The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Scott T Huxtable - One of the best experts on this subject based on the ideXlab platform.
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the influence of interface bonding on thermal transport through solid liquid interfaces
Applied Physics Letters, 2013Co-Authors: Hari Harikrishna, William A Ducker, Scott T HuxtableAbstract:We use time-domain thermoreflectance to show that interface thermal conductance, G, is proportional to the Thermodynamic Work of adhesion between gold and water, WSL, for a series of five alkane-thiol monolayers at the gold-water interface. WSL is a measure of the bond strength across the solid-liquid interface. Differences in bond strength, and thus differences in WSL, are achieved by varying the terminal group (ω-group) of the alkane-thiol monolayers on the gold. The interface thermal conductance values were in the range 60–190 MW m−2 K−1, and the solid-liquid contact angles span from 25° to 118°.
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The influence of interface bonding on thermal transport through solid–liquid interfaces
Applied Physics Letters, 2013Co-Authors: Hari Harikrishna, William A Ducker, Scott T HuxtableAbstract:We use time-domain thermoreflectance to show that interface thermal conductance, G, is proportional to the Thermodynamic Work of adhesion between gold and water, WSL, for a series of five alkane-thiol monolayers at the gold-water interface. WSL is a measure of the bond strength across the solid-liquid interface. Differences in bond strength, and thus differences in WSL, are achieved by varying the terminal group (ω-group) of the alkane-thiol monolayers on the gold. The interface thermal conductance values were in the range 60–190 MW m−2 K−1, and the solid-liquid contact angles span from 25° to 118°.
Bryce Alexander Roth - One of the best experts on this subject based on the ideXlab platform.
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Method for Propulsion Technology Impact Evaluation via Thermodynamic Work Potential
Journal of Aircraft, 2003Co-Authors: Bryce Alexander Roth, Dimitri N MavrisAbstract:The task of propulsion technology concept selection and integration is one of the most challenging problems in aerospace systems design. This is because of the tightly-coupled and inherently multidisciplinary nature of the problem, as well as the multitude of performance constraints and requirements placed on modern propulsion systems. In addition, as the cost of developing new and improved propulsion systems continues to rise, the attendant risk to the developer increases also. This leads to an aversion to risk that stifles innovation, particularly when it involves the
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Revolutionary/Unconventional Aeropropulsion Technology Evaluation through Thermodynamic Work Potential: A Revolutionary Aeropropulsion Concepts Program Research Initiative
2002Co-Authors: Dimitri N Mavris, Travis W. Danner, Bryce Alexander RothAbstract:This report is intended as a status report for activities covered May through July 2002 under the auspices of NASA Glenn's Revolutionary Aeropropulsion Concepts (RAC) project. This is the first phase I quarterly report and as such, considerable focus will be given to defining the basic need and motivation driving this research effort. In addition, background research has been ongoing for the past several months and has culminated in considerable information pertaining to the state-of-the-art in Work potential analysis methods. This Work is described in detail herein. Finally, the proposed analysis approach is described, as are the various ancillary concepts required for its implementation.
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revolutionary unconventional aeropropulsion technology evaluation through Thermodynamic Work potential a revolutionary aeropropulsion concepts program research initiative
2002Co-Authors: Dimitri N Mavris, Travis W. Danner, Bryce Alexander RothAbstract:This report is intended as a status report for activities covered May through July 2002 under the auspices of NASA Glenn's Revolutionary Aeropropulsion Concepts (RAC) project. This is the first phase I quarterly report and as such, considerable focus will be given to defining the basic need and motivation driving this research effort. In addition, background research has been ongoing for the past several months and has culminated in considerable information pertaining to the state-of-the-art in Work potential analysis methods. This Work is described in detail herein. Finally, the proposed analysis approach is described, as are the various ancillary concepts required for its implementation.
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an investigation of applications for Thermodynamic Work potential methods Working tables and charts for estimation of Thermodynamic Work potential in equilibrium mixtures of jet a and air
2002Co-Authors: Dimitri N Mavris, Bryce Alexander Roth, Robert A McdonaldAbstract:The objective of this report is to provide a tool to facilitate the application of Thermodynamic Work potential methods to aircraft and engine analysis. This starts with a discussion of the theoretical background underlying these methods, which is then used to derive various equations useful for Thermodynamic analysis of aircraft engines. The Work potential analysis method is implemented in the form of a set of Working charts and tables that can be used to graphically evaluate Work potential stored in high-enthalpy gas. The range of validity for these tables is 300 to 36,000 R, pressures between between 0.01 atm and 100 atm, and fuel-air ratios from zero to stoichiometric. The derivations and charts assume mixtures of Jet-A and air as the Working fluid. The Thermodynamic properties presented in these charts were calculated based upon standard Thermodynamic curve fits.
