Relative Roles of Grammar Knowledge and Vocabulary in the Reading Comprehension of EFL Elementary-School Learners: Direct, Mediating, and Form/Meaning-Distinct Effects.

Despite the recognized importance of grammar knowledge to the reading comprehension of EFL learners, research findings on the relationships among grammar knowledge, vocabulary, and reading comprehension are inconclusive. Attention needs to be paid to issues such as the distinct roles of the two grammar knowledge components of form and meaning, and the direct and mediating roles of vocabulary in EFL reading comprehension. This study recruited 1,149 sixth graders as research participants to evaluate these issues.

Experimental investigation of synthetic gas composition in a two-stage fluidized bed gasification process: effect of activated carbon as bed material.

In this study, a two-stage fluidized bed gasifier was used to investigate the effect of the equivalence ratio (ER) and steam/biomass ratio (S/B) on the synthetic gas distribution while activated carbon (AC) was added as the bed material in secondary gasifier (Stage II). The experimental results showed that when the empty bed (without the bed material) was used for the Stage II reaction, the hydrogen (H) content in the synthetic gas emitted from the Stage II reactor was 2-3 mol% higher than that from the first-stage gasifier (Stage I). It was supposed that using the Stage II reactor prolongs the reaction time and thereby increases the H production.

Waste-gasification efficiency of a two-stage fluidized-bed gasification system.

This study employed a two-stage fluidized-bed gasifier as a gasification reactor and two additives (CaO and activated carbon) as the Stage-II bed material to investigate the effects of the operating temperature (700°C, 800°C, and 900°C) on the syngas composition, total gas yield, and gas-heating value during simulated waste gasification. The results showed that when the operating temperature increased from 700 to 900°C, the molar percentage of H2 in the syngas produced by the two-stage gasification process increased from 19.4 to 29.