in this paper, we introduce a class of $j$-quasipolar rings. let $r$ be a ring with identity. an element $a$ of a ring $r$ is called {it weakly $j$-quasipolar} if there exists $p^2 = pin comm^2(a)$ such that $a + p$ or $a-p$ are contained in $j(r)$ and the ring $r$ is called {it weakly $j$-quasipolar} if every element of $r$ is weakly $j$-quasipolar. we give many characterizations and investiga...

This paper provides a method for a controllable nonholonomic mechanical system. By use of the nonholonomy of the disk’s rolling constraint in the plane and the condition of chained form conversion, a multi-joint nonholonomic manipulator, which uses only two actuators and can be converted into chained form and achieves control simplicity, is presented. The Frobenius and Chow theorems prove that ...

in this paper, we investigate various kinds of extensions of twin-good rings. moreover, we prove that every element of an abelian neat ring r is twin-good if and only if r has no factor ring isomorphic to z2  or z3. the main result of [24] states some conditions that any right self-injective ring r is twin-good. we extend this result to any regular baer ring r by proving that every element of a...

Cereal Chern. 81(3):345-349 Grain sorghum can be a major source of policosanols, long-chained alcohols, that have beneficial physiological activities. Sorghum dried distillers grains (DDG), a by-product of ethanol production from grain sorghum. contain a large amount of policosanols. Content and composition of policosanols in long-chained lipids extracted from grain sorghum kernels and DDG were...

For any complete chain I whose distinct elements are separated by cover pairs, and for every family {Mi | i∈ I} of monoids, we construct a family of graphs {Gi | i∈ I} such that Gi is a proper induced subgraph of Gj for all i; j∈ I with i ¡ j, Gi = ⋂ {Gj | j∈ I; i ¡ j} whenever i = inf{ j∈ I | j¿ i} in I , Gi = ⋃ {Gj | j∈ I; j ¡ i} whenever i = sup{ j∈ I | j¡ i} in I , the endomorphism monoid o...

Recently, a lot of research concerning co-evolution has been done. Co-evolution is a brand new approach that tries to find a solution for the problem of the missing link between the design and the implementation of object-oriented software systems. To date this has been done by using a rule-based backward chained reasoning mechanism as a declarative meta layer on top of the implementation of an...