We study the conductance of mesoscopic graphene rings in the presence of a perpendicular magnetic field by means of numerical calculations based on a tightbinding model. First, we consider the magnetoconductance of such rings and observe the Aharonov-Bohm effect. We investigate different regimes of the magnetic flux up to the quantum Hall regime, where the Aharonov-Bohm oscillations are suppres...

Let R be a commutative ring with identity , and M is unitary left R-module”, “A proper submodule E of an R-module called weakly quasi-prime if whenever r, s ∈ R, m M, 0 ≠ rsm implies that rm or sm E”. “We introduce the concept quasi 2-absorbing as generalization submodule”, where r,s,t ∈M 0≠ rstm rtm stm E. we study basic properties 2-absorbing. Furthermore, relationships other classes module a...

the verse on “the world of primal covenant (‘alam al-zarr)” is among difficult quranic verses whose difficulty can be discovered by consideration of different opinions, which are sometimes opposite to one another, presented by quranic commentators. having accepted the existence of “the world of primal covenant,” mulla sadra has interpreted and expounded that world in accordance with his philoso...

A partition of a finite abelian group gives rise to a dual partition on the character group via the Fourier transform. Properties of the dual partitions are investigated and a convenient test is given for the case that the bidual partition coincides the primal partition. Such partitions permit MacWilliams identities for the partition enumerators of additive codes. It is shown that dualization c...

A solution to the problem posed by Isbell in the early 1970s of how to determine all varieties (in the sense of universal algebra) equivalent to a given variety is presented. The method is based on the use of Lawvere theories. It is shown how the known characterizations of rings, Morita equivalent to a given one, and of monoids, Morita equivalent to a given one, and also how (even an extension ...

A general ordertheoretic linear programming model for the study of matroid-type greedy algorithms is introduced. The primal restrictions are given by so-called weakly increasing submodular functions on antichains. The LP-dual is solved by a Monge-type greedy algorithm. The model ooers a direct combinatorial explanation for many integrality results in discrete optimization. In particular, the su...

The order of accuracy of the node-centered finite volume methods is analyzed, and the analysis is based on an exact derivation of the numerical errors in one dimension. The accuracy for various types of grids are considered. Numerical simulations and analysis are performed for both a hyperbolic and a eliptic case, and the results agree. The impact of weakly imposed boundary conditions is analyz...

This paper presents the current fastest known weakly polynomial algorithm for the submodular flow problem when the costs are not too big. It combines Röck’s or Bland and Jensen’s cost scaling algorithms, Cunningham and Frank’s primal-dual algorithm for submodular flow, and Fujishige and Zhang’s push-relabel algorithm for submodular maximum flow to get a running time of O(nh logC), where n is th...

The classes of clean and nil-clean rings are closed with respect standard constructions as direct products and (triangular) matrix rings, cf. [12] resp. [4], while the classes of weakly (nil-)clean rings are not closed under these constructions. Moreover, while all matrix rings over fields are clean, [12] when we consider nil-clean rings there are strongly restrictions: if a matrix ring over a ...

The title compound, C(34)H(32)O(6)S, is an ido-configured thio-glycoside building block for heparan sulfate fragments. It contains disordered tolyl and O-benzyl groups with occupancy ratios of 0.539 (13):0.461 (13) and 0.613 (13):0.387 (13), respectively, as determined from a weakly diffracting crystal. The fused rings adopt chair conformations with the mol-ecules packing into a three-dimension...