Context. Neptune’s incomplete ring arcs have been stable since their discovery in 1984 by stellar occultation. Although these structures should be destroyed within a few months through differential Keplerian motion, imaging data over the past couple of decades shown that remain stable.

Molodtsov introduced the theory of soft sets, which can be seen as an effective mathematical tool to deal with uncertainties, since it is free from the difficulties that the usual theoretical approaches have troubled. In this paper, we apply the definitions proposed by Ali et al. [M. I. Ali, F. Feng, X. Liu, W. K. Min and M. Shabir, On some new operations in soft set theory, Comput. Math. Appl....

A terahertz microscope has been used to excite and observe the resonant modes of a single split ring resonator in the reactive and radiative near-field zones. The two lowest resonant modes of an isolated split ring resonator with their corresponding radiation patterns are reported; they showed good agreement to simulations. The passage from the reactive to radiative near-field zone is also disc...

We report on direct measurements of the magnetic near-field of metamaterial split ring resonators at terahertz frequencies using a magnetic field sensitive material. Specifically, planar split ring resonators are fabricated on a single magneto-optically active terbium gallium garnet crystal. Normally incident terahertz radiation couples to the resonator inducing a magnetic dipole oscillating pe...

The title compound, C(25)H(22)N(2)O(3), with three stereogenic centres, crystallizes in a centrosymmetric space group as a racemate. The pyran ring adopts a sofa conformation and the five-membered isoxazole ring exhibits an envelope conformation. The dihedral angle between the benzene ring and the mean plane through the near coplanar atoms of the pyran ring is 10.54 (9)°. In the crystal, no sig...

We have studied the formation of rings in the disks of galaxies by using two-dimensional N-body simulations where the gas component is modelled as dissipatively colliding test particles. Our results support the standard hypothesis that ring formation occurs when gas is driven to resonances by the gravitational torque of a rotating stellar bar. When the bar is absent, a weaker oval-shaped mode o...

The title compound, C(25)H(23)NO(5), comprising two stereogenic carbon atoms of the same configuration, crystallizes in a centrosymmetric space group as a racemate. The six-membered pyran ring and the five-membered isoxazole ring adopt sofa and twisted conformations, respectively. The dihedral angle between the benzene ring and the mean plane through the near coplanar atoms of the pyran ring is...

The motivation of this article is to define approximately near rings, some types $N$-groups, ideals, and rings all descriptive cosets. Moreover, properties these algebraic structures are given. Furthermore, near-ring homomorphisms introduced their investigated.

Optoelectronic integrated circuits incorporating twin ring diode lasers with InAs/InGaAs/GaAs quantum-dot active region have been fabricated and characterized. Directional control and unidirectional operation of ring diode lasers are demonstrated by forward biasing an S-section waveguide incorporated within the ring cavity. Mode-beating spectra from individual ring diode lasers are observed at ...