Let $R$ be a prime ring with its Utumi ring of quotients $U$,  $C=Z(U)$ the extended centroid of $R$, $L$ a non-central Lie ideal of $R$ and $0neq a in R$. If $R$ admits a generalized derivation $F$ such that $a(F(u^2)pm F(u)^{2})=0$ for all $u in L$, then one of the following holds: begin{enumerate} item there exists $b in U$ such that $F(x)=bx$ for all $x in R$, with $ab=0$; item $F(x)=...

In this paper octagon shape planar microstrip antenna is presented. Octagonal antenna can find applications in Radar and Space-crafts. The antenna is fed by a 50 Ω microstrip line and printed on a dielectric Fr4 substrate of dimension (22mm X 22 mm) permittivity εr =4.4 and height h = 1.6 mm. The optimization on the planar octagonal microstrip has been done to accomplish an -10 dB return loss b...

we derived explicit formulae for the eccentric connectivity index and wiener index of2-dimensional square-octagonal tuc4c8(r) lattices with open and closed ends. newcompression factors for both indices are also computed in the limit n-->∞.

The theory of magnetic symmetry in quasicrystals, described in a companion paper [Lifshitz & Even-Dar Mandel (2004). Acta Cryst. A60, 167-178], is used to enumerate all three-dimensional octagonal spin point groups and spin-space-group types and calculate the resulting selection rules for neutron diffraction experiments.