We define and studyco-Noetherian dimension of rings for which the injective envelopeof simple modules have finite Krull-dimension. This  is a Moritainvariant dimension that measures how far the ring is from beingco-Noetherian. The co-Noetherian dimension of certain rings,including commutative rings, are determined. It is shown that the class ${mathcal W}_n$ of rings with co-Noetherian dimension...

a module m is called epi-retractable if every submodule of m is a homomorphic image of m. dually, a module m is called co-epi-retractable if it contains a copy of each of its factor modules. in special case, a ring r is called co-pli (resp. co-pri) if rr (resp. rr) is co-epi-retractable. it is proved that if r is a left principal right duo ring, then every left ideal of r is an epi-retractable ...

Au cours des deux dernières décennies des psychologues et des linguistes informaticiens ont essayé de modéliser l'accès lexical en construisant des simulations ou des ressources. Cependant, parmi ces chercheurs, pratiquement personne n'a vraiment cherché à améliorer la navigation dans des 'dictionnaires électroniques destinés aux producteurs de langue'. Pourtant, beaucoup de travaux ont été con...

The estimation of pollution fields, especially in densely populated areas, is an important application in the field of environmental science due to the significant effects of air pollution on public health. In this paper, we investigate the spatial distribution of three air pollutants in Tehran’s atmosphere: carbon monoxide (CO), nitrogen dioxide (NO2), and atmospheric particulate matters less ...

The estimation of pollution fields, especially in densely populated areas, is an important application in the field of environmental science due to the significant effects of air pollution on public health. In this paper, we investigate the spatial distribution of three air pollutants in Tehran’s atmosphere: carbon monoxide (CO), nitrogen dioxide (NO2), and atmospheric particulate matters less ...

background: specific growth factors and feeder layers seem to have important roles in in vitro embryonic stem cells (escs) differentiation. in this study,the effects of bone morphogenetic protein 4 (bmp4) and mouse embryonic fibroblasts (mefs) co-culture system on germ cell differentiation from mouse escs were studied. materials and methods: cell suspension was prepared from one-day-old embryoi...

background new research proposes the pluripotency of spermatogonial cells obtained from testis. these spermatogonia-derived stem cells are called embryonic stem-like cells that express embryonic stem cell markers and differentiate to the three germ layers. objectives the aim of the present study was to generate embryonic stem-like cells from neonatal mouse testis. materials and methods the test...

Cobalt oxide (Co3O4) nanorods were prepared by a simple co-precipitation method using ethanol solution of cobalt nitrate as precursor and cetyl trimethylammonium bromide (CTAB) as surfactant. Morphological properties of the nanoparticles were characterized. XRD measurement exhibited the structure of Co3O4 nanocrystals for annealed samples. The SEM ima...

In the past decade, magnetic nanomaterials have attracted much attention due to their physical properties and technological applications. In this work, α-Fe2O3 nanoparticles were first synthesized via a simple co-precipitation method using iron chloride hexahydrate (FeCl3.6H2O) as precursor and ammonia solution as precipitator. The samples we...