hydrogen cycle
111Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
112Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
113Earth — This article is about the planet. For other uses, see Earth (disambiguation). Earth   …
114Oxidative phosphorylation — The electron transport chain in the mitochondrion is the site of oxidative phosphorylation in eukaryotes. The NADH and succinate generated in the citric acid cycle are oxidized, releasing energy to power the ATP synthase. Oxidative… …
115Nuclear fusion — Nuclear physics Radioactive decay Nuclear fission Nuclear fusion Classical dec …
116Grid energy storage — is used to manage the flow of electrical energy. For large scale load levelling on an interconnected electrical system, electric energy producers send low value off peak excess electricity over the electricity transmission grid to temporary… …
117Battery (electricity) — For other uses, see Battery (disambiguation). Various cells and batteries (top left to bottom right): two AA, one D, one handheld ham radio battery, two 9 volt (PP3), two AAA, one C, one …
118Hypothetical types of biochemistry — are forms of biochemistry speculated to be scientifically viable but not proven to exist at this time. While the kinds of living beings we know on earth commonly use carbon for basic structural and metabolic functions, water as a solvent and DNA… …
119Alternative biochemistry — is the speculative biochemistry of alien life forms that differ radically from those on Earth. It includes biochemistries that use elements other than carbon to construct primary cellular structures and/or use solvents besides water. Theories… …
120Stellar evolution — Life cycle of a Sun like star Stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. Depending on the mass of the star, this lifetime ranges from only a few million years (for the most… …
