Global ETD Search
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Showing 1 to 20 of 24 for “"Passive Samplers"”.
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Can polyethylene passive samplers be used to measure infiltration?
… including groundwater seepage. Polyethylene passive samplers have been used extensively to measure a chemical's concentration in the sediment or water column and conventional seepage meters are deployed to infer the infiltration flux. A model was developed to describe how passive samplers …
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Using passive samplers to assess bioavailability, toxicity, and reactivity of hydrophobic organic chemicals (HOCs)
… three applications of polyethylene (PE) passive sampling, which enhance our toolbox for estimating environmental hazards associated with HOCs. First, we present a methodology that can be used to estimate the bioaccumulation potential of numerous organic chemicals based on passive sampling …
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Using passive samplers to assess bioavailability, toxicity, and reactivity of hydrophobic organic chemicals (HOCs)
… three applications of polyethylene (PE) passive sampling, which enhance our toolbox for estimating environmental hazards associated with HOCs. First, we present a methodology that can be used to estimate the bioaccumulation potential of numerous organic chemicals based on passive sampling …
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Investigation of polyethlyene passive samplers' efficacy in deducing sediment pore water concentrations of PCBs
… measurement of pore water concentrations. PE passive samplers are an inexpensive, fast alternative to liquid-liquid extraction of pore waters and sediment extraction with equilibrium partitioning. To demonstrate the potential of PE passive samplers to measure sediment pore water …
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A method for using polyethylene passive samplers to measure polycyclic aromatic hydrocarbon chemical activity in sediments
… for the use of polyethylene (PE) sheets as passive sampling devices for measuring chemical activities was explored. A model which depends on a concentration gradient and two mass transfer limiting zones in series was used. Internal tracer chemicals within the polyethylene devices (PEDs) were …
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Demonstrating the feasibility of polyethylene passive samplers for quantitative assessment of volatile organic compounds in soil
… by the successful use of polyethylene (PE) passive samplers in sediments, this research focused on demonstrating the feasibility of PE samplers to accurately assess volatile organic compounds in soil vapors. Experimental values of PE-water partitioning coefficients (Kpew) for benzene, …
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Assessment of sources of uncertainty in passive samplers of ambient air quality : evaluation Lakeland Industry and Community Association airshed 2009-2011
Passive samplers are subject to a myriad of sources of uncertainty, which affect their precision and accuracy. To investigate this uncertainty, an evaluation of passive sampler data for SO2, NO2, O3, and H2S was carried out in the Lakeland Industry & Community Association in east-central Alberta …
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Application of diffusive gradient in thin-film passive samplers to assess mercury availability and mobility in a fresh water river system
… of sediment, transportation, and processing. Passive sampling is an alternative technique that measures sediment porewater concentrations in-situ and without significant sample disturbance. One passive sampling technique for mercury in sediment porewater is Diffusive Gradient in Thin-Films …
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Polyethylene passive samplers for measuring hydrophobic organic chemical concentrations in sediment porewaters and their use in predicting bioaccumulation in soft-shell clams (Mya arenaria) from sites near Boston, MA
… (1) the use of polyethylene (PE) sheets as passive sampling devices in sediments, using performance reference compounds (PRCs) in order to reduce deployment times to the order of days, (2) the use of limited PRC data to calibrate mass-transfer models for the exchange of a suite of compounds …
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Occurrence and fate of endocrine disrupting chemicals and other hydrophobic organic compounds in a tropical river in Kenya
This thesis explores the application of passive sampling as a novel monitoring technique capable of quantifying aquatic pollutants at low environmental concentrations, and in a form that is directly applicable to risk assessment. Two passive samplers, namely polyethersulfone (PES) and silicone …
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Investigation Of The Use And Application Of Passive Sampling Methods For Understanding Potential Sources Of Mercury To Western United States
… sea level up to ~2800 m. Surrogate surfaces and passive samplers were deployed across nine locations at Point Reyes National Seashore, CA; Chalk Mountain, CA; Elkhorn Slough, CA; Chews Ridge, CA; Lick Observatory, CA; Yosemite National Park, CA; Hetch Hetchy Reservior, CA; Sequoia National Park, …
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The science behind Tenax extractable concentrations and their use in evaluating environmental risk
… by organic carbon alone. Desorption-based samplers, such as single-point Tenax extractions (SPTE), provide a clearer estimate of bioaccessibility than organic carbon normalization by serving as a sink for desorbing compound for the length of the extraction. In this way, SPTEs account for …
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Evaluating the combined use of three-dimensional hydrodynamic modeling and polyethylene passive sampling in the Lower Duwamish Waterway
Polyethylene (PE) passive samplers are capable of measuring in-situ, freely dissolved, time-averaged concentration distributions of contaminants in air, surface water, and sediment bed porewater. This sampling technique can be coupled with a three dimensional (3D) hydrodynamic model of a given …
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Air pollution impacts to agricultural crops
… O3 concentration in Peshawar, measured using passive samplers, was between 25-30ppb in February and March, but increased to 35-55ppb in April and May; it fell to 15-20ppb in November/December. O3 injury was found on potato (black flecking), onion (leaf tipburn) and cotton (white stipples) in a …
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A statistical investigation of ozone exposure assessment by direct and indirect measurement
… to human subjects was monitored using Harvard passive samplers during August and September of 1997. Each subject logged their location and activity during the exposure period. A three-dimensional kriging model of ozone was developed to estimate the ozone exposure for each subject from ambient …
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Quantifying Solute and Water Fluxes in Headwater Streams Using Passive Flux Meters
Passive samplers can be used to determine time-integrated patterns of water chemistry at one or many locations throughout a stream network while minimizing cost and sampling time. A passive flux meter (PFM) simultaneously estimates time-averaged water and solute mass fluxes in flowing water. PFMs …
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Monitoring and regulating cyanobacterial metabolites (microcystins and geosmin) in aquatic systems.
… the application of silicone rubber membranes as passive samplers was explored in spiked and environmental samples, demonstrating that silicone rubber membranes can successfully be used in environmental applications to deliver rapid and accurate determinations of both 2-methylisoborneol and …
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Water quality studies in Kranji Catchment, Singapore : use of organic tracer and PEDs for identifying potential sewage sources
… Asia. Polyethylene devices (PEDs) were used as passive samplers to measure NPEOs in stormwater drains in Kranji catchment. Fieldwork was conducted in the month of January 2010. PEDs were deployed in different land use areas in order to obtain an overview of concentration ranges across the Kranji …
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Personal exposure of children to formaldehyde in Perth, Western Australia
… Western Australia. Each child wore a personal passive formaldehyde sampler over a 24 hour period on two separate occasions, winter and summer. Samplers were also located indoors at home, outdoors at centralised locations and indoors at school for the corresponding period. A questionnaire about …
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The Influence of Agricultural Chemicals on Aquatic Invertebrate Biodiversity and Genetic Diversity in Northern Prairie Wetlands
… active (Gerking sampler, core) and two were passive samplers (activity trap, artificial substrate). The sampling gears were rated based on the number and diversity of invertebrates captured. The Gerking sampler captured significantly (t c 4.5, P = 0.02) more invertebrates than the other three …
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