimating deposited sediment best discriminates between levels of deposited fine sediment added and assesses the effects of inter-observer variability between % surface cover estimations. While turbidity measurement and the resuspension method were strongly related to levels of added sediment, it proved difficult using the two methods to resolve differences between adjacent levels of added sediment e.g. 50 g and 100 g. Surface cover estimations were also strongly related to added sediment levels and were better able to distinguish between adjacent levels of added sediment. Furthermore, we found no significant differences between the % surface cover estimations between observers. Results from this laboratory experiment strongly endorse the use of visual estimation of surface cover in field studies. Further work evaluating the turbidity and re-suspension methods under field conditions would also be beneficial. [ABSTRACT FROM AUTHOR]

Highlights: [•] A hydro-environmental model investigated the consequences of closing a power plant. [•] Model simulated water quality for three scenarios before and after closing the plant. [•] Dilution scenario gave better water quality results than direct discharges scenario. [•] Direct discharges scenario showed an increased stratification of the estuary waters. [Copyright &y& Elsevier]

The article discusses the hydrological aspects of the Water Framework Directive (WFD) in Ireland. It says that it looks into the main hydrological data types which include discharge data, precipitation/rainfall, and groundwater levels. It adds that government organizations play key roles in the sponsoring and initiating research to generate knowledge that can be use in implementing the WFD including the Environmental Protection Agency (EPA), National Roads Authority (NRA), and Marine Institute.

Rivers play an important role in the overall transport of microplastic pollution (1 μm to 5 mm), with fluvial dynamics expected to influence biotic interactions, particularly for fish. So far, there have been few assessments of microplastics in freshwater salmonids. The prevalence (i.e. percentage occurrence) and burden (i.e. abundance per fish) of microplastics were assessed in the gastrointestinal tracts (GITs) and stomach contents (SCs) of 58 brown trout Salmo trutta Linnaeus, 1758 sampled at six sites along the River Slaney catchment in south-east Ireland. Sites were divided into two classifications (high and low exposure) based on proximity to microplastic pollution sources, comprising three sites each. Analysis of biological traits (e.g. fish length) and diet was performed on the same fish to determine possible factors explaining microplastic burden. Microplastics were found in 72% of fish having been recovered from 66% of GITs (1.88 ± 1.53 MPs fish⁻1) and 28% of SCs (1.31 ± 0.48 MPs fish⁻1). Fibres were the dominant particle type recovered from GITs (67%) and SCs (57%) followed by fragments. No difference in median microplastic burden was observed between fish collected in high and low exposure sites. Microplastic burden was unrelated to fish fork length, while microplastic size distribution (100 ≤ 350 μm, 350 μm to ≤ 5 mm) was unrelated to S. trutta age class estimates. Furthermore, microplastic burden was not explained by dietary intake. Though further research is necessary, this study showed the presence of microplastics in wild S. trutta collected from an Irish riverine system, which could have further implications for top-level consumers that feed on the species, including humans. Further analysis is required to determine possible trophic linkages for the species, with respect to microplastics, and to assess the suitability of S. trutta for monitoring microplastics in river systems. Image 1 • Microplastics were found in 72% of brown trout Salmo trutta Linnaeus, 1758 examined. • No difference in microplastic burden was found between high and low exposure sites. • Microplastic burden was not explained by biological traits or diet. • Further analysis is required to assess trophic links and suitability for monitoring. Microplastics were detected in riverine brown trout Salmo trutta Linnaeus, 1758, confirming the species are ingesting this widespread pollutant. Burdens were not explained by the level of microplastic exposure, biological traits or dietary intake. [ABSTRACT FROM AUTHOR]