The authors studied the direct conversion of syngas to light paraffins in a dual-bed fixed-bed reactor. A catalyst composed three catalysts, physically mixed methanol synthesis (CZA), and dehydration dimethyl ether (DME) (Al2O3(C)) were put upper bed for DME, while SAPO-34 (SP34-C) zeolite was lower DME conversion. effects mass ratio CZA Al2O3(C), H2/CO molar ratio, space velocity on catalytic ...

The paper describes the strategy for efficient solving of difficult inverse problems, utilizing Finite Element Method (FEM) as a direct problem solver. The strategy consists of finding an optimal balance between the accuracy of global optimization method and the accuracy of an hp-adaptive FEM used for the multiple solving of the direct problem. The crucial relation among errors was found for th...

this study intended to develop a model describing speaking strategies for efl learners by taking into account the effects of learners’ gender and proficiency on the application of strategies. accordingly, this study was planned to have two main analyses, namely qualitative and quantitative. in this respect, 30 efl learners' viewpoints were sought, and then, based on the elicited responses, a 21...

in order to investigate rice competition ability against weeds in direct-seeding and transplanting systems afield experiment was conducted at mahmud abad region of mazandaran province on 2011 growing season. experimental treatments were studied in a split plot factorial design based on randomized complete blocks with three replicates. direct-seeding and transplanting of rice in wet seedbed were...

An important recent finding is that testing improves learning and memory. In this article, the authors describe a demonstration that illustrates this principle and helps students incorporate more testing into their learning. The authors asked students to read one text using a Study–Study strategy and one text using a Study–Test strategy. One week later, the authors tested students’ memory for b...

De Vrijer has presented a proof of the finite developments theorem which, in addition to showing that all developments are finite, gives an effective reduction strategy computing longest developments as well as a simple formula computing their length. We show that by applying a rather simple and intuitive principle of duality to de Vrijer’s approach one arrives at a proof that some developments...