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.
Results
Showing 1 to 20 of 22 for “"marine biogeochemistry"”.
-
The marine biogeochemistry of molybdenum
… Laboratory culture work on two Nz fixing marine cyanobacteria, Trichodesmium and Crocosphaera, and a marine facultative denitrifier, Marinobacter hydrocarbanoclasticus, showed that Mo cell quotas in these organisms were positively correlated with Mo-containing enzyme activity. Mo …
-
The marine biogeochemistry of molybdenum
… Laboratory culture work on two N2 fixing marine cyanobacteria, Trichodesmium and Crocosphaera, and a marine facultative denitrifier, Marinobacter hydrocarbanoclasticus, showed that Mo cell quotas in these organisms were positively correlated with Mo-containing enzyme activity. Mo …
-
The marine biogeochemistry of chromium isotopes
In the ocean, chromium (Cr) is a redox-sensitive trace metal. The reduction of Cr(VI) to Cr(III) occurs in oxygen deficient zones (ODZs), and Cr reduction in general has been identified as a significant Cr isotope fractionation mechanism. This thesis presents the first Cr isotope variations (d53Cr) …
-
The marine biogeochemistry of zinc isotopes
… hydrothermal fluids and minerals, cultured marine phytoplankton, natural plankton, and seawater. By measuring Zn isotopes in a diverse array of marine samples, we hope to understand how Zn isotopes are fractionated in the oceans and how Zn isotopes may be used as tracers of marine …
-
The marine biogeochemistry of zinc isotopes
… hydrothermal fluids and minerals, cultured marine phytoplankton, natural plankton, and seawater. By measuring Zn isotopes in a diverse array of marine samples, we hope to understand how Zn isotopes are fractionated in the oceans and how Zn isotopes may be used as tracers of marine …
-
The marine biogeochemistry of chromium isotopes
In the ocean, chromium (Cr) is a redox-sensitive trace metal. The reduction of Cr(VI) to Cr(III) occurs in oxygen deficient zones (ODZs), and Cr reduction in general has been identified as a significant Cr isotope fractionation mechanism. This thesis presents the first Cr isotope variations (653 …
-
The marine biogeochemistry of dissolved and colloidal Iron
… iron (dFe) has extremely low concentrations in marine waters that can drive phytoplankton to Fe limitation, effectively linking the Fe and carbon cycles. Understanding the marine biogeochemical cycling and composition of dFe was the focus of this thesis, with an emphasis on the role of the size …
-
The marine biogeochemistry of dissolved and colloidal iron
… iron (dFe) has extremely low concentrations in marine waters that can drive phytoplankton to Fe limitation, effectively linking the Fe and carbon cycles. Understanding the marine biogeochemical cycling and composition of dFe was the focus of this thesis, with an emphasis on the role of the size …
-
Marine Biogeochemistry Studies of Iron and Hydrogen Peroxide using Flow Injection-Chemiluminescence
… level and their application to investigate marine processes. Two flow injection methods, one based on direct sample injection and another involving the preconcentration of iron, were used to determine iron(II) and dissolved iron and assess potential interference from a number of metals and …
-
The marine biogeochemistry of dissolved organic carbon and dissolved organic nutrients in the Atlantic Ocean
The marine biogeochemistry of dissolved organic carbon (DOC) has come under<br/>increased scrutiny because of its involvement in the global carbon cycle and<br/>consequently climate change. Dissolved organic nitrogen (DON) and phosphorus<br/>(DOP), which have historically been ignored because of …
-
A modeling study of the marine biogeochemistry, plankton dynamics, and carbon cycle on the continental shelf off the West Antarctic Peninsula
… this region, an ocean circulation, sea ice and biogeochemistry model was implemented to help fill the gaps in the dataset. The results with the present best case from the suite of sensitivity experiments indicate that the model is able to represent the seasonal and interannual variations …
-
A modeling study of the marine biogeochemistry, plankton dynamics, and carbon cycle on the continental shelf off the West Antarctic Peninsula
… this region, an ocean circulation, sea ice and biogeochemistry model was implemented to help fill the gaps in the dataset. The results with the present best case from the suite of sensitivity experiments indicate that the model is able to represent the seasonal and interannual variations …
-
Decoding divergence in marine protistan communities: from strain diversity to basin biogeography
… is needed to predict the impact of protists on marine biogeochemistry and protists’ environmental change sensitivity. I cultured twelve strains of the coccolithophore Gephyrocapsa huxleyi across temperatures, which revealed strain-specific differences in thermal optima and niche widths. I used …
-
Bacterial Assemblages And Microbial Enzyme Activity In The Major Tributaries Of The Lower Mississippi River
… connections between terrestrial land use and marine biogeochemistry and act as conduits for organisms and allochthonous nutrients. Bacteria dominate carbon cycling and nutrient processing in rivers, and therefore can influence regional and global elemental cycles. This study characterized the …
-
Decoding divergence in marine protistan communities: from strain diversity to basin biogeography
… is needed to predict the impact of protists on marine biogeochemistry and protists’ environmental change sensitivity. I cultured twelve strains of the coccolithophore Gephyrocapsa huxleyi across temperatures, which revealed strain-specific differences in thermal optima and niche widths. I used …
-
Insights into vitamin B12 production, acquisition, and use by marine microbes
The distribution and magnitude of marine primary production helps determine the ocean's role in global carbon cycling. Constraining factors that impact this productivity and elucidating selective pressures that drive the composition of marine microbial communities are thus essential aspects of …
-
Dynamics of phytoplankton community composition in the western Gulf of Maine
… of phytoplankton community composition to marine biogeochemistry and ecosystem processes and motivated by the need to understand their distributions on regional to global scales. The ultimate goal was to predict surface phytoplankton communities using satellite remote sensing by relating …
-
Insights into vitamin B₁₂ production, acquisition, and use by marine microbes
The distribution and magnitude of marine primary production helps determine the ocean's role in global carbon cycling. Constraining factors that impact this productivity and elucidating selective pressures that drive the composition of marine microbial communities are thus essential aspects of …
-
Microfluidics for bacterial chemotaxis
… disease pathogenesis, in-situ bioremediation and marine biogeochemistry. And therefore, studying bacterial chemotaxis is of significant importance to scientists and engineers alike. Microfluidics has revolutionized the way we study the motile behavior of cells by enabling observations at high …
-
Accumulation of Platinum Group Elements by the Marine Microalga, Chlorella stigmatophora
Very little information exists on the marine biogeochemistry of Rh, Pd and Pt, or the platinum group elements (PGE), an emerging group of contaminants whose principal emissions are associated with the abrasion of the catalytic converter in motor vehicles and chemotherapy drugs discharged in …
Page 1 of 2