Carbon-nitrogen-oxygen cycl

Carbon-nitrogen-oxygen cycle CNO fusion cycle in stars greater than 1 M(.) that produces odd-mass nuclei 13C, 150 and 15N. 

Once the sun has synthesized He and He, further nuclear reactions involving these nuclei may lead to the production of C, which then starts a carbon-nitrogen-oxygen cycle ... 

Under low-dose conditions, forest ecosystems act as sinks for atmospheric pollutants and in some instances as sources. As indicated in Chapter 7, the atmosphere, lithosphere, and oceans are involved in cycling carbon, nitrogen, oxygen, sulfur, and other elements through each subsystem with different time scales. Under low-dose conditions, forest and other biomass systems have been utilizing chemical compounds present in the atmosphere and releasing others to the atmosphere for thousands of years. Industrialization has increased the concentrations of NO2, SO2, and CO2 in the "clean background" atmosphere, and certain types of interactions with forest systems can be defined. 

Hamersley, M. R., and Howes, B. L. (2003). Contribution of denitrification to nitrogen, carbon, and oxygen cycling in tidal creek sediments ofa New England salt marsh. Mar. Ecol. Prog. Ser. 262, 55—69. 

Feedbacks Between the Nitrogen, Carbon and Oxygen Cycles... 

Evolutionary History of the Nitrogen, Carbon, and Oxygen Cycles 1537... 

Biological feedbacks to the global nitrogen, carbon, and oxygen cycles 1549... 

Biological feedbacks into the global nitrogen and oxygen cycles are intricately dependant on cfimate patterns and oceanic circulation which also influence trace metal availabifity in the upper ocean (Fig. 35.5). In this section we explore future scenarios in the oceanic nitrogen, carbon and oxygen cycles due to shifts in aeolian iron availabifity, variations in climate, and ocean circulation. 

Hydrogen burning occurs in two key reaction sequences, the PP (or proton-proton) chains and the CNO (Carbon-Nitrogen-Oxygen) bi-cycle. Both sequences were first understood by Hans Bethe and his collaborators in the 1930s, for which work Bethe won the Nobel Prize in 1967 (5). 

In more massive stars (> 1.3 times the mass of our sun), which have even higher internal temperatures (>l.7x 10 K), the carbon-nitrogen-oxygen (CNO) cycle can provide an alternative synthesis of He, as shown by Equations (2.29)-(2.34). The CNO cyck is catalytic for the production of He, as shown in Equation (2.35). This is the dominant source of energy in stars that are larger than our sun. A schematic diagram of the CNO cycle is shown in Figure 2.17 ... 

---