A young potted oak (Quercus robur L.) tree was subjected to drought by interrupting the water supply for 9 days. The tree was placed in a growth chamber in which daily patterns of temperature and radiation were constant. The effects of drought on the water and carbon status of the stem were examined by measuring stem sap flow rate, stem water potential, stem diameter variations, stem CO(2) effl...

China's water resources are under increasing pressure from socioeconomic development, diet shifts, and climate change. Agriculture still concentrates most of the national water withdrawal. Moreover, a spatial mismatch in water and arable land availability--with abundant agricultural land and little water resources in the north--increases water scarcity and results in virtual water transfers fro...

Two-phase flow regimes are affected by conduit position, alignment, geometry, flow direction, physical characteristics, and flow rate of each phase as well as the heat flux toward the boundaries. Due to the importance of two-phase flow, numerous regimes have been identified. The first step in studying micro-bubble formation inside a venturi tube is to recognize the type of flow regimes. In this...

Plant aquaporins play an important role in water uptake and movement-an aquaporin that opens and closes a gate that regulates water movement in and out of cells. Some plant aquaporins also play an important role in response to water stress. Since their discovery, advancing knowledge of their structures and properties led to an understanding of the basic features of the water transport mechanism...

abstract for investigating the effect of bed form in alluvial channels on the amount of bed load transport, a set of experiments was carried out in a tilting flume under unsteady flow conditions (hydrograph). the produced hydrographs were in triangular form with a maximum discharge of 30 to 45 lit/s/m. three size of sediment particles were used with equal to 1.5, 2.1 and 3.0mm, clear water with...

water obtained from any source may contain impurities induced by erosion, dissolved minerals, dissolved gases and material produced from organic matter decomposing. if the amount of these substances exceed a certain limit, not only the water would not be potable, but the water containing the material will not be suitable to be used in most applications, or at least before treatment cannot be ap...

this article aims at designing the mathematical model for aras dam reservoir in time operation with missions of agriculture needs safeguarding, water electric energy production and torrent controls. reservoir system relations determinate and these relations at framework of are determined and stochastic dynamic programming are calculated executive results of this model are presentation of guides...