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Filtering by: Creator Dragila, Maria Remove constraint Creator: Dragila, Maria Resource Type Dissertation Remove constraint Resource Type: Dissertation

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  • Physical processes that control droplet transport in rock fracture systems

    Creator:
    Hay, Katrina M.
    Abstract:
    Aquifer recharge is generally driven by fluids that move from the Earth’s surface to groundwater through the unsaturated zone, also known as the vadose zone. When the vadose zone is fractured, fluids, which may include contaminants, can move through the fracture network as well as the porous matrix. Such a...
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    Dissertation
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    Control Droplet Transport in Rock Fracture Systems Abstract approved: Maria I. Dragila Aquifer recharge

  • Hydrological consequences of two native shrubs in semi-arid Senegal : patterns, processes, concepts and methods

    Creator:
    Kizito, Fred
    Abstract:
    Water availability is a critical limiting element in semi-arid ecosystem productivity and presents particular challenges in Sahelian countries such as Senegal. The landscapes are characterized by the presence of two common semi-arid shrubs (Piliostigma reticulatum and Guiera senegalensis), both of which may be important hydraulic regulators in these water-limited ecosystems....
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    Abstract approved: Redacted for Privacy Maria Ines Dragila Water availability is a critical limiting

  • Genesis of iron oxides in unsaturated porous media

    Creator:
    Grover, Deeksha
    Abstract:
    The kinetics of physical and chemical processes controlling the precipitation of iron oxide minerals in unsaturated media were investigated in this study. The characteristic morphology, mineralogy, and chemistry of iron oxides were also explored. Laboratory column experiments using fine and coarse grades of silica sand were conducted to compare the...
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    Dissertation
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    Iron Oxides in Unsaturated Porous Media Abstract approved: John E. Baham Maria I. Dragila The

  • Thermodynamics of non-dilute saline solutions in variably saturated porous media

    Creator:
    Burns, Erick R.
    Abstract:
    Non-dilute salt strength solutions occur in many near surface geologic environments. In order to better understand the occurrence and movement of the water and salt, mathematical models for this non-ideal fluid need to be developed. Initial boundary value problems may then be solved to predict behavior for comparison with observations....
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    Dissertation
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    research core of my committee is Professors John Selker, Maria Dragila, and Ron Guenther. Each has

  • Movement of zoospores of Phytophthora citricola in saturated porous media

    Creator:
    Ochiai, Naoyuki
    Abstract:
    The genus Phytophthora comprises numerous plant pathogens in both natural and managed ecosystems. For Phytophthora spp. that infect roots, dispersal occurs in soil water through a combination of advection and swimming of specialized motile propagules (zoospores). Specific biological and physico-chemical processes, however, remain poorly understood, due to difficulties in studying...
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    approved: Maria I. Dragila Jennifer L. Parke The genus Phytophthora comprises numerous plant

  • The Impact of Freeze-Thaw Cycles to the Physical and Biogeochemical Properties of Alaskan Permafrost Soils

    Creator:
    Rooney, Erin C.
    Abstract:
    Arctic warming is exposing thawing permafrost to repeated freeze-thaw, a disruptive process that can alter soil biogeochemistry and physical structure. To investigate the impact of permafrost exposure to freeze-thaw, soil response was tested across three scales: 2.5 cm³ aggregates, a forested hillslope, and two sites at contrasting latitudes. XCT imaging...
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    thank Kaizad Patel, Angela Possinger, Maria Dragila, Odeta Qafoku, and David Myrold for their guidance

  • Ecohydrological mediation of water budget partitioning and time scales of subsurface flow in a seasonally semi-arid grassland

    Creator:
    Pangle, Luke A.
    Abstract:
    Understanding how the interactions and feedbacks between plant function, climate, and soils ultimately affects the terrestrial water balance and subsurface flow processes is major challenge in scientific hydrology. This dissertation summarizes the findings of a manipulative climate warming experiment, an observational field study that utilized stable-isotope tracers, and associated modeling...
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    effectively. Thanks, Jillian. I thank my other committee members, Maria Dragila, Renee Brooks, and Jay

  • Mineral Surfaces as Agents of Environmental Proteolysis: Mechanisms and Controls

    Creator:
    Chacon, Stephany S.
    Abstract:
    The bottleneck in the turnover of soil organic matter (SOM) is the conversion of large molecular compounds into smaller compounds that can be transported through a cell membrane of a microbe for processing. Once inside the cell, organic compounds can be converted into biomass or be respired. The microbial depolymerization...
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    completing my work I’d like to thank my committee Dr. David Myrold, Dr. Peter Bottomley, Dr. Maria Dragila

  • The Biology and ecology of weeping alkaligrass (Puccinellia distans) and Nuttall’s alkaligrass (Puccinellia nuttalliana)

    Creator:
    Tarasoff, Catherine
    Abstract:
    Weeping alkaligrass (Puccinellia distans) and Nuttall’s alkaligrass (Puccinellia nuttalliana) infest Kentucky bluegrass seed fields of eastern Oregon. Weeping alkaligrass is an introduced species from Eurasia, whereas Nuttall’s alkaligrass is native to semi arid environments of western North America. These species are often referred to collectively as ‘alkaligrass’; however, for farmers...
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    summer weekends hiking the Wallowas. I would like to thank my graduate committee of Dr. Maria Dragila

  • Modeling Survival of Soilborne Phytophthora spp. and Characterizing Microbial Communities in Response to Soil Solarization and Biocontrol Amendment in Container Nursery Beds

    Creator:
    Funahashi, Fumiaki
    Abstract:
    In horticultural nurseries for container-grown plants, production and sales have been threatened by the presence of a quarantined plant pathogen, Phytophthora ramorum (causal agent of sudden oak death). Infested nursery beds are an important source of P. ramorum, which can initiate disease through movement with surface water to infect roots...
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    within my own interests and strengths. I extend this gratitude to my committee member, Maria Dragila