Sedimentation velocity analytical ultracentrifugation is an important tool in the characterization of macromolecules and nanoparticles in solution. The sedimentation coefficient distribution c(s) of Lamm equation solutions is based on the approximation of a single, weight-average frictional coefficient of all particles, determined from the experimental data, which scales the diffusion coefficie...

soils around mining sites play a significant role in the transport and control of heavy metals in the environment. therefore, understanding the adsorption properties of soil is essential in solving pollution problems. the objective of this paper was to study zn(ii) adsorption onto sarcheshmeh copper mine soils. the adsorption isotherms of zn(ii) were studied. the langmuir isotherm indicated an ...

the feasibility of extractive reaction of methacrylic acid from aqueous solution using a quaternary amine, tri–octyl methyl ammonium chloride (tomac) as an extractant, was studied. the diluents chosen in the present work belong to different chemical classes, n–butyl acetate, carbon tetrachloride, isoamyl alcohol, methyl isobutyl ketone, and toluene. the effect of initial acid concentration in t...

In this paper, we present a simple model of scale-free networks that incorporates both preferential & random attachment and anti-preferential & random deletion at each time step. We derive the degree distribution analytically and show that it follows a power law with the degree exponent in the range of (2,∞). We also find a way to derive an expression of the clustering coefficient for growing n...

We propose an extended local-world evolving network model including a triad formation step. In the process of network evolution, random fluctuation in the number of new edges is involved. We derive analytical expressions for degree distribution, clustering coefficient and average path length. Our model can unify the generic properties of real-life networks: scale-free degree distribution, high ...