in this paper, we study some ring theoretic properties of the amalgamated duplication ring $rbowtie i$ of a commutative noetherian ring $r$ along an ideal $i$ of $r$ which was introduced by d'anna and fontana. indeed, it is determined that when $rbowtie i$ satisfies serre's conditions $(r_n)$ and $(s_n)$, and when is a normal ring, a generalized cohen-macaulay ring and finally a filter ring.

Musculoskeletal disorders (MSDs) are common health problem throughout the world and a major cause of disability in the workplace. This study was conducted among workers of a small scale forging Industries. The small scale forging units involve various kinds of high repetitive processes like Blanking, cutting, shearing, furnace loading, hammering, punching and trimming etc. the workers performin...

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...

It has been clarified that deformation and annealing of martensite starting structure can produce ultrafine-grained structure in low carbon steel.  This study aims to investigate the texture evolution and mechanical properties of samples with martensite structure deformed by two different forging processes. The martensitic steel samples were forged by plane strain compression and multi-directio...

This paper analyzes three typical mechanisms of heavy forging robot grippers: pulling with a sliding block including shortand long-leveraged grippers and pushing leveraged grippers, and uses multi-objective evolutionary genetic algorithm to design the optimal forging robot grippers. The decision variables are defined according to the geometrical dimensions of the heavy grippers, and four object...

Studies that examine spatial character-istics of urban unemployment are oftenbased on some simplistic and problematicmeasures of employment accessibility. Thispaper presents a refined methodologicalframework for measuring accessibility,which enables the researcher to (1) improvethe measurement by accounting for job com-petition among workers commuting by dif-...

During the long-term operation, mallets of the forging hammers are exposed to thermal fatigue due to the cyclic temperature changes and impact loads. Taking into account very high price, and a risk of buying frequently the new parts, the necessity of their reparation becomes obvious. The forging hammer mallet (Figure 1), is primarily exposed to the impact compressive loads, and partially also t...