Climate change is a phenomenon has been based on the available evidence from a very long time ago and now its existence is very probable. The speed and nature of climate parameters changes at the middle of twentieth century has been different and its quickness more than the before and its trend changed to some extent comparing to the past. Climate change issue now regarded as not only one of th...

the main purpose of this article is, showing similar fluctuation of temperature series and their consistency with what happened in the global level. in addition, it determines new estimates of regional seasonal and annual temperature trends over iran, after the detection of artificial and natural non homogenous points of 33 synoptic stations for the period of 1960 2010. the 22 stations with sho...

introduction the city population, in particular at the industrialized cities and centers of provinces, has increased dramatically in iran during recent decades. arak city is among of those industrialized cities as a centers of markazi province which has experienced a fast increase in population. this changes in population numbers tend to increase in consuming water resources as well as increasi...

1. The capacity to perform photosynthesis, given appropriate environmental conditions, is reflected by measurements of the maximum quantum yield of photosystem II ( F v / F m ). The seasonal course of F v / F m may help define the length of the annual photosynthetic period in temperate evergreen forests. 2. F v / F m was measured 31 times from September to May on six conifer species located alo...

Thermal modelling and optimal design of a solar absorption cooling system are presented, and hourly analysis is performed over the period of a year. Three design parameters are considered, then the Real Parameter Genetic Algorithm (RPGA) is applied to obtain the minimum total annual cost. The optimization results show that the solar cooling optimum configuration needs 1630 square meter collecto...