The effect of sulfanilamide on the electrocrystallization of copper on a single crystal copper (110) plane

The presence of small quantities of sulfanilamide in a highly purified acidic CuSO4 electroplating bath alters the growth habit of Cu on a single-​crystal Cu(110) plane. At a given c.d. a transition from a ridge type of growth to broken ridgesand then to polycryst. growth was obsd. with increasing sulfanilamide concn. andthis mechanism was discussed using η vs. log i curves. These effects were attributed to complex formation, decomplexation and the adsorption of sulfanilamide

The structure of dark matter halos in hierarchical clustering theories

During hierarchical clustering, smaller masses generally collapse earlier than larger masses and so are denser on the average. The core of a small mass halo could be dense enough to resist disruption and survive undigested, when it is incorporated into a bigger object. We explore the possibility that a nested sequence of undigested cores in the center of the halo, which have survived the hierarchical, inhomogeneous collapse to form larger and larger objects, determines the halo structure in the inner regions. For a flat universe with $P(k) \propto k^n$, scaling arguments then suggest that the core density profile is, $\rho \propto r^{-\alpha}$ with $\alpha = (9+3n)/(5+n)$. But whether such behaviour obtains depends on detailed dynamics. We first examine the dynamics using a fluid approach to the self-similar collapse solutions for the dark matter phase space density, including the effect of velocity dispersions. We highlight the importance of tangential velocity dispersions to obtain density profiles shallower than $1/r^2$ in the core regions. If tangential velocity dispersions in the core are constrained to be less than the radial dispersion, a cuspy core density profile shallower than 1/r cannot obtain, in self-similar collapse. We then briefly look at the profiles of the outer halos in low density cosmological models where the total halo mass is convergent. Finally, we analyze a suite of dark halo density and velocity dispersion profiles obtained in cosmological N-body simulations of models with n= 0, -1 and -2. We find that the core-density profiles of dark halos, show considerable scatter in their properties, but nevertheless do appear to reflect a memory of the initial power spectrum, with steeper initial spectra producing flatter core profiles. (Abridged)Comment: 31 pages, 7 figures, submitted to Ap

The effect of sulfanilamide on the electrodeposition of copper onto a single crystal copper (100) plane and a polycrystalline copper substrate

Studies were made of the electrodeposition of Cu onto a single-​crystal Cu(100) plane and onto a polycryst. Cu surface both in pure acidic CuSO4 soln. and in solns. contg. various concns. of sulfanilamide at various c. ds. the transition is from pyramids to truncated blocks to ridges and then to a polycryst. deposit. On a polycryst. substrate there is a change from large grains to very fine grains in the presence of sulfanilamide. These changes are explained with the help of complexation and adsorption theory

Electrodeposition of copper on a copper single-crystal (100) face and on a copper polycrystalline surface in the presence of sulphaguanidine

In the presence of sulphaguanidine a triangular pyramid growth form changes successively to a layer type of growth which transforms to ridges and then to a polycrystalline deposit on a (100) single-crystal copper substrate. On a polycrystalline copper surface the grain size of the deposit is affected markedly by sulphaguanidine. The change in the growth form and overpotential are explained with the help of IR and X-ray techniques. © 1979

Surface modified nano-zeolite used as carrier for slow release of sulphur

Surface modified nano-zeolite (SMNZ) was used as carrier to develop nano-zeolite based nano-sulphur fertilizer. A laboratory study on sulphur nano-fertilizer and conventional sulphur fertilizer were studied with percolation reactor system to evaluate the slow release of sulphur from both fertilizers in ambient temperature. SMNZ and sulphur nano-fertilizer were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Zeta Analyzer, Raman Spectroscopy, XRD and Scanning Electron Microscope (SEM). Raman spectroscopy confirmed the sulphur attachment at 480 cm-1 in the SMNZ. The FTIR spectra at 1030 cm-1 confirmed the sulphate attachments in the SMNZ spectrum. Zeta analyzer showed the surface charge of sulphur nano-fertilizer had (-) 52.6 mV. SEM imaged the sulphur loaded SMNZ in irregular flake like structure. A comparative study of the release of sulphate (SO4 2-) from fertilizer-loaded SMNZ and (NH4)2 SO4 fertilizers were performed using the percolation reactor. The results showed that the SO42- supply from fertilizer-loaded SMNZ was available even after 912 h of continuous percolation, whereas SO42- from (NH4)2 SO4 was exhausted within 384 h. These properties suggest that SMNZ has a great potential as the fertilizer carrier for slow release of SO42-

How are Forbush decreases related to interplanetary magnetic field enhancements ?

Aims. Forbush decrease (FD) is a transient decrease followed by a gradual recovery in the observed galactic cosmic ray intensity. We seek to understand the relationship between the FDs and near-Earth interplanetary magnetic field (IMF) enhancements associated with solar coronal mass ejections (CMEs). Methods. We use muon data at cutoff rigidities ranging from 14 to 24 GV from the GRAPES-3 tracking muon telescope to identify FD events. We select those FD events that have a reasonably clean profile, and magnitude > 0.25%. We use IMF data from ACE/WIND spacecrafts. We look for correlations between the FD profile and that of the one hour averaged IMF. We ask if the diffusion of high energy protons into the large scale magnetic field is the cause of the lag observed between the FD and the IMF. Results. The enhancement of the IMF associated with FDs occurs mainly in the shock-sheath region, and the turbulence level in the magnetic field is also enhanced in this region. The observed FD profiles look remarkably similar to the IMF enhancement profiles. The FDs typically lag the IMF enhancement by a few hours. The lag corresponds to the time taken by high energy protons to diffuse into the magnetic field enhancement via cross-field diffusion. Conclusions. Our findings show that high rigidity FDs associated with CMEs are caused primarily by the cumulative diffusion of protons across the magnetic field enhancement in the turbulent sheath region between the shock and the CME.Comment: accepted in A&

A Unified treatment of small and large- scale dynamos in helical turbulence

Helical turbulence is thought to provide the key to the generation of large-scale magnetic fields. Turbulence also generically leads to rapidly growing small-scale magnetic fields correlated on the turbulence scales. These two processes are usually studied separately. We give here a unified treatment of both processes, in the case of random fields, incorporating also a simple model non-linear drift. In the process we uncover an interesting plausible saturated state of the small-scale dynamo and a novel analogy between quantum mechanical (QM) tunneling and the generation of large scale fields. The steady state problem of the combined small/large scale dynamo, is mapped to a zero-energy, QM potential problem; but a potential which, for non-zero mean helicity, allows tunneling of bound states. A field generated by the small-scale dynamo, can 'tunnel' to produce large-scale correlations, which in steady state, correspond to a force-free 'mean' field.Comment: 4 pages, 1 figure, Physical Review Letters, in pres

Green processes in process metallurgy

Environmental pollution ultimately governs the economic or industrial growth rate of the world. Ideal green processes, both conceptual and feasible are discussed and the advantages and limitations are brought out. Typical examples of novel techniques developed to combat pollution are presented. An integrated approach coupling energy saving with pollution control measures appears to be the best strategy

Process Engineering for Pollution Control and Waste Minimisation in Non -Ferrous Metallurgical Industries

The importance of industrial ecology in the materials cycle has been stressed.The different approaches to process design have been outlined and typical applications to non-ferrous metallurgy have been highlighted. The challenges and opportunities for pollution control and waste minimisation in the non-ferrous metallurgical industries with reference to gaseous emissions, liquid effluents and solid wastes have been examined