in order to investigate of the effects of water stress on seed yield and gas exchange and to evaluate the relationship between source and sink in sunflower azargol variety, a split-plot factorial field experiment was conducted in 2008. in this experiment, water stress (no irrigation from 30 days after sowing till ripening) and irrigation (irrigation at -3 bar soil water potential) were consider...

To maintain iron homeostasis within the cell, bacteria have evolved various types of iron acquisition systems. Ferric iron (Fe(3+)) is the dominant species in an oxygenated environment, while ferrous iron (Fe(2+)) is more abundant under anaerobic conditions or at low pH. For organisms that must combat oxygen limitation for their everyday survival, pathways for the uptake of ferrous iron are ess...

the topological index of a graph g is a numeric quantity related to g which is invariant underautomorphisms of g. the vertex pi polynomial is defined as piv (g)  euv nu (e)  nv (e).then omega polynomial (g,x) for counting qoc strips in g is defined as (g,x) =cm(g,c)xc with m(g,c) being the number of strips of length c. in this paper, a new infiniteclass of fullerenes is constructed. the ...

Sink location is considered as a basic service in geographic routing in wireless sensor networks. Obtaining the location of sink node by source node using an efficient method with low complexity has always been a challenging issue in research. In this paper, a sink location algorithm based on Fano plane is proposed. The research challenge is how to ensure the intersection of two SLQ (Location Q...

This study numerically investigated heat transfer and fluid flow characteristics in a novel cylindrical heat sink with helical minichannels for the laminar flow of fluid with temperature-dependent properties. A finite volume method was employed to obtain the solution of governing equations. The effects of helical angle, channel aspect ratio, and Reynolds number, which were regarded as main para...

introduction: iron is found in different forms in the soil. in the primary minerals, iron is found as fe3+ or fe2+ which converted to fe2+ and released in unsuitable reduction conditions. minerals such as sulfide or chlorine and bicarbonate can affect and change the different forms soil fe. feas these elements are abundance in groundwater or soil, they are capable to react chemically with fe an...

A major challenge limiting the practical applications of nanomaterials is that the activities of nanostructures (NSs) increase with reduced size, often sacrificing their stability in the chemical environment. Under oxidative conditions, NSs with smaller sizes and higher defect densities are commonly expected to oxidize more easily, since high-concentration defects can facilitate oxidation by en...

Mammals exhibit daily anticipatory activity to cycles of food availability. Studies on such food anticipatory activity (FAA) have been conducted mainly in nocturnal rodents. They have identified FAA as the behavioral output of a food entrained oscillator (FEO), separate of the known light entrained oscillator (LEO) located in the suprachiasmatic nucleus (SCN) of hypothalamus. Here we briefly re...