A ring $R$ is called a left Ikeda-Nakayama (left IN-ring) if the right annihilator of intersection any two ideals sum annihilators. As generalization IN-rings, SA-ring annihilators an ideal $R$. It natural to ask IN and SA property can be extended from $R[x; \alpha, \delta]$. In this note, results concerning conditions will allow these properties transfer skew polynomials $R[x;\alpha,\delta]$ a...

a compact and sharp-rejection ultra-wideband (uwb) microstrip band-pass filter (bpf) is developed using of left handed metamaterials realized by complementary split ring resonator (csrr). moreover, proposed structure consists of two doublets parallel coupling gaps at each side of a microstrip ring. in comparison with some other filters, this structure shows a significantly wider passband due to...

a compact and sharp-rejection ultra-wideband (uwb) microstrip bandpass filter (bpf) is presented. the proposed filter is constructed with multiple-mode resonator (mmr) and split ring resonator (srr). moreover, proposed structure consists of two doublets parallel coupling gaps at each side of a microstrip ring. in comparison with some other filters, this structure shows a significantly wider pas...

We construct a commutative ring with identity which extends the ring of characters of finite dimensional representations of sl(3). It is generated by characters with values in the group ring Z[W̃ ] of the extended affine Weyl group of ŝl(3)k at k 6∈ Q. The ‘quantised’ version at rational level k + 3 = 3/p realises the fusion rules of a WZW conformal field theory based on admissible representatio...

In the title compound, C(10)H(9)N(3)O(3), the benzene ring is almost coplanar with the heterocyclic ring, making a dihedral angle of 11.3 (1)°. The plane of the carboxyl group is rotated by 8.4 (2)° with respect to the 1,2,4-oxadiazole ring plane. The aliphatic chain exhibits an extended conformation. In the crystal, mol-ecules are liked through inter-molecular O-H⋯N bonds, forming a chain stru...

The title compound, C(18)H(15)NO(3), consists of an indolizine ring system and an aromatic ring. The two ring systems are not coplanar, the dihedral angle between the two being 54.26 (7)°. In the crystal, inversion dimers are formed by weak C-H⋯O interactions. These dimeric groups are further extended to form a regular two-dimensional structure by additional weak C-H⋯O inter-actions.

The title compound, C(20)H(14)F(4)N(4), is a flexible bis-pyridine-type ligand with an extended fluorinated spacer group between the two pyridyl functions. The centroid of the central aromatic ring is situated on a crystallographic center of inversion. The dihedral angle between the pyridine ring and the central benzene ring is 63.85 (9)°. The crystal structure exhibits inter-molecular C-H⋯F hy...

W. H. Tutte’s 1947 paper on a ring generated by graphs satisfying a contraction-deletion relation is extended to ribbon graphs. This ring of ribbon graphs is a polynomial ring on an infinite set of one-vertex ribbon graphs. Acknowledgements: The LSU Research Experience for Undergraduates Program is supported by a National Science Foundation grant, DMS-0648064. Page 16 RHIT Undergrad. Math. J., ...