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You searched for +publisher:"Oregon State University" +contributor:("Reimers, Clare E."). Showing records 1 – 2 of 2 total matches.

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Oregon State University

1. McCann-Grosvenor, Kristina. Eddy correlation benthic O₂ exchange rates and characterizations of sediment properties from the central Oregon shelf at 30 meters.

Degree: MS, Oceanography, 2011, Oregon State University

Rates of benthic O₂ exchange are important measurements for determining organic matter remineralization, and can shed light on factors driving biogeochemical processes in coastal environments. Measurement of in situ O₂ consumption and production within permeable sediments, such as those found over ~43% of the Oregon-Washington shelf, has traditionally been done using methods that underestimate the flux for environments affected by waves. Modified from atmospheric research, the non-invasive eddy correlation technique can measure O₂ flux across the sediment-water interface without disturbing the natural hydrodynamic flow. In 2009, eddy correlation measurements were made at discrete times over a 7-month period at a 30 m site off Yaquina Head, Newport, OR. The results of this newly developed method are evaluated here, together with properties of sediment cores taken at the study site. O₂ flux was found to be primarily into the bed (-6.2 to -30.7 mmol m⁻² d⁻¹) and was enhanced during periods of higher bottom water O2 concentration. Contributions to O₂ flux were seen in eddy correlation cospectra at surface wave frequencies and dependent on wave height. The sediments were fine sands with permeabilities of 1.3-4.7 x 10⁻¹¹ m². Sediment pigment and organic carbon concentrations were low (chlorophyll-α : 0.03-0.45 μg g⁻¹, phaeophytin-α: 0.6-1.4 μg g-1 and organic carbon: 0.07-0.11 wt %), indicating high rates of organic matter export and/or remineralization. From these results it is inferred that physical forcing and changes in bottom water properties affect the inner shelf sedimentary environment more than seasonal cycles in primary production. Advisors/Committee Members: Reimers, Clare E. (advisor), Ozkan-Haller, Tuba (committee member).

Subjects/Keywords: oxygen exchange

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

McCann-Grosvenor, K. (2011). Eddy correlation benthic O₂ exchange rates and characterizations of sediment properties from the central Oregon shelf at 30 meters. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/19918

Chicago Manual of Style (16th Edition):

McCann-Grosvenor, Kristina. “Eddy correlation benthic O₂ exchange rates and characterizations of sediment properties from the central Oregon shelf at 30 meters.” 2011. Masters Thesis, Oregon State University. Accessed May 08, 2021. http://hdl.handle.net/1957/19918.

MLA Handbook (7th Edition):

McCann-Grosvenor, Kristina. “Eddy correlation benthic O₂ exchange rates and characterizations of sediment properties from the central Oregon shelf at 30 meters.” 2011. Web. 08 May 2021.

Vancouver:

McCann-Grosvenor K. Eddy correlation benthic O₂ exchange rates and characterizations of sediment properties from the central Oregon shelf at 30 meters. [Internet] [Masters thesis]. Oregon State University; 2011. [cited 2021 May 08]. Available from: http://hdl.handle.net/1957/19918.

Council of Science Editors:

McCann-Grosvenor K. Eddy correlation benthic O₂ exchange rates and characterizations of sediment properties from the central Oregon shelf at 30 meters. [Masters Thesis]. Oregon State University; 2011. Available from: http://hdl.handle.net/1957/19918


Oregon State University

2. Ryckelynck, Natacha. Understanding the anodic mechanism of a seafloor fuel cell.

Degree: MS, Oceanography, 2004, Oregon State University

Anoxic sediment overlain by oxic seawater establishes a voltage gradient on the order of 0.7-0.8V across the sediment-water interface. This study follows Reimers et al. (2001) and Tender et al. (2002) who reported the development of a seafloor fuel cell to harvest electrical energy from this potential difference. Prototype fuel cells were deployed for demonstration purposes in the Yaquina Bay estuary, Newport (Oregon, USA) and in a salt marsh near Tuckerton (New Jersey, USA) and were monitored during approximately seven months at either fixed current or fixed potential. Control cells with electrodes not connected to each other (open circuit) were deployed at each site near the prototype devices. The impacts of fuel cell processes on sediment solids and porewaters were studied by taking cores of sediment down to the surface of the anode (electrode embedded in sediment) of both active and control cells. Porewater profiles showed significant increases in sulfate and iron concentrations, but also sulfide depletion approaching the active anode. Solid-phase acid volatile sulfide and pyrite decreased significantly toward the anode. Fe(III) mineral phases did not appear affected by the presence of the fuel cell. Particulate organic carbon was not depleted significantly either. Electron microprobe analyses and SEM images revealed accumulations of sulfur and iron with Fe/S ratios <1 at the electrode surface of the fuel cell anode. Sulfur deposition was also observed on electrodes simulating a marine fuel cell, under sterile conditions, using US- as sole electron acceptor. Moreover current densities and voltages displayed at both anodes and cathodes in these laboratory experiments were similar to the values measured with the fuel cell devices in the field. Collectively these results indicate that electron transfer processes at the anodes of seafloor fuel cells result in the oxidation of dissolved and solid-phase forms of reduced sulfur in sediments producing mainly S⁰ which deposits at the electrode surface. This oxidation product enhances a localized biogeochemical cycle involving biofilm bacteria that may regenerate sulfate and sulfide. This mechanism may sustain electron transfer processes or co-occur while other biofilm bacteria use the anode directly as a terminal electron acceptor. Advisors/Committee Members: Reimers, Clare E. (advisor), Fisk, Mark (committee member).

Subjects/Keywords: Electric power production from chemical action

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ryckelynck, N. (2004). Understanding the anodic mechanism of a seafloor fuel cell. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/22962

Chicago Manual of Style (16th Edition):

Ryckelynck, Natacha. “Understanding the anodic mechanism of a seafloor fuel cell.” 2004. Masters Thesis, Oregon State University. Accessed May 08, 2021. http://hdl.handle.net/1957/22962.

MLA Handbook (7th Edition):

Ryckelynck, Natacha. “Understanding the anodic mechanism of a seafloor fuel cell.” 2004. Web. 08 May 2021.

Vancouver:

Ryckelynck N. Understanding the anodic mechanism of a seafloor fuel cell. [Internet] [Masters thesis]. Oregon State University; 2004. [cited 2021 May 08]. Available from: http://hdl.handle.net/1957/22962.

Council of Science Editors:

Ryckelynck N. Understanding the anodic mechanism of a seafloor fuel cell. [Masters Thesis]. Oregon State University; 2004. Available from: http://hdl.handle.net/1957/22962

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