Effect of copper chelates on U.V. stability of butyl rubber and SBR rubber

An investigation of the photo-oxidative degradation and stabilization of IIR and SBR in the temperature range of 258 to 313°K in air with a monochromatic light of 366 nm in the absence and presence of various concentrations of the different copper chelates has been described. The stabilizer performance in IIR and SBR was accessed by carbonyl index and quantum yield measurements. The changes of IIR and SBR during the irradiation with an ultra-violet light (366 nm) have been conducted by viscometrically and actinometric techniques. Irradiations were conducted on the films at 0, 2, 4, 6, 8, 10, 12 and 14 hours and various parameters were obtained.     

Graft-copolymerization of starch with acrylamide,II. Thermal behaviour of graft copolymers

Thermal behaviour of starch-graft-polyacrylamide (S-g-PAM) copolymers was evaluated. Grafting of polyacrylamide onto starch lowers the initial decomposition temperature. However, the over-all stability as assessed by the shape of thermogravimetric curve and integral procedural decomposition temperature increased with an increase in % graft-on.     

A Scenario Based Impact Assessment of Trace Metals on Ecosystem of River Ganges Using Multivariate Analysis Coupled with Fuzzy Decision-Making Approach

The growing consciousness about the health risks associated with environmental pollutants has brought a major shift in global concern towards prevention of hazardous/trace metals discharge in water bodies. Majority of these trace metals gets accumulated in the body of aquatic lives, which are considered as potential indicators of hazardous content. This results in an ecological imbalance in the form of poisoning, diseases and even death of fish and other aquatic lives, and ultimately affect humans through food chain. Trace metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn originated from various industrial operations containing metallic solutions and agricultural practices, have been contributing significantly to cause aquatic pollution. The present study develops a novel approach of expressing sustainability of river’s ecosystem based on health of the fish by coupling fuzzy sensitivity analysis into multivariate analysis. A systematic methodology has been developed by generating monoplot, two dimensional biplot and rotated component matrix (using ‘Analyze it’ and ‘SPSS’ software), which can simultaneously identify critical trace metals and their industrial sources, critical sampling stations, and adversely affected fish species along with their interrelationships. A case study of assessing the impact of trace metals on the aquatic life of river Ganges, India has also been presented to demonstrate effectiveness of the model. The clusters pertaining to various water quality parameters have been identified using Principal Component Analysis (PCA) to determine actual sources of pollutants and their impact on aquatic life. The fuzzy sensitivity analysis reveals the cause-effect relationship of these critical parameters. The study suggests pollution control agencies to enforce appropriate regulations on the wastewater dischargers responsible for polluting river streams with a particular kind of trace metal(s).     

Particle-in-Cell algorithms for emerging computer architectures

We have designed Particle-in-Cell algorithms for emerging architectures. These algorithms share a common approach, using fine-grained tiles, but different implementations depending on the architecture. On the GPU, there were two different implementations, one with atomic operations and one with no data collisions, using CUDA C and Fortran. Speedups up to about 50 compared to a single core of the Intel i7 processor have been achieved. There was also an implementation for traditional multi-core processors using OpenMP which achieved high parallel efficiency. We believe that this approach should work for other emerging designs such as Intel Phi coprocessor from the Intel MIC architecture.     

ESTIMATION OF VAPOR PRESSURES OF ORGANIC NITROGEN AND SULFUR COMPOUNDS BY A GROUP-CONTRIBUTION METHOD

The group-contribution method for vapor pressures of hydrocarbons and organic compounds containing nitrogen or sulfur, based on the kinetic theory of fluids, is revised and extended to include new groups containing nitrogen or sulfur. Good representation is obtained for vapor pressure data in the region 1.30-270 kPa. The method may be used to estimate vapor pressures and enthalpies of vaporization for those organic fluids containing nitrogen or sulfur, where no experimental data are available.     

