Interrelationship of the baric index for the normal burning velocity of gas—Air mixtures and the kinetics of trimolecular reactions in a flame front

Through numerical simulation of flame propagation through a methane- and hydrogen-air mixture, with consideration given to the transfer and chemical reactions, we have investigated the relationship between the kinetics of trimolecular reactions and the baric index of the normal burning velocity. It has been demonstrated that the lower the constants of the trimolecular reaction rates, the higher the magnitude of the baric index. In the case of methane the baric index, although it grows, it nevertheless remains negative, while in the case of hydrogen this index changes sign.Balashikha. Translated from Fizika Goreniya i Vzryva, No. 2, pp. 46–49, March–April, 1991.     

Modification of leather properties by grafting. I. Effect of monomer chain on the physico‐mechanical properties of grafted leather

Although leather has a number of desirable properties such as thermal stability and fire retardancey, in addition to high toughness, it has a few drawbacks such as weight, high water absorption, poor soil and rot resistance, and nonuniformity. If these defects are overcome, leather's usefulness would be further enhanced and its competitive position with respect to synthetics would increase. This study reports the physical and mechanical properties of buffalo leather after chemical graft copolymerization with ethyl acrylate, butyl acrylate, and 2‐ethyl hexyl acrylate using benzoyl peroxide as an initiator. The optimum conditions for grafting (e.g., monomer and initiator concentrations, temperature and time of grafting, and solvent leather ratio) were extensively investigated. The study achieved outstanding properties for buffalo leather in reduction of water uptake after grafting, especially on using 2‐ethyl hexyl acrylate and butyl acrylate monomers. FT‐IR and solid ¹³C‐NMR for leather before and after grafting confirmed the grafting process.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1478–1483, 2003     

Liquid-phase stereoselective thymol hydrogenation over supported nickel catalysts

The stereoselective hydrogenation of thymol was studied in liquid phase over several nickel catalysts, modified by coimpregnation of inorganic compounds containing chlorine. The total activity of all catalysts studied was decreased and was on the same order of magnitude, indicating that chlorine even after reduction remains on the surface and is responsible for the poisoning effects. Such blocking of accessible sites results in similar reaction rates for the catalysts studied. Selectivity and stereoselectivity to menthols and menthones changed significantly. The modifiers could influence the rate of keto-enol transformations, which is thought to be the key selectivity and stereoselectivity governing step.     

Potentiostatic step experiments on pasted Pb-Sb and Pb-Sn-Ca electrodes

A range of cyclic electrochemical experiments have been carried out on electrodes of porous PbO₂ supported on a number of Pb-Sb and Pb-Sn-Ca alloys using micro-computer controlled potentiostatic stepping techniques. The results show that, in certain cases, the differences in electrochemical behaviour of the PbO₂ can be interpreted as being due to the effect of the support alloy.     

The anodic behaviour of zinc in KOH solution. V: Galvanostatic polarization with an interruption

Galvanostatic polarization experiments, in which the current flow is interrupted and re-established, show that the process of passivation is controlled by the transport of mass in the solution phase.Part IV: M. J. Brook and N. A. Hampson,Electrochim Acta 15 (1970) 1749.     

The differential capacitance of solid tantalum in some aqueous solutions

The differential capacitance of tantalum has been measured in a number of aqueous electrolyte solutions. The metal is generally covered with an oxide layer in solutions of simple inorganic anions and the electrode capacitance is 5–10 F cm^–2. In solutions of oxalate anions the electrode capacitance is much higher and corresponds to that expected for a clean metal in contact with an aqueous solution.     

Interactive image processing in research

The objective of the work described here was to build an interactive and multi-purpose image processing system and to use that system to solve practical problems. The system was built and it was demonstrated that it could be used to measure the size of gas bubbles in a gas---liquid reaction system. Photographs of gas bubbles were available from high-speed schlieren motion picture studies and image processing is a feasible way to make large numbers of measurements of bubble size quickly and accurately.