cicluri

Cicluri is the Romanian term for cycles, referring to sequences of events, states, or processes that recur over time or follow a repeating pattern. The word is used across disciplines to describe periodic or quasi-periodic phenomena, from natural environments to human activities.

Etymology: The term derives from Latin cyclus, via Italian or French, ultimately from Greek kuklos meaning circle.

Types and examples: Natural cycles include circadian rhythms and the day–night cycle, the lunar cycle, and the seasonal cycle. In Earth systems, the hydrological cycle (water cycle), carbon cycle, and nitrogen cycle describe the movement of matter through air, water, soil, and living organisms. Ecological cycles encompass population fluctuations and predator–prey dynamics. Geological cycles include glacial–interglacial cycles.

Biological and social cycles: The menstrual cycle and other reproductive cycles occur in many organisms. Economic cycles, such as business cycles, reflect periodic expansions and contractions in economies. Cultural and technological cycles appear as patterns of reuse, innovation, and obsolescence.

Measurement and analysis: A cycle is typically described by its period (time between repeats), frequency (repeats per unit time), amplitude (magnitude of change), and phase (position within the cycle). Researchers use time-series analysis, Fourier analysis, and other methods to identify cycles and forecast future behavior.