we find a criterion for a morphism of coalgebras over a barr-exact category to be effective descent and determine (effective) descent morphisms for coalgebras over toposes in some cases. also, we study some exactness properties of endofunctors of arbitrary categories in connection with natural transformations between them as well as those of functors that these transformations induce between co...

Hydraulic fracturing in the fractured reservoirs plays a significant impact on the production rate. In this study, the hydrostatic condition is taken into account, the hydraulic fracturing operation was applied in every direction usinga written distinct element code. In each direction the hydraulic fracture is applied with different lengths and in each level the amount of production is predicte...

This paper continues the study of the connection between hyper- groups and fuzzy sets, investigating the length of the sequence of join spaces associated with a hypergroup. The classes of complete hypergroups and of 1-hypergroups are considered and analyzed in this context. Finally, we give a method to construct a nite hypergroup with the strong fuzzy grade equal to a given natural number

hydraulic fracturing in the fractured reservoirs plays a significant impact on the production rate. in this study, the hydrostatic condition is taken into account, the hydraulic fracturing operation was applied in every direction usinga written distinct element code. in each direction the hydraulic fracture is applied with different lengths and in each level the amount of production is predicte...