Superconducting LINAC booster for the mumbai pelletron

We are in the process of constructing a superconducting linear accelerator (LINAC), to boost the energy of heavy ion beams from the 14UD Pelletron accelerator, at Tata Institute of Fundamental Research, Mumbai. The accelerating structures in the LINAC are quarter wave resonators (QWR) coated with lead which is superconducting at liquid helium temperature. With feasibility studies having been completed during the course of the 4th and 5th five-year plan periods, culminating with the demonstration of beam acceleration using one accelerating module, the construction of the LINAC is now under way.     

Synthesis, Spectral and Thermal Studies of o-vanillin Oxime Complexes of Zinc(II), Cadmium(II) and Mercury(II)

Zinc(II), cadmium(II) and mercury(II) complexes of o-vanillin oxime have been synthesized and characterized by different physicochemical techniques. All the complexes have been subjected to non-isothermal decomposition studies in nitrogen atmosphere using thermogravimetry. The kinetic parameters for the decomposition of these complexes were evaluated using different methods and comparatively better results were obtained by these different methods. It has also been found that the decomposition processes of all these complexes follow first order kinetics. This revised version was published online in July 2006 with corrections to the Cover Date.     

Spectral studies of iron(III) complexes of substituted thiosemicarbazones of 2-acetylpyridine

Summary Iron(III) complexes of four substituted thiosemicarbazones of 2-acetylpyridine of general. formula [FeL₂]ClO₄ (where L is a deprotonated ligand) have been synthesised and characterised by elemental analyses, magnetic susceptibility measurements in the polycrystalline state at room temperature, i.r. spectra, electronic spectra and e.s.r. spectra recorded in polycrystalline state, in methanol solution at room temperature and at 77 K. All the complexes are 1:1 electrolytes. The ligands coordinate via the pyridine nitrogen, imine nitrogen and thione sulphur. E.s.r. spectra and with magnetic studies suggest a spin-paired configuration for the iron(III) complexes.Author to whom all correspondence should be directed     

Complex compounds of thorium oxalate with ammonium oxalate

The system thorium oxalate-ammonium oxalate-water has been investigated by physico-chemical methods. A new procedure is adopted in preparing the solution for these studies by the mono-variation method. Data have been presented to prove the existence of two complexes in solution from measurements of electrical resistance, pH and relative viscosity.     

Wrap-around partitioning for block bidiagonal linear systems

A stable vector algorithm for the solution of block diagonallinear systems is obtained by a permutation of the unknownscalled wrap-around partitioning combined with standard QR factorization.Wrap-around partitioning uses blocking and selects the unknownsin the blocks in turns. After a suitable orthogonal eliminationstep one ends up with a reduced system which is again blockbidiagonal and so wrap-around partitioning can be applied again.Using a simple model for vectorization overhead it is shownthat small block sizes give best performance. The minimal blocksize 2, which corresponds to cyclic reduction, is suboptimaldue to memory bank conflicts.     

An electrostatic charge state selector for ion-atom collisions: Design, spectral line-shapes and performance

An electrostatic charge state selector has been constructed for charge transfer studies in ion atom collisions. Its design and performance have been discussed illustrating with examples of some data taken using heavy ion beams from the pelletron accelerator. Expressions for the determination of charge state fractions from the observed charge spectrum in voltage scanning mode of operation and also the line shapes have been discussed analytically in detail.     

Absolute Intensities of the 10-µm Bands of (16)O(3)

Two hundred ninety experimental absolute intensities of nu(1) and nu(3) transitions of ozone have been measured, with good accuracy (<2%). They are used to derive the transition-moment parameters for these bands. The agreement between our observed and calculated line intensities is satisfactory. This work shows that the intensities of these two bands are on average 4% smaller than those used in the literature. In addition, 20 intensities of the nu(2) + nu(3) - nu(2) band confirm this value. Also, 42 line intensities of the 2nu(1)-nu(3) band are reported. Copyright 2001 Academic Press.     

Spectral studies of copper(II) complexes of tridentate acylhydrazone ligands with heterocyclic compounds as coligands: X-ray crystal structure of one acylhydrazone copper(II) complex

Six copper(II) complexes of 2-hydroxy-4-methoxybenzaldehyde nicotinoylhydrazone (H2hmbn), 2-hydroxy-4-methoxyacetophenone nicotinoylhydrazone (H2hman), 2-hydroxy-4-methoxybenzaldehyde benzoylhydrazone (H2hmbb) and 2-hydroxy-4-methoxyacetophenone benzoylhydrazone (H2hmab) have been synthesized. The complexes viz. [Cu(hmbn)](2)·2H(2)O (1), [Cu(hman)](2) (2), [Cu(hmbb)](2)·2H(2)O (3), [Cu(hmbb)phen]·1(1/2)H2O (4), [Cu(hmbb)(bipy)·H2O] (5) and [Cu(hmab)phen] (6) were characterized by different physicochemical techniques. The crystal structure of [Cu(hman)phen] is obtained and it has a distorted square pyramidal geometry with π-π stacking interactions and significant C-H π interactions.     

Synthesis and characterization of Mo(VI) complexes derived from ONO donor acylhydrazones

Four new dioxomolybdenum(VI) complexes were prepared using different acylhydrazones. Hydrazones used for complexation were derived from 2-hydroxy-4-methoxybenzaldehyde, 2-hydroxy-4-methoxyacetophenone, benzhydrazide and nicotinoyl hydrazide. The complexes were characterized by various spectroscopic techniques, thermal and elemental analyses. The (1)H NMR and IR spectral data indicate tridentate nature of the ligands through enolization. IR spectra provide information about the dimeric nature of the complexes. The thermal analyses of the complexes showed the presence of lattice water in some of the complexes.