In this paper we introduce derivations in Krasner hyperrings and derive some basic properties of derivations. We also prove that for a strongly differential hyperring $R$ and for any strongly differential hyperideal $I$ of $R,$ the factor hyperring $R/I$ is a strongly differential hyperring. Further we prove that a map $d: R rightarrow R$ is a derivation of a hyperring $R$ if and only if the in...

nowadays, agricultural r&d provides new and developed technologies to create modern agricultural producing methods. during recent years, improving agricultural productivity is affected by not only domestic r&d investments but also foreign countries r&d investments. nowadays, according to new growth models, r&d is the base of productivity. recent economic theories consider agricu...

this study investigates correlation between journal self – citation and impact factor in agriculture and veterinary subject category through the scientific journals indexed in isc's pjcr during 2001 to 2007. citation analysis is used to conduct the research. the results indicate a significant correlation between impact factor and journal self – citation (r=0.425, sig= 0.000); that is, journals ...

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...

a field experiment was conducted to evaluate the effect of varying doses of haloxifhope-r-methyl ester herbicide on grass weeds grown at various stages in 2011-2012 growing season in research farm of college of agriculture, shiraz university. the study was carried out as split split plot based on randomized complete block design with three replicates. treatments were haloxifhope-r-methyl ester ...