We simulate species-area curves (SACs) using a spatially explicit neutral model. These display three distinct phases with the central phase being well approximated by a "power law" where species richness (S) is related to area (A) by S = cA(z). If seeds are normally distributed in space about their parent, the power law phase of the SAC is unrealistically narrow, and implausibly large speciatio...

We investigate Bak-Sneppen coevolution models on scale-free networks with various degree exponents gamma including random networks. For gamma>3 , the critical fitness value f(c) approaches a nonzero finite value in the limit N --> infinity, whereas f(c) approaches zero as 2(N) on the networks ...

before constitution revolution, advocacy in our country governed by islamic law and lawyers introduced as a free profession in means of that law. after that revolution the government promulgated some rules for its regulation as an official profession. by act of bar association independence, this profession declared independent. many lawyers after islamic revolution have been filtrated and by th...

Liquid paraffin can be used as a coolant fluid in electronic and cutting devices due to its suitable capabilities such as electrical insulating, high heat capacity, chemical, and thermal stability, and high boiling point. In this study, the dynamic viscosity of paraffin containing the alumina nanoparticles has been examined experimentally. The nanofluids with different composition of alumina (0...

Abstract The paper presents a comparison of the dissipation rate obtained from numerical differentiation time-resolved velocity, analog hot-wire signal, integration velocity derivative spectra spectra, and application power decay law. Hot-wire measurements downstream an active-grid provide with Taylor Reynolds number in range 200–470, turbulence intensities 5.8–11%, nominal mean velocities 4, 6...

In this paper hemodynamic wall parameters which play an important role to diagnose arterial disease were studied and compared for three different rheology models (Newtonian, Power law and Quemada). Also because of the pulsatile behavior of blood flow the results were obtained for three Womersley numbers which represent the frequencies of the applied pulses. Results show that Quemada model alway...

Abstract A generalized q-Taylor’s formula in fractional q-calculus is established and used in deriving certain q-generating functions for the basic hypergeometric functions and basic Fox’s H-function. 2010 Mathematics Subject Classification: 33D45, 26A33 and 33D90.

The power spectrum, S, of horizontal transects of plankton abundance are often observed to have a power-law dependence on wavenumber, k, with exponent close to −2: S(k) ∝ k over a wide range of scales. I present power spectral analyses of aircraft lidar measurements of phytoplankton abundance from scales of 1 to 100 km. A power spectrum S(k) ∝ k is obtained. As a model for this observation, I c...

generally speaking, tax is deemed as a manifestation of the government's authority and plays a key role in procuring public revenues as the most critical factor. indeed, we might say that continuity of the governmental activities depend on receiving taxes. thus, taxes occupy a high rank of importance in most countries, especially iran and england. therefore, lots of powers and privileges h...