For redundant second-class constraints the Dirac brackets cannot be defined and new brackets must be introduced. We prove here that the Jacobi identity for the new brackets must hold on the surface of the second-class constraints. In order to illustrate our proof we work out explicitly the cases of a fractional spin particle in 2 + 1 dimensions and the original Brink-Schwarz massless superparti...

Writing projects are socially-situated identities. The rhetorically-loaded aspects of writing, like metadiscourse marking, are more prone to carry such identities. Through analyzing metadiscourse strategies employment in Persian and English (as the lingua franca of academic discourse community) research articles, this study makes an attempt to find out whether Persian native writers take on the...

The transition from the industrial age and the growing impact of the global economy on human life which has led to rapid expansion of western urban design culture in countries like Iran, are among the reasons why nowadays there is only a memory left in our minds of our traditional cities. "Urban identity" is one of the most important and most controversial issues among urban designers and other...

Along the history, relations between Iran and Russia always faced with great changes and transitions and always, the foundation of these relations have been on the base of political, security and military and sometimes economical affairs. Iran and its people have special identity elements like: Persian language, Shiite Islamism, nationalism, regional hegemonies, anti-foreignism and etc, that so...

We introduce center-like subsets Z*(R,f), Z**(R,f) and Z1(R,f), where R is a ring and f is a map from R to R. For f a derivation or a non-identity epimorphism and R a suitably-chosen prime or semiprime ring, we prove that these sets coincide with the center of R.