Seep-carbonate lamination controlled by cyclic particle flux

Seep-carbonate lamination controlled by cyclic particle flux

Authigenic carbonate build-ups develop at seafloor methane-seeps, where microbially mediated sulphate-dependent anaerobic oxidation of methane facilitates carbonate precipitation. Despite being valuable recorders of past methane seepage events, their role as archives of atmospheric processes has not been examined. Here we show that cyclic sedimentation pulses related to the Indian monsoon in co...

U–Th stratigraphy of a cold seep carbonate crust

On continental margins, oxidation of methane-rich fluids from the sediment often leads to formation of authigenic carbonate pavements on the seafloor. The biogeochemical processes involved during this carbonate precipitation are increasingly understood, but little is known about the duration or mode of carbonate crust formation. Here, we report uranium and thorium concentrations and isotope com...

Free radical polymerization study of glycerin carbonate methacrylate for the synthesis of cyclic carbonate functionalized polymers

Th fractionation by ocean transport , biogenic particle flux and particle type

Pa and Th are removed from the water column by a process of reversible scavenging which quickly removes Th to the sediment. Pa is less efficiently scavenged onto particles than Th and is therefore more effectively transported via advection and diffusion before it reaches the ocean sediment. This study combines particle fields (dust, opal, CaCO3, POC) derived from observations with the Bern3D in...

Lipase-Mediated Syntheses of Trimethylolpropane-Based Biolubricant and Cyclic Carbonate

Biocatalysis is considered as benign and efficient alternative to chemical catalysis for organic syntheses. Lipases are the most versatile biological catalysts implemented so far with great potential for production of different chemicals and materials in nonconventional reaction media. This thesis presents investigations on lipase catalyzed esterification and transesterification reactions in so...