The Experts below are selected from a list of 138468 Experts worldwide ranked by ideXlab platform
S. L. Weber - One of the best experts on this subject based on the ideXlab platform.
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A timescale analysis of the Northern Hemisphere temperature response to volcanic and solar forcing
Climate of the Past, 2005Co-Authors: S. L. WeberAbstract:The Northern Hemisphere temperature response to volcanic and solar forcing in the time interval 1000?1850 AD is studied using first a set of simulations with an intermediate-complexity climate model, driven by reconstructed forcings. Results are then compared with those obtained from the seven high-resolution reconstructed temperature records for the last millenium that are at present available. Focus of the analysis is on the timescale dependence of the response. Results between the model and the proxy-based reconstructions are remarkably consistent. The response to solar forcing is found to equilibrate at interdecadal timescales, reaching an Equilibrium Value for the regression of 0.2?0.3°C per W/m2. The time interval between volcanic eruptions is typically shorter than the dissipation timescale of the climate system, so that the response to volcanic forcing never equilibrates. As a result, the regression on the volcanic forcing is always lower than the Equilibrium Value and goes to zero for the longest temporal scales. The trends over the pre-anthropogenic period are found to be relatively large in all reconstructed temperature records, given the trends in the reconstructed forcing and the Equilibrium Value for the regression. This is at variance with a recent claim that reconstructed temperature records underestimate climatic variations at multi-centennial timescales.
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A timescale analysis of the NH temperature response to volcanic and solar forcing in the past millenium
Climate of the Past Discussions, 2005Co-Authors: S. L. WeberAbstract:The Northern Hemisphere temperature response to volcanic and solar forcing is studied using first a set of simulations with an intermediate-complexity climate model, driven by reconstructed forcings. Results are than compared with those obtained from the seven high-resolution reconstructed temperature records for the last millenium that are at present available. Focus of the analysis is on the timescale dependence of the response. Results between the model and the proxy-based reconstructions are remarkably consistent. The response to solar forcing is found to equilibrate at interdecadal timescales, reaching an Equilibrium Value for the regression of 0.2-0.3°C per W/m2. The time interval between volcanic eruptions is typically shorter than the dissipation timescale of the climate system, so that the response to volcanic forcing never equilibrates. As a result, the regression on the volcanic forcing is always lower than the Equilibrium Value and goes to zero for the longest temporal scales. The trends over the pre-anthropogenic period are found to be relatively large in all reconstructed temperature records compared to their interdecadal-centennial variability. This is at variance with a recent claim that reconstructed temperature records underestimate climatic variations at multi-centennial scales.
Rudolf Podgornik - One of the best experts on this subject based on the ideXlab platform.
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Out of Equilibrium thermal Casimir effect in a model polarizable material
Physical Review E : Statistical Nonlinear and Soft Matter Physics, 2012Co-Authors: David Dean, Vincent Démery, V. Adrian Parsegian, Rudolf PodgornikAbstract:Relaxation of the thermal Casimir or van der Waals force for a model dielectric medium is investigated. We start with a model of interacting polarization fields with a dynamics that leads to a frequency dependent dielectric constant of the Debye form. In the static limit the usual zero frequency Matsubara mode component of the Casimir force is recovered. We then consider the out of Equilibrium relaxation of the van der Waals force to its Equilibrium Value when two initially uncorrelated dielectric bodies are brought into sudden proximity. It is found that the spatial dependence of the out of Equilibrium force is the same as the Equilibrium one but it has a time dependent amplitude, or Hamaker coefficient, which increases in time to its Equilibrium Value. The final relaxation to the Equilibrium Value is exponential in systems with a single or finite number of polarization field relaxation times. However, in systems, such as those described by the Havriliak-Negami dielectric constant, with a broad distribution of relaxation times, we observe a much slower power law decay to the Equilibrium Value.
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Out-of-Equilibrium relaxation of the thermal Casimir effect in a model polarizable material.
Physical Review E, 2012Co-Authors: David S. Dean, Vincent Démery, V. Adrian Parsegian, Rudolf PodgornikAbstract:Relaxation of the thermal Casimir or van der Waals force (the high temperature limit of the Casimir force) for a model dielectric medium is investigated. We start with a model of interacting polarization fields with a dynamics that leads to a frequency dependent dielectric constant of the Debye form. In the static limit, the usual zero frequency Matsubara mode component of the Casimir force is recovered. We then consider the out-of-Equilibrium relaxation of the van der Waals force to its Equilibrium Value when two initially uncorrelated dielectric bodies are brought into sudden proximity. For the interaction between dielectric slabs, it is found that the spatial dependence of the out-of-Equilibrium force is the same as the Equilibrium one, but it has a time dependent amplitude, or Hamaker coefficient, which increases in time to its Equilibrium Value. The final relaxation of the force to its Equilibrium Value is exponential in systems with a single or finite number of polarization field relaxation times. However, in systems, such as those described by the Havriliak-Negami dielectric constant with a broad distribution of relaxation times, we observe a much slower power law decay to the Equilibrium Value.
