منابع مشابه
Double Ore Extensions versus Iterated Ore Extensions
Motivated by the construction of new examples of Artin-Schelter regular algebras of global dimension four, J.J.Zhang and J.Zhang (2008) introduced an algebra extension AP [y1, y2;σ, δ, τ ] of A, which they called a double Ore extension. This construction seems to be similar to that of a two-step iterated Ore extension over A. The aim of this paper is to describe those double Ore extensions whic...
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BACKGROUND For persons with unicompartment knee osteoarthritis (OA), off-unloader braces are a mechanical intervention designed to reduce pain, improve physical function, and possibly slow disease progression. Pain relief is thought to be mediated by distracting the involved compartment via external varus or valgus forces applied to the knee. In so doing, tibiofemoral alignment is improved, and...
متن کاملGalois Subrings of Ore Domains Are Ore Domains
If JR is a ring, and G is a group of automorphisms of R, then R denotes the subring of R consisting of elements of R left fixed by every element of G, and is called the Galois subring corresponding to G. In his paper, Groups acting on hereditary rings, G. M. Bergman has asked if every Galois subring of a right Ore domain corresponding to a finite group is itself right Ore. In this note we show ...
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Due to economical and environmental issues, utilization of mineral wastes, e.g. iron ore mine tailing (IOMT), as road materials can be recommended as a sustainable alternative. In the present study, mechanical properties, as well as resistance to freezing and thawing cycles (F-T) of low plasticity clay soil stabilized with different percentages of Portland cement (0, 6, 9, 12 and 15%) and diffe...
متن کاملFibers in Ore extensions
LetR be a finitely generated commutative algebra over an algebraically closed field k and let A = R[t;σ, δ] be the Ore extension with respect to an automorphism σ and a σ-derivation δ. We view A as the coordinate ring of an affine non-commutative space X. The inclusion R → A gives an affine map ξ : X → SpecR, and X is a non-commutative analogue of A 1 ×SpecR. We define the fiber Xp of ξ over a ...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1900
ISSN: 0036-8733
DOI: 10.1038/scientificamerican01061900-7