Papers

The polypyrrole-poly(methyl methacrylate)-fly ash (PPy/ PMMA/FA) composites were formed by in-citu polymerization of pyrrole in ammonium persulfate and PMMA latex medium in presence of fly ash. The structural characterization of the composite was carried out using XRD, SEM and FTIR techniques. A homogenous semicrystalline structure of the composite has been observed. The DC conductivity studies of the composite reveal that the conductivity increases with increasing FA component upto 35%. The microhardness of the composite is found to depend on the FA and PMMA components. Satisfactory conductivity of PPy+35%FA composite is exhibited when PMMA is mixed in the range of 5 to 10 %. The studies suggest that the addition of PMMA to PPy and FA composite can give rise to a conducting polymer composite with good mechanical stability.

In this paper, a problem of estimating the finite population mean in two phase sampling when information regarding the population proportion possessing certain attributes is considered. Under simple random sampling without replacement scheme, the expressions for mean square error of the proposed estimators have been obtained, up to the first order of approximation. The conditions under which the proposed estimators are more efficient than the mean per unit estimator have also been obtained. The gains in efficiency over the existing ones have been illustrated numerically.

The Jeans instability of homogeneous gaseous Plasma is discussed to investigate the effect of viscosity, rotation, thermalconductivity, electrical-resistivity, electron inertia and role of presence of fine dust particles and magnetic field on the self-gravitational instability. The usual magneto-hydrodynamic (MHD) equations are used for the present configuration with thermal-conductivity and finite dust particles. A general dispersion relation is obtained from the linearized perturbation equations using the normal mode analysis method. It is found that the Jeans criterion of instability is modified due to the presence of various parameters considered in our problem. The stability and instability are discussed for various cases as our interes

For the development of new software software reuse plays very important role. The idea of software reuse was projected in late sixties. Software reusability is the use of engineering knowledge or artifacts from existing software components to build a new system. Reusability is the key paradigm for increasing software quality in the software development. History of software development describes that area of software reusability was not so innovative. But it is believed that software reuse is still in the development phase and has not achieved its full potential. This paper describes how far we are with softwarereuse research which can get success in the field of Software reusability.

In the present study, we investigate the relationship between Coronal Mass Ejection (CME) and Cosmic ray intensity (CRI) variation on long-term basis. In this work, we have studied the effects of CMEs rates on cosmic rays for the period of 1996 to 2008. We have used three different neutron monitors data located at Beijing, Hermanus and Kiel. To carry out the study, we take all Coronal Mass Ejection data of LASCO during the period of solar cycle 23. From the analysis, we observed a good relationship between occurrence rate of CMEs and cosmic ray intensity variation

We reported the characteristics of coronal mass ejection and the Ap* Index of maximum 24-hour disturbance for storm events. The geoeffective fully backside and fully frontside CMEs are identified and is correlated with the CME speed. It is observed that the occurrence rate of both GE CMEs increases with the CME speed with in limit 400 km/sec. to 1400km/sec. and then the occurrence rate decreases with increase in CME speed. The Ap* values are correlated with Fully front side Halo CMEs, the sunspot number Rz, long wave length type II radio loud burst events RL and also with the amplitude of the I-Harmonic cosmic ray intensity CRI. A positive and significance correlation is observed

In this paper we present a very simple estimate of the spreading time, showing that it is very smaller than the Hawking evaporation time for the black hole i.e. t -tunnel 􀀀 tavap . String theory has given a set of states over which the wave function of the shell may spread