let $r$ be a reversible ring which is $alpha$-compatible for an endomorphism $alpha$ of $r$ and $f(x)=a_0+a_1x+cdots+a_nx^n$ be a nonzero skew polynomial in $r[x;alpha]$. it is proved that if there exists a nonzero skew polynomial $g(x)=b_0+b_1x+cdots+b_mx^m$ in $r[x;alpha]$ such that $g(x)f(x)=c$ is a constant in $r$, then $b_0a_0=c$ and there exist nonzero elements $a$ and $r$ in $r$ such tha...

Let $R$ be a reversible ring which is $alpha$-compatible for an endomorphism $alpha$ of $R$ and $f(X)=a_0+a_1X+cdots+a_nX^n$ be a nonzero skew polynomial in $R[X;alpha]$. It is proved that if there exists a nonzero skew polynomial $g(X)=b_0+b_1X+cdots+b_mX^m$ in $R[X;alpha]$ such that $g(X)f(X)=c$ is a constant in $R$, then $b_0a_0=c$ and there exist nonzero elements $a$ and $r$ in $R$ such tha...

Let (M, g) be a closed Riemannian manifold (m ≥ 2) of positive scalar curvature and (N, h) any closed manifold. We study the asymptotic behaviour of the second Yamabe constant and the second N−Yamabe constant of (M × N, g + th) as t goes to +∞. We obtain that limt→+∞ Y (M ×N, [g+ th]) = 2 2 m+n Y (M ×R, [g+ ge]). If n ≥ 2, we show the existence of nodal solutions of the Yamabe equation on (M × ...

The present work investigates an appropriate way to calculate the 1700 atomic density changes in the reactor operations. To automate this procedure, a computer program has been designed by C#. This program suggests a way to solve this problem which is based on the solution system of differential equations (Bitman) that it is designed according to Runge-Kutta Fehlberg method. The designed softwa...