The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform

P.a. Giuliano Albo - One of the best experts on this subject based on the ideXlab platform.

  • a novel application of Recursive Equation method for determining thermodynamic properties of single phase fluids from density and speed of sound measurements
    The Journal of Chemical Thermodynamics, 2013
    Co-Authors: S. Lago, P.a. Giuliano Albo
    Abstract:

    Abstract The determination of thermal quantities from mechanical properties is still a challenge in the thermodynamic field. In this work, the authors suggest a preliminary numerical calculation which allows to determine the constant pressure specific heat capacity, starting from density and speed-of-sound experimental values, as input data. This method is a variant of the well characterized Recursive Equation Method (REM) [1] and permits to develop empirical Equations of state for single phase fluids. In particular, the isobaric specific heat capacity has been obtained, in a wide range of temperatures and pressures, for pure water, n -nonane, n -undecane, and rapeseed oil methyl ester. The results have been compared with those available in the literature, when it was possible. Moreover, the typical uncertainty of heat capacity has been estimated to be in the order of 1.5%; however it has been shown that it can be improved when proper distributions of the experimental points are available.

  • A novel application of Recursive Equation Method for determining thermodynamic properties of single phase fluids from density and speed-of-sound measurements
    The Journal of Chemical Thermodynamics, 2013
    Co-Authors: S. Lago, P.a. Giuliano Albo
    Abstract:

    In this work, the authors suggest a preliminary numerical calculation which allows to determine the constant pressure specific heat capacity, starting from density and speed-of-sound experimental values, as input data.\ud This method is a variant of the well characterized Recursive Equation Method (REM) [1] and permits to develop empirical Equations of state for single phase fluids. In particular, the isobaric specific heat capacity has been obtained, in a wide range of temperatures and pressures, for pure water, n-nonane, n-undecane, and rapeseed oil methyl ester. The results have been compared with those available in the literature, when it was possible. Moreover, the typical uncertainty of heat capacity has been estimated to be in the order of 1.5%; however it has been shown that it can be improved when proper distributions of the experimental points are available

  • A Recursive Equation method for the determination of density and heat capacity: Comparison between isentropic and isothermal integration paths
    The Journal of Chemical Thermodynamics, 2010
    Co-Authors: S. Lago, P.a. Giuliano Albo
    Abstract:

    Abstract Among different ways to obtain the thermodynamic properties of a fluid in the liquid phase, there is the possibility to solve, numerically, a system of two differential Equations where density and specific heat capacity are the unknown variables expressed as functions of temperature and pressure. By means of general methods, like Predictor–Corrector or Runge–Kutta, this system can be solved integrating along isothermal paths, once the initial conditions are known along an isobar and the speed of sound values are measured over the p – T region of interest. In this work a new perturbative method, called Recursive Equation method (REM), based on the analytic Recursive determination of the coefficients describing density and specific heat capacity, is proposed. The main advantage of REM is the possibility to also get the value of the uncertainty associated with the solutions, obtained by means of standard methods of error analysis. Another improvement introduced by this algorithm is the possibility to solve the system of Equations following arbitrary integration paths. In particular, a comparison between the results of density and heat capacity, obtained by integrating along isentropic and isothermal paths, is presented, both for water and for acetone.

S. Lago - One of the best experts on this subject based on the ideXlab platform.

  • a novel application of Recursive Equation method for determining thermodynamic properties of single phase fluids from density and speed of sound measurements
    The Journal of Chemical Thermodynamics, 2013
    Co-Authors: S. Lago, P.a. Giuliano Albo
    Abstract:

    Abstract The determination of thermal quantities from mechanical properties is still a challenge in the thermodynamic field. In this work, the authors suggest a preliminary numerical calculation which allows to determine the constant pressure specific heat capacity, starting from density and speed-of-sound experimental values, as input data. This method is a variant of the well characterized Recursive Equation Method (REM) [1] and permits to develop empirical Equations of state for single phase fluids. In particular, the isobaric specific heat capacity has been obtained, in a wide range of temperatures and pressures, for pure water, n -nonane, n -undecane, and rapeseed oil methyl ester. The results have been compared with those available in the literature, when it was possible. Moreover, the typical uncertainty of heat capacity has been estimated to be in the order of 1.5%; however it has been shown that it can be improved when proper distributions of the experimental points are available.

