In the title compound, C(18)H(20)O(4)S, the thio-phene and benzene rings are oriented at a dihedral angle of 10.83 (11)°. The central chain makes dihedral angles of 1.86 (13) and 9.25 (12)° with the benzene and thio-phene rings, respectively. In the crystal, mol-ecules are linked through weak inter-molecular C-H⋯O inter-actions. π-π inter-actions are also observed between the benzene rings with...

We report the discovery of a double ring structure in the waist of the nebula surrounding η Carinae. The rings are detected in the mid-IR dust continuum at wavelengths of 7.9, 11.9, 12.9 and 20 µm. The dust in the rings has a temperature of about 300 K. The orientation of the rings is inclined with respect to the axis of the homunculus by either 37 or 58 degrees. The central star is not in the ...

Rings are common in disk galaxies. These rings are either indistinguishable from a pair of tightly wound spirals, or themselves are a part of the spiral structure. Furthermore, their occurrence is seen coincident with a bar in the center. In this paper, we interpret this spiral-ring structure as density waves resonantly excited by a rotating bar potential. The theory gives excellent agreement f...

The title Schiff base compound, C(23)H(23)N(5)O, was synthesized by the reaction of 4-amino-phenazone and 3,5-dimethyl-1-phenyl-pyrazole-4-carbaxaldehyde. The mol-ecule adopts an E configuration about the central C=N double bond. A weak intra-molecular C-H⋯O hydrogen bond generates an S(6) ring motif. The dihedral angle between the pyrazole rings is 24.72 (10)° and the dihedral angles between t...

In the title mol-ecule, C(17)H(11)N(11), the five rings are almost coplanar [maxium deviation 0.1949 (1) Å]. The dihedral angles between the two pyrazine rings and the two triazole rings are 1.52 (4) and 2.51 (5)°, respectively. The central pyridine ring forms dihedral angles of 5.57 (1) and 1.71 (1)° with the two triazole rings. The crystal packing consists of a three-dimensional network struc...

Abstract During an extensive test programme at the Bundesanstalt für Materialforschung und prüfung, material property changes of EPDM O-rings were investigated different ageing times and two temperatures $$125\,^{\circ }\,\hbox {C}$$ 125 ∘ C</mm...

Central venous stenosis is a well-known complication in patients with vascular access for hemodialysis. We report two cases involving patients on hemodialysis with arteriovenous fistulas who developed reversible unilateral conductive hearing loss secondary to critical stenosis of central veins draining the arteriovenous dialysis access. A proposed mechanism for the patients' reversible unilater...

Today, the use of CMOS technology for the manufacture of electronic ICs has faced many limitations. Many alternatives to CMOS technology are offered and made every day. Quantum-dot cellular automata (QCA) is one of the most widely used. QCA gates and circuits have many advantages including small size, low power consumption and high speed. On the other hand, using special digital gates called re...

In this paper, we introduce and study a strict generalization of symmetric rings. We call ring $R$ \textit{`$P$-symmetric' } if for any $a,\, b,\, c\in R,\, abc=0$ implies $bac\in P(R)$, where $P(R)$ is the prime radical $R$. It shown that class $P$-symmetric rings lies between central generalized weakly Relations are provided some other known classes From an arbitrary ring, produce many families