In the title compound, C(22)H(19)NO, the dihedral angle between the benzene ring and the carbazole ring system 77.1 (1)°.. The crystal structure is stabilized by inter-molecular aromatic π-π inter-actions between the benzene ring and the pyrrole ring of the carbazole system of neighbouring mol-ecules [centroid-centroid distance = 3.617 (4) Å]. In addition, the crystal structure exhibits a weak ...

we introduce center-like subsets z*(r,f), z**(r,f) and z1(r,f), where r is a ring and f is a map from r to r. for f a derivation or a non-identity epimorphism and r a suitably-chosen prime or semiprime ring, we prove that these sets coincide with the center of r.

for an arbitrary ring $r$, the zero-divisor graph of $r$, denoted by $gamma (r)$, is an undirected simple graph that its vertices are all nonzero zero-divisors of $r$ in which any two vertices $x$ and $y$ are adjacent if and only if either $xy=0$ or $yx=0$. it is well-known that for any commutative ring $r$, $gamma (r) cong gamma (t(r))$ where $t(r)$ is the (total) quotient ring of $r$. in this...

let r be a prime ring with extended centroid c, h a generalized derivation of r and n ⩾ 1 a xed integer. in this paper we study the situations: (1) if (h(xy))n = (h(x))n(h(y))n for all x; y 2 r; (2) obtain some related result in case r is a noncommutative banach algebra and h is continuous or spectrally bounded.

The crystal structure of the title compound, C25H24N2O2, at 173 K has monoclinic (C2/c) symmetry. The mol-ecule is located on a crystallographic twofold rotation axis with only half a mol-ecule in the asymmetric unit. The imidazolidine ring adopts a twist conformation, with a twist about the ring C-C bond. The crystal structure shows the anti-clinal disposition of the two (2-hy-droxy-naphthalen...

Let F be Thompson’s group, with presentation 〈x0, x1, x2, . . . ; x xi n = xn+1 for i < n 〉 . Geoghegan and I showed in the early 1980s that Hn(F ) is free abelian of rank 2 for all n ≥ 1. It turns out that the homology admits a natural ring structure, which I calculated a few years later but never published. With the aid of this ring structure one can also calculate the cohomology ring. In thi...

a ring $r$ is a strongly clean ring if every element in $r$ is the sum of an idempotent and a unit that commutate. we construct some classes of strongly clean rings which have stable range one. it is shown that such cleanness of $2 imes 2$ matrices over commutative local rings is completely determined in terms of solvability of quadratic equations.

Abstract: Zirconia solid electrolytes with nonequilibrium composite structure were prepared by impregnation of a porous 8YSZ matrix with a solution of Zirconia. Microstructures were characterized by XRD and SEM. The electrical properties were studied by impedance spectroscopy as a function of temperature. Biaxial flexural strength and fracture toughness of composite samples were measured by rin...

Let G be a compact Lie group and kG a G spectrum (as defined in [3, Section I.2]). Greenlees and May ([2]) have defined an associated G-spectrum t(kG) called the Tate spectrum. They observe that if kG is a ring G-spectrum then there is an induced ring G-spectrum structure on t(kG), and that if kG is homotopy-commutative then t(kG) will also be homotopycommutative (see [2, Proposition 3.5]). It ...

In the structure of the title compound, C(15)H(14)O(2)S, the benzene ring is nearly coplanar with the thio-phene ring. The hydroxy group substituted at C2 position is in an antiperi-planar conformation with respect to the phenyl ring. The crystal structure exhibits weak intramolecular O-H⋯O hydrogen bonding.