This paper studies the vectors of cofactors in a screw matrix assembled by n screws and investigates the properties and different arrangements of cofactors. An augmentation screw which is linearly independent of n screws in the screw matrix is proposed and is used to relate the vector of cofactors to a reciprocal screw and subsequently to the reciprocal screw system. The paper proposes a new al...

While reviewing molecules corresponding to reciprocal graphs (graphs with all reciprocal eigenvalue pairs), new examples of reciprocal graphs are presented. Essential features of cross-conjugation are delineated, and how this phenomenon is important in the design of conducting and ferromagnetic polymers is discussed. Some recursion equations for determining characteristic polynomials of comb an...