Search results
Results from the WOW.Com Content Network
Crude oil, a transformed biogenic substance Natural gum, a secretion from Hevea brasiliensis. A biogenic substance is a product made by or of life forms. While the term originally was specific to metabolite compounds that had toxic effects on other organisms, [1] it has developed to encompass any constituents, secretions, and metabolites of plants or animals. [2]
Marine biogenic calcification is the production of calcium carbonate by organisms in the global ocean.. Marine biogenic calcification is the biologically mediated process by which marine organisms produce and deposit calcium carbonate minerals to form skeletal structures or hard tissues.
Conversely, increased damming has led to a reduction in silica supply to the ocean due to uptake by freshwater diatoms behind dams. The dominance of non-siliceous phytoplankton due to anthropogenic nitrogen and phosphorus loading and enhanced silica dissolution in warmer waters has the potential to limit silicon ocean sediment export in the ...
A few examples of the major greenhouse gases are water, carbon dioxide, methane, nitrous oxide, ozone, and CFCs. These gases can absorb infrared radiation from the Earth's surface as it passes through the atmosphere. The most influential greenhouse gas is water vapor. It frequently occurs in high concentrations, may transition to and from an ...
And also, after the gasification process, CO 2 takes up to 13% - 15.3% by mass in the syngas stream for biomass sources, while it is only 1.7% - 4.4% for coal. [29] This limit the conversion of CO to CO 2 in the water gas shift, and the production rate for H 2 will decrease accordingly.
They are unique among phytoplankton, because they require Si in the form of silicic acid (Si(OH)4) for growth and production of their frustules, which are made of biogenic silica (bSiO2) and act as ballast. [105] [107] According to the reports of Miklasz and Denny, [108] the sinking velocities of diatoms can range from 0.4 to 35 m/day.
When the nutrient rich deep ocean water is moved to the surface, algae bloom occurs, resulting in a decrease in carbon dioxide due to carbon intake from phytoplankton and other photosynthetic eukaryotic organisms. The transfer of heat between the layers will also cause seawater from the mixed layer to sink and absorb more carbon dioxide.
Here, the water is chilled by Arctic temperatures. It also gets saltier because when sea ice forms, the salt does not freeze and is left behind in the surrounding water. The cold water is now more dense, due to the added salts, and sinks toward the ocean bottom. Surface water moves in to replace the sinking water, thus creating a current.