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Physical Sciences and Mathematics Commons

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Purdue University

Open Access Dissertations

2014

Earth Sciences

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

A New Passive Surface Water Flux Meter For Simultaneous Measurement Of Contaminant And Water Fluxes In Streams And Rivers, Stephen A. Sassman Oct 2014

A New Passive Surface Water Flux Meter For Simultaneous Measurement Of Contaminant And Water Fluxes In Streams And Rivers, Stephen A. Sassman

Open Access Dissertations

A passive surface water flux meter (PSFM) for measurement of contaminant concentration/flux in rivers and streams is described and tested. The novel PSFM design was developed for portability and ease of adaptability for a variety of contaminant classes. Although previous designs have been evaluated under constant flow conditions, the PSFM has never been used for measurement of pesticides or hormones and this is the first time that it has been tested under transient flow. Discharge through the PSFM is assessed by measuring miscible displacement of alcohol tracers from granular activated carbon (GAC). The tracer retardation factors (R) measured by miscible …


Particle Swarms In Confining Geometries, Eric Robert Boomsma Oct 2014

Particle Swarms In Confining Geometries, Eric Robert Boomsma

Open Access Dissertations

The transport of micro- and nano-particles in subsurface fluid deposits is an area of increasing interest due to the rising use of these particles for consumer and industrial purposes. Subsurface particle transport is complicated by the presence of fractures and fracture networks which govern the paths that particles will be able to take. In this thesis, subsurface particle transport will be investigated using particle swarms; collections of hydro-dynamically interacting particles which exhibit group behavior. The effects of fluid viscosity, particle properties, fracture geometry, and fracture aperture on swarm behavior were experimentally investigated. ^ Swarm parameters were examined in time with …


Soil Quality And Nitrogen Cycling Dynamics Altered By Fertility Amendments In Intensively Managed Vegetable Production Systems, Matt A. Rudisill Oct 2014

Soil Quality And Nitrogen Cycling Dynamics Altered By Fertility Amendments In Intensively Managed Vegetable Production Systems, Matt A. Rudisill

Open Access Dissertations

Fresh market vegetable production in the Midwest U.S. is growing rapidly as a result of increased demand for locally-sourced food. High tunnels are becoming increasingly popular among Midwest vegetable growers as these structures offer many production benefits including season extension. However, vegetables require substantial fertility inputs, particularly nitrogen (N), in order to meet desired levels of productivity, and some fertility management strategies can negatively impact soil and environmental quality. This can be particularly problematic in high tunnels, where longer production periods and modification of the growing environment put these systems at greater risk for soil degradation. Identification of fertility practices …