dynamic analysis and study of atomic force microscope in liquid environment is the main goal of this research. hydrodynamic and squeeze forces act on cantilever of atomic force microscope which works in liquid environment, so. in this paper the effect of different environmental and physical factors had studied on frequency response diagrams. the importance of frequency response analysis is stud...

Amplitude and phase variability are commonly found in many different types of pulsating stars. This suggests a common, presently unknown physical origin. We have examined the phenomenon in several δ Scuti stars with extensive data and find the beating of close frequencies to be responsible. This is demonstrated for the star FG Vir by testing the relationship between the observed amplitude and p...