Using growing degree days (GDD) for expression of duration of plants’ developmental stages is preferred over calendar time. Therefore, determination of GDD and zoning of regions is very important for on time and correct agronomic practices and also for better land use. To determine the required GDD for developmental stages of spring safflower cultivars, the data obtained from planting-date ex...

Growth and grain yield of irrigated barley cultivars (Valfajr, Binam and Raihaneh) was investigated at 4 sowing dates (6, 22 Oct. and 14, 20 Nov.) in Karaj region. The effect of sowing date, genotype and their interaction on grain yield were statistically significant. Early and late sowing enhanced cold damage. However, the damage was more in late sowings. It was estimated that the optimum sowi...

terms of address as an important linguistics items provide valuable information about the interlocutors, their relationship and their circumstances. this study was done to investigate the change route of persian address terms in the two recent centuries including three historical periods of qajar, pahlavi and after the islamic revolution. data were extracted from a corpus consisting 24 novels w...

abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...

saluk mount is selected for devonian biostratigraphy. this area located at southwest of bojnurd. in this study three sections are selected and two sections, chahar-borj and tabar sections with a thickness of 650 m, which consist mainly of calcareous sediments was studied in detailed but third section, qelli section, with a thickness of about 450m which consist mainly of sandstone and evaporates...

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...