tetrahydrobenzo[b]pyran derivatives 1 were utilized for the synthesis of several new pyrano[2,3-d]pyrimidine derivatives 2. compound 2 was obtained in the presence of ac2o/h2so4 (as a catalyst) and was confirmed by spectroscopic data such as ir, 1h nmr and 13c nmr. ab initio calculation was carried out to study geometric optimization, thermodynamic parameters, aromaticity and dynamic process of...

a simple method has been developed for the preconcentration of lead (ii) based on the adsorption of its 1-(2-pyridyl azo)2-naphtol (pan) complex on aoctadecyl bonded silica cartridges. the influence of acidity, eluting agents, stability of the column, sample volume and interfering ions has been investigated in detail. the adsorbed complex could be eluted using environmentally benign hno34m and ...

religious tourism is one of the varieties of tourism that authorities in this filed , believe iran, due to its special cultural and religious capacities and geographical position , has an important role in developing religious tourism industry. one of the important factors that affects industry tourism, especially developing the religious one ,is the aerial transportation industry for the time ...

deficiency of water resources is one of the major challenges at the global scale and also in iran. the existence water resources of oceans and seas such as the caspian sea and persian gulf in the north and southern parts of iran respectively, can be considered as the alternative to dominate the future problem. this study is processed absorption of nacl based-on natural zeolite and perlite. in o...

this paper describes a methodology for the integration of well logs and a series of grid-based attributes extracted from interpreted seismic data for prediction of porosity distributions. the studied area is located in the southwest iran. before finding a relationship between the target logs and predicted logs from 3d seismic data, we have interpreted the 3d seismic data in the studied area. al...

a greenhouse experiment was carried out to evaluate the effects of salinity stress on growth and macroelements contents of two olive varieties under hydroponic conditions. in the research, one-year old saplings of two olive varieties, ‘zard’ and ‘mission’, were subjected to different salinity levels induced by nacl including 0, 4, 8, 12 and 16 dsm-1 for 5 months. based on the results, total dry...

in this research, moisture sorptions of sayer date were determined at 20, 30, 40 and 60°c, using the standard static gravimetric method developed by the european cooperation project cost 90. several mathematical models, namely gab, bet, iglesias & chirif and halsey were employed to fit the experimental data through non-linear regression. results indicate that equilibrium moisture content increa...

in this paper, the correlation between total ozone and upper air meteorological parameters such as heights of geopotential surfaces and temperatures for three stations of tehran, ankara and bet dagan located in the middle east, in cold period (jan, feb and march) of years of 2005, 2007 and 2008 has been investigated. data for upper air is taken from wyoming university and ozone data is from sat...

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...

in this research, temporal and spatial behavior of siberian high (sh) was studied at the level of 1000 h.pa. this study has been done using daily data of geo potential height at 12 gmt in ncep/ncar database with spatial resolution of 2.5ã—2.5 degree in a 55 years period including 20089 days from january, 1st, 1951(dey, 11th, 1329) to december, 31st,2005(dey, 10th,1384). at first, the mean geo p...