Rapid intensification of Vietnamese rice production has had a positive effect on the nation's food and economy. However, sustainability intensive is increasingly being questioned within Vietnam, particularly in major agricultural provinces such as An Giang. The construction high dykes this province, which allow for complete regulation water onto fields, enabled farmers to grow up three crops pe...

Let d be a square-free positive integer, let Od denote the ring of integers in Q( √ −d), and let Qd denote the Bianchi orbifold H/PSL(2,Od). A non-compact finite volume hyperbolic 3-manifold X is called arithmetic if X and Qd are commensurable, that is to say they share a common finite sheeted cover (see [26] Chapter 8 for more on this). If N is a closed orientable 3-manifold and L ⊂ N a link, ...

Given a graph covering, there is an induced surjection of critical groups. We will try to determine the structure of the kernel and give results at different levels of generality. A main tool will be dualizing the short exact sequence and working instead with the cokernel. In the case of signed graphs and two-sheeted coverings, we will show that the kernel of the induced surjection can be descr...

the subduction of the northern part of the tethys is documented by arc magmatism from upper triassic to lower eocene crosscutting the sanandaj-sirjan zone and from upper eocene to plio-quaternary in the urumieh-dokhtar magmatic zone, situated north of the ssz. neyriz ophiolite is part of middle eatern neo-tethyan ocean of mesozoic that geographically is related to ophiolites of nw-se iran, alon...