A M Khoviv - One of the best experts on this subject based on the ideXlab platform.
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relaxation of a metallic glass to the metastable Equilibrium evidence for the existence of the kauzmann pseudocritical temperature
Applied Physics Letters, 2012Co-Authors: Yu P Mitrofanov, S V Khonik, Artur V. Granato, D.m. Joncich, V A Khonik, A M KhovivAbstract:High-precision isothermal measurements on strongly preannealed metallic glass reveal a decrease of the shear modulus to the metastable Equilibrium Value both in the glassy state far below the glass transition and in the supercooled liquid state near Tg. The results obtained point out the existence of a low-temperature limit for the supercooled liquid, which is known as the Kauzmann pseudocritical temperature [W. Kauzmann, Chem. Rev. 43, 219 (1948)]. This finding experimentally questions the existence of the “Kauzmann paradox,” which is widely discussed in the literature.
E. Rohonczy-boksay - One of the best experts on this subject based on the ideXlab platform.
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Prediction of the Equilibrium Value of a potentiometric signal. Application of the measuring tecnique to molecule-sensitive sensors
Analytica Chimica Acta, 1993Co-Authors: J. Havas, L. Kecskés, E. Rohonczy-boksayAbstract:Abstract A measuring technique suitable for the prediction of the electroanalytical Equilibrium signal of a potentiometric sensor is described, based on the evaluation of asymptotes of the response of the cell and the confidence interval from the signals measured in the so-called information dominant section of the response. The Equilibrium voltage can be evaluated with the great precision by comparing the calculated data with a predetermined threshold Value. The technique was applied to the determination of the Equilibrium signal of a carbon dioxide sensor.
V. Adrian Parsegian - One of the best experts on this subject based on the ideXlab platform.
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Out of Equilibrium thermal Casimir effect in a model polarizable material
Physical Review E : Statistical Nonlinear and Soft Matter Physics, 2012Co-Authors: David Dean, Vincent Démery, V. Adrian Parsegian, Rudolf PodgornikAbstract:Relaxation of the thermal Casimir or van der Waals force for a model dielectric medium is investigated. We start with a model of interacting polarization fields with a dynamics that leads to a frequency dependent dielectric constant of the Debye form. In the static limit the usual zero frequency Matsubara mode component of the Casimir force is recovered. We then consider the out of Equilibrium relaxation of the van der Waals force to its Equilibrium Value when two initially uncorrelated dielectric bodies are brought into sudden proximity. It is found that the spatial dependence of the out of Equilibrium force is the same as the Equilibrium one but it has a time dependent amplitude, or Hamaker coefficient, which increases in time to its Equilibrium Value. The final relaxation to the Equilibrium Value is exponential in systems with a single or finite number of polarization field relaxation times. However, in systems, such as those described by the Havriliak-Negami dielectric constant, with a broad distribution of relaxation times, we observe a much slower power law decay to the Equilibrium Value.
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Out-of-Equilibrium relaxation of the thermal Casimir effect in a model polarizable material.
Physical Review E, 2012Co-Authors: David S. Dean, Vincent Démery, V. Adrian Parsegian, Rudolf PodgornikAbstract:Relaxation of the thermal Casimir or van der Waals force (the high temperature limit of the Casimir force) for a model dielectric medium is investigated. We start with a model of interacting polarization fields with a dynamics that leads to a frequency dependent dielectric constant of the Debye form. In the static limit, the usual zero frequency Matsubara mode component of the Casimir force is recovered. We then consider the out-of-Equilibrium relaxation of the van der Waals force to its Equilibrium Value when two initially uncorrelated dielectric bodies are brought into sudden proximity. For the interaction between dielectric slabs, it is found that the spatial dependence of the out-of-Equilibrium force is the same as the Equilibrium one, but it has a time dependent amplitude, or Hamaker coefficient, which increases in time to its Equilibrium Value. The final relaxation of the force to its Equilibrium Value is exponential in systems with a single or finite number of polarization field relaxation times. However, in systems, such as those described by the Havriliak-Negami dielectric constant with a broad distribution of relaxation times, we observe a much slower power law decay to the Equilibrium Value.