projected global climate change may have a major influence on crop yield. the likely effects of climate change caused by increasing atmospheric carbon dioxide levels on rice yield in iran were evaluated using a mechanistic growth model for rice, gsac-rice, running under a climate change scenario predicted for a doubled-co2 (2xco2) atmosphere by the geophysical fluid dynamics laboratory (gfd...

the need for more comparisons among models is widely recognized. this study aimed to compare three different modelling approaches for their capability to simulate and predict trends and patterns of winter wheat yield in western germany. the three modelling approaches included an empirical model, a process-based model (lintul2), and a metamodel derived from the process-based model. the models ou...

land-use change affects a number natural processes such as soil erosion, sedimentation, flooding and destruction of soil physical and chemical properties. this change of ecosystem causes the degradation of soil quality which eventually leads to a severe decrease in soil fertility. therefore, various aspects of land-use change should be taken into account in national major decision makings. this...

passive solar systems such as solar chimneys need solar radiation in order to work. therefore, they cannot present stable natural ventilation when solar energy vanishes: to have a more robust and stable condition, solar energy should be stored during the day and released back during the night. phase change materials can save additional thermal energy during the day and release it during the nig...

A Bayesian analysis is used to detect a change-point in a sequence of independent random variables from exponential distributions. In This paper, we try to estimate change point which occurs in any sequence of independent exponential observations. The Bayes estimators are derived for change point, the rate of exponential distribution before shift and the rate of exponential distribution after s...

in this study, we have theoretically investigated the effect of electron stopper layer on internal temperature distribution of high performance vertical cavity surface-emitting laser emitting at 1305 nm.  simulation software pics3d, which self-consistently combines the 3d simulation of carrier transport, self-heating, gain computation and wave-guiding, was used. simulation results show that cha...

abstract development and evaluation of mitigation strategies are very crucial to manage climate change risk. research objectives of this study were (1) to quantify the response of maize grain yield to potential impacts of climate change and (2) to investigate the effectiveness of changing sowing date of maize as a mitigation option for khorasan province which is located in northeast of iran. tw...