We consider a free action of an Ore semigroup on a higher-rank graph, and the induced action by endomorphisms of the C ∗-algebra of the graph. We show that the crossed product by this action is stably isomorphic to the C ∗-algebra of a quotient graph. Our main tool is Laca’s dilation theory for endomorphic actions of Ore semigroups on C ∗-algebras, which embeds such an action in an automorphic ...

Currently, archival practice is moving towards the definition of complex relationships between the resources of interest as well as the constitution of compound digital objects. To this end archives can take advantage of using the Open Archives Initiative Object Reuse and Exchange (OAI-ORE) providing additional and flexible visualizations of archival resources. In this paper we define a formal ...

We prove the following result on the universal localization of a ring R at an ideal I: If the universal localization is flat as an R-module, then R satisfies the Ore condition with respect to the multiplicative set of elements that become invertible modulo I. It is well known that for domains the converse of this result holds, and hence we have found in this case a new characterization of the O...

In this work, the shaft furnace reactor of the MIDREX® process is simulated. This is a counter current gas-solid reactor, which transforms iron ore pellets into sponge iron. Simultaneous mass and energy balance along the reactor leads to a set of ordinary differential equation with two points boundary conditions. The iron ore reduction kinetics was modelated with the unreacted shrinking core mo...

Abstract. We construct several families of Artin-Schelter regular algebras of global dimension four using double Ore extension and then prove that all these algebras are strongly noetherian, Auslander regular, Koszul and CohenMacaulay domains. Many regular algebras constructed in the paper are new and are not isomorphic to either a normal extension or an Ore extension of an Artin-Schelter regul...

Introduction This paper seeks to define a new method for representing and managing description of archival collections using OAI-ORE. This new method has two advantages. Firstly, it adapts traditional archival description methods for the contemporary reality that digital collections, unlike collections of physical materials, are not best described by physical location. Secondly, it takes advant...

Necessary and sufficient conditions for an Ore extension S = R[x;σ, δ] to be a PI ring are given in the case σ is an injective endomorphism of a semiprime ring R satisfying the ACC on annihilators. Also, for an arbitrary endomorphism τ of R, a characterization of Ore extensions R[x; τ ] which are PI rings is given, provided the coefficient ring R is noetherian.

in this study, the isothermal reduction of iron oxide pellets, made of iranian chadormalo, gole-gohar, and sangan iron ores, was investigated in the temperature range of 900-1100°c. tabas, pabdana, babnizoo, karmozd, and shahrood domestic coals were used as reductants. parametric studies were performed and the effects of such factors as temperature, average particle size of iron ore and coal fi...

Iron ore concentrate is enriched by flotation prior to form iron ore green pellets in order to reduce phosphorus content in the ore concentrate. A flotation reagent is used in this process and it is known to incorporate air bubbles and eventually deteriorate the strength of the pellets. These bubbles were therefore characterized both qualitatively and quantitatively by cryogenic scanning electr...