(physics) A thermodynamic cycle used as an ideal standard for the comparative performance of heat engines.

Alternative spelling of sulfur cycle

(chemistry, biochemistry) the natural cycle which includes the mineralization of organic sulfur to sulfide, oxidation of this to sulfate, and reduction of this to sulfide followed by microbial incorporation of this into organic compounds

The recurring cycle of physiological changes in the uninseminated females of some animal species that is associated with reproductive fertility; especially the cycle in a human woman.

plural of CNO cycle

The natural cycle of evaporation of water from the oceans etc, and subsequent condensation and precipitation as rain and snow

(biology) A form of viral reproduction involving the fusion of the nucleic acid of a bacteriophage with that of a host, followed by proliferation of the resulting prophage

(biology) The normal process of viral reproduction involving penetration of the cell membrane, nucleic acid synthesis and lysis of the host cell

Alternative form of vicious circle

(biochemistry) A series of metabolic reactions by which many different organisms utilise fats for the synthesis of carbohydrates