one of the most important atmospheric systems in the eurasian continent during the northern hemisphere winter season is the siberian high pressure. in this study, using the ncep/ncar reanalysis data for winters of 1948-2008, trend of changes in the intensity of the high system center and its effects on some meteorological fields are investigated. the results show that the 2m height mean tempera...

introduction precipitation is one of the most important meteorological variables in comparison with other climatic parameters. it varies extremely over time and space. the occurrence of this climate phenomenon requires specific circumstances in environment. its accurate measurement is important to a wide range of decision makers including hydrologists, agriculturalists, industrialists and etc. ...

introduction atmospheric circulation patterns leads to different weather conditions and rainfall regime change is controlled by seasonal and irregular variations of atmospheric circulation pattern. variety and climate change, such as drought and flood result in changes in the spatio-temporal of precipitation, one of the important parameters conditions mentioned, heterogeneity in moisture transm...

the present study was conducted to determine the effects of different levels of rice bran along with a multi enzyme on the performance of broiler chicks. three hundred eighty four day-old male broiler chicks were taken in 8 treatments comprised of different levels of rice bran (0, 6, 12 and 18%) together with a multi enzyme (0 and 0.1%). each treatment was carried out in 4 replicates each repli...

introduction there are significant differences in the spatial distribution of the iran annual precipitation. this is resulted from spatial behavior of precipitation in the one hand and variation in the sources of precipitation on the other. the lack of adequate distribution of meteorological stations and the unavailability of long-term statistics of precipitation makes the analysis of precipita...

this study was carried out to evaluate the effect of commercial live bakery’s’ yeast( saccharomyces cerevisiae ), (marketed as amax), on growth and survival of persian sturgeon( acipenser persicus) larvae (74.9 ± 9.7mg) during 30 days. sturgeon larvae were fed on daphnia magna enriched at three suspensions of yeast, amax, (0, 50, 100, and 150 mg yeast per litter). the feeding level was 30 perce...

earthworms are an important part of food chain in soil ecosystem. in polluted soils, heavy metals are consumed by earthworms and transferred to other organisms through food chain, resulting in many adverse health impacts. due to the benefits of earthworms for soil fertility, it is important to assess the effects of soil pollution on population, biomass and functions of earthworms. to determine ...

to inspect the effect of methyl salicylate (mesa) vapor on fruit shelf life quality in kiwifruit (actinidia chinensis cv. hayward) an experiment was carried out in citrus research institute, ramsar, iran in 2006-2007. the experiment was based on a completely random design of three replications. the treatments consisted of mesa at five rates (0, 8, 16, 24 and 32 µl/l) and storage time of five le...

to evaluate symbiotic effectiveness and salt tolerance of sinorhizobium meliloti strains, 50 rhizobial strains were isolated from root nodules of medicago sativa cultivated in tehran and zanjan fields. under n-free conditions, the symbiotic effectiveness of different sinorhizobium meliloti strains of bami cultivar were evaluated under greenhouse conditions using 50 sinorhizobium meliloti strain...

a p p r e h e n d s b u t d o e s n o t a p p r e h e n d t h i s s h a p e i n a w a y t h a t i s c o m p l e t e l y i n d e p e n d e n t f r o m m a t e r i a l c o n d i t i o n s . T h e p r o c e s s o f a b s t r a c t i o n i n i n c o m p l e t e s i n c e t h e c a t o n l y k n o w s t h i s s h a p e a s i t c h a r a c t e r i z e s a p a r t i c u l a r o b j e c t a n d n o t i...