the present study investigated comparatively the impact of two types of input enhancement (i.e. textual vs. compound enhancement) on developing grammar ability in iranian efl setting. sixty-five female secondary high school students were selected as a homogenous sample out of about a 100-member population based on nelson language proficiency test. then, their grammar ability was measured based ...

during the last decade, the expansion of urbanization and industrial activities caused serious environmental problems such as soil pollution. novel technologies are required to remediate soil contamination with toxic contaminants, including heavy metals and organic pollutants. in recent years, there have been increasing attempts to improve soil remediation efficiency. electrokinetic (ek) is an ...

The paper presents preliminary results of an experimental study on solar water heater with full width and 75% twisted tapes as heat transfer enhancement device. The study shows that the thermal efficiency due the use of the twisted tape increases by 4.5-8%; higher for the 75% twisted tape. Keyword Solar water heater (collector), tube-in-fin, twisted tape, thermal efficiency, performance enhance...

GaInP/GaAs/Ge triple-junction concentrator solar cells with significant efficiency enhancement were demonstrated with antireflective ZnO nanoneedles. The novel nanostructure was attained with a Zn(NO3)2-based solution containing vitamin C. Under one sun AM 1.5G solar spectrum, conversion efficiency of the triple-junction device was improved by 23.7% via broadband improvement in short-circuit cu...