Cyclopentadienyl platinum complexes and organic group transfer reactions

No abstract availabl

Some Experiments on the Electrical Conductivity of Atmospheric Air

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The Steady State Distribution of the Master Equation

The steady states of the master equation are investigated. We give two expressions for the steady state distribution of the master equation a la the Zubarev-McLennan steady state distribution, i.e., the exact expression and an expression near equilibrium. The latter expression obtained is consistent with recent attempt of constructing steady state theormodynamics.Comment: 6 pages, No figures. A mistake was correcte

Changing the rules of the game: mechanisms that shape responsibility-sharing from beyond Australian fire and emergency management

In this paper, we look beyond Australian fire and emergency management to compare ways that responsibility-sharing - broadly conceived - has occurred in other places and sectors where risks to community safety are faced. Responsibility-sharing occurs any time there is collective action, and formal and informal institutions provide the 'rules of the game' that prescribe how responsibility should be shared amongst the parties involved. We reviewed a broad sample of risk research literature in order to examine by what mechanisms responsibility-sharing institutions have been shaped in other places and sectors where risks to community safety are faced. Our review revealed more alternatives for shaping responsibilitysharing institutions than are widely considered by policy and decision makers in Australian fire and emergency management. It therefore raises an important question about why certain mechanisms are chosen, prioritised, overlooked or resisted in this sector. An alternative way of conceiving and pursuing shared responsibility is also discussed

Breakdown of hydrodynamics in the inelastic Maxwell model of granular gases

Both the right and left eigenfunctions and eigenvalues of the linearized homogeneous Boltzmann equation for inelastic Maxwell molecules corresponding to the hydrodynamic modes are calculated. Also, some non-hydrodynamic modes are identified. It is shown that below a critical value of the parameter characterizing the inelasticity, one of the kinetic modes decays slower than one of the hydrodynamic ones. As a consequence, a closed hydrodynamic description does not exist in that regime. Some implications of this behavior on the formally computed Navier-Stokes transport coefficients are discussed.Comment: Submitted to PRL (13/04/10

Physicochemical properties of concentrated Martian surface waters

Understanding the processes controlling chemical sedimentation is an important step in deciphering paleoclimatic conditions from the rock records preserved on both Earth and Mars. Clear evidence for subaqueous sedimentation at Meridiani Planum, widespread saline mineral deposits in the Valles Marineris region, and the possible role of saline waters in forming recent geomorphologic features all underscore the need to understand the physical properties of highly concentrated solutions on Mars in addition to, and as a function of, their distinct chemistry. Using thermodynamic models predicting saline mineral solubility, we generate likely brine compositions ranging from bicarbonate-dominated to sulfate-dominated and predict their saline mineralogy. For each brine composition, we then estimate a number of thermal, transport, and colligative properties using established models that have been developed for highly concentrated multicomponent electrolyte solutions. The available experimental data and theoretical models that allow estimation of these physicochemical properties encompass, for the most part, much of the anticipated variation in chemistry for likely Martian brines. These estimates allow significant progress in building a detailed analysis of physical sedimentation at the ancient Martian surface and allow more accurate predictions of thermal behavior and the diffusive transport of matter through chemically distinct solutions under comparatively nonstandard conditions

An expression for stationary distribution in nonequilibrium steady state

We study the nonequilibrium steady state realized in a general stochastic system attached to multiple heat baths and/or driven by an external force. Starting from the detailed fluctuation theorem we derive concise and suggestive expressions for the corresponding stationary distribution which are correct up to the second order in thermodynamic forces. The probability of a microstate $\eta$ is proportional to $\exp[{\Phi}(\eta)]$ where ${\Phi}(\eta)=-\sum_k\beta_k\mathcal{E}_k(\eta)$ is the excess entropy change. Here $\mathcal{E}_k(\eta)$ is the difference between two kinds of conditioned path ensemble averages of excess heat transfer from the $k$-th heat bath whose inverse temperature is $\beta_k$. Our expression may be verified experimentally in nonequilibrium states realized, for example, in mesoscopic systems.Comment: 4 pages, 2 figure

Chapman-Enskog expansion about nonequilibrium states: the sheared granular fluid

The Chapman-Enskog method of solution of kinetic equations, such as the Boltzmann equation, is based on an expansion in gradients of the deviations fo the hydrodynamic fields from a uniform reference state (e.g., local equilibrium). This paper presents an extension of the method so as to allow for expansions about \emph{arbitrary}, far-from equilibrium reference states. The primary result is a set of hydrodynamic equations for studying variations from the arbitrary reference state which, unlike the usual Navier-Stokes hydrodynamics, does not restrict the reference state in any way. The method is illustrated by application to a sheared granular gas which cannot be studied using the usual Navier-Stokes hydrodynamics.Comment: 23 pages, no figures. Submited to PRE Replaced to correct misc. errors Replaced to correct misc. errors, make notation more consistant, extend discussio

Quantum Transport with Dissipation: Linear and Non-Linear Response

We present a quantum transport equation derived under the simplifying assumption that the inelastic scattering is caused by uncorrelated point scatterers, such as magnetic impurities. While this assumption is not always realistic, we believe that the model can be used to describe much of the essential physics of quantum transport in mesoscopic systems. This assumption allows us to write a quantum transport equation that involves only the diagonal elements of the density matrix which we use to define a distribution function f(r; E). The kernel of this integral equation is calculated from the Schrodinger equation and contains all quantum interference effects. We show that at equilibrium the distribution function relaxes to the Fermi-Dirac function with a constant chemical potential everywhere in the structure. Assuming local thermodynamic equilibrium we then derive a linearized transport equation which has the appearance of a continuous version of the multiprobe Landauer formula. An alternative derivation is provided for the linearized transport equation starting from the multiprobe Landauer formula. Numerical results are presented for the conductivity of a disordered resistor with distributed inelastic scattering. A clear transition is observed from weak to strong localization as the inelastic scattering time is increased. In the present work we restrict ourselves to steady state transport and neglect many-body effects

An Integral Equation for Dissipative Quantum Transport

We present an integral equation derived under the simplifying assumption that the inelastic scattering is caused by uncorrelated point scatterers, such as magnetic impurities or impurities with internal degrees of freedom. While this assumption is not always realistic, we believe that the model can be used to describe much of the essential physics of quantum transport in mesoscopic systems. This assumption allows us to write a transport equation that involves only the electron density and not the spatial correlations of the wave function. The kernel of this integral equation is calculated from the Schrodinger equation and contains all quantum interference effects. We show that at equilibrium the electron density relaxes to the expected equilibrium value with a constant chemical potential everywhere in the structure. Assuming local thermodynamic equilibrium we then derive a linear-response transport equation which resembles the Landauer-Buttiker formula extended to include a continuous distribution of probes. An alternative derivation is provided in the appendix for the kernel of the linear-response transport equation, starting from the Kubo formula for the conductivity. We discuss the conditions under which this transport equation reduces to the well-known drift-diffusion equations describing classical Brownian motion. In the present work we restrict ourselves to steady state transport and neglect many-body effects beyond the Hartree term