Pearson, William

Submitted by KARL H. PEARSON, WILLIAM R. HOWELL, JR.,f PAUL E. REINBOLD,f and STANLEY KIRSCHNER ... 

Edwin M Kaiser William G Kenyon R A Klein C Konig A Paul Krapcho Stephen J Kuhn William C Kuryla Peter A Leermakers Robert L Letsinger Guy S Lougheed B J Magerlein R J L Martin John G Moefatt D Nasipuri George A Olah D E Pearson R J Petersen G Ploss J Posner A Rieche... 

For substituted anilines (Thompson and Williams, 1977) and for 1-naphthylamine and a series of derivatives thereof (Castro et al., 1986a), k2 and the ratio Ar 2/Ar3 have been determined for nucleophilic catalysis with Cl-, Br-, SCN-, and SC(NH2)2. The values of k2 correspond fairly well to those found for the diazotization of aniline, but those of Ar 2/Ar3 increase markedly in the above sequence (Table 3-1). As k3 is expected to be independent of the presence of Cl- or Br- and to show little dependence on that of SCN- or thiourea, the increase in k 2/k3 for this series must be due mainly to 2. Indeed, the value of log(Ar 2/Ar3) shows a linear correlation with Pearson s nucleophilicity parameter n (Pearson et al., 1968). This parameter is based on nucleophilic substitution of iodine (as I-) in methyl iodide by various nucleophiles. The three investigations on nucleophilic catalysis of diazotization demonstrate that Pearson s criteria for bimolecular nucleophilic substitution at sp3 carbon atoms are also applicable to substitution at nitrogen atoms. 

L. G. Leal, Challenges and Opportunities in Fluid Mechanics and Transport Phenomena William B. Russel, Fluid Mechanics and Transport Research in Chemical Engineering J. R. A. Pearson, Fluid Mechanics and Transport Phenomena... 

Strength develops rapidly and after 24 hours in water (37 °C) can reach 225 MPa (compressive) and 39 MPa (flexural) (Williams Billington, 1989 Pearson Atkinson, 1991 Pearson, 1991). Compressive modulus reaches 9 to 18 GPa after 24 hours (Paddon Wilson, 1976 Wilson, Paddon Crisp, 1979). 

Very recently, Williams, Billington Pearson (1992) have examined the effect of reinforcement by silver or silver-tin alloy on the mechanical properties of three glass-ionomer cements. Measurements of compressive, flexural, tensile (measured by the diametral compressive procedure) and shell strength are given in Table 5.17. These results show that the effect of reinforcement varies from cement to cement but, in general, increases it. 

Table 5.17. Effect of reinforcement on various strength properties of three glass polyalkenoate cements Williams, Billington Pearson, 1992)...

Williams, J. A., Billington, R. W. Pearson, G. J. (1992). The comparative strengths of commercial glass-ionomer cements with and without metal additions. British Dental Journal, 172, 279-82. 

Setchell, Teo Kuhn (1985) observed that glass-ionomer cements prepared from poly(acrylic acid) were more resistant to erosion than such cements prepared from maleic acid copolymers. This has been confirmed by Wilson et al. (1986) and by Billington (1986), even when, as in the latter case, the same glass was used in both cements. The method has been reviewed recently by Billington, Williams Pearson (1992). 

Mystagogus, Cleidophorus. Mercury s caducean rod or, the great and wonderful office of the universal mercury, or God s vicegerent (sic ), displayed. Wherein is shewn his nativity, life, death, renovation and exaltation to an immutable state to which is added a general epistle discovering the mysterious fire of Pontanus. By. The second edition. 2nd ed ed. 1702 reprint, London Printed by William Pearson, for Thomas Ballard, at the Rising Sun in Little Britain, 1704. 76, 32p. 

R.W. Billington, P.C. Fladley, J.A. Williams, G.J. Pearson, Kinetics of fluoride release from zinc oxide-based cements. Biomaterials 22 (2000) 2507-2513. 

J.A. Williams, R.W. Billington, G.J. Pearson, Comparison of ion release from a glass ionomer cement as a function of the method of incorporation of added ions. Biomaterials 20 (1999) 589-594. 

The Chemistry of Heterocyclic Compounds, Volume 59 Synthetic Applications of 1,3-Dipolar Cycloaddition Chemistry Toward Heterocycles arul Natural Products. Edited by Albert Padwa and William H. Pearson. 

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