A hybrid evolutionary approach to the registration area planning problem

The last two decades have witnessed a phenomenal growth in the number of cellular wireless network users which in turn stressed the need to utilize the limited network bandwidth in an efficient manner. The network bandwidth is consumed not only by user traffic, but also by control traffic needed for ensuring the mobility of users. As we don’t have any control over the volume of user traffic, all attempts to efficiently use bandwidth are based on frequency reuse and minimizing the control traffic. The registration area planning (RAP) problem seeks a partition of the cells of the network into contiguous areas called registration areas so that the bandwidth consumed by control signals is minimized. RAP problem in an \(\mathcal {NP}\) -Hard problem. In this paper, we present a steady-state grouping genetic algorithm with local search to solve this problem. We have compared our approach with the state-of-the-art approaches reported in the literature. Computational results show the effectiveness of our approach.     

Response of wheat (Triticum aestivum) and pearl-millet (Pennistum americanum) to zinc fertilizers on two soils

Responses of ZnSO₄, Zn₃ (PO₄)₂ · 4H₂O, ZnO, ZnNH₄PO₃ · 2H₂O and zincated superphosphate were studied on wheat (Triticum aestivum) and pearl-millet (Pennistem americanum) in Balsamand sand (Ustipsament) and Ladwa fine loam (Typic Camborthids). In Balsamand sand all Zn fertilizers increased wheat and pearl-milllet grain yield significantly over control but ZnNH₄ PO₄ · 2H₂O and zincated super were the best sources. Straw yield was also highest due to zincated super and ZnNH₄PO₄ · 2H₂O applications. Zinc sulphate was significantly inferior to zincated super and ZnNH₄PO₄ · 2H₂O. In Ladwa fine loam, all fertilizers gave significantly higher grain yield of wheat and pearl-millet than control except ZnO in pearl-millet. Highest yield in this soil was obtained by ZnSO₄ · 7H₂O followed by ZnNH₄ PO₄ · 2H₂O and then zincated super.In Balsamand sand, the Zn fertilizers significantly increased the Zn concentration and Zn uptake of wheat grain. In pearl-millet, only Zn uptake was increased significantly with Zn fertilizers. Zincated super gave highest Zn uptake.The concentration of P in wheat grain was increased by Zn fertilizers in Balsamand sand, and also in pearl-millet where zincated super and ZnNH₄PO₄ were most effective in increasing the P content.When Zn fertilizers were applied to preceding pearl-millet the effect on succeeding wheat crop were in the same order as direct application of Zn fertilizers. Zincated super was the best and ZnO worst with respect to wheat grain and straw yield and uptake of Zn and P.     

Hydration Study of the System Ca3Al2O6–CaSO4· 2H2O–Ca(OH)2–H2O with and without Citric Acid

Hydration occurring in the system Ca₃Al₂O₆–CaSO₄· 2H₂O–Ca(OH)₂–H₂O has been studied at different temperatures and it was found that the reactions are diffusion controlled. The kinetic data obeyed Jander's equation and the rate of reaction increased with increasing temperature. X-ray diffraction studies and calorimetric measurements show that when gypsum is consumed, ettringite is converted into monosulfate. The rate of this conversion also increased with the increasing temperature and decreased in the presence of citric acid. Spectroscopic studies showed that there was some interaction between citric acid and the cement and that the product of hydration is of colloidal nature. Zeta potential measurements show that retardation of Ca₃Al₂O₆ hydration in the presence of gypsum and Ca(OH)₂ is not due to SO²⁻₄ adsorption. Electrical conductivity and thermoelectric potential measurements of solid Ca₃Al₂O₆ show that Ca₃Al₂O₆ is an n -type semiconductor and contains defects. The retardation of Ca₃Al₂O₆ may be due to poisoning of reaction sites by gypsum and Ca(OH)_2.     

Diffusion coefficient in polymer solutions

Molecular diffusivity of a solute in a solvent may be determined by measuring the extent of dispersion of solute in solvent flowing in a straight circular tube under the conditions of laminar flow. This simple and rapid method for determination of molecular diffusivity in aquous polymer solutions is discussed. Experimental results show a substantial reduction in the solute diffusivity with increase in polymer concentration.