Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"Sampling Devices"”.
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Paper Spray - Mass Spectrometry: Investigation of Sampling Devices for Illicit Drug Detection and Quantification
… samples at trace levels. In this work, different sampling devices for PS-MS were investigated to improve the assay’s simplicity and sensitivity over traditional approaches. In particular, chapter two characterizes an alternate paper substrate to enhance drug detection on surfaces like asphalt, …
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Field comparison of groundwater sampling methods
Most ground-water sampling methods require the investigator to purge a large quantity of stagnant water from a well prior to collecting a sample. The use of in situ ground-water sampling devices which minimize or eliminate the need for purging would help to alleviate these problems. In this field …
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Time domain metrology for dielectric spectroscopy of particulates
… were investigated and three different types of sampling devices were examined. The investigation examined the positive and negative aspects of three different types of sample holders to determine a method of obtaining dielectric information from in-situ time domain measurements. A scheme using a …
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Movement and Structure of Atmospheric Populations of Fusarium
… in colony counts. To test this hypothesis, sampling devices on UAVs were separated into two groups, four inner sampling devices opened during the first 10 minutes and four outer sampling devices opened during the second 10 minutes. Results indicated that (1) consecutive collections of …
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Characterization of a 3D printed pumped counterflow virtual impactor and an aerodynamic lens concentrator
… of atmospheric aerosols. Two pre-existing cloud sampling devices, the pumped counterflow virtual impactor (PCVI) and aerodynamic lens concentrator (ADL), were modelled using computer aided design software and printed using stereolithography printing. These devices were compared against their …
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Determination of Size Fractions and Concentrations of Airborne Particulate Matter Generated From Construction and Demolition Waste Processing Facilities
… facilities. Active stationary particulate sampling devices were employed to quantify the particle sizes of interest. Results were compared to United States Environmental Protection Agency (EPA) National Ambient Air Quality Standards(NAAQS) and United States Occupational Safety and Health …
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A method for using polyethylene passive samplers to measure polycyclic aromatic hydrocarbon chemical activity in sediments
… 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 used to …
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Survey of Storm Water Quality in an Urban Environment
… landscapes, i.e. nutrients, metals, solids, etc. Sampling devices were constructed and implemented in selected basins around Youngstown State campus. Storm water quality sampling was performed to establish a baseline for storm water contaminant loading around Youngstown State University. Water …
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Development of an Autonomous Unmanned Aerial Vehicle for Aerobiological Sampling
… aerial vehicle (UAV) platform for aerobiological sampling tens to hundreds of meters above agricultural fields. Autonomous UAVs have the potential to extend the range of aerobiological sampling, improve positional accuracy of sampling paths, and enable coordinated flight with multiple aircraft at …
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Patterns of microbial community development in isolated aquatic systems
… foam (PF) artificial substrates were used as sampling devices in these systems. Distance from another aquatic system was found to have a significant effect colonization in these systems. Exclusion of macroscopic organisms, however, did not strongly affect the process of microbial community …
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Investigations of freshwater surface microlayers: comparisons of methods for sampling various microlayer thicknesses with observations on select chemical and microbiological features of microlayers of three aquatic ecosystems relative to the bulk of subsurface water
… the comparison of four surface microlayer sampling devices. The objective of this comparison was to determine the relative sampling efficiencies, and depth of water collected by each sampler. The results showed that the plate and drum samplers were far superior to the screen and tray …
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Amphibian occupancy and effects of habitat use on pesticide exposure in Iowa agricultural wetlands
… and assessed their survival. We used Passive Sampling Devices (PSDs) to test for differences in pesticide exposure among grassland, wetland, and agricultural habitats.</p> <p>We found that pesticide concentration analyzed from PSDs varied among habitat types (P < 0.01) with concentration …
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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
… 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 between …
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Combined effects of bioavailable organic contaminants in the aquatic environment.
In contrast to conventional spot or bottle water sampling techniques, passive sampling has been shown to be a reliable and efficient method for monitoring the toxicologically-relevant, freely-dissolved (e.g. bioavaialable) concentrations of a wide range of organic contaminants in water. At the same …
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Estimating Chronic Exposure to Steroid Hormones in Water
… risk. So, the continued advancement of sampling methodology is essential to better understanding chemical exposure. While traditional sampling methodologies, including grab sampling, only capture a snapshot of exposure, the development of passive sampling devices (PSDs) has allowed for …
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Efficacy of the Microtally® Mitt for sampling of beef carcasses
… pathogenically contaminated products. Several sampling methods, including N60 excision, N60 Plus™, and continuous and manual sampling devices using the Microtally® Swab or Mitt, are widely used in industry for verification testing. Among these, the Microtally® Mitt (MT-Mitt) is a sterile cloth …
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Monitoring of atmospheric polycyclic aromatic hydrocarbons through optimization of analytical techniques
… indoors, as well as in working environments. Sampling, extraction, sample clean up and analysis constitute the principal stages required for the determination of airborne PAHs. Most conventional methods utilize high volume samplers and high volume extraction methods for the analysis of …