The recent development by Craig (l-3) of an all-glass machine for liquidliquid counter-current fractionation makes possible the application of his method to the separation of porphyrins which cannot readily be separated by the sensitive Willstatter “HCl number” method. In this paper we have studied the application of the Craig method to the separation of a mixture of three known porphyrins, usi...

The principles of statistical mechanics relevant to atomistic computer simulation are reviewed. This is followed by a review of algorithms for generating statistical ensembles. An alternative method for statistical sampling of the isothermal-isobaric ensemble is formulated, based on Langevin dynamics in non-Hamiltonian systems. This is successfully tested on the Lennard-Jones system, and with b...

The thermoreversible gelation of methylcellulose in aqueous solution has been studied by static and dynamic light scattering (DLS), small-angle neutron scattering (SANS), and rheology. At 20 °C, dilute solution light scattering establishes the molecular weight, second virial coefficient, radius of gyration, and hydrodynamic radius of the polymer. Semidilute solutions exhibit two relaxation mode...

The first identification of a sterol in Chlorella was by Klosty and Bergmann (5) in 1952 when they isolated ergosterol from Chlorella pyrenoidosa. More recently, Otsuka (6) identified ergosterol and a A5 sterol in Chlorella ellipsoidea. Ergosterol was the principal component of the mixture. Recent work in this laboratory has been centered about the identification of sterols from other species o...

one of the most important issues in the plant layout design especially in mass production organizations with high inter-plant logistics is‘material flow and inter-plant traffic analysis and its effects on the production capabilities or pauses in production lines. in this paper the inter-plant traffic analysis issue on the basis of single channel queue model (m/m/1) is analyzed in a carmaker c...

in this paper, a viscous flow simulation is presented using the lattice boltzmann equation (lbe). a finite volume approach is adapted to discretize the lbe on a cell-centered, arbitrary shaped, rectangular tessellation. the formulation includes upwind scheme and high order descretization schemes for the flux term and collision operator respectively. a consistent open and solid boundary treatmen...

abstract bottom rack intake is one of the most appropriate structures for diverting water in steep rivers. the problems of corrosion, deformity and clogging of the bottom racks in long term, inspires a new system of bottom intake in which a filled trench of porous media is replaced by the bottom racks. diversion of a specified amount of discharge through the porous media when void space in the ...

recently, e. m'{a}v{c}ajov'{a} and m. v{s}koviera proved that every bidirected eulerian graph which admits a nowhere zero flow, admits a nowhere zero $4$-flow. this result shows the validity of bouchet's nowhere zero conjecture for eulerian bidirected graphs. in this paper we prove the same theorem in a different terminology and with a short and simple proof. more precisely, we p...