In still fluid, many phytoplankton swim in helical paths with an average upwards motion. A new mechanistic model for gravitactic algae subject to an intrinsic torque is developed here, based on Heterosigma akashiwo, which results in upwards helical trajectories in still fluid. The resultant upwards swimming speed is calculated as a function of the gravitactic and intrinsic torques. Helical swim...

Tree fern, an agricultural by-product, was used for the sorptive removal of copper ions from aqueous solution. The experimental data was analysed by Langmuir, Freundlich and Redlich-Peterson isotherms. The equilibrium sorption capacity of copper ions was determined from the Langmuir equation and found to be 11.7 mg/g. A batch sorption model, based on the assumption of the pseudo-second-order me...

Methylene blue adsorption on Sargassum muticum, an invasive macroalga in Europe, has been investigated using visible absorption spectroscopy. Different pre-treatments, protonation and chemical cross-linking with CaCl2 or H2CO, have been tested in order to improve the stability as well as the adsorption capacity of the algal biomass. The equilibrium binding has been described in terms of Langmui...

The sorption of lead ion onto palm kernel fiber was studied by performing batch kinetic sorption experiments. The batch sorption model, based on a pseudo-second-order mechanism, was applied to predict the rate constant of sorption, the equilibrium capacity and the initial sorption rate with the effects of the initial solution pH and fiber dose. Equilibrium concentrations were evaluated with the...

The idea that enzyme catalysis involves special factors such as coherent fluctuations, quantum mechanical tunnelling and non-equilibrium solvation (NES) effects has gained popularity in recent years. It has also been suggested that transition state theory (TST) cannot be used in studies of enzyme catalysis. The present work uses reliable state of the art simulation approaches to examine the abo...

Quantum time correlation functions obtained from the linear response theory are defined in terms of a scalar product involving the Kubo transform. This form of the scalar product also insures that the nonequilibrium average of the random force fluctuations corresponding to an observable vanish so that the macroscopic law is obtained on long distance and time scales and the Onsager regression hy...

The small size (58 residues) and simple structure of the B domain of staphylococcal protein A (BdpA) have led to this domain being a paradigm for theoretical studies of folding. Experimental studies of the folding of BdpA have been limited by the rapidity of its folding kinetics. We report the folding kinetics of a fluorescent mutant of BdpA (G29A F13W), named F13W*, using nanosecond laser-indu...

The ε-well-supported Nash equilibrium is a strong notion of approximation of a Nash equilibrium, where no player has an incentive greater than ε to deviate from any of the pure strategies that she uses in her mixed strategy. The smallest constant ε currently known for which there is a polynomial-time algorithm that computes an ε-well-supported Nash equilibrium in bimatrix games is slightly belo...