Nuclear incompressibility using the density dependent M3Y effective interaction

A density dependent M3Y effective nucleon-nucleon (NN) interaction which was based on the G-matrix elements of the Reid-Elliott NN potential has been used to determine the incompressibity of infinite nuclear matter. The nuclear interaction potential obtained by folding in the density distribution functions of two interacting nuclei with this density dependent M3Y effective interaction had been shown earlier to provide excellent descriptions for medium and high energy $\alpha$ and heavy ion elastic scatterings as well as $\alpha$ and heavy cluster radioactivities. The density dependent parameters have been chosen to reproduce the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. The result of such calculations for nuclear incompressibility using the density dependent M3Y effective interaction based on the G-matrix elements of Reid-Elliott NN potential predicts a value of about 300 MeV for nuclear incompressibility.Comment: 4 Page

Scaling and universality in coupled driven diffusive models

Inspired by the physics of magnetohydrodynamics (MHD) a simplified coupled Burgers-like model in one dimension (1d), a generalization of the Burgers model to coupled degrees of freedom, is proposed to describe 1dMHD. In addition to MHD, this model serves as a 1d reduced model for driven binary fluid mixtures. Here we have performed a comprehensive study of the universal properties of the generalized d-dimensional version of the reduced model. We employ both analytical and numerical approaches. In particular, we determine the scaling exponents and the amplitude-ratios of the relevant two-point time-dependent correlation functions in the model. We demonstrate that these quantities vary continuously with the amplitude of the noise cross-correlation. Further our numerical studies corroborate the continuous dependence of long wavelength and long time-scale physics of the model on the amplitude of the noise cross-correlations, as found in our analytical studies. We construct and simulate lattice-gas models of coupled degrees of freedom in 1d, belonging to the universality class of our coupled Burgers-like model, which display similar behavior. We use a variety of numerical (Monte-Carlo and Pseudospectral methods) and analytical (Dynamic Renormalization Group, Self-Consistent Mode-Coupling Theory and Functional Renormalization Group) approaches for our work. The results from our different approaches complement one another. Possible realizations of our results in various nonequilibrium models are discussed.Comment: To appear in JSTAT (2009); 52 pages in JSTAT format. Some figure files have been replace

The role of institutional and family embeddedness in the failure of Sub-Saharan African migrant family businesses

There is considerable interest among European politicians and policymakers in how to integrate migrants in the local and national economy. Drawing on in-depth qualitative interviews with 20 owners of Sub-Saharan African migrant family businesses (SSAMBs) in the United Kingdom, this article critically examines why SSAMBs fail or underperform. This investigation draws upon three streams of literature – notably migrant business failure, institutional theory and family embeddedness. The findings highlight the challenges of doing business and the reasons for business failure among this group. These are different from other small businesses and include culture, family interference and ethnicity. The main contribution of the article lies in the development of a conceptual model that highlights the relationships between institutional contexts and migrant family business outcomes. The model proposes that institution and family embeddedness results in the enactment of ethnic behaviours that drive migrant businesses into cultural markets leading to business underperformance or failure

Techno-economic aspects of Alternative Metallic Charges in EAF Steelmaking

Electrical arc furnace steelmaking originated with the work of Sir Williams Siemens who in 1878 constructed, operated and patented furnaces operating on both the direct arc and indirect arc principles. The development of the electric melting furnace, however, had to await the expansion of the electric power industry and improvement in carbon electrodes. The use of electric arc furnace for steel making was perhaps first adopted in the laterpart of the 19th and beginningof the 20th century. Major commercial applications of the process began with the production of low alloy steels and subsequently high alloy and special steels. With the developments that have taken place over the years in EAF technology, ladle metallurgical and continuous casting, EAF plants are now entering into new areas, hitherto considered as exclusive domain of conventional large integrated steelmakers. Today Electric Arc Furnace (EAF) steelmaking accounts forover 30 per cent of the crude steel production in developed countries like USA, Japan and nearly 100 percent in the oil/gas rich countries of the Gulf region and the Middle East

Optical Generation and Quantitative Characterizations of Electron-hole Entanglement

Using a method of characterizing entanglement in the framework of quantum field theory, we investigate the optical generation and quantitative characterizations of quantum entanglement in an electron-hole system, in presence of spin-orbit coupling, and especially make a theoretical analysis of a recent experimental result. Basically, such entanglement should be considered as between occupation numbers of single particle basis states, and is essentially generated by coupling between different single particle basis states in the second quantized Hamiltonian. Interaction with two resonant light modes of different circular polarizations generically leads to a superposition of ground state and two heavy-hole excitonic states. When and only when the state is a superposition of only the two excitonic eigenstates, the entanglement reduces to that between two distinguishable particles, each with two degrees of freedom, namely, band index, as characterized by angular momentum, and orbit, as characterized by position or momentum. The band-index state, obtained by tracing over the orbital degree of freedom, is found to be a pure state, hence the band-index and orbital degrees of freedom are separated in this state. We propose some basic ideas on spatially separating the electron and the hole, so that the entanglement of band-indices, or angular momenta, is between spatially separated electron and hole.Comment: 8 pages. Journal versio

A Multi-dimensional Code for Isothermal Magnetohydrodynamic Flows in Astrophysics

We present a multi-dimensional numerical code to solve isothermal magnetohydrodynamic (IMHD) equations for use in modeling astrophysical flows. First, we have built a one-dimensional code which is based on an explicit finite-difference method on an Eulerian grid, called the total variation diminishing (TVD) scheme. Recipes for building the one-dimensional IMHD code, including the normalized right and left eigenvectors of the IMHD Jacobian matrix, are presented. Then, we have extended the one-dimensional code to a multi-dimensional IMHD code through a Strang-type dimensional splitting. In the multi-dimensional code, an explicit cleaning step has been included to eliminate non-zero $\nabla\cdot B$ at every time step. To estimate the proformance of the code, one- and two-dimensional IMHD shock tube tests, and the decay test of a two-dimensional Alfv\'{e}n wave have been done. As an example of astrophysical applications, we have simulated the nonlinear evolution of the two-dimensional Parker instability under a uniform gravity.Comment: Accepted for publication in ApJ, using aaspp4.sty, 22 text pages with 10 figure

On small combination of slices in Banach spaces

The notion of Small Combination of Slices (SCS) in the unit ball of a Banach space was first introduced in [4] and subsequently analyzed in detail in [12] and [13]. In this work, we introduce the notion of BSCSP, which can be seen as a generalization of dentability in terms of SCS. We study certain stability results for the w*-BSCSP leading to a discussion on BSCSP in the context of ideals of Banach spaces. We prove that the w*-BSCSP can be lifted from a M-ideal to the whole Banach Space. We also prove similar results for strict ideals and U-subspaces of a Banach space. We note that the space C(K;X)* has w*-BSCSP when K is dispersed and X* has the w*-BSCSP.peerReviewe