vegetation is known to increase hillslope stability by reinforcing soil shear resistance. this reinforcement depends on the density and tensile strength of the root systems. this paper presents the results of research carried out in order to evaluate the biotechnical characteristics of the root system of parrotia persica. the profile trenching methods was used to obtaining root area ratio (rar)...

this study aimed to investigate morphological changes of capparis deciduas and c. spinosa and their effects on nebkha formation. in order to examine the morphological changes of these plants, nine c. spinosa nebkhas of varying ages were randomly selected and size and number of adventitious roots, number of shoot and buds were counted. results showed that the dead and green parts of c. spinosa i...

in order to evaluate some agronomical management on weed control in sugar beet this experiment was conducted at safi-abad agr.res.center, dezful in 2002 and 2004. tow planting dates, september 16 and october 12 and five cultivator applications, one and two time application at 4-6 and 6-8 leaf stages, respectively and once plus hand hoeing, weedy and weed free checks arranged in split plot desig...

The Liouville function is defined by λ(n) := (−1)Ω(n) where Ω(n) is the number of prime divisors of n counting multiplicity. Let ζm := e2πi/m be a primitive m–th root of unity. As a generalization of Liouville’s function, we study the functions λm,k(n) := ζ kΩ(n) m . Using properties of these functions, we give a weak equidistribution result for Ω(n) among residue classes. More formally, we sho...

Let p be a prime number and r ≥ 1 an integer. We compute the essential dimension of Z/pZ over fields of characteristic not p, containing the p-th roots of unity (theorem 3.1). In particular, we have edQ(Z/8Z) = 4, a result which was conjectured by Buhler and Reichstein in 1995 (unpublished).