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A Method for Comprehensive Evaluation of Propulsion System Thermodynamic Performance and Loss
37th Joint Propulsion Conference and Exhibit, 2001Co-Authors: Bryce Alexander RothAbstract:This paper develops a method to analyze usage and loss of Thermodynamic Work potential in vehicle propulsion systems. This method is then demonstrated on the Northrop F-5E propulsion system. The result is a Thermodynamic 'loss deck' describing the partitioning of Work potential usage (and loss) as a function of vehicle flight condition and engine power setting. Specifically, three loss deck formulations are demonstrated for the F-5E propulsion system: exergy, gas horsepower, and thrust Work potential. Finally, these three loss decks are compared and contrasted to show their relative merits for propulsion system design and engine/airframe matching applications.
A. M. Jayannavar - One of the best experts on this subject based on the ideXlab platform.
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Fluctuation theorems and atypical trajectories
Journal of Physics A: Mathematical and Theoretical, 2011Co-Authors: Mamata Sahoo, Sourabh Lahiri, A. M. JayannavarAbstract:In this Work, we have studied simple models that can be solved analytically to illustrate various fluctuation theorems. These fluctuation theorems provide symmetries individually to the distributions of physical quantities like the classical Work ($W_c$), Thermodynamic Work ($W$), total entropy ($\Delta s_{tot}$) and dissipated heat ($Q$), when the system is driven arbitrarily out of equilibrium. All these quantities can be defined for individual trajectories. We have studied the number of trajectories which exhibit behaviour unexpected at the macroscopic level. As the time of observation increases, the fraction of such atypical trajectories decreases, as expected at macroscale. Nature of distributions for the Thermodynamic Work and the entropy production in nonlinear models may exhibit peak (most probable value) in the atypical regime without violating the expected average behaviour. However, dissipated heat and classical Work exhibit peak in the regime of typical behaviour only.
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Classical and Thermodynamic Work fluctuations
Indian Journal of Physics, 2010Co-Authors: Mamata Sahoo, A. M. JayannavarAbstract:We have studied the nature of classical Work (W c ) and Thermodynamic Work (W) fluctuations in systems driven out of equilibrium both in transient and time periodic steady state. As the observation time of a large number of trajectories increases, the fraction of trajectories which exhibit excursions away from the typical behaviour, namely, W c < 0, W < Δ F and dissipated heat Q < 0 decreases as anticipated for macroscopic time scales. An analytical expression for such trajectories is obtained. Trajectory for which W c < 0 may not correspond to W < Δ F or Q < 0. The applicability of steady state fluctuation theorems is discussed in our linear as well as nonlinear models.
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classical and Thermodynamic Work fluctuations
arXiv: Classical Physics, 2009Co-Authors: Mamata Sahoo, A. M. JayannavarAbstract:We have studied the nature of classical Work ($W_{c}$) and Thermodynamic Work ($W$) fluctuations in systems driven out of equilibrium both in transient and time periodic steady state. As the observation time of trajectory increases, we show that the number of trajectories which exhibit excursions away from the typical behaviour i.e., $W_{c}<0$, $W<\Delta F$ and dissipated heat $Q<0$ decreases as anticipated for macroscopic time scales. Analytical expressions for such trajectories are obtained. Trajectory for which $W_{c}<0$ may not correspond to $W<\Delta F$ or $Q<0$. The applicability of steady state fluctuation theorems are discussed in our linear as well as nonlinear models.
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nonequilibrium Work distributions for a trapped brownian particle in a time dependent magnetic field
Physical Review E, 2008Co-Authors: Arnab Saha, A. M. JayannavarAbstract:We study the dynamics of a trapped, charged Brownian particle in the presence of a time-dependent magnetic field. We calculate Work distributions for different time-dependent protocols numerically. In our problem, Thermodynamic Work is related to variation of the vector potential with time as opposed to the earlier studies where the Work is related to time variation of the potentials, a quantity that depends only on the coordinates of the particle. Using the Jarzynski and the Crooks equalities, we show that the free energy of the particle is independent of the magnetic field, thus complementing the Bohr-van Leeuwen theorem. We also show that our system exhibits a parametric resonance in a certain parameter space.
