Nd:DPA

Abstract Hazardous effects of various amines, produced in the environment from the partial degradation of azo dyes and amino acids, adversely affect the quality of human life through water, soil and air pollution and therefore needed to be degraded. A number of such studies are already available in the literature, with or without the use of ultrasound, which have been summarized briefly. The sono-chemical degradation of amines and in the combination with a photocatalyst, TiC>2 has also been discussed. Similar such degradation studies for ethylamine (EA), aniline (A), diphenylamine (DPA) and naphthylamine (NA) in the presence of ultrasound, Ti02 and rare earths (REs) La, Pr, Nd, Sm and Gd, in aqueous solutions at 20 kHz and 250 W power have been carried out and reported, to examine the combinatorial efficacy of ultrasound in the presence of a photocatalyst and rare earth ions with reactive f-electrons. 

In this formula, Nd is the average number of atomic displacements per a-decay event D = accumulated a-dose M = molar mass of the compound Nf = number of atoms in the compound and Na — Avogadro s number. The value of V,j is often assumed to be 1500, but computer codes can be used to estimate Nd and also to recalculate irradiation doses from heavy ions to dpa values (Ziegler et al. 1985). 

A commonly used measure of irradiation damage is displacements per atom (dpa). A unit of 1 dpa means that on the average, every atom in the irradiated volume has been displaced once from its equilibrium lattice site. The approximated dpa in the implanted region is given by equation 16 where 0 (ions/cm2) is the dose, and (Nd(E)) is the damage function given by equation 14. 

A simple approximation for dpa(.r) per unit dose can be made by assuming that Nd(x), the number of displacements per unit volume at a depth x, can be expressed by a modified Kinchin-Pease expression of the form... 

Substitution of the 4-position of the pyridine ring of dpa with OH or Cl has been achieved and the resulting Nd complexes formed with these derivatives showed better luminescence properties than the corresponding dpa complexes (Curry et al., 2005). 

Scheme Presumed reaction mechanisms (centres) of primary fission in the initiation process of the Nd T-bis(2,4,6-trinitrophenyl)3,5-dinitropyridine-2,6-diamine (PYX) molecule (taken from [165,183]) here Pi- is 2,4,6-trinitrophenyl whose break away (a secondary process) as a radical and subsequent reaction with other fragments of the PYX molecule gives DPA (see Scheme 9)...

Model calculations for intensity parameters have been reported for a series of Nd ", Ho complexes (E.M. Stephens et al. 1984) and for Er complexes (Devlin et al. 1987b) with trigonal symmetry. The ligands in the complexes are oxydiacetate (ODA), dipicolinate (DPA), iminodiacetate (IDA) and (methylimino)diacetate (MIDA). In addition, chelidonate (CDO) and chelidamate (CDA) complexes were studied for Er ". The calculations take into account the static-coupling [SC] and dynamic-coupling [DC] mechanisms as well as contributions arising from interferences between transition... 

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