A. Nejati | Searcharxiv

arXiv2013

On weak $α$-skew McCoy Rings

Let $α$ be an endomorphism of a ring $R$. We introduce the notion of weak $α$-skew McCoy rings which are a generalization of the $α$-skew McCoy rings and the weak McCo rings. Some properties of this generalization are established, and connections of properties of a weak $α$-skew McCoy ring $R$ with $n\times n$ upper triangular $T_n(R)$ are investigated. We study relationship between the weak skew McCoy property of a ring $R$ and it's polynomial ring, $R[x]$. Among applications, we show that a number of interesting properties of a weak $α$-skew McCoy ring $R$ such as weak skew McCoy property in a ring $R$.

math.RA↗

arXiv2013

Electro/Magnetically Induced Controllable Rotation In Small-scale Liquid Flow

We study all the possibilities of producing rotating flow in an incompressible fluid by electric and magnetic fields. We start with a general theoretical basis and look for different configurations and set-ups which electric/magnetic field and an electric current affect the vorticity of fluid resulting in rotation on liquid flow. We assume steady-state conditions and time-independent electric and magnetic fields as the external body torque. Regarding the theoretical basis, we propose three experimental set-ups in which by applying fields on a fluid, rotational vortices are produced: (a) a uniform electric field and a uniform electric current, (b) a uniform electric current and a non-uniform magnetic field, and (c) a non-uniform electric current and a uniform magnetic field. The first case has been reported in detail named "Liquid Film Motor". The two other cases are experimentally investigated here for a cubic an cylindrical cells. The rotational velocity patterns are obtained by PIV technique, and the results are discussed and justified by a preliminary estimation based on the torque exerted by magnetic fields on electric currents. From the log-log plot of angular velocity versus current, the non-linearity factors of the rotational flow for cylindrical and rectangular geometries are obtained.

physics.flu-dyn↗

arXiv2007

Higher Order and boundary Scaling Fields in the Abelian Sandpile Model

The Abelian Sandpile Model (ASM) is a paradigm of self-organized criticality (SOC) which is related to $c=-2$ conformal field theory. The conformal fields corresponding to some height clusters have been suggested before. Here we derive the first corrections to such fields, in a field theoretical approach, when the lattice parameter is non-vanishing and consider them in the presence of a boundary.

cond-mat.stat-mech↗