Dimitri N Mavris - One of the best experts on this subject based on the ideXlab platform.
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Method for Propulsion Technology Impact Evaluation via Thermodynamic Work Potential
Journal of Aircraft, 2003Co-Authors: Bryce Alexander Roth, Dimitri N MavrisAbstract:The task of propulsion technology concept selection and integration is one of the most challenging problems in aerospace systems design. This is because of the tightly-coupled and inherently multidisciplinary nature of the problem, as well as the multitude of performance constraints and requirements placed on modern propulsion systems. In addition, as the cost of developing new and improved propulsion systems continues to rise, the attendant risk to the developer increases also. This leads to an aversion to risk that stifles innovation, particularly when it involves the
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Revolutionary/Unconventional Aeropropulsion Technology Evaluation through Thermodynamic Work Potential: A Revolutionary Aeropropulsion Concepts Program Research Initiative
2002Co-Authors: Dimitri N Mavris, Travis W. Danner, Bryce Alexander RothAbstract:This report is intended as a status report for activities covered May through July 2002 under the auspices of NASA Glenn's Revolutionary Aeropropulsion Concepts (RAC) project. This is the first phase I quarterly report and as such, considerable focus will be given to defining the basic need and motivation driving this research effort. In addition, background research has been ongoing for the past several months and has culminated in considerable information pertaining to the state-of-the-art in Work potential analysis methods. This Work is described in detail herein. Finally, the proposed analysis approach is described, as are the various ancillary concepts required for its implementation.
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revolutionary unconventional aeropropulsion technology evaluation through Thermodynamic Work potential a revolutionary aeropropulsion concepts program research initiative
2002Co-Authors: Dimitri N Mavris, Travis W. Danner, Bryce Alexander RothAbstract:This report is intended as a status report for activities covered May through July 2002 under the auspices of NASA Glenn's Revolutionary Aeropropulsion Concepts (RAC) project. This is the first phase I quarterly report and as such, considerable focus will be given to defining the basic need and motivation driving this research effort. In addition, background research has been ongoing for the past several months and has culminated in considerable information pertaining to the state-of-the-art in Work potential analysis methods. This Work is described in detail herein. Finally, the proposed analysis approach is described, as are the various ancillary concepts required for its implementation.
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an investigation of applications for Thermodynamic Work potential methods Working tables and charts for estimation of Thermodynamic Work potential in equilibrium mixtures of jet a and air
2002Co-Authors: Dimitri N Mavris, Bryce Alexander Roth, Robert A McdonaldAbstract:The objective of this report is to provide a tool to facilitate the application of Thermodynamic Work potential methods to aircraft and engine analysis. This starts with a discussion of the theoretical background underlying these methods, which is then used to derive various equations useful for Thermodynamic analysis of aircraft engines. The Work potential analysis method is implemented in the form of a set of Working charts and tables that can be used to graphically evaluate Work potential stored in high-enthalpy gas. The range of validity for these tables is 300 to 36,000 R, pressures between between 0.01 atm and 100 atm, and fuel-air ratios from zero to stoichiometric. The derivations and charts assume mixtures of Jet-A and air as the Working fluid. The Thermodynamic properties presented in these charts were calculated based upon standard Thermodynamic curve fits.
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A Method for Propulsion Technology Evaluation Via Thermodynamic Work Potential
8th Symposium on Multidisciplinary Analysis and Optimization, 2000Co-Authors: Bryce Alexander Roth, Dimitri N MavrisAbstract:Presented at the 8th AIAA/USAF/NASA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, Long Beach, CA, September 6-8, 2000.
Terry Rudolph - One of the best experts on this subject based on the ideXlab platform.
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description of quantum coherence in Thermodynamic processes requires constraints beyond free energy
Nature Communications, 2015Co-Authors: Matteo Lostaglio, David Jennings, Terry RudolphAbstract:Recent studies have developed fundamental limitations on nanoscale Thermodynamics, in terms of a set of independent free energy relations. Here we show that free energy relations cannot properly describe quantum coherence in Thermodynamic processes. By casting time-asymmetry as a quantifiable, fundamental resource of a quantum state, we arrive at an additional, independent set of Thermodynamic constraints that naturally extend the existing ones. These asymmetry relations reveal that the traditional Szilard engine argument does not extend automatically to quantum coherences, but instead only relational coherences in a multipartite scenario can contribute to Thermodynamic Work. We find that coherence transformations are always irreversible. Our results also reveal additional structural parallels between Thermodynamics and the theory of entanglement.
