The exponentiated generalized inverse Gaussian distribution

The modeling and analysis of lifetime data is an important aspect of statistical work in a wide variety of scientific and technological fields. Good (1953) introduced a probability distribution which is commonly used in the analysis of lifetime data. For the first time, based on this distribution, we propose the so-called exponentiated generalized inverse Gaussian distribution, which extends the exponentiated standard gamma distribution (Nadarajah and Kotz, 2006). Various structural properties of the new distribution are derived, including expansions for its moments, moment generating function, moments of the order statistics, and so forth. We discuss maximum likelihood estimation of the model parameters. The usefulness of the new model is illustrated by means of a real data set. (c) 2010 Elsevier B.V. All rights reserved.

Organic additive-copper(II) complexes as plating precursors

Cu(II) ions previously coordinated with typical electroplating organic additives were investigated as an alternative source of metal for plating bath. The coordination complexes were isolated from reaction between CuSO(4) and organic additives as ligands (oxalate ion, ethylenediamine or imidazole). Deposits over 1010 steel were successfully obtained from electroplated baths using the complexes without any addition of free additives, at pH = 4.5 (H(2)SO(4)/Na(2)SO(4)). These deposits showed better morphologies than deposits obtained from CuSO(4) solution either in the absence or presence of oxalate ion as additive (40 mmol L(-1)), at pH = 4.5 (H(2)SO(4)/Na(2)SO(4))It is suggestive that the starting metal plating coordinated with additives influences the electrode position processes, providing deposits with corrosion potentials shifted over + 200 mV in 0.5 mol L(-1) NaCl (1 mV s(-1)). The resistance against corrosion is sensitive to the type of additive-complex used as precursor. The complex with ethylenediamine presented the best deposit results with the lowest pitting potential (-0.27 V vs 3.0 mol L(-1) CE). It was concluded that the addition of free additives to the electrodeposition baths is not necessary when working with previously coordinated additives. Thus, the complexes generated in ex-situ are good alternatives as plating precursors for electrodeposition bath. (C) 2009 Elsevier B.V. All rights reserved.