in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands ...

Abstract This research aims at studying and assessing factors affecting on tax lags in Iran. The statistical population of study consists of 45 active manufacturing companies in the center of Mazandaran province that have filed and submitted their tax returns and related documents during the years 2009 to 2013, and their final taxes have been determined and have reached to the stage of collect...