  • A novel application of Recursive Equation Method for determining thermodynamic properties of single phase fluids from density and speed-of-sound measurements
    The Journal of Chemical Thermodynamics, 2013
    Co-Authors: S. Lago, P.a. Giuliano Albo
    Abstract:

    In this work, the authors suggest a preliminary numerical calculation which allows to determine the constant pressure specific heat capacity, starting from density and speed-of-sound experimental values, as input data.\ud This method is a variant of the well characterized Recursive Equation Method (REM) [1] and permits to develop empirical Equations of state for single phase fluids. In particular, the isobaric specific heat capacity has been obtained, in a wide range of temperatures and pressures, for pure water, n-nonane, n-undecane, and rapeseed oil methyl ester. The results have been compared with those available in the literature, when it was possible. Moreover, the typical uncertainty of heat capacity has been estimated to be in the order of 1.5%; however it has been shown that it can be improved when proper distributions of the experimental points are available

  • A Recursive Equation method for the determination of density and heat capacity: Comparison between isentropic and isothermal integration paths
    The Journal of Chemical Thermodynamics, 2010
    Co-Authors: S. Lago, P.a. Giuliano Albo
    Abstract:

    Abstract Among different ways to obtain the thermodynamic properties of a fluid in the liquid phase, there is the possibility to solve, numerically, a system of two differential Equations where density and specific heat capacity are the unknown variables expressed as functions of temperature and pressure. By means of general methods, like Predictor–Corrector or Runge–Kutta, this system can be solved integrating along isothermal paths, once the initial conditions are known along an isobar and the speed of sound values are measured over the p – T region of interest. In this work a new perturbative method, called Recursive Equation method (REM), based on the analytic Recursive determination of the coefficients describing density and specific heat capacity, is proposed. The main advantage of REM is the possibility to also get the value of the uncertainty associated with the solutions, obtained by means of standard methods of error analysis. Another improvement introduced by this algorithm is the possibility to solve the system of Equations following arbitrary integration paths. In particular, a comparison between the results of density and heat capacity, obtained by integrating along isentropic and isothermal paths, is presented, both for water and for acetone.

Lars Birkedal - One of the best experts on this subject based on the ideXlab platform.

  • Transfinite Step-Indexing: Decoupling Concrete and Logical Steps
    2016
    Co-Authors: Kasper Svendsen, Filip Sieczkowski, Lars Birkedal
    Abstract:

    Step-indexing has proven to be a powerful technique for defining logical relations for languages with advanced type systems and models of expressive program logics. In both cases, the model is stratified using natural numbers to solve a Recursive Equation that has no naive solutions. As a result of this stratification, current models require that each unfolding of the Recursive Equation – each logical step – must coincide with a concrete reduction step. This tight coupling is problematic for applications where the number of logical steps cannot be statically bounded. In this paper we demonstrate that this tight coupling between logical and concrete steps is artificial and show how to loosen it using transfinite step-indexing. We present a logical relation that supports an arbitrary but finite number of logical steps for each concrete step.

  • ESOP - Transfinite Step-Indexing: Decoupling Concrete and Logical Steps
    Programming Languages and Systems, 2016
    Co-Authors: Kasper Svendsen, Filip Sieczkowski, Lars Birkedal
    Abstract:

    Step-indexing has proven to be a powerful technique for defining logical relations for languages with advanced type systems and models of expressive program logics. In both cases, the model is stratified using natural numbers to solve a Recursive Equation that has no naive solutions. As a result of this stratification, current models require that each unfolding of the Recursive Equation --- each logical step --- must coincide with a concrete reduction step. This tight coupling is problematic for applications where the number of logical steps cannot be statically bounded. In this paper we demonstrate that this tight coupling between logical and concrete steps is artificial and show how to loosen it using transfinite step-indexing. We present a logical relation that supports an arbitrary but finite number of logical steps for each concrete step.

