Simulation of a new Pressure Swing Batch Distillation System

The operation and performance of a new pressure swing batch distillation configuration is investigated by rigorous simulation calculations. A maximum boiling point azeotrope is separated in a double column batch rectifier. We study the influence of the main operational parameters and determine the optimal value of these parameters. The calculation results are presented for the mixture water (A) – ethylene-diamine (B)

A polarization interferometer for coherent optical image processing

Imperial Users onl

Smart Materials as Intelligent Insulation

In order to provide a robust infrastructure for the transmission and distribution of electrical power, understanding and monitoring equipment ageing and failure is of paramount importance. Commonly, failure is associated with degradation of the dielectric material; therefore the introduction of a smart moiety into the material is a potentially attractive means of continual condition monitoring. It is important that any introduction of smart groups into the dielectric does not have any detrimental effect on the desirable electrical and mechanical properties of the bulk material. Initial work focussed on the introduction of fluorophores into a model dielectric system. Fluorescence is known to be a visible effect even at very low concentrations of active fluorophores and therefore was thought well suited to such an application. It was necessary both to optimise the active fluorophore itself and to determine the most appropriate manner in which to introduce the fluorophores into the insulating system. This presentation will describe the effect of introducing fluorophores into polymeric systems on the dielectric properties of the material and the findings thus far [1]. Alternative smart material systems will also be discussed along with the benefits and limitations of smart materials as electric field sensors

Updates of PDFs in the MSTW framework

I present results on updates on PDFs which are obtained within the general framework which led to the MSTW2008 PDF sets. There are some theory and procedural improvements and a variety of new data sets, including many relevant up-to-date LHC data. A new set of PDFs is very close to being finalised, with no significant changes expected to the preliminary PDFs shown here.Comment: 6 pages, 6 figures,Published in PoS DIS (2014

Poisson sigma models and symplectic groupoids

We consider the Poisson sigma model associated to a Poisson manifold. The perturbative quantization of this model yields the Kontsevich star product formula. We study here the classical model in the Hamiltonian formalism. The phase space is the space of leaves of a Hamiltonian foliation and has a natural groupoid structure. If it is a manifold then it is a symplectic groupoid for the given Poisson manifold. We study various families of examples. In particular, a global symplectic groupoid for a general class of two-dimensional Poisson domains is constructed.Comment: 34 page

Who controls East Asian corporations ?

The authors identify the ultimate ownership structure for 2,980 corporations in nine East Asian countries. They find that: A) More than half of those firms are controlled be a single shareholder. B) Smaller firms and older firms are more likely to be family-controlled. C) Patterns of controlling ownership stakes differ across countries. The concentration of control generally diminishes with higher economic and institutional development. D) In many countries control is enhanced though pyramid structures and deviations from one-share-one-vote rules. As a result, voting rights exceed cash-flow rights. E) Management is rarely separated from ownership control, and management in two thirds of the firms that are not widely held is related to management of the controlling shareholder. F) In some countries, wealth is very concentrated and links between government andbusiness are extensive, so the legal system has probably been influenced by the prevailing ownership structure.Small and Medium Size Enterprises,Microfinance,Small Scale Enterprise,International Terrorism&Counterterrorism,Economic Theory&Research,Microfinance,Private Participation in Infrastructure,Small Scale Enterprise,Rural Land Policies for Poverty Reduction,Economic Theory&Research

Evidence for Lattice Effects at the Charge-Ordering Transition in (TMTTF)2_2X

High-resolution thermal expansion measurements have been performed for exploring the mysterious "structureless transition" in (TMTTF)$_{2}$X (X = PF$_{6}$ and AsF$_{6}$), where charge ordering at $T_{CO}$ coincides with the onset of ferroelectric order. Particularly distinct lattice effects are found at $T_{CO}$ in the uniaxial expansivity along the interstack $\textbf{\textit{c*}}$-direction. We propose a scheme involving a charge modulation along the TMTTF stacks and its coupling to displacements of the counteranions X$^{-}$. These anion shifts, which lift the inversion symmetry enabling ferroelectric order to develop, determine the 3D charge pattern without ambiguity. Evidence is found for another anomaly for both materials at $T_{int}$ $\simeq$ 0.6 $\cdot$ $T_{CO}$ indicative of a phase transition related to the charge ordering

Bipolarons from long range interactions: Singlet and triplet pairs in the screened Hubbard-Froehlich model on the chain

We present details of a continuous-time quantum Monte-Carlo algorithm for the screened Hubbard-Froehlich bipolaron. We simulate the bipolaron in one dimension with arbitrary interaction range in the presence of Coulomb repulsion, computing the effective mass, binding energy, total number of phonons associated with the bipolaron, mass isotope exponent and bipolaron radius in a comprehensive survey of the parameter space. We discuss the role of the range of the electron-phonon interaction, demonstrating the evolution from Holstein to Froehlich bipolarons and we compare the properties of bipolarons with singlet and triplet pairing. Finally, we present simulations of the bipolaron dispersion. The band width of the Froehlich bipolaron is found to be broad, and the decrease in bandwidth as the two polarons bind into a bipolaron is found to be far less rapid than in the case of the Holstein interaction. The properties of bipolarons formed from long range electron-phonon interactions, such as light strongly bound bipolarons and intersite pairing when Coulomb repulsion is large, are found to be robust against screening, with qualitative differences between Holstein and screened Froehlich bipolarons found even for interactions screened within a single lattice site.Comment: 20 pages, 17 figure

Diversification and efficiency of investment by East Asian corporations

The East Asian financial crisis has been attributed in part to the corporate diversification associated with the misallocation of capital investment toward less profitable and more risky business segments. Much anecdotal evidence to support this view has surfaced since the crisis but there was little discussion of it before the crisis. Quite the contrary: The rapid expansion of East Asian firms by entering new business segments was viewed as contributing to the East Asian miracle. The authors examine the efficiency of investment by diversified corporations in nine East Asian countries, using unique panel data from more than 10,000 corporations for the pre-crisis period, 1991-96. They: 1) Document the degree of diversification in the corporate sector in Hong Kong, Indonesia, Japan, the Republic of Korea, Malaysia, the Philippines, Singapore, Taiwan (China), and Thailand, countries that have achieved enviable rates of economic growth over the past three decades. 2) Distinguished between vertical and complementary diversification and study the differences across nine countries. 3) Investigate whether diversification in East Asian has hurt economic efficiency. Their study tests the learning-by-doing and misallocation-of-capital hypotheses related to the types and degrees of diversification in East Asian countries. Firms in Indonesia, Korea, Taiwan, and Thailand appear to have suffered significant negative effects of vertical integration on short-term performance; the same countries gained significant short-term benefits from complementary expansion. The results suggests that the misallocation-of-capital hypothesis is appropriate for Korea and Malaysia; the learning-by-doing hypothesis for Indonesia, Taiwan, and Thailand. Firms in more developed countries succeed in vertically integrating and improve both short-term profitability and market valuation. Firms in more developed countries are ultimately more likely to benefit from such diversification (learn faster, to improve theirperformance). And diversification by firms in less developed countries is subject to more misallocation of capital.Microfinance,Fiscal&Monetary Policy,Economic Theory&Research,Small and Medium Size Enterprises,Small Scale Enterprise,Economic Theory&Research,Microfinance,Private Participation in Infrastructure,Small Scale Enterprise,Achieving Shared Growth