background and purpose     methods:     results:     conclusion:

sizing of paperboard has a distinctive position in packaging grade paperboard material. optimization of sizing by alum-rosin at neutral ph in 4 layered paperboard (330 g/m2) wereevaluated in this study to find the optimum ratio of alum- rosin loading in the process. fixed amount of 1% cationic dispersed rosin together with alum as a fixing agent at 5 different levels of 1, 1.5, 2, 3, and 4% (ba...

drought as a climatic phenomenon affected many different environmental issues and generally is associated with the decreasing in average precipitation. evaluation and monitoring of the drought is a fundamental step in proper programming of water resources management. regarding the recent conditions water scarcity in the urmia lake basin, assessment of the drought index in this region is inevita...

this research in order to identify and introduction of  cotton  suitable cultivar  or cultivars for the double cropping of after wheat and canola harvesting  was carried out in the northern region of ardebil province. in this study, eight  varieties  of    imported cotton germplasm resources in recent years were chosen   and   with the iran's cultivars included  mehr  and varamin  were eva...

melamine trisulfonic acid (mtsa) as an efficient heterogeneous catalyst has been used for the one-pot preparation of triazolo[1,2-a]indazole-1,3,8-trione and 2h-indazolo[2,1-b]phthalazine-1,6,11-trione derivatives by the three-component condensation reaction of urazoles or phthalhydrazide, dimedone or 1,3-cyclohexanedione, and aldehydes under solvent-free conditions in good to excellent yields ...

to examine the effect of mixing graminicide herbicides with liquid fertilizer in gorgan region, an experiment was conducted as factorial arranged in complete randomized block design (rcbd) with three replications at the research farm of islamic azad university of gorgan. the first factor was using topic, pumasuper and axial herbicides with the amounts of 0.8, 1, and 0.5 l/ha-1, respectively. th...

the objective followed in this study was to determine the amen equivalency of multienzyme natuzyme-p. one hundred and sixty male ross 308 broiler chicks were made use of in the experimentations. graded levels of amen, 2600, 2750, 2900, plus 3050 kcal/kg in the starter, and 2700, 2850, 3000, plus 3150 kcal/kg of the diet in the grower periods were used throughout the study. all the nutrients oth...

in order to comparison the foliar application of biological, biostimulator and chemical fertilizers on growth characteristics and yield of saffron, a factorial experiment was conducted in a completely randomized block design with four replication in 3- year field of saffron in dargaz, khorasan razavi province from 2010 to 2011. the first factor had 5 levels included biostimulator fertilizer bio...

the present study carried out an in vitro experiment on effects of salinity and temperature on acartia tonsa life cycle from caspian sea. during the experiment, temperature and salinity ranged 25, 27, 29 ± 1 °c and 12‰ and 17‰, respectively within a period of 60 days. spawning rate was measured using mesh size of 100 µ planktonic net from surface to 10 m depth. early results show that nauplii a...

forest cover is one of the most effective factors in reducing flooding in northern iran, so that in recent years the destruction, land use changing and uncontrolled harvesting of forest areas, has greatly increased the number and magnitude of floods. so far, there have been few studies on forest hydrology in iran, particularly the northern hyrcanian forests. this study examines the impact of a ...