Kasper Svendsen - One of the best experts on this subject based on the ideXlab platform.

  • Transfinite Step-Indexing: Decoupling Concrete and Logical Steps
    2016
    Co-Authors: Kasper Svendsen, Filip Sieczkowski, Lars Birkedal
    Abstract:

    Step-indexing has proven to be a powerful technique for defining logical relations for languages with advanced type systems and models of expressive program logics. In both cases, the model is stratified using natural numbers to solve a Recursive Equation that has no naive solutions. As a result of this stratification, current models require that each unfolding of the Recursive Equation – each logical step – must coincide with a concrete reduction step. This tight coupling is problematic for applications where the number of logical steps cannot be statically bounded. In this paper we demonstrate that this tight coupling between logical and concrete steps is artificial and show how to loosen it using transfinite step-indexing. We present a logical relation that supports an arbitrary but finite number of logical steps for each concrete step.

  • ESOP - Transfinite Step-Indexing: Decoupling Concrete and Logical Steps
    Programming Languages and Systems, 2016
    Co-Authors: Kasper Svendsen, Filip Sieczkowski, Lars Birkedal
    Abstract:

    Step-indexing has proven to be a powerful technique for defining logical relations for languages with advanced type systems and models of expressive program logics. In both cases, the model is stratified using natural numbers to solve a Recursive Equation that has no naive solutions. As a result of this stratification, current models require that each unfolding of the Recursive Equation --- each logical step --- must coincide with a concrete reduction step. This tight coupling is problematic for applications where the number of logical steps cannot be statically bounded. In this paper we demonstrate that this tight coupling between logical and concrete steps is artificial and show how to loosen it using transfinite step-indexing. We present a logical relation that supports an arbitrary but finite number of logical steps for each concrete step.

Filip Sieczkowski - One of the best experts on this subject based on the ideXlab platform.

  • Transfinite Step-Indexing: Decoupling Concrete and Logical Steps
    2016
    Co-Authors: Kasper Svendsen, Filip Sieczkowski, Lars Birkedal
    Abstract:

    Step-indexing has proven to be a powerful technique for defining logical relations for languages with advanced type systems and models of expressive program logics. In both cases, the model is stratified using natural numbers to solve a Recursive Equation that has no naive solutions. As a result of this stratification, current models require that each unfolding of the Recursive Equation – each logical step – must coincide with a concrete reduction step. This tight coupling is problematic for applications where the number of logical steps cannot be statically bounded. In this paper we demonstrate that this tight coupling between logical and concrete steps is artificial and show how to loosen it using transfinite step-indexing. We present a logical relation that supports an arbitrary but finite number of logical steps for each concrete step.

  • ESOP - Transfinite Step-Indexing: Decoupling Concrete and Logical Steps
    Programming Languages and Systems, 2016
    Co-Authors: Kasper Svendsen, Filip Sieczkowski, Lars Birkedal
    Abstract:

    Step-indexing has proven to be a powerful technique for defining logical relations for languages with advanced type systems and models of expressive program logics. In both cases, the model is stratified using natural numbers to solve a Recursive Equation that has no naive solutions. As a result of this stratification, current models require that each unfolding of the Recursive Equation --- each logical step --- must coincide with a concrete reduction step. This tight coupling is problematic for applications where the number of logical steps cannot be statically bounded. In this paper we demonstrate that this tight coupling between logical and concrete steps is artificial and show how to loosen it using transfinite step-indexing. We present a logical relation that supports an arbitrary but finite number of logical steps for each concrete step.