The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform

R G Sargent - One of the best experts on this subject based on the ideXlab platform.

W I Stephen - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of some as triazines and re evaluation of pdt and ferrozine as reagents for spectrophotometric determination of ruthenium
    Talanta, 1992
    Co-Authors: M.a. Islam, W I Stephen
    Abstract:

    Abstract A sensitive method for the spectrophotometric determination of ruthenium with the ferroinyielding as-triazines has been developed. This method has several advantages; complete reduction of ruthenium species to ruthenium(II) can be achieved by the Recommended Procedure, which shortens the colour development time, saves the unnecessary use of several-fold excess of the reagent and the molar absorptivity is increased significantly. A few of the new as-triazines together with the commercially available Ferene® have been evaluated as ruthenium(II) chromogens. 3-(2-Pyridyl)-5,6-diphenyl-as-triazine (PDT) and ferrozine, a sulphonated derivative of PDT, have been re-evaluated by the new method. It has been observed that the as-triazine acting as a bidentate ligand forms a tris-complex with ruthenium(II) similar to its reaction with iron(II).

Vito Bartocci - One of the best experts on this subject based on the ideXlab platform.

  • kinetic and equilibrium studies on mercury ii coproporphyrin i metal ion exchange reaction with cobalt ii and application to determination of trace mercury ii
    Talanta, 1998
    Co-Authors: Rita Giovannetti, Vito Bartocci
    Abstract:

    Abstract The reaction of 3,8,13,18-tetramethyl-21H,23H-porphine-2,7,12,17-tetrapropionic acid or coproporphyrin-I (CPI) with mercury(II) was studied spectrophotometrically, and kinetic and equilibrium constants were determined; the influence of temperature on the reaction rate was also studied. It was verified that mercury(II) accelerates the incorporation reaction of cobalt(II) into CPI; the kinetics and mechanism of this reaction at high alkaline pH were studied. Sensitive kinetic methods for the determination of mercury(II) at ppb levels have been established; the apparent molar absorbivity and Sandell's sensitivity for the Recommended Procedure, at 368 nm, and 400 s after the start of the reaction, were: 4.23×105 (l mol−1cm−1) and 0.474 (ng cm−2) (for A=0.001).

Shabbar Jaffry - One of the best experts on this subject based on the ideXlab platform.

  • Recreational benefits of coastal protection: a case study
    Marine Policy, 1999
    Co-Authors: David Whitmarsh, James Northen, Shabbar Jaffry
    Abstract:

    In the UK, cost-benefit analysis of coastal protection schemes that expect to receive grant assistance is required by H.M. Government. A Recommended Procedure for evaluating the recreational benefits of coastal protection is based on a variant of contingent valuation methodology (CVM), and involves the estimation of the gains and losses in the value of enjoyment by beach users associated with different project scenarios (including the option of allowing erosion to occur). The paper reports the results of a study which applies this approach to coastal protection at an important UK seaside resort. It focusses on the suitability of the value of enjoyment (VOE) elicitation method, and stresses the need to test the validity of the results from all such studies that apply this approach.

  • Recreational benefits of coastal protection: a case study
    Marine Policy, 1999
    Co-Authors: David Whitmarsh, James Northen, Shabbar Jaffry
    Abstract:

    In the UK, cost-benefit analysis of coastal protection schemes that expect to receive grant assistance is required by H.M. Government. A Recommended Procedure for evaluating the recreational benefits of coastal protection is based on a variant of contingent valuation methodology (CVM), and involves the estimation of the gains and losses in the value of enjoyment by beach users associated with different project scenarios (including the option of allowing erosion to occur). The paper reports the results of a study which applies this approach to coastal protection at an important UK seaside resort. It focusses on the suitability of the value of enjoyment (VOE) elicitation method, and stresses the need to test the validity of the results from all such studies that apply this approach.

M.a. Islam - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of some as triazines and re evaluation of pdt and ferrozine as reagents for spectrophotometric determination of ruthenium
    Talanta, 1992
    Co-Authors: M.a. Islam, W I Stephen
    Abstract:

    Abstract A sensitive method for the spectrophotometric determination of ruthenium with the ferroinyielding as-triazines has been developed. This method has several advantages; complete reduction of ruthenium species to ruthenium(II) can be achieved by the Recommended Procedure, which shortens the colour development time, saves the unnecessary use of several-fold excess of the reagent and the molar absorptivity is increased significantly. A few of the new as-triazines together with the commercially available Ferene® have been evaluated as ruthenium(II) chromogens. 3-(2-Pyridyl)-5,6-diphenyl-as-triazine (PDT) and ferrozine, a sulphonated derivative of PDT, have been re-evaluated by the new method. It has been observed that the as-triazine acting as a bidentate ligand forms a tris-complex with ruthenium(II) similar to its reaction with iron(II).