Semigroups, algebraic structures defined by a set equipped with an associative binary operation, are a cornerstone within modern algebra. Their study encompasses both abstract theoretical development ...

THE first edition of this book was reviewed at some length in the issue of NATURE for March 18, 1909 (vol. lxxx., p. 64). The additions made to the present edition are incorporated in an appendix of ...

The human ecosystem is made of open and closed systems. While the earth is a closed system for matter but an open system for energy, the human body is considered an open system. There is a growing ...

String theory began over 50 years ago as a way to understand the strong nuclear force. Since then, it’s grown to become a theory of everything, capable of explaining the nature of every particle, ...