Concentrator cell methodology in the regeneration and recycle of chromium etching solutions using membrane technology

The regeneration of chromium (VI) and the recovery of etched copper from chromium etching solutions by electrodialysis is improved by the addition of a concentrator cell, using ion exchange resins or activated carbon cloth as concentrator media, in the catholyte chamber. The maximum percentages for the regeneration of chromium and recovery of copper in these systems is however less than 80 and 90% respectively because of the competition between the processes of oxidation of Cr(III) and electrodeposition of copper. A novel combination of electrolysis with electrodialysis and concentrator cell technology is developed that achieves 92.1% chromium regeneration and 90.4% copper recovery.EPSRC/DTI through the Link WMR03 programme and to Fluid Dynamics International Ltd. for financial support

Study of inland water transport in India - with emphasis on harmonization of rules

Presently in India there are various Acts and Regulations controlling the Inland Vessels. Since these regulations are framed by the different authorities there are many variations in the rules controlling the industry. It is not the purpose of this paper to set out rules for the Inland Vessels. The aim of this paper is to achieve harmonised standard for examination and survey of the inland vessels as well as examination and certification of personnel serving on board these vessels. Also to incorporate in the rules the immediate need for prevention of pollution of inland waters by the inland vessels, on the basis of different acts of the country, since none of the existing rules for the inland vessels deals with the question of pollution from these vessels. The paper projects the need for one rule and standardisation of navigational aids throughout the country, so that for examination as well as for actual navigation, operators do not face any practical difficulty

Effect of p-d hybridization and structural distortion on the electronic properties of AgAlM2 (M = S, Se, Te) chalcopyrite semiconductors

We have carried out ab-initio calculation and study of structural and electronic properties of AgAlM2 (M = S, Se, Te) chalcopyrite semiconductors using Density Functional Theory (DFT) based self consistent Tight binding Linear Muffin Tin orbital (TB-LMTO) method. Calculated equlibrium values of lattice constants, anion displacement parameter (u), tetragonal distortion ({\eta} = c/2a) and bond lengths have good agreement with experimental values. Our study suggests these semiconductors to be direct band gap semiconductors with band gaps 1.98 eV, 1.59 eV and 1.36 eV respectively. These are in good agreement with experimental value within the limitation of local density approximation (LDA). Our explicit study of the effects of anion displacement and p-d hybridization show that band gap increases by 9.8%, 8.2% and 5.1% respectively for AgAlM2 (M = S, Se, Te) due to former effect and decreases by 51%, 47% and 42% respectively due to later effect.Comment: 15 pages, 17 figures, This article has been communicated to Solid State Communication

Ecological Assessment of Sagebrush Grasslands in Eastern Wyoming

An understanding of existing ecosystem conditions is necessary for planning efforts that include formulation of landscape conservation goals and implementation strategies. In support of a landscape planning effort for a 946,000-ac mixed-ownership area in eastern Wyoming, we used remote sensing and field sampling to assess existing ecosystem conditions of terrestrial ecological sites. We used SPOT 5, 33-ft (10-m) multi-spectral satellite imagery combined with NRCS ecological sites to create a geographic information system layer of vegetation cover by ecological site. We then integrated the remote sensing information with field data (571 plots) collected from a stratified random design from 2003 through 2005. The integration of the field data with the satellite mapping provided specific information about each terrestrial ecological site including species composition, productivity, structure, and shrub cover. Western wheatgrass was the most dominant species across all of the terrestrial ecological sites followed by big sagebrush, needle and thread, blue grama, annual brome species and to a lesser extent threadleaf sedge, and six weeks fescue. We found species that typically decrease with grazing (for example green needlegrass, bluebunch wheatgrass, Indian ricegrass) to be lacking or entirely absent from plant communities. Introduced species, especially the annual bromes, were prevalent across all ecological sites. Over 55 percent of the terrestrial ecosystems we sampled had greater than five percent relative cover of introduced plant species. Current ecosystem conditions for many wildlife of the area, as identified by our assessment, had generally lower habitat quality than desired and treatments to improve these conditions are planned

Emergence of nanoscale inhomogeneity in the superconducting state of a homogeneously disordered conventional superconductor, NbN

The notion of spontaneous formation of an inhomogeneous superconducting state is at the heart of most theories attempting to understand the superconducting state in the presence of strong disorder. Using scanning tunneling spectroscopy and high resolution scanning transmission electron microscopy, we experimentally demonstrate that under the competing effects of strong homogeneous disorder and superconducting correlations, the superconducting state of a conventional superconductor, NbN, spontaneously segregates into domains. Tracking these domains as a function of temperature we observe that the superconducting domains persist across the bulk superconducting transition, Tc, and disappear close to the pseudogap temperature, T*, where signatures of superconducting correlations disappear from the tunneling spectrum and the superfluid response of the system