the effect that the material in a surface has on the frictional force created by the application of a force to the surface: S = f Ã N, where S = friction, f = friction coefficient, N = reaction to the vertical application of a given force. In a normal joint the f value is very small (0.008).
Alluring, you have a unique inner potential. With your first breath, a spiritual essence and purpose became a part of you, gave you life, and activated your physical growth. Your particular date of birth determines your unique core purpose, the reason for your life, and the pathway you should follow for ultimate happiness.
Hans Spemann (1869 - 1941) Gastrulation means the formation of gut (Greek, gastrula = belly), but has now a more broad sense to to describe the formation of the trilaminar embryo. The epiblast layer, consisting of totipotential cells, derives all 3 embryo layers: endoderm, mesoderm and ectoderm. The primitive streak is the visible feature which represents the site of cell migration to form the additional layers.