The exceptional stereoselectivity of coordination (RS isomer favored) of the prochiral olefinic alcohol 2-methyl-3-buten-2-ol in cis(N,olefin)-chloro(2-methyl-3-buten-2-ol)(sarcosinato)platinum(II), 1, prompted this investigation of the effect of olefin structure on the equilibrium constant for platinum binding (K d) and on the stereoselectivity of coordination, as measured by K i = [RR]/[RS], for 32 other monosubstituted ethylenes with the same chiral template. The only other olefins which show significant preference for the RS diastereomer (K i < 0.5) contain hydrogen-bond acceptor atoms in close proximity to the N−H proton of the coordinated olefin which is cis to that nitrogen. Increasing the distance between the N−H proton and the proton acceptor atom by one C−C link has a dramatic effect on K i. Almost no correlation was found between K d and K i, but a significant correlation between the formation constant, K f, for formation of PtCl3(olefin)- species of 14 of the olefins and the 195Pt chemical shift suggested a way to separate electronic effects from steric and hydrogen-bonding effects on the relative stabilities of the mixed olefin−amino acid complexes. Deviations from a simple correlation between log K d and log K f are discussed in terms of this model, but a clean separation of electronic effects from other effects cannot be claimed.

Microfiltration performance has been analysed by evaluating the influence of three macro-compounds as a function of the cross-flow velocity (CFV), transmembrane pressure (TMP) and pore size of the membranes. Four mathematical models were evaluated to relate the permeate flow rate (J p) to the concentration of the macrocompounds in the retentate (C b) during filtration in concentration mode. Pectin has a greater impact than cellulose and lignin on the permeate flux (J p). The largest value of K 2 was found for pectin in the model 1 1 2 − = + ⋅ p b J K K C. The optimum operating conditions and pore size to reduce fouling of the membranes depend on the pore size to particle size ratio and the physicochemical interactions between the solute and membrane. The mathematical model is useful in the region where the permeate flow is nearly independent of pressure, the pore size and cross-flow velocity but is dependent on the diffusional phenomenon of mass transfer.

A rate process governing the transport and decay of a radioactive substance in a solidified waste and a surrounding fluid is simulated mathematically. The solidified radioactive waste is often buried underground or disposed of in the sea and is brought into contact with groundwater or sea water. A certain radioactive component distributed in the solidified waste dissolves in the water and then diffuses out of the slab to the surrounding fluid because of the concentration difference. The decay of the radioactive substance in both the slab and the surrounding fluid of the system is an irreversible first order rate process. The analytical expressions for the change of concentration of the radioactive substance are derived through the use of a Laplace transformation technique both as a function of time and position for the porous body and as a function of time for the surrounding fluid. The mathematical expressions are useful in predicting concentrations in the system as well as in determining the effective diffusivity and the decay coefficient of the radioactive substance.