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 ...

a semi-empirical mathematical model for predicting physical part of ignition delay period in the combustion of direct - injection diesel engines with swirl is developed . this model based on a single droplet evaporation model . the governing equations , namely , equations of droplet motion , heat and mass transfer were solved simultaneously using a rung-kutta step by step unmerical method . the...

in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...

126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...

چکیده روش های متعددی برای برآورد رواناب حاصل از بارش در حوضه های آبریز وجود دارد. یکی از این روش ها استفاده از مدل های هیدرولوژیکی است. با استفاده از مدل های هیدرولوژیکی و شبیه سازی فرآیندهای هیدرولوژیکی می توان با صرف کمترین زمان و هزینه، رواناب و مولفه های دیگر چرخ? هیدرولوژیکی را برآورد کرد. از آنجا که در حوضه های آبریز اندازه گیری تمام کمیت های مورد نیاز برای تحلیل رواناب ممکن نیست، انتخاب...

attempts have been made to study the thermodynamic behavior of 1,3 butadiene purification columns with the aim of retrofitting those columns to more energy efficient separation schemes. 1,3 butadiene is purified in two columns in series through being separated from methyl acetylene and 1,2 butadiene in the first and second column respectively. comparisons have been made among different therm...

the purpose of this study is to investigate the relationships between teachers’ immediacy behaviors and iranian students’ willingness to talk in english classes. analysis of the results from willingness to talk scale represents a relatively high level of willingness to talk in english classrooms among iranian language learners. the total mean score of students’ willingness to talk was 66.3 ou...

run-out-table (rot) is located between last finishing stand and down coiler in a hot strip mill. as the hot steel strip passes from rot, water jets impact on it from top and bottom and strip temperature decreases approximately from 800-950 °c to 500-750°c. the temperature history that strip experience while passing through rot affects significantly the metallurgical and mechanical properties, s...

the west of esfahan province, iran, is one of the most important agricultural areas throughout the country due to the climate variability and life-giving water of zayanderood river. rice is one of the major and economic crops in this area. the most important climatic elements in agricultural activities which should be considered include temperature, relative humidity, precipitation and wind. so...

the purpose of this study was to examine the status of supervision on departments’ heads at ferdowsi university of mashhad (fum) and realize some applied themes to provide a fit model for supervising departments’ heads in fum. the method was case study under a research category aimed for applied one. using purposive sampling, interviews were conducted with top fum managers, head departments, an...