52 research outputs found

    Application of the SRISM approach to the study of the capacitance of the double layer of a high density primitive model electrolyte

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    In this study the Singlet Reference Interaction Site Model (SRISM) is employed to the study of the electrode charge dependence of the capacitance of a planar electric double layer using the primitive model of the double layer for a high density electrolyte that mimics an ionic liquid. The ions are represented by charged hard spheres and the electrode is a uniformly charged flat surface. The capacitance of this model fluid is calculated with the SRISM approach with closures based on the hypernetted chain (HNC) and Kovalenko-Hirata (KH) closures and compared with simulations. As long as the magnitude of the electrode charge is not too great, the HNC closure shows the most promise. The KH results are reasonably good for a high density electrolyte but are poor when applied at low densities.Comment: 6 pages, 2 figure

    Transfer matrices for the totally asymmetric exclusion process

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    We consider the totally asymmetric simple exclusion process (TASEP) on a finite lattice with open boundaries. We show, using the recursive structure of the Markov matrix that encodes the dynamics, that there exist two transfer matrices TL1,LT_{L-1,L} and T~L1,L\tilde{T}_{L-1,L} that intertwine the Markov matrices of consecutive system sizes: T~L1,LML1=MLTL1,L\tilde{T}_{L-1,L}M_{L-1}=M_{L}T_{L-1,L}. This semi-conjugation property of the dynamics provides an algebraic counterpart for the matrix-product representation of the steady state of the process.Comment: 7 page

    Opportunities for considering green infrastructure and ecosystems in the Sendai Framework Monitor

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    Ecosystem-based disaster risk reduction has gained attention to complement or replace grey infrastructure. The paper explores ways in which ecosystems and green infrastructure (GI) are critical infrastructure in the context of disaster risk reduction to report respective losses in the Sendai Framework Monitor (SFM). We argue that reporting on GI under indicators D-4 and C-5 in the SFM represent an opportunity for tracking losses, yet do not provide direct information on progress made in reducing risk. Custom targets and indicators according to countries' needs within the SFM might be a more practical opportunity to report on both losses and progress

    Decoherence-induced conductivity in the discrete 1D Anderson model: A novel approach to even-order generalized Lyapunov exponents

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    A recently proposed statistical model for the effects of decoherence on electron transport manifests a decoherence-driven transition from quantum-coherent localized to ohmic behavior when applied to the one-dimensional Anderson model. Here we derive the resistivity in the ohmic case and show that the transition to localized behavior occurs when the coherence length surpasses a value which only depends on the second-order generalized Lyapunov exponent ξ1\xi^{-1}. We determine the exact value of ξ1\xi^{-1} of an infinite system for arbitrary uncorrelated disorder and electron energy. Likewise all higher even-order generalized Lyapunov exponents can be calculated, as exemplified for fourth order. An approximation for the localization length (inverse standard Lyapunov exponent) is presented, by assuming a log-normal limiting distribution for the dimensionless conductance TT. This approximation works well in the limit of weak disorder, with the exception of the band edges and the band center.Comment: 12 pages, 5 figure

    Frozen shuffle update for an asymmetric exclusion process on a ring

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    We introduce a new rule of motion for a totally asymmetric exclusion process (TASEP) representing pedestrian traffic on a lattice. Its characteristic feature is that the positions of the pedestrians, modeled as hard-core particles, are updated in a fixed predefined order, determined by a phase attached to each of them. We investigate this model analytically and by Monte Carlo simulation on a one-dimensional lattice with periodic boundary conditions. At a critical value of the particle density a transition occurs from a phase with `free flow' to one with `jammed flow'. We are able to analytically predict the current-density diagram for the infinite system and to find the scaling function that describes the finite size rounding at the transition point.Comment: 16 page

    Some Exact Results for the Exclusion Process

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    The asymmetric simple exclusion process (ASEP) is a paradigm for non-equilibrium physics that appears as a building block to model various low-dimensional transport phenomena, ranging from intracellular traffic to quantum dots. We review some recent results obtained for the system on a periodic ring by using the Bethe Ansatz. We show that this method allows to derive analytically many properties of the dynamics of the model such as the spectral gap and the generating function of the current. We also discuss the solution of a generalized exclusion process with NN-species of particles and explain how a geometric construction inspired from queuing theory sheds light on the Matrix Product Representation technique that has been very fruitful to derive exact results for the ASEP.Comment: 21 pages; Proceedings of STATPHYS24 (Cairns, Australia, July 2010

    Fast calculation of thermodynamic and structural parameters of solutions using the 3DRISM model and the multi-grid method

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    In the paper a new method to solve the tree-dimensional reference interaction site model (3DRISM) integral equations is proposed. The algorithm uses the multi-grid technique which allows to decrease the computational expanses. 3DRISM calculations for aqueous solutions of four compounds (argon, water, methane, methanol) on the different grids are performed in order to determine a dependence of the computational error on the parameters of the grid. It is shown that calculations on the grid with the step 0.05\Angstr and buffer 8\Angstr give the error of solvation free energy calculations less than 0.3 kcal/mol which is comparable to the accuracy of the experimental measurements. The performance of the algorithm is tested. It is shown that the proposed algorithm is in average more than 12 times faster than the standard Picard direct iteration method.Comment: the information in this preprint is not up to date. Since the first publication of the preprint (9 Nov 2011) the algorithm was modified which allowed to achieve better results. For the new algorithm see the JCTC paper: DOI: 10.1021/ct200815v, http://pubs.acs.org/doi/abs/10.1021/ct200815

    Solvation free energy profile of the SCN- ion across the water-1,2-dichloroethane liquid/liquid interface. A computer simulation study

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    The solvation free energy profile of a single SCN- ion is calculated across the water-1,2-dichloroethane liquid/liquid interface at 298 K by the constraint force method. The obtained results show that the free energy cost of transferring the ion from the aqueous to the organic phase is about 70 kJ/mol, The free energy profile shows a small but clear well at the aqueous side of the interface, in the subsurface region of the water phase, indicating the ability of the SCN- ion to be adsorbed in the close vicinity of the interface. Upon entrance of the SCN- ion to the organic phase a coextraction of the water molecules of its first hydration shell occurs. Accordingly, when it is located at the boundary of the two phases the SCN- ion prefers orientations in which its bulky S atom is located at the aqueous side, and the small N atom, together with its first hydration shell, at the organic side of the interface

    Ionic liquids at electrified interfaces

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    Until recently, “room-temperature” (<100–150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)–(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of “first-generation” room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the “later generation” RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in “cocktails” of one’s choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost “universal” solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) “sister-systems”.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules

    Children and Their Parents: A Comparative Study of the Legal Position of Children with Regard to Their Intentional and Biological Parents in English and Dutch Law

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    This is a book about children and their parents. There are many different kinds of children and at least about as many different kinds of parents. In addition to the many different disciplines that study children and their parents, such as sociology, psychology, child studies and gender studies, to name but a few, this study concerns a legal question with regard to the parent-child relationship, namely how the law assigns parents to children. This subject is approached in a comparative legal perspective and covers England and The Netherlands. The book contains a detailed comparison and analysis of the manner in which the law in the two jurisdictions assigns the status of legal parent and/or attributes parental responsibility to the child’s biological and intentional parents. The concept ‘procreational responsibility’, which is introduced in the concluding chapter of the book, may be used as a tool to assess and reform existing regulations on legal parent-child relationships. The structure of the book, which is based on a categorisation of different family types in a ‘family tree’, enables the reader to have easy access to family-specific information.FdR – Publicaties zonder aanstelling Universiteit Leide
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