Stochastic ratcheting of two dimensional colloids : Directed current and dynamical transitions

We present results of molecular dynamics simulations for two-dimensional repulsively interacting colloids driven by a one dimensional asymmetric and commensurate ratchet potential, switching on and off stochastically. This drives a time-averaged directed current of colloids, exhibiting resonance with change in ratcheting frequency, where the resonance frequency itself depends non-monotonically on density. Using scaling arguments, we obtain analytic results that show good agreement with numerical simulations. With increasing ratcheting frequency, we find non-equilibrium re-entrant transitions between solid and modulated liquid phases.Comment: paper and supplementary; published versio

Clustering Techniques for Land Use Land Cover Classification of Remotely Sensed Images

Image processing is growing fast and persistently. The idea of remotely sensed image clustering is to categorize the image into meaningful land use land cover classes with respect to a particular application. Image clustering is a technique to group an image into units or categories that are homogeneous with respect to one or more characteristics. There are many algorithms and techniques that have been developed to solve image clustering problems, though, none of the method is a general solution. This chapter will highlight the various clustering techniques that bring together the current development on clustering and explores the potentiality of those techniques in extracting earth surface features information from high spatial resolution remotely sensed imageries. It also will provide an insight about the existing mathematical methods and its application to image clustering. Special emphasis will be given on Hölder exponent (HE) and Variance (VAR). HE and VAR are well-established techniques for texture analysis. This chapter will highlight about the Hölder exponent and variance-based clustering method for classifying land use/land cover in high spatial resolution remotely sensed images

Catalytic Hydrodehalogenative coupling of Dichlorodifluoromethane on Supported Platinum and Palladium Bimetallic Catalysts

Ethylene and propylene are very important chemicals used as feedstocks in modern days. Halocarbons can be a promising starting material to form C-C coupling products. The biggest challenge of forming coupling products from chlorofluorocarbons (CFCs) is to improve the coupling pathways by suppressing other paths of reactions that produce less attractive products.The kinetics results of the reaction of CF2Cl2 and H2 catalyzed by PtCu/C catalysts, presented in Chapter 3, showed the effect of Cu content on the selectivity pattern. The observation was that the coupling selectivity increased with the increasing Cu content. The observation led to the investigation of the role of Cu sites in the coupling product formation. Chapter 4 discusses the results of introducing CO in the reaction mixture. The maximum coupling selectivity was increased from 55% to 69%. The catalyst was also exposed to water for better mixing of the precursors. The water-exposed catalyst showed an overall coupling selectivity of ~82% and the performance was very stable. It was suggested that water exposure of the fresh catalyst increased bimetallic particle formation. As a result the number and size of Pt particles decreased. Both the results point toward fact that Pt or bimetallic sites may be responsible for C1 product formation and Cu sites are responsible for coupling products formation.The performances of the palladium bimetallic catalysts were discussed in chapter 5. Monometallic Pd produced 75% hydrocarbon oligomerization products (C2 to C5) and monometallic Cu, Ag, Co and Fe/C were inactive under the reaction condition. For Pd-Ag/C catalyst, there might be a very significant amount of bimetallic particle formation and Ag segregates hugely to the surface of the bimetallic particles. The hydrodehalogenation and coupling reactions are occurring over the Ag sites. For Pd-Cu there will be a moderate surface segregation of Cu to the surface and there will be just enough Pd surface atoms to dissociate hydrogen to Cu sites for dehalogenation and coupling. For Pd-Co/C, the function of Co is just to dilute the Pd ensemble. For Pd-Fe, Fe acts as Pd site blocking and Pd ensemble size reducing element. Two of the bimetallic catalysts (Pd-Cu and Pd-Co) were very stable though their activities were lower than monometallic Pd

Unraveling the success of India’s IT-ITES industry: Can India sustain this success?

India has established itself as a global leader in the Information Technology-Information Technology Enabled Services (IT-ITES) offshoring industry. Different factors have been responsible for India’s success. In this paper we examine the success of India’s IT-ITES industry from multiple lenses to present a holistic view. Research frameworks from the Information Systems and International Business literature are reviewed to understand the factors that led to the success of Indian IT-ITES industry since the emergence of offshoring. To develop a deeper understanding of the success of India’s IT-ITES industry and provide guidelines for the future, we use International Trade theory to explain what happened before the emergence of offshoring that led to the development of the Indian IT-ITES industry. The multidimensional view presented in the paper helps understand the bigger picture in the context of the offshoring phenomenon

Interpreting the bounds on Solar Dark Matter induced muons at Super-Kamiokande in the light of CDMS results

We consider the recent limits on dark matter - nucleon elastic scattering cross section from the analysis of CDMS II collaboration using the two signal events observed in CDMS experiment. With these limits we try to interpret the Super-Kamiokande (SK) bounds on the detection rates of up-going muons induced by the neutrinos that are produced in the sun from the decay of annihilation products of dark matter (WIMPs) captured in the solar core. Calculated rates of up-going muons for different annihilation channels at SK using CDMS bounds are found to be orders below the predicted upper limits of such up-going muon rates at SK. Thus there exists room for enhancement (boost) of the calculated rates using CDMS limits for interpreting SK bounds. Such a feature is expected to represent the PAMELA data with the current CDMS limits. We also show the dependence of such a possible enhancement factor (boost) on WIMP mass for different WIMP annihilation channels.Comment: 7 pages, 6 figure